Localized precipitation and runoff on Mars

We use the Mars Regional Atmospheric Modeling System (MRAMS) to simulate lake storms on Mars, finding that intense localized precipitation will occur for lake size >=10^3 km^2. Mars has a low-density atmosphere, so deep convection can be triggered by small amounts of latent heat release. In our reference simulation, the buoyant plume lifts vapor above condensation level, forming a 20km-high optically-thick cloud. Ice grains grow to 200 microns radius and fall near (or in) the lake at mean rates up to 1.5 mm/hr water equivalent (maximum rates up to 6 mm/hr water equivalent). Because atmospheric temperatures outside the surface layer are always well below 273K, supersaturation and condensation begin at low altitudes above lakes on Mars. In contrast to Earth lake-effect storms, lake storms on Mars involve continuous precipitation, and their vertical velocities and plume heights exceed those of tropical thunderstorms on Earth. Convection does not reach above the planetary boundary layer for lakes O(10^2) mbar. Instead, vapor is advected downwind with little cloud formation. Precipitation occurs as snow, and the daytime radiative forcing at the land surface due to plume vapor and storm clouds is too small to melt snow directly (<+10 W/m^2). However, if orbital conditions are favorable, then the snow may be seasonally unstable to melting and produce runoff to form channels. We calculate the probability of melting by running thermal models over all possible orbital conditions and weighting their outcomes by probabilities given by Laskar et al., 2004. We determine that for an equatorial vapor source, sunlight 15% fainter than at present, and snowpack with albedo 0.28 (0.35), melting may occur with 4%(0.1%) probability. This rises to 56%(12%) if the ancient greenhouse effect was modestly (6K) greater than today.Comment: Submitted to JGR Planet

Spin-Crossover in a New Iron(II)/Di(pyrazolyl)pyridine Complex with a Terpyridine Embrace Lattice. Thermally Induced Excited Spin State Trapping and Clarification of a Structure−Function Correlation

The complex salts [FeL2]X2 (1X2; L = 2,6-di{4-fluoropyrazol-1-yl}pyridine; X– = BF4– or ClO4–) exhibit abrupt spin-transitions with narrow thermal hysteresis, at T1/2 = 164 K (X– = BF4–) and 148 K (X– = ClO4–). The transition in 1[ClO4]2 is complicated by efficient thermally induced excited spin-state trapping (TIESST) of its high-spin state below ca. 120 K, and the fully low-spin state was achieved only inside the magnetometer at a scan rate of 0.5 K min–1. Crystals of 1[BF4]2 are tetragonal (P421c, Z = 2; phase 1) at 300 K but transform to a highly twinned monoclinic phase 2 (P21, Z = 2) at 285 ± 5 K. These are forms of the “terpyridine embrace” crystal lattice, which often affords cooperative spin-transitions in iron/di(pyrazolyl)pyridine complexes. Phase 2 of high-spin 1[BF4]2 shows a significant temperature dependence by powder diffraction, which reflects increased canting of the monoclinic unit cell as the temperature is lowered. In contrast, 1[ClO4]2 retains phase 2 between 100 and 300 K, and was crystallographically characterized in its thermally trapped metastable high-spin state at 100 K, as well as its thermodynamic high- and low-spin forms at higher temperatures. The spin-crossover transition temperature in 1[ClO4]2 and related compounds correlates well with a parameter describing angular changes to the metal coordination sphere during the transition but not with other commonly used structural indices. The TIESST metastable high-spin state of 1[ClO4]2 shows no single molecule magnet properties at 2 K

Strength of public preferences for endovascular or open aortic aneurysm repair

Background This study evaluated public preferences for the treatment processes for abdominal aortic aneurysm repair in order to allow them to be incorporated into a cost‐effectiveness analysis. Methods This was a telephone survey using a trade‐off method in UK resident adults (aged at least 18 years) with no previous diagnosis of a vascular condition. Results Some 167 of 209 participants (79·9 per cent) stated that they would prefer endovascular aneurysm repair (EVAR), 40 (19·1 per cent) preferred open surgery and two (1·0 per cent) stated no preference. Participants preferred EVAR because of the less invasive nature of the intervention and quicker recovery. Participants preferring open surgery cited reasons such as having a single follow‐up appointment, and a procedure that felt more permanent. When participants were asked to make a sacrifice in order to have their preferred treatment, 122 (58·4 per cent) favoured EVAR, 18 (8·6 per cent) favoured open surgery and 69 (33·0 per cent) had no preference. Those preferring EVAR were willing to give up a mean of 0·135 expected quality‐adjusted life‐years (QALYs) to have EVAR, compared with a willingness to give up 0·033 expected QALYs among those preferring open repair. Conclusion These results indicate a clear preference for EVAR over open surgery for aortic aneurysm

Data to support study of Spin-Crossover in a New Iron(II)/Di(pyrazolyl)pyridine Complex with a Terpyridine Embrace Lattice

[FeL2]X2 ( L = 2,6-di{4-fluoropyrazol-1-yl}pyridine) exhibit hysteretic spin-transitions at T½ = 164 (X = BF4) and 148 K (X = ClO4). The perchlorate salt shows efficient TIESST below 120 K, and was characterized in its thermally trapped high-spin form, as well as in its thermodynamic high- and low-spin states

Science-Driven Network Requirements for ESnet

The Energy Sciences Network (ESnet) is the primary providerof network connectivity for the US Department of Energy Office ofScience, the single largest supporter of basic research in the physicalsciences in the United States. In support of the Office of Scienceprograms, ESnet regularly updates and refreshes its understanding of thenetworking requirements of the instruments, facilities and scientiststhat it serves. This focus has helped ESnet to be a highly successfulenabler of scientific discovery for over 20 years. In August, 2002 theDOE Office of Science organized a workshop to characterize the networkingrequirements for Office of Science programs. Networking and middlewarerequirements were solicited from a representative group of scienceprograms. The workshop was summarized in two documents the workshop finalreport and a set of appendixes. This document updates the networkingrequirements for ESnet as put forward by the science programs listed inthe 2002 workshop report. In addition, three new programs have beenadded. Theinformation was gathered through interviews with knowledgeablescientists in each particular program or field

Passive tobacco exposure may impair symptomatic improvement in patients with chronic angina undergoing enhanced external counterpulsation

<p>Abstract</p> <p>Background</p> <p>The adverse effects of tobacco abuse on cardiovascular outcomes are well-known. However, the impact of passive smoke exposure on angina status and therapeutic response is less well-established. We examined the impact of second-hand smoke (SHS) exposure on symptomatic improvement in patients with chronic ischemic coronary disease undergoing enhanced external counterpulsation (EECP).</p> <p>Methods</p> <p>This observational study included 1,026 non-smokers (108 exposed and 918 not-exposed to SHS) from the Second International EECP Patient Registry. We also assessed angina response in 363 current smokers. Patient demographics, symptomatic improvement and quality of life assessment were determined by self-report prior and after EECP treatment.</p> <p>Results</p> <p>Non-smoking SHS subjects had a lower prevalence of prior revascularization (85% vs 90%), and had an increased prevalence of stroke (13% vs 7%) and prior smoking (72% vs 61%; all p < 0.05) compared to non-smokers without SHS exposure. Despite comparable degrees of coronary disease, baseline angina class, medical regimens and side effects during EECP, fewer SHS non-smokers completed a full 35-hour treatment course (77% vs 85%, p = 0.020) compared to non-smokers without SHS. Compared to non-smokers without SHS, non-smoking SHS subjects had less angina relief after EECP (angina class decreased ≥ 1 class: 68% vs 79%; p = 0.0082), both higher than that achieved in current smokers (66%). By multivariable logistic regression, SHS exposure was an independent predictor of failure to symptomatic improvement after EECP among non-smokers (OR 1.81, 95% confidence intervals 1.16–2.83).</p> <p>Conclusion</p> <p>Non-smokers with SHS exposure had an attenuated improvement in anginal symptoms compared to those without SHS following EECP.</p

Lessons Learned from a Decade of Sudden Oak Death in California: Evaluating Local Management

Sudden Oak Death has been impacting California’s coastal forests for more than a decade. In that time, and in the absence of a centrally organized and coordinated set of mandatory management actions for this disease in California’s wildlands and open spaces, many local communities have initiated their own management programs. We present five case studies to explore how local-level management has attempted to control this disease. From these case studies, we glean three lessons: connections count, scale matters, and building capacity is crucial. These lessons may help management, research, and education planning for future pest and disease outbreaks

Prevalence of Abnormalities in Vestibular Function and Balance among HIV-Seropositive and HIV-Seronegative Women and Men

BACKGROUND: Most HIV-seropositive subjects in western countries receive highly active antiretroviral therapy (HAART). Although many aspects of their health have been studied, little is known about their vestibular and balance function. The goals of this study were to determine the prevalences of vestibular and balance impairments among HIV-seropositive and comparable seronegative men and women and to determine if those groups differed. METHODS: Standard screening tests of vestibular and balance function, including head thrusts, Dix-Hallpike maneuvers, and Romberg balance tests on compliant foam were performed during semiannual study visits of participants who were enrolled in the Baltimore and Washington, D. C. sites of the Multicenter AIDS Cohort Study and the Women's Interagency HIV Study. RESULTS: No significant differences by HIV status were found on most tests, but HIV-seropositive subjects who were using HAART had a lower frequency of abnormal Dix-Hallpike nystagmus than HIV-seronegative subjects. A significant number of nonclassical Dix-Hallpike responses were found. Age was associated with Romberg scores on foam with eyes closed. Sex was not associated with any of the test scores. CONCLUSION: These findings suggest that HAART-treated HIV infection has no harmful association with vestibular function in community-dwelling, ambulatory men and women. The association with age was expected, but the lack of association with sex was unexpected. The presence of nonclassical Dix-Hallpike responses might be consistent with central nervous system lesions

Recent technological developments: In situ histopathological interrogation of surgical tissues and resection margins

Objectives: The tumour margin is an important surgical concept significantly affecting patient morbidity and mortality. We aimed in this prospective study to apply the microendoscope on tissue margins from patients undergoing surgery for oral cancer in vivo and ex vivo and compare it to the gold standard "paraffin wax", inter-observer agreement was measured; also to present the surgical pathologist with a practical guide to the every day use of the microendoscope both in the clinical and surgical fields. Materials and methods: Forty patients undergoing resection of oral squamous cell carcinoma were recruited. The surgical margin was first marked by the operator followed by microendoscopic assessment. Biopsies were taken from areas suggestive of close or positive margins after microendoscopic examination. These histological samples were later scrutinized formally and the resection margins revisited accordingly when necessary. Results: Using the microendoscope we report our experience in the determination of surgical margins at operation and later comparison with frozen section and paraffin section margins "gold standard". We were able to obtain a sensitivity of 95% and a specificity of 90%. Inter-observer Kappa scores comparing the microendoscope with formal histological analysis of normal and abnormal mucosa were 0.85. Conclusion: The advantage of this technique is that a large area of mucosa can be sampled and any histomorphological changes can be visualized in real time allowing the operator to make important informed decisions with regards the intra-operative resection margin at the time of the surgery

Patient-reported outcome measures in carotid artery revascularization: systematic review and psychometric analysis

Objective: Patient-reported outcome measures (PROMs) provide a way to measure the impact of a disease and its associated treatments on the quality of life from the patients’ perspective. The aim of this review was to identify PROMs that have been developed and/or validated in patients with carotid artery stenosis (CAS) undergoing revascularisation and to assess their psychometric properties and examine suitability for research and clinical use. Methods: Eight electronic databases including MEDLINE and CINAHL were searched using a two-stage search approach to identify studies reporting the development and/or validation of relevant PROMs in patients with CAS undergoing revascularisation. Supplementary citation searching and hand-searching reference lists of included studies were also undertaken. The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) and Oxford criteria were used to assess the methodological quality of the included studies and the psychometric properties of the PROMs were evaluated using established assessment criteria. Results: Five studies reporting on six PROMs were included: 36-Item Short Form Health Survey (SF-36), Euro-QoL-5-Dimension Scale (EQ-5D), Hospital Anxiety and Depression Scale (HADS), Dizziness Handicap Inventory (DHI), Quality of life for carotid artery disease scale and a disease-specific PROM for CAS. The rigour of the psychometric assessment of the PROMs was variable with most only attempting to assess a single psychometric criterion. No study reported evidence on construct validity and test-retest reliability. Evidence for acceptability for the use of SF-36, EQ-5D and the disease-specific PROM were rated good in most studies. Only one study reported a Cronbach alpha score >0.70 as evidence of internal consistency. Overall, the psychometric evaluation of all included PROMs was rated as poor within the CAS population undergoing revascularisation. Conclusions: This review highlighted a lack of evidence in validated PROMs used for patients undergoing carotid artery revascularisation. As a result, the development and validation of a new PROM for this patient population is warranted in order to provide data which can supplement traditional clinical outcomes (stroke<30 days post-procedural, myocardial infarction and death) and capture changes in health status and quality of life to help inform treatment decisions