1,248 research outputs found

    Development of a ‘Universal’ Rubric for Assessing Undergraduates’ Scientific Reasoning Skills Using Scientific Writing

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    We developed a rubric for measuring students’ ability to reason and write scientifically. The Rubric for Science Writing (Rubric) was tested in a variety of undergraduate biology laboratory courses (total n = 142 laboratory reports) using science graduate students (teaching assistants) as raters. Generalisability analysis indicates that the Rubric provides a reliable measure of students’ abilities (g = 0.85) in these conditions. Comparison of student performance in various biology classes indicated that some scientific skills are more challenging for students to develop than others and identified a number of previously unappreciated gaps in the curriculum. Our findings suggest that use of the Rubric provides three major benefits in higher education: (1) to increase substance and consistency of grading within a course, particularly those staffed by multiple instructors or graduate teaching assistants; (2) to assess student achievement of scientific reasoning and writing skills; and (3) when used in multiple courses, to highlight gaps in alignment among course assignments and provide a common metric for assessing to what extent the curriculum is achieving programmatic goals. Lastly, biology graduate students reported that use of the Rubric facilitated their teaching and recommended that training on the Rubric be provided to all teaching assistants

    A novel mode of capping protein-regulation by Twinfilin

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    Cellular actin assembly is controlled at the barbed ends of actin filaments, where capping protein (CP) limits polymerization. Twinfilin is a conserved in vivo binding partner of CP, yet the significance of this interaction has remained a mystery. Here, we discover that the C-terminal tail of Twinfilin harbors a CP-interacting (CPI) motif, identifying it as a novel CPI-motif protein. Twinfilin and the CPI-motif protein CARMIL have overlapping binding sites on CP. Further, Twinfilin binds competitively with CARMIL to CP, protecting CP from barbed-end displacement by CARMIL. Twinfilin also accelerates dissociation of the CP inhibitor V-1, restoring CP to an active capping state. Knockdowns of Twinfilin and CP each cause similar defects in cell morphology, and elevated Twinfilin expression rescues defects caused by CARMIL hyperactivity. Together, these observations define Twinfilin as the first \u27pro-capping\u27 ligand of CP and lead us to propose important revisions to our understanding of the CP regulatory cycle

    2013 Massachusetts Family Impact Seminar: Youth at Risk, Part 2

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    The youth of Massachusetts are of primary concern to legislators and citizens. This briefing report features three essays by experts — Fern Johnson, Deborah Frank, and Donna Haig Friedman — who focus on three aspects of children in need: children in foster care who need adoption, children who are hungry, and children who are homeless. Each report has further and more detailed suggestions for helping these children in need; below is a summary of the problems we face

    1% Calcium Chloride Treatment In Combination With Gamma Irradiation Improves Microbial and Physicochemical Properties Of Diced Tomatoes

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    The purpose of this study was to determine the effect of a combination of a 1% calcium chloride dip with low dose irradiation on microbial populations, and biochemical and physical properties, of fresh diced tomatoes during a two-week storage period. Vine tomatoes at the light-red stage (trial 1) and Celebrity tomatoes at the table ripe stage (trial 2) were diced, dipped in 1% CaCl2, and irradiated at 1 kGy from a Co-60 source. Tomatoes were also contaminated with cocktail of nalidixic-acid resistant Salmonella strains (S. Poona, S. Hartford, S. Gaminara, S. Michigan, and S. Montevideo) and subjected to gamma irradiation. Calcium treatment alone stimulated ethylene production in the diced tomatoes, whereas irradiation treatment alone suppressed ethylene production. The combination of calcium and irradiation treatments resulted in no change in ethylene production compared to the nontreated control, but respiration rate was suppressed by both irradiation and calcium treatment. The calcium dip was found to limit irradiation-induced loss of firmness. Irradiation, by itself and in combination with calcium treatment, resulted in a \u3e3 log CFU/g decrease in total aerobic counts and psychrotrophs. Additionally, irradiation at 1.5 kGy eliminated \u3e3 log CFU/g of Salmonella organisms from tomatoes contaminated with Salmonella. Counts continued to decrease to an undetectable level over the 11 day storage period. The results indicate that the combination of calcium treatment and irradiation can reduce the risk of disease due to pathogenic organisms such as Salmonella and can eliminate the problem of softening induced by irradiation

    Spectroscopic and Microscopic Investigation of the Corrosion of 316/316L Stainless Steel by Lead-Bismuth Eutectic (LBE) at Elevated Temperatures: Importance of Surface Preparation

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    The corrosion of steel by lead–bismuth eutectic (LBE) is an important issue in proposed nuclear transmutation schemes. Russian scientists at the IPPE exposed steel samples to oxygen-controlled LBE at temperatures up to 823 K and exposure times up to 3000 h. We have characterized these post-exposure steel samples and unexposed controls, using scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX) and X-ray photoelectron spectroscopy (XPS). Previous researchers have investigated the corrosion by LBE of steel of varying composition. In the present work, we compared two samples having the same composition (standard nuclear grade 316/316L) but different surface preparation: a cold-rolled sample was compared with an annealed sample. The cold-rolled sample had an order of magnitude less corrosion (i.e., both lower oxidation and less weight change) than the annealed sample. Sputter depth profiling of the exposed annealed sample and cold-rolled sample showed a marked difference in oxide layer composition between the annealed and cold-rolled samples. The annealed sample showed a complex oxide structure (iron oxide over chromium/iron oxide mixtures) of tens of microns thickness, while the cold-rolled sample was covered with a rather simple, primarily chromium oxide layer of ∌1 ÎŒm thickness

    Genetic parameters estimated at receiving for circulating cortisol, immunoglobulin G, interleukin 8, and incidence of bovine respiratory disease in feedlot beef steers

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    Citation: Cockrum, R. R., Speidel, S. E., Salak-Johnson, J. L., Chase, C. C. L., Peel, R. K., Weaber, R. L., . . . Enns, R. M. (2016). Genetic parameters estimated at receiving for circulating cortisol, immunoglobulin G, interleukin 8, and incidence of bovine respiratory disease in feedlot beef steers. Journal of Animal Science, 94(7), 2770-2778. doi:10.2527/jas2015-0222Bovine respiratory disease complex (i.e., shipping fever and bacterial bronchopneumonia) is a multifaceted respiratory illness influenced by numerous environmental factors and microorganisms. Bovine respiratory disease (BRD) is just one component of BRD complex. Because BRD is moderately heritable, it may be possible to reduce the incidence of BRD through genetic selection. The objectives of this study were to determine the heritability and associative genetic relationships among immune system traits (i.e., cortisol, total IgG, IgG isotypes, and IL-8) in cattle monitored for BRD incidence. At an average of 83 d after weaning (219 d age and mean = 221.7 kg [SD 4.34]), crossbred Bos taurus steer calves (n = 2,869) were received at a commercial feedlot in southeastern Colorado over a 2-yr period. At receiving, jugular blood samples were collected at 212 (yr 1) and 226 d (yr 2) of age for immune trait analyses. The BRD phenotype was defined as a binomial variable (0 = no and 1 = yes) and compared with immune system traits measured at receiving (prior to illness onset). An animal identified as BRD positive exhibited ? 2 clinical signs (i.e., eye or nasal discharge, cough, lethargy, rapid breathing, acute interstitial pneumonia, or acute upper respiratory syndrome and/or a rectal temperature > 39.7°C). Heritability and genetic correlation estimates for categorical variable BRD, cortisol, IgG, IgG1, IgG2, and IL-8 were estimated from a sire model using ASREML. Heritability estimates were low to moderate for BRD (0.17 ± 0.08), cortisol (0.13 ± 0.05), IgG (0.15 ± 0.05), IgG1 (0.11 ± 0.05), IgG2 (0.24 ± 0.06), and IL-8 (0.30 ± 0.06). A moderate negative genetic correlation was determined between BRD and cortisol (rg = ?0.19 ± 0.32). Moderate positive correlations were found between BRD with IgG (0.42 ± 0.28), IgG1 (0.36 ± 0.32), and IL-8 (rg = 0.26 ± 0.26). Variation in the BRD phenotype and immune system traits suggested herd health improvement may be achieved through genetic selection. © 2016 American Society of Animal Science. All rights reserved

    Geographic Differences in Time to Culture Conversion in Liquid Media: Tuberculosis Trials Consortium Study 28. Culture Conversion Is Delayed in Africa

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    Tuberculosis Trials Consortium Study 28, was a double blind, randomized, placebo-controlled, phase 2 clinical trial examining smear positive pulmonary Mycobacterium tuberculosis. Over the course of intensive phase therapy, patients from African sites had substantially delayed and lower rates of culture conversion to negative in liquid media compared to non-African patients. We explored potential explanations of this finding.In TBTC Study 28, protocol-correct patients (n = 328) provided spot sputum specimens for M. tuberculosis culture in liquid media, at baseline and weeks 2, 4, 6 and 8 of study therapy. We compared sputum culture conversion for African and non-African patients stratified by four baseline measures of disease severity: AFB smear quantification, extent of disease on chest radiograph, cavity size and the number of days to detection of M. tuberculosis in liquid media using the Kaplan-Meier product-limit method. We evaluated specimen processing and culture procedures used at 29 study laboratories serving 27 sites.African TB patients had more extensive disease at enrollment than non-African patients. However, African patients with the least disease by the 4 measures of disease severity had conversion rates on liquid media that were substantially lower than conversion rates in non-African patients with the greatest extent of disease. HIV infection, smoking and diabetes did not explain delayed conversion in Africa. Some inter-site variation in laboratory processing and culture procedures within accepted practice for clinical diagnostic laboratories was found.Compared with patients from non-African sites, African patients being treated for TB had delayed sputum culture conversion and lower sputum conversion rates in liquid media that were not explained by baseline severity of disease, HIV status, age, smoking, diabetes or race. Further investigation is warranted into whether modest variation in laboratory processes substantially influences the efficacy outcomes of phase 2 TB treatment trials or if other factors (e.g., nutrition, host response) are involved.ClinicalTrials.gov NCT00144417

    Genetic analysis of a rabies virus host shift event reveals within-host viral dynamics in a new host

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    Host shift events play an important role in epizootics as adaptation to new hosts can profoundly affect the spread of the disease and the measures needed to control it. During the late 1990s, an epizootic in Turkey resulted in a sustained maintenance of rabies virus (RABV) within the fox population. We used Bayesian inferences to investigate whole genome sequences from fox and dog brain tissues from Turkey to demonstrate that the epizootic occurred in 1997 (±1 year). Furthermore, these data indicated that the epizootic was most likely due to a host shift from locally infected domestic dogs, rather than an incursion of a novel fox or dog RABV. No evidence was observed for genetic adaptation to foxes at consensus sequence level and dN/dS analysis suggested purifying selection. Therefore, the deep sequence data were analysed to investigate the sub-viral population during a host shift event. Viral heterogeneity was measured in all RABV samples; viruses from the early period after the host shift exhibited greater sequence variation in comparison to those from the later stage, and to those not involved in the host shift event, possibly indicating a role in establishing transmission within a new host. The transient increase in variation observed in the new host species may represent virus replication within a new environment, perhaps due to increased replication within the CNS, resulting in a larger population of viruses, or due to the lack of host constraints present in the new host reservoir

    Disclosing genetic risk for Alzheimer’s dementia to individuals with mild cognitive impairment

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    IntroductionThe safety of predicting conversion from mild cognitive impairment (MCI) to Alzheimer’s disease (AD) dementia using apolipoprotein E (APOE) genotyping is unknown.MethodsWe randomized 114 individuals with MCI to receive estimates of 3‐year risk of conversion to AD dementia informed by APOE genotyping (disclosure arm) or not (non‐disclosure arm) in a non‐inferiority clinical trial. Primary outcomes were anxiety and depression scores. Secondary outcomes included other psychological measures.ResultsUpper confidence limits for randomization arm differences were 2.3 on the State Trait Anxiety Index and 0.5 on the Geriatric Depression Scale, below non‐inferiority margins of 3.3 and 1.0. Moreover, mean scores were lower in the disclosure arm than non‐disclosure arm for test‐related positive impact (difference: ‐1.9, indicating more positive feelings) and AD concern (difference: ‐0.3).DiscussionProviding genetic information to individuals with MCI about imminent risk for AD does not increase risks of anxiety or depression and may provide psychological benefits.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154645/1/trc212002_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154645/2/trc212002.pd
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