926 research outputs found

    Pork Carcass Composition as Influenced by Slaughter Weight

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    The common goal for those engaged in producing and processing pork should be the efficient production of a product which ultimately is highly desirable to the consumer. This means that any retail pork item must be lean, attractive to the eye and yet be very tasty. This study, concerned with changes in body composition, is a portion of a larger project concerned with more efficient production and utilization of pork

    Supply Risk Considerations for the Elements in Nickel-Based Superalloys

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    Nickel-based superalloys contain various elements which are added in order to make the alloys more resistant to thermal and mechanical stress and to the adverse operating environments in jet engines. In particular, higher combustion temperatures in the gas turbine are important, since they result in higher fuel efficiency and thus in lower CO2 emissions. In this paper, a semi-quantitative assessment scheme is used to evaluate the relative supply risks associated with elements contained in various Ni-based superalloys: aluminium, titanium, chromium, iron, cobalt, niobium, molybdenum, ruthenium, tantalum, tungsten, and rhenium. Twelve indicators on the elemental level and four aggregation methods are applied in order to obtain the supply risk at the alloy level. The supply risks for the elements rhenium, molybdenum and cobalt are found to be the highest. For three of the aggregation schemes, the spread in supply risk values for the different alloy types (as characterized by chemical composition and the endurance temperature) is generally narrow. The fourth, namely the cost-share’ aggregation scheme, gives rise to a broader distribution of supply risk values. This is mainly due to the introduction of rhenium as a component starting with second-generation single crystal alloys. The resulting higher supply risk appears, however, to be acceptable for jet engine applications due to the higher temperatures these alloys can endur

    Flight and Integrated Testing: Blazing the Trail for the Ares Launch Vehicles

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    It has been 30 years since the United States last designed and built a human-rated launch vehicle. The National Aeronautics and Space Administration (NASA) has marshaled unique resources from the government and private sectors that will carry the next generation of astronauts into space safer and more efficiently than ever and send them to the Moon to develop a permanent outpost. NASA's Flight and Integrated Test Office (FITO) located at Marshall Space Flight Center and the Ares I-X Mission Management Office have primary responsibility for developing and conducting critical ground and flight tests for the Ares I and Ares V launch vehicles. These tests will draw upon Saturn and the Space Shuttle experiences, which taught the value of using sound systems engineering practices, while also applying aerospace best practices such as "test as you fly" and other lessons learned. FITO will use a variety of methods to reduce the technical, schedule, and cost risks of flying humans safely aboard a launch vehicle

    Molecular details of quinolone–DNA interactions: solution structure of an unusually stable DNA duplex with covalently linked nalidixic acid residues and non-covalent complexes derived from it

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    Quinolones are antibacterial drugs that are thought to bind preferentially to disturbed regions of DNA. They do not fall into the classical categories of intercalators, groove binders or electrostatic binders to the backbone. We solved the 3D structure of the DNA duplex (ACGCGU-NA)(2), where NA denotes a nalidixic acid residue covalently linked to the 2′-position of 2′-amino-2′-deoxyuridine, by NMR and restrained torsion angle molecular dynamics (MD). In the complex, the quinolones stack on G:C base pairs of the core tetramer and disrupt the terminal A:U base pair. The displaced dA residues can stack on the quinolones, while the uracil rings bind in the minor groove. The duplex-bridging interactions of the drugs and the contacts of the displaced nucleotides explain the high UV-melting temperature for d(ACGCGU-NA)(2) of up to 53°C. Further, non-covalently linked complexes between quinolones and DNA of the sequence ACGCGT can be generated via MD using constraints obtained for d(ACGCGU-NA)(2). This is demonstrated for unconjugated nalidixic acid and its 6-fluoro derivative. The well-ordered and tightly packed structures thus obtained are compatible with a published model for the quinolone–DNA complex in the active site of gyrases

    Crystal-clear neuronal computing

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    Induced progressive crystallization in chalcogenide-based materials can be used to closely mimic neuronal functions, opening new paths to neuromorphic computing

    Two-Color Laser Speckle Shift Strain Measurement System

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    A two color laser speckle shift strain measurement system based on the technique of Yamaguchi was designed. The dual wavelength light output from an Argon Ion laser was coupled into two separate single-mode optical fibers (patchcords). The output of the patchcords is incident on the test specimen (here a structural fiber). Strain on the fiber, in one direction, is produced using an Instron 4502. Shifting interference patterns or speckle patterns will be detected at real-time rates using 2 CCD cameras with image processing performed by a hardware correlator. Strain detected in fibers with diameters from 21 microns to 143 microns is expected to be resolved to 15 mu epsilon. This system was designed to be compact and robust and does not require surface preparation of the structural fibers

    Mechanochemical action of the dynamin protein

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    Dynamin is a ubiquitous GTPase that tubulates lipid bilayers and is implicated in many membrane severing processes in eukaryotic cells. Setting the grounds for a better understanding of this biological function, we develop a generalized hydrodynamics description of the conformational change of large dynamin-membrane tubes taking into account GTP consumption as a free energy source. On observable time scales, dissipation is dominated by an effective dynamin/membrane friction and the deformation field of the tube has a simple diffusive behavior, which could be tested experimentally. A more involved, semi-microscopic model yields complete predictions for the dynamics of the tube and possibly accounts for contradictory experimental results concerning its change of conformation as well as for plectonemic supercoiling.Comment: 17 pages, 4 figures; typos corrected, reference adde

    Healthcare Providers Knowledge, Attitudes, and Beliefs Toward the CALM Coping Scale

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    Background: One of the most effective ways to diagnose and treat laboring women’s breakthrough pain is to use a high-quality pain scale. The antiquated 0-10 numeric pain scale does not adequately assess laboring women’s pain, as zero is not a realistic pain score during labor. The CALM coping scale is an algorithm and a numeric scale with multiple categories to allow the healthcare staff to evaluate whether the laboring woman is coping or not coping. This scale is not well known but has improved laboring women's pain management.Purpose: This project aims to discover the knowledge, attitudes, and beliefs of healthcare providers working in a labor and delivery unit regarding the CALM coping scale.Methods: A computer-based pre-survey was distributed to assess healthcare providers’ knowledge, attitudes, and beliefs regarding the CALM coping scale. After completing the pre-survey, the healthcare providers were provided an education in-service on the CALM coping scale. A follow-up post-survey was administered after using the scale for a total of 3 months.Setting: An 18-bed labor and delivery unit at a women and children’s hospital located in central North Carolina. Participants: A sample of 60 healthcare providers of the 114 who work in the project’s labor and delivery unit. Results: Most providers were unfamiliar with the CALM coping scale, but agreed they are more likely to use the CALM coping scale versus the numeric pain scale, due to its accuracy. Providers perceived patients complained of less pain when using the CALM coping scale, and narcotic use was decreased. Nonpharmacologic pain relief methods included emotional support, position changes, and a calm environment. Recommendations and Conclusion: It is essential to understand providers' knowledge, attitudes, and beliefs regarding the CALM coping scale to implement a plan that ensures providers will adhere to this scale within their everyday practice. Frequent in-services addressing current pain management strategies are imperative. Future practice recommendations include conducting this project on a larger scale

    Structural basis of rotavirus RNA chaperone displacement and RNA annealing.

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    Rotavirus genomes are distributed between 11 distinct RNA molecules, all of which must be selectively copackaged during virus assembly. This likely occurs through sequence-specific RNA interactions facilitated by the RNA chaperone NSP2. Here, we report that NSP2 autoregulates its chaperone activity through its C-terminal region (CTR) that promotes RNA-RNA interactions by limiting its helix-unwinding activity. Unexpectedly, structural proteomics data revealed that the CTR does not directly interact with RNA, while accelerating RNA release from NSP2. Cryo-electron microscopy reconstructions of an NSP2-RNA complex reveal a highly conserved acidic patch on the CTR, which is poised toward the bound RNA. Virus replication was abrogated by charge-disrupting mutations within the acidic patch but completely restored by charge-preserving mutations. Mechanistic similarities between NSP2 and the unrelated bacterial RNA chaperone Hfq suggest that accelerating RNA dissociation while promoting intermolecular RNA interactions may be a widespread strategy of RNA chaperone recycling

    Estimated Risk of HIV Acquisition and Practice for Preventing Occupational Exposure: A Study of Healthcare Workers at Tumbi and Dodoma Hospitals, Tanzania.

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    Health care workers (HCWs) are at risk of acquiring human immuno-deficiency virus (HIV) and other infections via exposure to infectious patients' blood and body fluids. The main objective of this study was to estimate the risk of HIV transmission and examine the practices for preventing occupational exposures among HCWs at Tumbi and Dodoma Hospitals in Tanzania. This study was carried out in two hospitals, namely, Tumbi in Coast Region and Dodoma in Dodoma Region. In each facility, hospital records of occupational exposure to HIV infection and its management were reviewed. In addition, practices to prevent occupational exposure to HIV infection among HCWs were observed. The estimated risk of HIV transmission due to needle stick injuries was calculated to be 7 cases per 1,000,000 HCWs-years. Over half of the observed hospital departments did not have guidelines for prevention and management of occupational exposure to HIV infections and lacked well displayed health and safety instructions. Approximately, one-fifth of the hospital departments visited failed to adhere to the instructions pertaining to correlation between waste materials and the corresponding colour coded bag/container/safety box. Seventy four percent of the hospital departments observed did not display instructions for handling infectious materials. Inappropriate use of gloves, lack of health and safety instructions, and lack of use of eye protective glasses were more frequently observed at Dodoma Hospital than at Tumbi Hospital. The poor quality of the hospital records at the two hospitals hampered our effort to characterise the risk of HIV infection acquisition by HCWs. Greater data completeness in hospital records is needed to allow the determination of the actual risk of HIV transmission for HCWs. To further reduce the risk of HIV infection due to occupational exposure, hospitals should be equipped with sufficient personal protective equipment (PPE) and HCWs should be reminded of the importance of adhering to universal precautions
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