148 research outputs found

    Analysis of generalized negative binomial distributions attached to hyperbolic Landau levels

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    To each hyperbolic Landau level of the Poincar\'e disc is attached a generalized negative binomial distribution. In this paper, we compute the moment generating function of this distribution and supply its decomposition as a perturbation of the negative binomial distribution by a finitely-supported measure. Using the Mandel parameter, we also discuss the nonclassical nature of the associated coherent states. Next, we determine the L\'evy-Kintchine decomposition its characteristic function when the latter does not vanish and deduce that it is quasi-infinitely divisible except for the lowest hyperbolic Landau level corresponding to the negative binomial distribution. By considering the total variation of the obtained quasi-L\'evy measure, we introduce a new infinitely-divisible distribution for which we derive the characteristic function

    Distribution of the different species of the Pseudallescheria boydii/Scedosporium apiospermum complex in French patients with cystic fibrosis

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    As various new sibling species within the Pseudallescheria boydii/Scedosporium apiospermum complex have been described recently with differences in their susceptibility to antifungals, this study was conducted in order to determine their respective frequency in cystic fibrosis. Results indicated that P. boydii largely predominated (62%), followed by S. apiospermum (24%), Scedosporium aurantiacum (10%) and Pseudallescheria minutispora (4%). Scedosporium dehoogii was not recovered in this study. The multiple correspondence factor analysis highlighted geographical discrepancies within species distribution: P. boydii was rarely encountered in Northern France, while S. apiospermum was less represented in the west of the country. Additionally, we demonstrated that all species encountered in the cystic fibrosis context were capable to chronically colonize the respiratory tract of patients. Molecular typing of a large set of environmental and clinical isolates should be conducted to delineate the epidemiology of each sibling species in the complex

    Prevalence of the sibling species of the Scedosporium apiospermum complex in cystic fibrosis context

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    Objectives: Cystic fibrosis is the most common genetic inherited disease in the European Caucasian population (frequency 1 out of 2500 births). Disease causes are mutations in the CFTR (cystic fibrosis transmembrane conductance regulator) gene, which encodes a chloride channel in the plasma membrane of several epithelial cells. However, prognosis essentially depends on the severity of the lesions in the lungs. The defective mucociliary clearance and the thickening of the bronchial mucus resulting from these mutations facilitate the entrapment of airborne microbes. Patients with such chronic pulmonary defect are at high risk for colonizations/infections by fungi, including the emergent pathogens of the Scedoporium apiospermum complex. This species complex ranks the second among the filamentous fungi colonizing the airways of CF patients. Recent molecular studies supported by morphological, physiological and genetic observations showed that the S. apiospermum complex comprises at least five distinct species. Antifungal susceptibility profiles and virulence of these sibling species showed differences. This study aims to determine the prevalence of the different species of S. apiospermum complex in the CF context and to analyze the chronic trait of these infections. Methods: A set of 50 epidemiologically unrelated isolates was analyzed to estimate the prevalence, all isolates having been recovered from distinct patients with CF followed up in different university hospitals from France and initially identified as belonging to the S. apiospermum complex. The internal transcribed spacer (ITS) regions 1 and 2 of the ribosomal RNA gene, a fragment of the nuclear gene calmodulin (CAL) and two regions (BT2 and TUB) within the ß-tubulin gene were amplified and sequenced as described by Gilgado et al. Additionally, sequential (from successive sputum samples from the same patient) and multiple (from the same clinical sample) isolates were genotyped by random amplification of polymorphic DNA (RAPD) using primers GC70, UBC-701 and UBC-703. Results and conclusion: Pseudallescheria boydii was the most common specie encountered (62% of the isolates) in the CF context, followed by S. apiospermum sensu stricto (24%) and S. aurantiacum (10%). These results contrast with the natural occurrence of these species in the environment, reinforcing the need for further studies aiming to elucidate the pathogenic mechanisms of these fungi. As reported by Kalsteis et al., S. apiospermum sensu stricto is the most prevalent specie in the environment, accounting for 58.7–77.7% of the isolates (depending on the habitat studied), while low prevalence were found for S. aurantiacum and P. boydii, which represented 4.8 (industrial areas) to 7.7% (parks and playgrounds) and 1.9–2.3% of the isolates, respectively. Likewise, Scedosporium dehoogii, which represented about 13.8–28.8% of the isolates from environmental samples, has not been described in a clinical context as yet. Moreover, our results suggest a clustering according to the geographic origin of the isolates: CF patients from the West of France were predominantly colonized by P. boydii. Events of chronic colonization were observed for each specie of S. apiospermum complex encountered in CF context. The RAPD genotyping demonstrated also that two different species could concomitantly colonize the same patient.

    The global oscillation network group site survey. II. Results

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    The Global Oscillation Network Group (GONG) Project will place a network of instruments around the world to observe solar oscillations as continuously as possible for three years. The Project has now chosen the six network sites based on analysis of survey data from fifteen sites around the world. The chosen sites are: Big Bear Solar Observatory, California; Mauna Loa Solar Observatory, Hawaii; Learmonth Solar Observatory, Australia; Udaipur Solar Observatory, India; Observatorio del Teide, Tenerife; and Cerro Tololo Interamerican Observatory, Chile. Total solar intensity at each site yields information on local cloud cover, extinction coefficient, and transparency fluctuations. In addition, the performance of 192 reasonable components analysis. An accompanying paper describes the analysis methods in detail; here we present the results of both the network and individual site analyses. The selected network has a duty cycle of 93.3%, in good agreement with numerical simulations. The power spectrum of the network observing window shows a first diurnal sidelobe height of 3 × 10⁻⁴ with respect to the central component, an improvement of a factor of 1300 over a single site. The background level of the network spectrum is lower by a factor of 50 compared to a single-site spectrum

    Factors affecting medical students in formulating their specialty preferences in Jordan

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    <p>Abstract</p> <p>Background</p> <p>In recent years there has been a growing appreciation of the issues of career preference in medicine as it may affect student learning and academic performance. However, no such studies have been undertaken in medical schools in Jordan. Therefore, we carried out this study to investigate the career preferences of medical students at Jordan University of Science and Technology and determine factors that might influence their career decisions.</p> <p>Methods</p> <p>A cross-sectional questionnaire-based survey was carried out among second, fourth and sixth year medical students at the Jordan University of Science and Technology, Irbid, Jordan during the academic year 2006/2007. A total of 440 students answered the questionnaire which covered demographic characteristics, specialty preferences, and the factors that influenced these career preferences. Possible influences were selected on the basis of a literature review and discussions with groups of medical students and physicians. Students were asked to consider 14 specialty options and select the most preferred career preference.</p> <p>Results</p> <p>The most preferred specialty expressed by male students was surgery, followed by internal medicine and orthopaedics, while the specialty most preferred by female students was obstetrics and gynaecology, followed by pediatrics and surgery. Students showed little interest in orthopedics, ophthalmology, and dermatology. While 3.1% of females expressed interest in anesthesiology, no male students did. Other specialties were less attractive to most students.</p> <p>Intellectual content of the specialty and the individual's competencies were the most influential on their preference of specialty. Other influential factors were the "reputation of the specialty", "anticipated income", and "focus on urgent care".</p> <p>Conclusion</p> <p>Surgery, internal medicine, pediatrics, and obstetrics and gynaecology were the most preferred specialty preferences of medical students at Jordan University of Science and Technology.</p

    VaTEST III : validation of 8 potential super-earths from TESS data

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    Funding: The ULiege’s contribution to SPECULOOS has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013) (grant Agreement n◦ 336480/SPECULOOS). This research is in part funded by the European Union’s Horizon 2020 research and innovation programme (grants agreements n◦ 803193/BEBOP), and from the Science and Technology Facilities Council (STFC; grant n◦ ST/S00193X/1, and ST/W000385/1).NASA’s all-sky survey mission, the Transiting Exoplanet Survey Satellite (TESS), is specifically engineered to detect exoplanets that transit bright stars. Thus far, TESS has successfully identified approximately 400 transiting exoplanets, in addition to roughly 6 000 candidate exoplanets pending confirmation. In this study, we present the results of our ongoing project, the Validation of Transiting Exoplanets using Statistical Tools (VaTEST). Our dedicated effort is focused on the confirmation and characterisation of new exoplanets through the application of statistical validation tools. Through a combination of ground-based telescope data, high-resolution imaging, and the utilisation of the statistical validation tool known as TRICERATOPS, we have successfully discovered eight potential super-Earths. These planets bear the designations: TOI-238b (1.61 +0.09−0.10 R ⊕ ), TOI-771b (1.42 +0.11−0.09 R ⊕ ), TOI-871b (1.66 +0.11−0.11 R ⊕ ), TOI-1467b (1.83 +0.16−0.15 R ⊕ ), TOI-1739b (1.69 +0.10−0.08 R ⊕ ), TOI-2068b (1.82 +0.16−0.15 R ⊕ ), TOI-4559b (1.42 +0.13−0.11 R ⊕ ), and TOI-5799b (1.62 +0.19−0.13 R ⊕ ). Among all these planets, six of them fall within the region known as ‘keystone planets’, which makes them particularly interesting for study. Based on the location of TOI-771b and TOI-4559b below the radius valley we characterised them as likely super-Earths, though radial velocity mass measurements for these planets will provide more details about their characterisation. It is noteworthy that planets within the size range investigated herein are absent from our own solar system, making their study crucial for gaining insights into the evolutionary stages between Earth and Neptune.Peer reviewe

    CPT-11 and concomitant hyperfractionated accelerated radiotherapy induce efficient local control in rectal cancer patients: results from a phase II

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    Patients with rectal cancer are at high risk of disease recurrence despite neoadjuvant radiochemotherapy with 5-Fluorouracil (5FU), a regimen that is now widely applied. In order to develop a regimen with increased antitumour activity, we previously established the recommended dose of neoadjuvant CPT-11 (three times weekly 90 mg m−2) concomitant to hyperfractionated accelerated radiotherapy (HART) followed by surgery within 1 week. Thirty-three patients (20 men) with a locally advanced adenocarcinoma of the rectum were enrolled in this prospective phase II trial (1 cT2, 29 cT3, 3 cT4 and 21 cN+). Median age was 60 years (range 43–75 years). All patients received all three injections of CPT-11 and all but two patients completed radiotherapy as planned. Surgery with total mesorectal excision (TME) was performed within 1 week (range 2–15 days). The preoperative chemoradiotherapy was overall well tolerated, 24% of the patients experienced grade 3 diarrhoea that was easily manageable. At a median follow-up of 2 years no local recurrence occurred, however, nine patients developed distant metastases. The 2-year disease-free survival was 66% (95% confidence interval 0.48–0.83). Neoadjuvant CPT-11 and HART allow for excellent local control; however, distant relapse remains a concern in this patient population

    Perovskite Solar Cells with Carbon-Based Electrodes – Quantification of Losses and Strategies to Overcome Them

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    Funder: UNIQUEFunder: National University of Ireland Travelling StudentshipFunder: Engineering and Physical Sciences Research Council; Id: http://dx.doi.org/10.13039/501100000266Funder: Cambridge Trust ScholarshipFunder: Robert Gardiner ScholarshipCarbon-based electrodes represent a promising approach to improve stability and up-scalability of perovskite photovoltaics. The temperature at which these contacts are processed defines the absorber grain size of the perovskite solar cell: in cells with low-temperature carbon-based electrodes (L-CPSCs), layer-by-layer deposition is possible, allowing perovskite crystals to be large (>100 nm), while in cells with high-temperature carbon-based contacts (H-CPSCs), crystals are constrained to 10-20 nm size. To enhance the power conversion efficiency of these devices, the main loss mechanisms were identified for both systems. Measurements of charge carrier lifetime, quasi-Fermi level splitting (QFLS) and light-intensity-dependent behavior, supported by numerical simulations, clearly demonstrate that H-CPSCs strongly suffer from non-radiative losses in the perovskite absorber, primarily due to numerous grain boundaries. In contrast, large crystals of L-CPSCs provide long carrier lifetime (1.8 µs) and exceptionally high QFLS of 1.21 eV for an absorber bandgap of 1.6 eV. These favorable characteristics explain the remarkable open-circuit voltage (VOC) of over 1.1 V in hole-selective layer-free L-CPSCs. However, the low photon absorption and poor charge transport in these cells limit their potential. Finally, effective strategies are provided to reduce non-radiative losses in H-CPSCs, transport losses in L-CPSCs and to improve photon management in both cell types.This work has been partially funded within the projects PROPER financed from the German Ministry of Education and Research under funding number 01DR19007 and UNIQUE supported under umbrella of SOLAR-ERA.NET_cofund by ANR, PtJ, MIUR, MINECO-AEI and SWEA, within the EU's HORIZON 2020 Research and Innovation Program (cofund ERA-NET Action No. 691664). D. B. acknowledges the scholarship support of the German Federal Environmental Foundation (DBU) and S. Z. acknowledges the scholarship support of the German Academic Exchange Service (DAAD). B.Y. and A.Ha. acknowledge the funding from the European Union’s Horizon 2020 research and innovation program ESPRESSO under the agreement No.: 764047. This work has also been partially funded by Swiss National Science Foundation with Project No. 200020_185041. T.D. acknowledges a National University of Ireland Travelling Studentship. K.F. acknowledges a George and Lilian Schiff Studentship, Winton Studentship, the Engineering and Physical Sciences Research Council (EPSRC) studentship, Cambridge Trust Scholarship, and Robert Gardiner Scholarship. S.S. acknowledges support from the Royal Society and Tata Group (UF150033). M.A. acknowledges funding from the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No.841386. The authors would like to thank Maryamsadat Heydarian and Laura Stevens for their EQE and AFM measurements. The authors thank the EPSRC (EP/R023980/1) for funding

    Concomitant use of tamoxifen with radiotherapy enhances subcutaneous breast fibrosis in hypersensitive patients

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    Concomitant use of adjuvant tamoxifen (TAM) and radiation therapy (RT) is not widely accepted. We aim to assess whether this treatment is associated with an increased risk of developing subcutaneous fibrosis after conservative or radical surgery in breast cancer patients. We analysed 147 women with breast cancer treated with adjuvant RT, and who were included in the KFS 00539-9-1997/SKL 00778-2-1999 prospective study aimed at evaluating the predictive value of CD4 and CD8 T-lymphocyte apoptosis for the development of radiation-induced late effects. TAM (20 mg day(-1)) with concomitant RT was prescribed in 90 hormone receptor-positive patients. There was a statistically significant difference in terms of complication-relapse-free survival (CRFS) rates at 3 years, 48% (95% CI 37.2-57.6%) vs 66% (95% CI 49.9-78.6%) and complication-free survival (CFS) rates at 2 years, 51% (95% CI 40-61%) vs 80% (95% CI 67-89%) in the TAM and no-TAM groups, respectively. In each of these groups, the CRFS rates were significantly lower for patients with low levels of CD8 radiation-induced apoptosis, 20% (95% CI 10-31.9%), 66% (95% CI 51.1-77.6%), and 79% (95% CI 55-90.9%) for CD8 &lt;/=16, 16-24, and &gt;24%, respectively. Similar results were observed for the CFS rates. The concomitant use of TAM with RT is significantly associated with an increased incidence of grade 2 or greater subcutaneous fibrosis; therefore, caution is needed for radiosensitive patients
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