166 research outputs found

    Sensitivity plots for WIMP modulation searches

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    Prospects of WIMP searches using the annual modulation signature are discussed on statistical grounds, introducing sensitivity plots for the WIMP-nucleon scalar cross section.Comment: 3 pages, 2 figures, talk given at TAUP'99, september 199

    Sensitivity plots for WIMP direct detection using the annual modulation signature

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    Annual modulation due to the Earth's motion around the Sun is a well known signature of the expected WIMP signal induced in a solid state underground detector. In the present letter we discuss the prospects of this technique on statistical grounds, introducing annual-modulation sensitivity plots for the WIMP-nucleon scalar cross section for different materials and experimental conditions. The highest sensitivity to modulation is found in the WIMP mass interval 10 GeV< m_W < 130 GeV, the actual upper limit depending from the choice of the astrophysical parameters, while the lowest values of the explorable WIMP-nucleon elastic cross-sections fall in most cases within one order of magnitude of the sensitivities of present direct detection WIMP searches.Comment: 24 pages, ReVTeX, 9 figures, submitted to Astroparticle Physic

    Pulse Shape Discrimination in the IGEX Experiment

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    The IGEX experiment has been operating enriched germanium detectors in the Canfranc Underground Laboratory (Spain) in a search for the neutrinoless double decay of 76Ge. The implementation of Pulse Shape Discrimination techniques to reduce the radioactive background is described in detail. This analysis has been applied to a fraction of the IGEX data, leading to a rejection of ~60 % of their background, in the region of interest (from 2 to 2.5 MeV), down to ~0.09 c/(keV kg y).Comment: 18 pages, 10 figure

    New constraints on WIMPs from the Canfranc IGEX dark matter search

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    The IGEX Collaboration enriched 76Ge double-beta decay detectors are currently operating in the Canfranc Underground Laboratory with an overburden of 2450 m.w.e. A recent upgrade has made it possible to use them in a search for WIMPs. A new exclusion plot has been derived for WIMP-nucleon spin-independent interaction. To obtain this result, 30 days of data from one IGEX detector, which has an energy threshold of ~4 keV, have been considered. These data improve the exclusion limits derived from other germanium diode experiments in the ~50 GeV DAMA region, and show that with a moderate improvement of the background below 10 keV, the DAMA region may be tested with an additional 1 kg-year of exposure.Comment: 7 pages, 2 figures, submitted to Physics Letter

    Melatonin MT1 and MT2 receptors in the ram reproductive tract

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    Some melatonin functions in mammals are exerted through MT1 and MT2 receptors. However, there are no reports of their presence in the reproductive tract of the ram, a seasonal species. Thus, we have investigated their existence in the ram testis, epididymis, accessory glands and ductus deferens. Real-time polymerase chain reaction (qPCR) revealed higher levels of m-RNA for both receptors in the testis, ampulla, seminal vesicles, and vas deferens, than in the other organs of the reproductive tract (p < 0.05). Western blot analyses showed protein bands compatible with the MT1 in the testis and cauda epididymis, and for the MT2 in the cauda epididymis and deferent duct. Immunohistochemistry analyses revealed the presence of MT1 receptors in spermatogonias, spermatocytes, and spermatids, and MT2 receptors in the newly-formed spermatozoa in the testis, whereas both receptors were located in the epithelial cells of the ampulla, seminal vesicles, and ductus deferens. Indirect immunofluorescence showed significant differences in the immunolocation of both receptors in spermatozoa during their transit in the epididymis. In conclusion, it was demonstrated that melatonin receptors are present in the ram reproductive tract. These results open the way for new studies on the molecular mechanism of melatonin and the biological significance of its receptors

    Variability and evolution of acute myocardial infarction management in the PRIMVAC Study (Acute myocardial infarction register of Valencia, Alicante and Castellón)

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    En España existe escasa información sobre la variabilidad interhospitalaria en el tratamiento del infarto agudo de miocardio (IAM) y su evolución temporal. El objetivo de este trabajo es describir el coeficiente de variabilidad (CV) y su evolución en la utilización de trombolíticos, aspirina (AAS), bloqueadores beta e inhibidores de la enzima conversiva de la angiotensina (IECA) en los hospitales del registro PRIMVAC.Data about hospital differences in acute myocardial infarction (AMI) management are scarce in Spain. The aim of this study is to describe the variability in the use of thrombolytic therapy, aspirine (AAS), beta-blockers and angiotensin converting enzyme inhibitors (ACEI) in the management of AMI, and the changes observed along a 4-year period among 12 hospitals participating in the PRIMVAC registry.Medicin

    Melatonin receptors MT1 and MT2 are expressed in spermatozoa from several seasonal and nonseasonal breeder species

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    P. 1958-1968Melatonin is a ubiquitous and multipurpose molecule, and one of its roles is to regulate reproduction in some seasonal mammals. Our group has previously reported the variation in the melatonin levels in ram seminal plasma along the year and identified MT1 and MT2 receptors in ram spermatozoa. The objective of this study was to elucidate whether the presence of melatonin receptors (MT1 and MT2) in the sperm plasma membrane, and melatonin in the seminal plasma is related to seasonal breeding. For this purpose, the presence of melatonin receptors and the levels of melatonin in seminal plasma have been examined in several species: donkey and stallion as long-day breeders; red deer as a wild, short-day, highly seasonal breeder (epididymal spermatozoa); bull as a conventional nonseasonal breeder; boar as a seasonal breeder under management techniques; and dog as possible a seasonal breeder not regulated by melatonin. We have detected measurable levels of melatonin in the seminal plasma of all ejaculated semen samples (from donkey, stallion, boar, bull, and dog). Also, and for the first time, we have demonstrated the presence of MT1 and MT2 melatonin receptors in the spermatozoa of all these species, regardless their type of reproduction or sperm source (ejaculated or epididymal), using indirect immunofluorescence techniques and Western blotting. Our findings suggest that melatonin and melatonin receptors may be universally distributed in the reproductive system of mammals and that the sperm melatonin receptors cells may not be necessarily related with seasonal reproduction. Furthermore, the presence of MT1 at the cytoplasmic droplet in immature ejaculated stallion spermatozoa found in one sample and epididymal red deer spermatozoa suggests that melatonin may be involved in specific functions during spermatogenesis and sperm maturation, like protecting spermatozoa from oxidative damage, this activity being mediated through these receptors.S
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