729 research outputs found

    YouTube, Social Norms and Perceived Salience of Climate Change in the American Mind

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    This online experiment explored how contextual information embedded in new media channels such as YouTube may serve as normative social cues to users. Specifically, we examined whether the number of views listed under a YouTube video about climate change would elicit inferences regarding how “others” feel about the climate issue and, consequently, might influence perceptions of issue salience. Participants in this experiment were exposed to a YouTube video about climate change using two experimental conditions, one providing a small number of views under the video and the second listing a large number of views. Results suggest that the “number of views” cue did, indeed, influence participant perceptions of the importance assigned by other Americans to the issue of climate change. Further, compared to low self-monitoring participants, high self-monitoring participants registered an increase in their own judgment of issue importance

    Forming Giant Planets Around Late-M Dwarfs: Pebble Accretion and Planet-Planet Collision

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    We propose a pebble-driven core accretion scenario to explain the formation of giant planets around the late-M dwarfs of $M_{\star}{=}0.1{-}0.2 \ M_{\odot}.Inordertoexploretheoptimaldiskconditionsforgiantplanet,weperformN−bodysimulationstoinvestigatethegrowthanddynamicalevolutionofbothsingleandmultipleprotoplanetsinthediskswithbothinnerviscouslyheatedandouterstellarirradiatedregions.Theinitialmassesoftheprotoplanetsareeitherassumedtobeequalto. In order to explore the optimal disk conditions for giant planet, we perform N-body simulations to investigate the growth and dynamical evolution of both single and multiple protoplanets in the disks with both inner viscously heated and outer stellar irradiated regions. The initial masses of the protoplanets are either assumed to be equal to 0.01 \ M_{\oplus}orcalculatedbasedontheformuladerivedfromstreaminginstabilitysimulations.Ourfindingsindicatethatmassiveplanetsaremorelikelytoformindiskswithlongerlifetimes,highersolidmasses,moderatetohighlevelsofdiskturbulence,andlargerinitialmassesofprotoplanets.Inthesingleprotoplanetgrowthcases,thehighestplanetcoremassthatcanbereachedisgenerallylowerthanthethresholdnecessarytotriggerrapidgasaccretion,whichimpedestheformationofgiantplanets.Nonetheless,inmulti−protoplanetcases,thecorescanexceedthepebbleisolationmassbarrieraidedbyfrequentplanet−planetcollisions.Thisconsequentlyspeedsuptheirgasaccretionandpromotesgiantplanetformation,makingtheoptimalparameterspacetogrowgiantplanetssubstantiallywider.Takentogether,ourresultssuggestthatevenaroundverylow−massstellarhosts,thegiantplanetswithorbitalperiodsof or calculated based on the formula derived from streaming instability simulations. Our findings indicate that massive planets are more likely to form in disks with longer lifetimes, higher solid masses, moderate to high levels of disk turbulence, and larger initial masses of protoplanets. In the single protoplanet growth cases, the highest planet core mass that can be reached is generally lower than the threshold necessary to trigger rapid gas accretion, which impedes the formation of giant planets. Nonetheless, in multi-protoplanet cases, the cores can exceed the pebble isolation mass barrier aided by frequent planet-planet collisions. This consequently speeds up their gas accretion and promotes giant planet formation, making the optimal parameter space to grow giant planets substantially wider. Taken together, our results suggest that even around very low-mass stellar hosts, the giant planets with orbital periods of {\lesssim}100daysarestilllikelytoformwhenlunar−massprotoplanetsfirstemergefromplanetesimalaccretionandthengrowrapidlybyacombinationofpebbleaccretionandplanet−planetcollisionsindiskswithahighsupplyofpebblereservoir days are still likely to form when lunar-mass protoplanets first emerge from planetesimal accretion and then grow rapidly by a combination of pebble accretion and planet-planet collisions in disks with a high supply of pebble reservoir {>}50 \ M_{\oplus}andturbulentlevelof and turbulent level of \alpha_{\rm t} {\sim} 10^{-3}{-}10^{-2}$.Comment: 22 pages, 13 figures, 3 tables, Accepted for publication in A&

    Crystal Growth of II-VI Semiconducting Alloys by Directional Solidification

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    This research study is investigating the effects of a microgravity environment during the crystal growth of selected II-VI semiconducting alloys on their compositional, metallurgical, electrical and optical properties. The on-going work includes both Bridgman-Stockbarger and solvent growth methods, as well as growth in a magnetic field. The materials investigated are II-VI, Hg(1-x)Zn(x)Te, and Hg(1-x)Zn(x)Se, where x is between 0 and 1 inclusive, with particular emphasis on x-values appropriate for infrared detection and imaging in the 5 to 30 micron wavelength region. Wide separation between the liquidus and solidus of the phase diagrams with consequent segregation during solidification and problems associated with the high volatility of one of the components (Hg), make the preparation of homogeneous, high-quality, bulk crystals of the alloys an extremely difficult nearly an impossible task in a gravitational environment. The three-fold objectives of the on-going investigation are as follows: (1) To determine the relative contributions of gravitationally-driven fluid flows to the compositional redistribution observed during the unidirectional crystal growth of selected semiconducting solid solution alloys having large separation between the liquidus and solidus of the constitutional phase diagram; (2) To ascertain the potential role of irregular fluid flows and hydrostatic pressure effects in generation of extended crystal defects and second-phase inclusions in the crystals; and, (3) To obtain a limited amount of "high quality" materials needed for bulk crystal property characterizations and for the fabrication of various device structures needed to establish ultimate material performance limits. The flight portion of the study was to be accomplished by performing growth experiments using the Crystal Growth Furnace (CGF) manifested to fly on various Spacelab missions

    Regional Differences in Rates of HIV-1 Viral Load Monitoring in Canada: Insights and Implications for Antiretroviral Care in High Income Countries

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    Background: Viral load (VL) monitoring is an essential component of the care of HIV positive individuals. Rates ofVL monitoring have been shown to vary by HIV risk factor and clinical characteristics. The objective of this studywas to determine whether there are differences among regions in Canada in the rates of VL testing of HIV-positiveindividuals on combination antiretroviral therapy (cART), where the testing is available without financial barriersunder the coverage of provincial health insurance programs.Methods: The Canadian Observational Cohort (CANOC) is a collaboration of nine Canadian cohorts of HIV-positiveindividuals who initiated cART after January 1, 2000. The study included participants with at least one year offollow-up. Generalized Estimating Equation (GEE) regression models were used to determine the effect ofgeographic region on (1) the occurrence of an interval of 9 months or more between two consecutive recordedVL tests and (2) the number of days between VL tests, after adjusting for demographic and clinical covariates.Overall and regional annual rates of VL testing were also reported.Results: 3,648 individuals were included in the analysis with a median follow-up of 42.9 months and a median of15 VL tests. In multivariable GEE logistic regression models, gaps in VL testing >9 months were more likely inQuebec (Odds Ratio (OR) = 1.72, p < 0.0001) and Ontario (OR = 1.78, p < 0.0001) than in British Columbia andamong injection drug users (OR = 1.68, p < 0.0001) and were less likely among older individuals (OR = 0.77 per10 years, p < 0.0001), among men having sex with men (OR = 0.62, p < 0.0001), within the first year of cART(OR = 0.15, p < 0.0001), among individuals on cART at the time of the blood draw (OR = 0.34, p < 0.0001) andamong individuals with VL < 50 copies/ml at the previous visit (OR = 0.56, p < .0001).Conclusions: Significant variation in rates of VL testing and the probability of a significant gap in testing wererelated to geographic region, HIV risk factor, age, year of cART initiation, type of cART regimen, being in the firstyear of cART, AIDS-defining illness and whether or not the previous VL was below the limit of detection

    UV Light‐Driven Nitric Oxide Release from Porous Nitrogen Heterocyclic Polymers

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    In this study, porous polymers with nitrogen heterocyclic core structures are synthesized through the condensation of enaminonitrile and terephthalaldehyde monomers. These polymers are used as a platform to store bioactive nitric oxide (NO) and control its release. NO loading is achieved by nitrosating the polymers with acidified nitrite, a process that also imparts photoresponsivity to the polymers. Polymer composition and porosity affect NO storage and release. It is observed that under UV light at 365 nm in a PBS solution, the polymers (NO@DHP-POP) can release NO in a manner fully controlled by UV lighting. Under experimental conditions, these porous polymers release NO at a rate of ≈10.0–50.0 ”mol g −1 over 60 min. These findings demonstrate the potential of these polymers for integrating NO delivery into phototherapy applications

    Emotion Regulation in the Prisoner’s Dilemma: Effects of Reappraisal on Behavioral Measures and Cardiovascular Measures of Challenge and Threat

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    The current study examines cooperation and cardiovascular responses in individuals that were defected on by their opponent in the first round of an iterated Prisoner’s Dilemma. In this scenario, participants were either primed with the emotion regulation strategy of reappraisal or no emotion regulation strategy, and their opponent either expressed an amused smile or a polite smile after the results were presented. We found that cooperation behavior decreased in the no emotion regulation group when the opponent expressed an amused smile compared to a polite smile. In the cardiovascular measures, we found significant differences between the emotion regulation conditions using the biopsychosocial (BPS) model of challenge and threat. However, the cardiovascular measures of participants instructed with the reappraisal strategy were only weakly comparable with a threat state of the BPS model, which involves decreased blood flow and perception of greater task demands than resources to cope with those demands. Conversely, the cardiovascular measures of participants without an emotion regulation were only weakly comparable with a challenge state of the BPS model, which involves increased blood flow and perception of having enough or more resources to cope with task demands

    A phase 1, open-label, dose-escalation trial of oral TSR-011 in patients with advanced solid tumours and lymphomas

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    Anaplastic lymphoma kinase (ALK) gene rearrangements are oncogenic drivers in non-small-cell lung cancer (NSCLC). TSR-011 is a dual ALK and tropomyosin-related kinase (TRK) inhibitor, active against ALK inhibitor resistant tumours in preclinical studies. Here, we report the safety, tolerability and recommended phase 2 dose (RP2D) of TSR-011 in patients with relapsed or refractory ALK- and TRK-positive advanced cancers. Methods: In this sequential, open-label, phase 1 trial (NCT02048488), patients received doses of 30 mg, escalated to 480 mg every 24 hours (Q24h), followed by an expansion cohort of patients with ALK-positive cancers. The primary objective was to evaluate safety and tolerability. Secondary objectives included pharmacokinetics. Results: TSR-011 320- and 480-mg Q24h doses exceeded the maximum tolerated dose. At the RP2D of 40 mg every 8 hours (Q8h), the most common grade 3–4 treatment-emergent adverse events occurred in 3.2–6.5% of patients. Of 14 ALK inhibitor-naive patients with ALK-positive NSCLC, 6 experienced partial responses and 8 had stable disease. Conclusions: At the RP2D (40 mg Q8h), TSR-011 demonstrated a favourable safety profile with acceptable QTc changes. Limited clinical activity was observed. Based on the competitive ALK inhibitor landscape and benefit/risk considerations, further TSR-011 development was discontinuedThis clinical trial was funded by TESAR

    The effects of occupational stress on the management of an organization

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    Occupational stress is an important issue not only for the researchers but also for the employees and managers at work. This study aims to determine the effects of occupational stress on job satisfaction, intention to leave and absenteeism. A sample of 100 employees in the Companies Commission of Malaysia, a statutory body regulating companies and businesses was recruited to participate in the study. A questionnaire was used to collect information on demographics, stress, job satisfaction, intention to leave and absenteeism. Pearson correlation and Multiple Linear Regression was used to examine the relationships between different variables. The results show that occupational stress does not have a direct effect on the intention to leave and absenteeism. In contrast, occupational stress has a direct negative effect on job satisfaction. Furthermore, job satisfaction has negative effects on the intention to leave and absenteeism. In conclusion, the authors recommend the following to management: (a) increasing job satisfaction by reducing employee occupational stress, and (b) that by reducing stress, the organization can reduce the levels of intention to leave and absenteeism among employee
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