23,047 research outputs found
Forbidden Ca 2 in the sun unmasked by way of Venus
Eleven high-dispersion spectra of Venus, taken with blue Doppler shifts have permitted the unmasking of the 7323.88A forbidden line of Ca II from terrestrial absorption. An equivalent width is obtained of 7.4 + or - 0.4mA for this line in integrated sunlight. Our value of W sub lambda is smaller than previous values and much more accurate. The HSRA solar model gives a solar calcium abundance of A sub Ca = 6.21
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Case report: targeted whole exome sequencing enables the first prenatal diagnosis of the lethal skeletal dysplasia Osteocraniostenosis.
BACKGROUND: Osteocraniostenosis (OCS) is a rare genetic disorder characterised by premature closure of cranial sutures, gracile bones and perinatal lethality. Previously, diagnosis has only been possible postnatally on clinical and radiological features. This study describes the first prenatal diagnosis of OCS. CASE PRESENTATION: In this case prenatal ultrasound images were suggestive of a serious but non-lethal skeletal dysplasia. Due to the uncertain prognosis the parents were offered Whole Exome Sequencing (WES), which identified a specific gene mutation in the FAMIIIa gene. This mutation had previously been detected in two cases and was lethal in both perinatally. This established the diagnosis, a clear prognosis and allowed informed parental choice regarding ongoing pregnancy management. CONCLUSIONS: This case report supports the use of targeted WES prenatally to confirm the underlying cause and prognosis of sonographically suspected abnormalities
Studies of the superconducting properties of Sn1-xInxTe (x=0.38 to 0.45) using muon-spin spectroscopy
The superconducting properties of Sn1-xInxTe (x = 0.38 to 0.45) have been
studied using magnetization and muon-spin rotation or relaxation (muSR)
measurements. These measurements show that the superconducting critical
temperature Tc of Sn1-xInxTe increases with increasing x, reaching a maximum at
around 4.8 K for x = 0.45. Zero-field muSR results indicate that time-reversal
symmetry is preserved in this material. Transverse-field muon-spin rotation has
been used to study the temperature dependence of the magnetic penetration depth
lambda(T) in the mixed state. For all the compositions studied, lambda(T) can
be well described using a single-gap s-wave BCS model. The magnetic penetration
depth at zero temperature lambda(0) ranges from 500 to 580 nm. Both the
superconducting gap Delta(0) at 0 K and the gap ratio Delta(0)/kBTc indicate
that Sn1-xInxTe (x = 0.38 to 0.45) should be considered as a superconductor
with intermediate to strong coupling.Comment: 7 pages, 6 figures, 3 table
The B Neutrino Spectrum
Knowledge of the energy spectrum of B neutrinos is an important
ingredient for interpreting experiments that detect energetic neutrinos from
the Sun. The neutrino spectrum deviates from the allowed approximation because
of the broad alpha-unstable Be final state and recoil order corrections to
the beta decay. We have measured the total energy of the alpha particles
emitted following the beta decay of B. The measured spectrum is
inconsistent with some previous measurements, in particular with a recent
experiment of comparable precision. The beta decay strength function for the
transition from B to the accessible excitation energies in Be is fit to
the alpha energy spectrum using the R-matrix approach. Both the positron and
neutrino energy spectra, corrected for recoil order effects, are constructed
from the strength function. The positron spectrum is in good agreement with a
previous direct measurement. The neutrino spectrum disagrees with previous
experiments, particularly for neutrino energies above 12 MeV.Comment: 15 pages, 13 figures, 4 tables, submitted to Phys. Rev. C, typos
correcte
Probing the superconducting ground state of the rare-earth ternary boride superconductors RuB ( = Lu,Y) using muon-spin rotation and relaxation
The superconductivity in the rare-earth transition metal ternary borides
RuB (where = Lu and Y) has been investigated using muon-spin
rotation and relaxation. Measurements made in zero-field suggest that
time-reversal symmetry is preserved upon entering the superconducting state in
both materials; a small difference in depolarization is observed above and
below the superconducting transition in both compounds, however this has been
attributed to quasistatic magnetic fluctuations. Transverse-field measurements
of the flux-line lattice indicate that the superconductivity in both materials
is fully gapped, with a conventional s-wave pairing symmetry and BCS-like
magnitudes for the zero-temperature gap energies. The electronic properties of
the charge carriers in the superconducting state have been calculated, with
effective masses and in the Lu
and Y compounds, respectively, with superconducting carrier densities
() m and ()
m. The materials have been classified according to the
Uemura scheme for superconductivity, with values for
of and , implying that
the superconductivity may not be entirely conventional in nature.Comment: 8 pages, 8 figure
Animal-Assisted Interventions in Health Care Settings: A Best Practices Manual for Establishing New Programs: Volunteer Manual Template
This document accompanies Animal-Assisted Interventions in Health Care Settings: A Best Practices Manual for Establishing New Programs (Purdue Press, 2019) and serves as a template for readers to personalize for their facility. The generic terms âABC Health Care Facilityâ and âAAI Programâ are intended to be replaced by the names of the reader\u27s facility and AAI program.
The book can be purchased from Purdue University Press
Optomechanical cooling of levitated spheres with doubly-resonant fields
Optomechanical cooling of levitated dielectric particles represents a
promising new approach in the quest to cool small mechanical resonators towards
their quantum ground state. We investigate two-mode cooling of levitated
nanospheres in a self-trapping regime. We identify a rich structure of split
sidebands (by a mechanism unrelated to usual strong-coupling effects) and
strong cooling even when one mode is blue detuned. We show the best regimes
occur when both optical fields cooperatively cool and trap the nanosphere,
where cooling rates are over an order of magnitude faster compared to
corresponding single-sideband cooling rates.Comment: 8 Pages, 7 figure
Time-reversal symmetry breaking in noncentrosymmetric superconductor Re6Hf:further evidence for unconventional behaviour in the alpha-Mn family of materials
The discovery of new families of unconventional superconductors is important
both experimentally and theoretically, especially if it challenges current
models and thinking. By using muon spin relaxation in zero-field, time-reversal
symmetry breaking has been observed in Re6Hf. Moreover, the temperature
dependence of the superfluid density exhibits s-wave superconductivity with an
enhanced electron-phonon coupling. This, coupled with the results from
isostructural Re6Zr, shows that the Re6X family are indeed a new and important
group of unconventional superconductors.Comment: 5 pages, 2 figures Accepted Physical Review B, Rapid Communicatio
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