2,545 research outputs found

    NSF Graduate Teaching Fellows in K-12 Education at the University of Maine

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    The program for Graduate Teaching Fellows in K-12 Education at the University of Maine is consistent with the State\u27s legislatively mandated goals for education in Science and Technology. Twelve Fellows are working in four local school districts through this program, which engages colleagues at the University and K-12 schools in transfer of knowledge and curriculum development with respect to topics such as Classifying Living Things, Forestry & Pulp and Paper Studies, and The Hydrological Cycle. The project is providing K-12 students and teachers with access to curriculum development, field trips, technology, and equipment that local school budgets had not provided. A summer science camp is being used in the training program to establish the teaching teams (university faculty and K-12 teachers) that mentor Fellows. The program provides SMET fellowships for the University, professional development for K-12 teachers, important role models and knowledge to K-12 students, and a strong bond between the science faculty of the University and K-12 teachers

    GK-12: NSF Graduate Teaching Fellows in K-12 Education at the University of Maine

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    Eight districts in central Maine that comprise the Penobscot River Educational Partnership (PREP); four of them, including Maine Indian Education, partners in a current GK-12 project, have joined with the University of Maine to form Fellow-teacher teams to introduce K-12 students to experiments, field trips, and discussions in areas such as chemistry, climate change, marine sciences, molecular biology, geology, food sciences, and ecology. The program is: a) helping teachers and students reach the State of Maine\u27s legislatively-mandated standards for Science & Technology (the Maine Learning Results), b) strengthening Fellows\u27 communication and teaching skills, c) providing professional development for Teachers, d) enriching science for K-12 students, e) providing young male and female role models of SMET professionals to children in grades 3-11, and f) strengthening contacts between GK-12 science faculty and K-12 districts. The K-12 students are monitoring water chemistry and species diversity and abundance in cooperating federal wildlife refuges in areas near them. These shared monitoring activities link classes throughout the entire scope of the project. The spatially and temporally distributed data enables the teams to introduce interesting analyses and discussions across partner classes interacting through videoconferences. Each Fellow works intensively with two teachers in PREP and with a teacher from eastern Maine (Washington & Hancock Counties), western Maine (Madison), or southern Maine (Damariscotta, site of the University of Maine\u27s marine sciences laboratory). The power of Maine\u27s network of ATM classrooms, is being used to expand the Fellows\u27 role modeling and introduce Fellows to a variety of teaching styles. The broader impacts of the project include strengthened backgrounds in science and attendance at the Maine summer Science Camp for the cooperating teachers. The K-12 districts\u27 benefits include the enriched learning of their students and access to the equipment from microscopes to thermal cyclers that is necessary to meet the goals of the Learning Results, but which many districts lack. The University of Maine is benefiting from K-12 students who come to the University better prepared in science and is fulfilling its mission as a Land Grant/Sea Grant institution to serve both the state of Maine and the nation as a whole

    Botulism from Drinking Pruno

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    Foodborne botulism occurred among inmates at 2 prisons in California in 2004 and 2005. In the first outbreak, 4 inmates were hospitalized, 2 of whom required intubation. In the second event, 1 inmate required intubation. Pruno, an alcoholic drink made illicitly in prisons, was the novel vehicle for these cases

    Determination of selenium in serum in the presence of gadolinium with ICP-QQQ-MS

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    Gadolinium (Gd)-based magnetic resonance imaging (MRI) contrasting agents interfere with the determination of selenium (Se) when analysed by single quadrupole inductively coupled plasma-mass spectrometry (ICP-MS). This paper demonstrates that an ICP-triple quadrupole-MS (ICP-QQQ-MS) with oxygen mass shift overcomes Gd++ interference on Se+ and mitigates typically encountered matrix and spectral based interferences. Normal human serum was diluted in a solution containing isopropanol, EDTA, NH4OH and Triton X-100. Samples were unspiked (control) serum; serum spiked with 0.127 μmol L−1 Se or 127 μmol L−1 Gd; and serum spiked with both 0.127 μmol L−1 Se and 127 μmol L−1 Gd. Consideration of collision/reaction gases and conditions for interference mitigation included helium (He); a ‘low’ and ‘high’ hydrogen (H2) flow, and oxygen (O2). The instrument tune for O2 was optimised for effective elimination of interferences via a mass shift reaction of Se+ to SeO+. The ICP-QQQ-MS was capable of detecting trace (>9.34 nmol L−1) levels of Se in serum in the presence of Gd in our simulated post-MRI serum sample. The multi-tune capabilities of the ICP-QQQ-MS may be adapted to eliminate other specific isobaric interferences that cause false positive results in other analyses where the analyte is confounded by doubly charged and/or polyatomic species

    Hotspot autoimmune T cell receptor binding underlies pathogen and insulin peptide cross-reactivity

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    The cross-reactivity of T cells with pathogen- and self-derived peptides has been implicated as a pathway involved in the development of autoimmunity. However, the mechanisms that allow the clonal T cell antigen receptor (TCR) to functionally engage multiple peptide–major histocompatibility complexes (pMHC) are unclear. Here, we studied multiligand discrimination by a human, preproinsulin reactive, MHC class-I–restricted CD8+ T cell clone (1E6) that can recognize over 1 million different peptides. We generated high-resolution structures of the 1E6 TCR bound to 7 altered peptide ligands, including a pathogen-derived peptide that was an order of magnitude more potent than the natural self-peptide. Evaluation of these structures demonstrated that binding was stabilized through a conserved lock-and-key–like minimal binding footprint that enables 1E6 TCR to tolerate vast numbers of substitutions outside of this so-called hotspot. Highly potent antigens of the 1E6 TCR engaged with a strong antipathogen-like binding affinity; this engagement was governed though an energetic switch from an enthalpically to entropically driven interaction compared with the natural autoimmune ligand. Together, these data highlight how T cell cross-reactivity with pathogen-derived antigens might break self-tolerance to induce autoimmune disease

    Transcript assembly and quantification by RNA-Seq reveals unannotated transcripts and isoform switching during cell differentiation

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    High-throughput mRNA sequencing (RNA-Seq) promises simultaneous transcript discovery and abundance estimation. However, this would require algorithms that are not restricted by prior gene annotations and that account for alternative transcription and splicing. Here we introduce such algorithms in an open-source software program called Cufflinks. To test Cufflinks, we sequenced and analyzed >430 million paired 75-bp RNA-Seq reads from a mouse myoblast cell line over a differentiation time series. We detected 13,692 known transcripts and 3,724 previously unannotated ones, 62% of which are supported by independent expression data or by homologous genes in other species. Over the time series, 330 genes showed complete switches in the dominant transcription start site (TSS) or splice isoform, and we observed more subtle shifts in 1,304 other genes. These results suggest that Cufflinks can illuminate the substantial regulatory flexibility and complexity in even this well-studied model of muscle development and that it can improve transcriptome-based genome annotation

    Human leukocyte antigen (HLA) class II peptide flanking residues tune the immunogenicity of a human tumor-derived epitope

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    CD4+ T-cells recognize peptide antigens, in the context of human leukocyte antigen (HLA) class II molecules (HLA-II), which through peptide-flanking residues (PFRs) can extend beyond the limits of the HLA binding. The role of the PFRs during antigen recognition is not fully understood; however, recent studies have indicated that these regions can influence T-cell receptor (TCR) affinity and pHLA-II stability. Here, using various biochemical approaches including peptide sensitivity ELISA and ELISpot assays, peptide-binding assays and HLA-II tetramer staining, we focused on CD4+ T-cell responses against a tumor antigen, 5T4 oncofetal trophoblast glycoprotein (5T4), which have been associated with improved control of colorectal cancer. Despite their weak TCR-binding affinity, we found that anti-5T4 CD4+ T-cells are polyfunctional and that their PFRs are essential for TCR recognition of the core bound nonamer. The high-resolution (1.95 Å) crystal structure of HLA-DR1 presenting the immunodominant 20-mer peptide 5T4111–130, combined with molecular dynamic simulations, revealed how PFRs explore the HLA-proximal space to contribute to antigen reactivity. These findings advance our understanding of what constitutes an HLA-II epitope and indicate that PFRs can tune weak affinity TCR–pHLA-II interactions

    The Microbial Communities in Male First Catch Urine Are Highly Similar to Those in Paired Urethral Swab Specimens

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    Urine is the CDC-recommended specimen for STI testing. It was unknown if the bacterial communities (microbiomes) in urine reflected those in the distal male urethra. We compared microbiomes of 32 paired urine and urethral swab specimens obtained from adult men attending an STD clinic, by 16S rRNA PCR and deep pyrosequencing. Microbiomes of urine and swabs were remarkably similar, regardless of STI status of the subjects. Thus, urine can be used to characterize urethral microbiomes when swabs are undesirable, such as in population-based studies of the urethral microbiome or where multiple sampling of participants is required

    Long-term exposure to air pollution and stroke incidence:A Danish Nurse cohort study

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    Ambient air pollution has been linked to stroke, but few studies have examined in detail stroke subtypes and confounding by road traffic noise, which was recently associated with stroke. Here we examined the association between long-term exposure to air pollution and incidence of stroke (overall, ischemic, hemorrhagic), adjusting for road traffic noise. In a nationwide Danish Nurse Cohort consisting of 23,423 nurses, recruited in 1993 or 1999, we identified 1,078 incident cases of stroke (944 ischemic and 134 hemorrhagic) up to December 31, 2014, defined as first-ever hospital contact. The full residential address histories since 1970 were obtained for each participant and the annual means of air pollutants (particulate matter with diameter < 2.5 μm and < 10 μm (PM2.5 and PM10), nitrogen dioxide (NO2), nitrogen oxides (NOx)) and road traffic noise were determined using validated models. Time-varying Cox regression models were used to estimate hazard ratios (HR) (95% confidence intervals (CI)) for the associations of one-, three, and 23-year running mean of air pollutants with stroke adjusting for potential confounders and noise. In fully adjusted models, the HRs (95% CI) per interquartile range increase in one-year running mean of PM2.5 and overall, ischemic, and hemorrhagic stroke were 1.12 (1.01–1.25), 1.13 (1.01–1.26), and 1.07 (0.80–1.44), respectively, and remained unchanged after adjustment for noise. Long-term exposure to ambient PM2.5 was associated with the risk of stroke independent of road traffic noise
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