ABSTRACT Ground-based observatories have been collecting 0.2-20 TeV gamma-rays from blazars for about twenty years. These gamma-rays can experience absorption along the line of sight due to ...interactions with the extragalactic background light (EBL). In this paper, we show that the gamma-ray optical depth can be reduced to the convolution product of an EBL kernel with the EBL intensity, assuming a particular form for the EBL evolution. We extract the absorption signal from the most extensive set of TeV spectra from blazars collected so far and unveil a broadband EBL spectrum from mid-ultraviolet to far-infrared. This spectrum is in good agreement with the accumulated emission of galaxies, constraining unresolved populations of sources. We propose a data-driven estimate of the Hubble constant based on the comparison of local and gamma-ray measurements of the EBL. After setting stringent upper-limits on the redshift of four TeV blazars, we investigate the 106 gamma-ray spectra in our sample and find no significant evidence for anomalies. The intrinsic TeV spectra are not harder than their GeV counterpart, and no spectral upturn is visible at the highest optical depths. Finally, we investigate a modification of the pair-creation threshold due to Lorentz invariance violation. A mild excess prevents us from ruling out an effect at the Planck energy, and we constrain for the first time the energy scale of the modification to values larger than 60% of the Planck energy.
Various commonly used organic solvents were dried with several different drying agents. A glovebox-bound coulometric Karl Fischer apparatus with a two-compartment measuring cell was used to determine ...the efficiency of the drying process. Recommendations are made relating to optimum drying agents/conditions that can be used to rapidly and reliably generate solvents with low residual water content by means of commonly available materials found in most synthesis laboratories. The practical method provides for safer handling and drying of solvents than methods calling for the use of reactive metals, metal hydrides, or solvent distillation.
Ostracism Williams, Kipling D
Annual review of psychology,
2007, Letnik:
58
Journal Article
Recenzirano
In this review, I examine the social psychological research on ostracism, social exclusion, and rejection. Being ignored, excluded, and/or rejected signals a threat for which reflexive detection in ...the form of pain and distress is adaptive for survival. Brief ostracism episodes result in sadness and anger and threaten fundamental needs. Individuals then act to fortify or replenish their thwarted need or needs. Behavioral consequences appear to be split into two general categories: attempts to fortify relational needs (belonging, self-esteem, shared understanding, and trust), which lead generally to prosocial thoughts and behaviors, or attempts to fortify efficacy/existence needs of control and recognition that may be dealt with most efficiently through antisocial thoughts and behaviors. Available research on chronic exposure to ostracism appears to deplete coping resources, resulting in depression and helplessness.
Experimental evidence accumulated over decades has implicated epithelial-mesenchymal plasticity (EMP), which collectively encompasses epithelial-mesenchymal transition and the reverse process of ...mesenchymal-epithelial transition, in tumour metastasis, cancer stem cell generation and maintenance, and therapeutic resistance. However, the dynamic nature of EMP processes, the apparent need to reverse mesenchymal changes for the development of macrometastases and the likelihood that only minor cancer cell subpopulations exhibit EMP at any one time have made such evidence difficult to accrue in the clinical setting. In this Perspectives article, we outline the existing preclinical and clinical evidence for EMP and reflect on recent controversies, including the failure of initial lineage-tracing experiments to confirm a major role for EMP in dissemination, and discuss accumulating data suggesting that epithelial features and/or a hybrid epithelial-mesenchymal phenotype are important in metastasis. We also highlight strategies to address the complexities of therapeutically targeting the EMP process that give consideration to its spatially and temporally divergent roles in metastasis, with the view that this will yield a potent and broad class of therapeutic agents.
PURPOSEHigh school cross-country runners have a high incidence of injury, particularly at the shin and knee. An increased step rate during running has been shown to reduce impact forces and loading ...of the lower extremity joints. The purpose of this prospective study was to examine step rate as a risk factor for injury occurrence.
MATERIALS AND METHODSRunning step rates of 68 healthy high school cross-country runners (47 females; 21 males; mean age 16.2 ± 1.3 yr) were assessed at a fixed speed (3.3 ± 0.0 m·s) and self-selected speed (mean, 3.8 ± 0.5 m·s). Runners were prospectively followed during the interscholastic season to determine athletic exposures, occurrences of shin injury and anterior knee pain (AKP), and days lost to injury.
RESULTSDuring the season, 19.1% of runners experienced a shin injury and 4.4% experienced AKP. Most injuries (63.6%) were classified as minor (1–7 d lost). At the fixed speed, runners in the lowest tertile of step rate (≤164 steps per minute) were more likely (odds ratio, 6.67; 95% confidence interval, 1.2–36.7; P = 0.03) to experience a shin injury compared with runners in the highest tertile (≥174 steps per minute). Similarly, for self-selected speed, runners in the lowest tertile (≤166 steps per minute) (odds ratio, 5.85; 95% confidence interval, 1.1–32.1; P < 0.04) were more likely to experience a shin injury than runners in the highest tertile (≥178 steps per minute). AKP incidence was not significantly influenced by step rate.
CONCLUSIONA lower running step rate was associated with a greater likelihood of shin injury at both self-selected and fixed running speeds. Future studies evaluating whether increasing running step rate reduces shin injury risk and time lost during a high school cross-country season should be considered.
The range of benefits associated with regular physical activity participation is irrefutable. Despite the well-known benefits, physical inactivity remains one of the major contributing factors to ...ill-health throughout industrialized countries. Traditional lifestyle interventions such as group education or telephone counseling are effective at increasing physical activity participation; however, physical activity levels tend to decline over time. Consumer-based wearable activity trackers that allow users to objectively monitor activity levels are now widely available and may offer an alternative method for assisting individuals to remain physically active.
This review aimed to determine the effects of interventions utilizing consumer-based wearable activity trackers on physical activity participation and sedentary behavior when compared with interventions that do not utilize activity tracker feedback.
A systematic review was performed searching the following databases for studies that included the use of a consumer-based wearable activity tracker to improve physical activity participation: Cochrane Controlled Register of Trials, MEDLINE, PubMed, Scopus, Web of Science, Cumulative Index of Nursing and Allied Health Literature, SPORTDiscus, and Health Technology Assessments. Controlled trials of adults comparing the use of a consumer-based wearable activity tracker with other nonactivity tracker-based interventions were included. The main outcome measures were physical activity participation and sedentary behavior. All studies were assessed for risk of bias, and the Grades of Recommendation, Assessment, Development, and Evaluation system was used to rank the quality of evidence. The guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement were followed. A random-effects meta-analysis was completed on the included outcome measures to estimate the treatment effect of interventions that included an activity tracker compared with a control group.
There was a significant increase in daily step count (standardized mean difference SMD 0.24; 95% CI 0.16 to 0.33; P<.001), moderate and vigorous physical activity (SMD 0.27; 95% CI 0.15 to 0.39; P<.001), and energy expenditure (SMD 0.28; 95% CI 0.03 to 0.54; P=.03) and a nonsignificant decrease in sedentary behavior (SMD -0.20; 95% CI -0.43 to 0.03; P=.08) following the intervention versus control comparator across all studies in the meta-analyses. In general, included studies were at low risk of bias, except for performance bias. Heterogeneity varied across the included meta-analyses ranging from low (I
=3%) for daily step count through to high (I
=67%) for sedentary behavior.
Utilizing a consumer-based wearable activity tracker as either the primary component of an intervention or as part of a broader physical activity intervention has the potential to increase physical activity participation. As the effects of physical activity interventions are often short term, the inclusion of a consumer-based wearable activity tracker may provide an effective tool to assist health professionals to provide ongoing monitoring and support.
The assessment of loading during walking and running has historically been limited to data collection in laboratory settings or with devices that require a computer connection. This study aims to ...determine if the loadsol
-a single sensor wireless insole-is a valid and reliable method of assessing force. Thirty (17 male and 13 female) recreationally active individuals were recruited for a two visit study where they walked (1.3 m/s) and ran (3.0 and 3.5 m/s) at a 0%, 10% incline, and 10% decline, with the visits approximately one week apart. Ground reaction force data was collected on an instrumented treadmill (1440 Hz) and with the loadsol
(100 Hz). Ten individuals completed the day 1 protocol with a newer 200 Hz loadsol
. Intraclass correlation coefficients (ICC3,k) were used to assess validity and reliability and Bland⁻Altman plots were generated to better understand loadsol
validity. Across conditions, the peak force ICCs ranged from 0.78 to 0.97, which increased to 0.84⁻0.99 with the 200 Hz insoles. Similarly, the loading rate ICCs improved from 0.61 to 0.97 to 0.80⁻0.96 and impulse improved from 0.61 to 0.97 to 0.90⁻0.97. The 200 Hz insoles may be needed for loading rate and impulse in running. For both walking and running, the loadsol
has excellent between-day reliability (>0.76).
This study empirically examines the role of shocks to macro-uncertainty in shaping the responses of stock market participants to firm-specific earnings news. Specifically, I find that investors place ...greater weight on bad news following an increase in macro-uncertainty. By contrast, I find that investors place equal weight on both good and bad news following a decrease in macro-uncertainty. Furthermore, my findings show that these effects are more pronounced (1) for firms whose prior returns are more correlated with macro-uncertainty, (2) for firms that experience abnormally low trading volume during the earnings announcement, (3) for firms with relatively lower levels of institutional ownership, and (4) for firms with relatively higher information uncertainty. In sum, these findings provide novel empirical evidence that investors behave in a manner consistent with ambiguity aversion, with the effects strongest among unsophisticated investors.
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