693 research outputs found

    Integrating the Genetic and Physical Maps of Arabidopsis thaliana: Identification of Mapped Alleles of Cloned Essential (EMB) Genes

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    The classical genetic map of Arabidopsis includes more than 130 genes with an embryo-defective (emb) mutant phenotype. Many of these essential genes remain to be cloned. Hundreds of additional EMB genes have been cloned and catalogued (www.seedgenes.org) but not mapped. To facilitate EMB gene identification and assess the current level of saturation, we updated the classical map, compared the physical and genetic locations of mapped loci, and performed allelism tests between mapped (but not cloned) and cloned (but not mapped) emb mutants with similar chromosome locations. Two hundred pairwise combinations of genes located on chromosomes 1 and 5 were tested and more than 1100 total crosses were screened. Sixteen of 51 mapped emb mutants examined were found to be disrupted in a known EMB gene. Alleles of a wide range of published EMB genes (YDA, GLA1, TIL1, AtASP38, AtDEK1, EMB506, DG1, OEP80) were discovered. Two EMS mutants isolated 30 years ago, T-DNA mutants with complex insertion sites, and a mutant with an atypical, embryo-specific phenotype were resolved. The frequency of allelism encountered was consistent with past estimates of 500 to 1000 EMB loci. New EMB genes identified among mapped T-DNA insertion mutants included CHC1, which is required for chromatin remodeling, and SHS1/AtBT1, which encodes a plastidial nucleotide transporter similar to the maize Brittle1 protein required for normal endosperm development. Two classical genetic markers (PY, ALB1) were identified based on similar map locations of known genes required for thiamine (THIC) and chlorophyll (PDE166) biosynthesis. The alignment of genetic and physical maps presented here should facilitate the continued analysis of essential genes in Arabidopsis and further characterization of a broad spectrum of mutant phenotypes in a model plant

    Tradeoff between Stability and Maneuverability during Whole-Body Movements

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    Understanding how stability and/or maneuverability affects motor control strategies can provide insight on moving about safely in an unpredictable world. Stability in human movement has been well-studied while maneuverability has not. Further, a tradeoff between stability and maneuverability during movement seems apparent, yet has not been quantified. We proposed that greater maneuverability, the ability to rapidly and purposefully change movement direction and speed, is beneficial in uncertain environments. We also hypothesized that gaining maneuverability comes at the expense of stability and perhaps also corresponds with decreased muscle coactivation.We used a goal-directed forward lean movement task that integrated both stability and maneuverability. Subjects (n = 11) used their center of pressure to control a cursor on a computer monitor to reach a target. We added task uncertainty by shifting the target anterior-posterior position mid-movement. We used a balance board with a narrow beam that reduced the base of support in the medio-lateral direction and defined stability as the probability that subjects could keep the balance board level during the task.During the uncertainty condition, subjects were able to change direction of their anterior-posterior center of pressure more rapidly, indicating that subjects were more maneuverable. Furthermore, medio-lateral center of pressure excursions also approached the edges of the beam and reduced stability margins, implying that subjects were less stable (i.e. less able to keep the board level). On the narrow beam board, subjects increased muscle coactivation of lateral muscle pairs and had greater muscle activity in the left leg. However, there were no statistically significant differences in muscle activity amplitudes or coactivation with uncertainty.These results demonstrate that there is a tradeoff between stability and maneuverability during a goal-directed whole-body movement. Tasks with added uncertainty could help individuals learn to be more maneuverable yet sufficiently stable

    An evaluation of Canada's Compassionate Care Benefit from a family caregiver's perspective at end of life

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    <p>Abstract</p> <p>Background</p> <p>The goal of Canada's Compassionate Care Benefit (CCB) is to enable family members and other loved ones who are employed to take a temporary <it>secured </it>leave to care for a terminally ill individual at end of life. Successful applicants of the CCB can receive up to 55% of their average insured earnings, up to a maximum of CDN$435 per week, over a six week period to provide care for a gravely ill family member at risk of death within a six month period, as evidenced by a medical certificate. The goal of this study is to evaluate the CCB from the perspective of family caregivers providing care to individuals at end of life. There are three specific research objectives. Meeting these objectives will address our study purpose which is to make policy-relevant recommendations informed by the needs of Canadian family caregivers and input from other key stakeholders who shape program uptake. Being the first study that will capture family caregivers' experiences and perceptions of the CCB and gather contextual data with front-line palliative care practitioners, employers, and human resources personnel, we will be in a unique position to provide policy solutions/recommendations that will address concerns raised by numerous individuals and organizations.</p> <p>Methods</p> <p>We will achieve the research goal and objectives through employing utilization-focused evaluation as our methodology, in-depth interviews and focus groups as our techniques of data collection, and constant comparative as our technique of data analysis. Three respondent groups will participate: (1) family caregivers who are providing or who have provided end of life care via phone interview; (2) front-line palliative care practitioners via phone interview; and (3) human resources personnel and employers via focus group. Each of these three groups has a stake in the successful administration of the CCB. A watching brief of policy documents, grey literature, media reports, and other relevant items will also be managed throughout data collection.</p> <p>Discussion</p> <p>We propose to conduct this study over a three year period beginning in October, 2006 and ending in October, 2009.</p

    Plan de negocio para la creación de la empresa Smart aura especializada en la comercialización e instalación de equipo domótico en la ciudad de Bogotá

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    EmprendimientoEl presente trabajo tuvo como finalidad la elaboración de un plan de negocio para la creación y formalización de la empresa Smart Aura S.A.S. Con el fin de garantizar la viabilidad técnica y económica-financiera para dicha empresa, el correspondiente trabajo conto con la realización del estudio de mercado propio. Apoyados en dicho estudio se elaboró el plan de negocio, finalizando con el proceso de formalización de la empresa ante las autoridades colombianas certificando el cumplimiento de los requisitos legales exigidos para el adecuado funcionamiento de las empresas en territorio nacional.INTRODUCCIÓN 1. GENERALIDADES 2. ESTUDIO DE MERCADO 3. PLAN DE NEGOCIO 4. FORMALIZACIÓN DEL PLAN DE NEGOCIO 5. CONCLUSIONES 6. RECOMENDACIONES BIBLIOGRAFÍA ANEXOSPregradoIngeniero Industria

    Controlling liver cancer internationally: A qualitative study of clinicians' perceptions of current public policy needs

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    <p>Abstract</p> <p>Background</p> <p>Liver cancer is the fifth most common cancer in men and the seventh for women. Usually because of late diagnosis, the prognosis for liver cancer remains poor, resulting in liver cancer being the third most common cause of death from cancer. While some countries have treatment guidelines, little is known or understood about the strategies needed for liver cancer control internationally.</p> <p>Objective</p> <p>To explore leading liver cancer clinician's perceptions of the current public policy needs to control liver cancer internationally.</p> <p>Methods</p> <p>Key informant interviews were conducted with a range of liver cancer clinicians involved in policy in eleven countries. Interviews were digitally recorded, transcribed verbatim, translated (where necessary), de-identified and analyzed by two researchers using a constant comparative method.</p> <p>Results</p> <p>Twenty in-depth semi-structured interviews were conducted in: Australia, China, France, Germany, Italy, Japan, Spain, South Korea, Taiwan, Turkey and the United States. Nine themes were identified and cluster into three groups: 1) Promoting prevention via early risk assessment, focusing on viral hepatitis and other lifestyle factors; 2) Increasing political, public and medical community awareness; and 3) Improving funding for screening, liver cancer surveillance and treatment.</p> <p>Conclusion</p> <p>This study is an important step towards developing an evidence-based approach to assessing preparedness for implementing comprehensive liver cancer control strategies. Evaluation mechanisms to assess countries' performance on the needs described are needed. Future research will concentrate of understanding how these needs vary across countries and the optimal strategies to improve the diagnosis and prognosis of patients with liver cancer internationally.</p

    Improved Measurement of the Pseudoscalar Decay Constant fDsf_{D_{s}}

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    We present a new determination of the Ds decay constant, f_{Ds} using 5 million continuum charm events obtained with the CLEO II detector. Our value is derived from our new measured ratio of widths for Ds -> mu nu/Ds -> phi pi of 0.173+/- 0.021 +/- 0.031. Taking the branching ratio for Ds -> phi pi as (3.6 +/- 0.9)% from the PDG, we extract f_{Ds} = (280 +/- 17 +/- 25 +/- 34){MeV}. We compare this result with various model calculations.Comment: 23 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

    Do citations and readership identify seminal publications?

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    This work presents a new approach for analysing the ability of existing research metrics to identify research which has strongly influenced future developments. More specifically, we focus on the ability of citation counts and Mendeley reader counts to distinguish between publications regarded as seminal and publications regarded as literature reviews by field experts. The main motivation behind our research is to gain a better understanding of whether and how well the existing research metrics relate to research quality. For this experiment we have created a new dataset which we call TrueImpactDataset and which contains two types of publications, seminal papers and literature reviews. Using the dataset, we conduct a set of experiments to study how citation and reader counts perform in distinguishing these publication types, following the intuition that causing a change in a field signifies research quality. Our research shows that citation counts work better than a random baseline (by a margin of 10%) in distinguishing important seminal research papers from literature reviews while Mendeley reader counts do not work better than the baseline

    First Observation of τ3πηντ\tau\to 3\pi\eta\nu_{\tau} and τf1πντ\tau\to f_{1}\pi\nu_{\tau} Decays

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    We have observed new channels for τ\tau decays with an η\eta in the final state. We study 3-prong tau decays, using the ηγγ\eta\to\gamma\gamma and \eta\to 3\piz decay modes and 1-prong decays with two \piz's using the ηγγ\eta\to\gamma\gamma channel. The measured branching fractions are \B(\tau^{-}\to \pi^{-}\pi^{-}\pi^{+}\eta\nu_{\tau}) =(3.4^{+0.6}_{-0.5}\pm0.6)\times10^{-4} and \B(\tau^{-}\to \pi^{-}2\piz\eta\nu_{\tau} =(1.4\pm0.6\pm0.3)\times10^{-4}. We observe clear evidence for f1ηππf_1\to\eta\pi\pi substructure and measure \B(\tau^{-}\to f_1\pi^{-}\nu_{\tau})=(5.8^{+1.4}_{-1.3}\pm1.8)\times10^{-4}. We have also searched for η(958)\eta'(958) production and obtain 90% CL upper limits \B(\tau^{-}\to \pi^{-}\eta'\nu_\tau)<7.4\times10^{-5} and \B(\tau^{-}\to \pi^{-}\piz\eta'\nu_\tau)<8.0\times10^{-5}.Comment: 11 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

    Postural control in 13-year-old soccer players

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    To evaluate the effect of early systematic soccer training on postural control we measured center-of-pressure (COP) variability, range, mean velocity and frequency in bipedal quiet stance with eyes open (EO) and closed (EC) in 44 boys aged 13 (25 boys who practiced soccer for 5–6 years and 19 healthy boys who did not practice sports). The soccer players had better stability, particularly in the medial–lateral plane (M/L); their COP variability and range were lower than in controls in both EO (p < 0.05) and EC (p < 0.0005) condition indicating that the athletes were less dependent on vision than non-athletes. Improved stability of athletes was accompanied by a decrease in COP frequency (p < 0.001 in EO, and p < 0.04 in EC) which accounted for lower regulatory activity of balance system in soccer players. The athletes had lower COP mean velocity than controls (p < 0.0001 in both visual condition), with larger difference in the M/L than A/P plane (p < 0.00001 and p < 0.05, respectively). Postural behavior was more variable within the non-athletes than soccer players, mainly in the EC stances (p < 0.005 for all COP parameters). We conclude that: (1) soccer training described was efficient in improving the M/L postural control in young boys; (2) athletes developed specific postural strategies characterized by decreased COP frequency and lower reliance on vision
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