Laser cooling of a trapped two-component Fermi gas

The collective Raman cooling of a trapped two-component Fermi gas is analyzed. We develop the quantum master equation that describes the collisions and the laser cooling, in the festina lente regime, where the heating due to photon reabsorption can be neglected. The numerical results based on Monte Carlo simulations show, that three-dimensional temperatures of the order of 0.008 T_F can be achieved. We analyze the heating related to the background losses, and conclude that our laser-cooling scheme can maintain the temperature of the gas without significant additional losses. Finally we derive an analytic expression for the temperature of a trapped Fermi gas heated by background collisions, that agrees very well with the data obtained from the numerical simulation.Comment: 5 pages, 3 figure

Spin battery operated by ferromagnetic resonance

Precessing ferromagnets are predicted to inject a spin current into adjacent conductors via Ohmic contacts, irrespective of a conductance mismatch with, for example, doped semiconductors. This opens the way to create a pure spin source spin battery by the ferromagnetic resonance. We estimate the spin current and spin bias for different material combinations.Comment: The estimate for the magnitude of the spin bias is improved. We find that it is feasible to get a measurable signal of the order of the microwave frequency already for moderate rf intensitie

Traumatic brain and spinal cord fatalities among high school and college football players — United States, 2005–2014

Summary What is already known about this topic? Fatalities resulting from catastrophic brain and spinal cord injuries occur infrequently among high school and college football players. What is added by this report? During 2005–2014, a total of 28 traumatic brain and spinal cord injury deaths in high school and college football were identified (2.8 deaths per year). The most common playing positions of those fatally injured were running back and linebacker. Approximately 18% of identified high school brain injury deaths were preceded by an earlier concussion, which might have led to second impact syndrome. What are the implications for public health practice? Implementing enhanced safety measures to prevent fatalities from catastrophic brain and spinal cord injuries among high school and college football players has the potential to reduce the number of these fatalities. Continued surveillance is important to monitor the circumstances of these deaths and develop risk scenarios to improve prevention measures

Materiality in information environments: Objects, spaces, and bodies in three outpatient hemodialysis facilities

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152032/1/asi24277.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152032/2/asi24277_am.pd

Dependence of Curie Temperature on the Thickness of Epitaxial (Ga,Mn)As Film

We present the magnetotransport properties of very thin (5 to 15 nm) single (Ga,Mn)As layers grown by low temperature molecular beam epitaxy. A lower (Ga,Mn)As thickness limit of 5 nm for the ferromagnetic phase and the dependence of the Curie temperature on (Ga,Mn)As thickness are determined from electrical transport measurements. The Curie temperature is determined to be 97 K for the thinnest ferromagnetic sample and is found to decrease for increasing layer thickness. A carrier density of ~7.1$\times10^{20}$ cm$^{-3}$ for the 5 nm thick (Ga,Mn)As layer is determined from Hall measurements. Differences between magnetotransport properties of thick and thin (Ga,Mn)As layers are observed and discussed.Comment: 6 pages, 4 figure

Photoproduction of mesons off nuclei

Recent results for the photoproduction of mesons off nuclei are reviewed. These experiments have been performed for two major lines of research related to the properties of the strong interaction. The investigation of nucleon resonances requires light nuclei as targets for the extraction of the isospin composition of the electromagnetic excitations. This is done with quasi-free meson photoproduction off the bound neutron and supplemented with the measurement of coherent photoproduction reactions, serving as spin and/or isospin filters. Furthermore, photoproduction from light and heavy nuclei is a very efficient tool for the study of the interactions of mesons with nuclear matter and the in-medium properties of hadrons. Experiments are currently rapidly developing due to the combination of high quality tagged (and polarized) photon beams with state-of-the-art 4pi detectors and polarized targets

Study of the B^0 Semileptonic Decay Spectrum at the Upsilon(4S) Resonance

We have made a first measurement of the lepton momentum spectrum in a sample of events enriched in neutral B's through a partial reconstruction of B0 --> D*- l+ nu. This spectrum, measured with 2.38 fb**-1 of data collected at the Upsilon(4S) resonance by the CLEO II detector, is compared directly to the inclusive lepton spectrum from all Upsilon(4S) events in the same data set. These two spectra are consistent with having the same shape above 1.5 GeV/c. From the two spectra and two other CLEO measurements, we obtain the B0 and B+ semileptonic branching fractions, b0 and b+, their ratio, and the production ratio f+-/f00 of B+ and B0 pairs at the Upsilon(4S). We report b+/b0=0.950 (+0.117-0.080) +- 0.091, b0 = (10.78 +- 0.60 +- 0.69)%, and b+ = (10.25 +- 0.57 +- 0.65)%. b+/b0 is equivalent to the ratio of charged to neutral B lifetimes, tau+/tau0.Comment: 14 page, postscript file also available at http://w4.lns.cornell.edu/public/CLN

Fitting the integrated Spectral Energy Distributions of Galaxies

Fitting the spectral energy distributions (SEDs) of galaxies is an almost universally used technique that has matured significantly in the last decade. Model predictions and fitting procedures have improved significantly over this time, attempting to keep up with the vastly increased volume and quality of available data. We review here the field of SED fitting, describing the modelling of ultraviolet to infrared galaxy SEDs, the creation of multiwavelength data sets, and the methods used to fit model SEDs to observed galaxy data sets. We touch upon the achievements and challenges in the major ingredients of SED fitting, with a special emphasis on describing the interplay between the quality of the available data, the quality of the available models, and the best fitting technique to use in order to obtain a realistic measurement as well as realistic uncertainties. We conclude that SED fitting can be used effectively to derive a range of physical properties of galaxies, such as redshift, stellar masses, star formation rates, dust masses, and metallicities, with care taken not to over-interpret the available data. Yet there still exist many issues such as estimating the age of the oldest stars in a galaxy, finer details ofdust properties and dust-star geometry, and the influences of poorly understood, luminous stellar types and phases. The challenge for the coming years will be to improve both the models and the observational data sets to resolve these uncertainties. The present review will be made available on an interactive, moderated web page (sedfitting.org), where the community can access and change the text. The intention is to expand the text and keep it up to date over the coming years.Comment: 54 pages, 26 figures, Accepted for publication in Astrophysics & Space Scienc

An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types

Observation of hard scattering in photoproduction events with a large rapidity gap at HERA

Events with a large rapidity gap and total transverse energy greater than 5 GeV have been observed in quasi-real photoproduction at HERA with the ZEUS detector. The distribution of these events as a function of the $\gamma p$ centre of mass energy is consistent with diffractive scattering. For total transverse energies above 12 GeV, the hadronic final states show predominantly a two-jet structure with each jet having a transverse energy greater than 4 GeV. For the two-jet events, little energy flow is found outside the jets. This observation is consistent with the hard scattering of a quasi-real photon with a colourless object in the proton.Comment: 19 pages, latex, 4 figures appended as uuencoded fil