Infection frequently triggers thrombotic microangiopathy in patients with preexisting risk factors : a single-institution experience

Thrombotic microangiopathies are rare conditions characterized by microangiopathic hemolytic anemia, microthrombi, and multiorgan insult. The disorders, which include hemolytic uremic syndrome and thrombotic thrombocytopenic purpura, are often acute and life threatening. We report a retrospective analysis of 65 patients presenting to our institution from 1997 to 2008 with all forms of thrombotic microangiopathy. Therapeutic plasma exchange was a requirement for analysis and 65 patients were referred to our institution; 66% of patients were female and median age at presentation was 52 years. Bacterial infection was the most commonly identified etiologic factor and in the multivariate model was the only significant variable associated with survival outcome (odds ratio 5.1, 95% confidence interval, 1.2-21.7). As infection can be considered a common trigger event for thrombotic microangiopathy, patients with hepatobiliary sepsis may benefit from elective cholecystectomy. We conclude that bacterial infection frequently triggers TTP and other thrombotic microangiopathies in patients with preexisting risk factors and propose a model for the development of these syndromes

Systematic Errors in Stereo PIV When Imaging through a Glass Window

This document assesses the magnitude of velocity measurement errors that may arise when performing stereo particle image velocimetry (PIV) with cameras viewing through thick, refractive window and where the calibration is performed in one plane only. The effect of the window is to introduce a refractive error that increases with window thickness and the camera angle of incidence. The calibration should be performed while viewing through the test section window, otherwise a potentially significant error may be introduced that affects each velocity component differently. However, even when the calibration is performed correctly, another error may arise during the stereo reconstruction if the perspective angle determined for each camera does not account for the displacement of the light rays as they refract through the thick window. Care should be exercised when applying in a single-plane calibration since certain implicit assumptions may in fact require conditions that are extremely difficult to meet in a practical laboratory environment. It is suggested that the effort expended to ensure this accuracy may be better expended in performing a more lengthy volumetric calibration procedure, which does not rely upon the assumptions implicit in the single plane method and avoids the need for the perspective angle to be calculated

Algal Growth Potentials and Heavy Metal Concentrations of the Primary Streams to Upper Beaver Lake

Meyer and Green (1984) demonstrated the probable inhibition of algal growth potential by heavy metals in upper Beaver Lake. Upper Beaver Lake receives water from three tributaries. One contains a small reservoir and the combined streams receive sewage input. Collections were made approximately monthly at eight sites for the Algal Assay Bottle Test (AABT) and heavy metal analysis. In general, AABT results indicated that the collections above the sewage lnput were phosphorus limited while those below were nitrogen or combined nitrogen and phosphorus limited. Growth inhibition occurred during summer and early fall at various sites with greater inhibition at the confluence of the streams. No inhibitions occurred, at the site below the sewage input. Heavy metal concentrations had an overall tendency to increase downstream. Values within the small reservoir were 50-100% higher than in the feeder stream. Highest values of Pb were observed below the reservoir. SO4 ,Cl, Mg, Ca, Na and K had high values during low flow in August-ctober. The low values were independent of high flow. Pb followed an independent pattern. Storm event results showed that the Ca maximum was before the hydrographic peak while Fe, Mn, Pb, In, Co, Ni, Cu and Cd attained their maximum just after the peak. Maximum values were 4-10 times background values. Mn, Pb and Fe exceeded EPA recommended standards for drinking water

The power of the middle bit of a #P function

Peer Reviewe

Upending the Social Ecological Model to Guide Health Promotion Efforts Toward Policy and Environmental Change

Efforts to change policies and the environments in which people live, work, and play have gained increasing attention over the past several decades. Yet health promotion frameworks that illustrate the complex processes that produce health-enhancing structural changes are limited. Building on the experiences of health educators, community activists, and community-based researchers described in this supplement and elsewhere, as well as several political, social, and behavioral science theories, we propose a new framework to organize our thinking about producing policy, environmental, and other structural changes. We build on the social ecological model, a framework widely employed in public health research and practice, by turning it inside out, placing health-related and other social policies and environments at the center, and conceptualizing the ways in which individuals, their social networks, and organized groups produce a community context that fosters healthy policy and environmental development. We conclude by describing how health promotion practitioners and researchers can foster structural change by (1) conveying the health and social relevance of policy and environmental change initiatives, (2) building partnerships to support them, and (3) promoting more equitable distributions of the resources necessary for people to meet their daily needs, control their lives, and freely participate in the public sphere

Cortical and subcortical coordination of visual spatial attention revealed by simultaneous EEG-fMRI recording

Visual spatial attention has been studied in humans with both electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) individually. However, due to the intrinsic limitations of each of these methods used alone, our understanding of the systems-level mechanisms underlying attentional control remains limited. Here, we examined trial-to-trial covariations of concurrently recorded EEG and fMRI in a cued visual spatial attention task in humans, which allowed delineation of both the generators and modulators of the cue-triggered event-related oscillatory brain activity underlying attentional control function. The fMRI activity in visual cortical regions contralateral to the cued direction of attention covaried positively with occipital gamma-band EEG, consistent with activation of cortical regions representing attended locations in space. In contrast, fMRI activity in ipsilateral visual cortical regions covaried inversely with occipital alpha-band oscillations, consistent with attention-related suppression of the irrelevant hemispace. Moreover, the pulvinar nucleus of the thalamus covaried with both of these spatially specific, attention-related, oscillatory EEG modulations. Because the pulvinar's neuroanatomical geometry makes it unlikely to be a direct generator of the scalp-recorded EEG, these covariational patterns appear to reflect the pulvinar's role as a regulatory control structure, sending spatially specific signals to modulate visual cortex excitability proactively. Together, these combined EEG/fMRI results illuminate the dynamically interacting cortical and subcortical processes underlying spatial attention, providing important insight not realizable using either method alone

Spectroscopic Characterization of Oceanic Dissolved Organic Matter Isolated By Reverse Osmosis Coupled With Electrodialysis

Oceanic dissolved organic matter (DOM) is one of the largest pools of reduced carbon on Earth, yet DOM remains poorly chemically characterized. Studies to determine the chemical nature of oceanic DOM have been impeded by the lack of efficient and non-fractioning methods to recover oceanic DOM. Here, a DOM fraction (~40 to 86% recovery) was isolated using reverse osmosis/electrodialysis (RO/ED) and analyzed by solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Samples were obtained from biogeochemically distinct environments: photobleached surface gyre, productive coastal upwelling zone, oxygen minimum, North Atlantic Deep Water, and North Pacific Deep Water. A ubiquitous ‘background’ refractory carbon pool was apparent throughout the ocean and dominated in the deep Pacific Ocean. Advanced NMR spectral editing revealed that condensed aromatic and quaternary anomeric carbons contribute to this deep refractory DOC pool, the quaternary anomeric carbons being a newly identified and potentially important component of bio-refractory carbohydrate-like carbon. Additionally, our results support the multi-pool (e.g. 3-pool: labile, semi-labile, and refractory) conceptual model of marine DOM biogeochemistry. Surface samples, hypothesized to be enriched in labile and semi-labile DOM, were enriched in carbohydrate-like material consistent with prior studies. High carboxyl signals in the deep Pacific support the hypothesis that a major fraction of the refractory pool consists of carboxyl-rich alicyclic molecules (CRAM)

Spacecraft Charging Test Considerations for Composite Materials

Composite materials present a growing challenge for spacecraft charging assessments. We review some recent lessons learned for charging tests of composite materials using both parallel-plate and electron beam test geometries. We also discuss examples of materials that exhibit significant variations between samples, despite them all having the same trade name