99 research outputs found

    Rough droplet model for spherical metal clusters

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    We study the thermally activated oscillations, or capillary waves, of a neutral metal cluster within the liquid drop model. These deformations correspond to a surface roughness which we characterize by a single parameter Δ\Delta. We derive a simple analytic approximate expression determining Δ\Delta as a function of temperature and cluster size. We then estimate the induced effects on shell structure by means of a periodic orbit analysis and compare with recent data for shell energy of sodium clusters in the size range 50<N<25050 < N < 250. A small surface roughness Δ≃0.6\Delta\simeq 0.6 \AA~ is seen to give a reasonable account of the decrease of amplitude of the shell structure observed in experiment. Moreover -- contrary to usual Jahn-Teller type of deformations -- roughness correctly reproduces the shape of the shell energy in the domain of sizes considered in experiment.Comment: 20 pages, 4 figures, important modifications of the presentation, to appear in Phys. Rev.

    Exploring Cosmic Origins with CORE: The Instrument

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    We describe a space-borne, multi-band, multi-beam polarimeter aiming at aprecise and accurate measurement of the polarization of the Cosmic MicrowaveBackground. The instrument is optimized to be compatible with the strict budgetrequirements of a medium-size space mission within the Cosmic Vision Programmeof the European Space Agency. The instrument has no moving parts, and usesarrays of diffraction-limited Kinetic Inductance Detectors to cover thefrequency range from 60 GHz to 600 GHz in 19 wide bands, in the focal plane ofa 1.2 m aperture telescope cooled at 40 K, allowing for an accurate extractionof the CMB signal from polarized foreground emission. The projected CMBpolarization survey sensitivity of this instrument, after foregrounds removal,is 1.7 {\mu}K⋅\cdotarcmin. The design is robust enough to allow, if needed, adownscoped version of the instrument covering the 100 GHz to 600 GHz range witha 0.8 m aperture telescope cooled at 85 K, with a projected CMB polarizationsurvey sensitivity of 3.2 {\mu}K⋅\cdotarcmin

    Cancer Carepartners: Improving patients' symptom management by engaging informal caregivers

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    <p>Abstract</p> <p>Background</p> <p>Previous studies have found that cancer patients undergoing chemotherapy can effectively manage their own symptoms when given tailored advice. This approach, however, may challenge patients with poor performance status and/or emotional distress. Our goal is to test an automated intervention that engages a friend or family member to support a patient through chemotherapy.</p> <p>Methods/Design</p> <p>We describe the design and rationale of a randomized, controlled trial to assess the efficacy of 10 weeks of web-based caregiver alerts and tailored advice for helping a patient manage symptoms related to chemotherapy. The study aims to test the primary hypothesis that patients whose caregivers receive alerts and tailored advice will report less frequent and less severe symptoms at 10 and 14 weeks when compared to patients in the control arm; similarly, they will report better physical function, fewer outpatient visits and hospitalizations related to symptoms, and greater adherence to chemotherapy. 300 patients with solid tumors undergoing chemotherapy at two Veteran Administration oncology clinics reporting any symptom at a severity of ≄4 and a willing informal caregiver will be assigned to either 10 weeks of automated telephonic symptom assessment (ATSA) alone, or 10 weeks of ATSA plus web-based notification of symptom severity and problem solving advice to their chosen caregiver. Patients and caregivers will be surveyed at intake, 10 weeks and 14 weeks. Both groups will receive standard oncology, hospice, and palliative care.</p> <p>Discussion</p> <p>Patients undergoing chemotherapy experience many symptoms that they may be able to manage with the support of an activated caregiver. This intervention uses readily available technology to improve patient caregiver communication about symptoms and caregiver knowledge of symptom management. If successful, it could substantially improve the quality of life of veterans and their families during the stresses of chemotherapy without substantially increasing the cost of care.</p> <p>Trial Registration</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT00983892">NCT00983892</a></p

    Exploring Cosmic Origins with CORE: Survey requirements and mission design

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    Future observations of cosmic microwave background (CMB) polarisation havethe potential to answer some of the most fundamental questions of modernphysics and cosmology. In this paper, we list the requirements for a future CMBpolarisation survey addressing these scientific objectives, and discuss thedesign drivers of the CORE space mission proposed to ESA in answer to the "M5"call for a medium-sized mission. The rationale and options, and themethodologies used to assess the mission's performance, are of interest toother future CMB mission design studies. CORE is designed as a near-ultimateCMB polarisation mission which, for optimal complementarity with ground-basedobservations, will perform the observations that are known to be essential toCMB polarisation scienceand cannot be obtained by any other means than adedicated space mission

    A Phylogenetic Analysis of Human Immunodeficiency Virus Type 1 Sequences in Kiev: Findings Among Key Populations

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    Background: The human immunodeficiency virus (HIV) epidemic in Ukraine has been driven by a rapid rise among people who inject drugs, but recent studies have shown an increase through sexual transmission. Methods: Protease and reverse transcriptase sequences from 876 new HIV diagnoses (April 2013–March 2015) in Kiev were linked to demographic data. We constructed phylogenetic trees for 794 subtype A1 and 64 subtype B sequences and identified factors associated with transmission clustering. Clusters were defined as ≄2 sequences, ≄80% local branch support, and maximum genetic distance of all sequence pairs in the cluster ≀2.5%. Recent infection was determined through the limiting antigen avidity enzyme immunoassay. Sequences were analyzed for transmitted drug resistance mutations. Results Thirty percent of subtype A1 and 66% of subtype B sequences clustered. Large clusters (maximum 11 sequences) contained mixed risk groups. In univariate analysis, clustering was significantly associated with subtype B compared to A1 (odds ratio [OR], 4.38 [95% confidence interval {CI}, 2.56–7.50]); risk group (OR, 5.65 [95% CI, 3.27–9.75]) for men who have sex with men compared to heterosexual males; recent, compared to long-standing, infection (OR, 2.72 [95% CI, 1.64–4.52]); reported sex work contact (OR, 1.93 [95% CI, 1.07–3.47]); and younger age groups compared with age ≄36 years (OR, 1.83 [95% CI, 1.10–3.05] for age ≀25 years). Females were associated with lower odds of clustering than heterosexual males (OR, 0.49 [95% CI, .31–.77]). In multivariate analysis, risk group, subtype, and age group were independently associated with clustering (P < .001, P = .007, and P = .033, respectively). Eighteen sequences (2.1%) indicated evidence of transmitted drug resistance. Conclusions Our findings suggest high levels of transmission and bridging between risk groups

    Swiss students and young physicians want a flexible goal-oriented GP training curriculum.

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    A growing shortage of general practitioners (GPs), in Switzerland and around the world, has forced countries to find new ways to attract young physicians to the specialty. In 2017, Switzerland began to fund hundreds of new study places for medical students. This wave of young physicians will soon finish University and be ready for postgraduate training. We hypothesized that an attractive postgraduate training program would encourage interested young physicians to pursue a GP career. This is a cross-sectional survey of young physicians from the Swiss Young General Practitioners Association (JHaS), members of Cursus Romand de mĂ©decine de famille (CRMF), and all current medical students (5 &lt;sup&gt;th&lt;/sup&gt; or 6 &lt;sup&gt;th&lt;/sup&gt; years) (n = 554) in Switzerland, excluding students indicating definitely not to become GPs. We asked all if they were likely to become a GP (Likert: 1-10), and then asked them to score general features of a GP training curriculum, and likely effects of the curriculum on their career choice (Likert scale). They then rated our model curriculum (GO-GP) for attractiveness and effect (Likert Scales, open questions). Most participants thought they would become GPs (Likert: 8 of 10). Over 90% identified the same features as an important part of a curriculum ("yes" or "likely yes"): Our respondents thought the GO-GP curriculum was attractive (7.3 of 10). It was most attractive to those highly motivated to become GPs. After reviewing the curriculum, most respondents (58%) felt GO-GP would make them more likely to become a GP. Almost 80% of respondents thought an attractive postgraduate training program like GO-GP could motivate more young physicians to become GPs. Overall, medical students and young physicians found similar features attractive in the general and GO-GP curriculum, regardless of region or gender, and thought an attractive curriculum would attract more young doctors to the GP specialty. Key points An attractive postgraduate training program in general practice can attract more young physicians to become GPs. In this study cross-sectional survey including medical students (n = 242) and young physicians (n = 312) we presented general features for a curriculum and a model curriculum for general practice training, for evaluation of attractiveness to our study population. General practice training curriculum provides flexibility in choice of rotations, access to short rotations in a wide variety of medical specialties, training in specialty practices as well, mentoring and career guidance by GPs and guidance in choosing courses/certificate programs necessary for general practice. These findings help building attractive postgraduate training programs in general practice and fight GP shortage

    Exploring Cosmic Origins with CORE: Cosmological Parameters

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    We forecast the main cosmological parameter constraints achievable with theCORE space mission which is dedicated to mapping the polarisation of the CosmicMicrowave Background (CMB). CORE was recently submitted in response to ESA'sfifth call for medium-sized mission proposals (M5). Here we report the resultsfrom our pre-submission study of the impact of various instrumental options, inparticular the telescope size and sensitivity level, and review the great,transformative potential of the mission as proposed. Specifically, we assessthe impact on a broad range of fundamental parameters of our Universe as afunction of the expected CMB characteristics, with other papers in the seriesfocusing on controlling astrophysical and instrumental residual systematics. Inthis paper, we assume that only a few central CORE frequency channels areusable for our purpose, all others being devoted to the cleaning ofastrophysical contaminants. On the theoretical side, we assume LCDM as ourgeneral framework and quantify the improvement provided by CORE over thecurrent constraints from the Planck 2015 release. We also study the jointsensitivity of CORE and of future Baryon Acoustic Oscillation and Large ScaleStructure experiments like DESI and Euclid. Specific constraints on the physicsof inflation are presented in another paper of the series. In addition to thesix parameters of the base LCDM, which describe the matter content of aspatially flat universe with adiabatic and scalar primordial fluctuations frominflation, we derive the precision achievable on parameters like thosedescribing curvature, neutrino physics, extra light relics, primordial heliumabundance, dark matter annihilation, recombination physics, variation offundamental constants, dark energy, modified gravity, reionization and cosmicbirefringence. (ABRIDGED
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