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Sensilla styloconica are elongated microscopically conspicuous chemo-mechano receptors found exclusively at the tongue tip of many adult Lepidoptera. These unique proboscis sensilla were comparatively studied using the scanning electron microscope in 107 species of North American and tropical butterflies. Focus was on 76 species of North American Nymphalidae representing 45 genera and 11 subfamily groups, and 15 species of tropical Nymphalidae representing additional genera and subfamilies. Observations of adult nymphalid feeding behaviour and food preference for correlation with morphological characteristics were made largely in North America and substantially in the Neotropics, where bait traps were used in conjunction with aerial netting. The tongue tips of 16 additional species representing 5 more butterfly families were also examined for the presence and morphological characteristics of sensilla styloconica.
Catalog of the mosses of Japan compiled by the author in 1991 was revised. This new catalog lists all names of genera and species of mosses described or reported from Japan, based on all literature available to the author up to the end of January 2004. The new catalog is comprised of 1,135 species of mosses belonging to 332 genera. These taxa are listed in alphabetical order. Each valid epithet is followed by author citation, literature, distributional area in Japan, and Japanese name.
As for the relation between Islam and pluralism, it seems a little bit complicated. There are some verses in The Koran for pluralism and at the same time we have some verses against. Among the sayings of Prophet Muhammad like the some Koranic verses, we came across with something good and bad for non-Muslims in special contexts. By another saying, we find both positive and negative statements for Jews and Christians in different circumstances. Muslim scholars the complexity still exists. We find both positive and negative stances. So it is difficult to see a standard or official view on this issue. However, we should point out that Islam recognizes all the sacred (Semitic) books and their messages. It accepts all prophets of that traditions. It defines itself as the last and perfect religion of Semitic tradition and states that no other religion will be accepted from anybody else other then itself. It criticizes both the Jews and Christians especially about their failure to uphold the Oneness of God, tawhid, and to preserve the authenticity of their scripture from interventions. This exclusivist aspect of Islam as many conservative scholars formed with putting together some evidences from the Koran is generally accepted by Muslims.
Religious Anthropology studies the origins, evolution and functions of religions. The discipline researching religious beliefs and rituals comparatively with cross-cultural perspectives tries to enlighten the belief world of the mankind. Religion, as a term, can be defined as "believing as well as worshipping to the supernatural powers and/or beings by the individual who are emotionally or consciously devoted to them" (Örnek 1988: 127). There have been a number of theories so far which try to bring an explanation to the origins and the evolution of religion. In these theories, Fetishism, cults of nature, animism, Totemism, dynamism, Manism, magic, polytheism, monotheism as well as certain physiological phenomena have been particularized as evolutionary stages and forms of belief (Evans-Pritchard 1998: 124). All of these theories have the perspective of so called "progressive" and / or "unilinear" that maintain a religion which has reached ongoing stages and that communities which have developed from primitiveness to civilization. They argue that there has only been one single line of progress, and all of the communities are bound to go through the same evolutionary stages.
Untouchability and inter-caste relations in rural India : the case of southern Tamil villages
(2004)
Justice and equality are the two subjects often talked about by most of the nationalists and leaders of various political and ideological streams across the world including India. India was at the fore-front in condemning racial discrimination particularly apartheid and also the influence of super powers) on the internal affairs of independent nations. Her commitment to secure its citizens' freedom, justice, equality and fraternity is reflected in the very preamble of the Indian Constitution. Towards achieving these challenging goals, special provisions have also been made in the Constitution to protect and promote the interests of the most oppressed section of Indian society - traditionally known as Untouchables and Constitutionally as the Scheduled Castes. These provisions are expected to alter the given unjust distribution of power (political and economic) and status (social) among different sections of people and thereby transform India into an egalitarian society. Given India's unequivocal commitment to secure its citizens these noble ideals - particularly the most exploited and pilloried section of India -, we shall attempt here to understand Indian villages, which host over 80 per cent of the Indian population, from the point of view of whether or not these villages patronise the institution of caste which is in contravention of these ideals or whether there are these little republics ideal for realising the said goals and thus to be preserved as they are as claimed by many social reformers including Mahatma Gandhi. In the process, we shall also address the question of how caste has remained unchanged, how it controls social interaction between higher and lower caste groups and accordingly perpetuates unequal control over power and status. And most importantly we shall also understand whether all the Scheduled Castes (lower castes) treat their members as equals or there is hierarchy, discrimination and practice of untouchability even among them.
Safety concerns associated with the use of viral vectors in gene therapy applications have attracted considerable attention towards the development of nonviral vectors as alternatives for DNA delivery. While nonviral vectors are commonly not associated with safety problems, they are still very inefficient compared to viral vectors, and require significant improvements to approach the efficiency of their viral counterparts. Meanwhile ligands or single-chain antibody fragments that bind to cell surface receptors for increased and/or specific cellular uptake, endosome escape activities, and nuclear localization sequences (NLSs) to enhance transport of plasmid DNA into the nucleus, have become available that can be incorporated into nonviral vectors to improve their efficacy. However, as gene delivery is a multistep process, the challenge is to incorporate multiple of these functional elements into a single nonviral vector system, while retaining their specific activities. A promising method to attach such entities to plasmid DNA is the use of multifunctional fusion proteins that bind to DNA through a DNA-binding domain. In principle, two types of DNA-binding domains/proteins can be used to anchor additional functional domains or peptides to a plasmid, namely sequence-specific DNA-binding domains, described in the first part of this thesis, or those that bind DNA independent of its sequence, exemplified in the second part of this work by a derivative of the human HMGB2 protein. The first fusion protein constructed and analyzed contained the E. coli LexA repressor as a sequence-specific DNA-binding domain. In addition, this DNA-carrier protein, termed TEL, included a bacterial translocation domain as an integrated endosome escape activity, and human TGF-a for specific targeting to the EGF-receptor (EGFR). TEL was expressed in E. coli and purified under both native and denaturing conditions. Purified, denatured TEL was refolded and subsequently shown to bind specifically to EGFR-expressing cells. However, inclusion of TEL in complexes of plasmid DNA and poly-L-lysine (pL) did not lead to increased gene delivery into EGFR-expressing COS-1 cells. Most likely this was due to the absence of DNA-binding activity of the LexA moiety in TEL. In contrast, native TEL was able to interact specifically with DNA. Nevertheless, since this interaction was rather weak, and refolding of denatured TEL had not resulted in functional activity of all of its protein domains, it seemed unlikely that fusion proteins containing LexA would exhibit gene transfer capabilities superior to those of similar DNA-carrier proteins previously constructed in our group. Further work therefore focused on the use of the E2C-Sp1C protein as an alternative sequencespecific DNA-binding domain. This artificial zinc-finger protein was fused to the single-chain antibody fragment scFv(FRP5), directed against the human ErbB2 growth factor receptor. The resulting 5-E2C fusion protein was expressed in E. coli and purified under native and denaturing conditions. Refolded and native 5-E2C were found to bind specifically to ErbB2-expressing cells, indicating that scFv(FRP5) in 5-E2C was functional in both preparations. In contrast, whereas refolded 5-E2C bound DNA only weakly, significant DNA binding was observed for native 5-E2C. In addition, it could not only be shown that the interaction of native 5-E2C with DNA containing its recognition sequence was specific, but also that this protein was able to bind DNA and recombinant ErbB2 simultaneously, demonstrating the functionality of both domains in native 5-E2C. Despite these encouraging results, the inclusion of native 5-E2C in pL- or polyethyleneimine (PEI)-DNA complexes did not lead to an (5-E2C-specific) enhancement of gene transfer efficiency, irrespective of the presence of the endosome-disruptive reagent chloroquine during transfection. In the second part of this thesis an alternative approach for the development of DNA-carrier proteins for nonviral gene delivery is described, based on human HMGB2, a DNA-binding protein without sequence specificity. HMGB2 contains an acidic C-terminus that has been found to decrease the affinity of the protein for DNA. Therefore, this C-terminal tail was deleted, resulting in an HMGB2-variant consisting of amino acids 1-186. HMGB2186, purified under native conditions from E. coli lysates, was able to interact with DNA and bound to the surface of different cell lines. Importantly, after binding to plasmid DNA HMGB2186 mediated gene delivery into COS-7 cells with higher efficiency than pL. In addition, HMGB2186-mediated gene transfer was strongly enhanced in the presence of chloroquine, indicating that the endocytic pathway was involved in cellular uptake. To improve internalization and intracellular routing of HMGB2186 as a DNA-carrier, a derivative containing the TAT47-57 cell-penetrating peptide (CPP), reported to facilitate cell entry independent of endocytosis, was constructed. Since this peptide also contains an NLS, in addition an HGMB2186-variant containing the SV40-NLS was constructed to investigate the effect of a peptide that has only nuclear localizing properties. Interestingly, the resulting TAT-HMGB2186 and SV40-HMGB2186 fusion proteins displayed DNA-binding activities similar to HMGB2186, but mediated gene delivery into different cell lines clearly more efficiently than the parental molecule. Furthermore, the efficacy of both fusion proteins was enhanced markedly in the presence of chloroquine, an indication that endocytosis was involved in the transfection process mediated by these proteins. This suggests that the increased transfection efficiency observed for TAT-HMGB2186 was more likely due to the NLS function present in the TAT47-57 peptide, rather than to its ‘cell penetrating properties’. Finally, the incorporation of functional peptides derived from human proteins into HMGB2186 was investigated. An uncharged CPP originating from Kaposi-FGF, reported to facilitate efficient cellular uptake of fused protein domains in an endocytosis-independent manner, was fused to HMGB2186 together with the SV40-NLS. Interestingly, the resulting KSV40-HMGB2186 fusion protein bound DNA similarly as previously tested DNA-carrier proteins, but did not mediate enhanced transfection compared to HMGB2186. In addition, the importin-b-binding (IBB) domain derived from human importin-a2 was investigated as a component of a DNA-carrier protein. Since the IBB domain can function as an NLS, it was fused to HMGB2186 resulting in the DNA-carrier protein IBBHMGB2186. Although IBB-HMGB2186 bound DNA in a similar manner as the other HMGB2186-derivatives, gene delivery mediated by IBB-HMGB2186 was only as effective as HMGB2186 mediated transfection, suggesting no significant role of the IBB domain. However, addition of chloroquine resulted in a remarkable enhancement of IBB-HMGB2186-mediated gene transfer, which was now more efficient than with any other HMGB2186-variant tested, and not much lower than gene transfer mediated by PEI, one of the most efficient transfection reagents available to date. To enhance nonviral gene delivery even further, the HMGB2186-based DNA-carrier proteins described in this thesis might now serve as building blocks for novel fusion proteins that include additional complementing activities. In this respect it seems particularly promising that, under conditions of effective end some escape, IBB-HMGB2186, which consists entirely of protein domains of human origin, was the most efficient of all proteins tested in this work.
RcsB is a central transcriptional regulator in enteric bacteria involved in exopolysaccharide (EPS) biosynthesis, in cell division, in the expression of osmoregulated genes, and regulates at least 20 other genes and operons. It is a member of a phosphorelay system and signal transfer is mediated by phosphorylation through the RcsC/YojN phosphorelay. RcsB proteins modified with the phosphorylation mimic BeF3- as shown by its conformational changes and DNA binding properties and resulted phosphorylated RcsB derivatives with sufficient stability. Both, the wild type RcsB protein and the mutant RcsBD11A could be modified with BeF3-. Non-phosphorylated RcsB has been shown to bind as a heterodimer with the coinducer RcsA at the conserved RcsAB box in Rcs regulated promoters. In this study, it has been shown that the modification of RcsB by BeF3 - (I) has a negative effect on its homodimerization, (II) abolishes the complex formation of RcsAB with the RcsAB box as shown by the EMSA and SPR technique. All the effects were found to be reversible by increasing the NaF concentration in the assays presumably leading to the formation of the inactive BeF4 2- salt. This hypothesis of RcsB being modified by BeF3- was also supported by other phosphodonors like ATP and acetyl phosphate, both of them showed the same negative effect on DNA binding by RcsAB heterodimer giving evidence that BeF3- could be used as a phosphorylation mimic. In addition, the phosphorylation mimic BeF3- was found to be a better phosphorylating agent than ATP and acetyl phosphate. This is the first evidence that phosphorylation of RcsB might have a negative effect on the activation of RcsAB regulated operons. Autophosphorylation of RcsB proves that it has the ability to take up phosphoryl groups and the mutant protein also become autophosphorylated with less efficiency or stability than the wild type protein. RcsB probably takes up phosphoryl groups through RcsC -> YojN -> RcsB phosphorelay pathway. To study the interaction among the proteins in this pathway, fluorescence spectroscopy, NMR spectroscopy, and an in vivo ß galactosidase assay were performed by using two domains of RcsC (T-RcsC and R-RcsC), HPt domain of the protein YojN, and RcsB. The interactions between R-RcsC/YojN-HPt and YojN-HPt/RcsB supports the proposed pathway of phosphorylating RcsB. RcsB might also be phosphorylated by YojN-HPt that is phosphorylated by other sensor kinase other than RcsC in a cross-talk mechanism. The phosphorylation of RcsB by YojN-HPt probably has the same negative effect on cps induction as obtained with BeF3 - effect on DNA binding by RcsAB heterodimer.
The biomarker record in two different lakes in central Europe, Lake Albano and Lake Constance, is used to reflect environmental changes and lake system response during the Late Glacial and Holocene. Extractable organic compounds in lake sediments, which can be assigned to their biological source (biomarkers) function as fingerprints of past aquatic or land plant organisms. Using gas chromatography coupled with mass spectrometry, 21 different biomarkers (predominantly steroids and triterpenoids) as well as a variety of n-alkanes, nalkanols, and n-alkanoic acids could be identified in the sediment records of Lake Albano and Lake Constance. In the Holocene sediments of Lake Albano, the distribution of biomarkers such as dinosterol (dinoflagellates), isoarborinol, and diplopterol (aquatic organisms) indicate three biomarker zones: The period between 0-3,800 years BP (zone 3) is characterized by high concentrations of these biomarkers and others such as tetrahymanol and diploptene. Conversely, zone 2 (3,800-6,500 years BP) shows very low concentrations of all autochthonous biomarkers. In zone 1 (6,500–11,480 years BP), dinosterol, isoarborinol, and diplopterol range on a relatively high level, whereas diploptene and tetrahymanol display comparatively low concentrations. The results suggest at least two distinct changes in the predominance of primary producers during the Holocene, which are related to changes in the lake system such as lake mixing and water column stratification. This interpretation is consistent with previous investigations of Lake Albano sediments including pigment and hydrogen index data (Ariztegui et al., 1996b; Guilizzoni et al., 2002). Allochthonous biomarkers such as long-chain n-alkanes, amyrenones and friedelin indicate a development from forest to a more open landscape from 6,000 and 5.000 years BP, respectively. After a period of high concentrations during the first half of the Holocene, all biomarkers derived from deciduous trees exhibit relatively low values until around 1,000 years BP. Again, this is consistent with results from previous pollen investigations (Ariztegui et al., 2000). The sediment core from Upper Lake Constance comprises the Late Glacial and Holocene. It was analysed for biomarkers and inorganic tracers in order to compare the biomarker results with other proxy data from the same core. Magnetic susceptibility (MS) was measured to get a high-resolution stratigraphic framework of the core and to obtain further information about changes of the proportions of allochthonous and autochthonous input. Enhanced concentrations and accumulation rates of dinosterol (biomarker for dinoflagellates) and biogenic calcite give evidence of increasing lake productivity at the beginning of the Holocene followed by a decrease in bioproductivity after around 7,000 years BP. Younger Dryas sediments are characterized by low amounts of both dinosterol and biogenic calcite indicating a low productivity. The comparison of the concentrations and accumulation rates of b-sitosterol and stigmastanol with parameters reflecting lake productivity suggests that both steroids in Lake Constance sediments are mainly derived from terrigenous sources. Biomarkers as well as concentrations and accumulation rates of allochthonous inorganic compounds such as titanium, magnesium and strontium indicate a slightly enhanced allochthonous input after 8,500 years BP. Significant increase of erosive matter input from enhanced soil erosion is not observed before 4,000 years BP. This can be attributed to the combined effects of precipitation increase as a result of climatic deterioration and anthropogenic deforestation which is consistent with observations from other lakes in Central Europe. The MS record of Lake Constance confirms these results by tracing the climatically induced shifts of more intense bioproduction (low MS caused by increased calcite deposition) during the ‘climatic optimum’. This is followed by increasing input of terrigenous sediment compounds during colder and wetter periods which lead to higher MS values in the lake sediments. The occurrence of tetrahymanol in Lake Constance sediments questions the unambiguous use of tetrahymanol as an indicator for water column stratification. Anaerobic organic macroaggregates within the oxygenated, photic zone of the water column have to be considered as a possible living space for anaerobic microorganisms containing tetrahymanol. The direct comparison of two very different lakes Albano and Constance with respect to biomarkers indicating climate or environmental change provides a contribution to the recent biomarker research for a better understanding of biomarkers in lacustrine sediments.
Much has been written on the success of the Indian software industry, enumerating systemic factors like first-class higher education and research institutions, both public and private; low labour costs, stimulating (state) policies etc. However, although most studies analyzing the 'Indian' software industry cover essentially the South (and West) Indian clusters, this issue has not been tackled explicitly. This paper supplements the economic geography explanations mentioned above with the additional factor social capital, which is not only important within the region, but also in transnational (ethnic) networks linking Indian software clusters with the Silicon Valley. In other words, spatial proximity is complemented with cultural proximity, thereby, extending the system of innovation. The main hypothesis is that some Indian regions are more apt to economic development and innovation due to their higher affinity to education and learning, as well as, their more general openness, which has been a main finding of my interviews. In addition, the transnational networks of Silicon Valley Indians seem to be dominated by South Indians, thus, corroborating the regional clustering of the Indian software industry. JEL Classifications: O30, R12, Z13, L86
Im Zeitalter von Internet und digitaler Wissensvermittlung hat auch die Geschichtswissenschaft die Photographie als Quellenmaterial zur Dokumentation historischer Lebensbedingungen und Ereignisse schätzen gelernt. Neben dem geisteswissenschaftlichen Aspekt solcher Photodokumente gibt es einen technisch-konservatorischen Aspekt.
Anomalous monism and mental causality : on the debate of Donald Davidson’s philosophy of the mental
(2004)
The English version of the first chapter of Erwin Rogler and Gerhard Preyer: Materialismus, anomaler Monismus und mentale Kausalität. Zur gegenwärtigen Philosophie des Mentalen bei Donald Davidson und David Lewis (2001) "Anomaler Monismus und Mentale Kausalität. Ein Beitrag zur Debatte über Donald Davidsons Philosophie des Mentalen" is a contribution to the current debates on the philosophy of the mental and mental causality initiated from Donald Davidson's philosophy with his article "Mental Events" (1970). It is the intent of the English version to give a response to the controversy among American, British and Australian philosophers in the context of a global exchange of ideas on problems understanding the mental. Contents 1. Preliminary Remarks 2. The Critique of Property-Epiphenomenalism and Counterarguments (a) The Enlargement of Nomological Reasoning (b) The Counterfactual Analysis (c) Supervenient Causality 3. Are Mental Properties real or unreal (fictive)? Abstract Things and events are fundamental entities in Davidson's ontology. Less distinct is the ontological status of properties, especially of mental types. Despite of some eliminative allusions there are weighty reasons to understand Davidson's philosophy of mind as including intentional realism. With it, the question of mental causality arises. There are two striking solutions to this problem: the epiphenomenalism of mental properties and the downward causation of mental events. Davidson cannot accept either. He claims to justify the mental as supervenient causality in order to thus integrate it into physicalism (his version of monism). But his argument at best proves the explanatory, not the causal relevance of mental properties. For this and for other reasons, Davidson fails the aspired synthesis of a sufficiently strong physicalism and the autonomy of the mental; a project whose realization is anyhow hard to achieve.
Background and Aim: In Germany, the discharge medication is usually reported to the general practitioner (GP) by an inital short report (SR) /notification (handed over to the patient) and later by a more detailed discharge letter (DL) of the hospital.
Material and Method: We asked N=536 GPs (from Frankfurt/Main and Luebeck) after the typical report format of their patients discharge medication by the local hospitals. The questionnaire asked for 26 items covering (1) the designation of the medication (brand name, generic name) in SR and DL, (2) further specifications e.g. possibilities of generic substitution or supervision of sensible medications, (3) reasons why GPs do not follow the hospitals recommendations and (4) possibilities for an improvement in the medication-related communication between GP and hospitals.
Results: 39% GPs responded sufficiently to the questionnaire. The majority of the GPs (82%) quoted that in the SR only brand names are given (often or ever) and neither the generic name or any further information on generic substitution is available (seldom or never). 65% of the responders quoted that even in the DL only brand names are given. Only 41% of the responders quoted that further treatment relevant specifications are given (often or ever). 95% responded that new medications or change of custom medication is seldom or never explained in the DL and GP were not explicitly informed about relevant medication changes. 58% of the responders quoted economic reasons for re-adjustment of the discharge medication e.g. by generic substitution. The majority of responders (83%) are favouring (useful or very useful) a pre-discharge information (e.g. via fax) about the medication and 54% a hot-line to some relevant person in the hospital when treatment problems emerge. 67% of the responders quoted in favour of regular meetings between GPs and hospital doctors regarding actual pharmacotherapy.
Conclusion: In conclusion, our survey pointed to marked deficiencies in reporting the discharge medication to GPs.
Conflict of interest: None
Background The detection of the new Coranavirus (CoV) causing agent of the severe acute respiratory syndrome (SARS) for diagnostic purposes is still a critical step in prevention of secondary hospital infections. In this respect the PCR for SARS diagnostic is the fastest and most sensitive method and was published very early after the description of the new pathogen by different groups. To evaluate the quality and sensitivity of the SARS PCR performed in diagnostic laboratories all over the world an external quality assurance (EQA) for SARS PCR was initiated by the WHO, the European Network for Diagnostics of "Imported" Viral Diseases (ENIVD) and the Robert Koch-Institut. Methods Therefore 10 samples of inactivated SARS CoV strains isolated in Frankfurt and Hong Kong in different dilutions and negative controls were prepared. The freeze dried samples were send by mail to 62 different laboratories, in 37 countries in Europe and Israel (35), Asia (11), The Americas (11), Australia and New Zealand (4) and Africa (1). The results were returned by email or fax 1 week (13), 2 weeks (14), 3 weeks (6) and later (29) after receiving the material which does not mimic at all the possible speed of this fast method. But this was not considered in the evaluation of these first SARS EQA. Results 44 laboratories showed good or excellent results (26 = 100%, 18 = 90%) and even the 14 laboratories which archived only 80% (10) or 70% (4) correct results are mostly lacking sensitivity. The results of the other 4 laboratories show basic problems in regard to sensitivity, specificity and consistency of results and must be overcome as soon as possible. 4 laboratories seem to have problems with the specificity finding a positive signal in negative samples. The different methods used for preparation of the SARS CoV genome and diagnostic PCR test procedure used by the participating laboratories will be discussed in more detail in the presentation. Conclusion However, in contrast to previous EQAs for Ebola, Lassa and Orthopoxviruses the quality of PCR results was rather good which might be caused by the early publication and distribution of well developed PCR methods. An EQA for evaluation of SARS specific serology is still ongoing, first results will be available beginning of April 2004.
The continuously growing natural killer (NK) cell line NK-92 is highly cytotoxic against malignant cells of various origin without affecting normal human cells. Based on this selectivity, the potential of NK-92 cells for adoptive therapy is currently being investigated in phase I clinical studies. To further enhance the antitumoral activity of NK-92 cells and expand the range of tumor entities suitable for NK-92-based therapies, here by transduction with retroviral vectors we have generated genetically modified NK-92 cells expressing chimeric antigen receptors specific either for the tumor-associated ErbB2 (HER2/neu) antigen or the human Epithelial Cell Adhesion Molecule (Ep-CAM). Both antigens are overexpressed by many tumors of epithelial origin. The chimeric antigen receptors consist of either the ErbB2 specific scFv(FRP5) antibody fragment or the Ep-CAM specific scFv(MOC31), a flexible hinge region derived from CD8, and transmembrane and intracellular regions of the CD3 zeta chain. Transduced NK-92-scFv(FRP5)-zeta or NK-92-scFv(MOC31)-zeta cells express high levels of the fusion proteins on the cell surface as determined by FACS analysis. In europium release assays no difference in cytotoxic activity of NK-92 and transduced NK-92 cells towards ErbB2 or Ep-CAM negative targets was found. However, even at low effector to target ratios transduced NK-92 cells specifically and efficiently lysed established ErbB2 or Ep-CAM expressing tumor cells that were completely resistant to cytolytic activity of parental NK-92 cells. Similarly, ErbB2-positive primary breast cancer cells isolated from pleural effusions of patients with recurrent disease were selectively killed by NK-92-scFv(FRP5)-zeta. In an in vivo model in immunodeficient mice treatment with retargeted NK-92-scFv(FRP5)-zeta, but not parental NK-92 cells resulted in markedly delayed growth of ErbB2 transformed cancer cells. These results demonstrate that efficient retargeting of NK-92 cytotoxicity can be achieved, and might allow the generation of potent cell-based therapeutics for the treatment of ErbB2 and Ep-CAM expressing malignancies. This therapeutic approach might be applicable for a large variety of different cancers where suitable cell surface antigens have been identified.
The receptor tyrosine kinase ErbB2 (HER2) is overexpressed in multiple human tumors of epithelial origin. High ErbB2 expression is functionally involved in tumorigenesis and correlates with poor clinical prognosis. For immunotherapy of ErbB2 expressing tumors, we developed a strategy to supply the tumor cells with costimulatory activity. A bispecific fusion protein was constructed (BIg5), containing the IgV-like domain of huCD86, the CH2/CH3 domain of huIgG1 and the ErbB2-specific single chain antibody fragment scFv(FRP5). A similar fusion protein lacking the CD86 domain (Ig5) was used as a control. Upon binding of BIg5 to ErbB2 on tumor cells, these cells display CD86 on their surface and thus can deliver costimulatory signals for T-cell activation. In addition, NK cells could be activated by CD86 binding to CD28. BIg5 is secreted by eukaryotic cells as a homodimer with increased stability compared to monomers and possibly enhanced costimulatory activity due to crosslinking of CD28 on effector cells. By FACS analysis, specific binding of the scFv(FRP5) domain to ErbB2 as well as CD86 IgV binding to CTLA-4 could be demonstrated. Together with anti-CD3 antibody, BIg5 stimulates proliferation of human CD2-purified lymphocytes in vitro. After binding to ErbB2 on murine Renca-lacZ/ErbB2 tumor cells, about 50% of initially bound BIg5 is still present on the cell surface after 4 hours. For delivery of chimeric fusion proteins in vivo, we used syngeneic, stably transfected HC11 mammary epithelial cells continuously secreting the proteins. Inoculation of these bystander cells close to subcutaneously growing Renca-lacZ/ErbB2 tumors should provide a long-lasting source to achieve high local concentrations of BIg5 at the tumor site. In vivo HC11-BIg5 cells proved to be non-tumorigenic and secreted BIg5 for several weeks, causing a strong anti-BIg5 antibody response. Treatment of established Renca-lacZ/ErbB2 or ErbB2-negative Renca-lacZ tumors by peritumoral inoculation of either HC11-BIg5 or HC11-Ig5 cells led to rejection of all Renca-lacZ/ErbB2, but none of the Renca-lacZ tumors. HC11neo control cells had no effect on tumor growth. Rejection of ErbB2+ tumors led to long-term protection also against subsequent challenge with intravenously injected ErbB2- tumor cells. Intraperitoneal injection of bystander cells secreting the fusion proteins did not lead to tumor regression suggesting that high local concentrations at the tumor site are necessary to target ErbB2 on tumor cells and to overcome elimination of BIg5 or Ig5 by neutralizing antibodies. The CD86 IgV domain of BIg5 did not play a major role in the observed antitumoral immune response suggesting NK-cell mediated ADCC as the initial effector mechanism followed by activation of tumor specific T cells. Targeting of ErbB2 on tumor cells with antibody fusion proteins that interact specifically with the host immune system could be an efficient and specific approach for therapy of solid ErbB2+ tumors.
Tumor-specific T lymphocytes can be regarded as a highly effective mechanism for tumor rejection. A substantial number of T-cell defined tumor antigens including mutated oncoproteins and differentiation antigens have been identified. However, while most spontaneous tumors appear to be antigenic, few are immunogenic. Activation of tumor-specific cytotoxic T cells (CTL) requires presentation of tumor antigens by professional antigen presenting cells (APCs) via MHC I molecules. Due to their crucial role in T-cell activation, APCs are being exploited for active cancer immunotherapy. Present experimental strategies include the incubation of dendritic cells with synthetic, tumor specific peptides to achieve uptake of tumor antigens and presentation in the context of MHC molecules. Alternatively, gene therapeutic approaches are aimed at the endogenous expression of tumor antigens in APCs upon transfer of suitable vector constructs. Our strategy for the presentation of tumor antigens by APCs is based on the intracellular delivery of tumor antigens as part of a fusion protein specifically targeted to APC cell surface receptors. We have constructed prototype molecules that contain a soluble fragment of CTLA-4 for cell binding via interaction with B7 molecules, genetically fused to a protein fragment derived from the tumor-associated antigen ErbB2. To improve uptake and direct the antigenic determinant preferentially to the MHC class I pathway, in one of these protein vaccines also the translocation domain of the bacterial Pseudomonas exotoxin A has been included. In the parental toxin this protein domain facilitates escape from the endosomal compartment to the cytosol upon receptor mediated endocytosis. Here we have investigated the in vitro cell binding activity of such reagents and their antitumoral activity in immunocompetent murine model systems. Specific binding to B7 molecules and uptake of bacterially expressed protein vaccines could be demonstrated. Ex vivo restimulation with an ErbB2-derived peptide of splenocytes from Balb/c mice injected with the fusion proteins resulted in enhanced IFN-gamma production by T cells. Protective and therapeutic effects of ErbB2 protein vaccines were also investigated. Vaccinated animals were protected against subsequent challenge with syngeneic ErbB2 expressing tumor cells. Likewise, s.c. injection of ErbB2 protein vaccines in the vicinity of established tumors resulted in tumor rejection and long lasting protection indicating that immunological memory was induced. Our results suggest that chimeric proteins combining a tumor antigen and specific recognition of APCs in a single molecule are suitable for targeted delivery of antigens to professional APCs and might become valuable tools for cancer immunotherapy.
Das E-Finance Lab publiziert jeweils quartalsweise einen digitalen sowie einen gedruckten Newsletter, die abwechselnd alle sechs Wochen erscheinen. Der digitale Newsletter gibt einen kurzen Überblick über ausgewählte Forschungsarbeiten und nutzt den Einsatz von Hyperlinks zu weiterführenden Informationen. s. http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hebis:30:3-15886 . Der gedruckte Newsletter "EFL quarterly : an E-Finance Lab publication" hingegen beschreibt kompakt und ergebnisorientiert einzelne Forschungsprojekte.
We study the phase diagram of dense, locally neutral three-flavor quark matter as a function of the strange quark mass, the quark chemical potential, and the temperature, employing a general nine-parameter ansatz for the gap matrix. At zero temperature and small values of the strange quark mass, the ground state of matter corresponds to the color-flavor-locked (CFL) phase. At some critical value of the strange quark mass, this is replaced by the recently proposed gapless CFL (gCFL) phase. We also find several other phases, for instance, a metallic CFL (mCFL) phase, a so-called uSC phase where all colors of up quarks are paired, as well as the standard two-flavor color-superconducting (2SC) phase and the gapless 2SC (g2SC) phase.
We discuss gapless colour superconductivity for neutral quark matter in β equilibrium at zero as well as at nonzero temperature. Basic properties of gapless superconductors are reviewed. The current progress and the remaining problems in the understanding of the phase diagram of strange quark matter are discussed.
During the past decade, processes associated with what is popularly though perhaps misleadingly known as globalization have come within the purview of anthropology. Migration and mobility ‐ and the footloose or even rootless social groups that they produce ‐ as well as the worldwide diffusion of commodities, media images, political ideas and practices, technologies and scientific knowledge today are on anthropology's research agenda. As a consequence, received notions about the ways in which culture relates to territory have been abandoned. The term transnationalisation captures cultural processes that stream across the borders of nation states. Anthropologists have been forced to revise the notion that transnationalisation would inevitably bring about a culturally homogenized world. Instead, we are witnessing a surge of greatly increasing cultural diversity. New cultural forms grow out of historically situated articulations of the local and the global. Rather than left-over relics from traditional orders, these are decidedly modern, yet far from uniform. The essay engages the idea of the pluralization of modernities, explores its potential for interdisciplinary research agendas, and also inquires into problematic assumptions underlying this new theoretical concept.
As of today, estimating interest rate reaction functions for the Euro Area is hampered by the short time span since the conduct of a single monetary policy. In this paper we circumvent the common use of aggregated data before 1999 by estimating interest rate reaction functions based on a panel including actual EMU Member States. We find that exploiting the cross-section dimen- sion of a multi-country panel and accounting for cross-country heterogeneity in advance of the single monetary policy pays off with regard to the estimated reaction functions' ability to describe actual interest rate dynamics. We retrieve a panel reaction function which is demonstrated to be a valuable tool for evaluating episodes of monetary policy since 1999. JEL - Klassifikation: E43 , E58 , C33
This paper employs individual bidding data to analyze the empirical performance of the longer term refinancing operations (LTROs) of the European Central Bank (ECB). We investigate how banks’ bidding behavior is related to a series of exogenous variables such as collateral costs, interest rate expectations, market volatility and to individual bank characteristics like country of origin, size, and experience. Panel regressions reveal that a bank’s bidding depends on bank characteristics. Yet, different bidding behavior generally does not translate into differences concerning bidder success. In contrast to the ECB’s main refinancing operations, we find evidence for the winner’s curse effect in LTROs. Our results indicate that LTROs do neither lead to market distortions nor to unfair auction outcomes. JEL classification: E52, D44
Even though tourism has been recognised as an important field for transnational research today, there are few attempts to place tourism in the context of transnational theories or to think about transnationalism from the perspective of tourists. I argue that in researching tourist practices one can add important aspects to transnational approaches. The prerequisites of mobility and interaction for example are the features chosen by backpackers to describe what their Round-The-World-Trip is about. A form of tourism is adopted, or created, that itself confronts many aspects of globalisation: First of all there is the immense dynamic that is involved. Backpackers try to cover as many places and experiences as possible, travelling at high speed. They adopt all kinds of touristic experiences ranging from beach to adventure to culture tourism. They don't focus on a specific area or country but travel the world. They cross national borders perpetually. Additionally they form a transnational network in which they interact with strangers of similar backgrounds (other backpackers, tourist professionals). This network helps them interacting with people from different backgrounds (the socalled hosts or locals). Considering my research Backpackers forge a certain identity from these transnational practices which I want to name globedentity. Globedentity expresses a type of identity construction that not only refers to the individual (I) but reflects the world (globe) in this identity. This globedentity is not fixed but is perpetually re-created and re-defined. It also embraces the increasing popular awareness of globalisation which backpackers, coming from highly educated middle class backgrounds, in particular have identified with. Due to the constant awareness of the latest global social, cultural and economic developments in these educated milieus they know exactly which tools to use to become successful parts of their societies.
I analysed the importance of shell size, shell shape, habitat preferences and availability, experienced climate, active dispersal and influence of Pleistocene glaciations for the range sizes of 37 Western Palaearctic Helicidae s.l. species for which a phylogeny was available. In both cross-species and phylogenetically controlled analyses, the range sizes were positively correlated to climatic tolerance, shell size, active dispersal and influence of Pleistocene glaciations. In addition, range sizes increased significantly with latitude. Multiple regression suggested that, predominantly, the influence of Pleistocene glaciations, tolerance to large annual temperature ranges and shell size influenced the distributional range sizes. Habitat preference, range and availability, active dispersal and shell shape explained no additional variance. The results suggest that the processes influencing species range size of the Helicidae s.l. are mainly related to the climatic shifts after the Pleistocene.
FGF-2, a potent multifunctional and neurotrophic growth factor, is widely expressed in the brain and upregulated in cerebral ischemia. Previous studies have shown that intraventricularly or systemically administered FGF-2 reduces the size of cerebral infarcts. Whether endogenous FGF-2 is beneficial for the outcome of cerebral ischemia has not been investigated. We have used mice with a null mutation of the fgf2 gene to explore the relevance of endogenous FGF-2 in brain ischemia. Focal cerebral ischemia was produced by occlusion of the middle cerebral artery (MCAO). We found a 75% increase in infarct volume in fgf2 knock-out mice versus wild type littermates (P < 0.05). This difference in the extent of ischemic damage was observed after 24 h, and correlated with decreased viability in fgf2 mutant mice following MCA occlusion. Increased infarct volume in fgf2 null mice was associated with a loss of induction in hippocampal BDNF and trkB mRNA expression. These findings indicate that signaling through trkB may contribute to ameliorating brain damage following ischemia and that bdnf and trkB may be target genes of FGF-2. Together, our data provide the first evidence that endogenous FGF-2 is important in coping with ischemic brain damage suggesting fgf2 as one crucial target gene for new therapeutic strategies in brain ischemia.
Taxation and tax policy reform appears on the political agenda in most advanced welfare states in Europe and North America. Of course studies of taxation and tax policy are nothing new and have existed ever since people have paid taxes. The current work is situated in the context of the future of the welfare state and the reinforced international economic and political integration referred to as "globalization." The purpose of this paper is to analyze how globalization is affecting tax policy in advanced welfare states. In comparing the evolution of tax policy in Canada with those in the United States, Germany and Sweden from 1960 to 1995, I will try to review the conventional antiglobalization thesis, i.e., that globalization leads to a "race to the bottom" in revenue and expenditures policies, or as others have called it, a "beggar the neighbour policy" (Tanzi and Bovenberg 1990, 187). ... Conclusion: The empirical data and theoretical models clearly show that globalization is one relatively minor factor among many that explain tax policy reforms. And even that limited influence is mediated by domestic political systems, institutions and constellations of actors. As the data has shown, the conventional globalization thesis of a race to the bottom is not borne out. Tax rates and tax revenues are still increasing, despite the ongoing trend toward international trade integration. Countervailing pressures like the high cost of welfare programs, different parties in government, strong labour unions, and institutional veto players counteract the pressure of globalization on tax policy. As for the future of taxation in Canada, it is more likely to be one of gradual evolution than radical change. Although the data don’t show any downward pressure on tax rates and tax revenues comparatively speaking, there are at least four key factors in Canada that are likely to put pressure on future tax rates, although regional political dynamics and the workings of fiscal federalism suggest that tax reductions will be a higher priority in some provinces than others (Hale 2002). First, neoliberalism will continue to shape fiscal and tax policy, including the role of the tax system in delivering social policies and programs in most parts of Canada. Second, governments that seek to define their own economic and social priorities rather than simply react to events beyond their borders will have to exercise centralized control over budgetary policies and spending levels if they hope to foster the economic growth needed to finance social services in the context of Canada’s changing demographics. Third, the ability of governments to combine the promotion of economic growth and higher living standards will be closely linked to their ability to develop a workable division of responsibilities among federal and provincial governments and with other national governments. Finally, the diffusion of new technologies will continue to transform national and regional economies while giving individuals greater opportunity to avoid government and tax regulations that run contrary to their perceived interests and values. This discussion of determinants that shape tax policy reform has shown that successful management of fiscal and tax policy requires a capacity to set priorities; adapt to changing circumstances; and build a consensus that enables competing economic, social, regional and ideological interests to identify their own well-being in the broader political and economic environment. Tax policy is shaped by many political, economic and social determinants. As Geoffrey Hale correctly concludes, "it should not be surprising if the tax system stubbornly refuses to confirm either economic theories or political ideologies, but reflects past decisions and the policy tradeoffs of the political process" (2002, 71). The notion of tax policy being driven by globalization and forces associated with globalization (both positive and negative) is simply not borne by the facts.
Despite a legal framework being in place for several years, the market share of qualified electronic signatures is disappointingly low. Mobile Signatures provide a new and promising opportunity for the deployment of an infrastructure for qualified electronic signatures. We that SIM-based signatures are the most secure and convenient solution. However, using the SIM-card as a secure signature creation device (SSCD) raises new challenges, because it would contain the user’s private key as well as the subscriber identification. Combining both functions in one card raises the question who will have the control over the keys and certificates. We propose a protocol called Certification on Demand (COD) that separates certification services from subscriber identification information and allows consumers to choose their appropriate certification services and service providers based on their needs. This infrastructure could be used to enable secure mobile brokerage services that can ommit the necessity of TAN lists and therefore allow a better integration of information and transaction services.
Chemically modified bases are frequently used to stabilize nucleic acids, to study the driving forces for nucleic acid structure formation and to tune DNA and RNA hybridization conditions. In particular, fluorobenzene and fluorobenzimidazole base analogues can act as universal bases able to pair with any natural base and to stabilize RNA duplex formation. Although these base analogues are compatible with an A-form RNA geometry, little is known about the influence on the fine structure and conformational dynamics of RNA. In the present study, nano-second molecular dynamics (MD) simulations have been performed to characterize the dynamics of RNA duplexes containing a central 1'-deoxy-1'-(2,4-difluorophenyl)-ß-D-ribofuranose base pair or opposite to an adenine base. For comparison, RNA with a central uridine:adenine pair and a 1'-deoxy-1'-(phenyl)-ß-D-ribofuranose opposite to an adenine was also investigated. The MD simulations indicate a stable overall A-form geometry for the RNAs with base analogues. However, the presence of the base analogues caused a locally enhanced mobility of the central bases inducing mainly base pair shear and opening motions. No stable ‘base-paired’ geometry was found for the base analogue pair or the base analogue:adenine pairs, which explains in part the universal base character of these analogues. Instead, the conformational fluctuations of the base analogues lead to an enhanced accessibility of the bases in the major and minor grooves of the helix compared with a regular base pair.
RDF is widely used in order to catalogue the chaos of data across the internet. But these descriptions must be stored, evaluated, analyzed and verified. This creates the need to search for an environment to realize these aspects and strengthen RDFs influence. InterSystems postrelational database Caché exposes many features that are similar to RDF and provide persistence with semantic part. Some models for relational databases exist but these lack features like object-oriented data-structures and multidimensional variables. The aim of this thesis is to develop an RDF model for Caché that saves RDF data in an object-oriented form. Furthermore an interface for importing RDF data will be presented and implemented.
Background: Cancer gene therapy will benefit from vectors that are able to replicate in tumor tissue and cause a bystander effect. Replication-competent murine leukemia virus (MLV) has been described to have potential as cancer therapeutics, however, MLV infection does not cause a cytopathic effect in the infected cell and viral replication can only be studied by immunostaining or measurement of reverse transcriptase activity. Results: We inserted the coding sequences for green fluorescent protein (GFP) into the proline-rich region (PRR) of the ecotropic envelope protein (Env) and were able to fluorescently label MLV. This allowed us to directly monitor viral replication and attachment to target cells by flow cytometry. We used this method to study viral replication of recombinant MLVs and split viral genomes, which were generated by replacement of the MLV env gene with the red fluorescent protein (RFP) and separately cloning GFP-Env into a retroviral vector. Co-transfection of both plasmids into target cells resulted in the generation of semi-replicative vectors, and the two color labeling allowed to determine the distribution of the individual genomes in the target cells and was indicative for the occurrence of recombination events. Conclusions: Fluorescently labeled MLVs are excellent tools for the study of factors that influence viral replication and can be used to optimize MLV-based replication-competent viruses or vectors for gene therapy.
Left dislocation in Zulu
(2004)
This paper examines left dislocation constructions in Zulu, a Southern Bantu language belonging to the Nguni group (Zone S 40). In Zulu left dislocation configurations, a topic phrase in the beginning of the sentence is linked to a resumptive element within the associated clause. Typically, the resumptive element is an incorporated pronoun (cf. Bresnan & Mchombo 1987), as illustrated by the examples in (1) and (2). In these examples, the object pronoun (in italics) is part of the verbal morphology and agrees with the noun class (gender) of the dislocate. This situation is schematically illustrated in (3), where co-indexation represents agreement: ...
Multiplayer games have become very popular in the PC market. Almost none of the current games are shipped without some support for multiplayer gaming. At the same time mobile devices are becoming more powerful and popularity of games on these platforms increases. However, there are almost no games that support multiplayer gaming despite the multiple options of these devices to connect with each other and build mobile ad hoc networks. Reasons for this lack of multiplayer support are the high diversity of mobile devices as well as the different protocols and their properties that these devices support. With “SmartBlaster” we developed a multiplayer game for several different platforms that is using several different channels (Bluetooth, IrDa, 802.11 and other networks supporting TCP/IP) to communicate between them.
In the present study possible sources and pathways of the gasoline additive methyl tertiary-butyl ether (MTBE) in the aquatic environment in Germany were investigated. The objective of the present study was to clarify some of the questions raised by a previous study on the MTBE situation in Germany. In the USA and Europe 12 million t and 3 million t of MTBE, respectively, are used as gasoline additive. The detection of MTBE in the aquatic environment and the potential risk for drinking water resources led to a phase-out of MTBE as gasoline additive in single states of the USA. Meanwhile there is also an ongoing discussion about the substitution of MTBE in Europe and Germany. The annual usage of MTBE in Germany is about 600,000 t. However, compared to the USA, significant less data exists on the occurrence of MTBE in the aquatic environment in Europe. Because of its physico-chemical properties, MTBE readily vaporizes from gasoline, is water soluble, adsorbs only weakly to the underground matrix and is largely persistent to biological degradation. The toxicity of MTBE remains to be completely investigated, but MTBE in drinking water has low taste- and odor thresholds of 20-40 microgram/L. The present study was conducted by collecting water samples and analyzing them for their MTBE concentrations through a combination of headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The detection limit was 10 ng/L. The method was successfully tested in the framework of an interlaboratory study and showed recoveries of reference values of 89% (74 ng/L) and 104% (256 ng/L). The relative standard deviations were 12% and 6%. The investigation of 83 water samples from 50 community water systems (CWSs) in Germany revealed a detection frequency of 40% and a concentration range of 17-712 ng/L. The detection of MTBE in the drinking water samples could be explained by a groundwater pollution and the pathway river - riverbank filtration - waterworks. Rivers are important drinking water sources. MTBE is emitted into rivers through a variety of sources. In the present study, potential point sources were investigated, i.e. MTBE production sites/refineries/tank farms and groundwater pollutions. For this purpose, the spatial distribution of MTBE in three German rivers with the named potential emission sources located close to the rivers was investigated by analyzing 49 corresponding river water samples. The influence of the potential emission sources groundwater pollution and refinery/tank farm was successfully demonstrated in certain parts of the River Saale and the River Rhine. Increasing MTBE concentrations from 24 ng/L to 379 ng/L and from 73 ng/L to 5 microgram/L, respectively, could be observed in the parts investigated in these two rivers. The identification of such emission sources is important for future modeling. Further sources of MTBE emission into surface water are industrial (non-petrochemical) and municipal sewage plant effluents. In the present study long-term monitoring of water from the River Main (n=67 samples), precipitation (n=89) and industrial (n=34) and municipal sewage plant effluents (n=66) was conducted. The comparison of the data sets revealed that maximum MTBE concentrations in the River Main of up to 1 microgram/L were most possibly due to single industrial effluents with MTBE concentrations of up to 28 microgram/L (measured in this study). The average MTBE content of 66 ng/L in the River Main most probably originated from municipal sewage plant effluents and further industrial effluents. Background concentrations of <30 ng/L could be related to the direct atmospheric input via precipitation. A certain aspect of the atmospheric MTBE input is represented by the input of MTBE into river water or groundwater through snow. In the present study 43 snow samples from 13 different locations were analyzed for their MTBE content. MTBE could be detected in 65% of the urban and rural samples. The concentrations ranged from 11-613 ng/L and were higher than the concentrations in rainwater samples formerly analyzed. Furthermore, a temperature dependency and wash-out effects could be observed. The atmospheric input of MTBE was in part also visible in the analyzed groundwater samples (n=170). The detection frequencies in non-urban and urban wells were 24% and 63%, respectively. The median concentrations were 177 ng/L and 57 ng/L. In wells located in the vicinity of sites with gasoline contaminated groundwater, MTBE concentrations of up to 42 mg/L could be observed. The MTBE emission sources and the different pathways of MTBE in the aquatic environment demonstrated in the present study and other works raise the question whether the use of MTBE in a bulk product like gasoline should be continued in the future. Currently, possible substitutes like ethyl tertiary-butyl ether (ETBE) or ethanol are being discussed.
This dissertation investigates developments in the performance of J. S. Bach’s music in the second half of the 20th century, as reflected in recordings of the Mass in B Minor, BWV 232. It places particular emphasis on issues relating to concepts of expression through performance. Between the 1950s and the 1980s, most Bach performers shared a partial consensus as to what constitutes expression in performance (e.g., intense sound; wide dynamic range; rubato). Arguments against the application of such techniques to Bach’s works were often linked with the view that his music is more “objective” than later repertoires; or, alternatively, that expressive elements in Bach’s music are self-sufficient, and should be not be intensified in performance. Historically-informed performance (HIP), from the late 1960s onwards, has been characterised by greater attention to the inflection of local details (i.e., individual figures and motifs). In terms of expressive intensity, this led to contradictory results. On the one hand, several HIP performances were characterised by a narrow overall dynamic range, light textures, fast tempi and few contrasts; these performances were often considered lightweight. On the other hand, HIP also promoted renewed interest in the practical application of Baroque theories of musical rhetoric, inspiring performances which projected varied intensity within movements. More recently, traditional means of expression have enjoyed renewed prominence. Ostensibly “romantic” features such as broad legati, long-range crescendi and diminuendi, and organic shaping of movements as wholes have been increasingly adopted by HIP musicians. In order to substantiate the narrative outlined above, the significance of the evidence preserved in sound recordings had to be checked against other sources of information. This dissertation is divided into two main parts. The first part focuses on specific “schools” of prominent Bach performers. Complete recordings of the Mass are examined in relation to the biographical and intellectual backgrounds of the main representatives of these schools, their verbally-expressed views on Bach’s music and on their own role as performers, and their style as documented in recordings of other works. The second part examines the performance history of specific movements within the Mass, comparing the interpretations preserved in sound recordings with relevant verbal analyses and commentaries. The dissertation as a whole therefore combines the resources of reception and performance studies. Beyond its specific historical conclusions concerning Bach performance in the post-war era, it also provides specific insights into Bach’s music, its meaning and its role in contemporary culture.
Calcium-activated potassium channels are fundamental regulators of neuron excitability. SK channels are activated by an intracellular increase of Ca++ (such as occurs during an action potential). They have a small single channel conductance (less than 20pS) and show no voltage dependence of activation. To date, there are only a few examples of high-resolution structures of eukaryotic membrane proteins. All of them were purified from natural sources. Since no abundant natural sources of eukaryotic K+ channels are available we overexpressed rSK2 in order to produce the quantities necessary for structural analysis. Unfortunately the Pichia pastoris expression system did not yield sufficient amount of pure protein, mainly because most of the protein was retained by in the ER and was only partially soluble. Subsequently, two constructs were expressed: SK2-FCYENE (containing a specific sequence that promotes surface expression), and SK2-q-CaM a concatamer of SK2 and calmodulin. Although these proved an improvement in terms of solubilisation, little improvement was found in terms of amounts of purified material obtained. For this reason we tested the Semliki Forest virus expression system, since the protein is expressed in a mammalian system where we hoped that it would be trafficked in the same way as in vivo. Using this system it was possible to express rSK2 and solubilise it with several detergents and to achieve much better purification. However, the levels were still not sufficient for high-resolution structural studies, although sufficient for single particle electron microscopy analysis.
This paper evaluates the effects of job creation schemes on the participating individuals in Germany. Since previous empirical studies of these measures have been based on relatively small datasets and focussed on East Germany, this is the first study which allows to draw policy-relevant conclusions. The very informative and exhaustive dataset at hand not only justifies the application of a matching estimator but also allows to take account of threefold heterogeneity. The recently developed multiple treatment framework is used to evaluate the effects with respect to regional, individual and programme heterogeneity. The results show considerable differences with respect to these sources of heterogeneity, but the overall finding is very clear. At the end of our observation period, that is two years after the start of the programmes, participants in job creation schemes have a significantly lower success probability on the labour market in comparison to matched non-participants.
We propose a new framework for modelling the time dependence in duration processes being in force on financial markets. The pioneering ACD model introduced by Engle and Russell (1998) will be extended in a manner that the duration process will be accompanied by an unobservable stochastic process. The Discrete Mixture ACD framework provides us with a general methodology which puts the idea into practice. It is established by introducing a discrete-valued latent regime variable which can be justified in the light of recent market microstructure theories. The empirical application demonstrates its ability to capture specific characteristics of intraday transaction durations while alternative approaches fail. JEL classification: C41, C22, C25, C51, G14.
In recent methodological work the well known ACD approach, originally introduced by Engle and Russell (1998), has been supplemented by the involvement of an unobservable stochastic process which accompanies the underlying process of durations via a discrete mixture of distributions. The Mixture ACD model, emanating from the specialized proposal of De Luca and Gallo (2004), has proved to be a moderate tool for description of financial duration data. The use of one and the same family of ordinary distributions has been common practice until now. Our contribution incites to use the rich parameterized comprehensive family of distributions which allows for interacting different distributional idiosyncrasies. JEL classification: C41, C22, C25, C51, G14
Information literacy is a mosaic of attitudes, understandings, capabilities and knowledge about which there are three myths. The first myth is that it is about the ability to use ICTs to access a wealth of information. The second is that students entering higher education are information literate because student centred, resource based, and ICT focused learning are now pervasive in secondary education. The third myth is that information literacy development can be addressed by library-centric generic approaches. This paper addresses those myths and emphasises the need for information literacy to be recognised as the critical whole of education and societal issue, fundamental to an information-enabled and better world. In formal education, information literacy can only be developed by infusion into curriculum design, pedagogies, and assessment.
Navigating information, facilitating knowledge: the library, the academy, and student learning
(2004)
Understanding the nature and complementarity of the phenomena of information and knowledge lend not only epistemological clarity to their relationship, but also reaffirms the place of the library in the academic mission of knowledge transfer, acquisition, interpretation, and creation. These in turn reassert the legitimacy of the academic library as necessary participant in the teaching enterprise of colleges and universities. Such legitimacy induces an obligation to teach, and that obligation needs to be explored and implemented with adequate vigor and reach. Librarians and the academy must, however, concede that the scope of the task calls for a solution that goes beyond shared responsibilities. Academic libraries should assume a full teaching function even as they continue their exploration and design of activities and programs aimed at reinforcing information literacy in the various disciplines on campus. All must concede that need for collaboration cannot provide grounds for questioning the desirability of autonomous teaching status for the academic library in information literacy education
Abstract: The medium modification of kaon and antikaon masses, compatible with low energy KN scattering data, are studied in a chiral SU(3) model. The mutual interactions with baryons in hot hadronic matter and the e ects from the baryonic Dirac sea on the K( ¯K ) masses are examined. The in-medium masses from the chiral SU(3) e ective model are compared to those from chiral perturbation theory. Furthermore, the influence of these in-medium e ects on kaon rapidity distributions and transverse energy spectra as well as the K, ¯K flow pattern in heavy-ion collision experiments at 1.5 to 2 A·GeV are investigated within the HSD transport approach. Detailed predictions on the transverse momentum and rapidity dependence of directed flow v1 and the elliptic flow v2 are provided for Ni+Ni at 1.93 A·GeV within the various models, that can be used to determine the in-medium K± properties from the experimental side in the near future.
Antibaryons bound in nuclei
(2004)
We study the possibility of producing a new kind of nuclear systems which in addition to ordinary nucleons contain a few antibaryons (B = p, , etc.). The properties of such systems are described within the relativistic mean field model by employing G parity transformed interactions for antibaryons. Calculations are first done for infinite systems and then for finite nuclei from 4He to 208Pb. It is demonstrated that the presence of a real antibaryon leads to a strong rearrangement of a target nucleus resulting in a significant increase of its binding energy and local compression. Noticeable e ects remain even after the antibaryon coupling constants are reduced by factor 3 4 compared to G parity motivated values. We have performed detailed calculations of the antibaryon annihilation rates in the nuclear environment by applying a kinetic approach. It is shown that due to significant reduction of the reaction Q values, the in medium annihilation rates should be strongly suppressed leading to relatively long lived antibaryon nucleus systems. Multi nucleon annihilation channels are analyzed too. We have also estimated formation probabilities of bound B + A systems in pA reactions and have found that their observation will be feasible at the future GSI antiproton facility. Several observable signatures are proposed. The possibility of producing multi quark antiquark clusters is discussed. PACS numbers: 25.43.+t, 21.10.-k, 21.30.Fe, 21.80.+a
We study the phase diagram of a generalized chiral SU(3)-flavor model in mean-field approxi- mation. In particular, the influence of the baryon resonances, and their couplings to the scalar and vector fields, on the characteristics of the chiral phase transition as a function of temperature and baryon-chemical potential is investigated. Present and future finite-density lattice calculations might constrain the couplings of the fields to the baryons. The results are compared to recent lattice QCD calculations and it is shown that it is non-trivial to obtain, simultaneously, stable cold nuclear matter.
A critical discussion of the present status of the CERN experiments on charm dynamics and hadron collective flow is given. We emphasize the importance of the flow excitation function from 1 to 50 A·GeV: here the hydrodynamic model has predicted the collapse of the v1-flow and of the v2-flow at 10 A·GeV; at 40 A·GeV it has been recently observed by the NA49 collaboration. Since hadronic rescattering models predict much larger flow than observed at this energy we interpret this observation as potential evidence for a first order phase transition at high baryon density B. A detailed discussion of the collective flow as a barometer for the equation of state (EoS) of hot dense matter at RHIC follows. Here, hadronic rescattering models can explain < 30% of the observed elliptic flow, v2, for pT > 2 GeV/c. This is interpreted as evidence for the production of superdense matter at RHIC with initial pressure far above hadronic pressure, p > 1 GeV/fm3. We suggest that the fluctuations in the flow, v1 and v2, should be measured in future since ideal hydrodynamics predicts that they are larger than 50 % due to initial state fluctuations. Furthermore, the QGP coe cient of viscosity may be determined experimentally from the fluctuations observed. The connection of v2 to jet suppression is examined. It is proven experimentally that the collective flow is not faked by minijet fragmentation. Additionally, detailed transport studies show that the awayside jet suppression can only partially (< 50%) be due to hadronic rescattering. We, finally, propose upgrades and second generation experiments at RHIC which inspect the first order phase transition in the fragmentation region, i.e. at µB 400 MeV (y 4 5), where the collapse of the proton flow should be seen in analogy to the 40 A·GeV data. The study of Jet-Wake-riding potentials and Bow shocks caused by jets in the QGP formed at RHIC can give further information on the equation of state (EoS) and transport coe cients of the Quark Gluon Plasma (QGP).
A scenario of heavy resonances, called massive Hagedorn states, is proposed which exhibits a fast (t H 1 fm/c) chemical equilibration of (strange) baryons and anti-baryons at the QCD critical temperature Tc. For relativistic heavy ion collisions this scenario predicts that hadronization is followed by a brief expansion phase during which the equilibration rate is higher than the expansion rate, so that baryons and antibaryons reach chemical equilibrium before chemical freeze-out occurs. PACS-Nr.: 12.38.Mh
The wave function of a spheroidal harmonic oscillator without spin-orbit interaction is expressed in terms of associated Laguerre and Hermite polynomials. The pairing gap and Fermi energy are found by solving the BCS system of two equations. Analytical relationships for the matrix elements of inertia are obtained function of the main quantum numbers and potential derivative. They may be used to test complex computer codes one should develop in a realistic approach of the fission dynamics. The results given for the 240 Pu nucleus are compared with a hydrodynamical model. The importance of taking into account the correction term due to the variation of the occupation number is stressed.
Complex fission phenomena
(2004)
Complex fission phenomena are studied in a unified way. Very general reflection asymmetrical equilibrium (saddle point) nuclear shapes are obtained by solving an integro-differential equation without being necessary to specify a certain parametrization. The mass asymmetry in binary cold fission of Th and U isotopes is explained as the result of adding a phenomenological shell correction to the liquid drop model deformation energy. Applications to binary, ternary, and quaternary fission are outlined.
A very general saddle point nuclear shape may be found as a solution of an integro-differential equation without giving apriori any shape parametrization. By introducing phenomenological shell corrections one obtains minima of deformation energy for binary fission of parent nuclei at a finite (non-zero) mass asymmetry. Results are presented for reflection asymmetric saddle point shapes of thorium and uranium even-mass isotopes with A=226-238 and A=230-238 respectively.
We show that an unambiguous way of determining the universal limiting fragmentation region is to consider the derivative (d 2 n / d eta 2) of the pseudo-rapidity distribution per participant pair. In addition, we find that the transition region between the fragmentation and the central plateau regions exhibits a second kind of universal behavior that is only apparent in d 2 n / d eta 2. The sqrt s dependence of the height of the central plateau (d n / d eta) eta=0 and the total charged particle multiplicity n total critically depend on the behavior of this universal transition curve. Analyzing available RHIC data, we show that (dn/d eta) eta=0 can be bounded by ln 2 s and n total can be bounded by ln 3 s. We also show that the deuteron-gold data from RHIC has the exactly same features as the gold-gold data indicating that these universal behaviors are a feature of the initial state parton-nucleus interactions and not a consequence of final state interactions. Predictions for LHC energy are also given.
We discuss modifications of the gyromagnetic moment of electrons and muons due to a minimal length scale combined with a modified fundamental scaleMf . First-order deviations from the theoretical standard model value for g-2 due to these String Theory-motivated e ects are derived. Constraints for the new fundamental scale Mf are given.
String theory suggests modifications of our spacetime such as extra dimensions and the existence of a mininal length scale. In models with addidional dimensions, the Planck scale can be lowered to values accessible by future colliders. Effective theories which extend beyond the standart-model by including extra dimensions and a minimal length allow computation of observables and can be used to make testable predictions. Expected effects that arise within these models are the production of gravitons and black holes. Furthermore, the Planck-length is a lower bound to the possible resolution of spacetime which might be reached soon.
We compare multiplicities as well as rapidity and transverse momentum distributions of protons, pions and kaons calculated within presently available transport approaches for heavy ion collisions around 1 AGeV. For this purpose, three reactions have been selected: Au+Au at 1 and 1.48 AGeV and Ni+Ni at 1.93 AGeV.
Course management software : supporting the university’s teaching with technology initiatives
(2004)
An increasingly important element of the teaching with technology activities at Northwestern University is the course management system, a web-based class communication and administration environment. The usage growth of the system is substantial and amplifies the need for integration with other web services and resources. Integration is particularly material in area of library services. This presentation contains a case study of Northwestern University's implementation of its course management system software and highlights examples of how the system is being used to enhance the teaching and learning. A description of the integration efforts with library resources is provided. The goal of the presentation is to equip librarians with the basic knowledge required to engage with their colleagues in conversations surrounding the nature of integration of these systems within the teaching and learning landscapes of their home institutions.
The key hypothesis is that the IT industry lure us into the IT world with a promise to solve our information problems. Do we sign the contract, we will recognise that the IT industry can´t keep the promise. One reason: they themselves lost sight over there own game. Therefore they have to invent new tools continiously. LIS professionals should not leave the field IT professionals. LIS professional should rather put stress on to reveal the difference in the value chain between data – information – knowledge. Information and knowledge is brainware and not produced by hard and software in the sense of IT philosophy. Against the background of the language game of Jean-François Lyotard, the author explains the information and knowledge society as language game invented by the IT industry. Furthermore his beliefs of postmodernen LIS professionals and the consequences involved for LIS traning will be presented.
A version of this paper was originally written for a plenary session about "The Futures of Ethnography" at the 1998 EASA conference in Frankfurt/Main. In the preparation of the paper, I sent out some questions to my former fellow researchers by e-mail. I thank Douglas Anthony, Jan-Patrick Heiß, Alaine Hutson, Matthias Krings, and Brian Larkin for their answers.
Evidence for an exotic S=-2, Q=-2 baryon resonance in proton-proton collisions at the CERN SPS
(2004)
Results of resonance searches in the Xi - pi -, Xi - pi +, Xi -bar+ pi -, and Xi -bar+ pi + invariant mass spectra in proton-proton collisions at sqrt[s]=17.2 GeV are presented. Evidence is shown for the existence of a narrow Xi - pi - baryon resonance with mass of 1.862±0.002 GeV/c2 and width below the detector resolution of about 0.018 GeV/c2. The significance is estimated to be above 4.2 sigma . This state is a candidate for the hypothetical exotic Xi --3/2 baryon with S=-2, I=3 / 2, and a quark content of (dsdsu-bar). At the same mass, a peak is observed in the Xi - pi + spectrum which is a candidate for the Xi 03/2 member of this isospin quartet with a quark content of (dsusd-bar). The corresponding antibaryon spectra also show enhancements at the same invariant mass.
Results on high transverse momentum charged particle emission with respect to the reaction plane are presented for Au+Au collisions at sqrt[sNN]=200 GeV. Two- and four-particle correlations results are presented as well as a comparison of azimuthal correlations in Au+Au collisions to those in p+p at the same energy. The elliptic anisotropy v2 is found to reach its maximum at pt~3 GeV/c, then decrease slowly and remain significant up to pt ~ 7-10 GeV/c. Stronger suppression is found in the back-to-back high-pt particle correlations for particles emitted out of plane compared to those emitted in plane. The centrality dependence of v2 at intermediate pt is compared to simple models based on jet quenching.
Azimuthally sensitive Hanbury Brown-Twiss interferometry in Au+Au collisions at sqrt[sNN]=200 GeV
(2004)
We present the results of a systematic study of the shape of the pion distribution in coordinate space at freeze-out in Au+Au collisions at BNL RHIC using two-pion Hanbury Brown-Twiss (HBT) interferometry. Oscillations of the extracted HBT radii versus emission angle indicate sources elongated perpendicular to the reaction plane. The results indicate that the pressure and expansion time of the collision system are not sufficient to completely quench its initial shape.
The pseudorapidity asymmetry and centrality dependence of charged hadron spectra in d+Au collisions at sqrt[sNN ]=200 GeV are presented. The charged particle density at midrapidity, its pseudorapidity asymmetry, and centrality dependence are reasonably reproduced by a multiphase transport model, by HIJING, and by the latest calculations in a saturation model. Ratios of transverse momentum spectra between backward and forward pseudorapidity are above unity for pT below 5 GeV/c . The ratio of central to peripheral spectra in d+Au collisions shows enhancement at 2< pT <6 GeV/c , with a larger effect at backward rapidity than forward rapidity. Our measurements are in qualitative agreement with gluon saturation and in contrast to calculations based on incoherent multiple partonic scatterings.
Transverse energy ( ET ) distributions have been measured for Au+Au collisions at sqrt[sNN ]=200 GeV by the STAR Collaboration at RHIC. ET is constructed from its hadronic and electromagnetic components, which have been measured separately. ET production for the most central collisions is well described by several theoretical models whose common feature is large energy density achieved early in the fireball evolution. The magnitude and centrality dependence of ET per charged particle agrees well with measurements at lower collision energy, indicating that the growth in ET for larger collision energy results from the growth in particle production. The electromagnetic fraction of the total ET is consistent with a final state dominated by mesons and independent of centrality.
We report inclusive photon measurements about midrapidity ( |y| <0.5 ) from 197 Au + 197 Au collisions at sqrt[sNN ]=130 GeV at RHIC. Photon pair conversions were reconstructed from electron and positron tracks measured with the Time Projection Chamber (TPC) of the STAR experiment. With this method, an energy resolution of Delta E/E ~ 2% at 0.5 GeV has been achieved. Reconstructed photons have also been used to measure the transverse momentum ( pt ) spectra of pi 0 mesons about midrapidity ( |y| <1 ) via the pi 0 --> gamma gamma decay channel. The fractional contribution of the pi 0 --> gamma gamma decay to the inclusive photon spectrum decreases by 20%±5% between pt =1.65 GeV/c and pt =2.4 GeV/c in the most central events, indicating that relative to pi 0 --> gamma gamma decay the contribution of other photon sources is substantially increasing.
We present STAR measurements of charged hadron production as a function of centrality in Au+Au collisions at sqrt[sNN ]=130 GeV . The measurements cover a phase space region of 0.2< pT <6.0 GeV/c in transverse momentum and -1< eta <1 in pseudorapidity. Inclusive transverse momentum distributions of charged hadrons in the pseudorapidity region 0.5< | eta | <1 are reported and compared to our previously published results for | eta | <0.5 . No significant difference is seen for inclusive pT distributions of charged hadrons in these two pseudorapidity bins. We measured dN/d eta distributions and truncated mean pT in a region of pT > pcutT , and studied the results in the framework of participant and binary scaling. No clear evidence is observed for participant scaling of charged hadron yield in the measured pT region. The relative importance of hard scattering processes is investigated through binary scaling fraction of particle production.
We report on the rapidity and centrality dependence of proton and antiproton transverse mass distributions from 197Au + 197Au collisions at sqrt[sNN ]=130 GeV as measured by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). Our results are from the rapidity and transverse momentum range of |y| <0.5 and 0.35< pt <1.00 GeV/c . For both protons and antiprotons, transverse mass distributions become more convex from peripheral to central collisions demonstrating characteristics of collective expansion. The measured rapidity distributions and the mean transverse momenta versus rapidity are flat within |y| <0.5 . Comparisons of our data with results from model calculations indicate that in order to obtain a consistent picture of the proton (antiproton) yields and transverse mass distributions the possibility of prehadronic collective expansion may have to be taken into account.
We present data on e+ e- pair production accompanied by nuclear breakup in ultraperipheral gold-gold collisions at a center of mass energy of 200 GeV per nucleon pair. The nuclear breakup requirement selects events at small impact parameters, where higher-order diagrams for pair production should be enhanced. We compare the data with two calculations: one based on the equivalent photon approximation, and the other using lowest-order quantum electrodynamics (QED). The data distributions agree with both calculations, except that the pair transverse momentum spectrum disagrees with the equivalent photon approach. We set limits on higher-order contributions to the cross section.
The transverse mass spectra and midrapidity yields for Xi s and Omega s are presented. For the 10% most central collisions, the Xi -bar+/h- ratio increases from the Super Proton Synchrotron to the Relativistic Heavy Ion Collider energies while the Xi -/h- stays approximately constant. A hydrodynamically inspired model fit to the Xi spectra, which assumes a thermalized source, seems to indicate that these multistrange particles experience a significant transverse flow effect, but are emitted when the system is hotter and the flow is smaller than values obtained from a combined fit to pi , K, p, and Lambda s.
Measurements of the production of forward high-energy pi 0 mesons from transversely polarized proton collisions at sqrt[s]=200 GeV are reported. The cross section is generally consistent with next-to-leading order perturbative QCD calculations. The analyzing power is small at xF below about 0.3, and becomes positive and large at higher xF, similar to the trend in data at sqrt[s] <= 20 GeV. The analyzing power is in qualitative agreement with perturbative QCD model expectations. This is the first significant spin result seen for particles produced with pT>1 GeV/c at a polarized proton collider.
Transverse mass and rapidity distributions for charged pions, charged kaons, protons, and antiprotons are reported for sqrt[sNN]=200 GeV pp and Au+Au collisions at Relativistic Heary Ion Collider (RHIC). Chemical and kinetic equilibrium model fits to our data reveal strong radial flow and long duration from chemical to kinetic freeze-out in central Au+Au collisions. The chemical freeze-out temperature appears to be independent of initial conditions at RHIC energies.
We report results on rho (770)0--> pi + pi - production at midrapidity in p+p and peripheral Au+Au collisions at sqrt[sNN]=200 GeV. This is the first direct measurement of rho (770)0--> pi + pi - in heavy-ion collisions. The measured rho 0 peak in the invariant mass distribution is shifted by ~40 MeV/c2 in minimum bias p+p interactions and ~70 MeV/c2 in peripheral Au+Au collisions. The rho 0 mass shift is dependent on transverse momentum and multiplicity. The modification of the rho 0 meson mass, width, and shape due to phase space and dynamical effects are discussed.
We report the first observations of the first harmonic (directed flow, v1) and the fourth harmonic (v4), in the azimuthal distribution of particles with respect to the reaction plane in Au+Au collisions at the BNL Relativistic Heavy Ion Collider (RHIC). Both measurements were done taking advantage of the large elliptic flow (v2) generated at RHIC. From the correlation of v2 with v1 it is determined that v2 is positive, or in-plane. The integrated v4 is about a factor of 10 smaller than v2. For the sixth (v6) and eighth (v8) harmonics upper limits on the magnitudes are reported.
We present STAR measurements of the azimuthal anisotropy parameter v2 and the binary-collision scaled centrality ratio RCP for kaons and lambdas ( Lambda + Lambda -bar) at midrapidity in Au+Au collisions at sqrt[sNN]=200 GeV. In combination, the v2 and RCP particle-type dependencies contradict expectations from partonic energy loss followed by standard fragmentation in vacuum. We establish pT ~ 5 GeV/c as the value where the centrality dependent baryon enhancement ends. The K0S and Lambda + Lambda -bar v2 values are consistent with expectations of constituent-quark-number scaling from models of hadron formation by parton coalescence or recombination.
Hackethal and Schmidt (2003) criticize a large body of literature on the financing of corporate sectors in different countries that questions some of the distinctions conventionally drawn between financial systems. Their criticism is directed against the use of net flows of finance and they propose alternative measures based on gross flows which they claim re-establish conventional distinctions. This paper argues that their criticism is invalid and that their alternative measures are misleading. There are real issues raised by the use of aggregate data but they are not the ones discussed in Hackethal and Schmidt’s paper. JEL Classification: G30
In contrast to the United States and the United Kingdom, little empirical work exists about the distributional characteristics of appraisalbased real estate returns outside these countries. The purpose of this study is to fill this gap by focusing on Germany. In line with other studies, this paper offers an extensive investigation into the distribution of German real estate returns and compares them with and U.S. and U.K. data in the same period. Furthermore, the comovements with bonds and stocks are also examined. In the core, the distributional characteristics for German real estate are comparable to that for the U.S. and U.K.
Open source projects produce goods or standards that do not allow for the appropriation of private returns by those who contribute to their production. In this paper we analyze why programmers will nevertheless invest their time and effort to code open source software. We argue that the particular way in which open source projects are managed and especially how contributions are attributed to individual agents, allows the best programmers to create a signal that more mediocre programmers cannot achieve. Through setting themselves apart they can turn this signal into monetary rewards that correspond to their superior capabilities. With this incentive they will forgo the immediate rewards they could earn in software companies producing proprietary software by restricting the access to the source code of their product. Whenever institutional arrangements are in place that enable the acquisition of such a signal and the subsequent substitution into monetary rewards, the contribution to open source projects and the resulting public good is a feasible outcome that can be explained by standard economic theory.
In this paper, we calculate a transaction–based price index for apartments in Paris (France). The heterogeneous character of real estate is taken into account using an hedonic model. The functional form is specified using a general Box–Cox function. The data basis covers 84 686 transactions of the housing market in 1990:01–1999:12, which is one of the largest samples ever used in comparable studies. Low correlations of the price index with stock and bond indices (first differences) indicate diversification benefits from the inclusion of real estate in a mixed asset portfolio. JEL C43, C51, O18, R20.
The paper is a follow-up to an article published in Technique Financière et Developpement in 2000 (see the appendix to the hardcopy version), which portrayed the first results of a new strategy in the field of development finance implemented in South-East Europe. This strategy consists in creating microfinance banks as greenfield investments, that is, of building up new banks which specialise in providing credit and other financial services to micro and small enterprises, instead of transforming existing credit-granting NGOs into formal banks, which had been the dominant approach in the 1990s. The present paper shows that this strategy has, in the course of the last five years, led to the emergence of a network of microfinance banks operating in several parts of the world. After discussing why financial sector development is a crucial determinant of general social and economic development and contrasting the new strategy to former approaches in the area of development finance, the paper provides information about the shareholder composition and the investment portfolio of what is at present the world's largest and most successful network of microfinance banks. This network is a good example of a well-functioning "private public partnership". The paper then provides performance figures and discusses why the creation of such a network seems to be a particularly promising approach to the creation of financially self-sustaining financial institutions with a clear developmental objective.
This paper provides an in-depth analysis of the properties of popular tests for the existence and the sign of the market price of volatility risk. These tests are frequently based on the fact that for some option pricing models under continuous hedging the sign of the market price of volatility risk coincides with the sign of the mean hedging error. Empirically, however, these tests suffer from both discretization error and model mis-specification. We show that these two problems may cause the test to be either no longer able to detect additional priced risk factors or to be unable to identify the sign of their market prices of risk correctly. Our analysis is performed for the model of Black and Scholes (1973) (BS) and the stochastic volatility (SV) model of Heston (1993). In the model of BS, the expected hedging error for a discrete hedge is positive, leading to the wrong conclusion that the stock is not the only priced risk factor. In the model of Heston, the expected hedging error for a hedge in discrete time is positive when the true market price of volatility risk is zero, leading to the wrong conclusion that the market price of volatility risk is positive. If we further introduce model mis-specification by using the BS delta in a Heston world we find that the mean hedging error also depends on the slope of the implied volatility curve and on the equity risk premium. Under parameter scenarios which are similar to those reported in many empirical studies the test statistics tend to be biased upwards. The test often does not detect negative volatility risk premia, or it signals a positive risk premium when it is truly zero. The properties of this test furthermore strongly depend on the location of current volatility relative to its long-term mean, and on the degree of moneyness of the option. As a consequence tests reported in the literature may suffer from the problem that in a time-series framework the researcher cannot draw the hedging errors from the same distribution repeatedly. This implies that there is no guarantee that the empirically computed t-statistic has the assumed distribution. JEL: G12, G13 Keywords: Stochastic Volatility, Volatility Risk Premium, Discretization Error, Model Error
In a framework closely related to Diamond and Rajan (2001) we characterize different financial systems and analyze the welfare implications of different LOLR-policies in these financial systems. We show that in a bank-dominated financial system it is less likely that a LOLR-policy that follows the Bagehot rules is preferable. In financial systems with rather illiquid assets a discretionary individual liquidity assistance might be welfare improving, while in market-based financial systems, with rather liquid assets in the banks' balance sheets, emergency liquidity assistance provided freely to the market at a penalty rate is likely to be efficient. Thus, a "one size fits all"-approach that does not take the differences of financial systems into account is misguiding. JEL - Klassifikation: D52 , E44 , G21 , E52 , E58
When options are traded, one can use their prices and price changes to draw inference about the set of risk factors and their risk premia. We analyze tests for the existence and the sign of the market prices of jump risk that are based on option hedging errors. We derive a closed-form solution for the option hedging error and its expectation in a stochastic jump model under continuous trading and correct model specification. Jump risk is structurally different from, e.g., stochastic volatility: there is one market price of risk for each jump size (and not just \emph{the} market price of jump risk). Thus, the expected hedging error cannot identify the exact structure of the compensation for jump risk. Furthermore, we derive closed form solutions for the expected option hedging error under discrete trading and model mis-specification. Compared to the ideal case, the sign of the expected hedging error can change, so that empirical tests based on simplifying assumptions about trading frequency and the model may lead to incorrect conclusions.
This paper deals with the superhedging of derivatives and with the corresponding price bounds. A static superhedge results in trivial and fully nonparametric price bounds, which can be tightened if there exists a cheaper superhedge in the class of dynamic trading strategies. We focus on European path-independent claims and show under which conditions such an improvement is possible. For a stochastic volatility model with unbounded volatility, we show that a static superhedge is always optimal, and that, additionally, there may be infinitely many dynamic superhedges with the same initial capital. The trivial price bounds are thus the tightest ones. In a model with stochastic jumps or non-negative stochastic interest rates either a static or a dynamic superhedge is optimal. Finally, in a model with unbounded short rates, only a static superhedge is possible.
Empirical evidence suggests that even those firms presumably most in need of monitoringintensive financing (young, small, and innovative firms) have a multitude of bank lenders, where one may be special in the sense of relationship lending. However, theory does not tell us a lot about the economic rationale for relationship lending in the context of multiple bank financing. To fill this gap, we analyze the optimal debt structure in a model that allows for multiple but asymmetric bank financing. The optimal debt structure balances the risk of lender coordination failure from multiple lending and the bargaining power of a pivotal relationship bank. We show that firms with low expected cash-flows or low interim liquidation values of assets prefer asymmetric financing, while firms with high expected cash-flow or high interim liquidation values of assets tend to finance without a relationship bank. JEL - Klassifikation: G21 , G78 , G33
This paper suggests a motive for bank mergers that goes beyond alleged and typically unverifiable scale economies: preemtive resolution of banks´ financial distress. Such "distress mergers" can be a significant motivation for mergers because they can foster reorganizations, realize diversification gains, and avoid public attention. However, since none of these potential benefits comes without a cost, the overall assessment of distress mergers is unclear. We conduct an empirical analysis to provide evidence on consequences of distress mergers. The analysis is based on comprehensive data from Germany´s savings and cooperatives banks sectors over the period 1993 to 2001. During this period both sectors faced significant structural problems and superordinate institutions (associations) presumably have engaged in coordinated actions to manage distress mergers. The data comprise 3640 banks and 1484 mergers. Our results suggest that bank mergers as a means of preemtive distress resolution have moderate costs in terms of the economic impact on performance. We do find strong evidence consistent with diversification gains. Thus, distress mergers seem to have benefits without affecting systematic stability adversely.
Tests for the existence and the sign of the volatility risk premium are often based on expected option hedging errors. When the hedge is performed under the ideal conditions of continuous trading and correct model specification, the sign of the premium is the same as the sign of the mean hedging error for a large class of stochastic volatility option pricing models. We show, however, that the problems of discrete trading and model mis-specification, which are necessarily present in any empirical study, may cause the standard test to yield unreliable results.
The question whether the adoption of International Financial Reporting Standards (IFRS) will result in measurable economic benefits is of special policy relevance in particular given the European Union’s decision to require the application of IFRS by listed companies from 2005/2007. In this paper, I investigate the common con-jecture that internationally recognized high quality reporting standards (IAS/IFRS or US-GAAP) reduce the cost of capital of adopting firms (e.g. Levitt 1998; IASB 2002). Building on Leuz/Verrecchia (2000), I use a set of German firms which pre-adopted such standards before 2005, but investigate the potential economic benefits by analyzing their expected cost of equity capital utilizing and customizing avail-able implied estimation methods (e.g. Gebhardt/Lee/Swaminathan 2001, Easton/Taylor/Shroff/Sougiannis 2002, Easton 2004). Evidence from a sample of about 13,000 HGB, 4,500 IAS/IFRS and 3,000 US-GAAP firm-month observations in the period 1993-2002 generally fails to document lower expected cost of equity capital and therefore measurable economic benefits for firms applying IAS/IFRS or US-GAAP. Accordingly, I caution to state that reporting under internationally accepted standards, per se, lowers the cost of equity capital of adopting firms.
In this study, we develop a technique for estimating a firm’s expected cost of equity capital derived from analyst consensus forecasts and stock prices. Building on the work of Gebhardt/Lee/-Swaminathan (2001) and Easton/Taylor/Shroff/Sougiannis (2002), our approach allows daily estimation, using only publicly available information at that date. We then estimate the expected cost of equity capital at the market, industry and individual firm level using historical German data from 1989-2002 and examine firm characteristics which are systematically related to these estimates. Finally, we demonstrate the applicability of the concept in a contemporary case study for DaimlerChrysler and the European automobile industry.
Empirical evidence suggests that even those firms presumably most in need of monitoring-intensive financing (young, small, and innovative firms) have a multitude of bank lenders, where one may be special in the sense of relationship lending. However, theory does not tell us a lot about the economic rationale for relationship lending in the context of multiple bank financing. To fill this gap, we analyze the optimal debt structure in a model that allows for multiple but asymmetric bank financing. The optimal debt structure balances the risk of lender coordination failure from multiple lending and the bargaining power of a pivotal relationship bank. We show that firms with low expected cash-flows or low interim liquidation values of assets prefer asymmetric financing, while firms with high expected cash-flow or high interim liquidation values of assets tend to finance without a relationship bank.
We investigate the connection between corporate governance system configurations and the role of intermediaries in the respective systems from a informational perspective. Building on the economics of information we show that it is meaningful to distinguish between internalisation and externalisation as two fundamentally different ways of dealing with information in corporate governance systems. This lays the groundwork for a description of two types of corporate governance systems, i.e. insider control system and outsider control system, in which we focus on the distinctive role of intermediaries in the production and use of information. It will be argued that internalisation is the prevailing mode of information processing in insider control system while externalisation dominates in outsider control system. We also discuss shortly the interrelations between the prevailing corporate governance system and types of activities or industry structures supported.
Tractable hedging - an implementation of robust hedging strategies : [This Version: March 30, 2004]
(2004)
This paper provides a theoretical and numerical analysis of robust hedging strategies in diffusion–type models including stochastic volatility models. A robust hedging strategy avoids any losses as long as the realised volatility stays within a given interval. We focus on the effects of restricting the set of admissible strategies to tractable strategies which are defined as the sum over Gaussian strategies. Although a trivial Gaussian hedge is either not robust or prohibitively expensive, this is not the case for the cheapest tractable robust hedge which consists of two Gaussian hedges for one long and one short position in convex claims which have to be chosen optimally.
The main results obtained within the energy scan program at the CERN SPS are presented. The anomalies in energy dependence of hadron production indicate that the onset of deconfinement phase transition is located at about 30 A GeV. For the first time we seem to have clear evidence for the existence of a deconfined state of matter in nature. PACS numbers: 24.85.+p
A widely recognized paper by Colin Mayer (1988) has led to a profound revision of academic thinking about financing patterns of corporations in different countries. Using flow-of-funds data instead of balance sheet data, Mayer and others who followed his lead found that internal financing is the dominant mode of financing in all countries, that financing patterns do not differ very much between countries and that those differences which still seem to exist are not at all consistent with the common conviction that financial systems can be classified as being either bank-based or capital market-based. This leads to a puzzle insofar as it calls into question the empirical foundation of the widely held belief that there is a correspondence between the financing patterns of corporations on the one side, and the structure of the financial sector and the prevailing corporate governance system in a given country on the other side. The present paper addresses this puzzle on a methodological and an empirical basis. It starts by comparing and analyzing various ways of measuring financial structure and financing patterns and by demonstrating that the surprising empirical results found by studies that relied on net flows are due to a hidden assumption. It then derives an alternative method of measuring financing patterns, which also uses flow-of-funds data, but avoids the questionable assumption. This measurement concept is then applied to patterns of corporate financing in Germany, Japan and the United States. The empirical results, which use an estimation technique for determining gross flows of funds in those cases in which empirical data are not available, are very much in line with the commonly held belief prior to Mayer’s influential contribution and indicate that the financial systems of the three countries do indeed differ from one another in a substantial way, and moreover in a way which is largely in line with the general view of the differences between the financial systems of the countries covered in the present paper.
We present a detailed study of chemical freeze-out in nucleus-nucleus collisions at beam energies of 11.6, 30, 40, 80 and 158A GeV. By analyzing hadronic multiplicities within the statistical hadronization approach, we have studied the strangeness production as a function of centre of mass energy and of the parameters of the source. We have tested and compared different versions of the statistical model, with special emphasis on possible explanations of the observed strangeness hadronic phase space under-saturation. We show that, in this energy range, the use of hadron yields at midrapidity instead of in full phase space artificially enhances strangeness production and could lead to incorrect conclusions as far as the occurrence of full chemical equilibrium is concerned. In addition to the basic model with an extra strange quark non-equilibrium parameter, we have tested three more schemes: a two-component model superimposing hadrons coming out of single nucleon-nucleon interactions to those emerging from large fireballs at equilibrium, a model with local strangeness neutrality and a model with strange and light quark non-equilibrium parameters. The behaviour of the source parameters as a function of colliding system and collision energy is studied. The description of strangeness production entails a non-monotonic energy dependence of strangeness saturation parameter gamma_S with a maximum around 30A GeV. We also present predictions of the production rates of still unmeasured hadrons including the newly discovered Theta^+(1540) pentaquark baryon.
We suggest that the fluctuations of strange hadron multiplicity could be sensitive to the equation of state and microscopic structure of strongly interacting matter created at the early stage of high energy nucleus-nucleus collisions. They may serve as an important tool in the study of the deconfinement phase transition. We predict, within the statistical model of the early stage, that the ratio of properly filtered fluctuations of strange to non-strange hadron multiplicities should have a non-monotonic energy dependence with a minimum in the mixed phase region.
The data on mT spectra of K0S K+ and K- mesons produced in all inelastic p + p and p + pbar interactions in the energy range sqrt(s)NN=4.7-1800GeV are compiled and analyzed. The spectra are parameterized by a single exponential function, dN/(m_T*dm_T)=C exp(-m_T/T), and the inverse slope parameter T is the main object of study. The T parameter is found to be similar for K0S, K+ and K- mesons. It increases monotonically with collision energy from T~30MeV at sqrt(s)NN=4.7GeV to T~220MeV at sqrt(s)NN=1800GeV. The T parameter measured in p+p and p+pbar interactions is significantly lower than the corresponding parameter obtained for central Pb+Pb collisions at all studied energies. Also the shape of the energy dependence of T is different for central Pb+Pb collisions and p+p(pbar) interactions.
We propose a method to experimentally study the equation of state of strongly interacting matter created at the early stage of nucleus--nucleus collisions. The method exploits the relation between relative entropy and energy fluctuations and equation of state. As a measurable quantity, the ratio of properly filtered multiplicity to energy fluctuations is proposed. Within a statistical approach to the early stage of nucleus-nucleus collisions, the fluctuation ratio manifests a non--monotonic collision energy dependence with a maximum in the domain where the onset of deconfinement occurs.
Production of Lambda and Antilambda hyperons was measured in central Pb-Pb collisions at 40, 80, and 158 A GeV beam energy on a fixed target. Transverse mass spectra and rapidity distributions are given for all three energies. The Lambda/pi ratio at mid-rapidity and in full phase space shows a pronounced maximum between the highest AGS and 40 A GeV SPS energies, whereas the anti-Lambda}/pi ratio exhibits a monotonic increase. PACS numbers: 25.75.-q
Fluctuations of charged particle number are studied in the canonical ensemble. In the infinite volume limit the fluctuations in the canonical ensemble are different from the fluctuations in the grand canonical one. Thus, the well-known equivalence of both ensembles for the average quantities does not extend for the fluctuations. In view of a possible relevance of the results for the analysis of fluctuations in nuclear collisions at high energies, a role of the limited kinematical acceptance is studied.
Report from NA49
(2004)
The most recent data of NA49 on hadron production in nuclear collisions at CERN SPS energies are presented. Anomalies in the energy dependence of pion and kaon production in central Pb+Pb collisions are observed. They suggest that the onset of deconfinement is located at about 30 AGeV. Large multiplicity and transverse momentum fluctuations are measured for collisions of intermediate mass systems at 158 AGeV. The need for a new experimental programme at the CERN SPS is underlined.