Differential operators and Cherednik algebras

We establish a link between two geometric approaches to the representation theory of rational Cherednik algebras of type A: one based on a noncommutative Proj construction, used in [GS]; the other involving quantum hamiltonian reduction of an algebra of differential operators, used in [GG]. In the present paper, we combine these two points of view by showing that the process of hamiltonian reduction intertwines a naturally defined geometric twist functor on D-modules with the shift functor for the Cherednik algebra. That enables us to give a direct and relatively short proof of the key result, [GS, Theorem 1.4] without recourse to Haiman's deep results on the n! theorem. We also show that the characteristic cycles defined independently in these two approaches are equal, thereby confirming a conjecture from [GG].Comment: 37 p

Assessing Nuclear Proliferation by Using System Dynamics Modeling

The goal of this project is to understand the influence of social and cultural factors on nuclear proliferation. We identified factors that contribute to a country’s motivation to initiate a nuclear weapons program from political science literature, obtained relevant social and cultural information, and developed a system dynamics model. System dynamics is used to understand complex interactive systems with feedback. The modeling process began with the construction of a causal loop diagram, which contains the essential elements that account for nuclear proliferation and relationships between these elements. The relationships between the elements are represented by arrows that are labeled either positively or negatively to show their causal relationship. A positive sign represents a direct relationship and a minus sign represents an indirect or inverse relationship. The causal loop diagram is a mental model used to construct a stock and flow simulation model. This stock and flow model can be quantified with equations that capture the relationships amongst the elements of the system. Through system dynamics we were able to interpret the levels of variables which indicate how the system changes and gives us insight as to how each variable affects proliferation. The software used for our project was VenSim, by Ventana Systems, which enabled us to create a system dynamics model including our causal loop diagram and then place relevant variables into our stock and flow diagram. We are in the process of completing our stock and flow diagram, which will help us to gain a better understanding of the motivations for state–level nuclear proliferation. Proliferation assessment has an immense amount of factors to take into account. Through preliminary simulations of the model we demonstrated the impact of autocratic versus democratic governments on motivation to proliferate which is mediated by the differential levels of integration that results from economic trade. The model allows for expansion and lays the foundation for further investigation

Aerial Inventories of Waterfowl in Illinois and Estimation of Moist-soil Plant Seed Abundance for Waterfowl on Lands Managed by Illinois Department of Natural Resources

Grant/Contract No: W-43-R 53-54-55Reports on progress and results of inventories of waterfowl along the Illinois and central Mississippi rivers during fall and winter and estimation of moist-soil plant seed abundance for waterfowl on lands managed by Illinois Department of Natural ResourcesINHS Technical Report Prepared for U.S. Fish & Wildlife Service, Illinois Department of Natural Resource

Effects of <i>Eimeria stiedae</i> parasitism in the liver of rabbits on blood parameters and histoarchitecture of organs

The purpose of the research is to evaluate the parasitism effects on clinical parameters of laboratory animals.Materials and methods. The venous blood of 20 rabbits aged 1 year was taken to perform biochemical and general blood tests, for which purpose hematological analyzers were used. The animals were dissected using the Shor’s method. The topography of the organ complex was evaluated, and pathological material was collected and placed to 10% buffered formalin. For pathomorphological examination, liver, spleen, lung, and kidney samples were taken. To determine the histological pattern, paraffin-embedded samples on Thermo Scientific semi-automatic equipment were used. Histologic specimens were stained with hematoxylin and eosin. The histoarchitecture of the specimens was evaluated using an Axio A1.0 microscope, and photography was conducted with the AxioVision software.Results and discussion. The article presents the data of the general and biochemical blood tests of the blood from the rabbits intended to be used in the experiment. Further, the pathoanatomical picture of the liver was shown in animals infected with Eimeria spp., and the histological pattern was presented for parenchymal organs. We found that the main biochemical values that exceeded reference values were liver values, namely, aspartate aminotransferase and alanine aminotransferase. We also observed an increase in monocytes and granulocytes in the blood. Pathological and anatomical changes were only expressed in the liver, while no changes in the macro pattern were observed in other organs. Histological examination of parenchymal organs showed a significant pathology in the liver due to endogenous stages of oocysts occurred in its structure. Additionally, we observed a strong eosinophil response in the spleen and a high content of eosinophils in the pulmonary veins

Quantum Necking in Stressed Metallic Nanowires

When a macroscopic metallic wire is subject to tensile stress, it necks down smoothly as it elongates. We show that nanowires with radii comparable to the Fermi wavelength display remarkably different behavior. Using concepts from fluid dynamics, a PDE for nanowire shape evolution is derived from a semiclassical energy functional that includes electron-shell effects. A rich dynamics involving movement and interaction of kinks connecting locally stable radii is found, and a new class of universal equilibrium shapes is predicted.Comment: 4 pages, 3 postscript figures. New result on universal equilibrium shape

Minor and subthreshold depressive disorders in Alzheimer's disease: a systematic review and meta-analysis of prevalence studies

Background: Depressive symptoms are common in Alzheimer's disease (AD) and negatively impact patient well-being. The main aim of the present study was to establish summary estimates for the prevalence of minor depressive disorder (MinD) and subthreshold depression in AD and synthesise evidence on prognosis and management of these symptoms in order to inform clinical guidelines. / Methods: Systematic review and meta-analysis of cross-sectional and longitudinal studies of prevalence, prognosis, and treatments for minor and subthreshold depression in AD. We searched MEDLINE, Embase, PsycINFO and CINAHL. We included studies that reported prevalence of subthreshold depressive disorders and those reporting data on validity of diagnostic criteria, mechanisms, or randomised controlled clinical trials (RCTs) testing effectiveness of interventions. Estimates of prevalence were pooled using random-effects meta-analyses. Two authors screened articles and independently extracted data on study characteristics. / Results: We reviewed 5671 abstracts, retrieved 621 full text articles and included a total of 15 studies. Pooling data from 10 studies showed that prevalence for MinD in AD was 22.0% (95% CI 16.0 to 28.0). Prevalence for a clinical diagnosis of MinD (DSM-III-R and DSM-IV) was 26.0% (95% CI 20.0 to 32.0; 6 studies). People with MinD experienced higher levels of neuropsychiatric symptoms, functional and cognitive decline, although studies remain cross-sectional. Neither sertraline nor a carer intervention were effective in reducing symptoms. / Conclusion: This review finds that MinD is prevalent in people with a diagnosis of AD and requires clinical attention. Research is warranted to develop effective interventions to treat and prevent these symptoms

Dose-dependent impact of larval Ascaris suum on host body weight in the mouse model

Ascaris lumbricoides and Ascaris suum are important helminth parasites of humans and pigs, respectively. Although it is now well established that the presence of mature adult worms in the host intestine contributes to significant nutritional morbidity, the impact of larval migratory ascariasis is far less well understood. The development of a mouse model to explore susceptibility and resistance to larval ascariasis in the lungs provided an opportunity to observe the impact of larval migration on host growth during the course of infection. Changes in body weight were monitored in two strains of inbred mice, the susceptible C57BL/6j and the resistant CBA/Ca. Groups of mice received one of four doses: 100, 500, 1000 and 3000 fully embryonated A. suum ova. Infected mice underwent post-mortem on days 6, 7 and 8 post-infection. Control mice received a placebo dose of intubation medium and underwent post-mortem on day 7 post-infection. Mice were weighed pre-infection (day 0) and post-infection on the day of post-mortem. At post-mortem, the lungs of each mouse were removed for enumeration of Ascaris larval burdens by means of the modified Baermann method. Control mice of each strain showed an increase in weight from preinfection to post-infection day. Within the C57BL/6j strain, mice infected with higher doses of Ascaris eggs experienced a reduction in body weight; for those given 3000 eggs this was on all three post-mortem days, and for those given 1000, on days 7 and 8. For CBA/Ca mice, only mice receiving the 3000 dose demonstrated a reduction in body weight. These findings suggest that larval migratory ascariasis has a significant negative impact upon host growth and that this is related to infective dose and larval burden

Phosphoproteome profiling uncovers a key role for CDKs in TNF signaling

Tumor necrosis factor (TNF) has various effects on phosphorylation-mediated cellular signaling. Combining phosphoproteomics, subcellular localization analyses and kinase inhibitor assays, the authors provide systems level insights into TNF signaling and identify modulators of TNF-induced cell death. Tumor necrosis factor (TNF) is one of the few cytokines successfully targeted by therapies against inflammatory diseases. However, blocking this well studied and pleiotropic ligand can cause dramatic side-effects. Here, we reason that a systems-level proteomic analysis of TNF signaling could dissect its diverse functions and offer a base for developing more targeted therapies. Therefore, we combine phosphoproteomics time course experiments with subcellular localization and kinase inhibitor analysis to identify functional modules of protein phosphorylation. The majority of regulated phosphorylation events can be assigned to an upstream kinase by inhibiting master kinases. Spatial proteomics reveals phosphorylation-dependent translocations of hundreds of proteins upon TNF stimulation. Phosphoproteome analysis of TNF-induced apoptosis and necroptosis uncovers a key role for transcriptional cyclin-dependent kinase activity to promote cytokine production and prevent excessive cell death downstream of the TNF signaling receptor. This resource of TNF-induced pathways and sites can be explored at

The Order of Phase Transitions in Barrier Crossing

A spatially extended classical system with metastable states subject to weak spatiotemporal noise can exhibit a transition in its activation behavior when one or more external parameters are varied. Depending on the potential, the transition can be first or second-order, but there exists no systematic theory of the relation between the order of the transition and the shape of the potential barrier. In this paper, we address that question in detail for a general class of systems whose order parameter is describable by a classical field that can vary both in space and time, and whose zero-noise dynamics are governed by a smooth polynomial potential. We show that a quartic potential barrier can only have second-order transitions, confirming an earlier conjecture [1]. We then derive, through a combination of analytical and numerical arguments, both necessary conditions and sufficient conditions to have a first-order vs. a second-order transition in noise-induced activation behavior, for a large class of systems with smooth polynomial potentials of arbitrary order. We find in particular that the order of the transition is especially sensitive to the potential behavior near the top of the barrier.Comment: 8 pages, 6 figures with extended introduction and discussion; version accepted for publication by Phys. Rev.

Persistent currents in Moebius strips

Relation between the geometry of a two-dimensional sample and its equilibrium physical properties is exemplified here for a system of non-interacting electrons on a Moebius strip. Dispersion relation for a clean sample is derived and its persistent current under moderate disorder is elucidated, using statistical analysis pertinent to a single sample experiment. The flux periodicity is found to be distinct from that in a cylindrical sample, and the essential role of disorder in the ability to experimentally identify a Moebius strip is pointed out.Comment: 5 pages, 4 figure