571 research outputs found

    Large particle characteristics over the southern ocean during ACE 1

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    December 1998.Also issued as Janel T. Davis's thesis (M.S.) -- Colorado State University, 1998.Includes bibliographical references.The Aerosol Characterization Experiment (ACE-1) in November and December 1995 was designed to characterize aerosol physical, chemical, and optical properties in remote marine regions in the Southern Hemisphere. Data from six ACE-1 research flights were used to examine concentrations of large particles in two size ranges: those having diameters, Dp, 0.5 Dp 50 ”m (N1) and those with 2.0 Dp 50 ”m (N2). Reported here are observations of vertical profiles of N1 and N2 for heights, z, from ~30 to 7000 mover the ocean surface. Number concentrations near the surface (z 900 m) varied from 0.8 to ~30 cm-3, while maximum N2 concentrations were ~ 2.0 cm-3. Above altitudes of 2400 m, N1 concentrations were found to vary from greater than 0.07 to 1.2 cm-3. Significant concentrations (> 0.02 cm-3) of N2 particles aloft were usually associated with regions of deep convection, cloud outflow, and cloud dissipation. Calculated dry mass concentrations for N1 particles near the surface (z 100 m) assumed to be primarily sea salt, showed dependence on wind speed. Computed dry sea salt mass concentrations varied from 2.0 to 30.0 ”g m-3 and varied with wind speed similarly to previously proposed relationships. Aerosol size distributions were used to compute particle light scattering coefficients and aerosol visible optical depths. The light scattering coefficient for N1 particles ranged from 0.002 to 0.08 1an-1 at altitudes less than 900 m, and from 0.00005 to 0.05 km·1 at higher altitudes. For N2 particles, the light scattering coefficient ranged from 0.001 to 0.05 km-1 for z 900 m. The large particles are a significant contribution to the total aerosol light scattering coefficient. Optical depths for these particles ranged from 0.043 to 0.085 for N1 and from 0.019 to 0.039 for N2.Sponsored by the National Science Foundation (NSF), Significant Opportunities in Atmospheric Research and Science (SOARS)

    Daily rhythmicity of high affinity copper transport

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    A differential demand for copper (Cu) of essential cupro-proteins that act within the mitochondrial and chloroplastal electronic transport chains occurs along the daily light/dark cycles. This requires a fine-tuned spatiotemporal regulation of Cu delivery, becoming especially relevant under non-optimal growth conditions. When scarce, Cu is imported through plasma membrane-bound high affinity Cu transporters (COPTs) whose coding genes are transcriptionally induced by the SPL7 transcription factor. Temporal homeostatic mechanisms are evidenced by the presence of multiple light- and clock-responsive regulatory cis elements in the promoters of both SPL7 and its COPT targets. A model is presented here for such temporal regulation that is based on the synchrony between the basal oscillatory pattern of SPL7 and its targets, such as COPT2. Conversely, Cu feeds back to coordinate intracellular Cu availability on the SPL7-dependent regulation of further Cu acquisition. This occurs via regulation at COPT transporters. Moreover, exogenous Cu affects several circadian-clock components, such as the timing of GIGANTEA transcript abundance. Together we propose that there is a dynamic response to Cu that is integrated over diurnal time to maximize metabolic efficiency under challenging conditions

    Inhibiting the inflammasome with MCC950 counteracts muscle pyroptosis and improves Duchenne muscular dystrophy

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    Background: Duchenne muscular dystrophy (DMD) is the most common inherited human myopathy. Typically, the secondary process involving severe inflammation and necrosis exacerbate disease progression. Previously, we reported that the NLRP3 inflammasome complex plays a crucial role in this disorder. Moreover, pyroptosis, a form of programmed necrotic cell death, is triggered by NLRP3 via gasdermin D (GSDMD). So far, pyroptosis has never been described either in healthy muscle or in dystrophic muscle. The aim of this study was to unravel the role of NLRP3 inflammasome in DMD and explore a potentially promising treatment with MCC950 that selectively inhibits NLRP3. Methods: Four‐week‐old mdx mice (n=6 per group) were orally treated for 2 months with MCC950 (mdx‐T), a highly potent, specific, small-molecule inhibitor of NLRP3, and compared with untreated (mdx) and wild-type (WT) mice. In vivo functional tests were carried out to measure the global force and endurance of mice. Ex vivo biochemical and molecular analyses were performed to evaluate the pathophysiology of the skeletal muscle. Finally, in vitro tests were conducted on primary cultures of DMD human myotubes. Results: After MCC950 treatment, mdx mice exhibited a significant reduction of inflammation, macrophage infiltration and oxidative stress (-20 to -65%, P<0.05 vs untreated mdx). Mdx‐T mice displayed considerably less myonecrosis (-54%, P<0.05 vs mdx) and fibrosis (-75%, P<0.01 vs mdx). Moreover, a more mature myofibre phenotype, characterized by larger-sized fibres and higher expression of mature myosin heavy chains 1 and 7 was observed. Mdx-T also exhibited enhanced force and resistance to fatigue (+20 to 60%, P<0.05 or less). These beneficial effects resulted from MCC950 inhibition of both active caspase-1 (-46%, P=0.075) and cleaved gasdermin D (N-GSDMD) (-42% in medium-sized-fibres, P<0.001). Finally, the anti-inflammatory action and the anti-pyroptotic effect of MCC950 were also recapitulated in DMD human myotubes. Conclusion: Specific inhibition of the NLRP3 inflammasome can significantly attenuate the dystrophic phenotype. A novel finding of this study is the overactivation of GSDMD, which is hampered by MCC950. This ultimately leads to less inflammation and pyroptosis and to a better muscle maturation and function. Targeting NLRP3 might lead to an effective therapeutic approach for a better management of DMD.Fund for Scientific Research de BĂ©lgica (FNRS)-PDR/T.0026.2

    Effectiveness of Atypical Antipsychotic Drugs in Patients with Alzheimer's Disease

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    BACKGROUND Second-generation (atypical) antipsychotic drugs are widely used to treat psychosis, aggression, and agitation in patients with Alzheimer's disease, but their benefits are uncertain and concerns about safety have emerged. We assessed the effectiveness of atypical antipsychotic drugs in outpatients with Alzheimer's disease. METHODS In this 42-site, double-blind, placebo-controlled trial, 421 outpatients with Alzheimer's disease and psychosis, aggression, or agitation were randomly assigned to receive olanzapine (mean dose, 5.5 mg per day), quetiapine (mean dose, 56.5 mg per day), risperidone (mean dose, 1.0 mg per day), or placebo. Doses were adjusted as needed, and patients were followed for up to 36 weeks. The main outcomes were the time from initial treatment to the discontinuation of treatment for any reason and the number of patients with at least minimal improvement on the Clinical Global Impression of Change (CGIC) scale at 12 weeks. RESULTS There were no significant differences among treatments with regard to the time to the discontinuation of treatment for any reason: olanzapine (median, 8.1 weeks), quetiapine (median, 5.3 weeks), risperidone (median, 7.4 weeks), and placebo (median, 8.0 weeks) (P=0.52). The median time to the discontinuation of treatment due to a lack of efficacy favored olanzapine (22.1 weeks) and risperidone (26.7 weeks) as compared with quetiapine (9.1 weeks) and placebo (9.0 weeks) (P=0.002). The time to the discontinuation of treatment due to adverse events or intolerability favored placebo. Overall, 24% of patients who received olanzapine, 16% of patients who received quetiapine, 18% of patients who received risperidone, and 5% of patients who received placebo discontinued their assigned treatment owing to intolerability (P=0.009). No significant differences were noted among the groups with regard to improvement on the CGIC scale. Improvement was observed in 32% of patients assigned to olanzapine, 26% of patients assigned to quetiapine, 29% of patients assigned to risperidone, and 21% of patients assigned to placebo (P=0.22). CONCLUSIONS Adverse effects offset advantages in the efficacy of atypical antipsychotic drugs for the treatment of psychosis, aggression, or agitation in patients with Alzheimer's disease

    Physical Activity Levels in U.S. Latino/Hispanic Adults

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    Physical activity (PA) prevalence among U.S. Latino/Hispanic adults of diverse backgrounds is not well known. This study describes PA among a representative sample of U.S. Latino/Hispanic adults

    Machismo, marianismo, and negative cognitive-emotional factors: Findings from the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study.

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    There is limited research on the traditional Hispanic male and female gender roles of machismo and marianismo, respectively, in relation to negative cognitions and emotions. Given the vulnerability of Hispanics to negative cognitions and emotions, it is important to examine sociocultural correlates of emotional distress. Therefore, we examined associations of machismo and marianismo with negative cognitive-emotional factors (i.e., depression symptoms; cynical hostility; and trait anxiety and anger) in the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study, a cross-sectional cohort study of sociocultural and psychosocial correlates of cardiometabolic health. Participants were aged 18–74 years and self-identified as Hispanic of Central American, Cuban, Dominican, Mexican, Puerto Rican, South American, and other Hispanic background (N = 4,426). Results revealed that specific components of machismo (traditional machismo) and marianismo (family and spiritual pillar dimensions) were associated with higher levels of negative cognitions and emotions after adjusting for socio-demographic factors (p < .05); these associations remained consistent across sex, Hispanic background group, and acculturation. Findings can inform mental health interventions and contribute to our understanding of the importance of gender role socialization in the context of self-reported negative cognitive-emotional factors in Hispanics

    Inflammatory Markers in Schizophrenia: Comparing Antipsychotic Effects in Phase 1 of the CATIE Schizophrenia Trial

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    C-reactive protein (CRP), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin are systemic inflammatory markers (IM) that positively correlate with cardiovascular (CV) risk. Despite the known CV effects of atypical antipsychotics, there is limited prospective data on IM changes during treatment
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