A spurious pulse problem in a gas flow proportional counter

The source of spurious pulses in a 4[pi][beta] gas flow proportional counter was traced to impurities in the counting gas. The concentration of the impurities was so small that it was not obvious that this was the cause of the problem. It is suggested that the long term degradation in gas flow detectors may be due to the accumulation on the anode wires of microscopic deposits from the counting gas.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24481/1/0000756.pd

Multiwavelength Observations of 1ES 1959+650, One Year After the Strong Outburst of 2002

In April-May 2003, the blazar 1ES 1959+650 showed an increased level of X-ray activity. This prompted a multiwavelength observation campaign with the Whipple 10 m gamma-ray telescope, the Rossi X-ray Timing Explorer, the Bordeaux Optical Observatory, and the University of Michigan Radio Astrophysical Observatory. We present the multiwavelength data taken from May 2, 2003 to June 7, 2003 and compare the source characteristics with those measured during observations taken during the years 2000 and 2002. The X-ray observations gave a data set with high signal-to-noise light curves and energy spectra; however, the gamma-ray observations did not reveal a major TeV gamma-ray flare. Furthermore, we find that the radio and optical fluxes do not show statistically significant deviations from those measured during the 2002 flaring periods. While the X-ray flux and X-ray photon index appear correlated during subsequent observations, the apparent correlation evolved significantly between the years 2000, 2002, and 2003. We discuss the implications of this finding for the mechanism that causes the flaring activity.Comment: 17 pages, 6 figures, 2 table

Proteomic analysis of dietary restriction in yeast reveals a role for Hsp26 in lifespan extension

Dietary restriction (DR) has been shown to increase lifespan in organisms ranging from yeast to mammals. This suggests that the underlying mechanisms may be evolutionarily conserved. Indeed, upstream signalling pathways, such as TOR, are strongly linked to DR-induced longevity in various organisms. However, the downstream effector proteins that ultimately mediate lifespan extension are less clear. To shed light on this, we used a proteomic approach on budding yeast. Our reasoning was that analysis of proteome-wide changes in response to DR might enable the identification of proteins that mediate its physiological effects, including replicative lifespan extension. Of over 2500 proteins we identified by liquid chromatography-mass spectrometry, 183 were significantly altered in expression by at least 3-fold in response to DR. Most of these proteins were mitochondrial and/or had clear links to respiration and metabolism. Indeed, direct analysis of oxygen consumption confirmed that mitochondrial respiration was increased several-fold in response to DR. In addition, several key proteins involved in mating, including Ste2 and Ste6, were downregulated by DR. Consistent with this, shmoo formation in response to α-factor pheromone was reduced by DR, thus confirming the inhibitory effect of DR on yeast mating. Finally, we found that Hsp26, a member of the conserved small heat shock protein (sHSP) family, was upregulated by DR and that overexpression of Hsp26 extended yeast replicative lifespan. As overexpression of sHSPs in Caenorhabditis elegans and Drosophila has previously been shown to extend lifespan, our data on yeast Hsp26 suggest that sHSPs may be universally conserved effectors of longevity

The State of the Region: Hampton Roads 2020

[From the introductory material] This is Old Dominion University’s 21st annual State of the Region Report. While it represents the work of many people connected in various ways to the university, the report does not constitute an official viewpoint of Old Dominion, its president, John R. Broderick, the Board of Visitors, the Strome College of Business or the generous donors who support the activities of the Dragas Center for Economic Analysis and Policy. Although our devotion to this work remains steadfast, our enthusiasm, admittedly, has been dampened by the COVID-19 pandemic and the toll it has taken on the region, Commonwealth and nation. In consideration of the national conversation on race and inequality, we have included additional material to shed light on how race affects economic outcomes in Hampton Roads. Hampton Roads plays a significant role in our nation’s national security, provides college education to thousands of Virginians, is working to adapt to sea level rise and is culturally diverse. There are challenges, of course, but, as the adage goes, challenge and opportunity are two sides of the same coin. To adapt, improve and overcome, we must understand where we are and where we want to go. Our work seeks to contribute to this conversation without glossing over the challenges we face

Systematic review of interventions to encourage careers in academic medicine

Aims: Academic medicine is a career route that historically struggles to recruit and retain suitable doctors. The aim of this paper is to review the evidence for interventions to encourage careers in academic medicine by way of a descriptive systematic review. Methods: Key databases were searched in February 2017. Studies that evaluated interventions to encourage careers in academic medicine and that used a pre–post analysis or included a comparison group were included. Interventions reporting only learner satisfaction were excluded. The review was specific to medical students and graduates. Results: Twenty-four studies were identified for inclusion within the review. The included studies identified interventions across five domains: postgraduate funding, postgraduate training, mentoring, undergraduate interventions, and institutional change. The papers varied in terms of strength of conclusion and method of analysis with broad, structured, well-funded programs having the most palpable results. Conclusions: The five domains identified offer a framework that can be used by institutions who wish to develop similar programs. It also offers a body of research on which an evidence base can be built

The multiple team formation problem using sociometry

The Team Formation problem (TFP) has become a well-known problem in the OR literature over the last few years. In this problem, the allocation of multiple individuals that match a required set of skills as a group must be chosen to maximise one or several social positive attributes. Specifically, the aim of the current research is two-fold. First, two new dimensions of the TFP are added by considering multiple projects and fractions of people's dedication. This new problem is named the Multiple Team Formation Problem (MTFP). Second, an optimization model consisting in a quadratic objective function, linear constraints and integer variables is proposed for the problem. The optimization model is solved by three algorithms: a Constraint Programming approach provided by a commercial solver, a Local Search heuristic and a Variable Neighbourhood Search metaheuristic. These three algorithms constitute the first attempt to solve the MTFP, being a variable neighbourhood local search metaheuristic the most efficient in almost all cases. Applications of this problem commonly appear in real-life situations, particularly with the current and ongoing development of social network analysis. Therefore, this work opens multiple paths for future research

Differential diagnosis of illness in travelers arriving from sierra Leone, Liberia, or guinea: A cross-sectional study from the Geosentinel surveillance network

Background: The largest-ever outbreak of Ebola virus disease (EVD), ongoing in West Africa since late 2013, has led to export of cases to Europe and North America. Clinicians encountering ill travelers arriving from countries with widespread Ebola virus transmission must be aware of alternate diagnoses associated with fever and other nonspecific symptoms. Objective: To define the spectrum of illness observed in persons returning from areas of West Africa where EVD transmission has been widespread. Design: Descriptive, using GeoSentinel records. Setting: 57 travel or tropical medicine clinics in 25 countries. Patients: 805 ill returned travelers and new mmigrants from Sierra Leone, Liberia, or Guinea seen between September 2009 and August 2014. Measurements: Frequencies of demographic and travelrelated characteristics and illnesses reported. Results: The most common specific diagnosis among 770 nonimmigrant travelers was malaria (n = 310 [40.3%]), with Plasmodium falciparum or severe malaria in 267 (86%) and non–P. falciparum malaria in 43 (14%). Acute diarrhea was the second most common diagnosis among nonimmigrant travelers (n= 95 [12.3%]). Such common diagnoses as upper respiratory tract infection, urinary tract infection, and influenza-like illness occurred in only 26, 9, and 7 returning travelers, respectively. Few instances of typhoid fever (n = 8), acute HIV infection (n = 5), and dengue (n = 2) were encountered. Limitation: Surveillance data collected by specialist clinics may not be representative of all ill returned travelers. Conclusion: Although EVD may currently drive clinical evaluation of ill travelers arriving from Sierra Leone, Liberia, and Guinea, clinicians must be aware of other more common, potentially fatal diseases. Malaria remains a common diagnosis among travelers seen at GeoSentinel sites. Prompt exclusion of malaria and other life-threatening conditions is critical to limiting morbidity and mortality

Gaia GraL: Gaia DR2 Gravitational Lens Systems. VII. XMM-Newton Observations of Lensed Quasars

© 2022. The Author(s). Published by the American Astronomical Society. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.3847/1538-4357/ac4476We present XMM-Newton X-ray observations of nine confirmed lensed quasars at 1 ≲ z ≲ 3 identified by the Gaia Gravitational Lens program. Eight systems are strongly detected, with 0.3-8.0 keV fluxes F 0.3-8.0 ≳ 5 ×10-14 erg cm-2 s-1. Modeling the X-ray spectra with an absorbed power law, we derive power-law photon indices and 2-10 keV luminosities for the eight detected quasars. In addition to presenting sample properties for larger quasar population studies and for use in planning for future caustic-crossing events, we also identify three quasars of interest: a quasar that shows evidence of flux variability from previous ROSAT observations, the most closely separated individual lensed sources resolved by XMM-Newton, and one of the X-ray brightest quasars known at z > 3. These sources represent the tip of the discoveries that will be enabled by SRG/eROSITA.Peer reviewe