First Searches for Axions and Axionlike Particles with the LUX Experiment.

The first searches for axions and axionlike particles with the Large Underground Xenon experiment are presented. Under the assumption of an axioelectric interaction in xenon, the coupling constant between axions and electrons g_{Ae} is tested using data collected in 2013 with an exposure totaling 95 live days ×118 kg. A double-sided, profile likelihood ratio statistic test excludes g_{Ae} larger than 3.5×10^{-12} (90% C.L.) for solar axions. Assuming the Dine-Fischler-Srednicki-Zhitnitsky theoretical description, the upper limit in coupling corresponds to an upper limit on axion mass of 0.12 eV/c^{2}, while for the Kim-Shifman-Vainshtein-Zhakharov description masses above 36.6 eV/c^{2} are excluded. For galactic axionlike particles, values of g_{Ae} larger than 4.2×10^{-13} are excluded for particle masses in the range 1-16 keV/c^{2}. These are the most stringent constraints to date for these interactions.

Results from a Search for Dark Matter in the Complete LUX Exposure.

We report constraints on spin-independent weakly interacting massive particle (WIMP)-nucleon scattering using a 3.35×10^{4} kg day exposure of the Large Underground Xenon (LUX) experiment. A dual-phase xenon time projection chamber with 250 kg of active mass is operated at the Sanford Underground Research Facility under Lead, South Dakota (USA). With roughly fourfold improvement in sensitivity for high WIMP masses relative to our previous results, this search yields no evidence of WIMP nuclear recoils. At a WIMP mass of 50 GeV c^{-2}, WIMP-nucleon spin-independent cross sections above 2.2×10^{-46} cm^{2} are excluded at the 90% confidence level. When combined with the previously reported LUX exposure, this exclusion strengthens to 1.1×10^{-46} cm^{2} at 50 GeV c^{-2}.

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.

Perceived tutor benefits of teaching near peers: insights from two near peer teaching programmes in South East Scotland.

BACKGROUND AND AIMS: There is little evidence about the benefits to junior doctors of participating in teaching, or how to train doctors as teachers. We explore (through South East Scotland based teaching programmes): (a) How prepared do junior doctors feel to teach? (b) What junior doctors consider to be the main challenges of teaching? (c) What motivates the junior doctors to continue teaching, and what is the perceived impact of teaching on their professional development? METHODS AND RESULTS: 'Questionnaire 1', distributed at 'tutor training days', explored (i) attitudes towards teaching and (ii) tutors' preparedness to teach. 'Questionnaire 2', distributed after completion of a teaching programme, evaluated the tutor experience of teaching. RESULTS: Seventy-six per cent of tutors reported no previous teacher training; 10% were able to teach during allocated work hours. The strongest motivation for teaching was to help students with their learning and to develop teaching skills. Ninety one per cent of tutors felt more prepared to teach by the end of the programme. Tutors also improved their clinical skills from teaching. CONCLUSIONS: There is a body of junior doctors, who see teaching as an important part of their career, developing both teaching and clinical skills in the tutor. If teaching is expected of foundation doctors, rotas ought to be more flexible to facilitate both teaching and teacher training.

Variability in the attainment of functional milestones during the acute care admission after total joint replacement.

OBJECTIVE: To quantify patients' functional improvement in the immediate postoperative period after total hip arthroplasty (THA) or total knee arthroplasty (TKA). METHODS: A prospective observational study design was used to examine the number of physical therapy treatment sessions and postoperative days required to attain independence in 4 critical functional milestones, with independence defined as the ability to perform the activity without the assistance of another person. The 4 functional milestones selected were the ability to perform supine to sit transfers; sit to stand transfers; ambulation to 100'; and the ability to climb stairs. Consecutive patients undergoing elective THA or TKA for the first time at a community teaching hospital were entered into the study. RESULTS: The study group consisted of 81 patients undergoing elective THA or TKA (33 THA and 48 TKA). There was wide variability in the number of physical therapy sessions and postoperative days required to attain each of the 4 milestones and all 4 milestones. Climbing stairs was the most difficult task, followed by walking 100', performing sit to stand transfers, and performing supine to sit transfers. The achievement of the latter 2 milestones was similar. CONCLUSION: Our examination of patients' progress in attaining specific functional milestones is a unique approach to outcome assessment that emphasizes the physical therapy aspect of postsurgical rehabilitation. A wide variability in patients' functional progress during the acute care admission after elective THA or TKA was demonstrated. The reasons for this variability need to be explored since they may have important implications for planning rehabilitation related to THA, TKA or other orthopedic reconstructive procedures.

Human cytochrome b561: a revised hypothesis for conformation in membranes which reconciles sequence and functional information.

Cytochrome b561 is a major transmembrane protein of catecholamine and neuropeptide secretory vesicles. In this report, we describe the cloning and properties of a full-length cDNA encoding human neuroendocrine cytochrome b561 from a human caudate cDNA library and a human peripheral blood genomic library. The human cDNA contains two major transcription start sites and only one translation start site that codes for an apocytochrome b561, which is 22 amino acid residues smaller than the previously deduced amino acid sequence from bovine cDNA. This smaller version of cytochrome b561 may contain only five transmembrane segments rather than the previously proposed six segments. The new model is in agreement with our previous results on transmembrane topology of the gene product. Northern-blot analysis shows an expanded tissue distribution of cytochrome mRNA expression where previous immunological assays were negative. These results support the hypothesis that cytochrome b561 is a marker for peptidergic and adrenergic tissues.

Brief communication: possible third molar impactions in the hominid fossil record.

Impacted third molars affect 15%-20% of modern Americans and Western Europeans. In contrast, third molar impactions have not been reported in the early hominid fossil record. It is uncertain whether the lack of reports reflects an absence of impactions or a failure to recognize them. This communication is intended to raise awareness of the possibility of impactions by describing the appearance of impacted teeth and by noting two possible instances of impaction in early hominids. Specifically, the mandibular third molars of the Sterkfontein specimen, STS52b (Australopithecus africanus), and the left maxillary third molar of the Lake Turkana specimen, KNM-WT 17400 (Australopithecus boisei), are positioned in a manner which suggests that they would not have erupted normally. Both specimens also exhibit strong crowding of the anterior dentition, providing further support for the view that these individuals lacked sufficient space for normal eruption of the third molars. Other published reports of dental crowding in the hominid fossil record are noted, and it is suggested that more attention be paid to dental impaction and dental crowding in hominid evolution.

Expression of dopamine beta-hydroxylase in Drosophila Schneider 2 cells. Evidence for a mechanism of membrane binding other than uncleaved signal peptide.

To characterize the mechanism of membrane attachment of dopamine beta-hydroxylase, an expression system producing the processed form of this enzyme has been developed. We have replaced the endogenous signal peptide of bovine dopamine beta-hydroxylase with a heterologous signal peptide which is efficiently recognized and cleaved in Drosophila Schneider 2 cells. A cDNA encoding this chimeric recombinant bovine enzyme has been stably transfected into Schneider 2 cells. The inducible expression of active dopamine beta-hydroxylase in these cells has been verified by Western blotting and enzyme activity assays. N-terminal sequence analysis of purified recombinant enzyme demonstrates complete removal of the signal peptide. Subcellular analysis shows that the recombinant enzyme exists as both a soluble and a membrane-bound form in these cells. These data demonstrate that the endogenous signal peptide is not required for the formation of the membranous dopamine beta-hydroxylase and further that the enzyme can be bound to membranes via a mechanism other than uncleaved signal sequence.

Human dental reduction: natural selection or the probable mutation effect.

Dental reduction has been sufficiently widespread among human populations to render the phenomenon of reduced tooth size worthy of scientific explanation. One of the most controversial models invoked to explain structural reduction in organisms is referred to as the "probable mutation effect" (PME). According to this model, structures no longer functional owing to ecological or cultural changes will experience a relaxation of selection pressure, permitting an accumulation of mutations in the population that inevitably will result in the reduction in size or the loss of the concerned structure. Although the PME continues to be offered as a viable explanation of human dental reduction, it is based upon several premises that modern dental clinical experience fails to support. Known enzyme defects resulting from mutations, factors predisposing to dental infections, and the deleterious effects of teeth that are too large or too small reveal that the PME does not logically account for the reduction of tooth size. Given such information, this paper proposes models of dental reduction based upon natural selection, which, unlike the PME, are testable in both modern and archaeological populations. The integration of clinical and skeletal data permits a more thorough understanding of dental reduction in the hominid fossil record.

Cooperative care. The time has come.

What happens when patients decide when to take their medications, when to eat, what to wear, and what family member will stay with them? These authors state the result of these patient self-care activities are reduced cost, and more satisfied patients and staff.

Rheumatoid arthritis of the shoulder.

The shoulder frequently is affected by rheumatoid arthritis (RA), often resulting in musculoskeletal dysfunction. The primary purpose of this article is to provide the clinician with an in-depth look at the pathological factors and treatment of RA as it affects the shoulder. The review includes sections on pathological factors, radiology, morbidity, clinical manifestations, and both conservative and surgical management. The secondary purpose of this article is to acquaint the clinician with some of the other rheumatic diseases in which shoulder dysfunction may occur. I hope that the presentation of management principles will stimulate discussion and interest regarding the scientific rationale for the treatment of musculoskeletal manifestations of RA.