146 research outputs found

    Ricci Flow Gravity

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    A theory of gravitation is proposed, modeled after the notion of a Ricci flow. In addition to the metric an independent volume enters as a fundamental geometric structure. Einstein gravity is included as a limiting case. Despite being a scalar-tensor theory the coupling to matter is different from Jordan-Brans-Dicke gravity. In particular there is no adjustable coupling constant. For the solar system the effects of Ricci flow gravity cannot be distinguished from Einstein gravity and therefore it passes all classical tests. However for cosmology significant deviations from standard Einstein cosmology will appear.Comment: 15 pages. V2: improved presentation, in particular Jordan vs. Brans-Dicke and on viability. Added section on physical interpretation. V3: more references. Reworked to agree with published versio

    Choice of psychological coping in laryngectomized, head and neck squamous cell carcinoma patients versus multiple sclerosis patients

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    To be treated for cancer must be a frightening experience. Yet quality of life (QoL) of successfully treated cancer patients seems to be relatively similar in comparison with QoL of a general population, with psychological coping partly responsible for this finding. When measuring choice of coping, the nature of coping score levels constituting appropriate scores, and whether score levels rely on the context of the disease has not been settled. We have studied the COPE coping responses as related to disease in successfully treated head and neck squamous cell carcinoma (HNSCC) patient groups (general and laryngectomized), as well as compared to multiple sclerosis (MS) patients. The COPE response patterns have also been compared to the Beck depression inventory (BDI) scores. Age and gender of patients were not directly associated with choice of coping. Within the problem-focused coping indexes, the coping index “active coping” was reported to be most utilized among HNSCC patients, whereas “coping by suppression” and “coping by social support” were most utilized among MS patients. Emotional-focused coping was most prevalent among HNSCC patients and lowest among the MS patients. Level of avoidance coping was similar between the groups. The coping of the general HNSCC patients differed most from the MS patients. An association was shown between increased coping efforts and lowered mood. In particular, avoidance coping was associated with lowered mood. These associations were stronger among the MS patients than HNSCC patients. Drinking to cope was most prevalent among the laryngectomized group, and was correlated with BDI scores in all groups. Furthermore, adequate coping seems to be to limit avoidance coping and promote coping by acceptance. The response pattern of the COPE inventory seems to be valid among HNSCC and MS patients

    Cruel to be kind but not cruel for cash : harm aversion in the dictator game

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    People regularly take prosocial actions, making individual sacrifices for the greater good. Similarly, people generally avoid causing harm to others. These twin desires to do good and avoid harm often align, but sometimes they can diverge, creating situations of moral conflict. Here, we examined this moral conflict using a modified dictator game. Participants chose how much money to allocate away from a recipient who was designated as an orphan, creating a sense of harm. This money was then reallocated to either the participant or a charity. People were strongly prosocial: they allocated more money away from the orphan for charity than for themselves. Furthermore, people left more money with the orphan when the harm was framed as a means (taking) than as a side effect (splitting). As is predicted by dual-process theories of moral decision making, response times were longer with the take action and were positively correlated with the amount taken from the orphan. We concluded that just as people take positive actions for the greater good, they are similarly more willing to cause harm when it benefits others rather than themselves

    Going means trouble and staying makes it double: the value of licensing recorded music online

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    This paper discusses whether a copyright compensation system (CCS) for recorded music—endowing private Internet subscribers with the right to download and use works in return for a fee—would be welfare increasing. It reports on the results of a discrete choice experiment conducted with a representative sample of the Dutch population consisting of 4986 participants. Under some conservative assumptions, we find that applied only to recorded music, a mandatory CCS could increase the welfare of rights holders and users in the Netherlands by over €600 million per year (over €35 per capita). This far exceeds current rights holder revenues from the market of recorded music of ca. €144 million per year. A monthly CCS fee of ca. €1.74 as a surcharge on Dutch Internet subscriptions would raise the same amount of revenues to rights holders as the current market for recorded music. With a voluntary CCS, the estimated welfare gains to users and rights holders are even greater for CCS fees below €20 on the user side. A voluntary CCS would also perform better in the long run, as it could retain a greater extent of market coordination. The results of our choice experiment indicate that a well-designed CCS for recorded music would simultaneously make users and rights holders better off. This result holds even if we correct for frequently observed rates of overestimation in contingent valuation studies

    Reviewing the evidence on effectiveness and cost-effectiveness of HIV prevention strategies in Thailand

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    <p>Abstract</p> <p>Background</p> <p>Following universal access to antiretroviral therapy in Thailand, evidence from National AIDS Spending Assessment indicates a decreasing proportion of expenditure on prevention interventions. To prompt policymakers to revitalize HIV prevention, this study identifies a comprehensive list of HIV/AIDs preventive interventions that are likely to be effective and cost-effective in Thailand.</p> <p>Methods</p> <p>A systematic review of the national and international literature on HIV prevention strategies from 1997 to 2008 was undertaken. The outcomes used to consider the effectiveness of HIV prevention interventions were changes in HIV risk behaviour and HIV incidence. Economic evaluations that presented their results in terms of cost per HIV infection averted or cost per quality-adjusted life year (QALY) gained were also included. All studies were assessed against quality criteria.</p> <p>Results</p> <p>The findings demonstrated that school based-sex education plus life-skill programs, voluntary and routine HIV counselling and testing, male condoms, street outreach programs, needle and syringe programs, programs for the prevention of mother-to-child HIV transmission, male circumcision, screening blood products and donated organs for HIV, and increased alcohol tax were all effective in reducing HIV infection among target populations in a cost-effective manner.</p> <p>Conclusion</p> <p>We found very limited local evidence regarding the effectiveness of HIV interventions amongst specific high risk populations. This underlines the urgent need to prioritise health research resources to assess the effectiveness and cost-effectiveness of HIV interventions aimed at reducing HIV infection among high risk groups in Thailand.</p

    The authority of next-of-kin in explicit and presumed consent systems for deceased organ donation: an analysis of 54 nations

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    Background. The degree of involvement by the next-of-kin in deceased organ procurement worldwide is unclear. We investigated the next-of-kin’s authority in the procure-ment process in nations with either explicit or presumed consent. Methods. We collected data from 54 nations, 25 with presumed consent and 29 with explicit consent. We char-acterized the authority of the next-of-kin in the decision to donate deceased organs. Specifically, we examined whether the next-of-kin’s consent to procure organs was always required and whether the next-of-kin were able to veto procurement when the deceased had expressed a wish to donate. Results. The next-of-kin are involved in the organ procure-ment process in most nations regardless of the consent principle and whether the wishes of the deceased to be a donor were expressed or unknown. Nineteen of the 25 nations with presumed consent provide a method for individuals to express a wish to be a donor. However, health professionals in only four of these nations responded that they do not override a deceased’s expressed wish because of a family’s objection. Similarly, health profes-sionals in only four of the 29 nations with explicit consent proceed with a deceased’s pre-existing wish to be a donor and do not require next-of-kin’s consent, but caveats still remain for when this is done. Conclusions. The next-of-kin have a considerable influ-ence on the organ procurement process in both presumed and explicit consent nations

    Bacteria-inducing legume nodules involved in the improvement of plant growth, health and nutrition

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    Bacteria-inducing legume nodules are known as rhizobia and belong to the class Alphaproteobacteria and Betaproteobacteria. They promote the growth and nutrition of their respective legume hosts through atmospheric nitrogen fixation which takes place in the nodules induced in their roots or stems. In addition, rhizobia have other plant growth-promoting mechanisms, mainly solubilization of phosphate and production of indoleacetic acid, ACC deaminase and siderophores. Some of these mechanisms have been reported for strains of rhizobia which are also able to promote the growth of several nonlegumes, such as cereals, oilseeds and vegetables. Less studied are the mechanisms that have the rhizobia to promote the plant health; however, these bacteria are able to exert biocontrol of some phytopathogens and to induce the plant resistance. In this chapter, we revised the available data about the ability of the legume nodule-inducing bacteria for improving the plant growth, health and nutrition of both legumes and nonlegumes. These data showed that rhizobia meet all the requirements of sustainable agriculture to be used as bio-inoculants allowing the total or partial replacement of chemicals used for fertilization or protection of crops

    A New Limit on CMB Circular Polarization from SPIDER

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    We present a new upper limit on cosmic microwave background (CMB) circular polarization from the 2015 flight of Spider, a balloon-borne telescope designed to search for B-mode linear polarization from cosmic inflation. Although the level of circular polarization in the CMB is predicted to be very small, experimental limits provide a valuable test of the underlying models. By exploiting the nonzero circular-to-linear polarization coupling of the half-wave plate polarization modulators, data from Spider's 2015 Antarctic flight provide a constraint on Stokes V at 95 and 150 GHz in the range 33<<30733\lt {\ell }\lt 307. No other limits exist over this full range of angular scales, and Spider improves on the previous limit by several orders of magnitude, providing 95% C.L. constraints on (+1)CVV/(2π){\ell }({\ell }+1){C}_{{\ell }}^{{VV}}/(2\pi ) ranging from 141 to 255 μK2 at 150 GHz for a thermal CMB spectrum. As linear CMB polarization experiments become increasingly sensitive, the techniques described in this paper can be applied to obtain even stronger constraints on circular polarization
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