6,353 research outputs found

    Study of Resistive Micromegas in a Mixed Neutron and Photon Radiation Field

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    The Muon ATLAS Micromegas Activity (MAMMA) focuses on the development and testing of large-area muon detectors based on the bulk-Micromegas technology. These detectors are candidates for the upgrade of the ATLAS Muon System in view of the luminosity upgrade of Large Hadron Collider at CERN (sLHC). They will combine trigger and precision measurement capability in a single device. A novel protection scheme using resistive strips above the readout electrode has been developed. The response and sparking properties of resistive Micromegas detectors were successfully tested in a mixed (neutron and gamma) high radiation field supplied by the Tandem accelerator, at the N.C.S.R. Demokritos in Athens. Monte-Carlo studies have been employed to study the effect of 5.5 MeV neutrons impinging on Micromegas detectors. The response of the Micromegas detectors on the photons originating from the inevitable neutron inelastic scattering on the surrounding materials of the experimental facility was also studied

    K^L_{mu3} decay: A first evidence of Right-Handed Quark Currents ?

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    The experimental results published by KTeV and the preliminary results from NA48 concerning the slope of the Kpi scalar form factor suggest a significant discrepancy with the prediction of the Callan-Treiman low energy theorem once interpreted within the Standard Model. In this talk, we will show how this discrepancy could be explained as a first evidence of the direct coupling of right-handed quarks to W as suggested by certain type of effective electroweak theories.Comment: 4 pages, 2 figures. Talk given at the 7th International Conference on Hyperons, Charm And Beauty Hadrons (BEACH 2006), 2-8 July 2006, Lancaster, U

    Assessing agricultural policy incentives for Greek organic agriculture: A Real options approach

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    The adoption of organic agriculture or livestock involves risk and uncertainty, and to overcome this, well designed schemes are required. Are the current support measures attractive for farmers who wish to convert to organic? At first, this study tries to assess the optimal investment trigger for a new comer into organic dairy sheep farming system and secondly, to evaluate the investment profitability of an existing organic farmer in his attempt to improve his farm. Results indicate that the framework of real options analysis is an appropriate form of analysis if the question of investment profitability is examined under risk and uncertainty and the role of economic subsidies offered to organic farmers is assessed.organic agriculture, dairy sheep farming, real options, agriculture policy, Agricultural and Food Policy, Farm Management, Land Economics/Use,

    Assessing economic incentives for dairy sheep farmers: A real options approach

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    New policy measures have been introduced to transform Greece’s agriculture into a more modern and environmentally friendly agriculture. Adopting new technology and environmentally friendly production systems involves risk and uncertainty, which in turn stress the need for well designed policy schemes. This study attempts to examine the effects of income variability upon the decision to adopt new technology and environmentally friendly production systems by introducing the real options analysis to dairy sheep farming in Greece. The real options procedure revealed that the investment in new technology in dairy sheep farms under organic scheme is profitable. Attractive economic incentives that are offered by the applied agricultural policy to young farmers compensate for the risk and uncertainty of the activity.agricultural policy, organic sheep farming, real options, Livestock Production/Industries,

    Policy implementations for organic agriculture: A real options approach

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    Organic farming has experienced a vast increase within the EU, despite the fact that it implies greater risk and uncertainty than that of conventional farming. This is the result of the increased environmental concern and the rising demand for quality food, which led to the implementation of the organic policy scheme. Nevertheless, the production of organic fruits, including cherries, is still limited in the EU. Farmers will adopt this alternative farming system only if the support provided by the existing policy regime out weights the increased risk and uncertainty. This study explores the effectiveness of the current policy measures for the production of organic cherries in Greece, using the real options methodology. The framework of real options analysis is an appropriate form of analysis so as to examine the investment’s profitability under risk and uncertainty and assess the economic incentives offered to organic farmers. The results indicate that the economic incentives provided by the existing policy regime, compensate for the risk and the uncertainty that farmers are undertaking. Furthermore, this study reveals that the profitability of the economic activity explored, lies mainly on the subsidies organic farmers receive.Keywords: organic agriculture, real options, agriculture policy, uncertainty, Agricultural and Food Policy, D81, Q14, Q18,

    MODELLING ECONOMIC ALTERNATIVES FOR TOBACCO PRODUCERS: THE CASE OF SHEEP FARMING

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    After the introduction of the new tobacco regime, many regions in Greece, formerly specialized in tobacco cultivation, are now facing serious threats of economic and social decline. Sheep farming is considered by many analysts as a viable alternative to tobacco. This study analyses the financial performance of sheep production and the risk that producers are taking. Through a stochastic efficiency analysis with respect to a function we explore the economic viability of conventional and organic sheep farming; key factors determining the economic outcome of these activities are also investigated. Both organic and conventional sheep farming appear as viable alternatives. The viability of organic farming lies, mainly, in organic payments. Conventional farming generates a slightly lower but less uncertain net return.organic farming, dairy sheep, risk analysis, SERF, agricultural policy, Agricultural and Food Policy, Farm Management, Livestock Production/Industries, Risk and Uncertainty,

    A Systematic Review of Randomized Controlled Interventions for Parents' Distress in Pediatric Leukemia

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    Objective. This review aims to summarize the existing evidence concerning interventions towards reducing stress in parents with a child with leukemia and their effect in child and family wellbeing. Methods. A systematic review strategy was conducted using MEDLINE covering the period January 1980 to June 2010. Results. Seven randomized controlled trials met the inclusion criteria including in total 1045 parents participants. A variety of cognitive-behavioral interventions problem-solving skills training programs have been used for managing distress in parents and children. Outcome measures are assessed by self-report, observer report, behavioral/psychological, and physiological measures. The most prominent methodological problems were the marked heterogeneity in stress measurement and the relative absence of proper measurement and adjustment of moderating and mediating factors. The largest effect has been obtained by combined cognitive-behavioral interventions with promising but limited evidence for several other psychological interventions. Conclusions. Recommendations for future RCTs are provided, and particular attention to the quality of trial design and reporting is highlighted

    Maternal pomegranate juice intake and brain structure and function in infants with intrauterine growth restriction: A randomized controlled pilot study.

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    Polyphenol-rich pomegranate juice has been shown to have benefit as a neuroprotectant in animal models of neonatal hypoxic-ischemia. No published studies have investigated maternal polyphenol administration as a potential neuroprotectant in at-risk newborns, such as those with intrauterine growth restriction (IUGR). This was a randomized, placebo-controlled, double-blind pilot study to investigate the impact of maternal pomegranate juice intake in pregnancies with IUGR, on newborn brain structure and function at term-equivalent age (TEA). Mothers with IUGR at 24-34 weeks\u27 gestation were recruited from Barnes-Jewish Hospital obstetrical clinic. Consented mothers were randomized to treatment (8 oz. pomegranate juice) or placebo (8 oz. polyphenol-free juice) and continued to take juice daily from enrollment until delivery (mean 20.1 and 27.1 days, respectively). Infants underwent brain MRI at TEA (36-41 weeks\u27 gestation). Brain measures were compared between groups including: brain injury score, brain metrics, brain volumes, diffusion tensor imaging and resting state functional connectivity. Statistical analyses were undertaken as modified intention-to-treat (including randomized participants who received their allocated intervention and whose infants received brain MRI) and per-protocol (including participants who strictly adhered to the protocol, based on metabolite status). Seventy-seven mothers were randomized to treatment (n = 40) or placebo (n = 37). Of these, 28 and 27 infants, respectively, underwent term-equivalent MRI. There were no group differences in brain injury, metrics or volumes. However, treatment subjects displayed reduced diffusivity within the anterior and posterior limbs of the internal capsule compared with placebo. Resting state functional connectivity demonstrated increased correlation and covariance within several networks in treatment subjects, with alterations most apparent in the visual network in per-protocol analyses. Direct effects on health were not found. In conclusion, maternal pomegranate juice intake in pregnancies with known IUGR was associated with altered white matter organization and functional connectivity in the infant brain, suggesting differences in brain structure and function following in utero pomegranate juice exposure, warranting continued investigation. Clinical trial registration. NCT00788866, registered November 11, 2008, initial participant enrollment August 21, 2012

    MR diffusion changes in the perimeter of the lateral ventricles demonstrate periventricular injury in post-hemorrhagic hydrocephalus of prematurity

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    OBJECTIVES: Injury to the preterm lateral ventricular perimeter (LVP), which contains the neural stem cells responsible for brain development, may contribute to the neurological sequelae of intraventricular hemorrhage (IVH) and post-hemorrhagic hydrocephalus of prematurity (PHH). This study utilizes diffusion MRI (dMRI) to characterize the microstructural effects of IVH/PHH on the LVP and segmented frontal-occipital horn perimeters (FOHP). STUDY DESIGN: Prospective study of 56 full-term infants, 72 very preterm infants without brain injury (VPT), 17 VPT infants with high-grade IVH without hydrocephalus (HG-IVH), and 13 VPT infants with PHH who underwent dMRI at term equivalent. LVP and FOHP dMRI measures and ventricular size-dMRI correlations were assessed. RESULTS: In the LVP, PHH had consistently lower FA and higher MD and RD than FT and VPT (p\u3c.050). However, while PHH FA was lower, and PHH RD was higher than their respective HG-IVH measures (p\u3c.050), the MD and AD values did not differ. In the FOHP, PHH infants had lower FA and higher RD than FT and VPT (p\u3c.010), and a lower FA than the HG-IVH group (p\u3c.001). While the magnitude of AD in both the LVP and FOHP were consistently less in the PHH group on pairwise comparisons to the other groups, the differences were not significant (p\u3e.050). Ventricular size correlated negatively with FA, and positively with MD and RD (p\u3c.001) in both the LVP and FOHP. In the PHH group, FA was lower in the FOHP than in the LVP, which was contrary to the observed findings in the healthy infants (p\u3c.001). Nevertheless, there were no regional differences in AD, MD, and RD in the PHH group. CONCLUSION: HG-IVH and PHH results in aberrant LVP/FOHP microstructure, with prominent abnormalities among the PHH group, most notably in the FOHP. Larger ventricular size was associated with greater magnitude of abnormality. LVP/FOHP dMRI measures may provide valuable biomarkers for future studies directed at improving the management and neurological outcomes of IVH/PHH
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