Far-ultraviolet Spectroscopy of Venus and Mars at 4 A Resolution with the Hopkins Ultraviolet Telescope on Astro-2

Far-ultraviolet spectra of Venus and Mars in the range 820-1840 A at 4 A resolution were obtained on 13 and 12 March 1995, respectively, by the Hopkins Ultraviolet Telescope (HUT), which was part of the Astro-2 observatory on the Space Shuttle Endeavour. Longward of 1250 A, the spectra of both planets are dominated by emission of the CO Fourth Positive band system and strong OI and CI multiplets. In addition, CO Hopfield-Birge bands, B - X (0,0) at 1151 A and C - X (0,0) at 1088 A, are detected for the first time, and there is a weak indication of the E - X (0,0) band at 1076 A in the spectrum of Venus. The B - X band is blended with emission from OI 1152. Modeling the relative intensities of these bands suggests that resonance fluorescence of CO is the dominant source of the emission, as it is for the Fourth Positive system. Shortward of Lyman-alpha, other emission features detected include OII 834, OI lambda 989, HI Lyman-beta, and NI 1134 and 1200. For Venus, the derived disk brightnesses of the OI, OII, and HI features are about one-half of those reported by Hord et al. (1991) from Galileo EUV measurements made in February 1990. This result is consistent with the expected variation from solar maximum to solar minimum. The ArI 1048, 1066 doublet is detected only in the spectrum of Mars and the derived mixing ratio of Ar is of the order of 2%, consistent with previous determinations.Comment: 8 pages, 5 figures, accepted for publication in ApJ, July 20, 200

The consistency of the treatment effect of an ACE-inhibitor based treatment regimen in patients with vascular disease or high risk of vascular disease: A combined analysis of individual data of ADVANCE, EUROPA, and PROGRESS trials

AimsAngiotensin-converting enzyme (ACE) inhibitors have been shown to reduce cardiovascular risk in different groups of patients. Whether these effects can be generalized to the broad group of patients with vascular disease is unknown. Therefore, we undertook a combined analysis using individual data from ADVANCE, EUROPA, and PROGRESS to determine the consistency of the treatment effect of perindopril-based regimen in patients with vascular disease or at high risk of vascular disease.Methods and resultsWe studied all-cause mortality and major cardiovascular outcomes during a follow-up of about 4 years in the 29 463 patients randomly assigned a perindopril-based treatment regimen or placebo. The perindopril-based regimens were associated with a significant reduction in all-cause mortality [hazard ratio (HR) 0.89; 95 confidence interval (CI) 0.82-0.96; P = 0.006], cardiovascular mortality (HR 0.85; 95 CI 0.76-0.95; P = 0.004), non-fatal myocardial infarction (HR 0.80; 95 CI 0.71-0.90; P < 0.001), stroke (HR 0.82; 95 CI 0.74-0.92; P = 0.002), and heart failure (HR 0.84; 95 CI 0.72-0.96; P = 0.015). Results were consistent in subgroups with different clinical characteristics, concomitant medication use, and across all strata of baseline blood pressure.ConclusionThis study provides strong evidence for a consistent cardiovascular protection with an ACE-inhibitor treatment regimen (perindopril-indapamide) by improving survival and reducing the risk of major cardiovascular events across a broad spectrum of patients with vascular disease

Edge-control and surface-smoothness in sub-aperture polishing of mirror segments

This paper addresses two challenges in establishing a new process chain for polishing hexagonal segments for extremely large telescopes:- i) control of edge and corner profiles in small-tool polishing of hexagons, and ii) achieving the required smoothness of the bulk aspheric form. We briefly describe the performance of a CNC-grinding process used to create the off-axis asphere, which established the input-quality for subsequent processing. We then summarize processes for smoothing ground mid-spatials and pre- and corrective polishing using Zeeko CNC machines. The impact of two cases is considered; i) all processing stages are performed after the segment is cut hexagonal, and ii) final rectification of a hexagon after cutting from an aspherised roundel, as an alternative to ionfiguring. We then report on experimental results on witness samples demonstrating edges and corners close to the EELT segment specification, and results on a full-aperture spherical segment showing excellent surface smoothness. © 2012 SPIE

The what and where of adding channel noise to the Hodgkin-Huxley equations

One of the most celebrated successes in computational biology is the Hodgkin-Huxley framework for modeling electrically active cells. This framework, expressed through a set of differential equations, synthesizes the impact of ionic currents on a cell's voltage -- and the highly nonlinear impact of that voltage back on the currents themselves -- into the rapid push and pull of the action potential. Latter studies confirmed that these cellular dynamics are orchestrated by individual ion channels, whose conformational changes regulate the conductance of each ionic current. Thus, kinetic equations familiar from physical chemistry are the natural setting for describing conductances; for small-to-moderate numbers of channels, these will predict fluctuations in conductances and stochasticity in the resulting action potentials. At first glance, the kinetic equations provide a far more complex (and higher-dimensional) description than the original Hodgkin-Huxley equations. This has prompted more than a decade of efforts to capture channel fluctuations with noise terms added to the Hodgkin-Huxley equations. Many of these approaches, while intuitively appealing, produce quantitative errors when compared to kinetic equations; others, as only very recently demonstrated, are both accurate and relatively simple. We review what works, what doesn't, and why, seeking to build a bridge to well-established results for the deterministic Hodgkin-Huxley equations. As such, we hope that this review will speed emerging studies of how channel noise modulates electrophysiological dynamics and function. We supply user-friendly Matlab simulation code of these stochastic versions of the Hodgkin-Huxley equations on the ModelDB website (accession number 138950) and http://www.amath.washington.edu/~etsb/tutorials.html.Comment: 14 pages, 3 figures, review articl

Ultrasound in Emergency Medicine EMERGENCY BILIARY SONOGRAPHY: UTILITY OF COMMON BILE DUCT MEASUREMENT IN THE DIAGNOSIS OF CHOLECYSTITIS AND CHOLEDOCHOLITHIASIS

, Abstract-Background: Measurement of the common bile duct (CBD) has traditionally been considered an integral part of gallbladder sonography, but accurate identification of the CBD can be difficult for novice sonographers. Objective: To determine the prevalence of isolated sonographic CBD dilation in emergency department (ED) patients with cholecystitis or choledocholithiasis without laboratory abnormalities or other pathologic findings on biliary ultrasound. Methods: We conducted a retrospective chart review on two separate ED patient cohorts between June 2000 and June 2010. The first cohort comprised all ED patients undergoing a biliary ultrasound and subsequent cholecystectomy for presumed cholecystitis. The second cohort consisted of all ED patients receiving a biliary ultrasound who were ultimately diagnosed with choledocholithiasis. Ultrasound data and contemporaneous laboratory values were collected. Postoperative gallbladder pathology reports and endoscopic retrograde cholangiopancreatography (ERCP) reports were used as the criterion standard for final diagnosis. Results: Of 666 cases of cholecystitis, there were 251 (37.7%) with a dilated CBD &gt; 6 mm and only 2 cases (0.3%; 95% confidence interval [CI] 0.0-0.7%) of isolated CBD dilation with an otherwise negative ultrasound and normal laboratory values. Of 111 cases of choledocholithiasis, there were 80 (72.0%) with a dilated CBD and only 1 case (0.9%; 95% CI 0.0-2.7%) with an otherwise negative ultrasound and normal laboratory values. Conclusion: The prevalence of isolated sonographic CBD dilation in cholecystitis and choledocholithiasis is &lt;1%. Omission of CBD measurement is unlikely to result in missed cholecystitis or choledocholithiasis in the setting of a routine ED evaluation with an otherwise normal ultrasound and normal laboratory values. Ó 2013 Elsevier Inc

Clinical impairment in premanifest and early Huntington's disease is associated with regionally specific atrophy.

TRACK-HD is a multicentre longitudinal observational study investigating the use of clinical assessments and 3-Tesla magnetic resonance imaging as potential biomarkers for future therapeutic trials in Huntington's disease (HD). The cross-sectional data from this large well-characterized dataset provide the opportunity to improve our knowledge of how the underlying neuropathology of HD may contribute to the clinical manifestations of the disease across the spectrum of premanifest (PreHD) and early HD. Two hundred and thirty nine gene-positive subjects (120 PreHD and 119 early HD) from the TRACK-HD study were included. Using voxel-based morphometry (VBM), grey and white matter volumes were correlated with performance in four domains: quantitative motor (tongue force, metronome tapping, and gait); oculomotor [anti-saccade error rate (ASE)]; cognition (negative emotion recognition, spot the change and the University of Pennsylvania smell identification test) and neuropsychiatric measures (apathy, affect and irritability). After adjusting for estimated disease severity, regionally specific associations between structural loss and task performance were found (familywise error corrected, P < 0.05); impairment in tongue force, metronome tapping and ASE were all associated with striatal loss. Additionally, tongue force deficits and ASE were associated with volume reduction in the occipital lobe. Impaired recognition of negative emotions was associated with volumetric reductions in the precuneus and cuneus. Our study reveals specific associations between atrophy and decline in a range of clinical modalities, demonstrating the utility of VBM correlation analysis for investigating these relationships in HD

High dimensional endophenotype ranking in the search for major depression risk genes.

BACKGROUND: Despite overwhelming evidence that major depression is highly heritable, recent studies have localized only a single depression-related locus reaching genome-wide significance and have yet to identify a causal gene. Focusing on family-based studies of quantitative intermediate phenotypes or endophenotypes, in tandem with studies of unrelated individuals using categorical diagnoses, should improve the likelihood of identifying major depression genes. However, there is currently no empirically derived statistically rigorous method for selecting optimal endophentypes for mental illnesses. Here, we describe the endophenotype ranking value, a new objective index of the genetic utility of endophenotypes for any heritable illness. METHODS: Applying endophenotype ranking value analysis to a high-dimensional set of over 11,000 traits drawn from behavioral/neurocognitive, neuroanatomic, and transcriptomic phenotypic domains, we identified a set of objective endophenotypes for recurrent major depression in a sample of Mexican American individuals (n = 1122) from large randomly selected extended pedigrees. RESULTS: Top-ranked endophenotypes included the Beck Depression Inventory, bilateral ventral diencephalon volume, and expression levels of the RNF123 transcript. To illustrate the utility of endophentypes in this context, each of these traits were utlized along with disease status in bivariate linkage analysis. A genome-wide significant quantitative trait locus was localized on chromsome 4p15 (logarithm of odds = 3.5) exhibiting pleiotropic effects on both the endophenotype (lymphocyte-derived expression levels of the RNF123 gene) and disease risk. CONCLUSIONS: The wider use of quantitative endophenotypes, combined with unbiased methods for selecting among these measures, should spur new insights into the biological mechanisms that influence mental illnesses like major depression

Animal-related factors associated with moderate-to-severe diarrhea in children younger than five years in western Kenya: A matched case-control study

Background Diarrheal disease remains among the leading causes of global mortality in children younger than 5 years. Exposure to domestic animals may be a risk factor for diarrheal disease. The objectives of this study were to identify animal-related exposures associated with cases of moderate-to-severe diarrhea (MSD) in children in rural western Kenya, and to identify the major zoonotic enteric pathogens present in domestic animals residing in the homesteads of case and control children. Methodology/Principal findings We characterized animal-related exposures in a subset of case and control children (n = 73 pairs matched on age, sex and location) with reported animal presence at home enrolled in the Global Enteric Multicenter Study in western Kenya, and analysed these for an association with MSD. We identified potentially zoonotic enteric pathogens in pooled fecal specimens collected from domestic animals resident at children’s homesteads. Variables that were associated with decreased risk of MSD were washing hands after animal contact (matched odds ratio [MOR] = 0.2; 95% CI 0.08–0.7), and presence of adult sheep that were not confined in a pen overnight (MOR = 0.1; 0.02–0.5). Variables that were associated with increased risk of MSD were increasing number of sheep owned (MOR = 1.2; 1.0–1.5), frequent observation of fresh rodent excreta (feces/urine) outside the house (MOR = 7.5; 1.5–37.2), and participation of the child in providing water to chickens (MOR = 3.8; 1.2–12.2). Of 691 pooled specimens collected from 2,174 domestic animals, 159 pools (23%) tested positive for one or more potentially zoonotic enteric pathogens (Campylobacter jejuni, C. coli, non-typhoidal Salmonella, diarrheagenic E. coli, Giardia, Cryptosporidium, or rotavirus). We did not find any association between the presence of particular pathogens in household animals, and MSD in children. Conclusions and significance Public health agencies should continue to promote frequent hand washing, including after animal contact, to reduce the risk of MSD. Future studies should address specific causal relations of MSD with sheep and chicken husbandry practices, and with the presence of rodents