4,374 research outputs found

    Mandatory Community Service: Citizenship Education or Involuntary Servitude?

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    A popular topic of conversation lately among parents, educators, policymakers, students and the media is the isolation of young people from their communities. Many people feel schools have a responsibility to build bridges among diverse populations of children and youth, provide nonviolent problem-solving experiences and promote positive activities for young people, even during after-school hours. Involving young people in community service is seen as one potential solution. Indeed, some citizens and educators would like to ensure that all students — including those least likely to participate voluntarily but most likely to benefit from the experience — have the opportunity to help others and contribute to their communities. An increasingly popular way to do this is to require students to complete a certain number of service hours as part of their school experience

    Astroglial-axonal interactions during early stages of myelination in mixed cultures using in vitro and ex vivo imaging techniques

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    <b>Background</b><p></p> Myelination is a very complex process that requires the cross talk between various neural cell types. Previously, using cytosolic or membrane associated GFP tagged neurospheres, we followed the interaction of oligodendrocytes with axons using time-lapse imaging in vitro and ex vivo and demonstrated dynamic changes in cell morphology. In this study we focus on GFP tagged astrocytes differentiated from neurospheres and their interactions with axons.<p></p> <b>Results</b><p></p> We show the close interaction of astrocyte processes with axons and with oligodendrocytes in mixed mouse spinal cord cultures with formation of membrane blebs as previously seen for oligodendrocytes in the same cultures. When GFP-tagged neurospheres were transplanted into the spinal cord of the dysmyelinated shiverer mouse, confirmation of dynamic changes in cell morphology was provided and a prevalence for astrocyte differentiation compared with oligodendroglial differentiation around the injection site. Furthermore, we were able to image GFP tagged neural cells in vivo after transplantation and the cells exhibited similar membrane changes as cells visualised in vitro and ex vivo.<p></p> <b>Conclusion</b><p></p> These data show that astrocytes exhibit dynamic cell process movement and changes in their membrane topography as they interact with axons and oligodendrocytes during the process of myelination, with the first demonstration of bleb formation in astrocytes

    Qualitative Assessment of Risk for Monkeypox Associated with Domestic Trade in Certain Animal Species, United States

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    TOC summary: The probability of further human infection is low and the risk is further mitigated by rodent import restrictions

    Irisin Treatment during Chronic Inflammatory Bowel Disease in an Rodent Model Improves Bone Formation Rate

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    Bone is a dynamic tissue that responds to many stressors including physical stress and certain disease states. Chronic systemic inflammatory conditions, like inflammatory bowel disease (IBD), result in increased bone resorption and decreased bone formation leading to low bone mass and high fracture incidence. There currently are no effective, safe treatments for IBD. Irisin is a hormone that is released during exercise and has previously been shown to increase bone mass. PURPOSE: Determine if exogenous treatment with irisin can mitigate the inflammatory insult of chronic IBD on bone. We hypothesized that young male rats with induced IBD and treatment with exogenous irisin would have increased bone formation rate (BFR) and mitigated loss of bone mineral density compared to rats with only IBD. METHOD: Male Sprague Dawley rats (2 months) were divided into four groups: controls (CON), those given dextran sodium sulfate in drinking water to induce IBD (DSS), CON rats given exogenous irisin (CON+IR), and DSS rats given exogenous irisin (DSS+IR). n per group=8.. Irisin injections began one week after initiation of IBD for the remainder of the four week protocol. RESULTS: Peripheral quantitative computed tomography (pQCT) of the proximal tibia metaphysis showed a significant decrease in total bone mineral content and volumetric bone mineral density (cortical shell+cancellous core) in both DSS groups compared to both control groups. Dynamic histomorphomery revealed higher cancellous BFR due to irisin treatment in both CON and DSS rats resulting in DSS+IR having higher BFR than DSS. This was due largely to increases in mineralized surface indicating increased numbers of osteoblast teams. At the midshaft tibia, BFR was higher in DSS+IR, but not significantly different than DSS alone. This change was due more to increases in mineral apposition rate indicating higher activity of osteoblast teams. CONCLUSION: In this study, we demonstrated that rats with DSS have low bone mass similar to patients with IBD. Although irisin did not mitigate this bone loss, our data indicates over time it would likely lead to improved bone mass due to increases in bone formation. Additionally, our data indicate greater improvements in BFR in the cancellous bone, a more active bone compartment, than the midshaft tibia, but slight increases in mineral apposition rate at this site demonstrate improved osteoblast activity due to irisin. Since IBD is a chronic, life-long disease, our data highlights the potential benefit of exogenous irisin treatment as well as exercise therapy for patients with IBD

    On queue audience--calculating reach and frequency for supermarket television

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    Thesis (M.S.)--Massachusetts Institute of Technology, Sloan School of Management, 1991.Includes bibliographical references (p. 78-81).by Susan M.L. Anderson.M.S

    Ethnicity and the Writing of Medieval Scottish history

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    Historians have long tended to define medieval Scottish society in terms of interactions between ethnic groups. This approach was developed over the course of the long nineteenth century, a formative period for the study of medieval Scotland. At that time, many scholars based their analysis upon scientific principles, long since debunked, which held that medieval 'peoples' could only be understood in terms of 'full ethnic packages'. This approach was combined with a positivist historical narrative that defined Germanic Anglo-Saxons and Normans as the harbingers of advances of Civilisation. While the prejudices of that era have largely faded away, the modern discipline still relies all too often on a dualistic ethnic framework. This is particularly evident in a structure of periodisation that draws a clear line between the 'Celtic' eleventh century and the 'Norman' twelfth. Furthermore, dualistic oppositions based on ethnicity continue, particularly in discussions of the law, kingship, lordship and religion

    Educating Future Nursing Scientists: Recommendations for Integrating Omics Content in PhD Programs

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    Preparing the next generation of nursing scientists to conduct high-impact, competitive, sustainable, innovative, and interdisciplinary programs of research requires that the curricula for PhD programs keep pace with emerging areas of knowledge and health care/biomedical science. A field of inquiry that holds great potential to influence our understanding of the underlying biology and mechanisms of health and disease is omics. For the purpose of this article, omics refers to genomics, transcriptomics, proteomics, epigenomics, exposomics, microbiomics, and metabolomics. Traditionally, most PhD programs in schools of nursing do not incorporate this content into their core curricula. As part of the Council for the Advancement of Nursing Science\u27s Idea Festival for Nursing Science Education, a work group charged with addressing omics preparation for the next generation of nursing scientists was convened. The purpose of this article is to describe key findings and recommendations from the work group that unanimously and enthusiastically support the incorporation of omics content into the curricula of PhD programs in nursing. The work group also calls to action faculty in schools of nursing to develop strategies to enable students needing immersion in omics science and methods to execute their research goals

    Evaluating concentration estimation errors in ELISA microarray experiments

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    BACKGROUND: Enzyme-linked immunosorbent assay (ELISA) is a standard immunoassay to estimate a protein's concentration in a sample. Deploying ELISA in a microarray format permits simultaneous estimation of the concentrations of numerous proteins in a small sample. These estimates, however, are uncertain due to processing error and biological variability. Evaluating estimation error is critical to interpreting biological significance and improving the ELISA microarray process. Estimation error evaluation must be automated to realize a reliable high-throughput ELISA microarray system. In this paper, we present a statistical method based on propagation of error to evaluate concentration estimation errors in the ELISA microarray process. Although propagation of error is central to this method and the focus of this paper, it is most effective only when comparable data are available. Therefore, we briefly discuss the roles of experimental design, data screening, normalization, and statistical diagnostics when evaluating ELISA microarray concentration estimation errors. RESULTS: We use an ELISA microarray investigation of breast cancer biomarkers to illustrate the evaluation of concentration estimation errors. The illustration begins with a description of the design and resulting data, followed by a brief discussion of data screening and normalization. In our illustration, we fit a standard curve to the screened and normalized data, review the modeling diagnostics, and apply propagation of error. We summarize the results with a simple, three-panel diagnostic visualization featuring a scatterplot of the standard data with logistic standard curve and 95% confidence intervals, an annotated histogram of sample measurements, and a plot of the 95% concentration coefficient of variation, or relative error, as a function of concentration. CONCLUSIONS: This statistical method should be of value in the rapid evaluation and quality control of high-throughput ELISA microarray analyses. Applying propagation of error to a variety of ELISA microarray concentration estimation models is straightforward. Displaying the results in the three-panel layout succinctly summarizes both the standard and sample data while providing an informative critique of applicability of the fitted model, the uncertainty in concentration estimates, and the quality of both the experiment and the ELISA microarray process

    Paleolimnological Evidence of Terrestrial and Lacustrine Environmental Change in Response to European Settlement of the Red River Valley, Manitoba and North Dakota

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    Limnological and terrestrial changes in three floodplain lakes are correlated with settlement of the Red River valley in Manitoba and North Dakota. Distinctive pollen, diatom and thecamoebian assemblages provide proxy evidence of the ecological changes from pre- to post-settlement periods in Horseshoe Lake, Lake Louise and Salt Lake. In the pre-settlement period (Zone I), prior to ~1812, grass and Quercus pollen dominate and are indicative of a tall grass prairie-oak riparian forest ecosystem. Diatom and thecamoebian assemblages suggest oligo- to mesotrophic limnological conditions, and more brackish water than presently occurs in Horseshoe Lake. The onset of the post-settlement period (Zone II) corresponds to distinctive terrestrial and limnological changes. A sharp decline in Quercus at the base of this zone correlates with documented regional riparian deforestation, whereas the increase in the weed taxa Salsola, Brassica, Rumex and Ambrosia is associated with the introduction of European agricultural practices and cereal grasses. Diatom and thecamoebian assemblages indicate progressive floodplain lake eutrophication, as well as increased salinity in Salt Lake. Salt Lake is the most brackish lake and supports the brackish-water foraminifera Trochammina macrescens cf. polystoma. Increased erosion and run off in the watershed has caused a more than twofold increase in lake basin sedimentation between the pre-settlement and post-settlement periods.Cette étude établit une corrélation entre les changements limnologiques et terrestres dans la plaine d’inondation de trois lacs et le peuplement de la vallée de la rivière Rouge au Manitoba et dans le Dakota du Nord. Divers assemblages polliniques, de diatomées et de thécamoébiens mettent en évidence de façon indirecte des changements écologiques entre les périodes pré- et post-peuplement aux alentours des lacs Horseshoe, Louise et Salt. Dans la période antérieure au peuplement (Zone I), soit avant 1812, la domination de la signature pollinique des graminées et du chêne indique un écosystème forestier riverain composé de graminées de haute taille et de chênes. Quant aux assemblages de diatomées et de thécamoébiens, ils permettent de penser à des conditions limnologiques d’oligo à mésotrophiques et des eaux plus saumâtres à cette période qu’actuellement dans le lac Horseshoe. La période post-peuplement (Zone II) correspond à des changements terrestres et limnologiques spécifiques. Le déclin marqué du chêne à la base de cette zone correspond en effet à la déforestation des rives de cette région, telle qu’attestée dans les documents, tandis que les taxons Salsola, Brassica, Rumex et Ambrosia correspondent à l’instauration de pratiques agricoles européennes et la culture des céréales. Les assemblages de diatomées et de thécamoébiens indiquent aussi une eutrophisation progressive de la plaine inondable de même que l’augmentation de la salinité du lac Salt, ce dernier étant le plus salé des trois lacs. Il accueille des foraminifères d’eaux saumâtres du genre Trochammina macrescens cf. polystoma. L’accroissement de l’érosion et du ruissellement dans le bassin-versant a quadruplé la sédimentation entre les périodes pré- et post-peuplement

    Report on an all-sky LIGO search for periodic gravitational waves in the S4 data

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    We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50-1000 Hz and having a negative frequency time derivative with magnitude between zero and 10810^{-8} Hz/s. Data from the fourth LIGO science run have been used in this search. Three different semi-coherent methods of summing strain power were applied. Observing no evidence for periodic gravitational radiation, we report upper limits on strain amplitude and interpret these limits to constrain radiation from rotating neutron stars.Comment: 5 pages, 1 figure, presented at Amaldi7, Sydney (July 2007
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