623 research outputs found
Elastic constants of thorium single crystals
Values for the elastic constants c11 , c12 and c44 of thorium were determined over the temperature range from 80 to 370 degrees K. by ultrasonic measurements on single crystals. Two crystals were prepared by the strain anneal method. One crystal was cut in the form of a circular plate about 0.7 inch in diameter and 0.06 inch thick. The [111] direction of the crystal was perpendicular to the sample face. Measurements on this crystal with a resonance technique produced values for the stiffness coefficient in the [111] direction. This stiffness coefficient is a function of all three elastic constants
Robotic proctectomy for rectal cancer: analysis of 71 patients from a single institution
BackgroundDespite increasing use of robotic surgery for rectal cancer, few series have been published from the practice of generalizable US surgeons.MethodsA retrospective chart review was performed for 71 consecutive patients who underwent robotic low anterior resection (LAR) or abdominoperineal resection (APR) for rectal adenocarcinoma between 2010 and 2014.Results46 LARs (65%) and 25 APRs (35%) were identified. Median procedure time was 219 minutes (IQR 184–275) and mean blood loss 164.9 cc (SD 155.9 cc). Radial margin was negative in 70/71 (99%) patients. Total mesorectal excision integrity was complete/near complete in 38/39 (97%) of graded specimens. A mean of 16.8 (SD+/− 8.9) lymph nodes were retrieved. At median follow‐up of 21.9 months, there were no local recurrences.ConclusionsRobotic proctectomy for rectal cancer was introduced into typical colorectal surgery practice by a single surgeon, with a low conversion rate, low complication rate, and satisfactory oncologic outcomes.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139933/1/rcs1841_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139933/2/rcs1841.pd
The Evolution of Financial Structure in the G-7 Over 1997-2010
As background for this special issue of the Review, this article provides an overview of recent developments in financial structure in the major industrial countries using national flow of funds balance sheet data. We focus in particular on changes in the size and composition of the balance sheet for the major sectors - households, companies, general government, foreign and financial as well as banks and institutional investors separately. Two recent subperiods are distinguished, namely the “great moderation” of high growth and low inflation from roughly 1997-2006 and then the crisis period 2007-2010. We discern elements of convergence – notably in corporate leverage - but also some continuing contrasts – such as household debt - between “market” and “bank” dominated financial systems, while highlighting that short run changes arising from the conjuncture may blur longer term trends in financial structure. Looking ahead, the data highlight common challenges from public and household debt, albeit to an extent that varies markedly between countries. Bank deleveraging and recapitalisation appear slow, while a subsector including shadow banks continue to grow except in the US. There are contrasts between France and Italy on the one hand and Germany on the other which underline the vulnerability of the former in the ongoing Eurozone crisi
Reduction in Overall Occurrences of Ischemic Events with Vorapaxar: Results from TRACER
BACKGROUND: Clinical trials traditionally use time-to-first-event analysis embedded within the composite endpoint of cardiovascular death (CVD), myocardial infarction (MI), or stroke. However, many patients have \u3e1 event, and this approach may not reflect overall experience. We addressed this by analyzing all cardiovascular events in TRACER.
METHODS AND RESULTS: TRACER randomized 12 944 patients with non-ST-segment elevation acute coronary syndromes to placebo or to protease-activated receptor 1 antagonist vorapaxar with a median follow-up of 502 days (interquartile range, 349 to 667). Analysis of vorapaxar\u27s effect on recurrent CVD, MI, or stroke was prespecified using the Wei, Lin, and Weissfeld approach. Vorapaxar did not reduce the first occurrence of the primary endpoint of CVD, MI, stroke, revascularization, or rehospitalization for recurrent ischemia, but reduced the secondary composite endpoint of CVD, MI, or stroke (14.7% vorapaxar vs. 16.4% placebo; hazard ratio [HR], 0.89; 95% confidence interval [CI], 0.81 to 0.98; P=0.02; number needed to treat [NNT], 81). Recurrent secondary events occurred in 2.7% of patients. Vorapaxar reduced overall occurrences of ischemic events, first and subsequent (HR, 0.88; 95% CI, 0.80 to 0.98; P=0.02; NNT, 51). Also, there was a trend indicating that vorapaxar reduced the expanded endpoint, including revascularization and rehospitalization for recurrent ischemia (HR, 0.92; 95% CI, 0.84 to 1.01; P=0.09). Vorapaxar increased overall occurrences of moderate and severe Global Use of Strategies to Open Occluded Coronary Arteries bleeding (HR, 1.42; 95% CI, 1.21 to 1.66; PP\u3c0.001).
CONCLUSIONS: Vorapaxar reduced overall occurrences of ischemic events, but increased bleeding. These exploratory findings broaden our understanding of vorapaxar\u27s potential and expand our understanding of the value of capturing recurrent events
Ensemble evaluation of hydrological model hypotheses
It is demonstrated for the first time how model parameter, structural and data uncertainties can be accounted for explicitly and simultaneously within the Generalized Likelihood Uncertainty Estimation (GLUE) methodology. As an example application, 72 variants of a single soil moisture accounting store are tested as simplified hypotheses of runoff generation at six experimental grassland field-scale lysimeters through model rejection and a novel diagnostic scheme. The fields, designed as replicates, exhibit different hydrological behaviors which yield different model performances. For fields with low initial discharge levels at the beginning of events, the conceptual stores considered reach their limit of applicability. Conversely, one of the fields yielding more discharge than the others, but having larger data gaps, allows for greater flexibility in the choice of model structures. As a model learning exercise, the study points to a “leaking” of the fields not evident from previous field experiments. It is discussed how understanding observational uncertainties and incorporating these into model diagnostics can help appreciate the scale of model structural error
GREAT3 results I: systematic errors in shear estimation and the impact of real galaxy morphology
We present first results from the third GRavitational lEnsing Accuracy
Testing (GREAT3) challenge, the third in a sequence of challenges for testing
methods of inferring weak gravitational lensing shear distortions from
simulated galaxy images. GREAT3 was divided into experiments to test three
specific questions, and included simulated space- and ground-based data with
constant or cosmologically-varying shear fields. The simplest (control)
experiment included parametric galaxies with a realistic distribution of
signal-to-noise, size, and ellipticity, and a complex point spread function
(PSF). The other experiments tested the additional impact of realistic galaxy
morphology, multiple exposure imaging, and the uncertainty about a
spatially-varying PSF; the last two questions will be explored in Paper II. The
24 participating teams competed to estimate lensing shears to within systematic
error tolerances for upcoming Stage-IV dark energy surveys, making 1525
submissions overall. GREAT3 saw considerable variety and innovation in the
types of methods applied. Several teams now meet or exceed the targets in many
of the tests conducted (to within the statistical errors). We conclude that the
presence of realistic galaxy morphology in simulations changes shear
calibration biases by per cent for a wide range of methods. Other
effects such as truncation biases due to finite galaxy postage stamps, and the
impact of galaxy type as measured by the S\'{e}rsic index, are quantified for
the first time. Our results generalize previous studies regarding sensitivities
to galaxy size and signal-to-noise, and to PSF properties such as seeing and
defocus. Almost all methods' results support the simple model in which additive
shear biases depend linearly on PSF ellipticity.Comment: 32 pages + 15 pages of technical appendices; 28 figures; submitted to
MNRAS; latest version has minor updates in presentation of 4 figures, no
changes in content or conclusion
Analysis of the modes of energy consumption of the complex of an incoherent scattering of the institute of ionosphere of national academy of sciences and the ministry of education and science of Ukraine
У даній статті представлені результати аналізу режимів енергоспоживання комплексу некогерентного розсіяння Інституту іоносфери НАН і МОН України з метою вирішення проблеми підвищення енергоефективності науково-дослідного комплексу та створення енергоефективної системи електропостачання, яка забезпечить стійку роботу наукового обладнання для виконання дослідницьких програм НАН України. Описана система електроживлення комплексу та режими енергоспоживання комплексу. Описано пристрої радарної системи, а також найбільш потужні споживачі електроенергії, які споживають електроенергію на експериментальні і господарські потреби. Проаналізовано енергоспоживання комплексу некогерентного розсіяння за 2013 р. Отримано і представлено графіки середньої споживаної потужності (середньодобовий показник) і середньої споживаної потужності в режимі вимірювань. Описана доцільність проведення робіт з оптимізації енергопостачання науково-дослідного комплексу Інституту іоносфери. Запропоновано можливі заходи для зниження економічної вартості проведення експериментів з дослідження іоносфери науково-дослідного комплексу некогерентного розсіяння. Проведено аналіз робіт сучасних авторів з метою показати, що підвищення ефективності функціонування систем електропостачання є актуальною проблемою сучасних досліджень.This article presents the results of the analysis of the energy consumption modes of the incoherent scattering complex of the Institute of Ionosphere of the National Academy of Sciences and the Ministry of Education and Science of Ukraine to solve the problem of increasing the energy efficiency of a research complex and creating an energy efficient power supply system that will ensure the sustainability of scientific equipment for research programs
of the National Academy of Sciences of Ukraine. The system of power supply of the complex and modes of power consumption of the complex are described. The devices of the radar system are described, as well as the most powerful consumers of electricity, which consume electricity for experimental and economic needs. The energy consumption of the incoherent scattering complex in 2013 is analyzed. Graphs of the average power consumption (daily average) and average power consumption in measurement modes were obtained and presented. The feasibility of work to optimize the energy supply of the research complex of the institute of the ionosphere is described. Possible measures are proposed to reduce the economic cost of conducting experiments on the study of the ionosphere of an incoherent scattering research complex. The analysis of the works of modern authors i s
carried out in order to show that increasing the efficiency of the power supply systems is an actual problem of modern research
From segment to somite: segmentation to epithelialization analyzed within quantitative frameworks
One of the most visually striking patterns in the early developing embryo is somite segmentation. Somites form as repeated, periodic structures in pairs along nearly the entire caudal vertebrate axis. The morphological process involves short- and long-range signals that drive cell rearrangements and cell shaping to create discrete, epithelialized segments. Key to developing novel strategies to prevent somite birth defects that involve axial bone and skeletal muscle development is understanding how the molecular choreography is coordinated across multiple spatial scales and in a repeating temporal manner. Mathematical models have emerged as useful tools to integrate spatiotemporal data and simulate model mechanisms to provide unique insights into somite pattern formation. In this short review, we present two quantitative frameworks that address the morphogenesis from segment to somite and discuss recent data of segmentation and epithelialization
iSAW: Integrating Structure, Actors, and Water to Study Socio-Hydro-Ecological Systems
Urbanization, climate, and ecosystem change represent major challenges for managing water resources. Although water systems are complex, a need exists for a generalized representation of these systems to identify important components and linkages to guide scientific inquiry and aid water management. We developed an integrated Structure-Actor-Water framework (iSAW) to facilitate the understanding of and transitions to sustainable water systems. Our goal was to produce an interdisciplinary framework for water resources research that could address management challenges across scales (e.g., plot to region) and domains (e.g., water supply and quality, transitioning, and urban landscapes). The framework was designed to be generalizable across all human–environment systems, yet with sufficient detail and flexibility to be customized to specific cases. iSAW includes three major components: structure (natural, built, and social), actors (individual and organizational), and water (quality and quantity). Key linkages among these components include: (1) ecological/hydrologic processes, (2) ecosystem/geomorphic feedbacks, (3) planning, design, and policy, (4) perceptions, information, and experience, (5) resource access and risk, and (6) operational water use and management. We illustrate the flexibility and utility of the iSAW framework by applying it to two research and management problems: understanding urban water supply and demand in a changing climate and expanding use of green storm water infrastructure in a semi-arid environment. The applications demonstrate that a generalized conceptual model can identify important components and linkages in complex and diverse water systems and facilitate communication about those systems among researchers from diverse disciplines
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