135 research outputs found

    Atmospheric Radiation Measurements Aerosol Intensive Operating Period: Comparison of aerosol scattering during coordinated flights

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    Journal of Geophyshysical Research, Vol. 111, No. D5, D05S09The article of record as published may be located at http://dx.doi.org/10.1029/2005JD006250In May 2003, a Twin Otter airplane, equipped with instruments for making in situ measurements of aerosol optical properties, was deployed during the Atmospheric Radiation Measurements (ARM) Program’s Aerosol Intensive Operational Period in Oklahoma. Several of the Twin Otter flights were flown in formation with an instrumented light aircraft (Cessna 172XP) that makes routine in situ aerosol profile flights over the site. This paper presents comparisons of measured scattering coefficients at 467 nm, 530 nm, and 675 nm between identical commercial nephelometers aboard each aircraft. Overall, the agreement between the two nephelometers decreases with longer wavelength. During the majority of the flights, the Twin Otter flew with a diffuser inlet while the Cessna had a 1 mm impactor, allowing for an estimation of the fine mode fraction aloft. The fine mode fraction aloft was then compared to the results of a ground-based nephelometer. Comparisons are also provided in which both nephelometers operated with identical 1 mm impactors. These scattering coefficient comparisons are favorable at the longer wavelengths (i.e., 530 nm and 675 nm), yet differed by approximately 30% at 467 nm. Mie scattering calculations were performed using size distribution measurements, made during the level flight legs. Results are also presented from Cadenza, a new continuous wave cavity ring-down (CW-CRD) instrument, which compared favorably (i.e., agreed within 2%) with data from other instruments aboard the Twin Otter. With this paper, we highlight the significant implications of coarse mode (larger than 1 mm) aerosol aloft with respect to aerosol optical properties

    Personality Predicts Mortality Risk: An Integrative Data Analysis of 15 International Longitudinal Studies

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    This study examined the Big Five personality traits as predictors of mortality risk, and smoking as a mediator of that association. Replication was built into the fabric of our design: we used a Coordinated Analysis with 15 international datasets, representing 44,094 participants. We found that high neuroticism and low conscientiousness, extraversion, and agreeableness were consistent predictors of mortality across studies. Smoking had a small mediating effect for neuroticism. Country and baseline age explained variation in effects: studies with older baseline age showed a pattern of protective effects (HR<1.00) for openness, and U.S. studies showed a pattern of protective effects for extraversion. This study demonstrated coordinated analysis as a powerful approach to enhance replicability and reproducibility, especially for aging-related longitudinal research.Funding support for this project was provided by the National Institute on Aging: P01-AG043362 (Integrative Analysis of Longitudinal Studies of Aging (IALSA), [Scott M. Hofer (PI)]), and Daniel K. Mroczek (CoInvestigator and Project Leader of the IALSA Personality & Health Project, as well as R01-AG018436 [Personality & Well-Being Trajectories in Adulthood, Daniel K. Mroczek, PI])

    Species difference in ANP32A underlies influenza A virus polymerase host restriction.

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    Influenza pandemics occur unpredictably when zoonotic influenza viruses with novel antigenicity acquire the ability to transmit amongst humans. Host range breaches are limited by incompatibilities between avian virus components and the human host. Barriers include receptor preference, virion stability and poor activity of the avian virus RNA-dependent RNA polymerase in human cells. Mutants of the heterotrimeric viral polymerase components, particularly PB2 protein, are selected during mammalian adaptation, but their mode of action is unknown. We show that a species-specific difference in host protein ANP32A accounts for the suboptimal function of avian virus polymerase in mammalian cells. Avian ANP32A possesses an additional 33 amino acids between the leucine-rich repeats and carboxy-terminal low-complexity acidic region domains. In mammalian cells, avian ANP32A rescued the suboptimal function of avian virus polymerase to levels similar to mammalian-adapted polymerase. Deletion of the avian-specific sequence from chicken ANP32A abrogated this activity, whereas its insertion into human ANP32A, or closely related ANP32B, supported avian virus polymerase function. Substitutions, such as PB2(E627K), were rapidly selected upon infection of humans with avian H5N1 or H7N9 influenza viruses, adapting the viral polymerase for the shorter mammalian ANP32A. Thus ANP32A represents an essential host partner co-opted to support influenza virus replication and is a candidate host target for novel antivirals

    Open Peer Commentary and Author's Response

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    Mõttus gives the impression that composites, as well as other models in which traits are a result rather than a cause of their indicators, require “emergent properties” to have causal power. We argue that this is not necessary; composites can be considered causally relevant by themselves when they mediate the relation between their constituents and the outcome variable

    A Comparative Structural Bioinformatics Analysis of the Insulin Receptor Family Ectodomain Based on Phylogenetic Information

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    The insulin receptor (IR), the insulin-like growth factor 1 receptor (IGF1R) and the insulin receptor-related receptor (IRR) are covalently-linked homodimers made up of several structural domains. The molecular mechanism of ligand binding to the ectodomain of these receptors and the resulting activation of their tyrosine kinase domain is still not well understood. We have carried out an amino acid residue conservation analysis in order to reconstruct the phylogeny of the IR Family. We have confirmed the location of ligand binding site 1 of the IGF1R and IR. Importantly, we have also predicted the likely location of the insulin binding site 2 on the surface of the fibronectin type III domains of the IR. An evolutionary conserved surface on the second leucine-rich domain that may interact with the ligand could not be detected. We suggest a possible mechanical trigger of the activation of the IR that involves a slight ‘twist’ rotation of the last two fibronectin type III domains in order to face the likely location of insulin. Finally, a strong selective pressure was found amongst the IRR orthologous sequences, suggesting that this orphan receptor has a yet unknown physiological role which may be conserved from amphibians to mammals

    Cyanobacterial lipopolysaccharides and human health – a review

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    Cyanobacterial lipopolysaccharide/s (LPS) are frequently cited in the cyanobacteria literature as toxins responsible for a variety of heath effects in humans, from skin rashes to gastrointestinal, respiratory and allergic reactions. The attribution of toxic properties to cyanobacterial LPS dates from the 1970s, when it was thought that lipid A, the toxic moiety of LPS, was structurally and functionally conserved across all Gram-negative bacteria. However, more recent research has shown that this is not the case, and lipid A structures are now known to be very different, expressing properties ranging from LPS agonists, through weak endotoxicity to LPS antagonists. Although cyanobacterial LPS is widely cited as a putative toxin, most of the small number of formal research reports describe cyanobacterial LPS as weakly toxic compared to LPS from the Enterobacteriaceae. We systematically reviewed the literature on cyanobacterial LPS, and also examined the much lager body of literature relating to heterotrophic bacterial LPS and the atypical lipid A structures of some photosynthetic bacteria. While the literature on the biological activity of heterotrophic bacterial LPS is overwhelmingly large and therefore difficult to review for the purposes of exclusion, we were unable to find a convincing body of evidence to suggest that heterotrophic bacterial LPS, in the absence of other virulence factors, is responsible for acute gastrointestinal, dermatological or allergic reactions via natural exposure routes in humans. There is a danger that initial speculation about cyanobacterial LPS may evolve into orthodoxy without basis in research findings. No cyanobacterial lipid A structures have been described and published to date, so a recommendation is made that cyanobacteriologists should not continue to attribute such a diverse range of clinical symptoms to cyanobacterial LPS without research confirmation

    Book Review: Nana Upstairs & Nana Downstairs

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    Comparison of in situ aerosol extinction and scattering coefficient measurements made during the Aerosol Intensive Operating Period

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    Journal of Geophysical Research, Vol. 111, No. D5, D05S03The article of record as published may be located at http://dx.doi.org/10.1029/2005JD006056.In May 2003, the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Program sponsored the Aerosol Intensive Operating Period (AIOP) which was conducted over the ARM Climate Research Facility (ACRF) in central Oklahoma. One new instrument that flew in the AIOP, called Cadenza, employed a cavity ring-down technique to measure extinction coefficient and a reciprocal nephelometer technique to simultaneously measure scattering coefficient. This instrument is described in this paper, and measurements are compared to those of conventional instrumentation. Agreement between Cadenza extinction coefficient and that derived from combining nephelometer scattering and PSAP absorption (Neph + PSAP) was excellent, about 2%. Agreement between Cadenza scattering coefficient and TSI nephelometer scattering was also excellent, about 2%, well within the uncertainty of the nephelometer and Cadenza scattering measurements. Comparisons between these instruments, made for the special case of plumes, showed that Cadenza measured extinction and scattering several percent higher on average than the Neph + PSAP and nephelometer alone. This difference is likely due to differences in the instrument response time: The response time for Cadenza is 1 s while that for the nephelometer is a minimum of 8 s. Plumes, identified as originating from Siberian biomass burning, are characterized. Composite size distributions from wing-mounted probes showed that two of the plumes had significant large particle modes that resulted in high values of the effective radius. The effect of the large particle mode was not seen in the A ° ngstro¨m coefficient calculated from the in-cabin scattering measurements because of the characteristics of the aircraft inlet
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