954 research outputs found
Looking Beyond Looks: Comments on Sloutsky, Kloos, and Fisher (2007)
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75080/1/j.1467-9280.2007.01937.x.pd
Traveling length and minimal traveling time for flow through percolation networks with long-range spatial correlations
We study the distributions of traveling length l and minimal traveling time t
through two-dimensional percolation porous media characterized by long-range
spatial correlations. We model the dynamics of fluid displacement by the
convective movement of tracer particles driven by a pressure difference between
two fixed sites (''wells'') separated by Euclidean distance r. For strongly
correlated pore networks at criticality, we find that the probability
distribution functions P(l) and P(t) follow the same scaling Ansatz originally
proposed for the uncorrelated case, but with quite different scaling exponents.
We relate these changes in dynamical behavior to the main morphological
difference between correlated and uncorrelated clusters, namely, the
compactness of their backbones. Our simulations reveal that the dynamical
scaling exponents for correlated geometries take values intermediate between
the uncorrelated and homogeneous limiting cases
Recommended from our members
High temperature deformation in 2036 Al and 0.2 wt % Zr-2036 A1
The microstructure and high-temperature deformation of 2036 Al and a 0.2 wt % Zr modified 2036 Al were characterized. A particle-simulated- nucleation process was applied to refine grain structure in both alloys. Thermomechanically processed materials were tested from 450 to 500 C and strain rates from 2{times}10{sup {minus}1} to 2{times}10{sup {minus}4}s{sup {minus}1}. Strain rate sensitivity exponent, activation energy, and total elongation were measured, and the deformation mechanism was proposed. Effect of Zr on microstructure and deformation of 2036 Al at elevated temperatures was discussed
Equilibration processes in the Warm-Hot Intergalactic Medium
The Warm-Hot Intergalactic Medium (WHIM) is thought to contribute about 40-50
% to the baryonic budget at the present evolution stage of the universe. The
observed large scale structure is likely to be due to gravitational growth of
density fluctuations in the post-inflation era. The evolving cosmic web is
governed by non-linear gravitational growth of the initially weak density
fluctuations in the dark energy dominated cosmology. Non-linear structure
formation, accretion and merging processes, star forming and AGN activity
produce gas shocks in the WHIM. Shock waves are converting a fraction of the
gravitation power to thermal and non-thermal emission of baryonic/leptonic
matter. They provide the most likely way to power the luminous matter in the
WHIM. The plasma shocks in the WHIM are expected to be collisionless.
Collisionless shocks produce a highly non-equilibrium state with anisotropic
temperatures and a large differences in ion and electron temperatures. We
discuss the ion and electron heating by the collisionless shocks and then
review the plasma processes responsible for the Coulomb equilibration and
collisional ionisation equilibrium of oxygen ions in the WHIM. MHD-turbulence
produced by the strong collisionless shocks could provide a sizeable
non-thermal contribution to the observed Doppler parameter of the UV line
spectra of the WHIM.Comment: 13 pages, 4 figures, accepted for publication in Space Science
Reviews, special issue "Clusters of galaxies: beyond the thermal view",
Editor J.S. Kaastra, Chapter 8; work done by an international team at the
International Space Science Institute (ISSI), Bern, organised by J.S.
Kaastra, A.M. Bykov, S. Schindler & J.A.M. Bleeke
Revisiting the X:BOT Naltrexone Clinical Trial Using a Comprehensive Survival Analysis
Objectives This paper illustrates survival models for analysis of trials of substance use treatment programs. It uses public release data from a study of extended-release naltrexone (XR-NTX), relative to buprenorphine-naloxone (BUP-NX). Methods We used publicly available data from the X:BOT trial (n = 570), which compared XR-NTX to BUP-NX on 2 efficacy outcomes (opioid relapse, use of nonprescribed opioids; positive opioid urine test) and 1 safety outcome (overdose). Intention-to-treat (ITT) and per-protocol approaches were implemented using survival models that included treatment-by-time interactions. Results Consistent with the original trial findings, 72% of XR-NTX and 94% of BUP-NX subjects initiated treatment; the ITT hazard ratio for XR-NTX relative to BUP-NX was 1.40 (95% confidence interval: 1.13, 1.73; P < 0.01) for opioid relapse and 1.31 (1.07, 1.60; P = 0.01) for positive urine test. Using treatment-by-time interactions, we examined the time-dependent effect of XR-NTX and found an elevated ITT overdose hazard ratio of 2.4 (1.1, 5.3; P = 0.03) overall and 3.8 (1.2, 11.6; P = 0.02) during the study treatment phase. This result (28 overdoses overall; 17 overdoses during the study treatment phase) contrasts with the previous analysis, which reported minimal differences in overdose between XR-NTX and BUP-NX. Conclusions An advantage of using time-dependent Cox models is its ability to isolate effects during specific periods. In general, our survival analyses concur with the conclusions of Lee et al (2018) for the efficacy outcomes, which demonstrated superiority of BUP-NX. In contrast to the original report, our analysis indicates a greater risk of overdose for XR-NTX, predominantly during the study treatment phase. Further investigation of this finding is a pressing research priority
Rumo a uma sociedade melhor: uma análise da agenda de reformas econômicas de J. S. Mill
Women, men and coronary heart disease: a review of the qualitative literature
Aim. This paper presents a review of the qualitative literature which examines the experiences of patients with coronary heart disease. The paper also assesses whether the experiences of both female and male patients are reflected in the literature and summarizes key themes.
Background. Understanding patients' experiences of their illness is important for coronary heart disease prevention and education. Qualitative methods are particularly suited to eliciting patients' detailed understandings and perceptions of illness. As much previous research has been 'gender neutral', this review pays particular attention to gender.
Methods. Published papers from 60 qualitative studies were identified for the review through searches in MEDLINE, EMBASE, CINAHL, PREMEDLINE, PsychINFO, Social Sciences Citation Index and Web of Science using keywords related to coronary heart disease.
Findings. Early qualitative studies of patients with coronary heart disease were conducted almost exclusively with men, and tended to generalize from 'male' experience to 'human' experience. By the late 1990s this pattern had changed, with the majority of studies including women and many being conducted with solely female samples. However, many studies that include both male and female coronary heart disease patients still do not have a specific gender focus. Key themes in the literature include interpreting symptoms and seeking help, belief about coronary 'candidates' and relationships with health professionals. The influence of social roles is important: many female patients have difficulties reconciling family responsibilities and medical advice, while male patients worry about being absent from work.
Conclusions. There is a need for studies that compare the experiences of men and women. There is also an urgent need for work that takes masculinity and gender roles into account when exploring the experiences of men with coronary heart disease
Multimessenger astronomy with the Einstein Telescope
Gravitational waves (GWs) are expected to play a crucial role in the
development of multimessenger astrophysics. The combination of GW observations
with other astrophysical triggers, such as from gamma-ray and X-ray satellites,
optical/radio telescopes, and neutrino detectors allows us to decipher science
that would otherwise be inaccessible. In this paper, we provide a broad review
from the multimessenger perspective of the science reach offered by the third
generation interferometric GW detectors and by the Einstein Telescope (ET) in
particular. We focus on cosmic transients, and base our estimates on the
results obtained by ET's predecessors GEO, LIGO, and Virgo.Comment: 26 pages. 3 figures. Special issue of GRG on the Einstein Telescope.
Minor corrections include
Making things happen : a model of proactive motivation
Being proactive is about making things happen, anticipating and preventing problems, and seizing opportunities. It involves self-initiated efforts to bring about change in the work environment and/or oneself to achieve a different future. The authors develop existing perspectives on this topic by identifying proactivity as a goal-driven process involving both the setting of a proactive goal (proactive goal generation) and striving to achieve that proactive goal (proactive goal striving). The authors identify a range of proactive goals that individuals can pursue in organizations. These vary on two dimensions: the future they aim to bring about (achieving a better personal fit within one’s work environment, improving the organization’s internal functioning, or enhancing the organization’s strategic fit with its environment) and whether the self or situation is being changed. The authors then identify “can do,” “reason to,” and “energized to” motivational states that prompt proactive goal generation and sustain goal striving. Can do motivation arises from perceptions of self-efficacy, control, and (low) cost. Reason to motivation relates to why someone is proactive, including reasons flowing from intrinsic, integrated, and identified motivation. Energized to motivation refers to activated positive affective states that prompt proactive goal processes. The authors suggest more distal antecedents, including individual differences (e.g., personality, values, knowledge and ability) as well as contextual variations in leadership, work design, and interpersonal climate, that influence the proactive motivational states and thereby boost or inhibit proactive goal processes. Finally, the authors summarize priorities for future researc
A case-control study of peripheral blood mitochondrial DNA copy number and risk of renal cell carcinoma
ackground
Low mitochondrial DNA (mtDNA) copy number is a common feature of renal cell carcinoma (RCC), and may influence tumor development. Results from a recent case-control study suggest that low mtDNA copy number in peripheral blood may be a marker for increased RCC risk. In an attempt to replicate that finding, we measured mtDNA copy number in peripheral blood DNA from a U.S. population-based case-control study of RCC.
Methodology/Principal Findings
Relative mtDNA copy number was measured in triplicate by a quantitative real-time PCR assay using DNA extracted from peripheral whole blood. Cases (n = 603) had significantly lower mtDNA copy number than controls (n = 603; medians 0.85, 0.91 respectively; P = 0.0001). In multiple logistic regression analyses, the lowest quartile of mtDNA copy number was associated with a 60% increase in RCC risk relative to the highest quartile (OR = 1.6, 95% CI = 1.1\u20132.2; Ptrend = 0.009). This association remained in analyses restricted to cases treated by surgery alone (OR Q1 = 1.4, 95% CI = 1.0\u20132.1) and to localized tumors (2.0, 1.3\u20132.8).
Conclusions/Significance
Our findings from this investigation, to our knowledge the largest of its kind, offer important confirmatory evidence that low mtDNA copy number is associated with increased RCC risk. Additional research is needed to assess whether the association is replicable in prospective studies
- …