12,667 research outputs found

    Axinos as Dark Matter

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    Supersymmetric extensions of the Standard Model that incorporate the axion solution to the strong CP problem necessarily contain also the axino, the fermionic partner of the axion. In contrast to the neutralino and the gravitino, the axino mass is generically not of the order of the supersymmetry-breaking scale and can be much smaller. The axino is therefore an intriguing candidate for a stable superpartner. In a previous Letter [1] it was shown that axinos are a natural candidate for cold dark matter in the Universe when they are generated non-thermally through out-of-equilibrium neutralino decays. Here, we extend the study of non-thermal production and include a competing thermal production mechanism through scatterings and decays of particles in the plasma. We identify axino masses in the range of tens of MeV to several GeV (depending on the scenario) as corresponding to cold axino relics if the reheating temperature \treh is less than about 5\times10^4\gev. At higher \treh and lower mass, axinos could constitute warm dark matter. In the scenario with axinos as relics, the gravitino problem finds a natural solution. The lightest superpartner of the Standard Model spectrum remains effectively stable in high-energy detectors but may be either neutral or charged. The usual highly restrictive constraint \abundchi\lsim1 on the relic abundance of the lightest neutralino becomes void.Comment: 38 pages, a version to be published at JHE

    Improving EMR Competency in First Year Nursing Students

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    Abstract Purpose: Competency in the nursing profession is a term many nurses are familiar with as it correlates to the ability to perform a task successfully. Nursing skills such as mixing insulin, giving an intramuscular injection, or taking manual blood pressure are all examples of skills evaluated during nursing school to determine the nursing students’ competency level. In addition to these nursing skills, informatics competency using an electronic medical record (EMR) should be assessed as well. The goal of the project is to gain significant insight for informatics curriculum development across and within undergraduate programs at a university in Southwest Georgia (SWGAU). Background: Currently, a new academic electronic medical record (AEMR) called Docucare has been initiated at SWGAU. Informatics competency skills checkoff on the new AEMR are not being assessed with first-year nursing students. Methods: Conceptual and theoretical frameworks were appraised to bring theory to practice implementing the proposed project. Patricia Benner’s Novice to Expert Theory and the Implementation Research Logic Model were analyzed and correlated to AEMR competency with first-year nursing students. The Plan Do Study Act method, along with the Tiger-based Assessment of Nursing Informatics Competencies (TANIC) tool were utilized to implement the simulation event. Results: The results of the project demonstrate the importance of informatics in nursing school and indicated a significant improvement after AEMR education in a simulation activity in first-year nursing students, especially related to the clinical data management area of focus. Conclusion: As technology changes in healthcare, it is vital academic settings should focus on improving informatics knowledge and competencies to guide nursing curriculum development

    A novel regulator of the p53-mediated mitochondrial apoptotic pathway

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    The p53 tumor suppressor protein induces apoptosis in response to genotoxic and environmental stress. Recent studies have revealed the existence of a transcription-independent mitochondrial p53 apoptosis pathway, however the mechanism regulating p53 translocation to mitochondria and subsequent initiation of apoptosis was not known. Here, we show that Tid1, also known as mtHsp40 or Dnaja3, interacts with p53 and directs its translocation to mitochondria in cells exposed to hypoxia. Overexpression of Tid1 in tumor cells promoted mitochondrial localization of both wildtype and mutant forms of p53 and was able to restore the pro-apoptotic activity of mutant p53 proteins that were otherwise unable to induce apoptosis. Tid1's mitochondrial signal sequence and DnaJ domain were both required for the movement of the p53-Tid1 complex from the cytosol to the mitochondria. Our findings establish Tid1 as a novel regulator of p53 localization and apoptotic function

    Gauge coupling Unification and SO(10) in 5D

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    We analyze the gauge unification in minimal supersymmetric SO(10) grand unified theories in 5 dimensions. The single extra spatial dimension is compactified on the orbifold S^1/(Z_2 x Z_2') reducing the gauge group to that of Pati-Salam SU(4)_c x SU(2)_L x SU(2)_R. The Standard Model gauge group is achieved by the further brane-localized Higgs mechanism on one of the fixed points. There are two main different approaches developed in literature. Higgs mechanism can take place on the Pati Salam brane, or on the SO(10) preserving brane. We show, both analytically and numerically, that in the first case a natural and succesfull gauge coupling unification can be achieved, while the second case is highly disfavoured. For completeness, we consider either the case in which the brane breaking scale is near the cutoff scale or the case in which it is lower than the compactification scale.Comment: 18 Pages and 8 PostScript Figure

    Stakeholder engagement in water governance as social learning: lessons from practice

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    The OECD Principles on Water Governance set out various requirements for stakeholder engagement. Coupled with conceptualizations of social learning, this article asks how we define and enact stakeholder engagement and explores the actual practice of engagement of stakeholders in three fields of water governance. The results suggest that a key consideration is the purpose of the stakeholder engagement, requiring consideration of its ethics, process, roles and expected outcomes. While facilitators cannot be held accountable if stakeholder engagement ‘fails’ in terms of social learning, they are responsible for ensuring that the enabling conditions for social learning are met

    Should YouTube’s Content ID Be Liable for Misrepresentation Under the Digital Millennium Copyright Act?

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    YouTube has quickly become the dominant player in the Internet video sharing platform market. To keep its leading position, it created an internal automated system to police potential copyright infringements known as Content ID. Generally, that system functions similarly to third-party computer automated systems that send takedown requests, yet it is exempt from liability for removing lawful videos under a safe harbor provided by the Digital Millennium Copyright Act of 1998 (“DMCA”). Although some industry experts first championed Content ID, many now question whether it unfairly favors copyright holders and YouTube itself at the expense of content creators and the greater Internet community. This Note asserts that a Content ID match is equivalent to a formal takedown notice under the DMCA, and that Content ID should thus have to consider fair use prior to issuing a Content ID match. This Note then argues that the DMCA’s safe harbor provisions should be amended to require websites utilizing internal automated systems to consider fair use

    Moonlight drives ocean-scale mass vertical migration of zooplankton during the Arctic winter

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    The creation of the pan-Arctic archive of ADCP data was supported by the UK Natural Environment Research Council (NERC) (Panarchive: NE/H012524/1 and SOFI: NE/F012381/1) as was mooring work in Svalbard (Oceans 2025 and Northern Sea Program). Moorings were also supported by the Research Council of Norway (NFR) projects: Circa (214271), Cleopatra (178766), Cleopatra II (216537), and Marine Night (226471).In extreme high-latitude marine environments that are without solar illumination in winter, light-mediated patterns of biological migration have historically been considered non-existent [1]. However, diel vertical migration (DVM) of zooplankton has been shown to occur even during the darkest part of the polar night, when illumination levels are exceptionally low [2 and 3]. This paradox is, as yet, unexplained. Here, we present evidence of an unexpected uniform behavior across the entire Arctic, in fjord, shelf, slope and open sea, where vertical migrations of zooplankton are driven by lunar illumination. A shift from solar-day (24-hr period) to lunar-day (24.8-hr period) vertical migration takes place in winter when the moon rises above the horizon. Further, mass sinking of zooplankton from the surface waters and accumulation at a depth of ∼50 m occurs every 29.5 days in winter, coincident with the periods of full moon. Moonlight may enable predation of zooplankton by carnivorous zooplankters, fish, and birds now known to feed during the polar night [4]. Although primary production is almost nil at this time, lunar vertical migration (LVM) may facilitate monthly pulses of carbon remineralization, as they occur continuously in illuminated mesopelagic systems [5], due to community respiration of carnivorous and detritivorous zooplankton. The extent of LVM during the winter suggests that the behavior is highly conserved and adaptive and therefore needs to be considered as “baseline” zooplankton activity in a changing Arctic ocean [6, 7, 8 and 9].Publisher PDFPeer reviewe

    Mapping current range with respect to abiotic site factors of selected southern oaks (Quercus spp) in Mississippi

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    Physical characteristics of a site that plant species inhabit may be useful in deriving the range of the species. Current range maps for tree species of the United States were originally developed by Elbert Little. These range maps were based primarily on observations. The purpose of this study was to update Little’s (Little, 1971) range maps of select southern oak species in Mississippi by calculating the topological, soil, and climatic features of sites using a Geographic Information System (GIS) to analyze environmental variables associated with species distributions. Data collected from databases were input into ArcMap and site data extracted using Hawth’s Analyst Tools. Stepwise logistic regression performed with site variables yielded the parameters used in predictive models to generate probability maps for each species across Mississippi. These probability maps demonstrate the potential to efficiently manage forests by giving a more encompassing view of species occurrence
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