Verification of the ASTM G-124 Purge Equation

ASTM G-124 seeks to evaluate combustion characteristics of metals in high-purity (greater than 99%) oxygen atmospheres. ASTM G-124 provides the following equation to determine the minimum number of purges required to reach this level of purity in a test chamber: n = -4/log10(Pa/Ph), where "n" is the total number of purge cycles required, Ph is the absolute pressure used for the purge on each cycle and Pa is the atmospheric pressure or the vent pressure. The origin of this equation is not known and has been the source of frequent questions as to its accuracy and reliability. This paper shows the derivation of the G-124 purge equation, and experimentally explores the equation to determine if it accurately predicts the number of cycles required

Back-electron transfer suppresses the periodic length dependence of DNA-mediated charge transport across adenine tracts

DNA-mediated charge transport (CT) is exquisitely sensitive to the integrity of the bridging π-stack and is characterized by a shallow distance dependence. These properties are obscured by poor coupling between the donor/acceptor pair and the DNA bridge, or by convolution with other processes. Previously, we found a surprising periodic length dependence for the rate of DNA-mediated CT across adenine tracts monitored by 2-aminopurine fluorescence. Here we report a similar periodicity by monitoring N2-cyclopropylguanosine decomposition by rhodium and anthraquinone photooxidants. Furthermore, we find that this periodicity is attenuated by consequent back-electron transfer (BET), as observed by direct comparison between sequences that allow and suppress BET. Thus, the periodicity can be controlled by engineering the extent of BET across the bridge. The periodic length dependence is not consistent with a periodicity predicted by molecular wire theory but is consistent with a model where multiples of four to five base pairs form an ideal CT-active length of a bridging adenine domain

Closing the Divide: How Medical Homes Promote Equity in Health Care

Presents findings from the Commonwealth Fund 2006 Health Care Quality Survey, and demonstrates how having stable insurance, a regular provider and, in particular, a medical home, improves health care access and quality among vulnerable populations

Identifying New England’s underutilized seafood species and evaluating their market potential in a changing climate

Developing and diversifying market opportunities for lesser known yet abundant seafood species has been a successful strategy for seafood businesses in the Northeast United States. Since climate change and other stressors are currently threatening the economic vitality of New England’s seafood industry, it is important to identify if there are lesser-known species that could simultaneously support additional market opportunities and remain resilient in a warming climate. We developed a quantitative definition for the term “underutilized species’’ based on five criteria derived from science-based sustainable fishing metrics. Using this definition, we evaluated 47 stocks in the Northeast United States during the initial time period of 2013-2017 to identify seven underutilized finfish species that could be considered for new market opportunities as part of a climate-smart approach: 1) Acadian redfish (Sebastes fasciatus), 2) Atlantic pollock (Pollachius virens), 3) butterfish (Peprilus triacanthus), 4) haddock (Melanogrammus aeglefinus), 5) scup (Stenotomus chrysops), 6) silver hake (Merluccius bilinearis), and 7) white hake (Urophycis tenuis). The climate resiliency of these resulting seven species was then evaluated using a framework consisting of species-specific metrics on climate sensitivity, directionality (of responses to climate impacts) and future habitat availability under warming scenarios. Our results show that assessing underutilized species on a regular basis and evaluating their ongoing responses to climate change can be a part of a climate-smart approach towards building more diversified and adaptive markets

The imprint of strong-storm tracks on winter weather in North America

Northern Hemisphere winter storm tracks and their relation to winter weather are investigated using CFSR data. Storm tracks are described by isentropic PV maxima within a Lagrangian framework; these correspond well with those described in previous studies. Our diagnostics focus on strong-storm tracks, which are comprised of storms that achieve a maximum PV exceeding the mean value by one standard deviation. Large increases in diabatic heating related to deep convection occur where the storm tracks are most intense. The cyclogenesis pattern shows that strong storms generally develop on the upstream sectors of the tracks. Intensification happens towards the eastern North Pacific and all across the North Atlantic Ocean, where enhanced storm track-related weather is found. In this study, the relation of storm tracks to near-surface winds and precipitation is evaluated. The largest increases in storm track-related winds are found where strong storms tend to develop and intensify, while storm precipitation is enhanced in areas where the storm tracks have the highest intensity. Strong storms represent about 16% of all storms but contribute 30-50% of the storm precipitation in the storm track regions. Both strong-storm related winds and precipitation are prone to cause storm-related losses in the eastern US and North American coasts. Over the oceans, maritime operations are expected to be most vulnerable to damage offshore of the US coasts. Despite making up a small fraction of all storms, the strong-storm tracks have a significant imprint on winter weather in North America potentially leading to structural and economic loss

Relation between Sexual and Gender Minority Status and Suicide Attempts Among Veterans Seeking Treatment for Military Sexual Trauma

There is limited study of suicidal behaviors among veterans identifying as sexual and gender minorities (SGMs), despite previous research indicating rates of suicide attempts are high within civilian SGM populations. Further, some research incorporating military service members suggests those identifying as SGMs are disproportionately exposed to military sexual trauma (MST), an additional risk factor for negative psychiatric sequelae. To address health care research disparities among minority veterans (i.e., women, those endorsing MST, SGMs), we examined presentations of veterans (N = 277) who attended initial consultation appointments for MST-related treatment and completed a semistructured clinical interview including demographic characteristics, history of suicide attempts (HSA), and a diagnostic evaluation. Twenty-eight (10.1%) veterans identified as SGMs. SGM/non-SGM groups were contrasted on suicidal and psychiatric morbidity outcomes. Overall, endorsement of HSA was high (30.7%). Despite similar clinical profiles, 53.6% of veterans who identified as SGM endorsed HSA in contrast with 28.1% of peers identifying as heterosexual and nontransgender, a significant effect of small-to-moderate size. Findings suggest assessment and clinical management of suicidality is of critical importance for clinicians providing services to veterans pursuing recovery from MST, generally, and may be especially so when delivering care to SGM. Further, results underscore the need for culturally competent delivery of trauma-focused interventions

Dynamic adjustment of the ocean circulation to self-attraction and loading effects

The oceanic response to surface loading, such as that related to atmospheric pressure, freshwater exchange, and changes in the gravity field, is essential to our understanding of sea level variability. In particular, so-called self-attraction and loading (SAL) effects caused by the redistribution of mass within the land–atmosphere–ocean system can have a measurable impact on sea level. In this study, the nature of SAL-induced variability in sea level is examined in terms of its equilibrium (static) and nonequilibrium (dynamic) components, using a general circulation model that implicitly includes the physics of SAL. The additional SAL forcing is derived by decomposing ocean mass anomalies into spherical harmonics and then applying Love numbers to infer associated crustal displacements and gravitational shifts. This implementation of SAL physics incurs only a relatively small computational cost. Effects of SAL on sea level amount to about 10% of the applied surface loading on average but depend strongly on location. The dynamic component exhibits large-scale basinwide patterns, with considerable contributions from subweekly time scales. Departures from equilibrium decrease toward longer time scales but are not totally negligible in many places. Ocean modeling studies should benefit from using a dynamical implementation of SAL as used here

Restoration of Vision with Ectopic Expression of Human Rod Opsin

SummaryMany retinal dystrophies result in photoreceptor loss, but the inner retinal neurons can survive, making them potentially amenable to emerging optogenetic therapies. Here, we show that ectopically expressed human rod opsin, driven by either a non-selective or ON-bipolar cell-specific promoter, can function outside native photoreceptors and restore visual function in a mouse model of advanced retinal degeneration. Electrophysiological recordings from retinal explants and the visual thalamus revealed changes in firing (increases and decreases) induced by simple light pulses, luminance increases, and naturalistic movies in treated mice. These responses could be elicited at light intensities within the physiological range and substantially below those required by other optogenetic strategies. Mice with rod opsin expression driven by the ON-bipolar specific promoter displayed behavioral responses to increases in luminance, flicker, coarse spatial patterns, and elements of a natural movie at levels of contrast and illuminance (≈50–100 lux) typical of natural indoor environments. These data reveal that virally mediated ectopic expression of human rod opsin can restore vision under natural viewing conditions and at moderate light intensities. Given the inherent advantages in employing a human protein, the simplicity of this intervention, and the quality of vision restored, we suggest that rod opsin merits consideration as an optogenetic actuator for treating patients with advanced retinal degeneration