2,512 research outputs found

    Academic Agenda, Goal Setting, and African American Male Student Persistence at a Predominantly Black Institution

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    Low African American male student graduation rates in the United States have been a concern for higher education administrators, and more strategies to address their challenges are needed. This basic qualitative study addressed the experiences of African American male students who persisted to graduation at a predominantly Black institution in the northeastern United States. The institutional departure model and goal setting theory formed the conceptual framework for the study. Nine African American males who graduated from the institution described their experiences with academic goal setting and a graduation agenda, through one-on-one interviews. Key findings included the challenges of financial concerns, making supportive connections, and being engaged with university life. Goal setting and pursuing a graduation agenda were supported by interacting regularly with diverse faculty and staff, having work study positions, and participating in athletics and student organizations. Moments of individual connection and support from staff and faculty members helped students pursue academic goals. The project constructed to address the gaps is a 3-day professional development curriculum. Professional development is necessary to ensure all members of campus are focused on the orientation of first year students and their families to support retention through graduation. Academic agenda and goal setting can and should occur across campus and in multiple settings. Positive social change implications of the project include increased stakeholder awareness of supports necessary to retain African American male students in predominantly Black institutions

    Multi-Scale Modeling of Hypertension

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    The focus of this work is the coupling of a 1-D lumped parameter model representing the circulatory system to a 3-D finite element based left ventricle (LV) model in order to study the effects of mild hypertension on the cardiovascular system. A Finite Element LV model under normotensive loading (116/80 mmHg) was developed as well as a mild hypertension (165/90 mmHg) model. In both cases, coupled analysis was utilized so that at one diastolic time point and four systolic time points the values for the LV volumes and pressures were determined from the steady-state JSim solution. The normotensive model had an average first principal stress of 39.1KPa while the hypertensive case showed an increased value of 51.8KPa representing a 32.3 % increase. A relatively mild increase in the afterload resulted in a pronounced increase in workload to maintain the same systemic flow. 1

    The structure of a resuscitation-promoting factor domain from Mycobacterium tuberculosis shows homology to lysozymes

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    Resuscitation-promoting factor (RPF) proteins reactivate stationary-phase cultures of (G+C)-rich Gram-positive bacteria including the causative agent of tuberculosis, Mycobacterium tuberculosis. We report the solution structure of the RPF domain from M. tuberculosis Rv1009 (RpfB) solved by heteronuclear multidimensional NMR. Structural homology with various glycoside hydrolases suggested that RpfB cleaved oligosaccharides. Biochemical studies indicate that a conserved active site glutamate is important for resuscitation activity. These data, as well as the presence of a clear binding pocket for a large molecule, indicate that oligosaccharide cleavage is probably the signal for revival from dormancy

    Genetic Tests for Ecological and Allopatric Speciation in Anoles on an Island Archipelago

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    From Darwin's study of the Galapagos and Wallace's study of Indonesia, islands have played an important role in evolutionary investigations, and radiations within archipelagos are readily interpreted as supporting the conventional view of allopatric speciation. Even during the ongoing paradigm shift towards other modes of speciation, island radiations, such as the Lesser Antillean anoles, are thought to exemplify this process. Geological and molecular phylogenetic evidence show that, in this archipelago, Martinique anoles provide several examples of secondary contact of island species. Four precursor island species, with up to 8 mybp divergence, met when their islands coalesced to form the current island of Martinique. Moreover, adjacent anole populations also show marked adaptation to distinct habitat zonation, allowing both allopatric and ecological speciation to be tested in this system. We take advantage of this opportunity of replicated island coalescence and independent ecological adaptation to carry out an extensive population genetic study of hypervariable neutral nuclear markers to show that even after these very substantial periods of spatial isolation these putative allospecies show less reproductive isolation than conspecific populations in adjacent habitats in all three cases of subsequent island coalescence. The degree of genetic interchange shows that while there is always a significant genetic signature of past allopatry, and this may be quite strong if the selection regime allows, there is no case of complete allopatric speciation, in spite of the strong primae facie case for it. Importantly there is greater genetic isolation across the xeric/rainforest ecotone than is associated with any secondary contact. This rejects the development of reproductive isolation in allopatric divergence, but supports the potential for ecological speciation, even though full speciation has not been achieved in this case. It also explains the paucity of anole species in the Lesser Antilles compared to the Greater Antilles

    Tenecteplase for ST-elevation myocardial infarction in a patient treated with drotrecogin alfa (activated) for severe sepsis: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Drotrecogin alfa (activated) (DrotAA), an activated protein C, promotes fibrinolysis in patients with severe sepsis. There are no reported cases or studies that address the diagnosis and treatment of myocardial infarction in septic patients treated with DrotAA.</p> <p>Case presentation</p> <p>A 59-year-old Caucasian man with septic shock secondary to community-acquired pneumonia treated with DrotAA, subsequently developed an ST-elevation myocardial infarction 12 hours after starting DrotAA. DrotAA was stopped and the patient was given tenecteplase thrombolysis resulting in complete resolution of ST-elevation and no adverse bleeding events. DrotAA was restarted to complete the 96-hour course. The sepsis resolved and the patient was discharged from hospital.</p> <p>Conclusion</p> <p>In patients with severe sepsis or septic shock complicated by myocardial infarction, it is difficult to determine if the myocardial infarction is an isolated event or caused by the sepsis process. The efficacy and safety of tenecteplase thrombolysis in septic patients treated with DrotAA need further study.</p

    Analysis of the association between spawning time QTL markers and the biannual spawning behavior in rainbow trout (Oncorhynchus mykiss)

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    The rainbow trout is a salmonid fish that occasionally exhibits broodstocks with biannual spawning behavior, a phenomenon known as a double annual reproductive cycle (DARC). Spawning time quantitative trait loci (SPT-QTLs) affect the time of the year that female rainbow trout spawn and may influence expression of the DARC trait. In this study, microsatellite markers linked and unlinked to SPT-QTLs were genotyped to investigate the underlying genetics of this trait. SPT-QTLs influenced the DARC trait since in two case-control comparisons three linked markers (OmyFGT12TUF, One3ASC and One19ASC) had significant levels of allelic frequency differentiation and marker-character association. Furthermore, alleles of One3ASC and One19ASC had significantly higher frequencies in populations that carried the DARC trait

    Characterisation of polymorphic microsatellite loci in the western rock lobster

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    Nine microsatellite loci were identified in the western rock lobster (Panulirus cygnus) using two different methods. The first method involved the screening of a small, fragment, partial genomic library with a radioactive (CA) 6 probe. The second method, was based upon an enrichment method and used biotinylated, tetranucleotide microsatellite oligonucleotide capture probes. The nine loci described are all very polymorphic, with 11 to 34 alleles observed for each locus and heterozygosities ranging from 0.58 to 0.86. These microsatellite loci will be useful in analysing both the population structure and the mating systems used by this species and will add important information for the management of the wild stocks of this economically important species. © Springer Science+Business Media B.V. 2009

    QRTEngine: An easy solution for running online reaction time experiments using Qualtrics

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    Performing online behavioral research is gaining increased popularity among researchers in psychological and cognitive science. However, the currently available methods for conducting online reaction time experiments are often complicated and typically require advanced technical skills. In this article, we introduce the Qualtrics Reaction Time Engine (QRTEngine), an open-source JavaScript engine that can be embedded in the online survey development environment Qualtrics. The QRTEngine can be used to easily develop browser-based online reaction time experiments with accurate timing within current browser capabilities, and it requires only minimal programming skills. After introducing the QRTEngine, we briefly discuss how to create and distribute a Stroop task. Next, we describe a study in which we investigated the timing accuracy of the engine under different processor loads using external chronometry. Finally, we show that the QRTEngine can be used to reproduce classic behavioral effects in three reaction time paradigms: a Stroop task, an attentional blink task, and a masked-priming task. These findings demonstrate that QRTEngine can be used as a tool for conducting online behavioral research even when this requires accurate stimulus presentation times

    Planet Populations as a Function of Stellar Properties

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    Exoplanets around different types of stars provide a window into the diverse environments in which planets form. This chapter describes the observed relations between exoplanet populations and stellar properties and how they connect to planet formation in protoplanetary disks. Giant planets occur more frequently around more metal-rich and more massive stars. These findings support the core accretion theory of planet formation, in which the cores of giant planets form more rapidly in more metal-rich and more massive protoplanetary disks. Smaller planets, those with sizes roughly between Earth and Neptune, exhibit different scaling relations with stellar properties. These planets are found around stars with a wide range of metallicities and occur more frequently around lower mass stars. This indicates that planet formation takes place in a wide range of environments, yet it is not clear why planets form more efficiently around low mass stars. Going forward, exoplanet surveys targeting M dwarfs will characterize the exoplanet population around the lowest mass stars. In combination with ongoing stellar characterization, this will help us understand the formation of planets in a large range of environments.Comment: Accepted for Publication in the Handbook of Exoplanet
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