Compaction of Rods: Relaxation and Ordering in Vibrated, Anisotropic Granular Material

We report on experiments to measure the temporal and spatial evolution of packing arrangements of anisotropic, cylindrical granular material, using high-resolution capacitive monitoring. In these experiments, the particle configurations start from an initially disordered, low-packing-fraction state and under vertical vibrations evolve to a dense, highly ordered, nematic state in which the long particle axes align with the vertical tube walls. We find that the orientational ordering process is reflected in a characteristic, steep rise in the local packing fraction. At any given height inside the packing, the ordering is initiated at the container walls and proceeds inward. We explore the evolution of the local as well as the height-averaged packing fraction as a function of vibration parameters and compare our results to relaxation experiments conducted on spherically shaped granular materials.Comment: 9 pages incl. 7 figure

Neutron Thermal Cross Sections, Westcott Factors, Resonance Integrals, Maxwellian Averaged Cross Sections and Astrophysical Reaction Rates Calculated from Major Evaluated Data Libraries

We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellian-averaged cross sections and astrophysical reaction rates for 843 ENDF materials using data from the major evaluated nuclear libraries and European activation file. Extensive analysis of newly-evaluated neutron reaction cross sections, neutron covariances, and improvements in data processing techniques motivated us to calculate nuclear industry and neutron physics quantities, produce s-process Maxwellian-averaged cross sections and astrophysical reaction rates, systematically calculate uncertainties, and provide additional insights on currently available neutron-induced reaction data. Nuclear reaction calculations are discussed and new results are presented.Comment: 145 pages, 15 figures, 19 table

Nation, region, and power in the Southern abject heterotopia

This dissertation is rooted in an inquiry into why images of the grotesque and abjection are not only intimately associated with the American South, but also why these images are so readily produced and embraced by its writers, politicians, and artists. Is the production of these images just a question of pandering to national audience for material profit, or is there a deeper strategy at foot to assert regional identity and influence the nation? This dissertation argues the latter and asserts that a central purpose of the Southern abject is to subvert the structures of the national body and propose alternatives. Because the idea of a national body is, in itself rooted in somatic language and imagery, it is useful to investigate the impacts of transgressions of national purity in terms psychological responses to violations of bodily integrity. To this end, I will deploy ideas of abjection rooted in the work of Julia Kristeva and Judith Butler to determine the ways in which these transgressions reveal the constructed nature of the national body, denaturalizing its form, and creating a space in which alternative bodies can be formed which can exert not only regional agency, but also a form of national control. In order to do this, this dissertation examines three different “topographies” of abjection that were disruptive to the hegemonic national body’s sense purity at the end of the 19th and beginning of the 20th centuries. First, the objective topography, a view of the national body from the point of view of types of aspects of identity and experience that are measurable and quantifiable. These include elements of the physical world like the body and the environment, as well as the experience of time. The second layer, the social topography, includes aspects of identity like race, class, and gender, which effect the immediate social view and experience of the subject. The third layer is the historical topography. This topography has less to do with the literal passage of time than the emergence of the emergence of an agreed upon an agreed upon narrative that defines the ideological progress of the nation. The reason that these three topographies were important at the end of the 19th and beginning of the 20th centuries is that they represented areas in which changes in technology, medicine, and social sciences gave a new categories and language through which the national body and its threats could be defined. This dissertation argues that a supposedly progressive liberal North needed an abject South in order to perform the continual struggle for a “more perfect union: As such, the South as abject heterotopia in which abjection could be contained was, and is, essential to the nations ideological progress towards an ever more democratic nation. This containment in a grotesque “problem region”, also gave the nation a way of struggling with issues of objective, social, and historical abjection, while not confronting these same issues in the rest of the country. Interestingly, for the South, there is also a power in this abject positioning, in that the intentional deployment of forms of abjection can disrupt the supposed coherence of a national body. This is a powerful rhetorical and ideological tool that allows for a space to develop in which the norms of the national body can be challenged as unnatural and unhelpful and alternative bodies can be developed. Abjection achieves this by making plane the boundaries of the national body and revealing its constructed nature, and, in doing so, denaturalizing it so that its overarching hegemonic power is compromised by its own incoherence. The question then, is way does the South have this power in ways that other regions of the country do not? In this dissertation, I argue that the South is uniquely positioned to accomplish this because of its role as national member and outsider. The South’s unique history of separation and reunion means that the region can be seen as both a part of the national body and separate from it. The region’s role as a constituent part of the national body at its founding meant that it provided much of the leadership as the country formed its ideological direction, along with its early political and social discourse. At the same time, the region violently resisted this same national identity, forcing the nation to defeat and ideologically “recolonize” the region. This double-positioning as both a part of the national body and as the container of an antithetical ideology that had to be purged through a form of violent emesis makes the region a kind of abject heterotopia. Using the work of progressive writers like Erskine Caldwell who uses the objective topography of abjection to call attention to the ongoing damage caused by immoral exploitation of mindless capitalistic myth, and Jean Toomer who uses the social topography of abjection to disrupt national norms of race in order to argue for a different understanding of identity, this dissertation examines the deployment of abjection for alternative liberal and progressive goals. At the same time, this argument also looks to the writing of Southerners who embraced highly regressive and conservative ideologies, such as William Gilmore Simms, Thomas Dixon, and the Agrarians to argue for an alternative history and future that had hitherto been seen as contained within an abject historical topography. This dissertation argues that the topographies of Southern abjection are still essentail forces that impact and shape the the regional and national identity today as it struggles with how to define itself and its history

Limited diversity in natal origins of immature anadromous fish during ocean residency

Author Posting. © The Authors, 2009. This is the author's version of the work. It is posted here by permission of NRC Research Press for personal use, not for redistribution. The definitive version was published in Canadian Journal of Fisheries and Aquatic Sciences. 67 (2010): 1699-1707, doi:10.1139/F10-086.Variable migration patterns can play a significant role in promoting diverse life history traits among populations. However, population and stage specific movement patterns are generally unknown yet crucial aspects of life history strategies in many highly migratory species. We used a natural tag approach using geochemical signatures in otoliths to identify natal origins of one-year-old anadromous American shad (Alosa sapidissima) during ocean residency. Otolith signatures of migrants were compared to a database of baseline signatures from 20 source populations throughout their spawning range. Samples were dominated by fish from only two rivers, while all other potential source populations were nearly or completely absent. These data support the hypothesis that American shad exhibit diverse migratory behaviors and immature individuals from populations throughout the native range do not all mix on northern summer feeding grounds. Rather, our results suggest populations of anadromous fish are distributed heterogeneously at sea in the first year of life and thus may encounter different ocean conditions at a critical early life history stage.This work was funded by National Science Foundation grants OCE-0215905 and OCE-0134998 to SRT and by a WHOI Ocean Life Institute grant to BDW

A placebo-controlled proof-of-concept study of alirocumab on postprandial lipids and vascular elasticity in insulin-treated patients with type 2 diabetes mellitus

Aim: Type 2 diabetes mellitus (T2DM) is associated with an increased risk of cardiovascular disease (CVD) linked to atherogenic dyslipidaemia and postprandial hyperlipidaemia. Alirocumab, a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor, improves CVD risk by reducing the concentration of low-density lipoprotein-cholesterol (LDL-C). However, effects of PCK9 inhibitors on other aspects of diabetic dyslipidaemia, particularly in the postprandial situation, are less clear. Material and Methods: Twelve male patients with T2DM on an intensive insulin regimen completed a 6-week randomized, double-blind, placebo-controlled, proof-of-concept study. Participants received three biweekly dosages of subcutaneous alirocumab (150 mg) or placebo. Before and after the intervention, fasting and postprandial triglyceride (TG) plasma levels, apolipoprotein (apo) B48, lipoprotein composition isolated by ultracentrifugation, vascular function and markers of inflammation were evaluated. Results: Alirocumab treatment reduced fasting plasma TG levels (between group median change −24.7%; P = 0.018) and fasting apoB48 serum levels (−35.9%; P = 0.039) compared with placebo. Alirocumab reduced the plasma TG area under the curve (AUC) (−26.4%; P = 0.006) and apoB48 AUC (−55.7%; P = 0.046), as well as plasma TG incremental AUC (−21.4%; P = 0.04) and apoB48 incremental AUC (−26.8%; P = 0.02). In addition, alirocumab reduced fasting and postprandial TG levels in very low-density lipoprotein (VLDL) and LDL. Alirocumab improved fasting pulse wave velocity, but no changes in postprandial markers of inflammation were observed. Conclusions: In addition to the well-known LDL-C-reducing effects, 6 weeks of alirocumab treatment lowered both fasting and postprandial plasma TG levels by reducing the TG levels in VLDL and LDL and the concentration of intestinal remnants

Weak lensing, dark matter and dark energy

Weak gravitational lensing is rapidly becoming one of the principal probes of dark matter and dark energy in the universe. In this brief review we outline how weak lensing helps determine the structure of dark matter halos, measure the expansion rate of the universe, and distinguish between modified gravity and dark energy explanations for the acceleration of the universe. We also discuss requirements on the control of systematic errors so that the systematics do not appreciably degrade the power of weak lensing as a cosmological probe.Comment: Invited review article for the GRG special issue on gravitational lensing (P. Jetzer, Y. Mellier and V. Perlick Eds.). V3: subsection on three-point function and some references added. Matches the published versio

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results