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- The larvae of Orthocladiinae (Diptera: Chironomidae) of the Holarctic region : keys and diagnoses (1983)

- Jurassic accretionary complex of the Tamba terrane, southwest Japan, and its formative process (1993)

- A graph theoretical approach to the analysis, comparison, and enumeration of crystal structures (2008)
- As an alternative approach to lattices and space groups, this work explores graph theory as a means to model crystal structures. The approach uses quotient graphs and nets - the graph theoretical equivalent of cells and lattices - to represent crystal structures. After a short review of related work, new classes of cycles in nets are introduced and their ability to distinguish between non-isomorphic nets and their computational complexity are evaluated. Then, two methods to estimate a structure’s density from the corresponding net are proposed. The first uses coordination sequences to estimate the number of nodes in a sphere, whereas the second method determines the maximal volume of a unit cell. Based on the quotient graph only, methods are proposed to determine whether nets consist of islands, chains, planes, or penetrating, disconnected sub-nets. An algorithm for the enumeration of crystal structures is revised and extended to a search for structures possessing certain properties. Particular attention is given to the exclusion of redundant nets and those, which, by the nature of their connectivity, cannot correspond to a crystal structure. Nets with four four-coordinated nodes, corresponding to sp3 hybridised carbon polymorphs with four atoms per unit cell, are completely enumerated in order to demonstrate the approach. In order to render quotient graphs and nets independent from crystal structures, they are reintroduced in a purely graph-theoretical way. Based on this, the issue of iso- and automorphism of nets is reexamined. It is shown that the topology of a net (that is the bonds in a crystal) constrains severely the symmetry of the embedding (that is the crystal), and in the case of connected nets the space group except for the setting. Several examples are studied and conclusions on phases are drawn (pseudo-cubic FeS2 versus pyrite; α- versus β- quartz; marcasite- versus rutile-like phases). As the automorphisms of certain quotient graphs stipulate a translational symmetry higher than an arbitrary embedding of the corresponding net would show, they are examined in more detail and a method to reduce the size of such quotient graphs is proposed. Besides two instructional examples with 2-dimensional graphs, the halite, calcite, magnesite, barytocalcite, and a strontium feldspar structures are discussed. For some of the structures it is shown that the quotient graph which is equivalent to a centred cell is reduced to a quotient graph equivalent to the primitive cell. For the partially disordered strontium feldspar, it is shown that even if it could be annealed to an ordered structure, the unit cell would likely remain unchanged. For the calcite and barytocalcite structures it is shown that the equivalent nets are not isomorphic.

- Applications of the functional renormalization group to quantum liquids (2007)
- The topic of this thesis is the functional renormalization group. We discuss some approximations schemes. Thereafter we apply these approximations to study different fields of condensed matter physics. Generally we have to evaluate an infinite set of vertex functions describing the scattering of particles. These vertex functions get renormalized away from their bare values governed by an infinite hierarchy of flow equations. We cannot expect to actually solve these equations but have to apply a couple of approximations. The aim is to somehow separate relevant contributions from irrelevant ones. One possible scheme opens up if we rescale fields and vertices. Here "relevance" is used in a quantitative way to describe the scaling behaviour of vertices close to a fixed point of the RG. One disadvantage of describing the system in terms of infinitely many vertices is that the majority of these vertices we have to evaluate are not of interest to us. In most cases we are just looking for the self-energy or the two-particle effective interaction. However there might be contributions to the flow of these vertices that are generated by irrelevant vertices. We generally assume that we can express irrelevant vertices in terms of the relevant and marginal ones. Then in turn it should be possible to write the contributions of these irrelevant vertices to the flow of relevant and marginal ones in terms of relevant and marginal vertices as well. We show how this can be achieved by what we term the adiabatic approximation. We now consider weakly interacting bosons at the critical point of Bose-Einstein condensation. As the transition takes place at a finite temperature this temperature defines an effective ultraviolet cut-off. For the investigation of physical properties that depend on momenta smaller than this cut-off it is therefore sufficient to describe the system by a classical field theory. Our central topic here is the self-energy of the bosons and we are able to evaluate it with the full momentum dependence. For small momenta it approaches a scaling form and as the momentum is gradually increased we observe a crossover to the perturbative regime. As a test for the reliability of our expression for the selfenergy we investigate the interaction induced shift of the critical. Our results compare quite satisfactory to the best available estimates for this shift. For the anomalous dimension our approach predicts the correct order of magnitude however with a considerable error. As an improvement we include more vertices into our calculations. Here we observe that our fixed point estimates indeed approach the best known results but this convergence is quite weak. We turn toward systems of interacting fermions. The formulation of the functional renormalization group implicitly requires knowledge of the true Fermi surface of the full interacting system. In general however we can just calculate it a-posteriori from the self-energy. The requirement to flow into a fixed point can be translated into a fine-tuning of the frequency/momentum independent part r_0 of the rescaled 2-point function. We show how this bare value is related to the momentum dependent effective interaction along the complete trajectory of the RG. On the other hand r_0 expresses the difference between the bare and the true Fermi surface. Putting both equations together results into an exact selfconsistency equation for the Fermi surface. We apply our self-consistency equation above to tackle the problem of finding the true Fermi surface of interacting fermions in low dimensions. The most simple non-trivial model with an inhomogeneous Fermi surface is a system of two coupled metallic chains. The process of interband backward scattering leads to a smoothing of the Fermi surface. Of special interest is if the Fermi momenta of the two bands collapse into just one value. We propose the term confinement transition for this behaviour. We bosonize the interband backward scattering by means of a Hubbard-Stratonovich transformation and treat our system as a single channel problem. This bosonization together with the adiabatic approximation allows us to investigate the system even at strong coupling. Within a simple one-loop treatment our method predicts a confinement transition at strong coupling. However taken vertex renormalizations into account we observe that this confinement is destroyed by fluctuations beyond one-loop. Actually we observe how the confined phase can be stabilized by the inclusion of interband umklapp scattering. Thereafter we consider the physically more relevant case of a two-dimensional system of infinitely many coupled metallic chains. Here the Fermi surface consists of two disconnected weakly curved sheets. We are able to repeat the calculations we have performed for our toy model. Within a self-consistent 2-loop calculation indeed signs for a confinement transition at finite coupling strength emerge.

- Energy dependence of multiplicity fluctuations in heavy ion collisions at the CERN SPS (2008)
- In this work data of the NA49 experiment at CERN SPS on the energy dependence of multiplicity fluctuations in central Pb+Pb collisions at 20A, 30A, 40A, 80A and 158A GeV, as well as the system size dependence at 158A GeV, is analysed for positively, negatively and all charged hadrons. Furthermore the rapidity and transverse momentum dependence of multiplicity fluctuations are studied. The experimental results are compared to predictions of statistical hadron-gas and string-hadronic models. It is expected that multiplicity fluctuations are sensitive to the phase transition to quark-gluon-plasma (QGP) and to the critical point of strongly interacting matter. It is predicted that both the onset of deconfinement, the lowest energy where QGP is created, and the critical point are located in the SPS energy range. Furthermore, the predictions for the multiplicity fluctuations of statistical and string-hadronic models are different, the experimental data might allow to distinguish between them. The used measure of multiplicity fluctuations is the scaled variance omega, defined as the ratio of the variance and the mean of the multiplicity distribution. In the NA49 experiment the tracks of charged particles are detected in four large volume time projection chambers (TPCs). In order to remove possible detector effects a detailed study of event and track selection criteria is performed. Naively one would expect Poisson fluctuations in central heavy ion collisions. A suppression of fluctuations compared to a Poisson distribution is observed for positively and negatively charged hadrons at forward rapidity in Pb+Pb collisions. At midrapidity and for all charged hadrons the fluctuations are larger than the Poisson ones. The fluctuations seem to increase with decreasing system size. It is suggested that this is due to increased relative fluctuations in the number of participants. Furthermore, it was discovered that omega increases for decreasing rapidity and transverse momentum. A hadron-gas model predicts different values of omega for different statistical ensembles. In the grand-canonical ensemble, where all conservation laws are fulfilled only on the average, not on an event-by-event basis, the predicted fluctuations are the largest ones. In the canonical ensemble the charges, namely the electrical charge, the baryon number and the strangeness, are conserved for each event. The scaled variance in this ensemble is smaller than for the grand-canonical ensemble. In the micro-canonical ensemble not only the charges, but also the energy and the momentum are conserved in each event, the predicted $omega$ is the smallest one. The grand-canonical and canonical formulations of the hadron-gas model over-predict fluctuations in the forward acceptance. In contrast to the experimental data no dependence of omega on rapidity and transverse momentum is expected. For the micro-canonical formulation, which predicts small fluctuations in the total phase space, no quantitative calculation is available yet for the limited experimental acceptance. The increase of fluctuations for low rapidities and transverse momenta can be qualitatively understood in a micro-canonical ensemble as an effect of energy and momentum conservation. The string-hadronic model UrQMD significantly over-predicts the mean multiplicities but approximately reproduces the scaled variance of the multiplicity distributions at all measured collision energies, systems and phase-space intervals. String-hadronic models predict for Pb+Pb collisions a monotonous increase of omega with collision energy, similar to the observations for p+p interactions. This is in contrast to the predictions of the hadron-gas model, where omega shows no energy dependence at higher energies. At SPS energies the predictions of the string-hadronic and hadron-gas models are in the same order of magnitude, but at RHIC and LHC energies the difference in omega in the full phase space is much larger. Experimental data should be able to distinguish between them rather easily. Narrower than Poissonian (omega < 1) multiplicity fluctuations measured in the forward kinematic region (1<y(pi)<y_{beam}) can be related to the reduced fluctuations predicted for relativistic gases with imposed conservation laws. This general feature of relativistic gases may be preserved also for some non-equilibrium systems as modeled by the string-hadronic approaches. A quantitative estimate shows that the predicted maximum in fluctuations due to a first order phase transition from hadron-gas to QGP is smaller than the experimental errors of the present experiment and can therefore neither be confirmed nor disproved. No sign of increased fluctuations as expected for a freeze-out near the critical point of strongly interacting matter is observed.

- Investigation of TRPC channel-modulating progestins and proteins (2008)
- In the first part of this study, we have identified the two steroid hormones progesterone and norgestimate as novel TRPC channel blockers. Both substances blocked TRPC-mediated Ca2+ influx with micromolar activities in fluorometric measurements. TRPC channel inhibition did not seem to be a general steroid effect since another progestin, the norgestimate metabolite levonorgestrel, was not effective. Norgestimate was 4- to 5-fold more active on the TRPC3/6/7 subfamily compared to TRPC4/5, whereas progesterone was similarly potent. This selectivity of norgestimate was confirmed by patch clamp recordings. As norgestimate blocked channels directly gated by DAG with a fast kinetic, we assume the compound acts on the channel protein itself. This view was further substantiated by the lack of effects on IP3R-mediated Ca2+ release from the endoplasmic reticulum, which is activated in parallel with TRPCs by Gq/11-coupled receptor stimulation. Norgestimate did not only block ectopically expressed TRPC channels but also native, TRPC-mediated currents in rat aortic smooth muscle cells with similar activity. The usefulness of norgestimate as a tool compound for the investigation of physiological TRPC functions was tested in isolated vessel rings. Consistent with TRPC6 being an essential component of the alpha-1-adrenoceptor-activated cation channel, we demonstrated a direct vasorelaxant, endothelium-independent effect of norgestimate on rat aortic rings precontracted with phenylephrine. Thus, our results provide further experimental support for a role of TRPC6 in alpha-1-adrenergic vessel constriction. In the second part of this study, we screened a human aorta cDNA-library for novel TRPC4-interacting proteins with a modified yeast two-hybrid (Y2H) system in which the TRPC4-C-terminus was expressed as tetrameric bait protein, thereby mimicking the native channel conformation. Of the eleven interacting proteins found SESTD1 was chosen for further analyses since it contains a phospholipid-binding Sec14p-like domain and thus could be involved in regulation of TRPC channels by phospholipids. After the biochemical validation of the found interaction, the first spectrin domain of SESTD1 was then identified to interact with the CIRB domain of TRPC4 in directed Y2H tests. SESTD1 also co-immunoprecipitated with the closely related TRPC5 protein in which the SESTD1-binding domain is highly conserved. Independent of the CIRB site, co-immunoprecipitation with TRPC6 and the distantly related TRPM8 channel was observed indicating the existence of other sites in these channel proteins that mediate interaction with SESTD1. Analysis of SESTD1 gene expression in human tissues showed that its transcripts are ubiquitously expressed and tissues with significant coexpression with TRPC4 and -5 were identified. We have generated two polyclonal antisera directed against SESTD1 that consistently detected SESTD1 protein in brain, aorta, heart, and in smooth muscle and endothelial cells. The functional consequences of the found interaction were investigated by examination of the TRPC5-mediated Ca2+ influx in a clonal HM1 cell line stably expressing the channel. Since SESTD1 overexpression had no detectable effects on TRPC5-mediated Ca2+ influx, most likely due to expression of endogenous SESTD1, we knocked-down the native protein with specific siRNA. This procedure reduced TRPC5-mediated Ca2+ influx following receptor stimulation by 50%. Parallel biotinylation experiments did not reveal any differences in cell surface expressed TRPC5-protein, suggesting that reduction of TRPC5 activity resulted from a loss of a direct SESTD1 effect on the channel. In addition, in immunofluorescence experiments we observed that reduced SESTD1 protein levels resulted in a redistribution of the multifunctional protein ß-catenin from the plasma membrane to the cytosol. This result may point to an involvement of SESTD1 in formation and maintenance of adherens junctions. SESTD1 contains a phospholipid-binding Sec14p-like domain and we were the first to demonstrate its Ca2+-dependent binding to phosphatidic acid and all physiological phosphatidylinositol mono- and bisphosphates in vitro. The physiological function of this binding activity is not known at present, but it could play a role in regulation of associated TRPC channels. TRPC4 and -5 channels are activated by phospholipid hydrolysis and also bind phospholipids directly. The identification of SESTD1 as novel TRPC-interacting protein could thus be an important step forward in the investigation and better comprehension of the complex molecular mechanisms of TRP channel regulation by lipids.

- Yiddish Theatre Forum (2002)
- The Yiddish Theatre Forum (YTF), published under the auspices of Mendele, was founded in 2002 to foster greater interaction among scholars, artists, librarians, and lay people interested in the history of Yiddish theatre and drama. In addition to serving as a clearing house for queries about Yiddish theatre personnel, plays, and productions, the YTF publishes a variety of articles, reviews, and guides. So far these have included brief articles analyzing individual plays; guides to library and archival resources in the United States, Europe, and South Africa; and book reviews. Recent years have brought a number of important new studies of Yiddish theatre. New books and scholarly articles have examined Yiddish theatre and drama in the Americas, Eastern and Western Europe, and more distant hubs like Australia and South Africa. Such works have been undertaken by scholars based in many different countries, working in a variety of fields, and with a corresponding range of methodological approaches. The central purpose of the Yiddish Theatre Forum is to provide a place online where professional and lay students of Yiddish theatre can exchange ideas and information. Queries and other postings to the YTF can be sent directly to the Editor at yankl@albany.edu. Editorial Board Joel Berkowitz (University at Albany), Editor Leonard Prager (Haifa University), Senior Advisor Zachary Baker (Stanford University Libraries) Miroslawa Bułat (Jagiellonian University, Cracow) Avrom Greenbaum (Hebrew University, Jerusalem) Barbara Henry (University of Washington, Seattle) David Mazower (BBC / Independent Scholar) Nina Warnke (University of Texas at Austin) Seth Wolitz (University of Texas at Austin)

- The mendele review (1997)
- The Mendele Review is a literary supplement edited by Leonard Prager of Haifa University. It focuses on topics related to the Yiddish language and Yiddish literature.

- Writing against the odds : the south’s cultural and literary struggle against progress and modernity (2008)

- Elites and institutions : literature review (2006)
- Exploring elites and their relations to institutions can assist understanding the day-to-day realities of politics in Africa (Chabal and Daloz 1999, Amundsen 2001, Lindberg 2003). This review is a scoping exercise in what has been written on the subject in recent years. The main task of the review is to summarise current understandings of how elites work with and through political institutions in Africa. There is a huge literature in this subject area. We have tried to pick out a) that which is most pertinent and non-repetitive, and b) that which raises as many questions as it provides answers. On the whole we have focused on literature published in the last five to ten years and we have inclined towards the literature on Anglophone Africa. The review is presented as follows: Section 1 is an introduction to Africa’s recent political landscape and it introduces some of the major issues that appear in the literature. Section 2 provides some working definitions of elites, institutions and democratisation as three of the recurring themes in the review. Section 3 reviews literature broadly on democratisation in Africa and specifically on elections and elites. Section 4 examines how political parties have evolved over the last 15 years. Section 5 reviews the three branches of government and Section 6 briefly examines decentralisation and its relation to elites and politics. The remaining sections of the review move outside the more formal political structures to examine the media (Section 7), civil society (Section 8), women’s movements (Section 9), Trades unions (Section 10) and business associations (Section 11). The final Section 12 pulls out a number of gaps in the research that we have identified in the course of the review. Section 13 contains a complete bibliography of citations used in the review. It is crucial to remember that Africa’s experiences of democratisation are no more than 15 years old, and many scholars have cautioned that it is still very early to draw any definite conclusions (Amundsen 2001; Randall and Svasand 2002). Inhaltsverzeichnis: 1. Africa’s political landscape 3 * Diversity of ‘Africa’ 4 * Elections do not mean democracy 4 * Presidentialism 4 * Ethnicity 5 * Personal rule and patronage 5 2. Definitions 6 * Elites 6 * Political institutions 7 * Democratisation 8 3. Democratisation and elites 8 * Elections 9 * Elites and elections 13 4. Political parties 16 5. Branches of government 17 * The executive 17 * The legislature 18 * The Judiciary 20 6. Decentralisation 20 7. Media 21 * Radio 25 * Television 25 * Newspapers 25 * Internet 26 8. Civil society 26 9. Women’s movements 29 10. Trade unions 32 11. Business associations 34 12. Gaps in the research 36 13. Bibliography 38