Extraction efficiency of drifting electrons in a two-phase xenon time projection chamber

We present a measurement of the extraction efficiency of quasi-free electrons from the liquid into the gas phase in a two-phase xenon time-projection chamber. The measurements span a range of electric fields from 2.4 to 7.1 kV/cm in the liquid xenon, corresponding to 4.5 to 13.1 kV/cm in the gaseous xenon. Extraction efficiency continues to increase at the highest extraction fields, implying that additional charge signal may be attained in two-phase xenon detectors through careful high-voltage engineering of the gate-anode region

Estrogen-related and other disease diagnoses preceding Parkinson’s disease

PURPOSE: Estrogen exposure has been associated with the occurrence of Parkinson's disease (PD), as well as many other disorders, and yet the mechanisms underlying these relations are often unknown. While it is likely that estrogen exposure modifies the risk of various diseases through many different mechanisms, some estrogen-related disease processes might work in similar manners and result in association between the diseases. Indeed, the association between diseases need not be due only to estrogen-related factors, but due to similar disease processes from a variety of mechanisms. PATIENTS AND METHODS: All female Parkinson's disease cases between 1982 and 2007 (n = 12,093) were identified from the Danish National Registry of Patients, along with 10 controls matched by years of birth and enrollment. Conditional logistic regressions (CLR) were used to calculate risk of PD after diagnosis of the estrogen-related diseases, endometriosis and osteoporosis, conditioning on years of birth and enrollment. To identify novel associations between PD and any other preceding conditions, CLR was also used to calculate the odds ratios (ORs) for risk of PD for 202 different categories of preceding disease diagnoses. Empirical Bayes methods were used to identify the robust associations from the over 200 associations produced by this analysis. RESULTS: We found a positive association between osteoporosis and osteoporotic fractures and PD (OR = 1.18, 95% confidence interval [CI] of 1.08–1.28), while a lack of association was observed between endometriosis and PD (OR = 1.37, 95% CI 0.99–1.90). Using empirical Bayes analyses, 24 additional categories of diseases, likely unrelated to estrogen exposure, were also identified as potentially associated with PD. CONCLUSION: We identified several novel associations, which may provide insight into common causal mechanisms between the diseases or greater understanding of potential early preclinical signs of PD. In particular, the associations with several categories of mental disorders suggest that these may be early warning signs of PD onset or these diseases (or the causes of these diseases) may predispose to PD.US Public Health Service (R01 NS36711-09); Robert P. and Judith N. Goldberg Foundation; Aarhus University Hospital Department of Clinical Epidemiology's Research Foundatio

Two-stage approach for identifying single-nucleotide polymorphisms associated with rheumatoid arthritis using random forests and Bayesian networks

We used the simulated data set from Genetic Analysis Workshop 15 Problem 3 to assess a two-stage approach for identifying single-nucleotide polymorphisms (SNPs) associated with rheumatoid arthritis (RA). In the first stage, we used random forests (RF) to screen large amounts of genetic data using the variable importance measure, which takes into account SNP interaction effects as well as main effects without requiring model specification. We used the simulated 9187 SNPs mimicking a 10 K SNP chip, along with covariates DR (the simulated DRB1 gentoype), smoking, and sex as input to the RF analyses with a training set consisting of 750 unrelated RA cases and 750 controls. We used an iterative RF screening procedure to identify a smaller set of variables for further analysis. In the second stage, we used the software program CaMML for producing Bayesian networks, and developed complex etiologic models for RA risk using the variables identified by our RF screening procedure. We evaluated the performance of this method using independent test data sets for up to 100 replicates

Pathway analysis following association study

Genome-wide association studies often emphasize single-nucleotide polymorphisms with the smallest p-values with less attention given to single-nucleotide polymorphisms not ranked near the top. We suggest that gene pathways contain valuable information that can enable identification of additional associations. We used gene set information to identify disease-related pathways using three methods: gene set enrichment analysis (GSEA), empirical enrichment p-values, and Ingenuity pathway analysis (IPA). Association tests were performed for common single-nucleotide polymorphisms and aggregated rare variants with traits Q1 and Q4. These pathway methods were evaluated by type I error, power, and the ranking of the VEGF pathway, the gene set used in the simulation model. GSEA and IPA had high power for detecting the VEGF pathway for trait Q1 (91.2% and 93%, respectively). These two methods were conservative with deflated type I errors (0.0083 and 0.0072, respectively). The VEGF pathway ranked 1 or 2 in 123 of 200 replicates using IPA and ranked among the top 5 in 114 of 200 replicates for GSEA. The empirical enrichment method had lower power and higher type I error. Thus pathway analysis approaches may be useful in identifying biological pathways that influence disease outcomes

Genetic Correlates of Brain Aging on MRI and Cognitive Test Measures: A Genome-Wide Association and Linkage Analysis in the Framingham Study

BACKGROUND: Brain magnetic resonance imaging (MRI) and cognitive tests can identify heritable endophenotypes associated with an increased risk of developing stroke, dementia and Alzheimer's disease (AD). We conducted a genome-wide association (GWA) and linkage analysis exploring the genetic basis of these endophenotypes in a community-based sample. METHODS: A total of 705 stroke- and dementia-free Framingham participants (age 62 +9 yrs, 50% male) who underwent volumetric brain MRI and cognitive testing (1999–2002) were genotyped. We used linear models adjusting for first degree relationships via generalized estimating equations (GEE) and family based association tests (FBAT) in additive models to relate qualifying single nucleotide polymorphisms (SNPs, 70,987 autosomal on Affymetrix 100K Human Gene Chip with minor allele frequency ≥ 0.10, genotypic call rate ≥ 0.80, and Hardy-Weinberg equilibrium p-value ≥ 0.001) to multivariable-adjusted residuals of 9 MRI measures including total cerebral brain (TCBV), lobar, ventricular and white matter hyperintensity (WMH) volumes, and 6 cognitive factors/tests assessing verbal and visuospatial memory, visual scanning and motor speed, reading, abstract reasoning and naming. We determined multipoint identity-by-descent utilizing 10,592 informative SNPs and 613 short tandem repeats and used variance component analyses to compute LOD scores. RESULTS: The strongest gene-phenotype association in FBAT analyses was between SORL1 (rs1131497; p = 3.2 × 10-6) and abstract reasoning, and in GEE analyses between CDH4 (rs1970546; p = 3.7 × 10-8) and TCBV. SORL1 plays a role in amyloid precursor protein processing and has been associated with the risk of AD. Among the 50 strongest associations (25 each by GEE and FBAT) were other biologically interesting genes. Polymorphisms within 28 of 163 candidate genes for stroke, AD and memory impairment were associated with the endophenotypes studied at p < 0.001. We confirmed our previously reported linkage of WMH on chromosome 4 and describe linkage of reading performance to a marker on chromosome 18 (GATA11A06), previously linked to dyslexia (LOD scores = 2.2 and 5.1). CONCLUSION: Our results suggest that genes associated with clinical neurological disease also have detectable effects on subclinical phenotypes. These hypothesis generating data illustrate the use of an unbiased approach to discover novel pathways that may be involved in brain aging, and could be used to replicate observations made in other studies.National Institutes of Health National Center for Research Resources Shared Instrumentation grant (ISI0RR163736-01A1); National Heart, Lung, and Blood Institute's Framingham Heart Study (N01-HC-25195); National Institute of Aging (5R01-AG08122, 5R01-AG16495); National Institute of Neurological Disorders and Stroke (5R01-NS17950

Development and Dissemination of a New Multidisciplinary Undergraduate Curriculum in Digital Forensics

The Information Trust Institute (ITI) at the University of Illinois at Urbana-Champaign is developing an entirely new multidisciplinary undergraduate curriculum on the topic of digital forensics, and this paper presents the findings of the development process, including initial results and evaluation of a pilot offering of the coursework to students. The curriculum consists of a four-course sequence, including introductory and advanced lecture courses with parallel laboratory courses, followed by an advanced course. The content has been designed to reflect both the emerging national standards and the strong multidisciplinary character of the profession of digital forensics, and includes modules developed collaboratively by faculty experts in multiple fields of computer science, law, psychology, social sciences, and accountancy. A preliminary plan for the introductory course was presented to a workshop of digital forensics experts in May 2013 and received their strong approval. Pilot versions of the introductory and introductory lab courses were taught to a mixture of computer science and law students at the University of Illinois in the fall of 2013, and were very positively received by the students, who made it clear that they appreciated the multidisciplinary approach. The curriculum, which is designed to obviate the need for expensive labs or team-teaching by specialized faculty, will be made available to other colleges and universities in order to improve the content and quality of existing digital forensics programs, to inspire and greatly facilitate the creation of new programs, and, ultimately, to increase the number of educated practitioners. The developed resources can be used as the basis for future academic programs, distance learning, and multidisciplinary, multi-institutional programs that meet evolving digital forensics educational standards. Much of the material, including a virtual laboratory, will be provided on-line. Introductory course materials will be distributed to other institutions beginning in the summer of 2014; advanced course materials should be available for distribution in 2015. Related outreach activities have been undertaken and will be continued. Keywords: Digital forensics, Computer forensics, Curriculum development, Curriculum standards, Education standards, Training standards, Undergraduate education, Interdisciplinary studie

An Analytic Model for Estimating the First Contact Resistance Needed to Avoid Damaging ESD During Spacecraft Docking in GEO

NASAs Gateway program will involve spacecraft (s/c) docking in the outer radiation belt in order to transfer Gateway elements between s/c for transport to lunar orbit. The charging of these s/c to different potentials prior to docking raises the possibility of a damaging electrostatic discharge (ESD) at the time of first contact between the s/c. A proposed mitigation strategy is for first contact to occur prior to docking through a resistor with resistance R that would lower the potential difference at an optimal rate to a sufficiently low value to prevent ESD damage. The coupling of s/c by a resistor can be modeled by SPIS, but for realistic two s/c models SPIS can take hours to simulate the evolution of the s/c surface charges and potentials to an equilibrium state. Our objective is to develop a simpler model of s/c resistive coupling that runs orders of magnitude faster while providing useful first design estimates of the time variation of the s/c potentials, current through the resistor, and how these vary with R and s/c configuration This configuration is defined by the relative separation and orientation of the s/c, and their solar illumination. The configuration and geometry of the s/c determine their capacitive coupling. The s/c capacitances are computed using Nascap-2K. This poster presents the first version of such a model, and initial tests

The Ursinus Weekly, December 4, 1961

Dr. Philip began choral tradition with one hundred voices in \u2738 • Handel\u27s oratorio written in Dublin; German\u27s contemporaries judged his operas best • Wedding present is job well done • Temple psych professor to speak tonight to PSEA • Wide experience, rich talent apply to Thursday\u27s Messiah soloists • Ursinus\u27 24th Messiah hails Christmas season • Who\u27s Who accepts fourteen students • Directors approve insurance policy • Grant, Draeger crowned lord, lady; Griffin named \u2762 permanent prexy • Y executive sees need for more YMCA publicity • Lists posted this week for Christmas banquet • Editorial: Full house; Distributor of the ticket • Latest student concert presents popular pieces • Ursinus in the past • The bear stood up • Syracuse, Miami to battle in third Liberty Bowl game • Mrs. William Ursinus Helfferich \u2793, saluted in Alumni Journal article • Young Republicans show President at summit • Texas take off preparations set for Ursinus\u27 chef • Schedule squeezed for Bowl queen before game day • Community cooperation keynotes Fire Company • Peace Corps information discussed by an interested Ursinus senior • Alpha Psi admits three members • YM-YWCA campus affairs plans bridge tournament • Volleyball intramurals begin with strong entries • Folwell, Shearer captains of 1962 U.C. color guard • Bear basketeers edge Eastern 79-78 as Walt Dryfoos stages scoring spree • Coach to stress speed, substitution for Bear cagers • Rough rebounding, unorthodox moves key to Dryfoos\u27 basketball success • Pi Nu inducts fourteen; Music enthusiasts honored • Greek gleaningshttps://digitalcommons.ursinus.edu/weekly/1306/thumbnail.jp

Spacecraft Charging during Docking Operations in the Outer Radiation Belt

Spacecraft charging can occur when a spacecraft vehicle is subject to space plasma environments and varying sunlit conditions. The trajectory of the spacecraft will determine the specific impinging environment while the spacecraft geometry and material properties determine the susceptibility to various charging issues. In general, spacecraft charging is separated into two categories, surface charging (~100keV)

An Analytic Model for Estimating the First Contact Resistance Needed to Avoid Damaging ESD During Spacecraft Docking in GEO

NASAs Gateway program is to involve spacecraft (s/c) docking in the outer radiation belt in order to transfer Gateway elements between s/c for transport to lunar orbit. The charging of these s/c to different potentials prior to docking raises the possibility of a damaging electrostatic discharge (ESD) at the time of first contact between the s/c. A proposed mitigation strategy is for first contact to occur prior to docking through a resistor with resistance R that would lower the potential difference at an optimal rate to a sufficiently low value to prevent a damaging ESD. The coupling of s/c by a resistor can be modeled by SPIS (Spacecraft Plasma Interaction System), but for realistic two s/c models SPIS can take hours to simulate the evolution of the s/c surface charges and potentials to an equilibrium state. Our objective is to develop a simpler model of s/c resistive coupling that runs orders of magnitude faster while providing useful first design estimates of the time variation of the s/c potentials, current through the resistor, and how these vary with R and s/c configuration. This configuration is defined by the relative separation and orientation of the s/c, and their solar illumination. The configuration and geometry of the s/c determine their capacitive coupling. The s/c capacitances are computed using Nascap-2K. This abstract and the associated poster describe the first version of such a model, and initial tests