541 research outputs found

    Construction of a highly enriched marsupial Y chromosome-specific BAC sub-library using isolated Y chromosomes

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    The Y chromosome is perhaps the most interesting element of the mammalian genome but comparative analysis of the Y chromosome has been impeded by the difficulty of assembling a shotgun sequence of the Y. B AC-based sequencing has been successful for the human and chimpanzee Y but is difficult to do efficiently for an atypical mammalian model species (Skaletsky et al. 2003, Kuroki et al. 2006). We show how Y-specific sub-libraries can be efficiently constructed using DNA amplified from microdissected or flow-sorted Y chromosomes. A Bacterial Artificial Chromosome (BAC) library was constructed from the model marsupial, the tammar wallaby (Macropus eugenii). We screened this library for Y chromosome-derived BAC clones using DNA from both a microdissected Y chromosome and a flow-sorted Y chromosome in order to create a Y chromosome-specific sub-library. We expected that the tammar wallaby Y chromosome should detect ∼100 clones from the 2.2 times redundant library. The microdissected Y DNA detected 85 clones, 82% of which mapped to the Y chromosome and the flow-sorted Y DNA detected 71 clones, 48% of which mapped to the Y chromosome. Overall, this represented a ∼330-fold enrichment for Y chromosome clones. This presents an ideal method for the creation of highly enriched chromosome-specific sub-libraries suitable for BAC-based sequencing of the Y chromosome of any mammalian species

    Foundation and empire : a critique of Hardt and Negri

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    In this article, Thompson complements recent critiques of Hardt and Negri's Empire (see Finn Bowring in Capital and Class, no. 83) using the tools of labour process theory to critique the political economy of Empire, and to note its unfortunate similarities to conventional theories of the knowledge economy

    Weak Interaction Studies with 6He

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    The 6He nucleus is an ideal candidate to study the weak interaction. To this end we have built a high-intensity source of 6He delivering ~10^10 atoms/s to experiments. Taking full advantage of that available intensity we have performed a high-precision measurement of the 6He half-life that directly probes the axial part of the nuclear Hamiltonian. Currently, we are preparing a measurement of the beta-neutrino angular correlation in 6He beta decay that will allow to search for new physics beyond the Standard Model in the form of tensor currents.Comment: 5 pages, 4 figures, proceedings for the Eleventh Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2012

    Enhancing resident scholarship with a library partnership.

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    Introduction: The ACGME requires that residents understand and participate in scholarly activities in order to meet graduation requirements. Although library support had historically been available to residents, there was no evidence that this resource was utilized in the past. The Family Medicine residency utilizes the library partnership in order to educate residents about the most effective methods to search for relevant literature and provide residents with an overview of pertinent library resources, including how to access full-text articles. A couple of years ago, the presenters developed a curriculum to provide residents with education on library resources, so that residents could effectively complete their scholarly activities by utilizing evidence-based literature. Study Objective: The study objective was to gather data from residents who have received education on IUSM library resources in order to describe what residents learned and what they identify are future educational needs. Methods: During 2 academic years, 23 second-year residents attended a one-hour library instruction session while on their scholarship rotation. Thirteen residents attended a session during October – February of the first academic year, and 10 residents attended a session during August – November of the second academic year. The goals for the session were that residents would: learn the basics of searching for literature on a topic, become familiar with library resources, and begin searching for literature related to their individual scholarly projects. This cross-sectional study used an 8-question survey given to all second and third-year residents at the end of the second year that the library instruction sessions were implemented. Results: Thirteen of the 23 residents responded to the survey (57%). Five of the respondents (38%) were second-year residents, and 8 of the respondents (62%) were third-year residents. All 13 residents responded that they learned about library resources during the session, and 11 residents said they learned the basics of searching for literature on a topic. Eight residents responded that they learned how to get access to full-text articles. Seven residents also responded that having a second session after the project is further along would be useful to them, and 6 residents responded that citation information would be useful for the librarians to cover. Conclusions: Results of the cross-sectional survey indicated that the goal of increasing residents' knowledge about library resources was met. As a result of the library instruction, residents used what they learned when searching for articles and when accessing the full-text of articles. Feedback from the survey suggested that an additional session and more instruction on citation information would be helpful. Future scholarship sessions will be modified to include an introduction to citation management software, and an additional session will be scheduled during the third core to focus more in-depth on citation management software, keyword searching, and any other questions residents may have. Pre-& post-tests to evaluate residents' change in confidence when literature searching and managing citations during their scholarly project will be implemented

    Human resource management–well‐being–performance research revisited:Past, present, and future

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    The authors provide an up‐to‐date theoretically based qualitative review of research dealing with the relationship between HRM, employee well‐being, and individual/organisational performance (HRM‐WB‐IOP research). The review is based on a systematic critical analysis of all HRM‐WB‐IOP studies (N = 46) published in 13 core HRM and management journals in the 2000 to 2018 period. The authors first identify different theoretical models of the HRM‐WB‐IOP relationship, which they then use to map research in the area. The results show that mutual gains conceptualisations play a dominant role in extant HRM‐WB‐IOP research, at the expense of alternative conflicting outcomes and mutual losses models, which are also shown to receive very limited empirical support across the 46 studies. As part of this mapping exercise, the authors identify important knowledge gaps in the area and conclude by setting out a number of key recommendations for future research to address these gaps

    Precision Measurement of the 6He Half-Life and the Weak Axial Current in Nuclei

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    Studies of 6He beta decay along with tritium can play an important role in testing ab-initio nuclear wave-function calculations and may allow for fixing low-energy constants in effective field theories. Here, we present an improved determination of the 6He half-life to a relative precision of 3x10^(-4). Our value of 806.89 \pm 0.11(stat)^{+0.23}_{-0.19}(syst) ms resolves a major discrepancy between previous measurements. Calculating the statistical rate function we determined the ft-value to be 803.04 ^{+0.26}_{-0.23} s. The extracted Gamow-Teller matrix element agrees within a few percent with ab-initio calculations.Comment: 5 pages, 2 figures, published in Physical Review Letter

    Precision Measurement of the 6He Half-Life and the Weak Axial Current in Nuclei

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    Background: The β decays of 3H and 6He can play an important role in testing nuclear wave-function calculations and fixing low-energy constants in effective-field theory approaches. However, there exists a large discrepancy between previous measurements of the 6He half-life. Purpose: Our measurement aims at resolving this long-standing discrepancy in the 6He half-life and providing a reliable ft value and Gamow-Teller matrix element for comparison with theoretical ab initio calculations. Method: We measured the 6He half-life by counting the β-decay electrons with two scintillator detectors operating in coincidence. Results: The measured 6He half-life is 806.89±0.11 stat-0.19+0.23syst ms corresponding to a relative precision of 3×10-4. Calculating the statistical rate function we determined the ft value to be 803.04-0.23+0.26 s. Conclusions: Our result resolves the previous discrepancy by providing a higher-precision result with careful analysis of potential systematic uncertainties. The result provides a reliable basis for future precision comparisons with ab initio calculations. © 2012 American Physical Society

    Use of a radiopaque localizer grid to reduce radiation exposure

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    Abstract Background Minimally invasive spine surgery requires placement of the skin incision at an ideal location in the patient's back by the surgeon. However, numerous fluoroscopic x-ray images are sometimes required to find the site of entry, thereby exposing patients and Operating Room personnel to additional radiation. To minimize this exposure, a radiopaque localizer grid was devised to increase planning efficiency and reduce radiation exposure. Results The radiopaque localizer grid was utilized to plan the point of entry for minimally invasive spine surgery. Use of the grid allowed the surgeon to accurately pinpoint the ideal entry point for the procedure with just one or two fluoroscopic X-ray images. Conclusions The reusable localizer grid is a simple and practical device that may be utilized to more efficiently plan an entry site on the skin, thus reducing radiation exposure. This device or a modified version may be utilized for any procedure involving the spine

    Surgery alone for papillary thyroid microcarcinoma is less costly and more effective than long term active surveillance

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    Background: Papillary thyroid microcarcinoma is a subtype of thyroid cancer that may be managed with active surveillance rather than immediate surgery. Active surveillance decreases complication rates and may decrease health care costs. This study aims to analyze complication rates of thyroid surgery, papillary thyroid microcarcinoma recurrence, and survival rates. Additionally, the costs of surgery versus hypothetic active surveillance for papillary thyroid microcarcinoma are compared in an Australian cohort. Methods: Papillary thyroid microcarcinoma patients were included from a prospectively collected surgical cohort of patients treated for papillary thyroid cancer between 1985 and 2017. The primary outcomes were the complications of thyroid surgery, recurrence-free survival, overall survival, and cost of surgical treatment and active surveillance. Results: In a total of 349 patients with papillary microcarcinoma with a median age of 48 years (range, 18–90 years), the permanent operative complications rate was 3.7%. Postoperative radioactive iodine did not decrease recurrence-free survival (P = .3). The total cost of surgical treatment was 10,226Australiandollars,whereashypotheticactivesurveillancewasatayearlycostof10,226 Australian dollars, whereas hypothetic active surveillance was at a yearly cost of 756 Australian dollars. Estimated cost of surgical papillary thyroid microcarcinoma treatment was equivalent to the cost of 16.2 years of active surveillance. Conclusion: Surgery may have a long-term economic advantage for younger Australian patients with papillary thyroid microcarcinoma who are likely to require more than 16.2 years of follow-up in an active surveillance scheme
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