84 research outputs found
Mitochondrial diversity analysis of Glossina palpalis gambiensis from Mali and Senegal
West African riverine tsetse populations of Glossina palpalis gambiensis Vanderplank (Diptera: Glossinidae) were investigated for gene flow, inferred from mitochondrial diversity in samples of 69 flies from Senegal and 303 flies from three river drainages in Mali. Four polymorphic mitochondrial loci were scored. Mean haplotype diversities were 0.30 in Mali and 0.18 over both Mali and Senegal. These diversities estimate the probabilities that two randomly chosen tsetse have different haplotypes. Substantial rates of gene flow were detected among flies sampled along tributaries belonging to the river basins of the Senegal, Niger, and Bani in Mali. There was virtually no gene flow between tsetse in Senegal and Mali. No seasonal effects on gene flow were detected. The implications of these preliminary findings for the implementation of area-wide integrated pest management (AW-IPM) programmes against riverine tsetse in West Africa are discussed
Axial Involvement in Psoriatic Arthritis cohort (AXIS): the protocol of a joint project of the Assessment of SpondyloArthritis international Society (ASAS) and the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA)
Background: Involvement of the axial skeleton (sacroiliac joints and spine) is a relatively frequent manifestation associated with psoriatic skin disease, mostly along with involvement of peripheral musculoskeletal structures (peripheral arthritis, enthesitis, dactylitis), which are referred to as psoriatic arthritis (PsA). Data suggest that up to 30% of patients with psoriasis have PsA. Depending on the definition used, the prevalence of axial involvement varies from 25% to 70% of patients with PsA. However, there are currently no widely accepted criteria for axial involvement in PsA.Objective: The overarching aim of the Axial Involvement in Psoriatic Arthritis (AXIS) study is to systematically evaluate clinical and imaging manifestations indicative of axial involvement in patients with PsA and to develop classification criteria and a unified nomenclature for axial involvement in PsA that would allow defining a homogeneous subgroup of patients for research.Design: Prospective, multicenter, multinational, cross-sectional study.Methods and analyses: In this multicenter, multinational, cross-sectional study, eligible patients [adult patients diagnosed with PsA and fulfilling Classification Criteria for Psoriatic Arthritis (CASPAR) with musculoskeletal symptom duration of <= 10 years not treated with biological or targeted synthetic disease-modifying anti-rheumatic drugs] will be recruited prospectively. They will undergo study-related clinical and imaging examinations. Imaging will include radiography and magnetic resonance imaging examinations of sacroiliac joints and spine. Local investigators will evaluate for the presence of axial involvement based on clinical and imaging information which will represent the primary outcome of the study. In addition, imaging will undergo evaluation by central review. Finally, the central clinical committee will determine the presence of axial involvement based on all available information.Ethics: The study will be performed according to the ethical principles of the Declaration of Helsinki and International Council for Harmonisation Good Clinical Practice guidelines. The study protocol will be approved by the individual Independent Ethics Committee / Institutional Review Board of participating centers. Written informed consent will be obtained from all included patients.Pathophysiology and treatment of rheumatic disease
EuFeAs under high pressure: an antiferromagnetic bulk superconductor
We report the ac magnetic susceptibility and resistivity
measurements of EuFeAs under high pressure . By observing nearly
100% superconducting shielding and zero resistivity at = 28 kbar, we
establish that -induced superconductivity occurs at ~30 K in
EuFeAs. shows an anomalous nearly linear temperature dependence
from room temperature down to at the same . indicates that
an antiferromagnetic order of Eu moments with ~20 K persists
in the superconducting phase. The temperature dependence of the upper critical
field is also determined.Comment: To appear in J. Phys. Soc. Jpn., Vol. 78 No.
Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at s=8 TeV
Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7 fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale
FIRST SEARCHES FOR OPTICAL COUNTERPARTS TO GRAVITATIONAL-WAVE CANDIDATE EVENTS
During the LIGO and Virgo joint science runs in 2009-2010, gravitational wave (GW) data from three interferometer detectors were analyzed within minutes to select GW candidate events and infer their apparent sky positions. Target coordinates were transmitted to several telescopes for follow-up observations aimed at the detection of an associated optical transient. Images were obtained for eight such GW candidates. We present the methods used to analyze the image data as well as the transient search results. No optical transient was identified with a convincing association with any of these candidates, and none of the GW triggers showed strong evidence for being astrophysical in nature. We compare the sensitivities of these observations to several model light curves from possible sources of interest, and discuss prospects for future joint GW-optical observations of this type
Searches for electroweak neutralino and chargino production in channels with Higgs, Z, and W bosons in pp collisions at 8 TeV
Searches for supersymmetry (SUSY) are presented based on the electroweak pair production of neutralinos and charginos, leading to decay channels with Higgs, Z, and W bosons and undetected lightest SUSY particles (LSPs). The data sample corresponds to an integrated luminosity of about 19.5 fb(-1) of proton-proton collisions at a center-of-mass energy of 8 TeV collected in 2012 with the CMS detector at the LHC. The main emphasis is neutralino pair production in which each neutralino decays either to a Higgs boson (h) and an LSP or to a Z boson and an LSP, leading to hh, hZ, and ZZ states with missing transverse energy (E-T(miss)). A second aspect is chargino-neutralino pair production, leading to hW states with E-T(miss). The decays of a Higgs boson to a bottom-quark pair, to a photon pair, and to final states with leptons are considered in conjunction with hadronic and leptonic decay modes of the Z and W bosons. No evidence is found for supersymmetric particles, and 95% confidence level upper limits are evaluated for the respective pair production cross sections and for neutralino and chargino mass values
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Compositional gradients in natural silicic liquids
Electron microprobe analyses of natural rhyolite glass reveal compositional gradients 10 to 15 ..mu..m wide adjacent to microphenocrysts of plagioclase, alkali feldspar, and magnetite. The presence of such gradients has previously been interpreted as indicative of disequilibrium between liquid and solid. If crystals and liquid are not in compositional equilibrium, temperatures determined from the compositions of coexisting mineral phases might be erroneous. Gradients may be attributed, however, to diffusion controlled crystallization. Because convection of magma is indicated based on a comparison of characteristic transport distances and thickness of compositional boundary layers the model of Tiller et al. (1953) is deemed inappropriate. The microprobe data are consistent with the model of Burton, Prim, and Slichter (1953) in which the liquid is stirred by convection and the crystals are surrounded by a diffusive-advective boundary layer. Computed apparent and equilibrium distribution coefficients for natural rhyolites, combined with published diffusion coefficients for K, yield linear growth rates for feldspars on the order of 7 x 10/sup -7/ cm sec/sup -1/, similar to experimentally determined equilibrium growth rates. The analytical data are consistent with a model of diffusion controlled crystallization in natural silicic liquids, and the utilization of coexisting phases for thermometry remains reasonable in the presence of narrow compositional gradients
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Oxygen-isotope geochemistry of quaternary rhyolite from the Mineral Mountains, Utah, USA
Oxygen isotope analyses were made of phenocryst and glass separates from four Quaternary rhyolite flows and domes in the Mineral Mountains, southwest Utah. With the exception of biotite in all samples and alkali feldspar in the rhyolite domes, all minerals appear to be in close oxygen isotope exchange equilibrium. The geothermometry equations proposed by Bottinga and Javoy (1973) and Javoy (1977) for quartz, alkali feldspar and magnetite produce the best agreement with temperature results fom two-feldspar and iron-titanium oxide geothermometry for these rhyolites. If the rhyolites were generated by partial melting in the crust, their whole-rock (glass) delta/sup 18/O values (6.3 to 6.9 permil) are consistent with generation from I-type (Chappell and White, 1974, O'Neil and Chappell, 1977; O'Neil et. al., 1977) sources
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Petrology, geochronology, and chemical evolution of the Twin Peaks Rhyolite Domes, Utah
Two distinct sequences of silicic volcanism at the Twin Peaks volcanic field, Millard County, Utah, spanned periods from 2.74 +- .10 to 2.54 +- .09 m.y. and 2.43 +- .08 to 2.35 +- .08 m.y., and produced a total exposed volume of 4 km/sup 3/ of rhyolites and volcanoclastics. Wet chemical, x-ray fluorescence, microprobe, atomic absorption, and neutron activation methods have been employed to obtain a wide range of chemical data on whole rock and mineral separate samples. Calculated distribution coefficients are comparable to previously published values for high silica rocks. Each sequence is characterized by a systematic trend from < 72% to > 76% SiO/sub 2/. Accompanying this increase in SiO/sub 2/ over time are increases in Rb, Y, Sb, Cs, U, Th, HREE and decreases in Mg, Co, Fe, Sr, Ba, and LREE. Decreases in temperature and fO/sub 2/ and an increase in fH/sub 2/O are also indicated. These trends are very similar to gradients observed in ash flow tuffs erupted instantaneously from compositionally zoned magma chambers. Chemical evolution at Twin Peaks was dominated by the same mechanism of liquid state differentiation which produce the compositional zonation in larger silicic magma chambers
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Part I - Geology and Geochemistry of the Roosevelt Hot Springs - A Summary. Part II - Geophysics of the Roosevelt Hot Springs Thermal Area, Utah. Part III - Roosevelt Hot Springs Area Field Trip
The Roosevelt Hot Springs Thermal Area is a newly discovered geothermal power prospect. Seven production wells have been drilled with a maximum flow capability averaging 4.5 x 10{sup 5} kg of combined vapor and liquid per hour at a bottom hole temperature of 260 C. The thermal area is located on the western-margin of the Mineral Mountains, which consist dominantly of a Tertiary granitic pluton 32 km long by 8 km wide. Rhyolitic tuffs, flows, and domes cover about 25 km{sup 2} of the crest and west side of the Mineral Mountains within 5 km of the thermal area. The rhyolitic volcanism occurred between 0.8 and 0.5 m.y. ago and constitutes a major Pleistocene thermal event believed to be significant to the evaluation of the Roosevelt Thermal area. Thermal waters of the dry spring, a seep, and the deep reservoir are dilute (ionic strength 0.1 to 0.2) sodium chloride brines. Spring deposits consist of siliceous sinter and manor sulfur. Alluvium is cemented by sinter and altered in varying degrees by hot, acid-sulfate water to opal and alunite at the surface, grading successively to alunite-kaolinite, alunite-kaolinite-montmorillonite, and muscovite-pyrite within 60 m of the surface. Observed alteration and water chemistry are consistent with a model in which hot aqueous solutions containing H{sub 2}S and sulfate convectively rise along major fractures. Hydrogen sulfide oxides to sulfate near the surface decreasing the pH and causes alunite to form. Opal precipitates as the solutions cool. Kaolinite, muscovite, and K-feldspar are formed in sequence, as the thermal water percolated downward and hydrogen ion and sulfate are consumed
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