3,030 research outputs found

    When Success Breeds Failure: History, Hysteresis, and Delayed Exit Decisions

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    The effects of feedback equivocality, information availability, and prior decision-making history on escalation and persistence were investigated. Replicating the findings of J.L. Bragger, D.H. Bragger, D.A. Hantula, and J.P. Kirnan (1998), this study found that participants receiving equivocal feedback on their decisions invested more money and invested across more opportunities; those who could purchase information invested fewer resources than did participants who did not have the opportunity to purchase information. There was an inverse linear relationship between the percentage of opportunities in which participants purchased information and the delay to exit decisions and total resources invested. Six weeks earlier, some participants took part in a more profitable investment scenario, and prior experience led to later increased investing when participants were faced with failure, even above that invested in a preceding, succeeding scenario. These results are consistent with an equivocality theory account of escalation

    Northern Long-eared Bat, Myotis septentrionalis (Chiroptera: Vespertilionidae), on Prince Edward Island: First Records of Occurrence and Over-Wintering

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    First occurrence of the Northern Long-eared Bat, Myotis septentrionalis, on Prince Edward Island is reported. A mixed-species hibernaculum of M. septentrionalis and the Little Brown Bat, M. lucifugus, is also described from southeastern Prince Edward Island. This is the first record of bats over-wintering in the province and the first time either species has been reported making use of a building as a hibernaculum

    How Postpartum Women with Depressive Symptoms Manage Sleep Disruption and Fatigue

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    Postpartum sleep and fatigue have bidirectional relationships with depressive symptoms and challenge women\u27s everyday functioning. The everyday process of managing postpartum sleep and fatigue in the context of depressive symptoms remains unexplored. We conducted a grounded theory study with a sample of 19 women who screened positive on the Postpartum Depression Screening Scale (PDSSℱ) Short Form at 3 weeks postpartum. Women completed semi‐structured in‐home interviews and the full PDSS and Modified Fatigue Symptoms Checklist at 1, 3, and 6 months postpartum. The sample was on average 27 years old, with 2.8 children, and 63% were African‐American. They described a basic social process of Finding a Routine Together, during which women\u27s experiences with their infants progressed from Retreating at month 1 toward Finding a New Normal at month 6. In their work to Find a Routine Together, mothers’ patterns of change over time were continuous, gradual, or prolonged. Their progress was influenced by depressive symptoms, social support, work and daycare, stability in social circumstances, and underlying stressors. This study\u27s findings suggest the need to allocate resources and tailor interventions to meet the needs of women who are most vulnerable to the health effects of ongoing persistent severe fatigue, disordered sleep, and sub‐clinical and clinical levels of depressive symptoms

    Quantifying engineered nanomaterial toxicity: comparison of common cytotoxicity and gene expression measurements

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    BACKGROUND: When evaluating the toxicity of engineered nanomaterials (ENMS) it is important to use multiple bioassays based on different mechanisms of action. In this regard we evaluated the use of gene expression and common cytotoxicity measurements using as test materials, two selected nanoparticles with known differences in toxicity, 5 nm mercaptoundecanoic acid (MUA)-capped InP and CdSe quantum dots (QDs). We tested the effects of these QDs at concentrations ranging from 0.5 to 160 ”g/mL on cultured normal human bronchial epithelial (NHBE) cells using four common cytotoxicity assays: the dichlorofluorescein assay for reactive oxygen species (ROS), the lactate dehydrogenase assay for membrane viability (LDH), the mitochondrial dehydrogenase assay for mitochondrial function, and the Comet assay for DNA strand breaks. RESULTS: The cytotoxicity assays showed similar trends when exposed to nanoparticles for 24 h at 80 ”g/mL with a threefold increase in ROS with exposure to CdSe QDs compared to an insignificant change in ROS levels after exposure to InP QDs, a twofold increase in the LDH necrosis assay in NHBE cells with exposure to CdSe QDs compared to a 50% decrease for InP QDs, a 60% decrease in the mitochondrial function assay upon exposure to CdSe QDs compared to a minimal increase in the case of InP and significant DNA strand breaks after exposure to CdSe QDs compared to no significant DNA strand breaks with InP. High-throughput quantitative real-time polymerase chain reaction (qRT-PCR) data for cells exposed for 6 h at a concentration of 80 ”g/mL were consistent with the cytotoxicity assays showing major differences in DNA damage, DNA repair and mitochondrial function gene regulatory responses to the CdSe and InP QDs. The BRCA2, CYP1A1, CYP1B1, CDK1, SFN and VEGFA genes were observed to be upregulated specifically from increased CdSe exposure and suggests their possible utility as biomarkers for toxicity. CONCLUSIONS: This study can serve as a model for comparing traditional cytotoxicity assays and gene expression measurements and to determine candidate biomarkers for assessing the biocompatibility of ENMs.1R01GM84702-01 - National Institute of General Medical Science

    Signal transduction and activator of transcription-3 (STAT3) in patients with colorectal cancer: associations with the phenotypic features of the tumour and host

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    Purpose: In patients with colorectal cancer (CRC), a high-density local inflammatory infiltrate response is associated with improved survival, whereas elevated systemic inflammatory responses are associated with poor survival. One potential unifying mechanism is the IL-6/JAK/STAT3 pathway. The present study examines the relationship between tumour total STAT3 and phosphorylated STAT3Tyr705 (pSTAT3) expression, host inflammatory responses and survival in patients undergoing resection of stage I-III CRC. Experimental Design: Immunohistochemical assessment of STAT3/pSTAT3 expression was performed using a tissue microarray and tumour cell expression divided into tertiles using the weighted histoscore. The relationship between STAT3/pSTAT3 expression and local inflammatory (CD3+, CD8+, CD45R0+, FOXP3+ T-cell density and Klintrup-MĂ€kinen grade) and systemic inflammatory responses and cancer-specific survival were examined. Results: 196 patients were included in the analysis. Cytoplasmic and nuclear STAT3 expression strongly correlated (r=0.363, P<0.001); nuclear STAT3 and pSTAT3 expression weakly correlated (r=0.130, P=0.068). Cytoplasmic STAT3 was inversely associated with the density of CD3+ (P=0.012), CD8+ (P=0.003) and FOXP3+ T-lymphocytes (P=0.002) within the cancer cell nests and was associated with an elevated systemic inflammatory response as measured by modified Glasgow Prognostic Score (mGPS2: 19% vs. 4%, P=0.004). The combination of nuclear STAT3/pSTAT3 stratified five-year survival from 81% to 62% (P=0.012), however was not associated with survival independent of venous invasion, tumour perforation or tumour budding. Conclusion In patients undergoing CRC resection, STAT3 expression was associated with adverse host inflammatory responses and reduced survival. Up-regulation of tumour STAT3 may be an important mechanism whereby the tumour deregulates local and systemic inflammatory responses

    Predispositions and the Political Behavior of American Economic Elites: Evidence from Technology Entrepreneurs

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    Economic elites regularly seek to exert political influence. But what policies do they support? Many accounts implicitly assume economic elites are homogeneous and that increases in their political power will increase inequality. We shed new light on heterogeneity in economic elites' political preferences, arguing that economic elites from an industry can share distinctive preferences due in part to sharing distinctive predispositions. Consequently, how increases in economic elites' influence affect inequality depends on which industry's elites are gaining influence and which policy issues are at stake. We demonstrate our argument with four original surveys, including the two largest political surveys of American economic elites to date: one of technology entrepreneurs—whose influence is burgeoning—and another of campaign donors. We show that technology entrepreneurs support liberal redistributive, social, and globalistic policies but conservative regulatory policies—a bundle of preferences rare among other economic elites. These differences appear to arise partly from their distinctive predispositions

    Metallicity Mapping with gri Photometry: The Virgo Overdensity and the Halos of the Galaxy

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    We describe the methodology required for estimation of photometric estimates of metallicity based on the SDSS gri passbands, which can be used to probe the properties of main-sequence stars beyond ~ 10 kpc, complementing studies of nearby stars from more metallicity-sensitive color indices that involve the u passband. As a first application of this approach, we determine photometric metal abundance estimates for individual main-sequence stars in the Virgo Overdensity, which covers almost 1000 square degrees on the sky, based on a calibration of the metallicity sensitivity of stellar isochrones in the gri filter passbands using field stars with well-determined spectroscopic metal abundances. Despite the low precision of the method for individual stars, internal errors of in [Fe/H] ~ +/- 0.1 dex can be achieved for bulk stellar populations. The global metal abundance of the Virgo Overdensity determined in this way is = -2.0 +/- 0.1 (internal) +/- 0.5 (systematic), from photometric measurements of 0.7 million stars with heliocentric distances from ~ 10 kpc to ~ 20 kpc. A preliminary metallicity map, based on results for 2.9 million stars in the northern SDSS DR-7 footprint, exhibits a shift to lower metallicities as one proceeds from the inner- to the outer-halo population, consistent with recent interpretation of the kinematics of local samples of stars with spectroscopically available metallicity estimates and full space motions.Comment: 4 pages, 2 figures, to appear in IAU Symp. 26

    Perceived clinician-patient communication in the emergency department and subsequent post-traumatic stress symptoms in patients evaluated for acute coronary syndrome

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    Objectives: Evaluation for a potentially life-threatening cardiac event in the emergency department (ED) is a stressful experience that can result in symptoms of post-traumatic stress disorder, which are associated with increased risk of morbidity and mortality in patients. No study has tested whether good clinician–patient communication in the ED is associated with better psychological outcomes in these individuals and whether it can mitigate other risk factors for post-traumatic stress symptoms (PSS) such as perception of life threat and vulnerability in the ED. Methods: Data were analysed from 474 participants in the Reactions to Acute Care and Hospitalization (REACH) study, an observational cohort study of ED predictors of medical and psychological outcomes after evaluation for suspected acute coronary syndrome. Participants were recruited from November 2013 to January 2015 at a single-site academic medical centre (New York-Presbyterian-Columbia University Medical Center). Participants reported threat perceptions in the ED and provided information on their perceptions of clinician–patient communication using the Interpersonal Process of Care Survey. PSS were assessed using the Acute Stress Disorder Scale during follow-up. Results: 474 subjects were enrolled in the study. Median length of follow-up was 3 days after ED presentation, range 0–30 days, 80% within 8 days. Perceptions of good clinician–patient communication in the ED were associated with lower PSS, whereas increased threat perception was associated with higher PSS. A significant interaction between clinician–patient communication and threat perception on PSS suggested that patients with higher threat perception benefited most from good clinician–patient communication. Conclusion: Our study found an association between good clinician–patient communication in the ED during evaluation of potentially life-threatening cardiac events and decreased subsequent post-traumatic stress reactions. This association is particularly marked for patients who perceive the greatest degree of life threat and vulnerability during evaluation
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