17 research outputs found
A review of the deep-water volute genus <i>Calliotectum</i> (Gastropoda: Volutidae)
Calliotectum Dall, 1890, until now a monotypic deep-water volute genus from the Eastern Pacific, is shown to be a senior synonym of Teramachia Kuroda, 1931 from the Western Pacific. Pakaurangia Finlay, 1926 (originally Thiaridae; Miocene of New Zealand) and Butonius Martin. 1933 (originally Fusinidae; Neogene of Indonesia) are new synonyms. Calliotectum has a fossil record in the Neogene of the Pacific region (Okinawa, Indonesia, New Zealand and Ecuador), with a total of 5 species. All fossil records are from deep-water facies. Seven Recent species of Calliotectum are recognised, all from deep water in tropical latitudes. Three species occur in South-East Asia and the Eastern Indian Ocean, at 200-1660 m depth. Of these, C. tibiaeforme is treated as a polytypic species, with C. johnsoni and C. dupreyae considered to be geographical forms. Calliotectum piersonorum sp. nov. and C. egregium sp. nov. are described from the South-West Pacific at 450-1060 m depth. Single species occur each in the East Pacific and in the Caribbean
Singularities In Scalar-Tensor Cosmologies
In this article, we examine the possibility that there exist special
scalar-tensor theories of gravity with completely nonsingular FRW solutions.
Our investigation in fact shows that while most probes living in such a
Universe never see the singularity, gravity waves always do. This is because
they couple to both the metric and the scalar field, in a way which effectively
forces them to move along null geodesics of the Einstein conformal frame. Since
the metric of the Einstein conformal frame is always singular for
configurations where matter satisfies the energy conditions, the gravity wave
world lines are past inextendable beyond the Einstein frame singularity, and
hence the geometry is still incomplete, and thus singular. We conclude that the
singularity cannot be entirely removed, but only be made invisible to most, but
not all, probes in the theory.Comment: 23 pages, latex, no figure
Quantitative PCR tissue expression profiling of the human SGLT2 gene and related family members
SGLT2 (for “Sodium GLucose coTransporter” protein 2) is the major protein responsible for glucose reabsorption in the kidney and its inhibition has been the focus of drug discovery efforts to treat type 2 diabetes. In order to better clarify the human tissue distribution of expression of SGLT2 and related members of this cotransporter class, we performed TaqMan™ (Applied Biosystems, Foster City, CA, USA) quantitative polymerase chain reaction (PCR) analysis of SGLT2 and other sodium/glucose transporter genes on RNAs from 72 normal tissues from three different individuals. We consistently observe that SGLT2 is highly kidney specific while SGLT5 is highly kidney abundant; SGLT1, sodium-dependent amino acid transporter (SAAT1), and SGLT4 are highly abundant in small intestine and skeletal muscle; SGLT6 is expressed in the central nervous system; and sodium myoinositol cotransporter is ubiquitously expressed across all human tissues
Impact of CP phases on the search for sleptons tau and nu_tau
We study the decays of the tau-sleptons (stau_{1,2}) and tau-sneutrino
(snu_tau) in the Minimal Supersymmetric Standard Model (MSSM) with complex
parameters A_tau, mu and M_1 (U(1) gaugino mass). We show that the effect of
the CP phases of these parameters on the branching ratios of stau_{1,2} and
snu_tau decays can be quite strong in a large region of the MSSM parameter
space. This could have an important impact on the search for stau_{1,2} and
snu_tau and the determination of the MSSM parameters at future colliders.Comment: 15 pages, 5 figures, LaTeX2
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Applications of electrified dust and dust devil electrodynamics to Martian atmospheric electricity
Atmospheric transport and suspension of dust frequently brings electrification, which may be substantial. Electric fields of 10 kVm-1 to 100 kVm-1 have been observed at the surface beneath suspended dust in the terrestrial atmosphere, and some electrification has been observed to persist in dust at levels to 5 km, as well as in volcanic plumes. The interaction between individual particles which causes the electrification is incompletely understood, and multiple processes are thought to be acting. A variation in particle charge with particle size, and the effect of gravitational separation explains to, some extent, the charge structures observed in terrestrial dust storms. More extensive flow-based modelling demonstrates that bulk electric fields in excess of 10 kV m-1 can be obtained rapidly (in less than 10 s) from rotating dust systems (dust devils) and that terrestrial breakdown fields can be obtained. Modelled profiles of electrical conductivity in the Martian atmosphere suggest the possibility of dust electrification, and dust devils have been suggested as a mechanism of charge separation able to maintain current flow between one region of the atmosphere and another, through a global circuit. Fundamental new understanding of Martian atmospheric electricity will result from the ExoMars mission, which carries the DREAMS (Dust characterization, Risk Assessment, and Environment Analyser on the Martian Surface)-MicroARES (Atmospheric Radiation and Electricity Sensor) instrumentation to Mars in 2016 for the first in situ measurements