2,778 research outputs found

    Tiros VII infrared radiation coverage of the 1963 Atlantic hurricane season with supporting television and conventional meteorological data

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    Infrared radiation data analyzed from Tiros VII SATELLITE coverage of North Atlantic hurricanes during 196

    Classification of Depressional Wetlands in the Great Plains and Development of a Sampling Manual to Predict Playa Ecosystem Services

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    Most depressional wetlands in the Great Plains, an area where wetland losses are estimated to be over 50%, exist in highly cultivated landscapes. The depressional wetlands of the Great Plains include prairie-potholes in the Prairie Pothole Region and playas in the High Plains Region. Both prairie-pothole and playa wetlands provide a host of ecosystem services to society, but service provisioning is greatly influenced by land-use practices that occur both in the wetland and in the surrounding watershed. The most common wetland classification system used to group Great Plains wetlands by type often combines wetlands with of functionally different types into a single grouping, thereby hampering efforts to evaluate ecosystem service provisioning. Thus, my objectives were to 1) develop methodologies, and associated keys, that use aerial and/or satellite imagery and other readily available data sources to place pothole and playa wetlands into hydrogeomorphic function focused groupings to facilitate ecosystem-service assessments, 2) develop a process to remotely determine metrics needed to apply preexisting predictive ecosystem-service models in the playa region and rank the models according to ease of use, and 3) develop a sampling manual for playa wetlands that incorporates the playa-specific key and associated models. Using remotely sensed data, I observed the geomorphic setting of 200 randomly selected palustrine wetlands in each of the two regions and developed a hydrogeomorphic classification key specific to each region. The key included 5 Prairie Pothole Region classes with 12 subclasses and 4 High Plains Region classes with 9 subclasses. The predictive playa ecosystem-service models I evaluated included quantified contaminant filtration, contaminant concentration, pesticide residue, sediment depth, floodwater storage, greenhouse-gas flux, soil organic carbon, plant species richness, amphibian species richness, waterfowl abundance, and avian species richness. I ranked each of these ecosystem-service models by ease of use. The ranking of models resulted in the abiotic-service models being identified as the simplest models to apply and biotic service models as the most complex. I then incorporated the playa-specific hydrogeomorphic key, model rankings and application processes into a sampling manual. The sampling manual included the High Plains Region key and instructions for remotely estimating 10 different playa ecosystem services. This manual will facilitate the identification of wetland function and the estimation of ecosystem services derived from playa wetlands. Use of this manual by natural resource managers would provide information regarding changes in playa wetland service provisioning and inform conservation decisions

    Organophosphorus Pesticides Decrease M2 Muscarinic Receptor Function in Guinea Pig Airway Nerves via Indirect Mechanisms

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    BACKGROUND: Epidemiological studies link organophosphorus pesticide (OP) exposures to asthma, and we have shown that the OPs chlorpyrifos, diazinon and parathion cause airway hyperreactivity in guinea pigs 24 hr after a single subcutaneous injection. OP-induced airway hyperreactivity involves M2 muscarinic receptor dysfunction on airway nerves independent of acetylcholinesterase (AChE) inhibition, but how OPs inhibit neuronal M2 receptors in airways is not known. In the central nervous system, OPs interact directly with neurons to alter muscarinic receptor function or expression; therefore, in this study we tested whether the OP parathion or its oxon metabolite, paraoxon, might decrease M2 receptor function on peripheral neurons via similar direct mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: Intravenous administration of paraoxon, but not parathion, caused acute frequency-dependent potentiation of vagally-induced bronchoconstriction and increased electrical field stimulation (EFS)-induced contractions in isolated trachea independent of AChE inhibition. However, paraoxon had no effect on vagally-induced bradycardia in intact guinea pigs or EFS-induced contractions in isolated ileum, suggesting mechanisms other than pharmacologic antagonism of M2 receptors. Paraoxon did not alter M2 receptor expression in cultured cells at the mRNA or protein level as determined by quantitative RT-PCR and radio-ligand binding assays, respectively. Additionally, a biotin-labeled fluorophosphonate, which was used as a probe to identify molecular targets phosphorylated by OPs, did not phosphorylate proteins in guinea pig cardiac membranes that were recognized by M2 receptor antibodies. CONCLUSIONS/SIGNIFICANCE: These data indicate that neither direct pharmacologic antagonism nor downregulated expression of M2 receptors contributes to OP inhibition of M2 function in airway nerves, adding to the growing evidence of non-cholinergic mechanisms of OP neurotoxicity

    Scanning Tunneling Microscopy and Spectroscopy of Plasmid DNA

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    We present scanning tunneling microscope (STM) images of uncoated deoxyribonucleic acid (DNA) electrochemically mounted on highly-oriented pyrolytic graphite (HOPG) and imaged in air. Images of linear abnormalities inherent to HOPG surfaces that can be confused with DNA are also presented. Scanning tunneling spectroscopic (STS) images generated by superimposing a small, high frequency ac bias onto the de tunnel bias and recording the ac current signal were taken simultaneously with the topographic images. These spectroscopic images reveal contrast due to local conductivity variations and can be used to differentiate DNA molecules from graphite artifacts

    Developing a patient-centered outcome measure for complementary and alternative medicine therapies II: Refining content validity through cognitive interviews

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    BACKGROUND: Available measures of patient-reported outcomes for complementary and alternative medicine (CAM) inadequately capture the range of patient-reported treatment effects. The Self-Assessment of Change questionnaire was developed to measure multi-dimensional shifts in well-being for CAM users. With content derived from patient narratives, items were subsequently focused through interviews on a new cohort of participants. Here we present the development of the final version in which the content and format is refined through cognitive interviews. METHODS: We conducted cognitive interviews across five iterations of questionnaire refinement with a culturally diverse sample of 28 CAM users. In each iteration, participant critiques were used to revise the questionnaire, which was then re-tested in subsequent rounds of cognitive interviews. Following all five iterations, transcripts of cognitive interviews were systematically coded and analyzed to examine participants' understanding of the format and content of the final questionnaire. Based on this data, we established summary descriptions and selected exemplar quotations for each word pair on the final questionnaire. RESULTS: The final version of the Self-Assessment of Change questionnaire (SAC) includes 16 word pairs, nine of which remained unchanged from the original draft. Participants consistently said that these stable word pairs represented opposite ends of the same domain of experience and the meanings of these terms were stable across the participant pool. Five pairs underwent revision and two word pairs were added. Four word pairs were eliminated for redundancy or because participants did not agree on the meaning of the terms. Cognitive interviews indicate that participants understood the format of the questionnaire and considered each word pair to represent opposite poles of a shared domain of experience. CONCLUSIONS: We have placed lay language and direct experience at the center of questionnaire revision and refinement. In so doing, we provide an innovative model for the development of truly patient-centered outcome measures. Although this instrument was designed and tested in a CAM-specific population, it may be useful in assessing multi-dimensional shifts in well-being across a broader patient population

    Biomass Blending and Densification: Impacts on Feedstock Supply and Biochemical Conversion Performance

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    The success of lignocellulosic biofuels and biochemical industries depends on an economic and reliable supply of high‐quality biomass. However, research and development efforts have been historically focused on the utilization of agriculturally derived cellulosic feedstocks, without considerations of their low energy density, high variations in compositions and potential supply risks in terms of availability and affordability. This chapter demonstrated a strategy of feedstock blending and densification to address the supply chain challenges. Blending takes advantage of low‐cost feedstock to avoid the prohibitive costs incurred through reliance on a single feedstock resource, while densification produces feedstocks with increased bulk density and desirable feed handling properties, as well as reduced transportation cost. We also review recent research on the blending and densification dealing with various types of feedstocks with a focus on the impacts of these preprocessing steps on biochemical conversion, that is, various thermochemical pretreatment chemistries and enzymatic hydrolysis, into fermentable sugars for biofuel production

    Alterations in local chromatin environment are involved in silencing and activation of subtelomeric var genes in Plasmodium falciparum

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    Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1), encoded by the var gene family, undergoes antigenic variation and plays an important role in chronic infection and severe malaria. Only a single var gene is transcribed per parasite, and epigenetic control mechanisms are fundamental in this strategy of mutually exclusive transcription. We show that subtelomeric upsB var gene promoters carried on episomes are silenced by default, and that promoter activation is sufficient to silence all other family members. However, they are active by default when placed downstream of a second active var promoter, underscoring the significance of local chromatin environment and nuclear compartmentalization in var promoter regulation. Native chromatin covering the SPE2-repeat array in upsB promoters is resistant to nuclease digestion, and insertion of these regulatory elements into a heterologous promoter causes local alterations in nucleosomal organization and promoter repression. Our findings suggest a common logic underlying the transcriptional control of all var genes, and have important implications for our understanding of the epigenetic processes involved in the regulation of this major virulence gene family

    ISICSoo: a class for the calculation of ionization cross sections from ECPSSR and PWBA theory

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    ISICS, originally a C language program for calculating K-, L- and M-shell ionization and X-ray production cross sections from ECPSSR and PWBA theory, has been reengineered into a C++ language class, named ISICSoo. The new software design enables the use of ISICS functionality in other software systems. The code, originally developed for Microsoft Windows operating systems, has been ported to Linux and Mac OS platforms to facilitate its use in a wider scientific environment. The reengineered software also includes some fixes to the original implementation, which ensure more robust computational results and a review of some physics parameters used in the computation. The paper describes the software design and the modifications to the implementation with respect to the previous version; it also documents the test process and provides some indications about the software performance.Comment: Preprint submitted to Computer Physics Communication

    Blood ties: ABO is a trans-species polymorphism in primates

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    The ABO histo-blood group, the critical determinant of transfusion incompatibility, was the first genetic polymorphism discovered in humans. Remarkably, ABO antigens are also polymorphic in many other primates, with the same two amino acid changes responsible for A and B specificity in all species sequenced to date. Whether this recurrence of A and B antigens is the result of an ancient polymorphism maintained across species or due to numerous, more recent instances of convergent evolution has been debated for decades, with a current consensus in support of convergent evolution. We show instead that genetic variation data in humans and gibbons as well as in Old World Monkeys are inconsistent with a model of convergent evolution and support the hypothesis of an ancient, multi-allelic polymorphism of which some alleles are shared by descent among species. These results demonstrate that the ABO polymorphism is a trans-species polymorphism among distantly related species and has remained under balancing selection for tens of millions of years, to date, the only such example in Hominoids and Old World Monkeys outside of the Major Histocompatibility Complex.Comment: 45 pages, 4 Figures, 4 Supplementary Figures, 5 Supplementary Table
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