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The taxonomy of the family Desmodoridae (Nematoda: Desmodorida) is partially revised based on morphology. The diagnoses of the Desmodoridae and the subfamilies Desmodorinae and Spiriniinae are emended to accommodate re-analyzed morphological features. Eight known species are redescribed and the implication of the new findings for the taxonomy of the group is discussed. Amphispira and Metadesmodora are confirmed as genera inquirendae. Alaimonema and Sigmophoranema, and their corresponding type species, are proposed as inquirendae due to poor descriptions of the type material. The other three species of Sigmophoranema are transferred to the genus Onyx because they bear the diagnostic features of this group: spear-like dorsal tooth and s-shape precloacal supplements. Echinodesmodora, Paradesmodora and Stygodesmodora are transferred to the Spiriniinae based on the absence of a head capsule and on the amphidial fovea being surrounded by cuticle striation. Paradesmodora toreutes is transferred to the genus Acanthopharyngoides as A. toreutes comb. nov. The genus Onepunema does not fit in the family Desmodoridae because of diorchic males; thus, it is regarded as taxon incertae sedis.
Lists of valid genera for the two subfamilies are provided. A dichotomic key for the identification of the 14 genera within the Spiriinae is provided.
Antigenic and 3D structural characterization of soluble X4 and hybrid X4-R5 HIV-1 Env trimers
(2014)
Background: HIV-1 is decorated with trimeric glycoprotein spikes that enable infection by engaging CD4 and a chemokine coreceptor, either CCR5 or CXCR4. The variable loop 3 (V3) of the HIV-1 envelope protein (Env) is the main determinant for coreceptor usage. The predominant CCR5 using (R5) HIV-1 Env has been intensively studied in function and structure, whereas the trimeric architecture of the less frequent, but more cytopathic CXCR4 using (X4) HIV-1 Env is largely unknown, as are the consequences of sequence changes in and near V3 on antigenicity and trimeric Env structure.
Results: Soluble trimeric gp140 Env constructs were used as immunogenic mimics of the native spikes to analyze their antigenic properties in the context of their overall 3D structure. We generated soluble, uncleaved, gp140 trimers from a prototypic T-cell line-adapted (TCLA) X4 HIV-1 strain (NL4-3) and a hybrid (NL4-3/ADA), in which the V3 spanning region was substituted with that from the primary R5 isolate ADA. Compared to an ADA (R5) gp140, the NL4-3 (X4) construct revealed an overall higher antibody accessibility, which was most pronounced for the CD4 binding site (CD4bs), but also observed for mAbs against CD4 induced (CD4i) epitopes and gp41 mAbs. V3 mAbs showed significant binding differences to the three constructs, which were refined by SPR analysis. Of interest, the NL4-3/ADA construct with the hybrid NL4-3/ADA CD4bs showed impaired CD4 and CD4bs mAb reactivity despite the presence of the essential elements of the CD4bs epitope. We obtained 3D reconstructions of the NL4-3 and the NL4-3/ADA gp140 trimers via electron microscopy and single particle analysis, which indicates that both constructs inherit a propeller-like architecture. The first 3D reconstruction of an Env construct from an X4 TCLA HIV-1 strain reveals an open conformation, in contrast to recently published more closed structures from R5 Env. Exchanging the X4 V3 spanning region for that of R5 ADA did not alter the open Env architecture as deduced from its very similar 3D reconstruction.
Conclusions: 3D EM analysis showed an apparent open trimer configuration of X4 NL4-3 gp140 that is not modified by exchanging the V3 spanning region for R5 ADA.
Cross-frequency coupling (CFC) has been proposed to coordinate neural dynamics across spatial and temporal scales. Despite its potential relevance for understanding healthy and pathological brain function, the standard CFC analysis and physiological interpretation come with fundamental problems. For example, apparent CFC can appear because of spectral correlations due to common non-stationarities that may arise in the total absence of interactions between neural frequency components. To provide a road map towards an improved mechanistic understanding of CFC, we organize the available and potential novel statistical/modeling approaches according to their biophysical interpretability. While we do not provide solutions for all the problems described, we provide a list of practical recommendations to avoid common errors and to enhance the interpretability of CFC analysis.
Touring Girls
(2014)
Touring Girls tells the story of Jacob Mbuy a young Cameroonian whose primary objective in life is having affairs with as many women as possible. He is obsessed with abusing young girls as well as instilling hopeless hope in adult women. His demise comes when he changes his world from the Christian to the Moslem world where he confronts a new type of women who behave strangely and cannot dance to his tunes. Protected by Islamic traditions and strict government laws, Jacob lands into a hell of unprecedented problems.
If we take Benjamin's definitions to their logical conclusion, then the monad and the reproduced copy are set unequivocally into binary opposition, as we, the masses capable and most needful of action, are implicitly denied the potential for liberation through aesthetic experience. This denial could not have been his long-term intention. When we take into account the breadth of his writings in response to Fascism, and we look at the artistic movements, Dada in particular, that Benjamin defines as 'politicizing art,' it seems as though we risk too narrow a reading of Benjamin's theories by assuming the aura can be, or must be, done away with. Rather, I would argue that this moment of auratic interaction is crucial to effectively politicizing art at all. Mechanically-produced art, in order to function politically, must allow its audience the space necessary to step back, awaken their 'Geistesgegenwart', and take action 'before' the present moment is finished and past. The elimination of aura - as per Benjamin’s own definitions of aura - neuters the interaction this awakening requires. While Benjamin provides the framework and asks the right questions, when determining what will allow his definitions to realize their aims most fully, I submit that he draws his line in the wrong place.
Trends in Nollywood: A Study of Selected Genres is a welcome addition to the growing body of works on the Nigerian cinema. It is part film history and part film theory and criticism. The history part traces the origin of the Nigerian cinema up to the present era of video productions. The work examines in detail, the contextual issues which have helped to define emergent trends within the industry.
Background: Hereditary angioedema (HAE) due to C1 inhibitor deficiency is a rare but serious and potentially life-threatening disease marked by spontaneous, recurrent attacks of swelling. The study objective was to characterize direct and indirect resource utilization associated with HAE from the patient perspective in Europe.
Methods: The study was conducted in Spain, Germany, and Denmark to assess the real-world experience of HAE via a cross-sectional survey of HAE patients, including direct and indirect resource utilization during and between attacks for patients and their caregivers over the past 6 months. A regression model examined predictors of medical resource utilization.
Results: Overall, 164 patients had an attack in the past 6 months and were included in the analysis. The most significant predictor of medical resource utilization was the severity of the last attack (OR 2.6; p < 0.001). Among patients who sought medical care during the last attack (23%), more than half utilized the emergency department. The last attack prevented patients from their normal activities an average of 4-12 hours. Patient and caregiver absenteeism increased with attack severity and frequency. Among patients who were working or in school (n = 120), 72 provided work/school absenteeism data, resulting in an estimated 20 days missing from work/school on average per year; 51% (n = 84) indicated that HAE has hindered their career/educational advancement.
Conclusion: HAE poses a considerable burden on patients and their families in terms of direct medical costs and indirect costs related to lost productivity. This burden is substantial at the time of attacks and in between attacks.
Feathers in Reverse
(2014)
Feathers in Reverse is the ideal gift for a loved one who is scared of poetry. It engages and immerses readers with the luring subtlety of a serpent. Themes treated include good and evil, heaven and earth, man and woman, birth and death, urbanism and rural life, wealth and poverty. As much as the poet highlights salient issues and conflicts in everyday life, he suggests answers to burning problems as well. A common thread runs through the over 300 poems feathered and featured in this collection. The notion of the 'feather' is cross-cultural. It reminds us of the feather used as a pen in ancient Europe and the 'red feather' that is stuck on the caps of African notables as a mark of distinction. Feathers in Reverse is a magic pudding to be sampled, shared and indulged.
We study self- and cross-excitation of shocks in the Eurozone sovereign CDS market. We adopt a multivariate setting with credit default intensities driven by mutually exciting jump processes, to capture the salient features observed in the data, in particular, the clustering of high default probabilities both in time (over days) and in space (across countries). The feedback between jump events and the intensity of these jumps is the key element of the model. We derive closed-form formulae for CDS prices, and estimate the model by matching theoretical prices to their empirical counterparts. We find evidence of self-excitation and asymmetric cross-excitation. Using impulse-response analysis, we assess the impact of shocks and a potential policy intervention not just on a single country under scrutiny but also, through the effect on cross-excitation risk which generates systemic sovereign risk, on other interconnected countries.
An extensive survey of the relevant literature of dry grassland communities described for the territory of Serbia allowed us to check the validity and legitimacy of the nomenclature of this vegetation. Nomenclature rules of the International Code of Phytosociological Nomenclature were strictly followed. The syntaxonomic affiliation of communities to higher syntaxa was assessed according to existing syntaxonomic schemes for Serbia and the position determined by the original source. Higher syntaxa followed the synsystem of the socalled “EuroVegChecklist”. We have highlighted problems and some disagreement with the existing classification of dry grassland communities in Europe. A total of 134 dry grassland communities have so far been registered for Serbia. This list of syntaxa may serve for further research of grassland vegetation and its appropriate positioning within a syntaxonomical scheme of Europe.
ND3, ND1 and 39kDa subunits are more exposed in the de-active form of bovine mitochondrial complex I
(2014)
An intriguing feature of mitochondrial complex I from several species is the so-called A/D transition, whereby the idle enzyme spontaneously converts from the active (A) form to the de-active (D) form. The A/D transition plays an important role in tissue response to the lack of oxygen and hypoxic deactivation of the enzyme is one of the key regulatory events that occur in mitochondria during ischaemia. We demonstrate for the first time that the A/D conformational change of complex I does not affect the macromolecular organisation of supercomplexes in vitro as revealed by two types of native electrophoresis. Cysteine 39 of the mitochondrially-encoded ND3 subunit is known to become exposed upon de-activation. Here we show that even if complex I is a constituent of the I+III2+IV (S1) supercomplex, cysteine 39 is accessible for chemical modification in only the D-form. Using lysine-specific fluorescent labelling and a DIGE-like approach we further identified two new subunits involved in structural rearrangements during the A/D transition: ND1 (MT-ND1) and 39kDa (NDUFA9). These results clearly show that structural rearrangements during de-activation of complex I include several subunits located at the junction between hydrophilic and hydrophobic domains, in the region of the quinone binding site. De-activation of mitochondrial complex I results in concerted structural rearrangement of membrane subunits which leads to the disruption of the sealed quinone chamber required for catalytic turnover.
Quarks and gluons are the building blocks of all hadronic matter, like protons and neutrons. Their interaction is described by Quantum Chromodynamics (QCD), a theory under test by large scale experiments like the Large Hadron Collider (LHC) at CERN and in the future at the Facility for Antiproton and Ion Research (FAIR) at GSI. However, perturbative methods can only be applied to QCD for high energies. Studies from first principles are possible via a discretization onto an Euclidean space-time grid. This discretization of QCD is called Lattice QCD (LQCD) and is the only ab-initio option outside of the high-energy regime. LQCD is extremely compute and memory intensive. In particular, it is by definition always bandwidth limited. Thus—despite the complexity of LQCD applications—it led to the development of several specialized compute platforms and influenced the development of others. However, in recent years General-Purpose computation on Graphics Processing Units (GPGPU) came up as a new means for parallel computing. Contrary to machines traditionally used for LQCD, graphics processing units (GPUs) are a massmarket product. This promises advantages in both the pace at which higher-performing hardware becomes available and its price. CL2QCD is an OpenCL based implementation of LQCD using Wilson fermions that was developed within this thesis. It operates on GPUs by all major vendors as well as on central processing units (CPUs). On the AMD Radeon HD 7970 it provides the fastest double-precision D= kernel for a single GPU, achieving 120GFLOPS. D=—the most compute intensive kernel in LQCD simulations—is commonly used to compare LQCD platforms. This performance is enabled by an in-depth analysis of optimization techniques for bandwidth-limited codes on GPUs. Further, analysis of the communication between GPU and CPU, as well as between multiple GPUs, enables high-performance Krylov space solvers and linear scaling to multiple GPUs within a single system. LQCD calculations require a sampling of the phase space. The hybrid Monte Carlo (HMC) algorithm performs this. For this task, a single AMD Radeon HD 7970 GPU provides four times the performance of two AMD Opteron 6220 running an optimized reference code. The same advantage is achieved in terms of energy-efficiency. In terms of normalized total cost of acquisition (TCA), GPU-based clusters match conventional large-scale LQCD systems. Contrary to those, however, they can be scaled up from a single node. Examples of large GPU-based systems are LOEWE-CSC and SANAM. On both, CL2QCD has already been used in production for LQCD studies.
Recent density functional theory (DFT) calculations for KFe2As2 have been shown to be insufficient to satisfactorily describe angle-resolved photoemission (ARPES) measurements as well as observed de Haas–van Alphen (dHvA) frequencies. In the present work, we extend DFT calculations based on the full-potential linear augmented plane-wave method by dynamical mean field theory (DFT+DMFT) to include correlation effects beyond the local density approximation. We present results for two sets of reported crystal structures. Our calculations indicate that KFe2As2 is a moderately correlated metal with a mass renormalization factor of the Fe $3{\rm d}$ orbitals between 1.6 and 2.7. Furthermore, the obtained shape and size of the Fermi surface are in good agreement with ARPES measurements and we observe some topological changes with respect to DFT calculations such as the opening of an inner hole cylinder at the Z point. As a result, our calculated dHvA frequencies differ greatly from existing DFT results and qualitatively agree with experimental data. On this basis, we argue that correlation effects are important to understand the -presently under debate- nature of the superconducting state in KFe2As2.
Previous research has documented strong peer effects in risk taking, but little is known about how such social influences affect market outcomes. The consequences of social interactions are hard to isolate in financial data, and theoretically it is not clear whether peer effects should increase or decrease risk sharing. We design an experimental asset market with multiple risky assets and study how exogenous variation in real-time information about the portfolios of peer group members affects aggregate and individual risk taking. We find that peer information ameliorates under-diversification that occurs in a market without such information. One reason is that peer information increases risk aversion and induces a concern for relative income position that may reduce or amplify risk taking, depending on whether the context highlights the most or least successful trader. Thus, contrary to conventional wisdom, we show that social interactions may help to reduce earnings volatility in financial markets, and we discuss implications for institutional design.
We investigate the relationship between anchoring and the emergence of bubbles in experimental asset markets. We show that setting a visual anchor at the fundamental value (FV) in the first period only is sufficient to eliminate or to significantly reduce bubbles in laboratory asset markets. If no FV-anchor is set, bubble-crash patterns emerge. Our results indicate that bubbles in laboratory environments are primarily sparked in the first period. If prices are initiated around the FV, they stay close to the FV over the entire trading horizon. Our insights can be related to initial public offerings and the interaction between prices set on pre-opening markets and subsequent intra-day price dynamics.
“WAR IS PEACE, FREEDOM IS SLAVERY, AND IGNORANCE IS STRENGTH”. The slogan from George Orwell’s “1984” dystopia appears to capture the state of Russia’s 2014 official discourse quite accurately. This has not gone unnoticed by public and academic spectators in and outside Russia: while Bild magazine is counting Putin’s lies in his recent ARD interview, a Zeit article declares Russia itself to be a post-modern “lie”...
This paper examines the effect of imperfect labor market competition on the efficiency of compensation schemes in a setting with moral hazard, private information and risk-averse agents. Two vertically differentiated firrms compete for agents by offering contracts with fixed and variable payments. Vertical differentiation between firms leads to endogenous, type-dependent exit options for agents. In contrast to screening models with perfect competition, we find that existence of equilibria does not depend on whether the least-cost separating allocation is interim efficient. Rather, vertical differentiation allows the inferior firm to offer (cross-)subsidizing fixed payments even above the interim efficient level. We further show that the efficiency of variable pay depends on the degree of competition for agents: For small degrees of competition, low-ability agents are under-incentivized and exert too little effort. For large degrees of competition, high-ability agents are over-incentivized and bear too much risk. For intermediate degrees of competition, however, contracts are second-best despite private information.
This paper studies the use of performance pricing (PP) provisions in debt contracts and compares accounting-based with rating-based pricing designs. We find that rating-based provisions are used by volatile-growth borrowers and allow for stronger spread increases over the credit period. Accounting-based provisions are employed by opaque-growth borrowers and stipulate stronger spread reductions. Further, a higher spread-increase potential in rating-based contracts lowers the spread at the loan’s inception and improves the borrower’s performance later on. In contrast, a higher spread-decrease potential in accounting-based contracts lowers the initial spread and raises the borrower’s leverage afterwards. The evidence indicates that rating-based contracts are indeed employed for different reasons than accounting-based contracts: the former to signal a borrower’s quality, the latter to mitigate investment inefficiencies.
Based on a non-rigorous formalism called the “cavity method”, physicists have made intriguing predictions on phase transitions in discrete structures. One of the most remarkable ones is that in problems such as random k-SAT or random graph k-coloring, very shortly before the threshold for the existence of solutions there occurs another phase transition called condensation [Krzakala et al., PNAS 2007]. The existence of this phase transition seems to be intimately related to the difficulty of proving precise results on, e. g., the k-colorability threshold as well as to the performance of message passing algorithms. In random graph k-coloring, there is a precise conjecture as to the location of the condensation phase transition in terms of a distributional fixed point problem. In this paper we prove this conjecture, provided that k exceeds a certain constant k0.
The n_TOF facility operates at CERN with the aim of addressing the request of high accuracy nuclear data for advanced nuclear energy systems as well as for nuclear astrophysics. Thanks to the features of the neutron beam, important results have been obtained on neutron induced fission and capture cross sections of U, Pu and minor actinides. Recently the construction of another beam line has started; the new line will be complementary to the first one, allowing to further extend the experimental program foreseen for next measurement campaigns.
The study of neutron-induced reactions is of high relevance in a wide variety of fields, ranging from stellar nucleosynthesis and fundamental nuclear physics to applications of nuclear technology. In nuclear energy, high accuracy neutron data are needed for the development of Generation IV fast reactors and accelerator driven systems, these last aimed specifically at nuclear waste incineration, as well as for research on innovative fuel cycles. In this context, a high luminosity Neutron Time Of Flight facility, n_TOF, is operating at CERN since more than a decade, with the aim of providing new, high accuracy and high resolution neutron cross-sections. Thanks to the features of the neutron beam, a rich experimental program relevant to nuclear technology has been carried out so far. The program will be further expanded in the near future, thanks in particular to a new high-flux experimental area, now under construction.
The notion of ambivalence currently seems to be an invigorating figure with heuristic potential in political, social, and art theory. It refers to a plurality of possibilities, a paradoxical multiplicity, and a complex relationality. It foregrounds thinking in terms of indeterminacy and incommensurability, as well as in terms of the possible. Ambivalence has been deployed in positive ways, as offering political promise, while, at the same time, being regarded with suspicion.
Background: Risk stratification, detection of minimal residual disease (MRD), and implementation of novel therapeutic agents have improved outcome in acute lymphoblastic leukemia (ALL), but survival of adult patients with T-cell acute lymphoblastic leukemia (T-ALL) remains unsatisfactory. Thus, novel molecular insights and therapeutic approaches are urgently needed.
Methods: We studied the impact of B-cell CLL/lymphoma 11b (BCL11b), a key regulator in normal T-cell development, in T-ALL patients enrolled into the German Multicenter Acute Lymphoblastic Leukemia Study Group trials (GMALL; n = 169). The mutational status (exon 4) of BCL11b was analyzed by Sanger sequencing and mRNA expression levels were determined by quantitative real-time PCR. In addition gene expression profiles generated on the Human Genome U133 Plus 2.0 Array (affymetrix) were used to investigate BCL11b low and high expressing T-ALL patients.
Results: We demonstrate that BCL11b is aberrantly expressed in T-ALL and gene expression profiles reveal an association of low BCL11b expression with up-regulation of immature markers. T-ALL patients characterized by low BCL11b expression exhibit an adverse prognosis [5-year overall survival (OS): low 35% (n = 40) vs. high 53% (n = 129), P = 0.02]. Within the standard risk group of thymic T-ALL (n = 102), low BCL11b expression identified patients with an unexpected poor outcome compared to those with high expression (5-year OS: 20%, n = 18 versus 62%, n = 84, P < 0.01). In addition, sequencing of exon 4 revealed a high mutation rate (14%) of BCL11b.
Conclusions: In summary, our data of a large adult T-ALL patient cohort show that low BCL11b expression was associated with poor prognosis; particularly in the standard risk group of thymic T-ALL. These findings can be utilized for improved risk prediction in a significant proportion of adult T-ALL patients, which carry a high risk of standard therapy failure despite a favorable immunophenotype.
5-Lipoxygenase (5LO) is a key enzyme in biosynthesis of leukotrienes (LTs), lipid mediators of inflammation. To study the roles of the 5LO accessory proteins coactosin-like protein (CLP) and 5LO-activating protein (FLAP), we knocked down these proteins in human monocytic cells. Our results show that expression of CLP was required for full cellular 5LO activity when cells were activated with Ca2+ ionophore, as well as with a physiological stimulus (lipopolysaccharide followed by N-formylmethionyl-leucyl-phenylalanine). During LT biosynthesis in stimulated cells, 5LO typically translocates to the nuclear membrane. This redistribution, from cytosolic to perinuclear, was clearly compromised in both CLP- and FLAP-deficient cells. Our results suggest that the CLP–5LO interaction may be a target for reduced LT production.
We examined substrate-induced conformational changes in MjNhaP1, an archaeal electroneutral Na+/H+-antiporter resembling the human antiporter NHE1, by electron crystallography of 2D crystals in a range of physiological pH and Na+ conditions. In the absence of sodium, changes in pH had no major effect. By contrast, changes in Na+ concentration caused a marked conformational change that was largely pH-independent. Crystallographically determined, apparent dissociation constants indicated ∼10-fold stronger Na+ binding at pH 8 than at pH 4, consistent with substrate competition for a common ion-binding site. Projection difference maps indicated helix movements by about 2 Å in the 6-helix bundle region of MjNhaP1 that is thought to contain the ion translocation site. We propose that these movements convert the antiporter from the proton-bound, outward-open state to the Na+-bound, inward-open state. Oscillation between the two states would result in rapid Na+/H+ antiport.
The forest, savanna, and grassland biomes, and the transitions between them, are expected to undergo major changes in the future, due to global climate change. Dynamic Global Vegetation Models (DGVMs) are very useful to understand vegetation dynamics under present climate, and to predict its changes under future conditions. However, several DGVMs display high uncertainty in predicting vegetation in tropical areas. Here we perform a comparative analysis of three different DGVMs (JSBACH, LPJ-GUESS-SPITFIRE and aDGVM) with regard to their representation of the ecological mechanisms and feedbacks that determine the forest, savanna and grassland biomes, in an attempt to bridge the knowledge gap between ecology and global modelling. Model outcomes, obtained including different mechanisms, are compared to observed tree cover along a mean annual precipitation gradient in Africa. Through these comparisons, and by drawing on the large number of recent studies that have delivered new insights into the ecology of tropical ecosystems in general, and of savannas in particular, we identify two main mechanisms that need an improved representation in the DGVMs. The first mechanism includes water limitation to tree growth, and tree-grass competition for water, which are key factors in determining savanna presence in arid and semi-arid areas. The second is a grass-fire feedback, which maintains both forest and savanna occurrences in mesic areas. Grasses constitute the majority of the fuel load, and at the same time benefit from the openness of the landscape after fires, since they recover faster than trees. Additionally, these two mechanisms are better represented when the models also include tree life stages (adults and seedlings), and distinguish between fire-prone and shade-tolerant savanna trees, and fire-resistant and shade-intolerant forest trees. Including these basic elements could improve the predictive ability of the DGVMs, not only under current climate conditions but also and especially under future scenarios.
Futures markets are a potentially valuable source of information about market expectations. Exploiting this information has proved difficult in practice, because the presence of a time-varying risk premium often renders the futures price a poor measure of the market expectation of the price of the underlying asset. Even though the expectation in principle may be recovered by adjusting the futures price by the estimated risk premium, a common problem in applied work is that there are as many measures of market expectations as there are estimates of the risk premium. We propose a general solution to this problem that allows us to uniquely pin down the best possible estimate of the market expectation for any set of risk premium estimates. We illustrate this approach by solving the long-standing problem of how to recover the market expectation of the price of crude oil. We provide a new measure of oil price expectations that is considerably more accurate than the alternatives and more economically plausible. We discuss implications of our analysis for the estimation of economic models of energy-intensive durables, for the debate on speculation in oil markets, and for oil price forecasting.
The goal of Perspectives on Student Affairs in South Africa is to generate interest in student affairs in South Africa. The papers contained herein are based on best practice, local experience and well-researched international and local theories. The papers in this book deal with matters pertaining to international and national trends in student affairs: academic development, access and retention, counselling, and material support for students coming from disadvantaged backgrounds. They are linked to national and international developments, as described in the first two papers. This publication will assist both young and experienced practitioners as they grow into their task of developing the students entrusted to them. All contributors are South Africans with a great deal of experience in student affairs, and all are committed to the advancement of student affairs in South Africa. The editors are former heads of student affairs portfolios at two leading South African universities.
This article reviews the most recent results concerning second harmonic generation (SHG) experiments of non-phase matchable and phase matchable powder samples at high pressures and explains the pressure dependence of the intensity of the SHG signal by correlating it to the ratio between the average coherence length and the average particle size. The examples discussed here include pressure-induced structural changes in quartz, ZnO, ice VII and KIO3. It is shown that the second harmonic generation technique is a unique tool for the detection of pressure-induced structural phase transitions. It is laboratory based and allows fast measurements. It is complementary to X-ray diffraction and provides additional information about the presence of an inversion center for unknown or controversially discussed structures at high pressure.
The African species Cheiracanthium furculatum Karsch, 1879 was recognised as being introduced to Germany and is re-described and illustrated in the present study. C. tenuipes Roewer, 1961 is recognised as a junior synonym of C. africanum Lessert, 1921 (new synonymy); both subspecies of C. strasseni Strand, 1915, namely C. strasseni strasseni Strand, 1915 and C. strasseni aharonii Strand, 1915, are recognised as junior synonyms of C. mildei L. Koch, 1864 (new synonymies). Photographic images of the copulatory organs of the types of C. cretense Roewer, 1928, recently synonymised with C. mildei, are provided and discussed in the course of intraspecific variation in C. mildei. The female holotype of C. rehobothense Strand, 1915 is re-described and illustrated. Relations of C. rehobothense to other Cheiracanthium species are discussed.
Glioblastoma multiforme (GBM) is a deadly primary brain malignancy. Glioblastoma stem cells (GSC), which have the ability to self-renew and differentiate into tumor lineages, are believed to cause tumor recurrence due to their resistance to current therapies. A subset of GSCs is marked by cell surface expression of CD133, a glycosylated pentaspan transmembrane protein. The study of CD133-expressing GSCs has been limited by the relative paucity of genetic tools that specifically target them. Here, we present CD133-LV, a lentiviral vector presenting a single chain antibody against CD133 on its envelope, as a vehicle for the selective transduction of CD133-expressing GSCs. We show that CD133-LV selectively transduces CD133+ human GSCs in dose-dependent manner and that transduced cells maintain their stem-like properties. The transduction efficiency of CD133-LV is reduced by an antibody that recognizes the same epitope on CD133 as the viral envelope and by shRNA-mediated knockdown of CD133. Conversely, the rate of transduction by CD133-LV is augmented by overexpression of CD133 in primary human GBM cultures. CD133-LV selectively transduces CD133-expressing cells in intracranial human GBM xenografts in NOD.SCID mice, but spares normal mouse brain tissue, neurons derived from human embryonic stem cells and primary human astrocytes. Our findings indicate that CD133-LV represents a novel tool for the selective genetic manipulation of CD133-expressing GSCs, and can be used to answer important questions about how these cells contribute to tumor biology and therapy resistance.
This Day
(2014)
Loss has left Ella Spinner alone to care for her husband, Bart, who suffers from clinical depression. Their days now echo the tides: any progress made, rolls back. Yet Ella keeps pushing against the monotony. Set in Mossel Bay, Ella?s day begins like any other. But on this day the minutes begin to crack allowing change to filter through. As we cheer on her tenacity, we?re left asking ourselves what motivates anyone to try again.
The growing role of IT in real estate asset management – the appraisal process as a master sample
(2014)
MTO1-deficient mouse model mirrors the human phenotype showing complex I defect and cardiomyopathy
(2014)
Recently, mutations in the mitochondrial translation optimization factor 1 gene (MTO1) were identified as causative in children with hypertrophic cardiomyopathy, lactic acidosis and respiratory chain defect. Here, we describe an MTO1-deficient mouse model generated by gene trap mutagenesis that mirrors the human phenotype remarkably well. As in patients, the most prominent signs and symptoms were cardiovascular and included bradycardia and cardiomyopathy. In addition, the mutant mice showed a marked worsening of arrhythmias during induction and reversal of anaesthesia. The detailed morphological and biochemical workup of murine hearts indicated that the myocardial damage was due to complex I deficiency and mitochondrial dysfunction. In contrast, neurological examination was largely normal in Mto1-deficient mice. A translational consequence of this mouse model may be to caution against anaesthesia-related cardiac arrhythmias which may be fatal in patients.
The present work deals with the integration of variable renewable energy sources, wind and solar energy into the European and US power grid. In contrast to other networks, such as the gas supply mains, the electricity network is practically not able to store energy. Generation and consumption therefore always have tobe balanced. Currently, the load curve is viewed as a rigid boundary condition, which must be followed by the generation system. The basic idea of the approach followed here is that weather-dependent generation causes a shift of focus of the electricity supply. At high shares of wind and solar generation, the role of the rigid boundary condition falls to the residual load, that is, the remaining load after subtraction of renewable generation. The goal is to include the weather dependence as well as the load curve in the design of the future electricity supply.
After a brief introduction, the present work first turns to the underlying weather-, generation and load data, which form the starting point of the analysis. In addition, some basic concepts of energy economics are discussed, which are needed in the following.
In the main part of the thesis, several algorithms are developed to determine the load flow in a network with a high share of wind and solar energy and to determine the backup supply needed at the same time. Minimization of the energy needed from controllable power plants, the capacity variable power plants, and the capacity of storing serve as guiding principles. In addition, the optimization problem of grid extensions is considered. It is shown that it can be formulated as a convex optimization problem. It turns out that with an optimized, international transmission network which is about four times the currently available transmission capacity, much of the potential savings in backup energy (about 40%) in Europe can be reached. In contrast, a twelvefold increase the transmission capacity would be necessary for a complete implementation of all possible savings in dispatchable power plants.
The reduction of the dispatchable generation capacity and storage capacity, however, presents a greater challenge. Due to correlations in the generation of time series of individual countries, it may be reduced only with difficulty, and by only about 30%.
In the following, the influence of the relative share of wind and solar energy is illuminated and examined the interplay with the line capacitance. A stronger transmission network tends to lead to a higher proportion of wind energy being better integrated. With increasing line capacity, the optimal mix in Europe therefore shifts from about 70% to 80% wind. Similar analyses are carried out for the US with comparable results.
In addition, the cost of the overall system can be reduced. It is interesting at this point that the advantages for the network integration may outweigh higher production costs of individual technologies, so that it is more favourable from the viewpoint of the entire system to use the more expensive technologies.
Finally, attention is given to the flexibility of the dispatchable power plants. Starting from a Fourier-like decomposition of the load curve as it was a few years ago, when hardly renewable generation capacity was present, capacities of different flexibility classes of dispatchable power plant are calculated. For this purpose, it is assumed that the power plant park is able to follow the load curve without significant surplusses or deficits. From this examination, it is derived what capacity must at least be available without having to resort to a detailed database of existing power plants.
Assuming a strong European cooperation, with a stronger international transmission network, the dispatchable power capacity can be significantly reduced while maintaining security of supply and generating relatively small surplusses in dispatchable power plants.
Background: Evaluation of automated attenuation-based tube potential selection and its impact on image quality and radiation dose in CT (computed tomography) examinations for cancer staging.
Methods: A total of 110 (59 men, 51 women) patients underwent chest-abdomen-pelvis CT examinations; 55 using a fixed tube potential of 120 kV/current of 210 Reference mAs (using CareDose4D), and 55 using automated attenuation-based tube potential selection (CAREkV) also using a current of 210 Reference mAs. This evaluation was performed as a single-centre, observer-blinded retrospective analysis. Image quality was assessed by two readers in consensus. Attenuation, image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured or calculated for objective image evaluation. For the evaluation of radiation exposure, dose-length-product (DLP) values were compared and Size-specific dose estimates (SSDE) values were calculated.
Results: Diagnostic image quality was obtained from all patients. The median DLP (703.5 mGy · cm, range 390–2203 mGy · cm) was 7.9% lower when using the algorithm compared with the standard 120 kV protocol (median 756 mGy · cm, range 345–2267 mGy · cm). A reduction in potential to 100 kV occurred in 32 cases; therefore, these patients received significantly lower radiation exposure compared with the 120 kV protocol.
Conclusion: Automated attenuation-based tube potential selection produces good diagnostic image quality in chest-abdomen-pelvis CT and reduces the patient’s overall radiation dose by 7.9% compared to the standard 120 kV protocol.
In this paper, we investigate how the introduction of complex, model-based capital regulation affected credit risk of financial institutions. Model-based regulation was meant to enhance the stability of the financial sector by making capital charges more sensitive to risk. Exploiting the staggered introduction of the model-based approach in Germany and the richness of our loan-level data set, we show that (1) internal risk estimates employed for regulatory purposes systematically underpredict actual default rates by 0.5 to 1 percentage points; (2) both default rates and loss rates are higher for loans that were originated under the model-based approach, while corresponding risk-weights are significantly lower; and (3) interest rates are higher for loans originated under the model-based approach, suggesting that banks were aware of the higher risk associated with these loans and priced them accordingly. Further, we document that large banks benefited from the reform as they experienced a reduction in capital charges and consequently expanded their lending at the expense of smaller banks that did not introduce the model-based approach. Counter to the stated objectives, the introduction of complex regulation adversely affected the credit risk of financial institutions. Overall, our results highlight the pitfalls of complex regulation and suggest that simpler rules may increase the efficacy of financial regulation.
In this paper, we investigate how the introduction of complex, model-based capital regulation affected credit risk of financial institutions. Model-based regulation was meant to enhance the stability of the financial sector by making capital charges more sensitive to risk. Exploiting the staggered introduction of the model-based approach in Germany and the richness of our loan-level data set, we show that (1) internal risk estimates employed for regulatory purposes systematically underpredict actual default rates by 0.5 to 1 percentage points; (2) both default rates and loss rates are higher for loans that were originated under the model-based approach, while corresponding risk-weights are significantly lower; and (3) interest rates are higher for loans originated under the model-based approach, suggesting that banks were aware of the higher risk associated with these loans and priced them accordingly. Further, we document that large banks benefited from the reform as they experienced a reduction in capital charges and consequently expanded their lending at the expense of smaller banks that did not introduce the model-based approach. Counter to the stated objectives, the introduction of complex regulation adversely affected the credit risk of financial institutions. Overall, our results highlight the pitfalls of complex regulation and suggest that simpler rules may increase the efficacy of financial regulation.
In this paper we investigate the implications of providing loan officers with a compensation structure that rewards loan volume and penalizes poor performance versus a fixed wage unrelated to performance. We study detailed transaction information for more than 45,000 loans issued by 240 loan officers of a large commercial bank in Europe. We examine the three main activities that loan officers perform: monitoring, originating, and screening. We find that when the performance of their portfolio deteriorates, loan officers increase their effort to monitor existing borrowers, reduce loan origination, and approve a higher fraction of loan applications. These loans, however, are of above-average quality. Consistent with the theoretical literature on multitasking in incomplete contracts, we show that loan officers neglect activities that are not directly rewarded under the contract, but are in the interest of the bank. In addition, while the response by loan officers constitutes a rational response to a time allocation problem, their reaction to incentives appears myopic in other dimensions.
Reading through the Charcoal Industry in Ethiopia : Production, Marketing, Consumption and Impact
(2014)
Studies in many African countries show that charcoal making is among the primary drivers of deforestation and subsequent land degradation. In the case of Ethiopia, charcoal is produced from state-owned (public) forests and woodlands. There is little regulatory intervention from the government side. Moreover, production is more traditional and the producers have little idea that charcoal can be produced efficiently with modern technologies. Although charcoal meets significant portion of urban households' energy needs in the country, and also support the livelihood of tens of thousands of rural households, it hardly attracted the attention of policy makers and development agents. A good majority of urban population who use charcoal on regular basis doesn't seem to know how charcoal is made, from where it comes, and its adverse environmental impacts. In cognizant of the potential environmental impact of charcoal production and marketing in the country, FSS commissioned this study with the objective to understand the environmental, social and economic implications of charcoal production, marketing and consumption in Ethiopia with aim to generate/increase awareness among the general public and incite a policy debate among concerned key stakeholders.
Acacia pendula, Weeping Myall, (family Fabaceae) is the most legislatively protected plant species in the New South Wales Hunter Valley. Under the NSW Threatened Species Conservation Act 1995 it is listed as an Endangered Population (in the Hunter Valley) and as a component of two Endangered Ecological Communities (one in the Hunter, one elsewhere in NSW); it is also listed as a Critically Endangered Ecological Community (in the Hunter Valley) on the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 and listed as threatened in three other eastern Australian States.
To ascertain the likely original distribution of stands of Acacia pendula in the Hunter Valley, this paper examines the writings of early Australian explorers, herbarium and database records, and the species habitat attributes across NSW. None of the journals examined, including those of botanist/explorer Allan Cunningham (who originally collected Acacia pendula from the Lachlan River in 1817), Thomas Mitchell or Ludwig Leichhardt, make note of the species for the Hunter Valley. Several explorers do, however, record Acacia pendula regularly (>100 times) across other parts of NSW, Queensland, and South Australia.
Historical herbarium and database records show a paucity of records from the Hunter prior to the year 2000, after which a 37-fold increase in observations since 1951 is apparent. For the first 128 years of botanical exploration (1823 to 1951), there are no validated collections or records of Acacia pendula from the Hunter Valley. The single exception is a specimen collected by Cunningham from 1825 (lodged at Kew, UK), purported to be from ‘Hunters River’, but which is morphologically different to other collections of Acacia pendula from that time. There is some uncertainty over the origins of this specimen.
Analysis of habitats supporting Acacia pendula in NSW outside of the Hunter show them to differ significantly in geological age, soil type, rainfall and elevation from those in the Hunter.
Collectively, these findings provide a strong circumstantial case that Acacia pendula was absent from the Hunter at the time of European settlement; this has important implications for the conservation and management of Hunter stands. Rather than being a threatened species in the Hunter Valley, it is postulated that Acacia pendula has been intentionally and/or accidentally introduced to the region, and may now be imposing a new and emerging threat to the endangered grassy woodlands and forests there. There is now an urgent need for genetic studies to clarify the origins of the current Hunter Valley stands, and to define the taxonomic limits of Acacia pendula and its close relatives.
The ( J, T ) = (1, 1) parity doublet in 20Ne at 11.26 MeV is a good candidate to study parity violation in nuclei. However, its energy splitting is known with insufficient accuracy for quantitative estimates of parity violating effects. To improve on this unsatisfactory situation, nuclear resonance fluorescence experiments using linearly and circularly polarized γ -ray beams were used to determine the energy difference of the parity doublet E = E(1−) − E(1+) = −3.2(±0.7)stat( +0.6 −1.2)sys keV and the ratio of their integrated cross sections I (+) s,0 /I (−) s,0 = 29(±3)stat( +14 −7 )sys. Shell-model calculations predict a parityviolating matrix element having a value in the range 0.46–0.83 eV for the parity doublet. The small energy difference of the parity doublet makes 20Ne an excellent candidate to study parity violation in nuclear excitations.
A concern for social regeneration stands as the factor that animates Soyinka's life-long involvement in social and political activism, leading to hid incarceration for two years during the civil war, and his having to flee into exile during the period of Sani Abacha's dictatorship. Soyinka expresses this same concern for social regeneration in his writings, using difference metaphors. The focus of this work lies in the exploration of the articulations of social regeneration in the works of Wole Soyinka. The first past focuses on the dramatic works, and the argument of the author is that the metaphor adopted by Africa's foremost playwright in articulating his vision of social regeneration is that of ritual. Attention shifts in part two to Soyinka's two novels; and here, Bello goes to the roots of Yoruba metaphysics to fetch a metaphor which describes a creature with contradictory personality; which at once is committed to the regeneration of the social order while at the same time retaining a vindictive, vengeful nature.
Escherichia coli α-hemolysin (HlyA) is a pore-forming protein of 110 kDa belonging to the family of RTX toxins. A hydrophobic region between the amino acid residues 238 and 410 in the N-terminal half of HlyA has previously been suggested to form hydrophobic and/or amphipathic α-helices and has been shown to be important for hemolytic activity and pore formation in biological and artificial membranes. The structure of the HlyA transmembrane channel is, however, largely unknown. For further investigation of the channel structure, we deleted in HlyA different stretches of amino acids that could form amphipathic β-strands according to secondary structure predictions (residues 71–110, 158–167, 180–203, and 264–286). These deletions resulted in HlyA mutants with strongly reduced hemolytic activity. Lipid bilayer measurements demonstrated that HlyAΔ71–110 and HlyAΔ264–286 formed channels with much smaller single-channel conductance than wildtype HlyA, whereas their channel-forming activity was virtually as high as that of the wildtype toxin. HlyAΔ158–167 and HlyAΔ180–203 were unable to form defined channels in lipid bilayers. Calculations based on the single-channel data indicated that the channels generated by HlyAΔ71–110 and HlyAΔ264–286 had a smaller size (diameter about 1.4 to 1.8 nm) than wildtype HlyA channels (diameter about 2.0 to 2.6 nm), suggesting that in these mutants part of the channel-forming domain was removed. Osmotic protection experiments with erythrocytes confirmed that HlyA, HlyAΔ71–110, and HlyAΔ264–286 form defined transmembrane pores and suggested channel diameters that largely agreed with those estimated from the single-channel data. Taken together, these results suggest that the channel-forming domain of HlyA might contain β-strands, possibly in addition to α-helical structures.
Low interest rates are becoming a threat to the stability of the life insurance industry, especially in countries such as Germany, where products with relatively high guaranteed returns sold in the past still represent a prominent share of the total portfolio. This contribution aims to assess and quantify the effects of the current low interest rate phase on the balance sheet of a representative German life insurer, given the current asset allocation and the outstanding liabilities. To do so, we generate a stochastic term structure of interest rates as well as stock market returns to simulate investment returns of a stylized life insurance business portfolio in a multi-period setting. Based on empirically calibrated parameters, we can observe the evolution of the life insurers' balance sheet over time with a special focus on their solvency situation. To account for different scenarios and in order to check the robustness of our findings, we calibrate different capital market settings and different initial situations of capital endowment. Our results suggest that a prolonged period of low interest rates would markedly affect the solvency situation of life insurers, leading to relatively high cumulative probability of default for less capitalized companies.
The title solvated salt, C29H41N2+·Br-·2CH2Cl2 was obtained from the reaction of the Arduengo-type carbene 1,3-bis(2,6-diisopropylphenyl)-1,3-dihydro-4,5-dimethyl-2H-imidazol-2-ylidene with Si2Br6 in dichloromethane. The complete cation is generated by a crystallographic mirror plane and the dihedral angle between the five-membered ring and the benzene ring is 89.8 (6)°; the dihedral angle between the benzene rings is 40.7 (2)°. The anion also lies on the mirror plane and both dichloromethane molecules are disordered across the mirror plane over two equally occupied orientations. In the crystal, the cations are linked to the anions via C-H...Br hydrogen bonds.
Background: Birch pollen-allergic subjects produce polyclonal cross-reactive IgE antibodies that mediate pollen-associated food allergies. The major allergen Bet v 1 and its homologs in plant foods bind IgE in their native protein conformation. Information on location, number and clinical relevance of IgE epitopes is limited. We addressed the use of an allergen-related protein model to identify amino acids critical for IgE binding of PR-10 allergens.
Method: Norcoclaurine synthase (NCS) from meadow rue is structurally homologous to Bet v 1 but does not bind Bet v 1-reactive IgE. NCS was used as the template for epitope grafting. NCS variants were tested with sera from 70 birch pollen allergic subjects and with monoclonal antibody BV16 reported to compete with IgE binding to Bet v 1.
Results: We generated an NCS variant (Δ29NCSN57/I58E/D60N/V63P/D68K) harboring an IgE epitope of Bet v 1. Bet v 1-type protein folding of the NCS variant was evaluated by 1H-15N-HSQC NMR spectroscopy. BV16 bound the NCS variant and 71% (50/70 sera) of our study population showed significant IgE binding. We observed IgE and BV16 cross-reactivity to the epitope presented by the NCS variant in a subgroup of Bet v 1-related allergens. Moreover BV16 blocked IgE binding to the NCS variant. Antibody cross-reactivity depended on a defined orientation of amino acids within the Bet v 1-type conformation.
Conclusion: Our system allows the evaluation of patient-specific epitope profiles and will facilitate both the identification of clinically relevant epitopes as biomarkers and the monitoring of therapeutic outcomes to improve diagnosis, prognosis, and therapy of allergies caused by PR-10 proteins.
This paper investigates the determinants of value and growth investing in a large administrative panel of Swedish residents over the 1999-2007 period. We document strong relationships between a household’s portfolio tilt and the household’s financial and demographic characteristics. Value investors have higher financial and real estate wealth, lower leverage, lower income risk, lower human capital, and are more likely to be female than the average growth investor. Households actively migrate to value stocks over the life-cycle and, at higher frequencies, dynamically offset the passive variations in the value tilt induced by market movements. We verify that these results are not driven by cohort effects, financial sophistication, biases toward popular or professionally close stocks, or unobserved heterogeneity in preferences. We relate these household-level results to some of the leading explanations of the value premium.
Hereditary angioedema (HAE) is a disease which is associated with random and often unpredictable attacks of painful swelling typically affecting the extremities, bowel mucosa, genitals, face and upper airway. Attacks are associated with significant functional impairment, decreased Health Related Quality of Life, and mortality in the case of laryngeal attacks. Caring for patients with HAE can be challenging due to the complexity of this disease. The care of patients with HAE in Canada is neither optimal nor uniform across the country. It lags behind other countries where there are more organized models for HAE management, and where additional therapeutic options are licensed and available for use. The objective of this guideline is to provide graded recommendations for the management of patients in Canada with HAE. This includes the treatment of attacks, short-term prophylaxis, long-term prophylaxis, and recommendations for self-administration, individualized therapy, quality of life, and comprehensive care. It is anticipated that by providing this guideline to caregivers, policy makers, patients and their advocates, that there will be an improved understanding of the current recommendations regarding management of HAE and the factors that need to be considered when choosing therapies and treatment plans for individual patients. The primary target users of this guideline are healthcare providers who are managing patients with HAE. Other healthcare providers who may use this guideline are emergency physicians, gastroenterologists, dentists and otolaryngologists, who will encounter patients with HAE and need to be aware of this condition. Hospital administrators, insurers and policy makers may also find this guideline helpful.
We propose a framework for estimating network-driven time-varying systemic risk contributions that is applicable to a high-dimensional financial system. Tail risk dependencies and contributions are estimated based on a penalized two-stage fixed-effects quantile approach, which explicitly links bank interconnectedness to systemic risk contributions. The framework is applied to a system of 51 large European banks and 17 sovereigns through the period 2006 to 2013, utilizing both equity and CDS prices. We provide new evidence on how banking sector fragmentation and sovereign-bank linkages evolved over the European sovereign debt crisis and how it is reflected in network statistics and systemic risk measures. Illustrating the usefulness of the framework as a monitoring tool, we provide indication for the fragmentation of the European financial system having peaked and that recovery has started.
We propose a new estimator for the spot covariance matrix of a multi-dimensional continuous semi-martingale log asset price process which is subject to noise and non-synchronous observations. The estimator is constructed based on a local average of block-wise parametric spectral covariance estimates. The latter originate from a local method of moments (LMM) which recently has been introduced by Bibinger et al. (2014). We extend the LMM estimator to allow for autocorrelated noise and propose a method to adaptively infer the autocorrelations from the data. We prove the consistency and asymptotic normality of the proposed spot covariance estimator. Based on extensive simulations we provide empirical guidance on the optimal implementation of the estimator and apply it to high-frequency data of a cross-section of NASDAQ blue chip stocks. Employing the estimator to estimate spot covariances, correlations and betas in normal but also extreme-event periods yields novel insights into intraday covariance and correlation dynamics. We show that intraday (co-)variations (i) follow underlying periodicity patterns, (ii) reveal substantial intraday variability associated with (co-)variation risk, (iii) are strongly serially correlated, and (iv) can increase strongly and nearly instantaneously if new information arrives.
Research in the field of Digital Humanities, also known as Humanities Computing, has seen a steady increase over the past years. Situated at the intersection of computing science and the humanities, present efforts focus on making resources such as texts, images, musical pieces and other semiotic artifacts digitally available, searchable and analysable. To this end, computational tools enabling textual search, visual analytics, data mining, statistics and natural language processing are harnessed to support the humanities researcher. The processing of large data sets with appropriate software opens up novel and fruitful approaches to questions in the traditional humanities. This report summarizes the Dagstuhl seminar 14301 on “Computational Humanities - bridging the gap between Computer Science and Digital Humanities”.
1998 ACM Subject Classification I.2.7 Natural Language Processing, J.5 Arts and Humanities
Money is more than memory
(2014)
Impersonal exchange is the hallmark of an advanced society. One key institution for impersonal exchange is money, which economic theory considers just a primitive arrangement for monitoring past conduct in society. If so, then a public record of past actions — or memory — supersedes the function performed by money. This intriguing theoretical postulate remains untested. In an experiment, we show that the suggested functional equality between money and memory does not translate into an empirical equivalence. Monetary systems perform a richer set of functions than just revealing past behaviors, which proves to be crucial in promoting large-scale cooperation.
We examine the relationship between household wealth and self-control. Although self-control has been linked to consumption and financial behavior, its measurement remains an open issue. We employ a definition of self-control failure that follows literature in psychology, suggesting that three factors can render self-control defective: lack of planning, lack of monitoring, and lack of commitment to pre-set plans. Our measure combines those three ingredients and can be computed using a standard representative survey. We find that self-control failure is strongly associated with different household net wealth measures and with self-assessed financial distress.
Panel Sample Selection ModelsThe empirical evidence currently available in the literature regarding the effects of a country's IMF program participation on its output growth is rather inconclusive. In this paper we propose and estimate a panel data sample selection model featuring state dependence. As in this model the output growth effects of program participation can be conditional on the realization of a state variable (conditional pooling), our framework may reconcile previous empirical evidence based on models without state-dependent effects. We find that the effects of IMF program participation on output growth vary systematically with an index reflecting a country's institutional record, and that output growth effects of program participation are significantly positive only if the program participation is coupled with sufficient improvement of the institutional record.
BACKGROUND: Recent findings support the idea that interleukin (IL)-22 serum levels are related to disease severity in end-stage liver disease. Existing scoring systems--Model for End-Stage Liver Disease (MELD), Survival Outcomes Following Liver Transplantation (SOFT) and Pre-allocation-SOFT (P-SOFT)--are well-established in appraising survival rates with or without liver transplantation. We tested the hypothesis that IL-22 serum levels at transplantation date correlate with survival and potentially have value as a predictive factor for survival.
MATERIAL AND METHODS: MELD, SOFT, and P-SOFT scores were calculated to estimate post-transplantation survival. Serum levels of IL-22, IL-6, IL-10, C-reactive protein (CRP), and procalcitonin (PCT) were collected prior to transplantation in 41 patients. Outcomes were assessed at 3 months, 1 year, and 3 years after transplantation.
RESULTS: IL-22 significantly correlated with MELD, P-SOFT, and SOFT scores (Rs 0.35, 0.63, 0.56 respectively, p<0.05) and with the discrimination in post-transplantation survival. IL-6 showed a heterogeneous pattern (Rs 0.40, 0.63, 0.57, respectively, p<0.05); CRP and PCT did not correlate. We therefore added IL-22 serum values to existing scoring systems in a generalized linear model (GLM), resulting in a significantly improved outcome prediction in 58% of the cases for both the P-SOFT (p<0.01) and SOFT scores (p<0.001).
CONCLUSIONS: Further studies are needed to address the concept that IL-22 serum values at the time of transplantation provide valuable information about survival rates following orthotopic liver transplantation.
Eryphanis zolvizora (Hewitson, 1877) is a rare Andean endemic butterfly, described from Bolivia, which has been historically classified either as a unique species, or as part of a group of three allopatric species from Bolivia, Ecuador and Colombia. In this paper, the group is revised using more than 200 specimens housed in 35 European and North and South American public and private collections. For the first time, the presence of the group in Western Ecuador and Venezuela is confirmed, and important data on Peruvian populations are provided. In some populations, individual variations of genitalia are observed. Nevertheless, male genitalia allow the distinction of four geographical groups. Considering also habitus characters, eight taxa are distinguished and considered to be subspecies, of which five are new: Eryphanis zolvizora inca ssp. nov., Eryphanis zolvizora chachapoya ssp. nov., Eryphanis zolvizora casagrande ssp. nov., Eryphanis zolvizora reyi ssp. nov., and Eryphanis zolvizora isabelae ssp. nov. In the present state of knowledge, these taxa are allopatric, except for a possible geographic overlap in central Peru, where data are insufficient to prove sympatry. The “several subspecies vs. several species” dilemma is discussed, considering its impact for conservation action and policies.
Andreas Fahrmeir’s history of the first half of the "long nineteenth century" begins with a disdainful Arthur Young travelling through France at the beginning of 1790 and ends with London’s Great Exhibition of 1851. The contrasting fortunes of France and Great Britain exemplify the contrasting concepts of the title. While the former experienced at least eleven contested regime changes – 1789, 1792, 1793, 1794, 1799, 1814, 1815 (twice), 1830, 1848 and 1850 – the British political system endured, albeit modified by reforms. Moreover, revolutionary-Napoleonic France was responsible for numerous revolutions from above elsewhere, uprooting old regimes and creating satellite states right across the continent, from the Batavian Republic to the Grand Duchy of Warsaw. Old Europe was not restored in 1815. With the Holy Roman Empire gone for good, the Low Countries combined in a single kingdom, Poland expunged from the map once again and the Habsburg Empire much more of an Italian and Balkan power than in the past, quite a new order had emerged. The shallow roots of the new creations ensured their future fragility. ...
Silometopus ambiguus (O. Pickard-Cambridge, 1905) is a species occurring in coastal habitats from northeastern to western Europe. S. curtus (Simon, 1881), occurring in southern France and north-eastern Spain, was for a long time mixed up with S. ambiguus, even though corrections have been published very early and several times. This contribution summarizes publications on this topic, discusses doubtful records of both species and proposes corrections for the World Spider Catalog; and thus tries to avoid repetitions of the mistake in the future.
ALMOST 20% OF THE GERMAN POPULATION CURRENTLY HOLDS A CONSUMER LOAN. DESPITE ITS OBVIOUS IMPORTANCE FOR A PRIVATE HOUSEHOLD’S BALANCE SHEET, WE KNOW SURPRISINGLY LITTLE ABOUT IT. ONE PURPOSE OF THIS STUDY IS TO GIVE AN OVERVIEW OF THE GERMAN CONSUMER/INSTALLMENT LOAN MARKET. WE COMPARED FIVE WIDELY ACCEPTED DATA SOURCES AND FOUND DIFFERENCES IN THE LOAN PARTICIPATION RATE, EVEN ON AN AGGREGATED NATIONWIDE LEVEL. IN A SECOND STEP, WE TRY TO FIND REASONS FOR EXTRAORDINARY HIGH GROWTH RATES AMONG SENIORS’ DEBT PARTICIPATION RATES.
Sanctions placed upon airlines and other operators transporting persons without the required paperwork are called ‘carrier sanctions’. They constitute a key example of how border control mechanisms are currently being outsourced, privatized, delegated, and moved from the border itself to new physical locations. These practices can lead to a phenomenon referred to in this paper as ‘hidden coercion’. This paper argues that, while hidden coercion is commonplace in the reality of migration policy in most states, it is so far neglected in theoretical discussions of state coercion. Moreover, the discussion of carrier sanctions demonstrates that this neglect is problematic, since hidden coercion is not justifiable even within a framework that legitimizes state border coercion.
This paper makes a conceptual contribution to the effect of monetary policy on financial stability. We develop a microfounded network model with endogenous network formation to analyze the impact of central banks' monetary policy interventions on systemic risk. Banks choose their portfolio, including their borrowing and lending decisions on the interbank market, to maximize profit subject to regulatory constraints in an asset-liability framework. Systemic risk arises in the form of multiple bank defaults driven by common shock exposure on asset markets, direct contagion via the interbank market, and firesale spirals. The central bank injects or withdraws liquidity on the interbank markets to achieve its desired interest rate target. A tension arises between the beneficial effects of stabilized interest rates and increased loan volume and the detrimental effects of higher risk taking incentives. We find that central bank supply of liquidity quite generally increases systemic risk.
This paper makes a conceptual contribution to the effect of monetary policy on financial stability. We develop a microfounded network model with endogenous network formation to analyze the impact of central banks' monetary policy interventions on systemic risk. Banks choose their portfolio, including their borrowing and lending decisions on the interbank market, to maximize profit subject to regulatory constraints in an asset-liability framework. Systemic risk arises in the form of multiple bank defaults driven by common shock exposure on asset markets, direct contagion via the interbank market, and firesale spirals. The central bank injects or withdraws liquidity on the interbank markets to achieve its desired interest rate target. A tension arises between the beneficial effects of stabilized interest rates and increased loan volume and the detrimental effects of higher risk taking incentives. We find that central bank supply of liquidity quite generally increases systemic risk.
We review recent results on J/ψ production measured by the ALICE collaboration at the LHC. For pp collisions at √s = 7 TeV yields and spectra of inclusive and prompt J/ψ, as well as results on their polarization and the charged particle multiplicity dependence of yields are presented. Measurements of the nuclear modification factor RAA of inclusive J/ψ at mid-(|y| < 0.9) and forward-rapidities (2.5 < y < 4), covering the range to pt = 0, for centrality selected Pb-Pb collisions are discussed. Also, first results on the J/ψυ2 at forward-rapidities are shown.
Background: The current taxonomy of the African giraffe (Giraffa camelopardalis) is primarily based on pelage pattern and geographic distribution, and nine subspecies are currently recognized. Although genetic studies have been conducted, their resolution is low, mainly due to limited sampling. Detailed knowledge about the genetic variation and phylogeography of the South African giraffe (G. c. giraffa) and the Angolan giraffe (G. c. angolensis) is lacking. We investigate genetic variation among giraffe matrilines by increased sampling, with a focus on giraffe key areas in southern Africa.
Results: The 1,562 nucleotides long mitochondrial DNA dataset (cytochrome b and partial control region) comprises 138 parsimony informative sites among 161 giraffe individuals from eight populations. We additionally included two okapis as an outgroup. The analyses of the maternally inherited sequences reveal a deep divergence between northern and southern giraffe populations in Africa, and a general pattern of distinct matrilineal clades corresponding to their geographic distribution. Divergence time estimates among giraffe populations place the deepest splits at several hundred thousand years ago.
Conclusions: Our increased sampling in southern Africa suggests that the distribution ranges of the Angolan and South African giraffe need to be redefined. Knowledge about the phylogeography and genetic variation of these two maternal lineages is crucial for the development of appropriate management strategies.
Objective: The objective of this study was to describe and analyze the effects of depression on health care utilization and costs in a sample of multimorbid elderly patients.
Method: This cross-sectional analysis used data of a prospective cohort study, consisting of 1,050 randomly selected multimorbid primary care patients aged 65 to 85 years. Depression was defined as a score of six points or more on the Geriatric Depression Scale (GDS-15). Subjects passed a geriatric assessment, including a questionnaire for health care utilization. The impact of depression on health care costs was analyzed using multiple linear regression models. A societal perspective was adopted.
Results: Prevalence of depression was 10.7%. Mean total costs per six-month period were €8,144 (95% CI: €6,199-€10,090) in patients with depression as compared to €3,137 (95% CI: €2,735-€3,538; p<0.001) in patients without depression. The positive association between depression and total costs persisted after controlling for socio-economic variables, functional status and level of multimorbidity. In particular, multiple regression analyses showed a significant positive association between depression and pharmaceutical costs.
Conclusion: Among multimorbid elderly patients, depression was associated with significantly higher health care utilization and costs. The effect of depression on costs was even greater than reported by previous studies conducted in less morbid patients.
Families are central to the social and emotional development of youth, and most families engage in musical activities together, such as listening to music or talking about their favorite songs. However, empirical evidence of the positive effects of musical family rituals on social cohesion and emotional well-being is scarce. Furthermore, the role of culture in the shaping of musical family rituals and their psychological benefits has been neglected entirely. This paper investigates musical rituals in families and in peer groups (as an important secondary socialization context) in two traditional/collectivistic and two secular/individualistic cultures, and across two developmental stages (adolescence vs. young adulthood). Based on cross-sectional data from 760 young people in Kenya, the Philippines, New Zealand, and Germany, our study revealed that across cultures music listening in families and in peer groups contributes to family and peer cohesion, respectively. Furthermore, the direct contribution of music in peer groups on well-being appears across cultural contexts, whereas musical family rituals affect emotional well-being in more traditional/collectivistic contexts. Developmental analyses show that musical family rituals are consistently and strongly related to family cohesion across developmental stages, whereas musical rituals in peer groups appear more dependent on the developmental stage (in interaction with culture). Contributing to developmental as well as cross-cultural psychology, this research elucidated musical rituals and their positive effects on the emotional and social development of young people across cultures. The implications for future research and family interventions are discussed.
Resveratrol shows beneficial effects in inflammation-based diseases like cancer, cardiovascular and chronic inflammatory diseases. Therefore, the molecular mechanisms of the anti-inflammatory resveratrol effects deserve more attention. In human epithelial DLD-1 and monocytic Mono Mac 6 cells resveratrol decreased the expression of iNOS, IL-8 and TNF-α by reducing mRNA stability without inhibition of the promoter activity. Shown by pharmacological and siRNA-mediated inhibition, the observed effects are SIRT1-independent. Target-fishing and drug responsive target stability experiments showed selective binding of resveratrol to the RNA-binding protein KSRP, a central post-transcriptional regulator of pro-inflammatory gene expression. Knockdown of KSRP expression prevented resveratrol-induced mRNA destabilization in human and murine cells. Resveratrol did not change KSRP expression, but immunoprecipitation experiments indicated that resveratrol reduces the p38 MAPK-related inhibitory KSRP threonine phosphorylation, without blocking p38 MAPK activation or activity. Mutation of the p38 MAPK target site in KSRP blocked the resveratrol effect on pro-inflammatory gene expression. In addition, resveratrol incubation enhanced KSRP-exosome interaction, which is important for mRNA degradation. Finally, resveratrol incubation enhanced its intra-cellular binding to the IL-8, iNOS and TNF-α mRNA. Therefore, modulation of KSRP mRNA binding activity and, thereby, enhancement of mRNA degradation seems to be the common denominator of many anti-inflammatory effects of resveratrol.
The birth of a new nation is an exciting time. Mick Bond spent the years 1962-73 as a District Officer and a District Commissioner, actively participating in the demise of the colonial regime and then as a civil servant in independent Zambia. This detailed account of his life and work includes the daily routine of a colonial officer, his personal experiences of the 1964 Lumpa conflict and his involvement in the elections of 1962, 1964, and 1968.
The link between atmospheric radicals and newly formed particles at a spruce forest site in Germany
(2014)
It has been claimed for more than a century that atmospheric new particle formation is primarily influenced by the presence of sulfuric acid. However, the activation process of sulfuric acid related clusters into detectable particles is still an unresolved topic. In this study we focus on the PARADE campaign measurements conducted during August/September 2011 at Mt Kleiner Feldberg in central Germany. During this campaign a set of radicals, organic and inorganic compounds and oxidants and aerosol properties were measured or calculated. We compared a range of organic and inorganic nucleation theories, evaluating their ability to simulate measured particle formation rates at 3 nm in diameter (J3) for a variety of different conditions. Nucleation mechanisms involving only sulfuric acid tentatively captured the observed noon-time daily maximum in J3, but displayed an increasing difference to J3 measurements during the rest of the diurnal cycle. Including large organic radicals, i.e. organic peroxy radicals (RO2) deriving from monoterpenes and their oxidation products, in the nucleation mechanism improved the correlation between observed and simulated J3. This supports a recently proposed empirical relationship for new particle formation that has been used in global models. However, the best match between theory and measurements for the site of interest was found for an activation process based on large organic peroxy radicals and stabilised Criegee intermediates (sCI). This novel laboratory-derived algorithm simulated the daily pattern and intensity of J3 observed in the ambient data. In this algorithm organic derived radicals are involved in activation and growth and link the formation rate of smallest aerosol particles with OH during daytime and NO3 during night-time. Because the RO2 lifetime is controlled by HO2 and NO we conclude that peroxy radicals and NO seem to play an important role for ambient radical chemistry not only with respect to oxidation capacity but also for the activation process of new particle formation. This is supposed to have significant impact of atmospheric radical species on aerosol chemistry and should be taken into account when studying the impact of new particles in climate feedback cycles.
Saccharum spontaneum L. is an invasive grass that has spread extensively in disturbed areas throughout the Panama Canal watershed (PCW), where it has created a fire hazard and inhibited reforestation efforts. Currently physical removal of aboveground biomass is the primary means of controlling this weed, which is largely ineffective and does little to inhibit spread of the species. Little is known about reproduction of this species, although it is both rhizomatous and produces abundant seed. Here we report a series of studies looking at some of the basic reproductive mechanisms and strategies utilised by S. spontaneum to provide information to support development of better targeted management strategies. We found that seed produced between September and November was germinable both in the lab and in situ. Genetic diversity of mature stands was assessed using microsatellite markers and found to be high, even at small scales. Studies of vegetative reproduction showed that buds on stems that had been dried for up to six weeks were still capable of sprouting. Separate experiments showed that stem fragments could sprout when left on the surface or buried shallowly and that larger pieces sprouted more readily than smaller pieces. Collectively these results demonstrate that S. spontaneum in the PCW has the capability to produce many propagules that can successfully recruit and it is likely that seed dispersal drives the spread of the species. Timing of management actions to reduce flowering would significantly reduce the seed load into the environment and help to prevent spread to new sites. Similarly, where biomass is cut, cutting stems into smaller pieces will allow the stems to dry out and reduce the ability of buds to sprout. Additionally, attention should be paid to prevent accidental transport to new sites on machinery.
Does austerity pay off?
(2014)
Policy makers often implement austerity measures when the sustainability of public finances is in doubt and, hence, sovereign yield spreads are high. Is austerity successful in bringing about a reduction in yield spreads? We employ a new panel data set which contains sovereign yield spreads for 31 emerging and advanced economies and estimate the effects of cuts of government consumption on yield spreads and economic activity. The conditions under which austerity takes place are crucial. During times of fiscal stress, spreads rise in response to the spending cuts, at least in the short-run. In contrast, austerity pays off, if conditions are more benign.
Emotions-at-risk: an experimental investigation into emotions, option prices and risk perception
(2014)
This paper experimentally investigates how emotions are associated with option prices and risk perception. Using a binary lottery, we find evidence that the emotion ‘surprise’ plays a significant role in the negative correlation between lottery returns and estimates of the price of a put option. Our findings shed new light on various existing theories on emotions and affect. We find gratitude, admiration, and joy to be positively associated with risk perception, although the affect heuristic predicts a negative association. In contrast with the predictions of the appraisal tendency framework (ATF), we document a negative correlation between option price and surprise for lottery winners. Finally, the results show that the option price is not associated with risk perception as commonly used in psychology.
Examination of the type material of the forgotten species Liocranum ochraceum Simon, 1867 reveals this species has to be transferred to the genus Anagraphis comb. nov. and that Anagraphis pallida (Hadjissarantos, 1940) is its junior synonym (syn. nov.). Furthermore, the monotypic genus Macedoniella Drensky, 1935 is a junior synonym of Anagraphis and M. karamani a junior synonym of Anagraphis ochraceum (L. Koch, 1867) (syn. nov.).
Populations of Stegelleta are described from California, New Zealand and Senegal. An amphimictic population from California is identified as belonging to S. incisa and compared with type specimens from Utah and an amphimictic population from Italy. One population from New Zealand is close to S. incisa but considered to represent a new species, Stegelleta laterocornuta sp. nov. It is particularly characterised by a 379–512 μm long body in females and 365–476 μm in males; cuticle divided into 16 rows of blocks at midbody (excluding lateral field); lateral field with four incisures; three pairs of asymmetrical lips, U-shaped primary axils without guarding processes, each lip asymmetrically rectangular with a smooth margin, only lateral lips have slender acute tines; three labial probolae, bifurcated at half of their length; vulva without flap; spermatheca 17–31 μm long; postuterine sac 7–24 μm long; spicules 21.5–23.5 μm long. Other specimens from New Zealand are identified as belonging to S. tuarua. A parthenogenetic population from Senegal is identified as belonging to S. ophioglossa and compared with type specimens from Mongolia and records of several other populations of S. ophioglossa. The generic diagnosis is emended and a key to the species of Stegelleta is provided.
We discuss recent applications of the partonic perturbative QCD based cascade model BAMPS with focus on heavy-ion phenomenology in the hard and soft momentum range. First, the elliptic flow and suppression of charm and bottom quarks are studied at LHC energies. Thereafter, we compare in a detailed study the standard Gunion-Bertsch approximation of the matrix elements for inelastic processes to the exact results in leading order perturbative QCD. Since a disagreement is found, we propose an improved Gunion-Bertsch matrix element, which agrees with the exact result in all phase space regions.
The laser-driven acceleration of protons from thin foils irradiated by hollow high-intensity laser beams in the regime of target normal sheath acceleration is reported for the first time. The use of hollow beams aims at reducing the initial emission solid angle of the TNSA source, due to a flattening of the electron sheath at the target rear side. The experiments were conducted at the PHELIX laser facility at the GSI Helmholtzzentrum für Schwerionenforschung GmbH with laser intensities in the range from 10^18 to 10^20 W/cm^2. We observed an average reduction of the half opening angle by (3.07±0.42)° or (13.2±2)% when the targets have a thickness between 12 to 14 μm. In addition, the highest proton energies were achieved with the hollow laser beam in comparison to the typical Gaussian focal spot.
Tubulin-binding agents such as taxol, vincristine or vinblastine are well-established drugs in clinical treatment of metastatic cancer. However, because of their highly complex chemical structures, the synthesis and hence the supply issues are still quite challenging. Here we set on stage pretubulysin, a chemically accessible precursor of tubulysin that was identified as a potent microtubule-binding agent produced by myxobacteria. Although much simpler in chemical structure, pretubulysin abrogates proliferation and long-term survival as well as anchorage-independent growth, and also induces anoikis and apoptosis in invasive tumor cells equally potent to tubulysin. Moreover, pretubulysin posseses in vivo efficacy shown in a chicken chorioallantoic membrane (CAM) model with T24 bladder tumor cells, in a mouse xenograft model using MDA-MB-231 mammary cancer cells and finally in a model of lung metastasis induced by 4T1 mouse breast cancer cells. Pretubulysin induces cell death via the intrinsic apoptosis pathway by abrogating the expression of pivotal antiapoptotic proteins, namely Mcl-1 and Bcl-xL, and shows distinct chemosensitizing properties in combination with TRAIL in two- and three-dimensional cell culture models. Unraveling the underlying signaling pathways provides novel information: pretubulysin induces proteasomal degradation of Mcl-1 by activation of mitogen-activated protein kinase (especially JNK (c-Jun N-terminal kinase)) and phosphorylation of Mcl-1, which is then targeted by the SCF(Fbw7) E3 ubiquitin ligase complex for ubiquitination and degradation. In sum, we designate the microtubule-destabilizing compound pretubulysin as a highly promising novel agent for mono treatment and combinatory treatment of invasive cancer.
Bacteria communicate via small diffusible molecules to mediate group-coordinated behavior, a process designated as quorum sensing. The basic molecular quorum sensing system of Gram-negative bacteria consists of a LuxI-type autoinducer synthase producing acyl-homoserine lactones (AHLs) as signaling molecules, and a LuxR-type receptor detecting the AHLs to control expression of specific genes. However, many proteobacteria possess one or more unpaired LuxR-type receptors that lack a cognate LuxI-like synthase, referred to as LuxR solos. The enteric and insect pathogenic bacteria of the genus Photorhabdus harbor an extraordinarily high number of LuxR solos, more than any other known bacteria, and all lack a LuxI-like synthase. Here, we focus on the presence and the different types of LuxR solos in the three known Photorhabdus species using bioinformatics analyses. Generally, the N-terminal signal-binding domain (SBD) of LuxR-type receptors sensing AHLs have a motif of six conserved amino acids that is important for binding and specificity of the signaling molecule. However, this motif is altered in the majority of the Photorhabdus-specific LuxR solos, suggesting the use of other signaling molecules than AHLs. Furthermore, all Photorhabdus species contain at least one LuxR solo with an intact AHL-binding motif, which might allow the ability to sense AHLs of other bacteria. Moreover, all three species have high AHL-degrading activity caused by the presence of different AHL-lactonases and AHL-acylases, revealing a high quorum quenching activity against other bacteria. However, the majority of the other LuxR solos in Photorhabdus have a N-terminal so-called PAS4-domain instead of an AHL-binding domain, containing different amino acid motifs than the AHL-sensors, which potentially allows the recognition of a highly variable range of signaling molecules that can be sensed apart from AHLs. These PAS4-LuxR solos are proposed to be involved in host sensing, and therefore in inter-kingdom signaling. Overall, Photorhabdus species are perfect model organisms to study bacterial communication via LuxR solos and their role for a symbiotic and pathogenic life style.
We analyze the implications of the structure of a network for asset prices in a general equilibrium model. Networks are represented via self- and mutually exciting jump processes, and the representative agent has Epstein-Zin preferences. Our approach provides a exible and tractable unifying foundation for asset pricing in networks. The model endogenously generates results in accordance with, e.g., the robust-yetfragile feature of financial networks shown in Acemoglu, Ozdaglar, and Tahbaz-Salehi (2014) and the positive centrality premium documented in Ahern (2013). We also show that models with simpler preference assumptions cannot generate all these findings simultaneously.
There has been a considerable debate about whether disaster models can rationalize the equity premium puzzle. This is because empirically disasters are not single extreme events, but long-lasting periods in which moderate negative consumption growth realizations cluster. Our paper proposes a novel way to explain this stylized fact. By allowing for consumption drops that can spark an economic crisis, we introduce a new economic channel that combines long-run and short-run risk. First, we document that our model can match consumption data of several countries. Second, it generates a large equity risk premium even if consumption drops are of moderate size.
We study the equilibrium properties of strongly-interacting infinite parton-hadron matter, characterized by the transport coefficients such as shear and bulk viscosity and electric conductivity, and the non-equilibrium dynamics of heavy-ion collisions within the Parton-Hadron-String Dynamics (PHSD) transport approach, which incorporates explicit partonic degrees of freedom in terms of strongly interacting quasiparticles (quarks and gluons) in line with an equation of state from lattice QCD as well as the dynamical hadronization and hadronic collision dynamics in the final reaction phase. We discuss in particular the possible origin for the strong elliptic flow v2 of direct photons observed at RHIC energies.
Two new species and one subspecies of Pharnaciini, belonging to two different genera, are described from Vietnam: one species and subspecies of Phryganistria Stål, 1875 and one species of Phobaeticus Brunner von Wattenwyl, 1907. Two species currently attributed to the genus Ramulus Saussure, 1862, Ramulus magnus (Brunner von Wattenwyl, 1907) and R. chinensis (Brunner von Wattenwyl, 1907), are transferred to Baculonistria Hennemann & Conle, 2008 comb. nov. Phobaeticus longicornis Bi & Wang, 1998 and Phobaeticus yuexiensis Chen & He, 1993 represent the male and female of Baculonistria magnus (Brunner von Wattenwyl, 1907) syn. nov. A lectotype is designated for Baculonistria chinensis (Brunner von Wattenwyl, 1907). The genus Baculonistria now contains three species. Nearchus bachmaensis Ta & Hoang, 2004 is transferred to Phryganistria and the new combination Phryganistria bachmaensis (Ta & Hoang, 2004) comb. nov. is proposed. The species is redescribed and the authors’ attribution corrected, the egg is described and figured for the first time.
Phryganistria tamdaoensis sp. nov. is described and figured from both sexes and the egg. Females of P. tamdaoensis sp. nov. are easily recognised by the conspicuously enlarged lanceolate cerci, a character previously unknown in this tribe. The distribution range of Phryganistria heusii heusii (Hennemann & Conle, 1997) is extended to Tam Dao National Park. A new subspecies Phryganistria heusii yentuensis subsp. nov. is described from Tay Yen Tu Nature Reserve from adult males and females and the eggs. Males can easily be distinguished from the nominal subspecies by their colouration. This huge subspecies represents the second longest insect recorded to date. A key to the species of the genus Phryganistria is provided. Phobaeticus trui sp. nov. is described from central Vietnam. It is the first species of Phobaeticus recorded from Vietnam. Adults of both sexes are illustrated.
A third Supplement to the 1992 Catalog of the Scolytidae and Platypodidae (Coleoptera) of the World (Wood and Bright 1992) is presented. This Supplement updates the taxonomy, distribution, and biology pertaining to these families of Coleoptera from 2000 to the end of 2010. A few 2011 taxonomic references are included in order to make the nomenclature as current as possible. The format of this Supplement differs slightly from the format of the original 1992 Catalog and the two previous Supplements. Only references relating to general biology, systematics and distribution were selected to be included. Tribal arrangement follows the scheme established in the 1992 World Catalog, with additions. Each genus is listed alphabetically under the current tribe and the species are listed alphabetically under the current genus. Additional information on figures, distribution, hosts, and references relating to the above are given. The bibliography used with this Supplement lists 580 references, most published from 2000 to the end of 2010. New synonymy proposed: Phloeotribus carinatus Burgos and Equihua, 2003 (= Phloeotribus ebeneus Wood, 2007). New combinations proposed: Phloeosinus kinabaluensis Bright to Hyledius; Phloeosinus phyllocladus Bright to Hyledius.
An argument is made for the retention of the family status of the Scolytidae and Platypodidae as members of the superfamily Curculionoidea. A new subfamily and tribal arrangement is proposed: SCOLYTIDAE comprising 13 subfamilies, Hylesininae, with 12 tribes, Hyorrhynchinae, with one tribe; Scolytinae, with one tribe; Hexacolinae, with one tribe; Cylindrobrotinae, with one tribe; Scolytoplatypodinae, with one tribe; Cactopininae, with one tribe; Carphodicticinae, with one tribe; Micracidinae, with one tribe; Crypturginae, with one tribe; Ipinae, with six tribes; Cryphalinae, with one tribe and Corthylinae, with two tribes and PLATYPODIDAE comprising three subfamilies, Coptonotinae, with three tribes; Tesserocerinae, with two tribes and Platypodinae, with one tribe.
It is common practice to use a 30-year period to derive climatological values, as recommended by the World Meteorological Organization. However this convention relies on important assumptions, of which the validity can be examined by deriving the uncertainty inherent to using a limited time-period for deriving climatological values. In this study a new method, aiming at deriving this uncertainty, has been developed with an application to precipitation for a station in Europe (Westdorpe) and one in Africa (Gulu). The weather generator framework is used to produce synthetic daily precipitation time-series that can also be regarded as alternative climate realizations. The framework consists of an improved Markov model, which shows good performance in reproducing the 5-day precipitation variability. The sub-seasonal, seasonal and the inter-annual signals are introduced in the weather generator framework by including covariates. These covariates are derived from an empirical mode decomposition analysis with an improved stability and significance assessment. Introducing covariates was found to substantially improve the monthly precipitation variability for Gulu. From the weather generator, 1,000 synthetic time-series were produced. The divergence between these time-series demonstrates an uncertainty, inherent to using a 30-year period for mean precipitation, of 11 % for Westdorpe and 15 % for Gulu. The uncertainty for precipitation 10-year return levels was found to be 37 % for both sites.
The flourishing of literature and thought during the age of Goethe may have inspired German nationalism in the 1930s, but Walter Benjamin identified other values in the period worth defending. 'Deutsche Menschen' is a short collection of edited letters by well-known German authors which Benjamin published in 1936 under the pseudonym Detlef Holz in order to hide his Jewish identity. In his inscription to Scholem's copy of the book, Benjamin wrote, "May you, Gerhard, find a chamber in this ark - which I built when the Fascist flood started to rise - for the memories of your youth," and in his sister’s copy Benjamin wrote, "This ark, built after a Jewish model, for Dora - From Walter." This essay considers what Benjamin may have meant by those inscriptions. Looking beyond discussions of "German," "Jewish," and even "German-Jewish" identity, this essay explores Benjamin's descriptions of his letter collection, asking how he conceptualized and framed it at first and how it may have changed between 1931 and 1936. The categories of tradition and agency will be my focus, which I will develop in the context of Benjamin's other writings and his particular interests in quotation and materialism. &e formation and reception of 'Deutsche Menschen' reveal a complex, ambitious project that combines many of Benjamin's ideas and goals.
Conviviality in Bellville: An Ethnography of Space, Place, Mobility and Being in Urban South Africa
(2014)
This book provides insight into the experiences of mobility and migration in contemporary South Africa, contributing to a field of literature about multiculturalism and urban public space in globalizing cities. It takes into consideration the greater international political and local socio-economic factors that drive migration, relationships and conviviality, and how they are intertwined in the everyday narrative of 'insiders' and 'outsiders'. The Bellville central business district demonstrates the realities of interconnected local and global hierarchies of citizenship and belonging and how they emerge in a world of accelerated mobility. The book further demonstrates how the emergence of conviviality in everyday public life represents a critical field for contemplating contemporary notions of human rights, citizenship and belonging.
Background: Endometriosis is characterized by the presence of functional endometrial tissue outside of the uterine cavity. It affects 1 in 10 women of reproductive age. This chronic condition commonly leads to consequences such as pelvic pain, dysmenorrhea, infertility and an elevated risk of epithelial ovarian cancer. Despite the prevalence of endometriosis and its impact on women's lives, there are relatively few in vitro and in vivo models available for studying the complex disease biology, pathophysiology, and for use in the preclinical development of novel therapies. The goal of this study was to develop a novel three-dimensional (3D) cell culture model of ovarian endometriosis and to test whether it is more reflective of endometriosis biology than traditional two dimensional (2D) monolayer cultures.
Methods: A novel ovarian endometriosis epithelial cell line (EEC16) was isolated from a 34-year old female with severe endometriosis. After characterization of cells using in vitro assays, western blotting and RNA-sequencing, this cell line and a second, already well characterized endometriosis cell line, EEC12Z, were established as in vitro 3D spheroid models. We compared biological features of 3D spheroids to 2D cultures and human endometriosis lesions using immunohistochemistry and real-time semi-quantitative PCR.
Results: In comparison to normal ovarian epithelial cells, EEC16 displayed features of neoplastic transformation in in vitro assays. When cultured in 3D, EEC16 and EEC12Z showed differential expression of endometriosis-associated genes compared to 2D monolayer cultures, and more closely mimicked the molecular and histological features of human endometriosis lesions.
Conclusions: To our knowledge, this represents the first report of an in vitro spheroid model of endometriosis. 3D endometriosis models represent valuable experimental tools for studying EEC biology and the development of novel therapeutic approaches.
The exact pathophysiology of contrast-induced nephropathy (CIN) is not fully clarified, yet the osmotic characteristics of contrast media (CM) have been a significant focus in many investigations of CIN. Osmotic effects of CM specific to the kidney include transient decreases in blood flow, filtration fraction, and glomerular filtration rate. Potentially significant secondary effects include an osmotically induced diuresis with a concomitant dehydrating effect. Clinical experiences that have compared the occurrence of CIN between the various classes of CM based on osmolality have suggested a much less than anticipated advantage, if any, with a lower osmolality. Recent animal experiments actually suggest that induction of a mild osmotic diuresis in association with iso-osmolar agents tends to offset potentially deleterious renal effects of high viscosity-mediated intratubular CM stagnation.
Ribosome heterogeneity is of increasing biological significance and several examples have been described for multicellular and single cells organisms. In here we show for the first time a variation in ribose methylation within the 18S rRNA of Saccharomyces cerevisiae. Using RNA-cleaving DNAzymes, we could specifically demonstrate that a significant amount of S. cerevisiae ribosomes are not methylated at 2′-O-ribose of A100 residue in the 18S rRNA. Furthermore, using LC-UV-MS/MS of a respective 18S rRNA fragment, we could not only corroborate the partial methylation at A100, but could also quantify the methylated versus non-methylated A100 residue. Here, we exhibit that only 68% of A100 in the 18S rRNA of S.cerevisiae are methylated at 2′-O ribose sugar. Polysomes also contain a similar heterogeneity for methylated Am100, which shows that 40S ribosome subunits with and without Am100 participate in translation. Introduction of a multicopy plasmid containing the corresponding methylation guide snoRNA gene SNR51 led to an increased A100 methylation, suggesting the cellular snR51 level to limit the extent of this modification. Partial rRNA modification demonstrates a new level of ribosome heterogeneity in eukaryotic cells that might have substantial impact on regulation and fine-tuning of the translation process.
Focus on quantum efficiency
(2014)
Technologies which convert light into energy, and vice versa, rely on complex, microscopic transport processes in the condensed phase, which obey the laws of quantum mechanics, but hitherto lack systematic analysis and modeling. Given our much improved understanding of multicomponent, disordered, highly structured, open quantum systems, this ‘focus on’ collection collects cuttingedge research on theoretical and experimental aspects of quantum transport in truly complex systems as defined, e.g., by the macromolecular functional complexes at the heart of photosynthesis, by organic quantum wires, or even photovoltaic devices. To what extent microscopic quantum coherence effects can (be made to) impact on macroscopic transport behavior is an equally challenging and controversial question, and this "focus on" collection provides a setting for the present state of affairs, as well as for the "quantum opportunities" on the horizon.
In old and heavily weathered soils, the availability of P might be so small that the primary production of plants is limited. However, plants have evolved several mechanisms to actively take up P from the soil or mine it to overcome this limitation. These mechanisms involve the active uptake of P mediated by mycorrhiza, biotic de-occlusion through root clusters, and the biotic enhancement of weathering through root exudation. The objective of this paper is to investigate how and where these processes contribute to alleviate P limitation on primary productivity. To do so, we propose a process-based model accounting for the major processes of the carbon, water, and P cycles including chemical weathering at the global scale. Implementing P limitation on biomass synthesis allows the assessment of the efficiencies of biomass production across different ecosystems. We use simulation experiments to assess the relative importance of the different uptake mechanisms to alleviate P limitation on biomass production. We find that active P uptake is an essential mechanism for sustaining P availability on long timescales, whereas biotic de-occlusion might serve as a buffer on timescales shorter than 10 000 yr. Although active P uptake is essential for reducing P losses by leaching, humid lowland soils reach P limitation after around 100 000 yr of soil evolution. Given the generalized modelling framework, our model results compare reasonably with observed or independently estimated patterns and ranges of P concentrations in soils and vegetation. Furthermore, our simulations suggest that P limitation might be an important driver of biomass production efficiency (the fraction of the gross primary productivity used for biomass growth), and that vegetation on old soils has a smaller biomass production rate when P becomes limiting. With this study, we provide a theoretical basis for investigating the responses of terrestrial ecosystems to P availability linking geological and ecological timescales under different environmental settings.
Soil water potential is crucial to plant transpiration and thus to carbon cycling and biosphere–atmosphere interactions, yet it is difficult to measure in the field. Volumetric and gravimetric water contents are easy and cheap to measure in the field, but can be a poor proxy of plant-available water. Soil water content can be transformed to water potential using soil moisture retention curves. We provide empirically derived soil moisture retention curves for seven soil types in the Kruger National Park, South Africa. Site-specific curves produced excellent estimates of soil water potential from soil water content values. Curves from soils derived from the same geological substrate were similar, potentially allowing for the use of one curve for basalt soils and another for granite soils. It is anticipated that this dataset will help hydrologists and ecophysiologists understand water dynamics, carbon cycling and biosphere–atmosphere interactions under current and changing climatic conditions in the region.
Myelodysplastic syndromes (MDSs) represent clonal disorders mainly of the elderly that are characterized by ineffective hematopoiesis and an increased risk of transformation into acute myeloid leukemia. The pathogenesis of MDS is thought to evolve from accumulation and selection of specific genetic or epigenetic events. Emerging evidence indicates that MDS is not solely a hematopoietic disease but rather affects the entire bone marrow microenvironment, including bone metabolism. Many of these cells, in particular mesenchymal stem and progenitor cells (MSPCs) and osteoblasts, express a number of adhesion molecules and secreted factors that regulate blood regeneration throughout life by contributing to hematopoietic stem and progenitor cell (HSPC) maintenance, self-renewal and differentiation. Several endocrine factors, such as erythropoietin, parathyroid hormone and estrogens, as well as deranged iron metabolism modulate these processes. Thus, interactions between MSPC and HSPC contribute to the pathogenesis of MDS and associated pathologies. A detailed understanding of these mechanisms may help to define novel targets for diagnosis and possibly therapy. In this review, we will discuss the scientific rationale of "osteohematology" as an emerging research field in MDS and outline clinical implications.
Fast nuclei are ionizing radiation which can cause deleterious effects to irradiated cells. The modelling of the interactions of such ions with matter and the related effects are very important to physics, radiobiology, medicine and space science and technology. A powerful method to study the interactions of ionizing radiation with biological systems was developed in the field of microdosimetry. Microdosimetry spectra characterize the energy deposition to objects of cellular size, i.e., a few micrometers.
In the present thesis the interaction of ions with tissue-like media was investigated using the Monte Carlo model for Heavy-Ion Therapy (MCHIT) developed at the Frankfurt Institute for Advanced Studies. MCHIT is a Geant4-based application intended to benchmark the physical models of Geant4 and investigate the physical properties of therapeutic ion beams. We have implemented new features in MCHIT in order to calculate microdosimetric quantities characterizing the radiation fields of accelerated nucleons and nuclei. The results of our Monte Carlo simulations were compared with recent experimental microdosimetry data.
In addition to microdosimetry calculations with MCHIT, we also investigated the biological properties of ion beams, e.g. their relative biological effectiveness (RBE), by means of the modified Microdosimetric-Kinetic model (MKM). The MKM uses microdosimetry spectra in describing cell response to radiation. MCHIT+MKM allowed us to study the physical and biological properties of ion beams. The main results of the thesis are as follows:
MCHIT is able to describe the spatial distribution of the physical dose in tissue-like media and microdosimetry spectra for ions with energies relevant to space research and ion-beam cancer therapy; MCHIT+MKM predicts a reduction of the biological effectiveness of ions propagating in extended medium due to nuclear fragmentation reactions; We predicted favourable biological dose-depth profiles for monoenergetic helium and lithium beams similar to the one for carbon beam. Well-adjusted biological dose distributions for H-1, He-4, C-12 and O-16 with a very flat spread-out Bragg peak (SOBP) plateau were calculated with MCHIT+MKM; MCHIT+MKM predicts less damage to healthy tissues in the entrance channel for SOBP He-4 and C-12 beams compared to H-1 and O-16 ones. No definitive advantages for oxygen ions with respect to carbon were found.