Improved Limits on Scattering of Weakly Interacting Massive Particles from Reanalysis of 2013 LUX Data.

We present constraints on weakly interacting massive particles (WIMP)-nucleus scattering from the 2013 data of the Large Underground Xenon dark matter experiment, including 1.4×10^{4} kg day of search exposure. This new analysis incorporates several advances: single-photon calibration at the scintillation wavelength, improved event-reconstruction algorithms, a revised background model including events originating on the detector walls in an enlarged fiducial volume, and new calibrations from decays of an injected tritium ß source and from kinematically constrained nuclear recoils down to 1.1 keV. Sensitivity, especially to low-mass WIMPs, is enhanced compared to our previous results which modeled the signal only above a 3 keV minimum energy. Under standard dark matter halo assumptions and in the mass range above 4 GeV c^{-2}, these new results give the most stringent direct limits on the spin-independent WIMP-nucleon cross section. The 90% C.L. upper limit has a minimum of 0.6 zb at 33 GeV c^{-2} WIMP mass.

Results on the Spin-Dependent Scattering of Weakly Interacting Massive Particles on Nucleons from the Run 3 Data of the LUX Experiment.

We present experimental constraints on the spin-dependent WIMP (weakly interacting massive particle)-nucleon elastic cross sections from LUX data acquired in 2013. LUX is a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility (Lead, South Dakota), which is designed to observe the recoil signature of galactic WIMPs scattering from xenon nuclei. A profile likelihood ratio analysis of 1.4×10^{4} kg day of fiducial exposure allows 90% C.L. upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of σ_{n}=9.4×10^{-41} cm^{2} (σ_{p}=2.9×10^{-39} cm^{2}) at 33 GeV/c^{2}. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.

First results from the LUX dark matter experiment at the Sanford underground research facility.

The Large Underground Xenon (LUX) experiment is a dual-phase xenon time-projection chamber operating at the Sanford Underground Research Facility (Lead, South Dakota). The LUX cryostat was filled for the first time in the underground laboratory in February 2013. We report results of the first WIMP search data set, taken during the period from April to August 2013, presenting the analysis of 85.3 live days of data with a fiducial volume of 118 kg. A profile-likelihood analysis technique shows our data to be consistent with the background-only hypothesis, allowing 90% confidence limits to be set on spin-independent WIMP-nucleon elastic scattering with a minimum upper limit on the cross section of 7.6 × 10(-46) cm(2) at a WIMP mass of 33 GeV/c(2). We find that the LUX data are in disagreement with low-mass WIMP signal interpretations of the results from several recent direct detection experiments.

An automated submicron beam profiler for characterization of high numerical aperture optics.

An automated, interferometrically referenced scanning knife-edge beam profiler with submicron resolution is demonstrated by directly measuring the focusing properties of three aspheric lenses with numerical aperture (NA) between 0.53 and 0.68, with spatial resolution of 0.02 microm. The results obtained for two of the three lenses tested were in agreement with paraxial Gaussian beam theory. It was also found that the highest NA aspheric lens, which was designed for 830 nm, was not diffraction limited at 633 nm. This process was automated using motorized translation stages and provides a direct method for testing the design specifications of high numerical aperture optics.

Impact of EMS education on emergency medicine ability and career choices of medical students.

OBJECTIVE: To determine whether a course in emergency medical services (EMS) impacts on the perceived ability of medical students to render care in emergencies such as choking and cardiac arrest, and affects their choice of emergency medicine as a career. METHODS: An eight-question pre- and postcourse survey was given to first- and second-year medical students. The elective course lasted a semester (four months) and dealt with prehospital emergency care, including ambulance rides and helicopter observation. Surveys were collected over a period of seven semesters. The eight-question survey assessed the student's experience, interest, and perceived competence. Precourse and postcourse results were compared using a chi-square with p<0.05 considered significant. RESULTS: Two hundred ten students enrolled in the EMS course. A total of 384 surveys were completed, 190 precourse and 194 postcourse surveys. Eighty-three students (44%) had a family member in the medical profession, five students (2.6%) had experience as an EMT or EMT-P, and 67 students (35%) had worked in any capacity in an ED. There was a statistically significant positive shift in the responses to both questions relating to self-perceived competency (p<0.01). Thirty-eight students (20%) precourse and 58 students (30%) postcourse were interested in emergency medicine as a career (p = 0.03). CONCLUSION: A course in EMS has significant impact on the perceived ability and career choice of medical students. Further study of an EMS curriculum design is needed to determine what information is critical to medical students' education and valuable in their career choice decisions.

The acting or interim leadership position: expectations, perceptions, realities.

The acting or interim leadership position has been neglected in terms of selection, role identification, and status. Individuals, programs, and organizations are paying a price for this inattention.

The role of the medical school dean's wife: report of a study.

The role of the medical school dean's wife was studied through a questionnaire distributed to wives of U.S. medical school deans. Responses of the wives are presented and discussed. Topics discussed include role orientation, perceived expectations, activities, resources, priorities, and satisfaction. A conceptual model is presented in the form of a three-part typology to describe the approaches used by wives as they play the role. The typology deals with the initiation, extent, and degree of role involvement in medical school activities by the wife of the dean.

Further observations on noise levels in infant incubators.

The purpose of this study was to conduct an acoustic analysis of incubator noise under two conditions: when the incubator was associated with different types of life-support equipment; and when impulse noise was created by striking the side of the incubator or by opening and closing the doors of the storage unit. It was found that the life-support equipment increased the overall noise levels of incubators by as much as 15 to 20 dB. Much of this increased energy was in the high frequency region. Impulse signals created by striking the side of the incubator ranged from 130 to 140 dB. A representative impulse for opening the incubator was 92.8 dB, whereas closing the door produced a peak amplitude of 114 dB.