378 research outputs found

    Kalinia, a New North American Genus for a Species Long Misplaced in Eragrostis (Poaceae, Chloridoideae)

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    Eragrostis obtusiflora (Poaceae, Chloridoideae), a species distributed from the southwestern United States to central Mexico, has long been recognized for exhibiting morphological and anatomical features atypical of Eragrostis. Phylogenetic analyses of nuclear internal transcribed spacer sequences and plastid sequences demonstrate that E. obtusiflora should be excluded from Eragrostis (Eragrostideae) and instead be placed in Cynodonteae, although its position within this tribe was unresolved. Additional data, including anatomical and micromorphological characters, suggest a close relationship with Distichlis. However, differences in spikelet and rhizome characters prevent its inclusion in Distichlis. Therefore, the species is transferred to a newly described genus, Kalinia, as K. obtusiflora

    Precision metering of microliter volumes of biological fluids in micro-gravity

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    Concepts were demonstrated and investigated for transferring accurately known and reproducible microliter volumes of biological fluids from sample container onto dry chemistry slides in microgravity environment. Specific liquid transfer tip designs were compared. Information was obtained for design of a liquid sample handling system to enable clinical chemical analysis in microgravity. Disposable pipet tips and pipet devices that were designed to transfer microliter volumes of biological fluid from a (test tube) sample container in 1-G environment were used during microgravity periods of parabolic trajectories of the KC-135 aircraft. The transfer process was recorded using charge coupled device camera and video cassette equipment. Metering behavior of water, a synthetic aqueous protein solution, and anticoagulated human blood was compared. Transfer of these liquids to 2 substrate materials representative of rapidly wettable and slowly wettable dry chemistry slide surface was compared

    The Evaluation and Effectiveness of an Interdisciplinary Course in Electronic Health Record (EHR) Technology for Health and Rehabilitation Professionals

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    This study examined the effectiveness of an online interdisciplinary course in electronic health record (EHR) technology at the University of Pittsburgh for health and rehabilitation professionals. The purpose of the study was to determine how familiar participants were with EHR technology; determine if attitudes changed toward EHR technology after taking the course; and determine if the course met the needs and expectations of the participants. The goal of the project was to educate health and rehabilitation professionals about EHR technology and to identify a model interdisciplinary course for this topic. Quantitative and qualitative data was collected through questionnaires, practice module exams, and participant interviews. Participants who took the course showed significant gains in their knowledge of almost all of the content areas. The primary strength of the course was its structure, in particular, with the audio presentation. The weaknesses of the course were with regard to the quantity of and time allotted to complete assignments, as well as the desire to have more hands-on vendor component assignments. Although participant attitudes were favorable toward EHR technology before taking the course, they improved after taking the course. Overall participants believed that it is important that EHR technology is implemented in healthcare and benefited significantly from taking the course

    Simulations of Oligomeric Intermediates in Prion Diseases

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    We extend our previous stochastic cellular automata based model for areal aggregation of prion proteins on neuronal surfaces. The new anisotropic model allow us to simulate both strong beta-sheet and weaker attachment bonds between proteins. Constraining binding directions allows us to generate aggregate structures with the hexagonal lattice symmetry found in recently observed in vitro experiments. We argue that these constraints on rules may correspond to underlying steric constraints on the aggregation process. We find that monomer dominated growth of the areal aggregate is too slow to account for some observed doubling time-to-incubation time ratios inferred from data, and so consider aggregation dominated by relatively stable but non-infectious oligomeric intermediates. We compare a kinetic theory analysis of oligomeric aggregation to spatially explicit simulations of the process. We find that with suitable rules for misfolding of oligomers, possibly due to water exclusion by the surrounding aggregate, the resulting oligomeric aggregation model maps onto our previous monomer aggregation model. Therefore it can produce some of the same attractive features for the description of prion incubation time data. We propose experiments to test the oligomeric aggregation model.Comment: 8 pages, 10 figures For larger versions of several figures, see http://asaph.ucdavis.edu/~dmobley and click on the prion paper lin

    MAPK phosphorylation of connexin 43 promotes binding of cyclin E and smooth muscle cell proliferation

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    <p>Rationale: Dedifferentiation of vascular smooth muscle cells (VSMC) leading to a proliferative cell phenotype significantly contributes to the development of atherosclerosis. Mitogen-activated protein kinase (MAPK) phosphorylation of proteins including connexin 43 (Cx43) has been associated with VSMC proliferation in atherosclerosis.</p> <p>Objective: To investigate whether MAPK phosphorylation of Cx43 is directly involved in VSMC proliferation.</p> <p>Methods and Results: We show in vivo that MAPK-phosphorylated Cx43 forms complexes with the cell cycle control proteins cyclin E and cyclin-dependent kinase 2 (CDK2) in carotids of apolipoprotein-E receptor null (ApoE−/−) mice and in C57Bl/6 mice treated with platelet-derived growth factor–BB (PDGF). We tested the involvement of Cx43 MAPK phosphorylation in vitro using constructs for full-length Cx43 (Cx43) or the Cx43 C-terminus (Cx43CT) and produced null phosphorylation Ser>Ala (Cx43MK4A/Cx43CTMK4A) and phospho-mimetic Ser>Asp (Cx43MK4D/Cx43CTMK4D) mutations. Coimmunoprecipitation studies in primary VSMC isolated from Cx43 wild-type (Cx43+/+) and Cx43 null (Cx43−/−) mice and analytic size exclusion studies of purified proteins identify that interactions between cyclin E and Cx43 requires Cx43 MAPK phosphorylation. We further demonstrate that Cx43 MAPK phosphorylation is required for PDGF-mediated VSMC proliferation. Finally, using a novel knock-in mouse containing Cx43-MK4A mutation, we show in vivo that interactions between Cx43 and cyclin E are lost and VSMC proliferation does not occur after treatment of carotids with PDGF and that neointima formation is significantly reduced in carotids after injury.</p> <p>Conclusions: We identify MAPK-phosphorylated Cx43 as a novel interacting partner of cyclin E in VSMC and show that this interaction is critical for VSMC proliferation. This novel interaction may be important in the development of atherosclerotic lesions.</p&gt

    Schaffnerella Rediscovered! (Gramineae, Chloridoideae)

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    From 1876 to 1880 in San Luis PotosĂ­, Mexico, J. G. Schaffner made the first collections of a small grass that later was named Schaffnerella gracilis (Chloridoideae). The monotypic genus apparently was not encountered again by botanists until 2001, when, during a targeted search, we discovered it in the Sierra de San Miguelito growing along the RĂ­o Potosino, ca. 6 air km southwest of the city of San Luis PotosĂ­. Most of the 100-150 plants encountered along a 3-km stretch of the RĂ­o Potosino above the village of Escalerillas and reservoir EI Potosino were growing in a moist alluvium of rock and sand. Historically known to occur some 10 km or more downstream near Morales, a village at the western edge of the city of San Luis PotosĂ­, S. gracilis has been impacted adversely by the creation of dams. Much additional field work is required to determine the geographic range and frequency of the species. Also needed are life history and population-level studies

    Knowledge Transfer and Teaching Public Administration: the Academy Model

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    Since the beginnings of Public Administration in the US and its accompanying education in other parts of the world, government and policy have become more complex. The education in Public Administration created a professional pathway to public service. The addition of education to Public Administration came out of the Progressive Movement in the United States to make knowledge in Public Administration more important in the face of corruption brought on by patronage appointments. When nonprofits became part the US public sector as elsewhere along with nonprofit healthcare, the complexity expanded enormously, requiring professionals to know more in what has become a multidisciplinary field of study. Given the diversity and complexity of the public sector and the need for Public Administration to embrace more knowledge from many disciplines, it stands to reason that an earlier start on the education portion of Public Administration or a pathway would be beneficial. A model of early Public Administration knowledge transfer is described and illustrated below. The Academy described is based on the US career pathways and high school academies as part of the school to work educational movement. The success of the combination of these two areas will also be pointed out in the academy described. Translation of lessons learned from the Acdemy to Europe and Asia are also considered

    Phylogenetics of Chloridoideae (Gramineae): a Preliminary Study Based on Nuclear Ribosomal Internal Transcribed Spacer and Chloroplast trnL–F Sequences

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    The phylogeny of Chloridoideae (Gramineae) was inferred from parsimony analyses of DNA sequences from two genomes—the chloroplast trnL intron, trnL 3\u27 exon, and trnL–F intergenic spacer, and the nuclear ribosomal internal transcribed spacer region (ITS1 + 5.8S + ITS2). Eighty species representing 66 chloridoid genera were sampled, including all but four of the native New World genera. Analyses of the individual and combined data sets were performed. The phylogenies were found to be highly congruent. Of the four tribes and seven subtribes of Chloridoideae sensu Clayton and Renvoize (1986) whose phylogenetic status could be tested with our taxon sample, only Orcuttieae and Uniolinae were monophyletic. The phylogenies suggested signiïŹcant homoplasy in morphological traits, including inïŹ‚orescence type, number of ïŹ‚orets per spikelet, and number of lemma nerves. We propose a new classiïŹcation based on the three main clades in the phylogenies—tribes Cynodonteae, Eragrostideae, and Zoysieae. The Eragrostideae clade is well resolved and supported and is further divided into three subtribes, Cotteinae, Eragrostidinae, and Uniolinae. Cynodonteae include most of the genera in our study, but the clade is poorly resolved. However, a clade formed of Muhlenbergia and nine other genera is present in both phylogenies and is well resolved and supported. A number of interesting, well-supported relationships are evident in the phylogenies, including Pappophorum–Tridens ïŹ‚avus, Tragus–Willkommia, and Gouinia–Tridens muticus–Triplasis–Vaseyochloa. Except for Bouteloua, no genus represented by multiple species proved to be monophyletic in the phylogenies

    A multifrequency electron spin resonance study of T4 Lysozyme dynamics using the slowly relaxing local structure model

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    Electron spin resonance (ESR) spectra were obtained at 250 and 9 GHz for nitroxide-labeled mutants of the protein T4 lysozyme in aqueous solution over a range of temperatures from 2 to 37.5°C. Two mutants labeled at sites 72 and 131 were studied and compared. The mutant sites are solvent exposed and free of tertiary interactions with other side chains, but the former is at the center of a 5 turn helix, whereas the latter site is on a small two and a half turn helix. The 250 GHz ESR spectra, because of their "fast time scale", are rather insensitive to the slow overall tumbling motion of the protein. Thus, they are qualitatively different for the two mutants, implying that there are different local dynamics at the two sites. The 9 GHz spectra, which are significantly affected by the overall tumbling and are less sensitive to the internal dynamics, do not show such marked differences between the two sites. The 250 and 9 GHz spectra for each mutant and temperature were simultaneously fit to the slowly relaxing local structure (SRLS) model for slow-motional ESR, using newly developed software. The SRLS model explicitly accounts for the overall tumbling of the protein and the internal modes of motion, which include the motion of the nitroxide side chain (expected to be the same for both mutants) and backbone fluctuations. Very good simultaneous fits are obtained. Whereas two conformers (or spectral components) are typically detected at the lower temperatures, only a single component is observed at the higher temperatures. The significant differences in the high-frequency spectra for the two mutants are readily attributed mainly to a difference in their respective local ordering. That is, site 72 exhibits significantly greater local ordering than does site 131, which is expected from the greater rigidity of the larger helix on which the 72 site is located. The results of this multifrequency study are compared with a previous 9 GHz study. A description of the application of the SRLS model in such a multifrequency study is provided
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