940 research outputs found

    Seasonal differences in the photochemistry of the South Pacific: A comparison of observations and model results from PEM-Tropics A and B

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    A time-dependent photochemical box model is used to examine the photochemistry of the equatorial and southern subtropical Pacific troposphere with aircraft data obtained during two distinct seasons: the Pacific Exploratory Mission-Tropics A (PEM-Tropics A) field campaign in September and October of 1996 and the Pacific Exploratory Mission-Tropics B (PEM-Tropics B) campaign in March and April of 1999. Model-predicted values were compared to observations for selected species (e.g., NO2, OH, HO2) with generally good agreement. Predicted values of HO2 were larger than those observed in the upper troposphere, in contrast to previous studies which show a general underprediction of HO2 at upper altitudes. Some characteristics of the budgets of HOx, NOx, and peroxides are discussed. The integrated net tendency for O3 is negative over the remote Pacific during both seasons, with gross formation equal to no more than half of the gross destruction. This suggests that a continual supply of O3 into the Pacific region throughout the year must exist in order to maintain O3 levels. Integrated net tendencies for equatorial O3 showed a seasonality, with a net loss of 1.06×1011 molecules cm-2 s-1 during PEM-Tropics B (March) increasing by 50% to 1.60×1011 molecules cm-2 s-1 during PEM-Tropics A (September). The seasonality over the southern subtropical Pacific was somewhat lower, with losses of 1.21×1011 molecules cm-2 s-1 during PEM-Tropics B (March) increasing by 25% to 1.51×1011 molecules cm-2 s-1 during PEM-Tropics A (September). While the larger net losses during PEM-Tropics A were primarily driven by higher concentrations of O3, the ability of the subtropical atmosphere to destroy O3 was ∼30% less effective during the PEM-Tropics A (September) campaign due to a drier atmosphere and higher overhead O3 column amounts. Copyright 2001 by the American Geophysical Union

    Nucleotide sequence and variations of the bovine myocyte enhancer factor 2C (MEF2C) gene promoter in Bos Taurus cattle

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    Myocyte Enhancer Factor 2 (MEF2) proteins are a small family of transcription factors that play pivotal role in morphogenesis and myogenesis of skeletal, cardiac, and smooth muscle cells. In vertebrates, there are four MEF2 genes, referred to as MEF2A, -B, -C, and -D, that are located on different chromosomes. After birth MEF2A, MEF2B, MEF2D transcriptions are expressed ubiquitously, whereas MEF2C transcripts are restricted to skeletal muscle, brain, and spleen. In this study, on the basis of the sequences of the bovine chromosome 7 genomic contig, available in the GenBank database, sets of PCR primers were designed and to amplify the bovine MEF2C gene promoter region, exon 1 (5′UTR) and part sequence of the intron 1. Seven overlapping fragments of the bovine MEF2C gene were amplified and then sequenced. Altogether, these fragments were composed in the 3,120-bp sequence which was deposited in the GenBank database under accession no. GU211007. The sequence fragment included the putative site of the promoter region and transcription start of the exon 1. The sequence analysis of these fragments in individual animals representing different Bos taurus breeds revealed four variations in promoter region: g.-1606C>T, g.-1336_-1335DelG, g.-818C>T, g.-613_-612DelA and four SNPs within intron 1: g.2711A>G, g. 2913A>G, g.2962G>T and g.3014A>G. No polymorphism was found within sequence of the exon 1 (5′UTR). These polymorphisms were identified for first time using these sequences and were confirmed by RFLP or MSSCP methods

    Quantum biology on the edge of quantum chaos

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    We give a new explanation for why some biological systems can stay quantum coherent for long times at room temperatures, one of the fundamental puzzles of quantum biology. We show that systems with the right level of complexity between chaos and regularity can increase their coherence time by orders of magnitude. Systems near Critical Quantum Chaos or Metal-Insulator Transition (MIT) can have long coherence times and coherent transport at the same time. The new theory tested in a realistic light harvesting system model can reproduce the scaling of critical fluctuations reported in recent experiments. Scaling of return probability in the FMO light harvesting complex shows the signs of universal return probability decay observed at critical MIT. The results may open up new possibilities to design low loss energy and information transport systems in this Poised Realm hovering reversibly between quantum coherence and classicality

    Against strong pluralism

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    Strong pluralists hold that not even permanent material coincidence is enough for identity. Strong pluralism entails the possibility of purely material objects -- even if not coincident -- alike in all general respects, categorial and dispositional, relational and non-relational, past, present and future, at the microphysical level, but differing in some general modal, counterfactual or dispositional repscts at the macrophysical level. It is objectionable because it thus deprives us of the explanatory resources to explain why evident absurdities are absurd. A second objection is to the suggestion that cases involving artefacts can illustrate strong pluralism. This offends against the principle that gien a complex intrinsic microphysical property instantiated in some regiion, the number of material things possessing it in that region cannot depend on the existence and nature of intentional activity taking place outside it

    Negative parental responses to coming out and family functioning in a sample of lesbian and gay young adults

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    Parental responses to youths' coming out (CO) are crucial to the subsequent adjustment of children and family. The present study investigated the negative parental reaction to the disclosure of same-sex attraction and the differences between maternal and paternal responses, as reported by their homosexual daughters and sons. Participants' perceptions of their parents' reactions (evaluated through the Perceived Parental Reactions Scale, PPRS), age at coming out, gender, parental political orientation, and religiosity involvement, the family functioning (assessed through the Family Adaptability and Cohesion Evaluation Scales, FACES IV), were assessed in 164 Italian gay and lesbian young adults. Pearson correlation coefficients were calculated to assess the relation between family functioning and parental reaction to CO. The paired sample t-test was used to compare mothers and fathers' scores on the PPRS. Hierarchical multiple regression was conducted to analyze the relevance of each variable. No differences were found between mothers and fathers in their reaction to the disclosure. The analysis showed that a negative reaction to coming out was predicted by parents' right-wing political conservatism, strong religious beliefs, and higher scores in the scales Rigid and Enmeshed. Findings confirm that a negative parental reaction is the result of poor family resources to face a stressful situation and a strong belief in traditional values. These results have important implications in both clinical and social fields

    Complete mitochondrial genomes and nuclear ribosomal RNA operons of two species of Diplostomum (Platyhelminthes: Trematoda): a molecular resource for taxonomy and molecular epidemiology of important fish pathogens

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    © 2015 Brabec et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. The attached file is the published version of the article

    Pneumatosis intestinalis versus pseudo-pneumatosis: review of CT findings and differentiation

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    Pneumatosis intestinalis is defined as the presence of gas within the wall of the gastrointestinal tract. Originally described on plain abdominal radiographs, it is an imaging sign rather than a specific diagnosis and it is associated with both benign and life-threatening clinical conditions. The most common life-threatening cause of pneumatosis intestinalis is bowel ischaemia. Computed tomography (CT) is usually requested to detect underlying disease. The presence of pneumatosis intestinalis often leads physicians to make a diagnosis of serious disease. However, an erroneous diagnosis of pneumatosis intestinalis may be made (i.e. pseudo-pneumatosis) when intraluminal beads of gas are trapped within or between faeces and adjacent mucosal folds. The purpose of this pictorial essay is to review and describe the CT imaging findings of pneumatosis and pseudo-pneumatosis intestinalis and to discuss key discriminatory imaging features
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