Magnetic field effects on the density of states of orthorhombic superconductors

The quasiparticle density of states in a two-dimensional d-wave superconductor depends on the orientation of the in-plane external magnetic field H. This is because. in the region of the gap nodes, the Doppler shift due to the circulating supercurrents around a vortex depend on the direction of H. For a tetragonal system the induced pattern is four-fold symmetric and, at zero energy, the density of states exhibits minima along the node directions. But YBa_2C_3O_{6.95} is orthorhombic because of the chains and the pattern becomes two-fold symmetric with the position of the minima occuring when H is oriented along the Fermi velocity at a node on the Fermi surface. The effect of impurity scattering in the Born and unitary limit is discussed.Comment: 24 pages, 11 Figure

A First Search for coincident Gravitational Waves and High Energy Neutrinos using LIGO, Virgo and ANTARES data from 2007

We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.Comment: 19 pages, 8 figures, science summary page at http://www.ligo.org/science/Publication-S5LV_ANTARES/index.php. Public access area to figures, tables at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p120000

A double blind, placebo controlled study of the effects of low dose testosterone undecanoate on the growth of small for age, prepubertal boys.

OBJECTIVE--To assess whether very low doses of testosterone can accelerate growth without an undue advance in bone age in prepubertal boys with constitutional delay of growth. SUBJECTS--23 prepubertal boys aged 11-14 years with height at or below the third centile for chronological age. DESIGN--Randomised, double blind trial comparing oral testosterone undecanoate 20 mg once daily versus placebo for six months. The 18 months' observation period of each subject comprised a six month pretreatment period, followed by a six month treatment (testosterone undecanoate or placebo) period, and a six month period after termination of treatment. OUTCOME MEASURES--At intervals of six months standing and sitting height were measured. Bone age, pubertal stage, weight, and lean body mass were also determined. Growth hormone, luteinising hormone, and follicle stimulating hormone secretion and testosterone concentration were measured before, after, and six months after treatment. RESULTS--Boys taking testosterone undecanoate (n = 11) showed a significantly greater height velocity (mean (SEM) 5.84 (0.53) cm/year) and sitting height velocity (3.54 (0.57) cm/year) during treatment than the placebo treated boys (n = 12, height velocity = 3.38 (0.22) cm/year, sitting height velocity = 1.58 (0.19) cm/year. There were no significant differences between the groups regarding changes in growth hormone, gonadotrophins, testosterone, or dihydrotestosterone concentrations. Bone age was not advanced significantly more rapidly in either group. CONCLUSIONS--There is accelerated gain in height during six months of treatment with low dose testosterone undecanoate, without a significantly greater rise in bone age compared with controls. Testosterone undecanoate is a safe, well tolerated, and effective treatment in the management of constitutional delay of growth