Dynamic polarization of graphene by moving external charges: random phase approximation

We evaluate the stopping and image forces on a charged particle moving parallel to a doped sheet of graphene by using the dielectric response formalism for graphene's $\pi$-electron bands in the random phase approximation (RPA). The forces are presented as functions of the particle speed and the particle distance for a broad range of charge-carrier densities in graphene. A detailed comparison with the results from a kinetic equation model reveal the importance of inter-band single-particle excitations in the RPA model for high particle speeds. We also consider the effects of a finite gap between graphene and a supporting substrate, as well as the effects of a finite damping rate that is included through the use of Mermin's procedure. The damping rate is estimated from a tentative comparison of the Mermin loss function with a HREELS experiment. In the limit of low particle speeds, several analytical results are obtained for the friction coefficient that show an intricate relationship between the charge-carrier density, the damping rate, and the particle distance, which may be relevant to surface processes and electrochemistry involving graphene.Comment: 14 pages, 10 figures, accepted for publication in Phys. Rev.

New Experimental Limits on Macroscopic Forces Below 100 Microns

Results of an experimental search for new macroscopic forces with Yukawa range between 5 and 500 microns are presented. The experiment uses 1 kHz mechanical oscillators as test masses with a stiff conducting shield between them to suppress backgrounds. No signal is observed above the instrumental thermal noise after 22 hours of integration time. These results provide the strongest limits to date between 10 and 100 microns, improve on previous limits by as much as three orders of magnitude, and rule out half of the remaining parameter space for predictions of string-inspired models with low-energy supersymmetry breaking. New forces of four times gravitational strength or greater are excluded at the 95% confidence level for interaction ranges between 200 and 500 microns.Comment: 25 Pages, 7 Figures: Minor Correction

Trends of increase in western medical services in traditional medicine hospitals in china

Background: Compare changes in types of hospital service revenues between traditional Chinese medicine (TCM) hospitals and Western-medicine based general hospitals. Methods: 97 TCM hospitals and 103 general hospitals were surveyed in years of 2000 and 2004. Six types of medical service revenue between the two types of hospitals were compared overtime. The national statistics from 1999 to 2008 were also used as complementary evidence. Results: For TCM hospitals, the percentage of service revenue from Western medicine increased from 44.3% to 47.4% while the percentage of service revenue from TCM declined from 26.4% to 18.8% from 1999 to 2004. Percentages of revenue from laboratory tests and surgical procedures for both types of hospitals increased and the discrepancy between the two types of hospitals was narrowed from 1999 to 2004. For TCM hospitals, revenues from laboratory tests increased from 3.64% to 5.06% and revenues from surgical procedures increased from 3.44% to 7.02%. General hospitals\u27 TCM drug revenue in outpatient care declined insignificantly from 5.26% to 3.87%, while the decline for the TCM hospitals was significant from 19.73% to 13.77%. The national statistics from 1999 to 2008 showed similar trends that the percentage of revenue from Western medicine for TCM hospitals increased from 59.6% in 1999 to 62.2% in 2003 and 66.1% in 2008 while the percentage of revenue from TCM for TCM hospitals decreased from 18.0% in 1999, 15.4% in 2003, and 13.7% in 2008. Conclusion: Western medicine has become a vital revenue source for TCM hospitals in the current Chinese health care environment where government subsidies to health care facilities have significantly declined. Policies need to encourage TCM hospitals to identify their own special and effective services, improve public perception, increase demand, strengthen financial sources, and ultimately make contributions to preserving one of the national treasures

Association between antipsychotics and weight gain among psychiatric outpatients in Pakistan: a retrospective cohort study

<p>Abstract</p> <p>Background</p> <p>It has been known for a long time that use of antipsychotics, particularly atypical antipsychotics, is associated with weight gain and increase in risk of metabolic disturbances. In this study we have tried to find out if use of antipsychotics is associated with increase in weight and body mass index (BMI) in the Pakistani population.</p> <p>Methods</p> <p>We performed a case note review of all patients who had been prescribed antipsychotic medication at the psychiatry outpatient clinic of a tertiary care university hospital in Pakistan over a 4-year period.</p> <p>Results</p> <p>A total of 50% of patients had a BMI in the overweight or higher range at baseline. Patients showed a mean weight gain of 1.88 kg from baseline in 3 months and 3.29 kg in 6 months. Both of these values were statistically significant. The increase in mean BMI from baseline was 0.74 and 1.3 in 3 months and 6 months, respectively. In patients for whom we had at least one further weight measurement after baseline, 48% (39/81) showed a clinically significant weight gain.</p> <p>Conclusion</p> <p>Pakistani patients are just as likely to put on weight during antipsychotic treatment as patients from other countries. Considering that this population already has a much higher prevalence of diabetes mellitus compared to the Western countries, the consequences of increased weight may be even more serious in terms of increased morbidity and mortality.</p

Higgs-mediated FCNCs: Natural Flavour Conservation vs. Minimal Flavour Violation

We compare the effectiveness of two hypotheses, Natural Flavour Conservation (NFC) and Minimal Flavour Violation (MFV), in suppressing the strength of flavour-changing neutral-currents (FCNCs) in models with more than one Higgs doublet. We show that the MFV hypothesis, in its general formulation, is more stable in suppressing FCNCs than the hypothesis of NFC alone when quantum corrections are taken into account. The phenomenological implications of the two scenarios are discussed analysing meson-antimeson mixing observables and the rare decays B -> mu+ mu-. We demonstrate that, introducing flavour-blind CP phases, two-Higgs doublet models respecting the MFV hypothesis can accommodate a large CP-violating phase in Bs mixing, as hinted by CDF and D0 data and, without extra free parameters, soften significantly in a correlated manner the observed anomaly in the relation between epsilon_K and S_psi_K.Comment: 27 pages, 4 figures. v3: minor modifications (typos corrected and few refs. added), conclusions unchanged; journal versio

Sex-specific genetic effects influence variation in body composition

Aims/hypothesis: Despite well-known sex differences in body composition it is not known whether sex-specific genetic or environmental effects contribute to these differences. Methods: We assessed body composition in 2,506 individuals, from a young Dutch genetic isolate participating in the Erasmus Rucphen Family study, by dual-energy X-ray absorptiometry and anthropometry. We used variance decomposition procedures to partition variation of body composition into genetic and environmental components common to both sexes and to men and women separately and calculated the correlation between genetic components in men and women. Results: After accounting for age

Preventing the Reintroduction of Malaria in Mauritius: A Programmatic and Financial Assessment

Sustaining elimination of malaria in areas with high receptivity and vulnerability will require effective strategies to prevent reestablishment of local transmission, yet there is a dearth of evidence about this phase. Mauritius offers a uniquely informative history, with elimination of local transmission in 1969, re-emergence in 1975, and second elimination in 1998. Towards this end, Mauritius's elimination and prevention of reintroduction (POR) programs were analyzed via a comprehensive review of literature and government documents, supplemented by program observation and interviews with policy makers and program personnel. The impact of the country's most costly intervention, a passenger screening program, was assessed quantitatively using simulation modeling

A new molecular breast cancer subclass defined from a large scale real-time quantitative RT-PCR study

BACKGROUND: Current histo-pathological prognostic factors are not very helpful in predicting the clinical outcome of breast cancer due to the disease's heterogeneity. Molecular profiling using a large panel of genes could help to classify breast tumours and to define signatures which are predictive of their clinical behaviour. METHODS: To this aim, quantitative RT-PCR amplification was used to study the RNA expression levels of 47 genes in 199 primary breast tumours and 6 normal breast tissues. Genes were selected on the basis of their potential implication in hormonal sensitivity of breast tumours. Normalized RT-PCR data were analysed in an unsupervised manner by pairwise hierarchical clustering, and the statistical relevance of the defined subclasses was assessed by Chi2 analysis. The robustness of the selected subgroups was evaluated by classifying an external and independent set of tumours using these Chi2-defined molecular signatures. RESULTS: Hierarchical clustering of gene expression data allowed us to define a series of tumour subgroups that were either reminiscent of previously reported classifications, or represented putative new subtypes. The Chi2 analysis of these subgroups allowed us to define specific molecular signatures for some of them whose reliability was further demonstrated by using the validation data set. A new breast cancer subclass, called subgroup 7, that we defined in that way, was particularly interesting as it gathered tumours with specific bioclinical features including a low rate of recurrence during a 5 year follow-up. CONCLUSION: The analysis of the expression of 47 genes in 199 primary breast tumours allowed classifying them into a series of molecular subgroups. The subgroup 7, which has been highlighted by our study, was remarkable as it gathered tumours with specific bioclinical features including a low rate of recurrence. Although this finding should be confirmed by using a larger tumour cohort, it suggests that gene expression profiling using a minimal set of genes may allow the discovery of new subclasses of breast cancer that are characterized by specific molecular signatures and exhibit specific bioclinical features

A Randomized Trial of a Physical Conditioning Program to Enhance the Driving Performance of Older Persons

BACKGROUND: As the number of older drivers increases, concern has been raised about the potential safety implications. Flexibility, coordination, and speed of movement have been associated with older drivers’ on road performance. OBJECTIVE: To determine whether a multicomponent physical conditioning program targeted to axial and extremity flexibility, coordination, and speed of movement could improve driving performance among older drivers. DESIGN: Randomized controlled trial with blinded assignment and end point assessment. Participants randomized to intervention underwent graduated exercises; controls received home, environment safety modules. PARTICIPANTS: Drivers, 178, age ≥ 70 years with physical, but without substantial visual (acuity 20/40 or better) or cognitive (Mini Mental State Examination score ≥24) impairments were recruited from clinics and community sources. MEASUREMENTS: On-road driving performance assessed by experienced evaluators in dual-brake equipped vehicle in urban, residential, and highway traffic. Performance rated three ways: (1) 36-item scale evaluating driving maneuvers and traffic situations; (2) evaluator’s overall rating; and (3) critical errors committed. Driving performance reassessed at 3 months by evaluator blinded to treatment group. RESULTS: Least squares mean change in road test scores at 3 months compared to baseline was 2.43 points higher in intervention than control participants (P = .03). Intervention drivers committed 37% fewer critical errors (P = .08); there were no significant differences in evaluator’s overall ratings (P = .29). No injuries were reported, and complaints of pain were rare. CONCLUSIONS: This safe, well-tolerated intervention maintained driving performance, while controls declined during the study period. Having interventions that can maintain or enhance driving performance may allow clinician–patient discussions about driving to adopt a more positive tone, rather than focusing on driving limitation or cessation