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DavidsonAllysonChemBioEnvironEnginToxicityMinimizedCryoprotectant.pdf
No full textIce-free cryopreservation, known as vitrification, is an appealing approach for banking of adherent cells and tissues because it prevents dissociation and morphological damage that may result from ice crystal formation. However, current vitrification methods are often limited by the cytotoxicity of the concentrated cryoprotective agent (CPA) solutions that are required to suppress ice formation. Recently, we described a mathematical strategy for identifying minimally toxic CPA equilibration procedures based on the minimization of a toxicity cost function. Here we provide direct experimental support for the feasibility of these methods when applied to adherent endothelial cells. We first developed a concentration- and temperature-dependent toxicity cost function by exposing the cells to a range of glycerol concentrations at 21°C and 37°C, and fitting the resulting viability data to a first order cell death model. This cost function was then numerically minimized in our state constrained optimization routine to determine addition and removal procedures for 17 molal (mol/kg water) glycerol solutions. Using these predicted optimal procedures, we obtained 81% recovery after exposure to vitrification solutions, as well as successful vitrification with the relatively slow cooling and warming rates of 50°C/min and 130°C/min. In comparison, conventional multistep CPA equilibration procedures resulted in much lower cell yields of about 10%. Our results demonstrate the potential for rational design of minimally toxic vitrification procedures and pave the way for extension of our optimization approach to other adherent cell types as well as more complex systems such as tissues and organs
Inclusive Production of the X(4140) State in pp̄ Collisions at D0
Get PDFSee article for Abstract.This is the publisher’s final pdf. The published article is copyrighted by the American Physical Society and can be found at: http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.115.23200
HagertyCBotanyPlantPathMappingFusariumSolani.pdf
No full textRoot rot diseases of bean (Phaseolus vulgaris L.) are a constraint to dry and snap bean production. We developed the RR138 RI mapping population from the cross of OSU5446, a susceptible line that meets current snap bean processing industry standards, and RR6950, a root rot resistant dry bean with small brown seeds. We evaluated the RR138 RI population beginning in the F₆ generation for resistance to Fusarium solani f. sp. phaseoli (Burk.) root rot in Oregon and Aphanomyces euteiches (Drechsler) root rot in Wisconsin. The population was evaluated for a set of root architecture traits at the Oregon location. Fusarium solani root rot resistance was evaluated in three seasons, whereas A. euteiches resistance was evaluated in two seasons. For each disease, RR6950 was resistant and OSU 5446 was susceptible. The recombinant inbred (RI) population was normally distributed for reaction to both diseases. We assembled a high-density linkage map using 1689 single-nucleotide polymorphisms (SNPs) from an Illumina 6000-SNP BARCbean6K_3 Beadchip. The map spanned 1196 cM over 11 linkage groups at a density of one SNP per 1.4 cM. Three quantitative trait loci (QTL) associated with A. euteiches were identified, each accounting for 5 to 15% of the total genetic variation, and two QTL associated with F. solani resistance accounted for 9 and 22% of the total genetic variation. A QTL for taproot diameter (TD) and one QTL for basal root angle were identified. The QTL for resistance to the two diseases mapped to different genome locations indicating a different genetic control
Patterns of Shelter Use Among Men New to Homelessness in Later Life: Duration of Stay and Psychosocial Factors Related to Departure
No full textPeople who become homeless for the first time in late life are a growing but understudied population. This study draws on administrative data from one shelter (N = 1,214 first-time homeless) to assess the extent to which age is related to shelter stay and, to examine psychosocial factors that may be associated with shelter departure. Our bivariate and survival analysis results suggest that older homeless men stay in the shelter 2 weeks longer than younger clients. Older men with pending legal issues and mobility concerns were more likely to leave the shelter than those without such concerns. Findings highlight the impact of age and other psychosocial variables on shelter stay, and provide direction from which to address homelessness among men who are new to homelessness in later life
BurnsPatCEOASPredictingGlacioHydrolicChange.pdf
No full textIn many partially glacierized watersheds glacier recession driven by a warming climate could lead to complex patterns of streamflow response over time, often marked with rapid increases followed by sharp declines, depending on initial glacier ice cover and rate of climate change. Capturing such “phases” of hydrologic response is critical in regions where communities rely on glacier meltwater, particularly during low flows. In this paper, we investigate glacio-hydrologic response in the headwaters of the Zongo River, Bolivia, under climate change using a distributed glacio-hydrological model over the period of 1987–2100. Model predictions are evaluated through comparisons with satellite-derived glacier extent estimates, glacier surface velocity, in situ glacier mass balance, surface energy flux, and stream discharge measurements. Historically (1987–2010) modeled glacier melt accounts for 27% of annual runoff, and 61% of dry season (JJA) runoff on average. During this period the relative glacier cover was observed to decline from 35 to 21% of the watershed. In the future, annual and dry season discharge is projected to decrease by 4% and 27% by midcentury and 25% and 57% by the end of the century, respectively, following the loss of 81% of the ice in the watershed. Modeled runoff patterns evolve through the interplay of positive and negative trends in glacier melt and increased evapotranspiration as the climate warms. Sensitivity analyses demonstrate that the selection of model surface energy balance parameters greatly influences the trajectory of hydrological change projected during the first half of the 21st century. These model results underscore the importance of coupled glacio-hydrology modeling
Oxygen isotope measurements of seawater (H₂¹⁸)O/H₂¹⁶O): A comparison of cavity ring-down spectroscopy (CRDS) and isotope ratio mass spectrometry (IRMS)
No full textLaser-based spectroscopic techniques, such as cavity ring-down spectroscopy (CRDS), provide a new, cost effective and more widely available approach to measure the oxygen isotope ratio in water molecules, H₂¹⁸O/H₂¹⁶O (δ¹⁸O), and are used increasingly to measure δ¹⁸O in the world's oceans. Here, we present results from an interlaboratory comparison designed to evaluate the quality of CRDS-derived measurements, and their consistency with values measured by isotope ratio mass spectrometry (IRMS). We also discuss the influence of salt on instrument performance and sample throughput for the analysis of seawater samples. This study compared measurements of δ¹⁸O from natural samples with a wide range of salinities (0, 29.4, and 34.6) performed by four independent labs: two using CRDS and two using IRMS. We also compared δ¹⁸O measurements of Northeast Atlantic Deep Water collected in 2013, 2012, 2009, and 1995 from the AR7W repeat hydrography transect across the Labrador Sea. The within-lab precision of ocean-based CRDS measurements is seen to approach 0.03‰, which is better than the manufacturer's typically stated analytical precision (around +/− 0.05‰), and comparable to that achievable with IRMS. The interlaboratory differences of measurements (highest-lowest) reported by the four labs is taken as an indicator of overall accuracy, and is estimated conservatively as being < 0.1‰, with the potential to approach 0.05‰. Overall, these results show that CRDS based ¹⁸O measurements of seawater can be equivalent to high-quality measurements by IRMS.This is the publisher’s final pdf. The published article is copyrighted by the Association for the Sciences of Limnology and Oceanography and can be found at: http://www.aslo.org/lomethods/index.htm
Targeting an Essential GTPase Obg for the Development of Broad-Spectrum Antibiotics
Get PDFA promising new drug target for the development of novel broad-spectrum antibiotics is the highly conserved small GTPase Obg (YhbZ, CgtA), a protein essential for the survival of all bacteria including Neisseria gonorrhoeae (GC). GC is the agent of gonorrhea, a prevalent sexually transmitted disease resulting in serious consequences on reproductive and neonatal health. A preventive anti-gonorrhea vaccine does not exist, and options for effective antibiotic treatments are increasingly limited. To address the dire need for alternative antimicrobial strategies, we have designed and optimized a 384-well GTPase assay to identify inhibitors of Obg using as a model Obg protein from GC, Obg[subscript]GC. The assay was validated with a pilot screen of 40,000 compounds and achieved an average Z’ value of 0.58 ± 0.02, which suggests a robust assay amenable to high-throughput screening. We developed secondary assessments for identified lead compounds that utilize the interaction between Obg[subscript]GC and fluorescent guanine nucleotide analogs, mant-GTP and mant-GDP, and an Obg[subscript]GC variant with multiple alterations in the G-domains that prevent nucleotide binding. To evaluate the broad-spectrum potential of Obg[subscript]GC inhibitors, Obg proteins of Klebsiella pneumoniae and methicillin-resistant Staphylococcus aureus were assessed using the colorimetric and fluorescence-based activity assays. These approaches can be useful in identifying broad-spectrum Obg inhibitors and advancing the therapeutic battle against multidrug resistant bacteri
Large enhancement of nonlinear terahertz absorption in intrinsic GaAs by plasmonic nano antennas
Get PDFWe demonstrate remarkably strong nonlinear terahertz (THz) effects in an intrinsic GaAs wafer patterned with a nanometer-width slot antenna array. The antenna near-field reaches 20 MV/cm due to the huge field enhancement in the plasmonic nano-structure (field enhancement factor, α ≅ 50). The THz fields are strong enough to generate high density free carriers (Nₑ > 10¹⁷ cm⁻³) via interband excitations associated with impact ionizations and thus to induce large absorption of the THz radiation (>35%). The nonlinear THz interactions take place in the confined region of nanometer-scale layer adjacent to the antenna.This is the publisher’s final pdf. The published article is copyrighted by the American Institute of Physics Publishing and can be found at: http://scitation.aip.org/content/aip/journal/apl
MeintsDevelopingWinterFoodBarleyFigure3.pdf
No full textBarley (Hordeum vulgare L.) has been cultivated for human consumption for thousands of years. However, most North Americans do not consume barley on a regular basis. In the last decade, there has been a renewed interest in barley production for human consumption. A number of quality traits estimate nutritional value and are useful for food processing. These include β-glucan, grain protein, kernel hardness, solvent retention capacity (SRC), and hull type. The Pacific Northwest (PNW) of the US is a high-yielding region that has a reputation for setting dietary and nutritional trends. However, there are currently no winter food barleys adapted to this area. To determine the potential suitability of winter growth habit for food barley production in the PNW, we developed and tested 14 advanced lines. The germplasm was developed via marker-assisted and phenotypic selection and included hulled lines with waxy starch and hull-less lines with normal starch. Agronomic and food quality traits were measured on samples from three representative environments (dryland, irrigated, and high rainfall) over a two-year period allowing for assessment of performance within and across locations, as well as genotype x environment interaction. Lines with waxy starch had significantly higher levels of β-glucan, harder kernels, and higher water retention capacity. Hull-less lines had, on average, slightly lower yields than hulled lines with the average difference of 105 kg ha⁻¹. Our future food barley variety development will focus exclusively on hull-less types, due to the simplified processing and consumer interest in the nutritional benefits of whole grain
Designing Media for Visually-Impaired Users of Refreshable Touch Displays: Possibilities and Pitfalls
Get PDFThis paper discusses issues of importance to designers of media for visually impaired users. The paper considers the influence of human factors on effectiveness of presentation as well as the strengths and weaknesses of tactile, vibrotactile, static pins, haptic, force feedback, and multimodal methods of rendering maps, graphs and models. The authors, all of whom are visually-impaired researchers in this domain, present findings from their own work and work of many others who have contributed to the current understanding of how to prepare and render images for both hard-copy and technology-mediated presentation of Braille and tangible graphics.©2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works