X-Ray Scanner for Atlas Barrel TRT Modules

X-ray scanners for gain mapping of ATLAS Barrel Transition Radiation Tracker (TRT) modules were developed at Hampton University for quality assurance purposes. Gas gain variations for each straw of the TRT modules were used to decide whether wires should be removed or restrung, and to evaluate overall module quality.Comment: Conference proceeding in the XXIV Physics in Collisions Conference (PIC04), Boston, USA, June 2004, 3 pages, LaTeX, 6 eps figures. MONP0

On the Quantization of Multilinear Momentum Observables

A generally accepted set of axioms of quantization is introduced and applied to the quantization of the multilinear momentum observables so as to delimit the possible forms of the corresponding quantum operators. This analysis leads to a canonical decomposition of the quantum observables into a series of symmetric operators each of which is determined by an unknown auxilliary tensor generated by the multilinear momentum. Methods of removing the residual indeterminates in the differential operators are then critically reviewed, and a particular choice illustrated by means of examples defined on the real line

Cities, Inclusion and Exactions

Cities across the country are adopting mandatory inclusionary zoning. Yet, consensus about the appropriate constitutional standard to measure the propriety of mandatory inclusionary zoning has not been fully reached. Under one doctrinal lens, inclusionary zoning is a valid land use regulation adopted to ensure a proper balance of housing within the jurisdiction. Under another doctrinal lens, challengers seek to characterize inclusionary zoning as an exaction, a discretionary condition subject to a heightened standard of review addressing the specific negative impact caused by an individual project on the supply of affordable housing in a jurisdiction. Drawing from the experience of Baltimore, Maryland’s inclusionary zoning ordinance, this Article considers the impact that the uncertainty in the law may have had on the type of inclusionary zoning ordinance adopted by the city. This Article argues that the conversation about inclusionary zoning, land use regulation, and exactions has been formulated in the context of imagery about development that leaves places like Baltimore out. The imagery in these narratives is of an individual landowner powerless in the face of government overreach. The reality is different in those places where land developers are not powerless and instead are often politically influential repeat players. Thus, the real problem presented may be not how to craft doctrine to prevent cities from asking too much of developers, but instead to craft doctrine that ensures cities do not give away too much

G protein-coupled receptor kinase 2 regulates mitochondrial bioenergetics and impairs myostatin-mediated autophagy in muscle cells

G protein-coupled receptor kinase 2 (GRK2) is an important protein involved in β-adrenergic receptor desensitization. In addition, studies have shown GRK2 can modulate different metabolic processes in the cell. For instance, GRK2 has been recently shown to promote mitochondrial biogenesis and increase ATP production. However, the role of GRK2 in skeletal muscle and the signaling mechanisms that regulate GRK2 remain poorly understood. Myostatin is a well-known myokine that has been shown to impair mitochondria function. Here, we have assessed the role of myostatin in regulating GRK2 and the subsequent downstream effect of myostatin regulation of GRK2 on mitochondrial respiration in skeletal muscle. Myostatin treatment promoted the loss of GRK2 protein in myoblasts and myotubes in a time- and dose-dependent manner, which we suggest was through enhanced ubiquitin-mediated protein loss, as treatment with proteasome inhibitors partially rescued myostatin-mediated loss of GRK2 protein. To evaluate the effects of GRK2 on mitochondrial respiration, we generated stable myoblast lines that overexpress GRK2. Stable overexpression of GRK2 resulted in increased mitochondrial content and enhanced mitochondrial/oxidative respiration. Interestingly, although overexpression of GRK2 was unable to prevent myostatin-mediated impairment of mitochondrial respiratory function, elevated levels of GRK2 blocked the increased autophagic flux observed following treatment with myostatin. Overall, our data suggest a novel role for GRK2 in regulating mitochondria mass and mitochondrial respiration in skeletal muscle

The Plasmodium berghei Ca(2+)/H(+) exchanger, PbCAX, is essential for tolerance to environmental Ca(2+) during sexual development.

Ca(2+) contributes to a myriad of important cellular processes in all organisms, including the apicomplexans, Plasmodium and Toxoplasma. Due to its varied and essential roles, free Ca(2+) is tightly regulated by complex mechanisms. These mechanisms are therefore of interest as putative drug targets. One pathway in Ca(2+) homeostatic control in apicomplexans uses a Ca(2+)/H(+) exchanger (a member of the cation exchanger family, CAX). The P. falciparum CAX (PfCAX) has recently been characterised in asexual blood stage parasites. To determine the physiological importance of apicomplexan CAXs, tagging and knock-out strategies were undertaken in the genetically tractable T. gondii and P. berghei parasites. In addition, a yeast heterologous expression system was used to study the function of apicomplexan CAXs. Tagging of T. gondii and P. berghei CAXs (TgCAX and PbCAX) under control of their endogenous promoters could not demonstrate measureable expression of either CAX in tachyzoites and asexual blood stages, respectively. These results were consistent with the ability of parasites to tolerate knock-outs of the genes for TgCAX and PbCAX at these developmental stages. In contrast, PbCAX expression was detectable during sexual stages of development in female gametocytes/gametes, zygotes and ookinetes, where it was dispersed in membranous networks within the cytosol (with minimal mitochondrial localisation). Furthermore, genetically disrupted parasites failed to develop further from "round" form zygotes, suggesting that PbCAX is essential for ookinete development and differentiation. This impeded phenotype could be rescued by removal of extracellular Ca(2+). Therefore, PbCAX provides a mechanism for free living parasites to multiply within the ionic microenvironment of the mosquito midgut. Ca(2+) homeostasis mediated by PbCAX is critical and suggests plasmodial CAXs may be targeted in approaches designed to block parasite transmission

Reconsidering the Reality of Southeastern Mesoamerica: Continuity, Diversity, and Inter-Valley Interaction in Western Honduras

The late fifth century AD was a time of rapid transformation in non-­‐Maya southeastern Mesoamerica. From this time forward, the landscape of western Honduras would become filled with increasingly complex polities and rising populations. So too is there evidence for a distinctive change in material culture, such as the development of widely shared regional polychrome ceramic traditions and the stabilization of obsidian exchange networks. Arguably, more than any other period in prehistory, it is during the Late Classic that a unique cultural identity emerges from this part of southeastern Mesoamerica. In this paper we seek to answer the question, can we characterize the diverse peoples and communities of Late Classic western Honduras as belonging to a culture area of shared affiliation and concordant identities, or is “southeastern Mesoamerica” nothing more than a geographic designation, which encompasses a diversity of strategies just different enough to defy uniform classification? To address this question we place the findings of our own research in the broader context of the long-­‐term research projects conducted by our colleagues since the 1980s. In particular, we emphasize the inter-­‐valley interactions among these polities to illuminate the shared and divergent paths taken by these communities during this period

Above all, do no harm: Towards more ethical ways of being and acting in psychological formulation

Recent evidence seems to suggest mental health service users can be at risk of persistent harm as a result of psychological interventions. This article analyses ways of addressing harm by using the ‘lenses’ of four ethical theories to view psychological formulation

Coulomb interactions in single, charged self-assembled quantum dots: radiative lifetime and recombination energy

We present results on the charge dependence of the radiative recombination lifetime, Tau, and the emission energy of excitons confined to single self-assembled InGaAs quantum dots. There are significant dot-to-dot fluctuations in the lifetimes for a particular emission energy. To reach general conclusions, we present the statistical behavior by analyzing data recorded on a large number of individual quantum dots. Exciton charge is controlled with extremely high fidelity through an n-type field effect structure, providing access to the neutral exciton (X0), the biexciton (2X0) and the positively (X1+) and negatively (X1-) charged excitons. We find significant differences in the recombination lifetime of each exciton such that, on average, Tau(X1-) / Tau(X0) = 1.25, Tau(X1+) / Tau(X0) = 1.58 and Tau(2X0) / Tau(X0) = 0.65. We attribute the change in lifetime to significant changes in the single particle hole wave function on charging the dot, an effect more pronounced on charging X0 with a single hole than with a single electron. We verify this interpretation by recasting the experimental data on exciton energies in terms of Coulomb energies. We show directly that the electron-hole Coulomb energy is charge dependent, reducing in value by 5-10% in the presence of an additional electron, and that the electron-electron and hole-hole Coulomb energies are almost equal.Comment: 8 pages, 7 figures, submitted to Phys. Rev.