131 research outputs found
In Reply to the Letter to the Editor Regarding "Distribution of Psychological Instability Among Surgeons".
peer reviewe
Kinetics of Graphene Growth on Liquid Copper by Chemical Vapor Deposition
We report a combined experimental and computational study of the kinetics of
graphene growth during chemical vapor deposition on a liquid copper catalyst.
The use of liquid metal catalysts offers bright perspectives for controllable
large-scale, high-quality synthesis technologies of two-dimensional materials.
We carried out a series of growth experiments varying CH4-to-H2 pressure ratios
and deposition temperature. By monitoring the graphene flake morphology in real
time during growth using in situ optical microscopy in radiation mode, we
explored the morphology and kinetics of the growth within a wide range of
experimental conditions. Following an analysis of the flakes' growth rates, we
conclude that the growth mode was attachment-limited. The attachment and
detachment activation energies of carbon species are derived as 1.9 +- 0.3 eV
and 2.0 +- 0.1 eV, respectively. We also conducted free-energy calculations by
a moment tensor potential trained to density functional theory data. Our
simulations propose that carbon dimers are most likely the active carbon
species during growth, with attachment and detachment barriers of 1.71 +- 0.15
eV and 2.09 +- 0.02 eV, respectively, being in good agreement with the
experimental results
Distribution of Psychological Instability Among Surgeons.
peer reviewed[en] BACKGROUND: High emotional instability (i.e., neuroticism) is associated with poor mental health. Conversely, traumatic experiences may increase neuroticism. Stressful experiences such as complications are common in the surgical profession, with neurosurgeons being particularly affected. We compared the personality trait neuroticism between physicians in a prospective cross-sectional study.
METHODS: We used an online survey using the Ten-Item Personality Inventory, an internationally validated measure of the 5-factor model of personality dimensions. It was distributed to board-certified physicians, residents, and medical students in several European countries and Canada (n = 5148). Multivariate linear regression was used to model differences between surgeons, nonsurgeons, and specialties with occasional surgical interventions with respect to neuroticism, adjusting for sex, age, age squared, and their interactions, then testing equality of parameters of adjusted predictions separately and jointly using Wald tests.
RESULTS: With an expected variability within disciplines, average levels of neuroticism are lower in surgeons than nonsurgeons, especially in the first part of their career. However, the course of neuroticism across age follows a quadratic pattern, that is, an increase after the initial decrease. The acceleration of neuroticism with age is specifically significant in surgeons. Levels of neuroticism are lowest towards mid-career, but exhibit a strong secondary increase towards the end of the surgeon's career. This pattern seems driven by neurosurgeons.
CONCLUSIONS: Despite initially lower levels of neuroticism, surgeons suffer a stronger increase of neuroticism together with age. Because, beyond well-being, neuroticism influences professional performance and health care systems costs, explanatory studies are mandatory to enlighten causes of this burden
Distribution of psychological instability among surgeons
Background High emotional instability, i.e. neuroticism, is associated with poor mental health. Conversely, traumatic experiences may increase neuroticism. Stressful experiences such as complications are common in the surgical profession, with neurosurgeons being particularly affected. We compared the personality trait neuroticism between physicians in a prospective cross-sectional study. Methods 5,148). Multivariate linear regression was used to model differences between surgeons, non-surgeons and specialties with occasional surgical interventions with respect to neuroticism, adjusting for gender, age, age squared and their interactions, then testing equality of parameters of adjusted predictions separately and jointly using Wald tests. Results With an expected variability within disciplines, average levels of neuroticism are lower in surgeons than non-surgeons, especially in the first part of their career. However, the course of neuroticism across age follows a quadratic pattern, i.e., an increase after the initial decrease. The acceleration of neuroticism with age is specifically significant in surgeons. Levels of neuroticism are lowest towards mid-career, but exhibit a strong secondary increase towards the end of the surgeonsâ career. This pattern seems driven by neurosurgeons. Conclusion Despite initially lower levels of neuroticism, surgeons suffer a stronger increase of neuroticism together with age. Since, beyond well-being, neuroticism influences professional performance and healthcare systems costs, explanatory studies are mandatory to enlighten causes of this burden
Copy number and gene expression differences between African American and Caucasian American prostate cancer
<p>Abstract</p> <p>Background</p> <p>The goal of our study was to investigate the molecular underpinnings associated with the relatively aggressive clinical behavior of prostate cancer (PCa) in African American (AA) compared to Caucasian American (CA) patients using a genome-wide approach.</p> <p>Methods</p> <p>AA and CA patients treated with radical prostatectomy (RP) were frequency matched for age at RP, Gleason grade, and tumor stage. Array-CGH (BAC SpectralChip2600) was used to identify genomic regions with significantly different DNA copy number between the groups. Gene expression profiling of the same set of tumors was also evaluated using Affymetrix HG-U133 Plus 2.0 arrays. Concordance between copy number alteration and gene expression was examined. A second aCGH analysis was performed in a larger validation cohort using an oligo-based platform (Agilent 244K).</p> <p>Results</p> <p>BAC-based array identified 27 chromosomal regions with significantly different copy number changes between the AA and CA tumors in the first cohort (Fisher's exact test, P < 0.05). Copy number alterations in these 27 regions were also significantly associated with gene expression changes. aCGH performed in a larger, independent cohort of AA and CA tumors validated 4 of the 27 (15%) most significantly altered regions from the initial analysis (3q26, 5p15-p14, 14q32, and 16p11). Functional annotation of overlapping genes within the 4 validated regions of AA/CA DNA copy number changes revealed significant enrichment of genes related to immune response.</p> <p>Conclusions</p> <p>Our data reveal molecular alterations at the level of gene expression and DNA copy number that are specific to African American and Caucasian prostate cancer and may be related to underlying differences in immune response.</p
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
Recommended from our members
Report on the sixth blind test of organic crystal structure prediction methods.
The sixth blind test of organic crystal structure prediction (CSP) methods has been held, with five target systems: a small nearly rigid molecule, a polymorphic former drug candidate, a chloride salt hydrate, a co-crystal and a bulky flexible molecule. This blind test has seen substantial growth in the number of participants, with the broad range of prediction methods giving a unique insight into the state of the art in the field. Significant progress has been seen in treating flexible molecules, usage of hierarchical approaches to ranking structures, the application of density-functional approximations, and the establishment of new workflows and `best practices' for performing CSP calculations. All of the targets, apart from a single potentially disordered Z' = 2 polymorph of the drug candidate, were predicted by at least one submission. Despite many remaining challenges, it is clear that CSP methods are becoming more applicable to a wider range of real systems, including salts, hydrates and larger flexible molecules. The results also highlight the potential for CSP calculations to complement and augment experimental studies of organic solid forms.The organisers and participants are very grateful to the crystallographers who supplied the candidate structures: Dr. Peter Horton (XXII), Dr. Brian Samas (XXIII), Prof. Bruce Foxman (XXIV), and Prof. Kraig Wheeler (XXV and XXVI). We are also grateful to Dr. Emma Sharp and colleagues at Johnson Matthey (Pharmorphix) for the polymorph screening of XXVI, as well as numerous colleagues at the CCDC for assistance in organising the blind test. Submission 2: We acknowledge Dr. Oliver Korb for numerous useful discussions. Submission 3: The Day group acknowledge the use of the IRIDIS High Performance Computing Facility, and associated support services at the University of Southampton, in the completion of this work. We acknowledge funding from the EPSRC (grants EP/J01110X/1 and EP/K018132/1) and the European Research Council under the European Unionâs Seventh Framework Programme (FP/2007-2013)/ERC through grant agreements n. 307358 (ERC-stG- 2012-ANGLE) and n. 321156 (ERC-AG-PE5-ROBOT). Submission 4: I am grateful to Mikhail Kuzminskii for calculations of molecular structures on Gaussian 98 program in the Institute of Organic Chemistry RAS. The Russian Foundation for Basic Research is acknowledged for financial support (14-03-01091). Submission 5: Toine Schreurs provided computer facilities and assistance. I am grateful to Matthew Habgood at AWE company for providing a travel grant. Submission 6: We would like to acknowledge support of this work by GlaxoSmithKline, Merck, and Vertex. Submission 7: The research was financially supported by the VIDI Research Program 700.10.427, which is financed by The Netherlands Organisation for Scientific Research (NWO), and the European Research Council (ERC-2010-StG, grant agreement n. 259510-KISMOL). We acknowledge the support of the Foundation for Fundamental Research on Matter (FOM). Supercomputer facilities were provided by the National Computing Facilities Foundation (NCF). Submission 8: Computer resources were provided by the Center for High Performance Computing at the University of Utah and the Extreme Science and Engineering Discovery Environment (XSEDE), supported by NSF grant number ACI-1053575. MBF and GIP acknowledge the support from the University of Buenos Aires and the Argentinian Research Council. Submission 9: We thank Dr. Bouke van Eijck for his valuable advice on our predicted structure of XXV. We thank the promotion office for TUT programs on advanced simulation engineering (ADSIM), the leading program for training brain information architects (BRAIN), and the information and media center (IMC) at Toyohashi University of Technology for the use of the TUT supercomputer systems and application software. We also thank the ACCMS at Kyoto University for the use of their supercomputer. In addition, we wish to thank financial supports from Conflex Corp. and Ministry of Education, Culture, Sports, Science and Technology. Submission 12: We thank Leslie Leiserowitz from the Weizmann Institute of Science and Geoffrey Hutchinson from the University of Pittsburgh for helpful discussions. We thank Adam Scovel at the Argonne Leadership Computing Facility (ALCF) for technical support. Work at Tulane University was funded by the Louisiana Board of Regents Award # LEQSF(2014-17)-RD-A-10 âToward Crystal Engineering from First Principlesâ, by the NSF award # EPS-1003897 âThe Louisiana Alliance for Simulation-Guided Materials Applications (LA-SiGMA)â, and by the Tulane Committee on Research Summer Fellowship. Work at the Technical University of Munich was supported by the Solar Technologies Go Hybrid initiative of the State of Bavaria, Germany. Computer time was provided by the Argonne Leadership Computing Facility (ALCF), which is supported by the Office of Science of the U.S. Department of Energy under contract DE-AC02-06CH11357. Submission 13: This work would not have been possible without funding from Khalifa Universityâs College of Engineering. I would like to acknowledge Prof. Robert Bennell and Prof. Bayan Sharif for supporting me in acquiring the resources needed to carry out this research. Dr. Louise Price is thanked for her guidance on the use of DMACRYS and NEIGHCRYS during the course of this research. She is also thanked for useful discussions and numerous e-mail exchanges concerning the blind test. Prof. Sarah Price is acknowledged for her support and guidance over many years and for providing access to DMACRYS and NEIGHCRYS. Submission 15: The work was supported by the United Kingdomâs Engineering and Physical Sciences Research Council (EPSRC) (EP/J003840/1, EP/J014958/1) and was made possible through access to computational resources and support from the High Performance Computing Cluster at Imperial College London. We are grateful to Professor Sarah L. Price for supplying the DMACRYS code for use within CrystalOptimizer, and to her and her research group for support with DMACRYS and feedback on CrystalPredictor and CrystalOptimizer. Submission 16: R. J. N. acknowledges financial support from the Engineering and Physical Sciences Research Council (EPSRC) of the U.K. [EP/J017639/1]. R. J. N. and C. J. P. acknowledge use of the Archer facilities of the U.K.âs national high-performance computing service (for which access was obtained via the UKCP consortium [EP/K014560/1]). C. J. P. also acknowledges a Leadership Fellowship Grant [EP/K013688/1]. B. M. acknowledges Robinson College, Cambridge, and the Cambridge Philosophical Society for a Henslow Research Fellowship. Submission 17: The work at the University of Delaware was supported by the Army Research Office under Grant W911NF-13-1- 0387 and by the National Science Foundation Grant CHE-1152899. The work at the University of Silesia was supported by the Polish National Science Centre Grant No. DEC-2012/05/B/ST4/00086. Submission 18: We would like to thank Constantinos Pantelides, Claire Adjiman and Isaac Sugden of Imperial College for their support of our use of CrystalPredictor and CrystalOptimizer in this and Submission 19. The CSP work of the group is supported by EPSRC, though grant ESPRC EP/K039229/1, and Eli Lilly. The PhD students support: RKH by a joint UCL Max-Planck Society Magdeburg Impact studentship, REW by a UCL Impact studentship; LI by the Cambridge Crystallographic Data Centre and the M3S Centre for Doctoral Training (EPSRC EP/G036675/1). Submission 19: The potential generation work at the University of Delaware was supported by the Army Research Office under Grant W911NF-13-1-0387 and by the National Science Foundation Grant CHE-1152899. Submission 20: The work at New York University was supported, in part, by the U.S. Army Research Laboratory and the U.S. Army Research Office under contract/grant number W911NF-13-1-0387 (MET and LV) and, in part, by the Materials Research Science and Engineering Center (MRSEC) program of the National Science Foundation under Award Number DMR-1420073 (MET and ES). The work at the University of Delaware was supported by the U.S. Army Research Laboratory and the U.S. Army Research Office under contract/grant number W911NF-13-1- 0387 and by the National Science Foundation Grant CHE-1152899. Submission 21: We thank the National Science Foundation (DMR-1231586), the Government of Russian Federation (Grant No. 14.A12.31.0003), the Foreign Talents Introduction and Academic Exchange Program (No. B08040) and the Russian Science Foundation, project no. 14-43-00052, base organization Photochemistry Center of the Russian Academy of Sciences. Calculations were performed on the Rurik supercomputer at Moscow Institute of Physics and Technology. Submission 22: The computational results presented have been achieved in part using the Vienna Scientific Cluster (VSC). Submission 24: The potential generation work at the University of Delaware was supported by the Army Research Office under Grant W911NF-13-1-0387 and by the National Science Foundation Grant CHE-1152899. Submission 25: J.H. and A.T. acknowledge the support from the Deutsche Forschungsgemeinschaft under the program DFG-SPP 1807. H-Y.K., R.A.D., and R.C. acknowledge support from the Department of Energy (DOE) under Grant Nos. DE-SC0008626. This research used resources of the Argonne Leadership Computing Facility at Argonne National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-06CH11357. This research used resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DEAC02-05CH11231. Additional computational resources were provided by the Terascale Infrastructure for Groundbreaking Research in Science and Engineering (TIGRESS) High Performance Computing Center and Visualization Laboratory at Princeton University.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1107/S2052520616007447
Report on the sixth blind test of organic crystal-structure prediction methods
The sixth blind test of organic crystal-structure prediction (CSP) methods has been held, with five target systems: a small nearly rigid molecule, a polymorphic former drug candidate, a chloride salt hydrate, a co-crystal, and a bulky flexible molecule. This blind test has seen substantial growth in the number of submissions, with the broad range of prediction methods giving a unique insight into the state of the art in the field. Significant progress has been seen in treating flexible molecules, usage of hierarchical approaches to ranking structures, the application of density-functional approximations, and the establishment of new workflows and "best practices" for performing CSP calculations. All of the targets, apart from a single potentially disordered Z` = 2 polymorph of the drug candidate, were predicted by at least one submission. Despite many remaining challenges, it is clear that CSP methods are becoming more applicable to a wider range of real systems, including salts, hydrates and larger flexible molecules. The results also highlight the potential for CSP calculations to complement and augment experimental studies of organic solid forms
Interventions aimed at preventing and reducing overweight/obesity among children and adolescents:a meta-synthesis
The prevalence of child and adolescent obesity has been a major worldwide problem for decades. To stop the number of youth with overweight/obesity from increasing, numerous interventions focusing on improving children's weight status have been implemented. The growing body of research on weight-related interventions for youth has been summarized by several meta-analyses aiming to provide an overview of the effectiveness of interventions. Yet, the number of meta-analyses is expanding so quickly and overall results differ, making a comprehensive synopsis of the literature difficult. To tackle this problem, a meta-synthesis was conducted to draw informed conclusions about the state of the effectiveness of interventions targeting child and adolescent overweight. The results of the quantitative synthesis of 26 meta-analyses resulted in a standardized mean difference (SMD) of -0.12 (95%CI: -0.16, -0.08). Several moderator analyses showed that participant and intervention characteristics had little impact on the overall effect size. However, a moderator analysis distinguishing between obesity treatment and obesity prevention studies showed that obesity treatment interventions (SMD: -0.048, 95%CI: -0.60, -0.36) were significantly more effective in reducing body mass index than obesity prevention interventions (SMD: -0.08, 95%CI: -0.11, -0.06). Overall, the results of this meta-synthesis suggest that interventions result in statistically significant effects albeit of relatively little clinical relevance
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