6,774 research outputs found
Electromagnetic Radiation Hardness of Diamond Detectors
The behavior of artificially grown CVD diamond films under intense
electromagnetic radiation has been studied. The properties of irradiated
diamond samples have been investigated using the method of thermally stimulated
current and by studying their charge collection properties. Diamonds have been
found to remain unaffected after doses of 6.8 MGy of 10 keV photons and 10 MGy
of MeV-range photons. This observation makes diamond an attractive detector
material for a calorimeter in the very forward region of the proposed TESLA
detector.Comment: 19 pages, 9 figure
Possible Single Resonant Production of the Fourth Generation Charged Leptons at Colliders
Single resonant productions of the fourth standard model generation charged
lepton via anomalous interactions at gamma e colliders based on future linear
e^+ e^- colliders with 500 GeV and 1 TeV center of mass energies are studied.
Signatures of and
anomalous processes followed by the hadronic and leptonic decay of the Z boson
and corresponding standard model backgrounds are discussed in details. The
lowest necessary luminosities to observe these processes and the achievable
values of the anomalous coupling strengths are determined.Comment: 9 pages, 6 figures, 4 table
Polyparasitism with Schistosoma haematobium and soil-transmitted helmith infections among school children in Loum, Cameroon (vol 8, pg 975, 2003)
Human hypocretin and melanin-concentrating hormone levels are linked to emotion and social interaction.
The neurochemical changes underlying human emotions and social behaviour are largely unknown. Here we report on the changes in the levels of two hypothalamic neuropeptides, hypocretin-1 and melanin-concentrating hormone, measured in the human amygdala. We show that hypocretin-1 levels are maximal during positive emotion, social interaction and anger, behaviours that induce cataplexy in human narcoleptics. In contrast, melanin-concentrating hormone levels are minimal during social interaction, but are increased after eating. Both peptides are at minimal levels during periods of postoperative pain despite high levels of arousal. Melanin-concentrating hormone levels increase at sleep onset, consistent with a role in sleep induction, whereas hypocretin-1 levels increase at wake onset, consistent with a role in wake induction. Levels of these two peptides in humans are not simply linked to arousal, but rather to specific emotions and state transitions. Other arousal systems may be similarly emotionally specialized
Description of a new species of Heligmonina Baylis, 1928 (Nematoda: Heligmonellidae) a parasite of Mastomys Natalensis (Rodentia: Muridae) from Swaziland and new data on the synlophe of Heligmonina Chabaudi (Desset, 1966)
A new species of heligmosomoid nematode belonging to the subfamily Nippostrongylinae Durette-Desset, 1970 is described: Heligmonina wakelini n. sp., a parasite from the small intestine of the commensal rodent Mastomys natalensis (Smith, 1834) from Swaziland. It differs from the most closely related species H. boomkeri Durette-Desset & Digiani, 2005 by the number of the cuticular ridges in the female synlophe (10 vs 12), the width of the left ala, larger than the body diameter in the male, and the inclination of the axis of orientation of the ridges in both sexes (53° vs 70°). New morphological data (head and synlophe) on Heligmonina chabaudi (Desset, 1964), also a parasite of Mastomys natalensis in the Republic of Congo, are provided in order to compare with the new species.Facultad de Ciencias Naturales y Muse
Description of a new species of Heligmonina Baylis, 1928 (Nematoda: Heligmonellidae) a parasite of Mastomys Natalensis (Rodentia: Muridae) from Swaziland and new data on the synlophe of Heligmonina Chabaudi (Desset, 1966)
A new species of heligmosomoid nematode belonging to the subfamily Nippostrongylinae Durette-Desset, 1970 is described: Heligmonina wakelini n. sp., a parasite from the small intestine of the commensal rodent Mastomys natalensis (Smith, 1834) from Swaziland. It differs from the most closely related species H. boomkeri Durette-Desset & Digiani, 2005 by the number of the cuticular ridges in the female synlophe (10 vs 12), the width of the left ala, larger than the body diameter in the male, and the inclination of the axis of orientation of the ridges in both sexes (53° vs 70°). New morphological data (head and synlophe) on Heligmonina chabaudi (Desset, 1964), also a parasite of Mastomys natalensis in the Republic of Congo, are provided in order to compare with the new species.Facultad de Ciencias Naturales y Muse
First Dark Matter Search Results from a 4-kg CF3I Bubble Chamber Operated in a Deep Underground Site
New data are reported from the operation of a 4.0 kg CF3I bubble chamber in the 6800 foot deep SNOLAB underground laboratory. The effectiveness of ultrasound analysis in discriminating alpha decay background events from single nuclear recoils has been confirmed, with a lower bound of >99.3% rejection of alpha decay events. Twenty single nuclear recoil event candidates and three multiple bubble events were observed during a total exposure of 553 kg-days distributed over three different bubble nucleation thresholds. The effective exposure for single bubble recoil-like events was 437.4 kg-days. A neutron background internal to the apparatus, of known origin, is estimated to account for five single nuclear recoil events and is consistent with the observed rate of multiple bubble events. The remaining excess of single bubble events exhibits characteristics indicating the presence of an additional background. These data provide new direct detection constraints on WIMP-proton spin-dependent scattering for WIMP masses >20 GeV/c2 and demonstrate significant sensitivity for spin-independent interactions
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