2,160 research outputs found

    Evaluation of lncluding Writing in An Introductory Statistics Course

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    This research evaluates including write to learn activities in an introductory statistics course. A review of literature has shown writing is an effective tool for shrdent\u27s learning; it also indicated which types of writing have been more effective for student learning, and the difficulties of successfully including writing in statistics curriculum. Based on these findings, writing activities were designed and incorporated into statistics courses taught at a university. A research study was carried out to determine if including rvrite to learn activities in statistics curriculum would be beneficial for nontraditional students, and to obtain feedback on students\u27perceptions of the write to learn activities. The objectives of the study were to determine if the inclusion of writing activities improved students\u27 ability to set up accurate hypotheses, carry out a hypothesis test, and interpret, in context, the results of a hypothesis test. The research also evaluated if students\u27 perceptions of their learning were impacted by the write to learn activities; and if students\u27 perceptions of their level of statistics anxiety were affected by the write to learn activities. The results of the study showed an increase in the proportion of students who correctly calculated the z-statistic and an increase in the proportion of students who interpreted the results of a hlpothesis test in context. A majority of students had positive impressions of the writing activities,, claiming that the writing exercises were helpful in their learning. In addition, students\u27 anxiety levels were reduced from the beginning of the course

    Who Pays? Coverage Challenges for Cardiovascular Genetic Testing in U.S. Patients

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    Inherited cardiovascular (CV) conditions are common, and comprehensive care of affected families often involves genetic testing. When the clinical presentations of these conditions overlap, genetic testing may clarify diagnoses, etiologies, and treatments in symptomatic individuals and facilitate the identification of asymptomatic, at-risk relatives, allowing for often life-saving preventative care. Although some professional society guidelines on inherited cardiac conditions include genetic testing recommendations, they quickly become outdated owing to the rapid expansion and use of such testing. Currently, these guidelines primarily discuss the benefits of targeted genetic testing for identifying at-risk relatives. Although most insurance policies acknowledge the benefit and the necessity of this testing, many exclude coverage for testing altogether or are vague about coverage for testing in probands, which is imperative if clinicians are to have the best chance of accurately identifying pathogenic variant(s) in a family. In response to uncertainties about coverage, many commercial CV genetic testing laboratories have shouldered the burden of working directly with commercial payers and protecting patients/institutions from out-of-pocket costs. As a result, many clinicians are unaware that payer coverage policies may not match professional recommendations for CV genetic testing. This conundrum has left patients, clinicians, payers, and laboratories at an impasse when determining the best path forward for meaningful and sustainable testing. Herein, we discuss the need for all involved parties to recognize their common goals in this process, which should motivate collaboration in changing existing frameworks and creating more sustainable access to genetic information for families with inherited CV conditions

    Determination of Azimuth Angle at Burnout for Placing a Satellite Over a Selected Earth Position

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    Expressions are presented for relating the satellite position in the orbital plane with the projected latitude and longitude on a rotating earth surface. An expression is also presented for determining the azimuth angle at a given burnout position on the basis of a selected passage position on the earth's surface. Examples are presented of a satellite launched eastward and one launched westward, each passing over a selected position sometime after having completed three orbits. Incremental changes from the desired latitude and longitude due to the earth's oblateness are included in the iteration for obtaining the azimuth angles of the two examples. The results for both cases are then compared with those obtained from a computing program using an oblate rotating earth. Changes from the selected latitude and longitude resulting from incremental changes from the burn-out azimuth angle and latitude are also analyzed

    PtrA is required for coordinate regulation of gene expression during phosphate stress in a marine Synechococcus

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    Previous microarray analyses have shown a key role for the two-component system PhoBR (SYNW0947, SYNW0948) in the regulation of P transport and metabolism in the marine cyanobacterium Synechococcus sp. WH8102. However, there is some evidence that another regulator, SYNW1019 (PtrA), probably under the control of PhoBR, is involved in the response to P depletion. PtrA is a member of the cAMP receptor protein transcriptional regulator family that shows homology to NtcA, the global nitrogen regulator in cyanobacteria. To define the role of this regulator, we constructed a mutant by insertional inactivation and compared the physiology of wild-type Synechcococcus sp. WH8102 with the ptrA mutant under P-replete and P-stress conditions. In response to P stress the ptrA mutant failed to upregulate phosphatase activity. Microarrays and quantitative RT-PCR indicate that a subset of the Pho regulon is controlled by PtrA, including two phosphatases, a predicted phytase and a gene of unknown function psip1 (SYNW0165), all of which are highly upregulated during P limitation. Electrophoretic mobility shift assays indicate binding of overexpressed PtrA to promoter sequences upstream of the induced genes. This work suggests a two-tiered response to P depletion in this strain, the first being PhoB-dependent induction of high-affinity PO4 transporters, and the second the PtrA-dependent induction of phosphatases for scavenging organic P. The levels of numerous other transcripts are also directly or indirectly influenced by PtrA, including those involved in cell-surface modification, metal uptake, photosynthesis, stress responses and other metabolic processes, which may indicate a wider role for PtrA in cellular regulation in marine picocyanobacteria

    In utero and childhood polybrominated diphenyl ether (PBDE) exposures and neurodevelopment in the CHAMACOS study.

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    BackgroundCalifornia children's exposures to polybrominated diphenyl ether flame retardants (PBDEs) are among the highest worldwide. PBDEs are known endocrine disruptors and neurotoxicants in animals.ObjectiveHere we investigate the relation of in utero and child PBDE exposure to neurobehavioral development among participants in CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas), a California birth cohort.MethodsWe measured PBDEs in maternal prenatal and child serum samples and examined the association of PBDE concentrations with children's attention, motor functioning, and cognition at 5 (n = 310) and 7 years of age (n = 323).ResultsMaternal prenatal PBDE concentrations were associated with impaired attention as measured by a continuous performance task at 5 years and maternal report at 5 and 7 years of age, with poorer fine motor coordination-particularly in the nondominant-at both age points, and with decrements in Verbal and Full-Scale IQ at 7 years. PBDE concentrations in children 7 years of age were significantly or marginally associated with concurrent teacher reports of attention problems and decrements in Processing Speed, Perceptual Reasoning, Verbal Comprehension, and Full-Scale IQ. These associations were not altered by adjustment for birth weight, gestational age, or maternal thyroid hormone levels.ConclusionsBoth prenatal and childhood PBDE exposures were associated with poorer attention, fine motor coordination, and cognition in the CHAMACOS cohort of school-age children. This study, the largest to date, contributes to growing evidence suggesting that PBDEs have adverse impacts on child neurobehavioral development

    Maternal Thyroid Function during the Second Half of Pregnancy and Child Neurodevelopment at 6, 12, 24, and 60 Months of Age

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    Although evidence suggests that maternal hypothyroidism and mild hypothyroxinemia during the first half of pregnancy alters fetal neurodevelopment among euthyroid offspring, little data are available from later in gestation. In this study, we measured free T4 using direct equilibrium dialysis, as well as total T4 and TSH in 287 pregnant women at 27 weeks' gestation. We also assessed cognition, memory, language, motor functioning, and behavior in their children at 6, 12, 24, and 60 months of age. Increasing maternal TSH was related to better performance on tests of cognition and language at 12 months but not at later ages. At 60 months, there was inconsistent evidence that higher TSH was related to improved attention. We found no convincing evidence that maternal TH during the second half of pregnancy was related to impaired child neurodevelopment

    Role of intrinsic renal cells versus infiltrating cells in glomerular crescent formation

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    Role of intrinsic renal cells versus infiltrating cells in glomerular crescent formation.BackgroundStudies were undertaken to characterize the cellular composition that occurs in glomeruli and the tubulointerstitium of a passive model of complement-independent crescentic nephritis in mice.MethodsGlomerulonephritis was induced by the injection of antibody to whole rabbit glomeruli, and tissue was examined histologically at 7, 14 and 28days.ResultsMice developed proteinuria, glomerular crescents, and progressive glomerulosclerosis and tubulointerstitial fibrosis. The majority of the cells within the crescents appeared to be intrinsic ezrin-positive epithelial cells of visceral or parietal origin. Many of the ezrin positive cells were proliferating and expressing the PDGF receptor. Despite expression of the macrophage adhesive protein, osteopontin, the early crescents were devoid of infiltrating macrophages, T cells or myofibroblasts, which could be explained by the finding that the Bowman's capsule remained intact. Tubulointerstitial damage also occurred, and included tubular dilation and atrophy, periglomerular and patchy interstitial infiltration and interstitial fibrosis with increased interstitial deposition of type IV collagen and laminin. Interstitial infiltrating cells included macrophages, CD4+ T lymphocytes, CD8+ T lymphocytes, and activated myofibroblasts. Tubular osteopontin expression was increased in the areas of tubulointerstitial damage and was associated with interstitial macrophage infiltration.ConclusionsWe describe an experimental model of complement-independent murine crescentic nephritis associated with tubulointerstitial injury. Proliferating glomerular epithelial cells are the main cellular components of the crescents in this model

    Posture and Locomotion Coupling: A Target for Rehabilitation Interventions in Persons with Parkinson's Disease

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    Disorders of posture, balance, and gait are debilitating motor manifestations of advancing Parkinson's disease requiring rehabilitation intervention. These problems often reflect difficulties with coupling or sequencing posture and locomotion during complex whole body movements linked with falls. Considerable progress has been made with demonstrating the effectiveness of exercise interventions for individuals with Parkinson's disease. However, gaps remain in the evidence base for specific interventions and the optimal content of exercise interventions. Using a conceptual theoretical framework and experimental findings, this perspective and review advances the viewpoint that rehabilitation interventions focused on separate or isolated components of posture, balance, or gait may limit the effectiveness of current clinical practices. It is argued that treatment effectiveness may be improved by directly targeting posture and locomotion coupling problems as causal factors contributing to balance and gait dysfunction. This approach may help advance current clinical practice and improve outcomes in rehabilitation for persons with Parkinson's disease

    The plasma membrane-actin linking protein, ezrin, is a glomerular epithelial cell marker in glomerulogenesis, in the adult kidney and in glomerular injury

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    The plasma membrane-actin linking protein, ezrin, is a glomerular epithelial cell marker in glomerulogenesis, in the adult kidney and in glomerular injury.BackgroundEzrin belongs to a family of plasma membrane-cytoskeleton linking, actin binding proteins (Ezrin-radixin-Moesin family) involved in signal transduction, growth control, cell-cell adhesion, and microvilli formation.MethodsThe expression of ezrin was examined in glomerular cells in culture, during kidney development, in the mature kidney, and in five different experimental kidney disease models in the rat.ResultsEzrin was specifically expressed in glomerular epithelial cells in developing glomeruli in mature glomeruli and in glomerular epithelial cells in culture. Distinct from its other family members, moesin and radixin, which are predominantly expressed in glomerular endothelial and mesangial areas, ezrin protein (by immunohistochemistry) was specifically and exclusively modulated during podocyte injury and regeneration. Ezrin immunohistochemistry was able to visualize cell body attenuation, pseudocysts, and in particular vacuolation of injured podocytes, a feature that usually has to be identified at the ultrastructural level, and was strikingly increased in binucleated podocytes or podocytes that were partially or completely detached from the underlying GBM (frequently also binucleated). Infiltrating macrophages also express ezrin, but can easily be differentiated from podocytes by their round shape and higher level of expression.ConclusionsEzrin likely has a role in the cytoskeletal organization, such as reassembling of actin filaments accompanying podocyte injury and regeneration. Since suitable light microscopic markers for the identification of glomerular epithelial cells are rare, ezrin may also be a useful marker for podocytes in normal and injured glomeruli
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