424 research outputs found
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Measurement of the Casimir Effect in the Cylinder-Sphere Geometry
The Casimir effect originates from the boundary effects on the quantum vacuum. The boundary modifies the allowed modes of zero-point, or virtual, photons. Current studies of the Casimir effect have taken place primarily between simple geometries such as the sphere-plate configuration. More complicated geometries will introduce modifications in the collective charge fluctuation anisotropy. In this work, we examine the Casimir force between a cylinder and a sphere in a UHV environment, examining the effects of the 1-D dimensionality of the cylinders. To reduce the ellipticity of the cylinders involved, we have used a glass optical fiber, coated with Au to provide a conductive surface. Co-location of the sphere and cylinder was achieved using a piezoelectric stage with a capacitive sensor controlled PID loop. To maintain cleanliness of the samples and minimize the effect of surface adsorbates, we utilize Ar ion bombardment and UV cleaning. We examine our results using the Proximity Force Approximation (PFA). The Casimir effect has broad implications for MEMS devices operating in the submicron regime
Mapping Sex Offender Addresses: The Utility of the Alaska Sex Offender Registry as a Research Data Base
The registration of sex offenders was part of a national effort to enhance public safety by permitting law enforcement officials to track the location of convicted sex offenders after their release. All fifty states have enacted legislation requiring persons convicted of various sex-related offenses to register with law enforcement agencies; many states also grant public access to all or a portion of their registries. This document reports on the Alaska Statistical Analysis Center's efforts to improve data accuracy in the Alaska Sex Offender Registry, maintained by the Alaska State Troopers, and to assess the registry's utility as a research tool.Bureau of Justice Statistics, Grant No. 1999-RU-RX-K006Background of the Project /
Research Methodology /
Results /
Utility: Spatial Justice Research /
APPENDICES /
A. Alaska’s Sex Offender Registration Law /
B. Establishment of a Central Registry of Sex Offenders in Alaska /
C. Definitions of Offenses for which Convicted Persons Must Register as Sex Offenders in Alask
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Experiments in the manufacture of newsprint from cottonwood and willow
Information reviewed and reaffirmed 1960. Original report dated 1955
Holographic phase transitions at finite baryon density
We use holographic techniques to study SU(Nc) super Yang-Mills theory coupled
to Nf << Nc flavours of fundamental matter at finite temperature and baryon
density. We focus on four dimensions, for which the dual description consists
of Nf D7-branes in the background of Nc black D3-branes, but our results apply
in other dimensions as well. A non-zero chemical potential mu or baryon number
density n is introduced via a nonvanishing worldvolume gauge field on the
D7-branes. Ref. [1] identified a first order phase transition at zero density
associated with `melting' of the mesons. This extends to a line of phase
transitions for small n, which terminates at a critical point at finite n.
Investigation of the D7-branes' thermodynamics reveals that (d mu / dn)_T <0 in
a small region of the phase diagram, indicating an instability. We comment on a
possible new phase which may appear in this region.Comment: 33 pages, 22 figure
Differences in 5'untranslated regions highlight the importance of translational regulation of dosage sensitive genes
Background: Untranslated regions (UTRs) are important mediators of post-transcriptional regulation. The length of UTRs and the composition of regulatory elements within them are known to vary substantially across genes, but little is known about the reasons for this variation in humans. Here, we set out to determine whether this variation, specifically in 5’UTRs, correlates with gene dosage sensitivity. Results: We investigate 5’UTR length, the number of alternative transcription start sites, the potential for alternative splicing, the number and type of upstream open reading frames (uORFs) and the propensity of 5’UTRs to form secondary structures. We explore how these elements vary by gene tolerance to loss-of-function (LoF; using the LOEUF metric), and in genes where changes in dosage are known to cause disease. We show that LOEUF correlates with 5’UTR length and complexity. Genes that are most intolerant to LoF have longer 5’UTRs, greater TSS diversity, and more upstream regulatory elements than their LoF tolerant counterparts. We show that these differences are evident in disease gene-sets, but not in recessive developmental disorder genes where LoF of a single allele is tolerated. Conclusions: Our results confirm the importance of post-transcriptional regulation through 5'UTRs in tight regulation of mRNA and protein levels, particularly for genes where changes in dosage are deleterious and lead to disease. Finally, to support gene-based investigation we release a web-based browser tool, VuTR, that supports exploration of the composition of individual 5'UTRs and the impact of genetic variation within them
Chronic electroconvulsive shock treatment elicits up-regulation of CRF and AVP mRNA in select populations of neuroendocrine neurons
The effects of repeated electroconvulsive seizures (ECS) on expression of mRNAs coding for corticotropin-releasing factor (CRF) and arginine vasopressin (AVP) in neuroendocrine neurons of the hypothalamo-pituitary-adrenocortical (HPA) axis and hypothalamo-neurohypophysial system (HNS) were assessed via semi-quantitative in situ hybridization histochemical analysis. Measures of mRNA content were accompanied by measurement of peptide- and hormone-expression in the relevant neuroendocrine systems. Following 7 daily ECS treatments, CRF mRNA was significantly increased in the medial parvocellular paraventricular nucleus (PVN) of treated rats relative to controls. CRF peptide content of whole PVN homogenates was decreased to 50% of control levels. Changes in CRF message and peptide levels were accompanied by increases in pituitary ACTH content and by elevated plasma corticosterone, suggesting ECS elicits long-term up-regulation of the HPA axis. AVP mRNA in the medial parvocellular PVN, which is known to up-regulate in response to HPA challenge by adrenalectomy, was not increased by ECS. Chronic ECS causes a clear up-regulation of HNS neurons of the supraoptic nucleus, characterized by increased AVP mRNA content, decreased AVP peptide content, and depletion of neurohypophysial AVP. However, no changes were observed in magnocellular vasopressinergic neurons of the PVN, indicating that magnocellular SON and PVN neurons respond differentially to stimulation by ECS. The data indicate that ECS is a potent stimulus for activation of select components of both the HPA axis and the HNS. As such, ECS provides a useful tool for examining mechanism underlying neuroendocrine processes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27688/1/0000072.pd
Review of the Constellation Level II Safety, Reliability, and Quality Assurance (SR&QA) Requirements Documents during Participation in the Constellation Level II SR&QA Forum
At the request of the Exploration Systems Mission Directorate (ESMD) and the Constellation Program (CxP) Safety, Reliability; and Quality Assurance (SR&QA) Requirements Director, the NASA Engineering and Safety Center (NESC) participated in the Cx SR&QA Requirements forum. The Requirements Forum was held June 24-26; 2008, at GRC's Plum Brook Facility. The forums purpose was to gather all stakeholders into a focused meeting to help complete the process of refining the CxP to refine its Level II SR&QA requirements or defining project-specific requirements tailoring. Element prime contractors had raised specific questions about the wording and intent of many requirements in areas they felt were driving costs without adding commensurate value. NESC was asked to provide an independent and thorough review of requirements that contractors believed were driving Program costs, by active participation in the forum. This document contains information from the forum
Dental practice satisfaction with preferred provider organizations
<p>Abstract</p> <p>Background</p> <p>Despite their increasing share of the dental insurance market, little is known about dental practices' satisfaction with preferred provider organizations (PPOs). This analysis examined practice satisfaction with dental PPOs and the extent to which satisfaction was a function of communications from the plan, claims handling and compensation.</p> <p>Methods</p> <p>Data were collected through telephone surveys with dental practices affiliated with MetLife between January 2002 and December 2004. Each respondent was asked a series of questions related to their satisfaction with a systematically selected PPO with which they were affiliated. Six different PPO plans had sufficient observations to allow for comparative analysis (total n = 4582). Multiple imputation procedures were used to adjust for item non-response.</p> <p>Results</p> <p>While the average level of overall satisfaction with the target plan fell between "very satisfied" and "satisfied," regression models revealed substantial differences in overall satisfaction across the 6 PPOs (p < .05). Statistically significant differences between plans in overall satisfaction were largely explained by differences in the perceived adequacy of compensation. However, differences in overall satisfaction involving two of the PPOs were also driven by satisfaction with claims handling.</p> <p>Conclusion</p> <p>Results demonstrate the importance of compensation to dental practice satisfaction with PPOs. However, these results also highlight the critical role of service-related factors in differentiating plans and suggest that there are important non-monetary dimensions of PPO performance that can be used to recruit and retain practices.</p
An Acidic Motif Retains Vesicular Monoamine Transporter 2 on Large Dense Core Vesicles
The release of biogenic amines from large dense core vesicles (LDCVs) depends on localization of the vesicular monoamine transporter VMAT2 to LDCVs. We now find that a cluster of acidic residues including two serines phosphorylated by casein kinase 2 is required for the localization of VMAT2 to LDCVs. Deletion of the acidic cluster promotes the removal of VMAT2 from LDCVs during their maturation. The motif thus acts as a signal for retention on LDCVs. In addition, replacement of the serines by glutamate to mimic phosphorylation promotes the removal of VMAT2 from LDCVs, whereas replacement by alanine to prevent phosphorylation decreases removal. Phosphorylation of the acidic cluster thus appears to reduce the localization of VMAT2 to LDCVs by inactivating a retention mechanism
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