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Sample records for factor multimer distribution

  1. Update on von Willebrand factor multimers: focus on high-molecular-weight multimers and their role in hemostasis

    PubMed Central

    Stockschlaeder, Marcus; Schneppenheim, Reinhard; Budde, Ulrich

    2014-01-01

    Normal hemostasis requires von Willebrand factor (VWF) to support platelet adhesion and aggregation at sites of vascular injury. VWF is a multimeric glycoprotein built from identical subunits that contain binding sites for both platelet glycoprotein receptors and collagen. The adhesive activity of VWF depends on the size of its multimers, which range from 500 to over 10 000 kDa. There is good evidence that the high-molecular-weight multimers (HMWM), which are 5000–10 000 kDa, are the most effective in supporting interaction with collagen and platelet receptors and in facilitating wound healing under conditions of shear stress. Thus, these HMWM of VWF are of particular clinical interest. The unusually large multimers of VWF are, under normal conditions, cleaved by the plasma metalloproteinase ADAMTS13 to smaller, less adhesive multimers. A reduction or lack of HMWM, owing to a multimerization defect of VWF or to an increased susceptibility of VWF for ADAMTS13, leads to a functionally impaired VWF and the particular type 2A of von Willebrand disease. This review considers the biology and function of VWF multimers with a particular focus on the characterization of HMWM – their production, storage, release, degradation, and role in normal physiology. Evidence from basic research and the study of clinical diseases and their management highlight a pivotal role for the HMWM of VWF in hemostasis. PMID:24448155

  2. von Willebrand Factor multimers profiling with a semi-automated system.

    PubMed

    Pasotti, Fabio; Martini, Giuliana; Caimi, Luigi; Ricotta, Doris

    2013-03-01

    Abnormalities in plasma von Willebrand factor (vWF) concentration and function result in von Willebrand disease (vWD). The diagnosis requires a battery of tests such as screening procedures, confirmatory tests, phenotypic characterization, and genotyping. The phenotypic testing (multimer pattern analysis) is important in order to subclassify the hereditary and the acquired forms of vWD. Only few laboratories are skilled to perform this analysis. The extreme range of protein size from 250 kDa monomer to over 20,000 kDa multimers requires a time-consuming procedure (3-4 days) and presents many technical difficulties. To standardize the method and to overcome technical difficulties, we developed a rapid and sensitive semi-automated method to visualize the multimeric structure of vWF. The semi-automated method we present performs the electrophoresis of patient's plasma in 120 min on a precast gel. Gels are suitable for the G26 Interlab instrumentation. After gel blotting, the method allows visualization of the vWF multimer pattern directly on the membrane. We reduced the time required from 72 to 8 h and we propose this test for the first level screening of vWF multimer deficiency. PMID:23334940

  3. Lack of multimer organization of von Willebrand factor in an acquired von Willebrand syndrome.

    PubMed

    Casonato, A; Pontara, E; Doria, A; Bertomoro, A; Cattini, M G; Gambari, P F; Girolami, A

    2002-03-01

    We report a case of acquired von Willebrand syndrome (AVWS) in a 20-year-old-woman with systemic lupus erythematosus, in whom severe bleeding complications followed kidney biopsy. Coagulation studies demonstrated undetectable levels of ristocetin-induced platelet aggregation (RIPA), von Willebrand factor antigen (VWF:Ag) and VWF ristocetin cofactor activity (VWF:RCo), associated with significantly prolonged bleeding time; unlike type 3 von Willebrand disease (VWD), platelet VWF was reduced but not undetectable. The plasma VWF multimer pattern was characterized by the presence of only two bands, one of low molecular weight (MW) running as the protomer of plasma VWF in normals, the other of abnormally high MW without detectable intermediate multimers; this pattern resembles that of VWF present in endothelial cells. A search for an anti-VWF antibody demonstrated the presence of an inhibitor at high titre. This anti-VWF antibody did not interfere in the interaction of VWF with platelet glycoprotein (GP) Ib through the A1 domain, and did not react with the A2 domain of VWF; instead, it seemed to modify the relative representation of high and low MW VWF multimers released by normal human umbilical vein endothelial cells (HUVEC). After Azathioprine and corticosteroid treatment, the anti-VWF antibody disappeared and the patient's haemostatic profile normalized, except for the platelet VWF content which still remained decreased. We suggest that the anti-VWF antibody present in the AVWS described compromised both circulating VWF levels and their multimeric organization, inducing the maintenance of the multimer structure that VWF normally has before or in the early phase after secretion from endothelial cells. PMID:11886398

  4. Granulocyte proteases do not process endothelial cell-derived unusually large von Willebrand factor multimers to plasma vWF in vivo.

    PubMed

    Phillips, M D; Vu, C; Nolasco, L; Moake, J L

    1991-06-01

    The unusually large von Willebrand factor (ULvWF) multimers present within endothelial cells and platelets are larger than the vWF multimers normally found in adult human plasma. Furthermore, ULvWF multimers are cleared rapidly from the circulation if they are released by intense endothelial cell stimulation. The mechanisms by which the ULvWF multimers are processed to large plasma vWF multimers are not known. It has been demonstrated that granulocyte proteases are capable of decreasing vWF multimer size in vitro, and that some patients with myeloproliferative syndromes have a relative absence of large plasma vWF multimers in sodium citrate-anticoagulated plasma samples. In order to assess the influence of granulocyte proteases on vWF multimer size, we evaluated the vWF multimeric patterns in 94 plasma samples from 60 patients with neutrophil counts that were either considerably elevated or extremely reduced. In 83 of 94 plasma samples, the vWF multimeric patterns were normal. No patients with very low neutrophil counts had ULvWF multimers present. These observations suggest that granulocyte proteases are not likely to be involved in vivo in the processing of ULvWF multimers from endothelial cells to the smaller vWF forms in circulation. PMID:2069167

  5. Increased von Willebrand factor antigen and high molecular weight multimers in sickle cell disease associated with nocturnal hypoxemia.

    PubMed

    Krishnan, Suba; Siegel, Jamie; Pullen, Gene; Hevelow, Megan; Dampier, Carlton; Stuart, Marie

    2008-01-01

    We evaluated vWF profiles in children and adolescents with SCD and sleep hypoxemia. Mean vWF:Ag levels were significantly elevated in the SCD-hypoxemia group when compared with SCD-normoxia and control groups (p=0.007); and correlated inversely with pulse oximetry (r=-0.54, p=0.01). Densitographic analyses of vWF multimer distribution also showed an inverse correlation between %HMW-multimers and oxygen saturation (r=-0.62, p=0.03). The previously reported association between nocturnal desaturation and SCD vascular complications, including stroke, may be influenced by hypoxemic modulation of vWF as noted in this study. PMID:18230405

  6. An explanation for minor multimer species in endothelial cell-synthesized von Willebrand factor.

    PubMed Central

    Lynch, D C; Zimmerman, T S; Ling, E H; Browning, P J

    1986-01-01

    Initial synthesis of von Willebrand factor (vWf) by cultured human endothelial cells proceeds by formation of a dimer of pro-vWf subunits. These subunits are found only within the cell and have an apparent molecular weight of 240,000-260,000, as measured by electrophoresis in sodium dodecyl sulfate-polyacrylamide gels. Posttranslational modifications, including proteolytic cleavage, glycosylation, and sulfation, result in the appearance of two additional vWf subunits. The major one migrates with the subunit of plasma vWf at an apparent molecular weight of 220,000-225,000 and the other migrates more slowly than pro-vWf at an apparent molecular weight of 260,000-275,000. These subunits oligomerize to form a set of vWf multimers, which are subsequently secreted into the culture medium. We isolated individual vWf oligomer species from the agarose gel bands and show that vWf minor, or satellite, species differ from major species in subunit composition. Images PMID:3486890

  7. An explanation for minor multimer species in endothelial cell-synthesized von Willebrand factor.

    PubMed

    Lynch, D C; Zimmerman, T S; Ling, E H; Browning, P J

    1986-06-01

    Initial synthesis of von Willebrand factor (vWf) by cultured human endothelial cells proceeds by formation of a dimer of pro-vWf subunits. These subunits are found only within the cell and have an apparent molecular weight of 240,000-260,000, as measured by electrophoresis in sodium dodecyl sulfate-polyacrylamide gels. Posttranslational modifications, including proteolytic cleavage, glycosylation, and sulfation, result in the appearance of two additional vWf subunits. The major one migrates with the subunit of plasma vWf at an apparent molecular weight of 220,000-225,000 and the other migrates more slowly than pro-vWf at an apparent molecular weight of 260,000-275,000. These subunits oligomerize to form a set of vWf multimers, which are subsequently secreted into the culture medium. We isolated individual vWf oligomer species from the agarose gel bands and show that vWf minor, or satellite, species differ from major species in subunit composition. PMID:3486890

  8. P-selectin anchors newly released ultralarge von Willebrand factor multimers to the endothelial cell surface.

    PubMed

    Padilla, Arnoldo; Moake, Joel L; Bernardo, Aubrey; Ball, Chalmette; Wang, Yongtao; Arya, Maneesh; Nolasco, Leticia; Turner, Nancy; Berndt, Michael C; Anvari, Bahman; López, José A; Dong, Jing-Fei

    2004-03-15

    von Willebrand factor (VWF) released from endothelium is ultralarge (UL) and hyperreactive. If released directly into plasma, it can spontaneously aggregate platelets, resulting in systemic thrombosis. This disastrous consequence is prevented by the ADAMTS13 (ADisintegrin and Metalloprotease with ThromboSpondin motif) cleavage of ULVWF into smaller, less active forms. We previously showed that ULVWF, on release, forms extremely long stringlike structures. ADAMTS13 cleaves these strings under flow significantly faster than it does under static conditions. As ULVWF tethering to endothelium is important for its rapid proteolysis, we investigated 2 molecules for their potential to anchor the ULVWF strings: P-selectin and integrin alpha v beta 3. We demonstrated that P-selectin anchors ULVWF to endothelium by several means. First, Chinese hamster ovary (CHO) cells expressing P-selectin specifically adhered to immobilized ULVWF and ULVWF-coated beads to immobilized P-selectin. Second, an anti-VWF antibody coimmunoprecipitates P-selectin from the histamine-activated endothelial cells. Third, P-selectin antibody or soluble P-selectin, but not a alpha v beta 3 antibody, RGDS peptide, or heparin, blocked the formation of ULVWF strings. Fourth, P-selectin expression was in clusters predominantly along the ULVWF strings. Finally, the strength of the minimal ULVWF-P-selectin bond was measured to be 7.2 pN. We, therefore, conclude that P-selectin may anchor ULVWF strings to endothelial cells and facilitate their cleavage by ADAMTS13. PMID:14630802

  9. Characterization of α-Synuclein Multimer Stoichiometry in Complex Biological Samples by Electrophoresis.

    PubMed

    Killinger, Bryan A; Moszczynska, Anna

    2016-04-01

    The aberrant aggregation of α-synuclein in the brain is a hallmark of Parkinson's disease (PD). In vivo soluble α-synuclein occurs as a monomer and several multimers, the latter of which may be important for the biological function of α-synuclein. Currently, there is a lack of reproducible methods to compare α-synuclein multimer abundance between complex biological samples. Here we developed a method, termed "multimer-PAGE," that combines in-gel chemical cross-linking with several common electrophoretic techniques to measure the stoichiometry of soluble α-synuclein multimers in brain tissue lysates. Results show that soluble α-synuclein from the rat brain exists as several high molecular weight species of approximately 56 kDa (αS56), 80 kDa (αS80), and 100 kDa (αS100) that comigrate with endogenous lipids, detergents, and/or micelles during blue native gel electrophoresis (BN-PAGE). Co-extraction of endogenous lipids with α-synuclein was essential for the detection of soluble α-synuclein multimers. Homogenization of brain tissue in small buffer volumes (>50 mg tissue per 1 mL buffer) increased relative lipid extraction and subsequently resulted in abundant soluble multimer detection via multimer-PAGE. α-Synuclein multimers captured by directly cross-linking soluble lysates resembled those observed following multimer-PAGE. The ratio of multimer (αS80) to monomer (αS17) increased linearly with protein input into multimer-PAGE, suggesting to some extent, multimers were also formed during electrophoresis. Overall, soluble α-synuclein maintains lipid interactions following tissue disruption and readily forms multimers when this lipid-protein complex is preserved. Once the multimer-PAGE technique was validated, relative stoichiometric comparisons could be conducted simultaneously between 14 biological samples. Multimer-PAGE provides a simple inexpensive biochemical technique to study the molecular factors influencing α-synuclein multimerization. PMID

  10. Ribonucleoprotein multimers and their functions

    PubMed Central

    Bleichert, Franziska; Baserga, Susan J.

    2010-01-01

    Ribonucleoproteins (RNPs) play key roles in many cellular processes and often function as RNP enzymes. Similar to proteins, some of these RNPs exist and function as multimers, either momomeric or heteromeric. While in some cases the mechanistic function of multimerization is well understood, the functional consequences of multimerization of other RNPs remain enigmatic. In this review we will discuss the function and organization of small RNPs that exist as stable multimers, including RNPs catalyzing RNA chemical modifications, telomerase RNP, and RNPs involved in pre-mRNA splicing. PMID:20572804

  11. MULTIMEDIA EXPOSURE ASSESSMENT MODEL (MULTIMED)

    EPA Science Inventory

    The Multimedia Exposure Assessment Model (MULTIMED) for exposure assessment simulates the movement of contaminants leaching from a waste disposal facility. The model consists of a number of modules which predict concentrations at a receptor due to transport in the subsurface, sur...

  12. Characterization of α-Synuclein Multimer Stoichiometry in Complex Biological Samples by Electrophoresis

    PubMed Central

    2016-01-01

    The aberrant aggregation of α-synuclein in the brain is a hallmark of Parkinson’s disease (PD). In vivo soluble α-synuclein occurs as a monomer and several multimers, the latter of which may be important for the biological function of α-synuclein. Currently, there is a lack of reproducible methods to compare α-synuclein multimer abundance between complex biological samples. Here we developed a method, termed “multimer-PAGE,” that combines in-gel chemical cross-linking with several common electrophoretic techniques to measure the stoichiometry of soluble α-synuclein multimers in brain tissue lysates. Results show that soluble α-synuclein from the rat brain exists as several high molecular weight species of approximately 56 kDa (αS56), 80 kDa (αS80), and 100 kDa (αS100) that comigrate with endogenous lipids, detergents, and/or micelles during blue native gel electrophoresis (BN-PAGE). Co-extraction of endogenous lipids with α-synuclein was essential for the detection of soluble α-synuclein multimers. Homogenization of brain tissue in small buffer volumes (>50 mg tissue per 1 mL buffer) increased relative lipid extraction and subsequently resulted in abundant soluble multimer detection via multimer-PAGE. α-Synuclein multimers captured by directly cross-linking soluble lysates resembled those observed following multimer-PAGE. The ratio of multimer (αS80) to monomer (αS17) increased linearly with protein input into multimer-PAGE, suggesting to some extent, multimers were also formed during electrophoresis. Overall, soluble α-synuclein maintains lipid interactions following tissue disruption and readily forms multimers when this lipid–protein complex is preserved. Once the multimer-PAGE technique was validated, relative stoichiometric comparisons could be conducted simultaneously between 14 biological samples. Multimer-PAGE provides a simple inexpensive biochemical technique to study the molecular factors influencing α-synuclein multimerization

  13. Exponential Size Distribution of von Willebrand Factor

    PubMed Central

    Lippok, Svenja; Obser, Tobias; Müller, Jochen P.; Stierle, Valentin K.; Benoit, Martin; Budde, Ulrich; Schneppenheim, Reinhard; Rädler, Joachim O.

    2013-01-01

    Von Willebrand Factor (VWF) is a multimeric protein crucial for hemostasis. Under shear flow, it acts as a mechanosensor responding with a size-dependent globule-stretch transition to increasing shear rates. Here, we quantify for the first time, to our knowledge, the size distribution of recombinant VWF and VWF-eGFP using a multilateral approach that involves quantitative gel analysis, fluorescence correlation spectroscopy, and total internal reflection fluorescence microscopy. We find an exponentially decaying size distribution of multimers for recombinant VWF as well as for VWF derived from blood samples in accordance with the notion of a step-growth polymerization process during VWF biosynthesis. The distribution is solely described by the extent of polymerization, which was found to be reduced in the case of the pathologically relevant mutant VWF-IIC. The VWF-specific protease ADAMTS13 systematically shifts the VWF size distribution toward smaller sizes. This dynamic evolution is monitored using fluorescence correlation spectroscopy and compared to a computer simulation of a random cleavage process relating ADAMTS13 concentration to the degree of VWF breakdown. Quantitative assessment of VWF size distribution in terms of an exponential might prove to be useful both as a valuable biophysical characterization and as a possible disease indicator for clinical applications. PMID:24010664

  14. Changes in the pattern of distribution of von Willebrand factor in rat aortic endothelial cells following thrombin generation in vivo.

    PubMed

    Senis, Y A; Richardson, M; Tinlin, S; Maurice, D H; Giles, A R

    1996-04-01

    The pattern of distribution of von Willebrand factor (VWF) in relatively large sheets of rat aortic endothelial cells (EC) obtained by the Häutchen technique were analysed by immunocytochemistry and light microscopy. EC were examined pre and post administration of a procoagulant mixture of factor Xa (F.Xa) and phosphotidylcholine/phosphotidylserine (PCPS) vesicles which was demonstrated to result in the selective loss of high molecular weight multimers (HMWM) of plasma VWF in the rat. In placebo animals the pattern was heterogenous both in overall distribution and in individual cells which showed both a diffuse and granular pattern. Groups of intensely stained EC were oriented parallel to the longitudinal axis of the aorta and staining was particularly prominent around the orifices of the intercostal arteries, implicating shear-stress as a possible factor in VWF expression by EC. Changes in the pattern of distribution of staining were observed at various time points post-infusion of F.Xa/PCPS, suggesting the immediate release of VWF from EC stores followed by the recruitment of EC to synthesize and store VWF. These changes are consistent with the decrease in EC Weibel-Palade Body (WPB) content observed by EM in previously reported studies using this model. PMID:8611460

  15. A Versatile Simple Capture Assay for Assessing the Structural Integrity of MHC Multimer Reagents

    PubMed Central

    Malo, Courtney S.; Renner, Danielle N.; Van Keulen, Virginia S.; Girtman, Megan A.; Nevala, Wendy N.; Pavelko, Kevin D.; Gil, Diana; Schrum, Adam G.; Johnson, Aaron J.; Pease, Larry R.

    2015-01-01

    Antigen-specific T cell responses can be visualized using MHC:peptide multimers. In cases where robust T cell controls are not readily available to assess the integrity of multimer reagents prior to analyzing limited sample, the ability to assess the structural integrity of MHC multimers before their use in critical experiments would be useful. We present a method to probe the structural integrity of MHC multimers using antibodies specific for conformational determinants. Beads coated with anti-mouse Ig are incubated with conformation-specific mouse monoclonal antibody and then with fluorescently tagged MHC multimer. The ability of the bead to capture the labeled multimer can be measured semi-quantitatively by flow cytometry. In this manner, the correct folding of MHC multimers can be visualized and batches of multimer can be compared for quality control. Because there are multiple conformational epitopes formed by various molecular interactions among heavy chain, peptide, and β2M, this capture assay can assess the fidelity of each aspect of multimer structure, depending on the availability of antibodies. The described approach could be particularly useful for studies using irreplaceable samples, including patient samples collected in clinical trials. PMID:26389800

  16. Tuberculosis: distribution, risk factors, mortality.

    PubMed

    Kochi, A

    1994-10-01

    About a century after Koch's discovery of the TB bacilli the tuberculosis epidemic which had appeared to be under control was again recognized as a major global health threat. The decline in the epidemic in this century had been largely through the improved living standards and, eventually, the availability and use of effective antibiotics. While tuberculosis gradually disappeared from the health agenda in the western world it remained a big killer throughout the century and in 1992 an estimated 2.7 million TB deaths occurred; 30 million will die from TB during the 1990s if current trends are not reversed. The annual number of new cases will increase from 7.5 million estimated in 1990 to more than 10 million in the year 2000. The main factors for this increase are demographic forces, population movements, the HIV epidemic and increasing drug resistance. The impact of the HIV epidemic is already felt in many sub-Saharan African countries and now threatens Asia where almost two-thirds of the world's TB infected population live and where HIV is spreading. Tuberculosis has also reemerged as a major public health problem in industrialized countries due to international migration, the breakdown of health services, including TB services etc. The control of the epidemic can only be through a concerted action to reinstate TB as priority among health concerns, reflected in national and international resources. A coalition of public and private supporters must be mobilized to support the effort to fight the disease. Governments, non-governmental organizations, the business community, refugee organizations, medical institutions, and other UN agencies are invited to join with WHO in this effort. PMID:7713546

  17. FACTORS AND PRACTICES THAT INFLUENCE LIVESTOCK DISTRIBUTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inconsistent livestock distribution in extensive rangeland pastures continues as a vexing problem for land and livestock managers. Dispersal patterns of cattle are affected by abiotic factors like degree of slope, distance from water, shade, physical barriers, temperature extremes and precipitation...

  18. Nucleon Form Factors from Generalized Parton Distributions

    SciTech Connect

    M. Guidal; Maxim Polyakov; Anatoly Radyushkin; Marc Vanderhaeghen

    2004-10-01

    We discuss the links between Generalized Parton Distributions (GPDs) and elastic nucleon form factors. These links, in the form of sum rules, represent powerful constraints on parametrizations of GPDs. A Regge parametrization for GPDs at small momentum transfer, is extended to the large momentum transfer region and it is found to describe the basic features of proton and neutron electromagnetic form factor data. This parametrization is used to estimate the quark contribution to the nucleon spin.

  19. Interrogating the repertoire: broadening the scope of peptide-MHC multimer analysis.

    PubMed

    Davis, Mark M; Altman, John D; Newell, Evan W

    2011-08-01

    Labelling antigen-specific T cells with peptide-MHC multimers has provided an invaluable way to monitor T cell-mediated immune responses. A number of recent developments in this technology have made these multimers much easier to make and use in large numbers. Furthermore, enrichment techniques have provided a greatly increased sensitivity that allows the analysis of the naive T cell repertoire directly. Thus, we can expect a flood of new information to emerge in the coming years. PMID:21760610

  20. Cryopreservation of MHC Multimers: Recommendations for Quality Assurance in Detection of Antigen Specific T Cells

    PubMed Central

    Hadrup, Sine Reker; Maurer, Dominik; Laske, Karoline; Frøsig, Thomas Mørch; Andersen, Sofie Ramskov; Britten, Cedrik M; van der Burg, Sjoerd H; Walter, Steffen; Gouttefangeas, Cécile

    2015-01-01

    Fluorescence-labeled peptide-MHC class I multimers serve as ideal tools for the detection of antigen-specific T cells by flow cytometry, enabling functional and phenotypical characterization of specific T cells at the single cell level. While this technique offers a number of unique advantages, MHC multimer reagents can be difficult to handle in terms of stability and quality assurance. The stability of a given fluorescence-labeled MHC multimer complex depends on both the stability of the peptide-MHC complex itself and the stability of the fluorochrome. Consequently, stability is difficult to predict and long-term storage is generally not recommended. We investigated here the possibility of cryopreserving MHC multimers, both in-house produced and commercially available, using a wide range of peptide-MHC class I multimers comprising virus and cancer-associated epitopes of different affinities presented by various HLA-class I molecules. Cryopreservation of MHC multimers was feasible for at least 6 months, when they were dissolved in buffer containing 5–16% glycerol (v/v) and 0.5% serum albumin (w/v). The addition of cryoprotectants was tolerated across three different T-cell staining protocols for all fluorescence labels tested (PE, APC, PE-Cy7 and Quantum dots). We propose cryopreservation as an easily implementable method for stable storage of MHC multimers and recommend the use of cryopreservation in long-term immunomonitoring projects, thereby eliminating the variability introduced by different batches and inconsistent stability. © 2014 International Society for Advancement of Cytometry PMID:25297339

  1. Seed dormancy distribution: explanatory ecological factors

    PubMed Central

    Wagmann, Kristen; Hautekèete, Nina-Coralie; Piquot, Yves; Meunier, Cécile; Schmitt, S. Eric; Van Dijk, Henk

    2012-01-01

    Background and Aims Knowledge of those traits that vary with latitude should be helpful in predicting how they may evolve locally under climate change. In the sea beet Beta vulgaris ssp. maritima, seed dormancy largely controls the timing of germination, is highly heritable and varies geographically; it is therefore thought to be selected by climate. The aim here was to characterize the variation in seed dormancy among sea beet populations across the French distribution area, as well as the ecological factors in situ that are correlated with and that could therefore select for seed dormancy. The relative importance of genetic inheritance vs. non-genetic variation is also evaluated. Methods The proportions of dormant seeds from 85 natural populations encompassing different climates over the whole French distribution area were measured under controlled conditions. Germination phenology was observed in a common garden experiment. Dormancy variation of seeds collected in situ was compared with that of seeds collected on plants grown in the greenhouse. Key Results The proportions of dormant seeds in the greenhouse were highly variable, covering almost the entire range from 0 to 1, and followed a geographical pattern from lower dormancy at high latitudes to high dormancy at low latitudes. The distribution of dormancy was positively correlated with yearly temperatures, especially summer temperatures. Minimum temperatures in winter did not significantly explain the trait variation. The genetic component of the total variation was significant and is probably completed by an important adjustment to the local conditions brought about by maternal adaptive phenotypic plasticity. Conclusions Dormancy in sea beet could be interpreted as a way to limit summer germination and spread germination over the first autumn and spring or following autumns. This highly heritable trait has the potential to evolve in the relatively near future because of climate change. PMID:22952378

  2. Single domain antibody multimers confer protection against rabies infection.

    PubMed

    Boruah, Bhargavi M; Liu, Dawei; Ye, Duan; Gu, Tie-Jun; Jiang, Chun-Lai; Qu, Mingsheng; Wright, Edward; Wang, Wei; He, Wen; Liu, Changzhen; Gao, Bin

    2013-01-01

    Post-exposure prophylactic (PEP) neutralizing antibodies against Rabies are the most effective way to prevent infection-related fatality. The outer envelope glycoprotein of the Rabies virus (RABV) is the most significant surface antigen for generating virus-neutralizing antibodies. The small size and uncompromised functional specificity of single domain antibodies (sdAbs) can be exploited in the fields of experimental therapeutic applications for infectious diseases through formatting flexibilities to increase their avidity towards target antigens. In this study, we used phage display technique to select and identify sdAbs that were specific for the RABV glycoprotein from a naïve llama-derived antibody library. To increase their neutralizing potencies, the sdAbs were fused with a coiled-coil peptide derived from the human cartilage oligomeric matrix protein (COMP48) to form homogenous pentavalent multimers, known as combodies. Compared to monovalent sdAbs, the combodies, namely 26424 and 26434, exhibited high avidity and were able to neutralize 85-fold higher input of RABV (CVS-11 strain) pseudotypes in vitro, as a result of multimerization, while retaining their specificities for target antigen. 26424 and 26434 were capable of neutralizing CVS-11 pseudotypes in vitro by 90-95% as compared to human rabies immunoglobulin (HRIG), currently used for PEP in Rabies. The multimeric sdAbs were also demonstrated to be partially protective for mice that were infected with lethal doses of rabies virus in vivo. The results demonstrate that the combodies could be valuable tools in understanding viral mechanisms, diagnosis and possible anti-viral candidate for RABV infection. PMID:23977032

  3. A Comparison of Distribution Free and Non-Distribution Free Factor Analysis Methods

    ERIC Educational Resources Information Center

    Ritter, Nicola L.

    2012-01-01

    Many researchers recognize that factor analysis can be conducted on both correlation matrices and variance-covariance matrices. Although most researchers extract factors from non-distribution free or parametric methods, researchers can also extract factors from distribution free or non-parametric methods. The nature of the data dictates the method…

  4. Virtuality Distributions and Pion Transition Form Factor

    DOE PAGESBeta

    Radyushkin, Anatoly V.

    2015-03-01

    Using the example of hard exclusive transition process γ*γ → π0 at the handbag level, we outline basics of a new approach to transverse momentum dependence in hard processes. In coordinate representation, matrix elements of operators (in the simplest case, bilocal O(0,z)) describing a hadron with momentum p, are functions of (pz) and z2 parametrized through virtuality distribution amplitudes (VDA) Φ(x, σ), with x being Fourier-conjugate to (pz) and σ Laplace-conjugate to z2. For intervals with z+=0, we introduce the transverse momentum distribution amplitude (TMDA) Ψ(x, k_perp), and write it in terms of VDA Φ(x,σ). We propose models for softmore » VDAs/TMDAs, and use them for comparison of handbag results with experimental (BaBar and BELLE) data. We also discuss the generation of hard tails of TMDAs from initially soft forms.« less

  5. Virtuality Distributions and Pion Transition Form Factor

    NASA Astrophysics Data System (ADS)

    Radyushkin, A. V.

    2015-02-01

    Using the example of hard exclusive transition process γ*γ → π0 at the handbag level, we outline basics of a new approach to transverse momentum dependence in hard processes. In coordinate representation, matrix elements of operators (in the simplest case, bilocal 𝒪(0, z)) describing a hadron with momentum p, are functions of (pz) and z2 parametrized through virtuality distribution amplitudes (VDA) Φ(x, σ), with x being Fourier-conjugate to (pz) and σ Laplace-conjugate to z2. For intervals with z+ = 0, we introduce the transverse momentum distribution amplitude (TMDA) Ψ(x, k⊥), and write it in terms of VDA Φ(x, σ). We propose models for soft VDAs/TMDAs, and use them for comparison of handbag results with experimental (BaBar and BELLE) data. We also discuss the generation of hard tails of TMDAs from initially soft forms.

  6. Geological factors affecting CO2 plume distribution

    USGS Publications Warehouse

    Frailey, S.M.; Leetaru, H.

    2009-01-01

    Understanding the lateral extent of a CO2 plume has important implications with regards to buying/leasing pore volume rights, defining the area of review for an injection permit, determining the extent of an MMV plan, and managing basin-scale sequestration from multiple injection sites. The vertical and lateral distribution of CO2 has implications with regards to estimating CO2 storage volume at a specific site and the pore pressure below the caprock. Geologic and flow characteristics such as effective permeability and porosity, capillary pressure, lateral and vertical permeability anisotropy, geologic structure, and thickness all influence and affect the plume distribution to varying degrees. Depending on the variations in these parameters one may dominate the shape and size of the plume. Additionally, these parameters do not necessarily act independently. A comparison of viscous and gravity forces will determine the degree of vertical and lateral flow. However, this is dependent on formation thickness. For example in a thick zone with injection near the base, the CO2 moves radially from the well but will slow at greater radii and vertical movement will dominate. Generally the CO2 plume will not appreciably move laterally until the caprock or a relatively low permeability interval is contacted by the CO2. Conversely, in a relatively thin zone with the injection interval over nearly the entire zone, near the wellbore the CO2 will be distributed over the entire vertical component and will move laterally much further with minimal vertical movement. Assuming no geologic structure, injecting into a thin zone or into a thick zone immediately under a caprock will result in a larger plume size. With a geologic structure such as an anticline, CO2 plume size may be restricted and injection immediately below the caprock may have less lateral plume growth because the structure will induce downward vertical movement of the CO2 until the outer edge of the plume reaches a spill

  7. Virtuality Distributions and Pion Transition Form Factor

    SciTech Connect

    Radyushkin, Anatoly V.

    2015-03-01

    Using the example of hard exclusive transition process γ*γ → π0 at the handbag level, we outline basics of a new approach to transverse momentum dependence in hard processes. In coordinate representation, matrix elements of operators (in the simplest case, bilocal O(0,z)) describing a hadron with momentum p, are functions of (pz) and z2 parametrized through virtuality distribution amplitudes (VDA) Φ(x, σ), with x being Fourier-conjugate to (pz) and σ Laplace-conjugate to z2. For intervals with z+=0, we introduce the transverse momentum distribution amplitude (TMDA) Ψ(x, k_perp), and write it in terms of VDA Φ(x,σ). We propose models for soft VDAs/TMDAs, and use them for comparison of handbag results with experimental (BaBar and BELLE) data. We also discuss the generation of hard tails of TMDAs from initially soft forms.

  8. Standardized approach for developing probabilistic exposure factor distributions

    SciTech Connect

    Maddalena, Randy L.; McKone, Thomas E.; Sohn, Michael D.

    2003-03-01

    The effectiveness of a probabilistic risk assessment (PRA) depends critically on the quality of input information that is available to the risk assessor and specifically on the probabilistic exposure factor distributions that are developed and used in the exposure and risk models. Deriving probabilistic distributions for model inputs can be time consuming and subjective. The absence of a standard approach for developing these distributions can result in PRAs that are inconsistent and difficult to review by regulatory agencies. We present an approach that reduces subjectivity in the distribution development process without limiting the flexibility needed to prepare relevant PRAs. The approach requires two steps. First, we analyze data pooled at a population scale to (1) identify the most robust demographic variables within the population for a given exposure factor, (2) partition the population data into subsets based on these variables, and (3) construct archetypal distributions for each subpopulation. Second, we sample from these archetypal distributions according to site- or scenario-specific conditions to simulate exposure factor values and use these values to construct the scenario-specific input distribution. It is envisaged that the archetypal distributions from step 1 will be generally applicable so risk assessors will not have to repeatedly collect and analyze raw data for each new assessment. We demonstrate the approach for two commonly used exposure factors--body weight (BW) and exposure duration (ED)--using data for the U.S. population. For these factors we provide a first set of subpopulation based archetypal distributions along with methodology for using these distributions to construct relevant scenario-specific probabilistic exposure factor distributions.

  9. The Use of Peptide–Major-Histocompatibility-Complex Multimers in Type 1 Diabetes Mellitus

    PubMed Central

    Gojanovich, Greg S; Murray, Sabrina L; Buntzman, Adam S; Young, Ellen F; Vincent, Benjamin G; Hess, Paul R; DVM

    2012-01-01

    Major histocompatibility complex (MHC) class I and MHC class II molecules present short peptides that are derived from endogenous and exogenous proteins, respectively, to cognate T-cell receptors (TCRs) on the surface of T cells. The exquisite specificity with which T cells recognize particular peptide–major-histocompatibility-complex (pMHC) combinations has permitted development of soluble pMHC multimers that bind exclusively to selected T-cell populations. Because the pathogenesis of type 1 diabetes mellitus (T1DM) is driven largely by islet-reactive T-cell activity that causes β-cell death, these reagents are useful tools for studying and, potentially, for treating this disease. When coupled to fluorophores or paramagnetic nanoparticles, pMHC multimers have been used to visualize the expansion and islet invasion of T-cell effectors during diabetogenesis. Administration of pMHC multimers to mice has been shown to modulate T-cell responses by signaling through the TCR or by delivering a toxic moiety that deletes the targeted T cell. In the nonobese diabetic mouse model of T1DM, a pMHC-I tetramer coupled to a potent ribosome-inactivating toxin caused long-term elimination of a specific diabetogenic cluster of differentiation 8+ T-cell population from the pancreatic islets and delayed the onset of diabetes. This review will provide an overview of the development and use of pMHC multimers, particularly in T1DM, and describe the therapeutic promise these reagents have as an antigen-specific means of ameliorating deleterious T-cell responses in this autoimmune disease. PMID:22768881

  10. Factored-matrix representation of distributed fast transforms. Master's thesis

    SciTech Connect

    Bainbridge, R.L.

    1987-03-01

    Parallel implementations of Fast Fourier Transforms (FFTs) and other fast transforms are represented using factored, partitioned matrices. The factored matrix description of a distributed FFT is introduced using a decimation in time (DIT) FFT algorithm suitable for implementation on a distributed-signal processor. The heart of the matrix representation of distributed fast transforms is the use of permutations of an NxN identity matrix to describe the required interprocessor data transfers on the Butterfly Network. The properties of these transfer matrices and the resulting output ordering are discussed in detail. The factored matrix representation is then used to show that the Fast Hartley Transform (FHT) and the Walsh Hadamard Transform (WHT) are supported by the Butterfly Network.

  11. Pion Electromagnetic Form Factor in Virtuality Distribution Formalism

    SciTech Connect

    Radyushkin, Anatoly V.

    2016-01-01

    We discuss two applications of the {\\it Virtuality Distribution Amplitudes} (VDA) formalism developed in our recent papers. We start with an overview of the main properties of the pion distribution amplitude emphasizing the quantitative measures of its width, and possibility to access them through the pion transition form factor studies. We formulate the basic concepts of the VDA approach and introduce the pion {\\it transverse momentum distribution amplitude} (TMDA) which plays, in a covariant Lagrangian formulation, a role similar to that of the pion wave function in the 3-dimensional Hamiltonian light-front approach. We propose simple factorized models for soft TMDAs, and use them to describe existing data on the pion transition form factor, thus fixing the scale determining the size of the transverse-momentum effects. Finally, we apply the VDA approach to the one-gluon exchange contribution for the pion electromagnetic form factor. We observe a very late $Q^2 \\gtrsim 20$ GeV$^2$ onset of transition to the asymptotic pQCD predictions and show that in the $Q^2 \\lesssim 10$ GeV$^2$ region there is essentially no sensitivity to the shape of the pion distribution amplitude. Furthermore, the magnitude of the one-gluon exchange contribution in this region is estimated to be an order of magnitude below the Jefferson Lab data, thus leaving the Feynman mechanism as the only one relevant to the pion electromagnetic form factor behavior for accessible $Q^2$.

  12. Mining airborne particulate size distribution data by positive matrix factorization

    NASA Astrophysics Data System (ADS)

    Zhou, Liming; Kim, Eugene; Hopke, Philip K.; Stanier, Charles; Pandis, Spyros N.

    2005-04-01

    Airborne particulate size distribution data acquired in Pittsburgh from July 2001 to June 2002 were analyzed as a bilinear receptor model solved by positive matrix factorization (PMF). The data were obtained from two scanning mobility particle spectrometers and an aerodynamic particle sampler with a temporal resolution of 15 min. Each sample contained 165 size bins from 0.003 to 2.5 μm. Particle growth periods in nucleation events were identified, and the data in these intervals were excluded from this study so that the size distribution profiles associated with the factors could be regarded as sufficiently constant to satisfy the assumptions of the receptor model. The values for each set of five consecutive size bins were averaged to produce 33 new size intervals. Analyses were made on monthly data sets to ensure that the changes in the size distributions from the source to the receptor site could be regarded as constant. The factors from PMF could be assigned to particle sources by examination of the number size distributions associated with the factors, the time frequency properties of the contribution of each source (Fourier analysis of source contribution values), and the correlations of the contribution values with simultaneous gas phase measurements (O3, NO, NO2, SO2, CO) and particle composition data (sulfate, nitrate, organic carbon/elemental carbon). Seasonal trends and weekday/weekend effects were investigated. Conditional probability function analyses were performed for each source to ascertain the likely directions in which the sources were located. Five factors were separated. Two factors, local traffic and nucleation, are clear sources, but each of the other factors appears to be a mixture of several sources that cannot be further separated.

  13. Unique profile of chicken adiponectin, a predominantly heavy molecular weight multimer, and relationship to visceral adiposity.

    PubMed

    Hendricks, Gilbert L; Hadley, Jill A; Krzysik-Walker, Susan M; Prabhu, K Sandeep; Vasilatos-Younken, Regina; Ramachandran, Ramesh

    2009-07-01

    Adiponectin, a 30-kDa adipokine hormone, circulates as heavy, medium, and light molecular weight isoforms in mammals. Plasma heavy molecular weight (HMW) adiponectin isoform levels are inversely correlated with the incidence of type 2 diabetes in humans. The objectives of the present study were to characterize adiponectin protein and quantify plasma adiponectin levels in chickens, which are naturally hyperglycemic relative to mammals. Using gel filtration column chromatography and Western blot analysis under nonreducing and non-heat-denaturing native conditions, adiponectin in chicken plasma, and adipose tissue is predominantly a multimeric HMW isoform that is larger than 669 kDa mass. Under reducing conditions and heating to 70-100 C, however, a majority of the multimeric adiponectin in chicken plasma and adipose tissue was reduced to oligomeric and/or monomeric forms. Immunoprecipitation and elution under neutral pH preserved the HMW adiponectin multimer, whereas brief exposure to acidic pH led to dissociation of HMW multimer into multiple oligomers. Mass spectrometric analysis of chicken adiponectin revealed the presence of hydroxyproline and differential glycosylation of hydroxylysine residues in the collagenous domain. An enzyme immunoassay was developed and validated for quantifying plasma adiponectin in chickens. Plasma adiponectin levels were found to be significantly lower in 8- compared with 4-wk-old male chickens and inversely related to abdominal fat pad mass. Collectively, our results provide novel evidence that adiponectin in chicken plasma and tissues is predominantly a HMW multimer, suggesting the presence of unique multimerization and stabilization mechanisms in the chicken that favors preponderance of HMW adiponectin over other oligomers. PMID:19299452

  14. Options for Development of Parametric Probability Distributions for Exposure Factors

    EPA Science Inventory

    Users of the Exposure Factors Handbook (EPA/600/P-95/002Fa-Fc) expressed the need to fit distributions to the data in the handbook to assist them when applying probabilistic methods to exposure assessments. The purpose of this document is to fulfill this need. The do...

  15. Directional reflectance factor distributions of a cotton row crop

    NASA Technical Reports Server (NTRS)

    Kimes, D. S.; Newcomb, W. W.; Schutt, J. B.; Pinter, P. J., Jr.; Jackson, R. D.

    1984-01-01

    The directional reflectance factor distribution spanning the entire exitance hemisphere was measured for a cotton row crop (Gossypium barbadense L.) with 39 percent ground cover. Spectral directional radiances were taken in NOAA satellite 7 AVHRR bands 1 and 2 using a three-band radiometer with restricted 12 deg full angle field of view at half peak power points. Polar co-ordinate system plots of directional reflectance factor distributions and three-dimensional computer graphic plots of scattered flux were used to study the dynamics of the directional reflectance factor distribution as a function of spectral band, geometric structure of the scene, solar zenith and azimuth angles, and optical properties of the leaves and soil. The factor distribution of the incomplete row crops was highly polymodal relative to that for complete vegetation canopies. Besides the enhanced reflectance for the antisolar point, a reflectance minimum was observed towards the forwardscatter direction in the principle plane of the sun. Knowledge of the mechanics of the observed dynamics of the data may be used to provide rigorous validation for two- or three-dimensional radiative transfer models, and is important in interpreting aircraft and satellite data where the solar angle varies widely.

  16. Rearrangement of MICU1 multimers for activation of MCU is solely controlled by cytosolic Ca2+

    PubMed Central

    Waldeck-Weiermair, Markus; Malli, Roland; Parichatikanond, Warisara; Gottschalk, Benjamin; Madreiter-Sokolowski, Corina T.; Klec, Christiane; Rost, Rene; Graier, Wolfgang F.

    2015-01-01

    Mitochondrial Ca2+ uptake is a vital process that controls distinct cell and organelle functions. Mitochondrial calcium uptake 1 (MICU1) was identified as key regulator of the mitochondrial Ca2+ uniporter (MCU) that together with the essential MCU regulator (EMRE) forms the mitochondrial Ca2+ channel. However, mechanisms by which MICU1 controls MCU/EMRE activity to tune mitochondrial Ca2+ signals remain ambiguous. Here we established a live-cell FRET approach and demonstrate that elevations of cytosolic Ca2+ rearranges MICU1 multimers with an EC50 of 4.4 μM, resulting in activation of mitochondrial Ca2+ uptake. MICU1 rearrangement essentially requires the EF-hand motifs and strictly correlates with the shape of cytosolic Ca2+ rises. We further show that rearrangements of MICU1 multimers were independent of matrix Ca2+ concentration, mitochondrial membrane potential, and expression levels of MCU and EMRE. Our experiments provide novel details about how MCU/EMRE is regulated by MICU1 and an original approach to investigate MCU/EMRE activation in intact cells. PMID:26489515

  17. Rearrangement of MICU1 multimers for activation of MCU is solely controlled by cytosolic Ca(2.).

    PubMed

    Waldeck-Weiermair, Markus; Malli, Roland; Parichatikanond, Warisara; Gottschalk, Benjamin; Madreiter-Sokolowski, Corina T; Klec, Christiane; Rost, Rene; Graier, Wolfgang F

    2015-01-01

    Mitochondrial Ca(2+) uptake is a vital process that controls distinct cell and organelle functions. Mitochondrial calcium uptake 1 (MICU1) was identified as key regulator of the mitochondrial Ca(2+) uniporter (MCU) that together with the essential MCU regulator (EMRE) forms the mitochondrial Ca(2+) channel. However, mechanisms by which MICU1 controls MCU/EMRE activity to tune mitochondrial Ca(2+) signals remain ambiguous. Here we established a live-cell FRET approach and demonstrate that elevations of cytosolic Ca(2+) rearranges MICU1 multimers with an EC50 of 4.4 μM, resulting in activation of mitochondrial Ca(2+) uptake. MICU1 rearrangement essentially requires the EF-hand motifs and strictly correlates with the shape of cytosolic Ca(2+) rises. We further show that rearrangements of MICU1 multimers were independent of matrix Ca(2+) concentration, mitochondrial membrane potential, and expression levels of MCU and EMRE. Our experiments provide novel details about how MCU/EMRE is regulated by MICU1 and an original approach to investigate MCU/EMRE activation in intact cells. PMID:26489515

  18. Distribution of insulin-like growth factors in condylar hyperplasia.

    PubMed

    Götz, Werner; Lehmann, Tim Sebastian; Appel, Thorsten Robin; Rath-Deschner, Birgit; Dettmeyer, Reinhard; Luder, Hans-Ulrich; Reich, Rudolf H; Jäger, Andreas

    2007-01-01

    Condylar hyperplasia (CH) is a local overgrowth of the condylar process of the temporomandibular joint (TMJ) of unknown etiology. Probably, growth factors like the insulin-like growth factors (IGFs) are involved in its pathogenesis. Specimens from 12 patients were investigated histologically and immunohistochemically to obtain the distribution of the IGFs-I and -II and the IGF1 receptor. The results revealed juvenile and adult subtypes. While generally IGF-II could only be detected weakly, in the juvenile cases strong immunostaining for IGF-I in cartilage and bone supposes an influence on pathological growth processes. PMID:17695990

  19. Factors influencing the effect size distribution of adaptive substitutions

    PubMed Central

    Oakley, Christopher G.; Gould, Billie A.; Schemske, Douglas W.

    2016-01-01

    The distribution of effect sizes of adaptive substitutions has been central to evolutionary biology since the modern synthesis. Early theory proposed that because large-effect mutations have negative pleiotropic consequences, only small-effect mutations contribute to adaptation. More recent theory suggested instead that large-effect mutations could be favoured when populations are far from their adaptive peak. Here we suggest that the distributions of effect sizes are expected to differ among study systems, reflecting the wide variation in evolutionary forces and ecological conditions experienced in nature. These include selection, mutation, genetic drift, gene flow, and other factors such as the degree of pleiotropy, the distance to the phenotypic optimum, whether the optimum is stable or moving, and whether new mutation or standing genetic variation provides the source of adaptive alleles. Our goal is to review how these factors might affect the distribution of effect sizes and to identify new research directions. Until more theory and empirical work is available, we feel that it is premature to make broad generalizations about the effect size distribution of adaptive substitutions important in nature. PMID:27053750

  20. SDS-PAGE/immunoblot detection of Abeta multimers in human cortical tissue homogenates using antigen-epitope retrieval.

    PubMed

    Rosen, Rebecca F; Tomidokoro, Yasushi; Ghiso, Jorge A; Walker, Lary C

    2010-01-01

    The anomalous folding and polymerization of the beta-amyloid (Abeta) peptide is thought to initiate the neurodegenerative cascade in Alzheimer's disease pathogenesis(1). Abeta is predominantly a 40- or 42-amino acid peptide that is prone to self-aggregation into beta-sheet-rich amyloid fibrils that are found in the cores of cerebral senile plaques in Alzheimer's disease. Increasing evidence suggests that low molecular weight, soluble Abeta multimers are more toxic than fibrillar Abeta amyloid(2). The identification and quantification of low- and high-molecular weight multimeric Abeta species in brain tissue is an essential objective in Alzheimer's disease research, and the methods employed also can be applied to the identification and characterization of toxic multimers in other proteopathies(3). Naturally occurring Abeta multimers can be detected by SDS-polyacrylamide gel electrophoresis followed by immunoblotting with Abeta-specific antibodies. However, the separation and detection of multimeric Abeta requires the use of highly concentrated cortical homogenates and antigen retrieval in small pore-size nitrocellulose membranes. Here we describe a technique for the preparation of clarified human cortical homogenates, separation of proteins by SDS-PAGE, and antigen-epitope retrieval/Western blotting with antibody 6E10 to the N-terminal region of the Abeta peptide. Using this protocol, we consistently detect Abeta monomers, dimers, trimers, tetramers, and higher molecular weight multimers in cortical tissue from humans with Alzheimer's pathology. PMID:20418805

  1. Mitochondrial uncoupler carbonyl cyanide M-chlorophenylhydrazone induces the multimer assembly and activity of repair enzyme protein L-isoaspartyl methyltransferase.

    PubMed

    Fanélus, Irvens; Desrosiers, Richard R

    2013-07-01

    The protein L-isoaspartyl methyltransferase (PIMT) repairs damaged aspartyl residues in proteins. It is commonly described as a cytosolic protein highly expressed in brain tissues. Here, we report that PIMT is an active monomeric as well as a multimeric protein in mitochondria isolated from neuroblastoma cells. Upon treatments with mitochondrial uncoupler carbonyl cyanide m-chlorophenylhydrazone (CCCP), PIMT monomers level decreased by half while that of PIMT multimers was higher. Gel electrophoresis under reducing conditions of CCCP-induced PIMT multimers led to PIMT monomers accumulation, indicating that multimers resulted from disulfide-linked PIMT monomers. The antioxidant ascorbic acid significantly lowered CCCP-induced formation of PIMT multimers, suggesting that reactive oxygen species contributed to PIMT multimerization. In addition, the elevation of PIMT multimers catalytic activity upon treatments with CCCP was severely inhibited by the reducing agent dithiothreitol. This indicated that PIMT monomers have lower enzymatic activity following CCCP treatments and that activation of PIMT multimers is essentially dependent on the formation of disulfide-linked monomers of PIMT. Furthermore, the perturbation of mitochondrial function by CCCP promoted the accumulation of damaged aspartyl residues in proteins with high molecular weights. Thus, this study demonstrates the formation of active PIMT multimers associated with mitochondria that could play a key role in repairing damaged proteins accumulating during mitochondrial dysfunction. PMID:23319267

  2. Magnetic microparticle-based multimer detection system for the detection of prion oligomers in sheep

    PubMed Central

    Lim, Kuntaek; Kim, Su Yeon; Lee, Byoungsub; Segarra, Christiane; Kang, Sungmin; Ju, Youngran; Schmerr, Mary Jo; Coste, Joliette; Kim, Sang Yun; Yokoyama, Takashi; An, Seong Soo A

    2015-01-01

    Transmissible spongiform encephalopathies (TSEs) are zoonotic fatal neurodegenerative diseases in animals and humans. TSEs are commonly known as bovine spongiform encephalopathy in cattle, scrapie in sheep and goats, chronic wasting disease in cervids, and Creutzfeldt–Jakob disease in humans. The putative transmissible agents are infectious prion proteins (PrPSc), which are formed by the conversion of the normal prion protein on the glycoprotein cell surface in the presence of other PrPSc. Reports of the transmission of TSEs through blood raised considerable concern about the safety of blood and blood products. To address this issue, many laboratories attempted to develop a sensitive and accurate blood diagnostic test to detect PrPSc. Previously, we reported that, compared to normal controls, the multimer detection system (MDS) was more efficient in detecting PrPSc in infected hamster brain homogenate, mouse plasma spiked with purified PrPSc from scrapie mouse brain, and scrapie-infected hamster plasmas. MDS differentiates prion multimers from the cellular monomer through the multimeric expression of epitopes on prion multimers, in contrast to the monomeric form. In this study, MDS detected PrPSc in plasma samples from scrapie-infected sheep expressing clinical symptoms, demonstrating 100% sensitivity and specificity in these samples. Plasma samples from asymptomatic lambs at the preclinical stage (8-month-old naturally infected offspring of scrapie-infected parents expressing a highly susceptible genotype) tested positive with 50% sensitivity and 100% specificity. In the first of two coded analyses using clinical scrapie-infected sheep and normal healthy samples, MDS successfully identified all but one of the clinical samples with 92% sensitivity and 100% specificity. Similar results were obtained in the second coded analysis using preclinical samples. MDS again successfully identified all but one of the samples with 87% sensitivity and 100% specificity. The

  3. Magnetic microparticle-based multimer detection system for the detection of prion oligomers in sheep.

    PubMed

    Lim, Kuntaek; Kim, Su Yeon; Lee, Byoungsub; Segarra, Christiane; Kang, Sungmin; Ju, Youngran; Schmerr, Mary Jo; Coste, Joliette; Kim, Sang Yun; Yokoyama, Takashi; An, Seong Soo A

    2015-01-01

    Transmissible spongiform encephalopathies (TSEs) are zoonotic fatal neurodegenerative diseases in animals and humans. TSEs are commonly known as bovine spongiform encephalopathy in cattle, scrapie in sheep and goats, chronic wasting disease in cervids, and Creutzfeldt-Jakob disease in humans. The putative transmissible agents are infectious prion proteins (PrP(Sc)), which are formed by the conversion of the normal prion protein on the glycoprotein cell surface in the presence of other PrP(Sc). Reports of the transmission of TSEs through blood raised considerable concern about the safety of blood and blood products. To address this issue, many laboratories attempted to develop a sensitive and accurate blood diagnostic test to detect PrP(Sc). Previously, we reported that, compared to normal controls, the multimer detection system (MDS) was more efficient in detecting PrP(Sc) in infected hamster brain homogenate, mouse plasma spiked with purified PrP(Sc) from scrapie mouse brain, and scrapie-infected hamster plasmas. MDS differentiates prion multimers from the cellular monomer through the multimeric expression of epitopes on prion multimers, in contrast to the monomeric form. In this study, MDS detected PrP(Sc) in plasma samples from scrapie-infected sheep expressing clinical symptoms, demonstrating 100% sensitivity and specificity in these samples. Plasma samples from asymptomatic lambs at the preclinical stage (8-month-old naturally infected offspring of scrapie-infected parents expressing a highly susceptible genotype) tested positive with 50% sensitivity and 100% specificity. In the first of two coded analyses using clinical scrapie-infected sheep and normal healthy samples, MDS successfully identified all but one of the clinical samples with 92% sensitivity and 100% specificity. Similar results were obtained in the second coded analysis using preclinical samples. MDS again successfully identified all but one of the samples with 87% sensitivity and 100

  4. Estimate Soil Erodibility Factors Distribution for Maioli Block

    NASA Astrophysics Data System (ADS)

    Lee, Wen-Ying

    2014-05-01

    The natural conditions in Taiwan are poor. Because of the steep slopes, rushing river and fragile geology, soil erosion turn into a serious problem. Not only undermine the sloping landscape, but also created sediment disaster like that reservoir sedimentation, river obstruction…etc. Therefore, predict and control the amount of soil erosion has become an important research topic. Soil erodibility factor (K) is a quantitative index of distinguish the ability of soil to resist the erosion separation and handling. Taiwan soil erodibility factors have been calculated 280 soil samples' erodibility factors by Wann and Huang (1989) use the Wischmeier and Smith nomorgraph. 221 samples were collected at the Maioli block in Miaoli. The coordinates of every sample point and the land use situations were recorded. The physical properties were analyzed for each sample. Three estimation methods, consist of Kriging, Inverse Distance Weighted (IDW) and Spline, were applied to estimate soil erodibility factors distribution for Maioli block by using 181 points data, and the remaining 40 points for the validation. Then, the SPSS regression analysis was used to comparison of the accuracy of the training data and validation data by three different methods. Then, the best method can be determined. In the future, we can used this method to predict the soil erodibility factors in other areas.

  5. Positional distribution of transcription factor binding sites in Arabidopsis thaliana

    PubMed Central

    Yu, Chun-Ping; Lin, Jinn-Jy; Li, Wen-Hsiung

    2016-01-01

    Binding of a transcription factor (TF) to its DNA binding sites (TFBSs) is a critical step to initiate the transcription of its target genes. It is therefore interesting to know where the TFBSs of a gene are likely to locate in the promoter region. Here we studied the positional distribution of TFBSs in Arabidopsis thaliana, for which many known TFBSs are now available. We developed a method to identify the locations of TFBSs in the promoter sequences of genes in A. thaliana. We found that the distribution is nearly bell-shaped with a peak at 50 base pairs (bp) upstream of the transcription start site (TSS) and 86% of the TFBSs are in the region from −1,000 bp to +200 bp with respect to the TSS. Our distribution was supported by chromatin immunoprecipitation sequencing and microarray data and DNase I hypersensitive site sequencing data. When TF families were considered separately, differences in positional preference were observed between TF families. Our study of the positional distribution of TFBSs seems to be the first in a plant. PMID:27117388

  6. Improved load distribution in parallel sparse Cholesky factorization

    NASA Technical Reports Server (NTRS)

    Rothberg, Edward; Schreiber, Robert

    1994-01-01

    Compared to the customary column-oriented approaches, block-oriented, distributed-memory sparse Cholesky factorization benefits from an asymptotic reduction in interprocessor communication volume and an asymptotic increase in the amount of concurrency that is exposed in the problem. Unfortunately, block-oriented approaches (specifically, the block fan-out method) have suffered from poor balance of the computational load. As a result, achieved performance can be quite low. This paper investigates the reasons for this load imbalance and proposes simple block mapping heuristics that dramatically improve it. The result is a roughly 20% increase in realized parallel factorization performance, as demonstrated by performance results from an Intel Paragon system. We have achieved performance of nearly 3.2 billion floating point operations per second with this technique on a 196-node Paragon system.

  7. Dynamics of directional reflectance factor distributions for vegetation canopies

    NASA Technical Reports Server (NTRS)

    Kimes, D. S.

    1983-01-01

    Directional reflectance factors that span the entire exitance hemisphere are collected on the ground for a variety of homogeneous vegetation canopies and bare soils. NOAA 6/7 AVHRR bands 1 (0.58-0.68 micron) and 2 (0.73-1.1 microns) are used. When possible, geometric measurements of leaf orientation distributions are taken simultaneously with each spectral measurement. Other supporting structural and optical measurements are made. These data sets are taken at various times of the day for each cover type. These unique sets, together with pertinent data in the literature, are used to investigate the dynamics of the directional reflectance factor distribution as a function of the geometric structure of the scene, solar zenith angle, and optical properties of the scene components (leaves and soil). For complete homogeneous vegetation canopies, the principal trend observed at all sun angles and spectral bands is a minimum reflectance near nadir and increasing reflectance with increasing off-nadir view angle for all azimuth directions.

  8. The distribution of hospital nurses and associated factors.

    PubMed

    Sakata, Yayoi; Morioka, Noriko; Nakamura, Fumiaki; Toyokawa, Satoshi; Kobayashi, Yasuki

    2016-01-01

    Objectives With the increasing aging population in Japan, the demand for medical and long-term care is expected to grow. Consequently, it is important to secure sufficient nursing personnel for medical care facilities. Careful monitoring of the allocation of nurses is crucial for providing services that match the needs of the population. However, few studies have examined the distribution of nurses by the type of facility in which they work or identified any associated factors. The objectives of this study are to examine trends in the distribution of nurses working in hospitals and to identify any associated factors such as policy changes, local socioeconomic characteristics, and nurse supply-and-demand-related factors.Methods We conducted an ecological study using public survey data from 2002 to 2011. We focused on 274 secondary medical areas (SMAs) in 38 prefectures from which we could obtain continuous data over the study period. We calculated the number of hospital nurses per 100,000 of the population in each SMA as well as the Gini coefficient. The explained variable was the number of hospital nurses per 100,000 of the population. We employed the following explanatory variables: SMA population, aging population ratio, population density category, per capita income, region, number of nursing school graduates, and nurse wages offered during the previous year. We then examined the association by applying multilevel analysis.Results The number of hospital nurses per 100,000 of the population in the SMAs increased during the period. The Gini coefficient decreased as a general trend but increased in 2007 and 2008. After adjusting for the SMA population and its increase, depending on the year, the number of hospital nurses was positively correlated with higher income per capita, higher aging population ratio, regions other than Kanto, higher number of nursing school graduates, and higher previous-year wages.Conclusion Although the differences in the numbers

  9. Distribution of corticotropin-releasing factor receptors in primate brain

    SciTech Connect

    Millan, M.A.; Jacobowitz, D.M.; Hauger, R.L.; Catt, K.J.; Aguilera, G.

    1986-03-01

    The distribution and properties of receptors for corticotropin-releasing factor (CRF) were analyzed in the brain of cynomolgus monkeys. Binding of (/sup 125/I)tyrosine-labeled ovine CRF to frontal cortex and amygdala membrane-rich fractions was saturable, specific, and time- and temperature-dependent, reaching equilibrium in 30 min at 23/sup 0/C. Scatchard analysis of the binding data indicated one class of high-affinity sites with a K/sub d/ of 1 nM and a concentration of 125 fmol/mg. As in the rat pituitary and brain, CRF receptors in monkey cerebral cortex and amygdala were coupled to adenylate cyclase. Autoradiographic analysis of specific CRF binding in brain sections revealed that the receptors were widely distributed in the cerebral cortex and limbic system. Receptor density was highest in the pars tuberalis of the pituitary and throughout the cerebral cortex, specifically in the prefrontal, frontal, orbital, cingulate, insular, and temporal areas, and in the cerebellar cortex. A low binding density was present in the superior colliculus, locus coeruleus, substantia gelatinosa, preoptic area, septal area, and bed nucleus of the stria terminalis. These data demonstrate that receptors for CRF are present within the primate brain at areas related to the central control of visceral function and behavior, suggesting that brain CRF may serve as a neurotransmitter in the coordination of endocrine and neural mechanisms involved in the response to stress.

  10. Directional reflectance factor distributions for cover types of Northern Africa

    NASA Technical Reports Server (NTRS)

    Kimes, D. S.; Newcomb, W. W.; Tucker, C. J.; Zonneveld, I. S.; Van Wijngaarden, W.

    1985-01-01

    Directional reflectance factors that spanned the entire exitance hemisphere were collected on the ground throughout the morning period for common cover types in Tunisia, Africa. NOAA 7/8 AVHRR bands 1(0.58-0.68 micron) and 2 (0.7301.1 micron) were used in data collection. The cover types reported were a plowed field, annual grassland, steppe grassland, hard wheat, salt plain, and irrigated wheat. Several of these cover types had geometric structures that are extreme as compared to those reported in the literature. Comparisons were made between the dynamics of the observed reflectance distributions and those reported in the literature. It was found that the dynamics of the measured data could be explained by a combination of soil and vegetation scattering components. The data and analysis further validated physical principles that cause the reflectance distribution dynamics as proposed by field and simulation studies in the literature. Finally, the normalized difference transformation (Band 2 - Band 1)/(Band 1 + Band 2), which is useful in monitoring vegetation cover, generally decreased the variation in signal with changing view angle. However, several exceptions were noted.

  11. Antibody Stabilization of Peptide–MHC Multimers Reveals Functional T Cells Bearing Extremely Low-Affinity TCRs

    PubMed Central

    Tungatt, Katie; Bianchi, Valentina; Crowther, Michael D.; Powell, Wendy E.; Schauenburg, Andrea J.; Trimby, Andrew; Donia, Marco; Miles, John J.; Holland, Christopher J.; Cole, David K.; Godkin, Andrew J.; Peakman, Mark; Straten, Per Thor; Svane, Inge Marie; Dolton, Garry

    2015-01-01

    Fluorochrome-conjugated peptide–MHC (pMHC) multimers are commonly used in combination with flow cytometry for direct ex vivo visualization and characterization of Ag-specific T cells, but these reagents can fail to stain cells when TCR affinity and/or TCR cell-surface density are low. pMHC multimer staining of tumor-specific, autoimmune, or MHC class II–restricted T cells can be particularly challenging, as these T cells tend to express relatively low-affinity TCRs. In this study, we attempted to improve staining using anti-fluorochrome unconjugated primary Abs followed by secondary staining with anti-Ab fluorochrome-conjugated Abs to amplify fluorescence intensity. Unexpectedly, we found that the simple addition of an anti-fluorochrome unconjugated Ab during staining resulted in considerably improved fluorescence intensity with both pMHC tetramers and dextramers and with PE-, allophycocyanin-, or FITC-based reagents. Importantly, when combined with protein kinase inhibitor treatment, Ab stabilization allowed pMHC tetramer staining of T cells even when the cognate TCR–pMHC affinity was extremely low (KD >1 mM) and produced the best results that we have observed to date. We find that this inexpensive addition to pMHC multimer staining protocols also allows improved recovery of cells that have recently been exposed to Ag, improvements in the recovery of self-specific T cells from PBMCs or whole-blood samples, and the use of less reagent during staining. In summary, Ab stabilization of pMHC multimers during T cell staining extends the range of TCR affinities that can be detected, yields considerably enhanced staining intensities, and is compatible with using reduced amounts of these expensive reagents. PMID:25452566

  12. Proximate and landscape factors influence grassland bird distributions

    USGS Publications Warehouse

    Cunningham, M.A.; Johnson, D.H.

    2006-01-01

    Ecologists increasingly recognize that birds can respond to features well beyond their normal areas of activity, but little is known about the relative importance of landscapes and proximate factors or about the scales of landscapes that influence bird distributions. We examined the influences of tree cover at both proximate and landscape scales on grassland birds, a group of birds of high conservation concern, in the Sheyenne National Grassland in North Dakota, USA. The Grassland contains a diverse array of grassland and woodland habitats. We surveyed breeding birds on 2015 100 m long transect segments during 2002 and 2003. We modeled the occurrence of 19 species in relation to habitat features (percentages of grassland, woodland, shrubland, and wetland) within each 100-m segment and to tree cover within 200-1600 m of the segment. We used information-theoretic statistical methods to compare models and variables. At the proximate scales, tree cover was the most important variable, having negative influences on 13 species and positive influences on two species. In a comparison of multiple scales, models with only proximate variables were adequate for some species, but models combining proximate with landscape information were best for 17 of 19 species. Landscape-only models were rarely competitive. Combined models at the largest scales (800-1600 m) were best for 12 of 19 species. Seven species had best models including 1600-m landscapes plus proximate factors in at least one year. These were Wilson's Phalarope (Phalaropus tricolor), Sedge Wren (Cistothorus platensis), Field Sparrow (Spizella pusilla), Grasshopper Sparrow (Ammodramus savannarum), Bobolink (Dolychonix oryzivorus), Red-winged Blackbird (Agelaius phoeniceus), and Brown-headed Cowbird (Molothrus ater). These seven are small-bodied species; thus larger-bodied species do not necessarily respond most to the largest landscapes. Our findings suggest that birds respond to habitat features at a variety of

  13. Proximate and landscape factors influence grassland bird distributions.

    PubMed

    Cunningham, Mary Ann; Johnson, Douglas H

    2006-06-01

    Ecologists increasingly recognize that birds can respond to features well beyond their normal areas of activity, but little is known about the relative importance of landscapes and proximate factors or about the scales of landscapes that influence bird distributions. We examined the influences of tree cover at both proximate and landscape scales on grassland birds, a group of birds of high conservation concern, in the Sheyenne National Grassland in North Dakota, USA. The Grassland contains a diverse array of grassland and woodland habitats. We surveyed breeding birds on 2015 100 m long transect segments during 2002 and 2003. We modeled the occurrence of 19 species in relation to habitat features (percentages of grassland, woodland, shrubland, and wetland) within each 100-m segment and to tree cover within 200-1600 m of the segment. We used information-theoretic statistical methods to compare models and variables. At the proximate scales, tree cover was the most important variable, having negative influences on 13 species and positive influences on two species. In a comparison of multiple scales, models with only proximate variables were adequate for some species, but models combining proximate with landscape information were best for 17 of 19 species. Landscape-only models were rarely competitive. Combined models at the largest scales (800-1600 m) were best for 12 of 19 species. Seven species had best models including 1600-m landscapes plus proximate factors in at least one year. These were Wilson's Phalarope (Phalaropus tricolor), Sedge Wren (Cistothorus platensis), Field Sparrow (Spizella pusilla), Grasshopper Sparrow (Ammodramus savannarum), Bobolink (Dolychonix oryzivorus), Red-winged Blackbird (Agelaius phoeniceus), and Brown-headed Cowbird (Molothrus ater). These seven are small-bodied species; thus larger-bodied species do not necessarily respond most to the largest landscapes. Our findings suggest that birds respond to habitat features at a variety of

  14. Behavioral factors influencing spatial distributions of fish in contaminated environments

    SciTech Connect

    Little, E.E.; DeLonay, A.J.; Lipton, J.

    1994-12-31

    In addition to contaminant preference/avoidance responses, contaminant-induced behavioral factors can also influence the spatial distribution of fish. The seaward migrations of smolting anadromous salmonids, can be disrupted by a variety of contaminants, including metals such as copper. This disruption can be reflected in a delay in this normal loss of positive rheotaxis, as fish orient down stream. In estuaries, the fish may fail to show preferences for salt water as well as inhibited physiological adaptations to saltwater. Competitive interactions can also be responsible for the loss of population. Brown trout, for example, appear to be more tolerant of exposure to many contaminants than native fishes, and may also be more aggressive in their interaction with native species. Thus, native fishes in marginal habitats may be driven out by brown trout. Finally predator-prey interactions may play a role in the diminishing native fish populations through increased predation-induced mortality caused by impaired anti-predator defenses. Uniform tests or protocols are required to provide reliable, reproducible results, necessary for regulatory action. Discussion will focus on issues related to generation and establishment of consensus guidelines to encourage the application of behavior in contaminant assessment and application in measures of environmental injury.

  15. Mixture Factor Analysis for Approximating a Nonnormally Distributed Continuous Latent Factor with Continuous and Dichotomous Observed Variables

    ERIC Educational Resources Information Center

    Wall, Melanie M.; Guo, Jia; Amemiya, Yasuo

    2012-01-01

    Mixture factor analysis is examined as a means of flexibly estimating nonnormally distributed continuous latent factors in the presence of both continuous and dichotomous observed variables. A simulation study compares mixture factor analysis with normal maximum likelihood (ML) latent factor modeling. Different results emerge for continuous versus…

  16. Seed-Specific Expression of Spider Silk Protein Multimers Causes Long-Term Stability.

    PubMed

    Weichert, Nicola; Hauptmann, Valeska; Helmold, Christine; Conrad, Udo

    2016-01-01

    Seeds enable plants to germinate and to grow in situations of limited availability of nutrients. The stable storage of different seed proteins is a remarkable presumption for successful germination and growth. These strategies have been adapted and used in several molecular farming projects. In this study, we explore the benefits of seed-based expression to produce the high molecular weight spider silk protein FLAG using intein-based trans-splicing. Multimers larger than 460 kDa in size are routinely produced, which is above the native size of the FLAG protein. The storage of seeds for 8 weeks and 1 year at an ambient temperature of 15°C does not influence the accumulation level. Even the extended storage time does not influence the typical pattern of multimerized bands. These results show that seeds are the method of choice for stable accumulation of products of complex transgenes and have the capability for long-term storage at moderate conditions, an important feature for the development of suitable downstream processes. PMID:26858734

  17. Assembly and function of AsGlu2 fibrillar multimer of oat beta-glucosidase.

    PubMed

    Kwak, Su-Nam; Kim, Sang-Yeob; Choi, Sa-Ra; Kim, In-Soo

    2009-03-01

    Oat beta-glucosidase in plastid exists as a long fibrillar structure of AsGlu1 homomultimer (type I) and heteromultimer of AsGlu1 and AsGlu2 (type II). In spite of the high amino acid sequence homology of AsGlu1 and AsGlu2, AsGlu1 assembles into the fibrillar multimers but AsGlu2 forms a dimer when expressed in E. coli. A swapping analysis of AsGlu2 cDNA with AsGlu1 cDNA indicated that the C-terminal segment of AsGlu1 was critical for the fibrillar multimerization. A single substitution of glutamic acid-495 of AsGlu2 in the C-terminal region with lysine, an AsGlu1 counterpart amino acid for the glutamic acid-495, assembled the AsGlu2 into fibrillar homomultimers. The mutant AsGlu2 homomultimer was highly stable and had relatively faster electric mobility in native gel than the AsGlu1 homomultimer. Multimerization increased enzyme affinity to substrates. PMID:19100871

  18. Seed-Specific Expression of Spider Silk Protein Multimers Causes Long-Term Stability

    PubMed Central

    Weichert, Nicola; Hauptmann, Valeska; Helmold, Christine; Conrad, Udo

    2016-01-01

    Seeds enable plants to germinate and to grow in situations of limited availability of nutrients. The stable storage of different seed proteins is a remarkable presumption for successful germination and growth. These strategies have been adapted and used in several molecular farming projects. In this study, we explore the benefits of seed-based expression to produce the high molecular weight spider silk protein FLAG using intein-based trans-splicing. Multimers larger than 460 kDa in size are routinely produced, which is above the native size of the FLAG protein. The storage of seeds for 8 weeks and 1 year at an ambient temperature of 15°C does not influence the accumulation level. Even the extended storage time does not influence the typical pattern of multimerized bands. These results show that seeds are the method of choice for stable accumulation of products of complex transgenes and have the capability for long-term storage at moderate conditions, an important feature for the development of suitable downstream processes. PMID:26858734

  19. Oligomerization of bovine ribonuclease A: structural and functional features of its multimers.

    PubMed Central

    Libonati, Massimo; Gotte, Giovanni

    2004-01-01

    Bovine pancreatic RNase A (ribonuclease A) aggregates to form various types of catalytically active oligomers during lyophilization from aqueous acetic acid solutions. Each oligomeric species is present in at least two conformational isomers. The structures of two dimers and one of the two trimers have been solved, while plausible models have been proposed for the structures of a second trimer and two tetrameric conformers. In this review, these structures, as well as the general conditions for RNase A oligomerization, based on the well known 3D (three-dimensional) domain-swapping mechanism, are described and discussed. Attention is also focused on some functional properties of the RNase A oligomers. Their enzymic activities, particularly their ability to degrade double-stranded RNAs and polyadenylate, are summarized and discussed. The same is true for the remarkable antitumour activity of the oligomers, displayed in vitro and in vivo, in contrast with monomeric RNase A, which lacks these activities. The RNase A multimers also show an aspermatogenic action, but lack any detectable embryotoxicity. The fact that both activity against double-stranded RNA and the antitumour action increase with the size of the oligomer suggests that these activities may share a common structural requirement, such as a high number or density of positive charges present on the RNase A oligomers. PMID:15104538

  20. Subcellular Distribution of NTL Transcription Factors in Arabidopsis thaliana.

    PubMed

    Liang, Mingwei; Li, Hongjuan; Zhou, Fang; Li, Huiyong; Liu, Jin; Hao, Yi; Wang, Yingdian; Zhao, Heping; Han, Shengcheng

    2015-10-01

    NAC with a transmembrane (TM) motif1-like (NTL) transcription factors, containing three regions: the N-terminal NAC domain (ND), the middle regulation region (RR), and the C-terminal TM domain, belong to the tail-anchored proteins. Although these NTLs play numerous essential roles in plants, their subcellular distribution and the mechanism of translocation into the nucleus (NU) remain unclear. In this study, we found that most of the full-length NTLs were localized in the endoplasmic reticulum (ER), with the exception of NTL11 and NTL5, which were restricted to the NU. Furthermore, we found that NTL11 contains a TM domain, whereas NTL5 does not. The ND of all of the NTLs was responsible for nuclear localization in plants. After truncation of the TM domain, NTL8_NR, NTL10_NR and NTL13_NR localized in the cytoplasm (CT) and NU, and other NTL_NRs were only localized in the NU, suggesting that the RR of NTL8, NTL10 and NTL13 contains some inhibitory region to mask the nuclear localization signal sequence in the ND domain and permit their diffusion between CT and NU. Furthermore, the N-terminus of NTL11 was translocated to the NU, but the C-terminus was degraded in Arabidopsis mesophyll protoplasts. The chimeric construct of NTL11_ND with NTL10_RR and TM domain (11ND-10RT) was localized exclusively in the ER, and not in the NU. However, 10ND-11RT was found mainly in the NU. Our results indicated that the TM domain is essential for NTL targeting the ER and the N-terminal fragment, including ND and RR, is translocated into the NU after activation through proteolytic cleavage events upon stimulation by internal and external environmental signals. PMID:26201836

  1. The UV index: definition, distribution and factors affecting it.

    PubMed

    Fioletov, Vitali; Kerr, James B; Fergusson, Angus

    2010-01-01

    The UV Index was introduced in Canada in 1992 in response to growing concerns about the potential increase of ultraviolet (UV) radiation due to ozone depletion. The index was adopted as a standard indicator of UV levels by the World Meteorological Organization and World Health Organization in 1994. This survey article gives an overview of the UV Index and the main features of its geographical distribution. UV index values are determined from measurements made by ground-based spectrometers, broad-band filter radiometers and multi-filter radiometers. Radiative transfer models are used to estimate UV Index values from other types of geophysical observations, primarily column ozone and cloud thickness. UV Index values can also be retrieved from satellite measurements of atmospheric ozone and cloud cover. Forecasts of UV Index values are now widely available and are intended to be used by the public as a guide to avoid excessive exposure to UV radiation. Over the US and Canada, mean noontime UV Index values in summer range from 1.5 in the Arctic to 11.5 over southern Texas and can be as high as 20 at high elevations in Hawaii. The UV Index is also often used to quantify UV levels in studies investigating the impact of UV on other biological and photochemical processes. Factors affecting the UV Index, such as the sun elevation, total amount of ozone in the atmosphere, cloud cover, reflection from snow and local pollution, are also discussed. Since its introduction in 1992, the UV Index has become a widely used parameter to characterize solar UV. Information about it can be useful for helping people avoid excessive levels of UV radiation. PMID:21033538

  2. A Benchmarking Analysis for Five Radionuclide Vadose Zone Models (Chain, Multimed{_}DP, Fectuz, Hydrus, and Chain 2D) in Soil Screening Level Calculations

    SciTech Connect

    Chen, J-S.; Drake, R.; Lin, Z.; Jewett, D. G.

    2002-02-26

    Five vadose zone models with different degrees of complexity (CHAIN, MULTIMED{_}DP, FECTUZ, HYDRUS, and CHAIN 2D) were selected for use in radionuclide soil screening level (SSL) calculations. A benchmarking analysis between the models was conducted for a radionuclide ({sup 99}Tc) release scenario at the Las Cruces Trench Site in New Mexico. Sensitivity of three model outputs to the input parameters were evaluated and compared among the models. The three outputs were peak contaminant concentrations, time to peak concentrations at the water table, and time to exceed the contaminants maximum critical level at a representative receptor well. Model parameters investigated include soil properties such as bulk density, water content, soil water retention parameters and hydraulic conductivity. Chemical properties examined include distribution coefficient, radionuclide half-life, dispersion coefficient, and molecular diffusion. Other soil characteristics, such as recharge rate, also were examined. Model sensitivity was quantified in the form of sensitivity and relative sensitivity coefficients. Relative sensitivities were used to compare the sensitivities of different parameters. The analysis indicates that soil water content, recharge rate, saturated soil water content, and soil retention parameter, {beta}, have a great influence on model outputs. In general, the results of sensitivities and relative sensitivities using five models are similar for a specific scenario. Slight differences were observed in predicted peak contaminant concentrations due to different mathematical treatment among models. The results of benchmarking and sensitivity analysis would facilitate the model selection and application of the model in SSL calculations.

  3. Purification of α-synuclein from human brain reveals an instability of endogenous multimers as the protein approaches purity.

    PubMed

    Luth, Eric S; Bartels, Tim; Dettmer, Ulf; Kim, Nora C; Selkoe, Dennis J

    2015-01-20

    Despite two decades of research, the structure-function relationships of endogenous, physiological forms of α-synuclein (αSyn) are not well understood. Most in vitro studies of this Parkinson's disease-related protein have focused on recombinant αSyn that is unfolded and monomeric, assuming that this represents its state in the normal human brain. Recently, we have provided evidence that αSyn exists in considerable part in neurons, erythrocytes, and other cells as a metastable multimer that principally sizes as a tetramer. In contrast to recombinant αSyn, physiological tetramers purified from human erythrocytes have substantial α-helical content and resist pathological aggregation into β-sheet rich fibers. Here, we report the first method to fully purify soluble αSyn from the most relevant source, human brain. We describe protocols that purify αSyn to homogeneity from nondiseased human cortex using ammonium sulfate precipitation, gel filtration, and ion exchange, hydrophobic interaction, and affinity chromatographies. Cross-linking of the starting material and the partially purified chromatographic fractions revealed abundant αSyn multimers, including apparent tetramers, but these were destabilized in large part to monomers during the final purification step. The method also fully purified the homologue β-synuclein, with a similar outcome. Circular dichroism spectroscopy showed that purified, brain-derived αSyn can display more helical content than the recombinant protein, but this result varied. Collectively, our data suggest that purifying αSyn to homogeneity destabilizes native, α-helix-rich multimers that exist in intact and partially purified brain samples. This finding suggests existence of a stabilizing cofactor (e.g., a small lipid) present inside neurons that is lost during final purification. PMID:25490121

  4. Increased Length of Long Terminal Repeats Inhibits Ty1 Transposition and Leads to the Formation of Tandem Multimers

    PubMed Central

    Lauermann, V.; Hermankova, M.; Boeke, J. D.

    1997-01-01

    The Ty1 retrotransposon of Saccharomyces cerevisiae is bounded by long-terminal repeats (LTRs). We have constructed a variety of Ty1 elements in which the LTR length has been increased from the normal length of 334 bp to >2 kb. Although small insertions in the LTR have minimal effects on transposition frequency, larger insertions dramatically reduce it. Nevertheless, elements with long LTRs are incorporated into the genome at a low frequency. Most of these rare insertion events represent Ty1 tandem (head to tail) multimers. PMID:9093846

  5. Knife mill operating factors effect on switchgrass particle size distributions

    SciTech Connect

    Bitra, V.S.P.; Womac, A.R.; Yang, Y.T.; Igathinathane, C.; Miu, P.I; Chevanan, Nehru; Sokhansanj, Shahabaddine

    2009-06-01

    Biomass particle size impacts handling, storage, conversion, and dust control systems. Switchgrass (Panicum virgatum L.) particle size distributions created by a knife mill were determined for integral classifying screen sizes from 12.7 to 50.8 mm, operating speeds from 250 to 500 rpm, and mass input rates from 2 to 11 kg/min. Particle distributions were classified with standardized sieves for forage analysis that included horizontal sieving motion with machined-aluminum sieves of thickness proportional to sieve opening dimensions. Then, a wide range of analytical descriptors were examined to mathematically represent the range of particle sizes in the distributions. Correlation coefficient of geometric mean length with knife mill screen size, feed rate, and speed were 0.872, 0.349, and 0.037, respectively. Hence, knife mill screen size largely determined particle size of switchgrass chop. Feed rate had an unexpected influence on particle size, though to a lesser degree than screen size. The Rosin Rammler function fit the chopped switchgrass size distribution data with an R2 > 0.982. Mass relative span was greater than 1, which indicated a wide distribution of particle sizes. Uniformity coefficient was more than 4.0, which indicated a large assortment of particles and also represented a well-graded particle size distribution. Knife mill chopping of switchgrass produced strongly fine skewed mesokurtic particles with 12.7 25.4 mm screens and fine skewed mesokurtic particles with 50.8 mm screen. Results of this extensive analysis of particle sizes can be applied to selection of knife mill operating parameters to produce a particular size of switchgrass chop, and will serve as a guide for relations among the various analytic descriptors of biomass particle distributions.

  6. Factors Influencing the Interstate Distribution of Human Capital.

    ERIC Educational Resources Information Center

    Mu'min, Ridgely A.

    The interstate distribution of defense contract awards may both influence and be influenced by regional differences in educational attainment levels. Data from the 1980 census indicate that the level of educational attainment of adult workers was lowest in Kentucky and highest in Alaska. Statistical analysis of the relationships between this…

  7. 25 CFR 170.223 - What is the Relative Need Distribution Factor (RNDF)?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false What is the Relative Need Distribution Factor (RNDF)? 170.223 Section 170.223 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Indian Reservation Roads Program Funding Relative Need Distribution Factor §...

  8. 25 CFR 170.202 - Does the Relative Need Distribution Factor allocate funding among tribes?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Does the Relative Need Distribution Factor allocate... LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Indian Reservation Roads Program Funding Tribal Transportation Allocation Methodology (ttam) § 170.202 Does the Relative Need Distribution Factor...

  9. 25 CFR 170.202 - Does the Relative Need Distribution Factor allocate funding among tribes?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Does the Relative Need Distribution Factor allocate... LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Indian Reservation Roads Program Funding Tribal Transportation Allocation Methodology (ttam) § 170.202 Does the Relative Need Distribution Factor...

  10. 25 CFR 170.223 - What is the Relative Need Distribution Factor (RNDF)?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false What is the Relative Need Distribution Factor (RNDF)? 170.223 Section 170.223 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Indian Reservation Roads Program Funding Relative Need Distribution Factor §...

  11. 40 CFR Table W - 7 of Subpart W-Default Methane Emission Factors for Natural Gas Distribution

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Emission Factors for Natural Gas Distribution W Table W Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Petroleum and Natural Gas... for Natural Gas Distribution Natural gas distribution Emission factor (scf/hour/component)...

  12. The global distribution of risk factors by poverty level.

    PubMed Central

    Blakely, Tony; Hales, Simon; Kieft, Charlotte; Wilson, Nick; Woodward, Alistair

    2005-01-01

    OBJECTIVE: To estimate the individual-level association of income poverty with being underweight, using tobacco, drinking alcohol, having access only to unsafe water and sanitation, being exposed to indoor air pollution and being obese. METHODS: Using survey data for as many countries as possible, we estimated the relative risk association between income or assets and risk factors at the individual level within 11 medium- and low-income subregions of WHO. WHO and The World Bank data on the prevalence of risk factors and income poverty (defined as living on < US$ 1.00 per day, US$ 1-2.00 per day and > US$ 2.00 per day) were analysed to impute the association between poverty and risk factors for each subregion. The possible effect of poverty reduction on the prevalence of risk factors was estimated using population-attributable risk percentages. FINDINGS: There were strong associations between poverty and malnutrition among children, having access only to unsafe water and sanitation, and being exposed to indoor air pollution within each subregion (relative risks were twofold to threefold greater for those living on < US$ 1.00 per day compared with those living on > US$ 2.00 per day). Associations between poverty and obesity, tobacco use and alcohol use varied across subregions. If everyone living on < US$ 2.00 per day had the risk factor profile of those living on > US$ 2.00 per day, 51% of exposures to unimproved water and sanitation could be avoided as could 37% of malnutrition among children and 38% of exposure to indoor air pollution. The more realistic, but still challenging, Millennium Development Goal of halving the number of people living on < US$ 1.00 per day would achieve much smaller reductions. CONCLUSION: To achieve large gains in global health requires both poverty eradication and public health action. The methods used in this study may be useful for monitoring pro-equity progress towards Millennium Development Goals. PMID:15744404

  13. Factors controlling the regional distribution of vanadium in ground water

    USGS Publications Warehouse

    Wright, Michael T.; Belitz, Kenneth

    2010-01-01

    Although the ingestion of vanadium (V) in drinking water may have possible adverse health effects, there have been relatively few studies of V in groundwater. Given the importance of groundwater as a source of drinking water in many areas of the world, this study examines the potential sources and geochemical processes that control the distribution of V in groundwater on a regional scale. Potential sources of V to groundwater include dissolution of V rich rocks, and waste streams from industrial processes. Geochemical processes such as adsorption/desorption, precipitation/dissolution, and chemical transformations control V concentrations in groundwater. Based on thermodynamic data and laboratory studies, V concentrations are expected to be highest in samples collected from oxic and alkaline groundwater. However, the extent to which thermodynamic data and laboratory results apply to the actual distribution of V in groundwater is not well understood. More than 8400 groundwater samples collected in California were used in this study. Of these samples, high (> or = 50 μg/L) and moderate (25 to 49 μg/L) V concentrations were most frequently detected in regions where both source rock and favorable geochemical conditions occurred. The distribution of V concentrations in groundwater samples suggests that significant sources of V are mafic and andesitic rock. Anthropogenic activities do not appear to be a significant contributor of V to groundwater in this study. High V concentrations in groundwater samples analyzed in this study were almost always associated with oxic and alkaline groundwater conditions, which is consistent with predictions based on thermodynamic data.

  14. Multiple birth risk factors and the distribution of handedness.

    PubMed

    Hicks, R A; Elliott, D; Garbesi, L; Martin, S

    1979-03-01

    In this study, we attempted to maximize the likelihood of replicating Bakan's (1971, 1977a) observations that left-handedness was more probable in college students who were the progeny of "high-risk" births. To do this, the relationships between handedness and a combination of factors known to be associated with birth risk were computed. The observed relationships proved to be trivial and thus the validity of Bakan's hypothesis was questionned. PMID:571779

  15. A BENCHMARKING ANALYSIS FOR FIVE RADIONUCLIDE VADOSE ZONE MODELS (CHAIN, MULTIMED_DP, FECTUZ, HYDRUS, AND CHAIN 2D) IN SOIL SCREENING LEVEL CALCULATIONS

    EPA Science Inventory

    Five radionuclide vadose zone models with different degrees of complexity (CHAIN, MULTIMED_DP, FECTUZ, HYDRUS, and CHAIN 2D) were selected for use in soil screening level (SSL) calculations. A benchmarking analysis between the models was conducted for a radionuclide (99Tc) rele...

  16. Reversible HLA multimers (Streptamers) for the isolation of human cytotoxic T lymphocytes functionally active against tumor- and virus-derived antigens.

    PubMed

    Neudorfer, Julia; Schmidt, Burkhard; Huster, Katharina M; Anderl, Florian; Schiemann, Matthias; Holzapfel, Gerd; Schmidt, Thomas; Germeroth, Lothar; Wagner, Hermann; Peschel, Christian; Busch, Dirk H; Bernhard, Helga

    2007-03-30

    The development of MHC/peptide multimers has facilitated the visualization and purification of antigen-specific T cells. However, the persistence of multimers leads to prolonged T cell receptor signaling and subsequently to altered T-cell function. We have recently developed a new type of MHC/peptide multimers, which can be dissociated from the T cell. Herein, we have generated and tested for the first time reversible HLA/peptide multimers, termed Streptamers, for the isolation of human T cells. The Streptamer technique demonstrates the specificity and sensitivity of conventional HLA/peptide tetramers with regards to the sorting of human T lymphocytes. This is shown for T cells directed against immunogenic peptides derived from viral and tumor-associated antigens. We show that antigen-specific cytotoxic T cells remain functionally active following Streptamer dissociation, whereas lytic function and proliferation of the T cells is impaired in the presence of conventional tetramers. These novel HLA/peptide Streptamer reagents allow the isolation of antigen-specific T cells with preserved function and, therefore, facilitate the development of adoptive T cell transfer regimens for the treatment of patients with cancer or infectious diseases. PMID:17306825

  17. [Distribution and influence factors of Anammox bacteria in sewage treatment systems].

    PubMed

    Zheng, Bingyu; Peng, Yongzhen; Zhang, Liang; Yang, Anming; Zhang, Shujun

    2014-12-01

    Nitrogen removal techniques based on Anammox process are developing rapidly these years. The distribution and diversity of Anammox have become important research directions. A variety of Anammox have been detected till now, of which only Kuenenia and Brocadia are often detected in wastewater treatment systems. In addition, in a single niche there is only one type of Anammox bacteria. However, the distribution mechanism and transformation of Anammox bacteria in different niches are still ambiguous. Therefore, the distribution of Anammox in various conditions was summarized and analyzed in this article. And the key factors influencing the distribution of Anammox were concluded, including substrate concentration and the specific growth rate, sludge properties and microbial niche, the joint action and influence of multiple factors. The engineering significance research on the distribution and influencing factors of Anammox bacteria in the sewage system and proposed research prospects were expounded. PMID:26016371

  18. ZOSTERA MARINA IN A PACIFIC NORTHWEST ESTUARY: WHAT FACTORS CONTROL INTERTIDAL DISTRIBUTION?

    EPA Science Inventory

    The impact of four factors (desiccation, macroalgae, erosion, light) on the distribution of Zostera marina was examined across tidal and bathymetric slope gradients. Data detailing seagrass characteristics, including 1 production, macroalgae biomass and sediment characteristics ...

  19. LMI Based Robust Blood Glucose Regulation in Type-1 Diabetes Patient with Daily Multi-meal Ingestion

    NASA Astrophysics Data System (ADS)

    Mandal, S.; Bhattacharjee, A.; Sutradhar, A.

    2014-04-01

    This paper illustrates the design of a robust output feedback H ∞ controller for the nonlinear glucose-insulin (GI) process in a type-1 diabetes patient to deliver insulin through intravenous infusion device. The H ∞ design specification have been realized using the concept of linear matrix inequality (LMI) and the LMI approach has been used to quadratically stabilize the GI process via output feedback H ∞ controller. The controller has been designed on the basis of full 19th order linearized state-space model generated from the modified Sorensen's nonlinear model of GI process. The resulting controller has been tested with the nonlinear patient model (the modified Sorensen's model) in presence of patient parameter variations and other uncertainty conditions. The performance of the controller was assessed in terms of its ability to track the normoglycemic set point of 81 mg/dl with a typical multi-meal disturbance throughout a day that yields robust performance and noise rejection.

  20. Disulfide Bond Reduction of Von Willebrand Factor by ADAMTS-13†

    PubMed Central

    Yeh, Hui-Chun; Zhou, Zhou; Choi, Hiuwan; Tekeoglu, Senem; May, William; Wang, Christina; Turner, Nancy; Scheiflinger, Friedrich; Moake, Joel L.; Dong, Jing-fei

    2010-01-01

    Summary Background von Willebrand factor (VWF) released from endothelial cells is rich in ultra-large (UL) multimers that are intrinsically active in binding platelets, whereas plasma-type VWF multimers require shear stress to be activated. This functional difference may be attributed to thiols exposed on the surface of plasma-type VWF multimers, but not on ULVWF multimers. Shear stress induces the exposed thiols to form disulfide bonds between laterally apposed plasma-type VWF multimers, leading to enhanced VWF binding to platelets. Objectives We tested a hypothesis that ADAMTS-13 has a disulfide bond-reducing activity that regulates shear-induced thiol-disulfide exchange of VWF. Methods Thiol blocking agents and active thiol bead capturing were used to identify and locate this activity; along with truncated ADAMTS-13 mutants. Results ADAMTS-13 contains a disulfide-bond–reducing activity that primarily targets disulfide bonds in plasma-type VWF multimers induced by high shear stress or formed with thiol beads, but not on disulfide bonds in native multimeric structures. Cysteine thiols targeted by this activity are in the VWF C-domain and are known to participate in shear-induced thiol-disulfide exchange. ADAMTS-13 contains cysteine thiols that remain exposed after being subjected to hydrodynamic forces. Blocking these active thiols eliminates this reducing activity and moderately decreases ADAMTS-13 activity in cleaving ULVWF strings anchored to endothelial cells under flow conditions, but not under static conditions. The activity is located in the C-terminal region of ADAMTS-13. Conclusions This novel disulfide-bond-reducing activity of ADAMTS-13 may prevent covalent lateral association and increased platelet adherence of plasma-type VWF multimers induced by high fluid shear stress. PMID:20946172

  1. Bacterial Sigma Factors and Anti-Sigma Factors: Structure, Function and Distribution

    PubMed Central

    Paget, Mark S.

    2015-01-01

    Sigma factors are multi-domain subunits of bacterial RNA polymerase (RNAP) that play critical roles in transcription initiation, including the recognition and opening of promoters as well as the initial steps in RNA synthesis. This review focuses on the structure and function of the major sigma-70 class that includes the housekeeping sigma factor (Group 1) that directs the bulk of transcription during active growth, and structurally-related alternative sigma factors (Groups 2–4) that control a wide variety of adaptive responses such as morphological development and the management of stress. A recurring theme in sigma factor control is their sequestration by anti-sigma factors that occlude their RNAP-binding determinants. Sigma factors are then released through a wide variety of mechanisms, often involving branched signal transduction pathways that allow the integration of distinct signals. Three major strategies for sigma release are discussed: regulated proteolysis, partner-switching, and direct sensing by the anti-sigma factor. PMID:26131973

  2. Interactions of von Willebrand factor and ADAMTS13 in von Willebrand disease and thrombotic thrombocytopenic purpura.

    PubMed

    Budde, U; Schneppenheim, R

    2014-01-01

    The function of von Willebrand factor (VWF), a huge multimeric protein and a key factor in platelet dependent primary haemostasis, is regulated by its specific protease ADAMTS13. The ADAMTS13 dependent degradation of VWF to its proteolytic fragments can be visualized as a characteristic so-called triplet structure of individual VWF oligomers by multimer analysis. Lack of VWF high molecular weight multimers (VWF-HMWM) or their pathologically enhanced degradation underlies a particular type of von Willebrand disease, VWD type 2A with a significant bleeding tendency, and may also be observed in acquired von Willebrand syndrome due to cardiovascular disease. In these conditions multimer analysis is an obligatory and powerful tool for diagnosis of VWD. The opposite condition, the persistence of ultralarge VWF (UL-VWF) multimers may cause the microangiopathic life-threatening disorder thrombotic thrombocytopenic purpura (TTP). During the course of active TTP, UL-VWF is consumed in the hyaline thrombi formed in the microvasculature which will ultimately result in the loss of UL-VWF and VWF-HMWM. Therefore, VWF multimer analysis is not a valid tool to diagnose TTP in the active phase of disease but may be helpful for the diagnosis of TTP patients in remission. PMID:25010251

  3. Factors determining the distribution and abundance of Dreissena polymorpha in lakes, dam reserviors and channels

    SciTech Connect

    Karatayev, A.

    1995-06-01

    This article addresses the several factors affecting the distribution and abundance of Dreissena polymorphia in bodies of water. Factors covered include: (1) salinity, (2) oxygen level, (3) temperature, (4) substrate, (5) depth, and (6) water chemistry. The analysis of the data allowed the specification of limiting or optimal concentrations of the principle abiotic parameters.

  4. Skyrme model πNN form factor and the sea quark distribution of the nucleon

    NASA Astrophysics Data System (ADS)

    Fries, R. J.; Schäfer, A.

    1998-06-01

    We calculate the sea quark distribution of the nucleon in a meson cloud model. The novel feature of our calculation is the implementation of a special πNN form factor recently obtained by Holzwarth and Machleidt. This form factor is hard for small and soft for large momentum transfers. We show that this feature leads to a substantial improvement.

  5. Life on the boundary: Environmental factors as drivers of habitat distribution in the littoral zone

    NASA Astrophysics Data System (ADS)

    Cefalì, Maria Elena; Cebrian, Emma; Chappuis, Eglantine; Pinedo, Susana; Terradas, Marc; Mariani, Simone; Ballesteros, Enric

    2016-04-01

    The boundary between land and sea, i.e. the littoral zone, is home to a large number of habitats whose distribution is primarily driven by the distance to the sea level but also by other environmental factors such as littoral's geomorphological features, wave exposure, water temperature or orientation. Here we explore the relative importance of those major environmental factors that drive the presence of littoral rocky habitats along 1100 Km of Catalonia's shoreline (Spain, NW Mediterranean) by using Geographic Information Systems and Generalized Linear Models. The distribution of mediolittoral and upper infralittoral habitats responded to different environmental factors. Mediolittoral habitats showed regional differences drawn by sea-water temperature and substrate type. Wave exposure (hydrodynamism), slope and geological features were only relevant to those mediolittoral habitats with specific environmental needs. We did not find any regional pattern of distribution in upper infralittoral habitats, and selected factors only played a moderate role in habitat distribution at the local scale. This study shows for the first time that environmental factors determining habitat distribution differ within the mediolittoral and the upper infralittoral zones and provides the basis for further development of models oriented at predicting the distribution of littoral marine habitats.

  6. Distribution of Balsamorhiza rosea in Rattlesnake Hills with respect to various environmental factors

    SciTech Connect

    Parkhurst, M.A.

    1980-01-01

    Balsamorhiza rosea (Compositae), a suffrutescent perennial, is found on several rocky hilltops with sparse canopy cover in Eastern Washington. This study investigated B. rosea's abundance and its associated species along several physical gradients. Important elements of microclimate selected for this analysis were elevation, slope aspect, slope angle, and soil depth. Results show that the occurrence of B. rosea is associated more strongly with soil depth than with other factors examined. The distribution of B. rosea was not fully explained by the factors in this study. Other potential factors determining its distribution are discussed.

  7. Riverscape factors for controlling fish distribution in a watershed with forest-urban transits

    NASA Astrophysics Data System (ADS)

    Okada, K.

    2012-12-01

    We examined riverscape factors with reach and watershed scales for controlling the presence and abundance of five fish species in 156.1 km2 Asakawa river of Tama-gawa watershed systems in Tokyo Metropolitan. Landuse of the watershed transits from forest to urban development. Based on the preferences of habitat, fish survey was conducted at 39 locations of 50m channel reaches from April and June, 2012 using an electrofisher (Smith-Root. Inc). At reach scale factors, we measured water temperature, dissolved oxygen, stream depth and width, flow velocity, substrate composition (sand, gravel and rock). For watershed scale factors, we evaluated drainage area, relief height, channel gradient and watershed forest area percentages. Masu salmon (Oncorhynchus masou masou) distributed in stream channels within 25km2 watershed area and 90% forested areas. Sculpin (Cottus pollux) tended to be distributed similar ranged of masu salmon. In contrast, Japanese dace (Tribolodon hakonensis) and sand loach (Cobitis biwae) tended to distributed to over 5km2 watershed area and 16% forested area. Because masu salmon and sculpin depended on macroinvertebrates and input terrestrial invertebrates food sources, limited habitat only occurred in the upstream areas. Distribution of these fish and their control factors marginally agreed to the database of fish distribution sampled in 1993 and 1997. Our finding suggested that watershed scale factors tended to affect the presence and absence of fish species in channel network, while reach scale factors such as forest ratio and substrate composition affect the abundance of fishes. However, further hydrological processes such as ephemeral and perennial nature of flow and locations of groundwater springs should also be considered as factors for affecting fish distribution in the channel network.

  8. Single-molecule force measurements of the polymerizing dimeric subunit of von Willebrand factor

    NASA Astrophysics Data System (ADS)

    Wijeratne, Sithara S.; Li, Jingqiang; Yeh, Hui-Chun; Nolasco, Leticia; Zhou, Zhou; Bergeron, Angela; Frey, Eric W.; Moake, Joel L.; Dong, Jing-fei; Kiang, Ching-Hwa

    2016-01-01

    Von Willebrand factor (VWF) multimers are large adhesive proteins that are essential to the initiation of hemostatic plugs at sites of vascular injury. The binding of VWF multimers to platelets, as well as VWF proteolysis, is regulated by shear stresses that alter VWF multimeric conformation. We used single molecule manipulation with atomic force microscopy (AFM) to investigate the effect of high fluid shear stress on soluble dimeric and multimeric forms of VWF. VWF dimers are the smallest unit that polymerizes to construct large VWF multimers. The resistance to mechanical unfolding with or without exposure to shear stress was used to evaluate VWF conformational forms. Our data indicate that, unlike recombinant VWF multimers (RVWF), recombinant dimeric VWF (RDVWF) unfolding force is not altered by high shear stress (100 dynes/cm2 for 3 min at 37°C ). We conclude that under the shear conditions used (100 dynes/cm2 for 3 min at 37°C ) , VWF dimers do not self-associate into a conformation analogous to that attained by sheared large VWF multimers.

  9. Health care expenditure disparities in the European Union and underlying factors: a distribution dynamics approach.

    PubMed

    Villaverde, José; Maza, Adolfo; Hierro, María

    2014-09-01

    This paper examines health care expenditure (HCE) disparities between the European Union countries over the period 1995-2010. By means of using a continuous version of the distribution dynamics approach, the key conclusions are that the reduction in disparities is very weak and, therefore, persistence is the main characteristic of the HCE distribution. In view of these findings, a preliminary attempt is made to add some insights into potentially main factors behind the HCE distribution. The results indicate that whereas per capita income is by far the main determinant, the dependency ratio and female labour participation do not play any role in explaining the HCE distribution; as for the rest of the factors studied (life expectancy, infant mortality, R&D expenditure and public HCE expenditure share), we find that their role falls somewhat in between. PMID:24823964

  10. A Distributed Simulation Facility to Support Human Factors Research in Advanced Air Transportation Technology

    NASA Technical Reports Server (NTRS)

    Amonlirdviman, Keith; Farley, Todd C.; Hansman, R. John, Jr.; Ladik, John F.; Sherer, Dana Z.

    1998-01-01

    A distributed real-time simulation of the civil air traffic environment developed to support human factors research in advanced air transportation technology is presented. The distributed environment is based on a custom simulation architecture designed for simplicity and flexibility in human experiments. Standard Internet protocols are used to create the distributed environment, linking all advanced cockpit simulator, all Air Traffic Control simulator, and a pseudo-aircraft control and simulation management station. The pseudo-aircraft control station also functions as a scenario design tool for coordinating human factors experiments. This station incorporates a pseudo-pilot interface designed to reduce workload for human operators piloting multiple aircraft simultaneously in real time. The application of this distributed simulation facility to support a study of the effect of shared information (via air-ground datalink) on pilot/controller shared situation awareness and re-route negotiation is also presented.

  11. Relationship between Specific Distributions of Isolated Soleal Vein Thrombosis and Risk Factors

    PubMed Central

    Ohgi, Nagako

    2014-01-01

    Objective: The relationship between specific distributions of isolated soleal vein thrombosis (SVT) and risk factors was investigated. Subjects and Methods: The subjects included 93 patients with SVT diagnosed with ultrasonography. Results: In the acute thrombus distribution, the thrombi of central veins were significantly more frequent than the thrombi of medial veins in the unilateral SVT. The thrombi of central veins were not more significantly frequent than the thrombi of medial veins in the bilateral SVT. Conclusion: The risk factors of bilateral SVT are considered to be different from that of the unilateral SVT. (*English translation of J Jpn Coll Angiol 2013; 53: 159-166) PMID:25298825

  12. [CCA of water beetles' distribution and environmental factors in lentic samples of north Changbai Mountain].

    PubMed

    We, Yulian; Ji, Lanzhu; Wang, Miao; Zhao, Min

    2002-01-01

    The relationship between 28 species water beetles in 12 lentic samples and environmental factors of North Chang-bai Mountain was studied by Cononical Correspondence Analysis (CCA). The results showed that degree of underwater humus and altitude are the major factors correlated with beetles distribution, and the correlation coefficients of environmental factors and axes of CCA were 0.8371 and 0.7206 respectively, while water temperature and plant density also had certain effects. Under the influence of environmental factors, the water beetles' populations were different in different habitat. Coelambus impressopunctatus, Colymbetes magnus, Helophorus browni, Haliplus spp. distributed in deep water pool. Water temperature was not important for those beetles. Ilybius sp. and Limnebius glabriventris correlated with altitude and humus. PMID:11962329

  13. Interpreting the neutron's electric form factor: Rest frame charge distribution or foldy term?

    SciTech Connect

    Nathan Isgur

    1998-12-01

    The neutron's electric form factor contains vital information on nucleon structure, but its interpretation within many models has been obscured by relativistic effects. The author demonstrates that, to leading order in the relativistic expansion of a constituent quark model, the Foldy term cancels exactly against a contribution to the Dirac form factor F{sub 1} to leave intact the naive interpretation of G{sup n}{sub E} as arising from the neutron's rest frame charge distribution.

  14. Biomechanical, psychosocial and individual risk factors predicting low back functional impairment among furniture distribution employees

    PubMed Central

    Ferguson, Sue A.; Allread, W. Gary; Burr, Deborah L.; Heaney, Catherine; Marras, William S.

    2013-01-01

    Background Biomechanical, psychosocial and individual risk factors for low back disorder have been studied extensively however few researchers have examined all three risk factors. The objective of this was to develop a low back disorder risk model in furniture distribution workers using biomechanical, psychosocial and individual risk factors. Methods This was a prospective study with a six month follow-up time. There were 454 subjects at 9 furniture distribution facilities enrolled in the study. Biomechanical exposure was evaluated using the American Conference of Governmental Industrial Hygienists (2001) lifting threshold limit values for low back injury risk. Psychosocial and individual risk factors were evaluated via questionnaires. Low back health functional status was measured using the lumbar motion monitor. Low back disorder cases were defined as a loss of low back functional performance of −0.14 or more. Findings There were 92 cases of meaningful loss in low back functional performance and 185 non cases. A multivariate logistic regression model included baseline functional performance probability, facility, perceived workload, intermediated reach distance number of exertions above threshold limit values, job tenure manual material handling, and age combined to provide a model sensitivity of 68.5% and specificity of 71.9%. Interpretation: The results of this study indicate which biomechanical, individual and psychosocial risk factors are important as well as how much of each risk factor is too much resulting in increased risk of low back disorder among furniture distribution workers. PMID:21955915

  15. Influence of weather and animal related factors on grazing distribution of livestock

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Automated monitoring of animal locations at relatively short time intervals has allowed new insights into how biotic and abiotic factors influence spatial distribution patterns of livestock. We will discuss recently completed and on-going grazing behavior studies using GPS/GIS approaches at sites in...

  16. Exploratory Data Analysis to Identify Factors Influencing Spatial Distributions of Weed Seed Banks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Comparing distributions of different species in multiple fields will help us understand the spatial dynamics of weed seed banks, but analyzing observational data requires non-traditional statistical methods. We used classification and regression tree analysis (CART) to investigate factors that influ...

  17. 25 CFR Appendix C to Subpart C - Relative Need Distribution Factor

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Relative Need Distribution Factor C Appendix C to Subpart C Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Indian Reservation Roads Program Funding Pt. 170, Subpt. C, App. C Appendix C to Subpart...

  18. 25 CFR Appendix C to Subpart C - Relative Need Distribution Factor

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Relative Need Distribution Factor C Appendix C to Subpart C Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Indian Reservation Roads Program Funding Pt. 170, Subpt. C, App. C Appendix C to Subpart...

  19. DEVELOPMENT OF STATISTICAL DISTRIBUTIONS OR RANGES OF STANDARD FACTORS USED IN EXPOSURE ASSESSMENTS

    EPA Science Inventory

    This document is intended to support EPA's Exposure Assessment Guidelines by providing data and information on standard factors that are used to calculate human exposure to toxic substances. tatistical distributions or ranges of values were developed for body weight, skin surface...

  20. Lorentz factor distribution of blazars from the optical Fundamental Plane of black hole activity

    NASA Astrophysics Data System (ADS)

    Saikia, Payaswini; Körding, Elmar; Falcke, Heino

    2016-09-01

    Blazar radiation is dominated by a relativistic jet which can be modelled at first approximation using just two intrinsic parameters - the Lorentz factor Γ and the viewing angle θ. Blazar jet observations are often beamed due to relativistic effects, complicating the understanding of these intrinsic properties. The most common way to estimate blazar Lorentz factors needs the estimation of apparent jet speeds and Doppler beaming factors. We present a new and independent method of constructing the blazar Lorentz factor distribution, using the optical Fundamental Plane of black hole activity. The optical Fundamental Plane is a plane stretched out by both the supermassive black holes and the X-ray binaries, in the 3D space provided by their [O III] line luminosity, radio luminosity and black hole mass. We use the intrinsic radio luminosity obtained from the optical Fundamental Plane to constrain the boosting parameters of the VLBA Imaging and Polarimetry Survey blazar sample. We find a blazar bulk Lorentz factor distribution in the form of a power law as N(Γ) ∝ Γ-2.1 ± 0.4 for the Γ range of 1-40. We also discuss the viewing angle distribution of the blazars and the dependence of our results on the input parameters.

  1. Lorentz factor distribution of blazars from the optical Fundamental plane of black hole activity

    NASA Astrophysics Data System (ADS)

    Saikia, Payaswini; Körding, Elmar; Falcke, Heino

    2016-06-01

    Blazar radiation is dominated by a relativistic jet which can be modeled at first approximation using just two intrinsic parameters - the Lorentz factor Γ and the viewing angle θ. Blazar jet observations are often beamed due to relativistic effects, complicating the understanding of these intrinsic properties. The most common way to estimate blazar Lorentz factors needs the estimation of apparent jet speeds and Doppler beaming factors. We present a new and independent method of constructing the blazar Lorentz factor distribution, using the optical fundamental plane of black hole activity. The optical fundamental plane is a plane stretched out by both the supermassive black holes and the X-ray binaries, in the 3D space provided by their [OIII] line luminosity, radio luminosity and black hole mass. We use the intrinsic radio luminosity obtained from the optical fundamental plane to constrain the boosting parameters of the VLBA Imaging and Polarimetry Survey (VIPS) blazar sample. We find a blazar bulk Lorentz factor distribution in the form of a power law as N(Γ)∝Γ-2.1 ± 0.4 for the Γ range of 1 to 40. We also discuss the viewing angle distribution of the blazars and the dependence of our results on the input parameters.

  2. Distribution of some daily and seasonal events in relation to changes of physical factors

    NASA Astrophysics Data System (ADS)

    Dreisig, H.; Nachman, G.

    1983-03-01

    A special case of the Weibull distribution model is used in describing the course of behavioural transformation processes in relation to some cyclic physical factor. The model assumes that the rate of the process increases, the less inhibiting the physical factor, and the faster the factor changes. However, due to some resistance or a depletion, the rate slows down, the further the process progresses. The model was tested on the daily onset of activity in nocturnal insects, daily roosting flight of blackbirds, dark and light adaptation by pigment migration in insect eyes, photoperiodic response of an insect, and daily emergence of tiger beetles. The assumptions of the model are tested and discussed. One of these is violated in unnaturally fast changes of the physical factor because the process reaches some constant minimum duration, and proportionality between rate of process and rate of factor can no longer be maintained.

  3. Risk factor distribution for cardiovascular diseases among high school boys and girls of urban Dibrugarh, Assam

    PubMed Central

    Ekta, Gupta; Tulika, Mahanta Goswami

    2016-01-01

    Introduction: Chronic noncommunicable diseases (NCDs) including cardiovascular diseases (CVDs) are the leading cause of death in the world, and their incidence is rising rapidly due to increasing rates of risk factors such as hypertension, dyslipidemia, diabetes, obesity, physical inactivity, and tobacco use. These risk factors track from childhood to adulthood, and their distribution varies among males and females; hence, there is a need to determine risk factor prevalence among adolescent age group so as to plan preventive strategies. Objective: To determine the distribution of risk factors of CVDs amongst high school boys and girls of urban Dibrugarh, Assam. Subjects and Methods: A cross-sectional study was conducted from October 2012 to June 2013 in the schools of urban Dibrugarh, Assam wherein data was collected from 1000 students of Class 8–10 using multistage random sampling and risk factors were assessed using WHO steps methodology. Statistical Analysis: Statistical analysis was done using SPSS 16 software and test of differences used were Chi-square test and t-test. Results: The prevalence of ever tobacco use was 32.3% among boys and 6.6% among girls (P < 0.001) while ever alcohol use was reported by 11.9% boys and 1% girls (P < 0.001). Prevalence of overweight and hypertension was found to be higher among girls (11.7% and 24.1%) as compared to boys (6.8% and 18.1%). Prevalence of hypercholesterolemia was higher among boys while high triglycerides levels were more prevalent among girls. Conclusion: The study revealed a high prevalence of various risk factors among boys and girls. There is a need to reduce the risk factor prevalence of CVD among this group of the population to address the future epidemic of NCD. Different health promotional activities need to be implemented to target boys and girls as the risk factor distribution among these groups is different. PMID:27453853

  4. Using Comparison Data to Differentiate Categorical and Dimensional Data by Examining Factor Score Distributions: Resolving the Mode Problem

    ERIC Educational Resources Information Center

    Ruscio, John; Walters, Glenn D.

    2009-01-01

    Factor-analytic research is common in the study of constructs and measures in psychological assessment. Latent factors can represent traits as continuous underlying dimensions or as discrete categories. When examining the distributions of estimated scores on latent factors, one would expect unimodal distributions for dimensional data and bimodal…

  5. Source apportionment of ambient fine particle size distribution using positive matrix factorization in Erfurt, Germany

    PubMed Central

    Yue, Wei; Stölzel, Matthias; Cyrys, Josef; Pitz, Mike; Heinrich, Joachim; Kreyling, Wolfgang G.; Wichmann, H.-Erich; Peters, Annette; Wang, Sheng; Hopke, Philip K.

    2008-01-01

    Particle size distribution data collected between September 1997 and August 2001 in Erfurt, Germany were used to investigate the sources of ambient particulate matter by positive matrix factorization (PMF). A total of 29,313 hourly averaged particle size distribution measurements covering the size range of 0.01 to 3.0 μm were included in the analysis. The particle number concentrations (cm−3) for the 9 channels in the ultrafine range, and mass concentrations (ng m−3) for the 41 size bins in the accumulation mode and particle up to 3 μm in aerodynamic diameter were used in the PMF. The analysis was performed separately for each season. Additional analyses were performed including calculations of the correlations of factor contributions with gaseous pollutants (O3, NO, NO2, CO and SO2) and particle composition data (sulfate, organic carbon and elemental carbon), estimating the contributions of each factor to the total number and mass concentration, identifying the directional locations of the sources using the conditional probability function, and examining the diurnal patterns of factor scores. These results were used to assist in the interpretation of the factors. Five factors representing particles from airborne soil, ultrafine particles from local traffic, secondary aerosols from local fuel combustion, particles from remote traffic sources, and secondary aerosols from multiple sources were identified in all seasons. PMID:18433834

  6. Spatiotemporal dataset on Chinese population distribution and its driving factors from 1949 to 2013

    PubMed Central

    Wang, Lizhe; Chen, Lajiao

    2016-01-01

    Spatio-temporal data on human population and its driving factors is critical to understanding and responding to population problems. Unfortunately, such spatio-temporal data on a large scale and over the long term are often difficult to obtain. Here, we present a dataset on Chinese population distribution and its driving factors over a remarkably long period, from 1949 to 2013. Driving factors of population distribution were selected according to the push-pull migration laws, which were summarized into four categories: natural environment, natural resources, economic factors and social factors. Natural environment and natural resources indicators were calculated using Geographic Information System (GIS) and Remote Sensing (RS) techniques, whereas economic and social factors from 1949 to 2013 were collected from the China Statistical Yearbook and China Compendium of Statistics from 1949 to 2008. All of the data were quality controlled and unified into an identical dataset with the same spatial scope and time period. The dataset is expected to be useful for understanding how population responds to and impacts environmental change. PMID:27377410

  7. Spatiotemporal dataset on Chinese population distribution and its driving factors from 1949 to 2013.

    PubMed

    Wang, Lizhe; Chen, Lajiao

    2016-01-01

    Spatio-temporal data on human population and its driving factors is critical to understanding and responding to population problems. Unfortunately, such spatio-temporal data on a large scale and over the long term are often difficult to obtain. Here, we present a dataset on Chinese population distribution and its driving factors over a remarkably long period, from 1949 to 2013. Driving factors of population distribution were selected according to the push-pull migration laws, which were summarized into four categories: natural environment, natural resources, economic factors and social factors. Natural environment and natural resources indicators were calculated using Geographic Information System (GIS) and Remote Sensing (RS) techniques, whereas economic and social factors from 1949 to 2013 were collected from the China Statistical Yearbook and China Compendium of Statistics from 1949 to 2008. All of the data were quality controlled and unified into an identical dataset with the same spatial scope and time period. The dataset is expected to be useful for understanding how population responds to and impacts environmental change. PMID:27377410

  8. [Spatiotemporal distribution of negative air ion concentration in urban area and related affecting factors: a review].

    PubMed

    Huang, Xiang-Hua; Wang, Jian; Zeng, Hong-Da; Chen, Guang-Shui; Zhong, Xian-Fang

    2013-06-01

    Negative air ion (NAI) concentration is an important indicator comprehensively reflecting air quality, and has significance to human beings living environment. This paper summarized the spatiotemporal distribution features of urban NAI concentration, and discussed the causes of these features based on the characteristics of the environmental factors in urban area and their effects on the physical and chemical processes of NAI. The temporal distribution of NAI concentration is mainly controlled by the periodic variation of solar radiation, while the spatial distribution of NAI concentration along the urban-rural gradient is mainly affected by the urban aerosol distribution, underlying surface characters, and urban heat island effect. The high NAI concentration in urban green area is related to the vegetation life activities and soil radiation, while the higher NAI concentration near the water environment is attributed to the water molecules that participate in the generation of NAI through a variety of ways. The other environmental factors can also affect the generation, life span, component, translocation, and distribution of NAI to some extent. To increase the urban green space and atmospheric humidity and to maintain the soil natural attributes of underlying surface could be the effective ways to increase the urban NAI concentration and improve the urban air quality. PMID:24066568

  9. Analysis of synoptic scale controlling factors in the distribution of gravity wave potential energy

    NASA Astrophysics Data System (ADS)

    Yang, Shih-Sian; Pan, C. J.; Das, Uma; Lai, H. C.

    2015-12-01

    In the past years, global morphology and climatology of gravity waves have been widely studied and the effects of topography and convection systems have been evaluated, but the complete gravity wave distribution could not be explained by these effects. To find the missing controlling factors, a series of synoptic scale analyses is performed in the present study to investigate relationships between synoptic scale factors and potential energy (Ep) associated with gravity waves. Global distribution of Ep during a 12-year period from 2002 to 2013 is derived using temperature profiles retrieved from observations of Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite. Synoptic scale factors obtained from ECMWF Interim reanalysis data are employed to investigate the correlation between synoptic systems and Ep. It is found that Ep values are high around extratropical cyclones over mid-latitudes (30-60°) and around the Intertropical Convergence Zone (ITCZ) over low-latitudes (10-30°). Ep values are low around subtropical highs over both mid- and low-latitudes. This is the first time that a synoptic scale analysis of Ep distribution is performed, and the influence of synoptic scale factors on Ep confirmed.

  10. Factors Affecting the Distribution Pattern of Wild Plants with Extremely Small Populations in Hainan Island, China

    PubMed Central

    Chen, Yukai; Yang, Xiaobo; Yang, Qi; Li, Donghai; Long, Wenxing; Luo, Wenqi

    2014-01-01

    Understanding which factors affect the distribution pattern of extremely small populations is essential to the protection and propagation of rare and endangered plant species. In this study, we established 108 plots covering the entire Hainan Island, and measured the appearance frequency and species richness of plant species with extremely small populations, as well as the ecological environments and human disturbances during 2012–2013. We explored how the ecological environments and human activities affected the distribution pattern of these extremely small populations. Results showed that the extremely small populations underwent human disturbances and threats, and they were often found in fragmental habitats. The leading factors changing the appearance frequency of extremely small populations differed among plant species, and the direct factors making them susceptible to extinction were human disturbances. The peak richness of extremely small populations always occurred at the medium level across environmental gradients, and their species richness always decreased with increasing human disturbances. However, the appearance frequencies of three orchid species increased with the increasing human disturbances. Our study thus indicate that knowledge on how the external factors, such as the ecological environment, land use type, roads, human activity, etc., affect the distribution of the extremely small populations should be taken for the better protecting them in the future. PMID:24830683

  11. Factors affecting the distribution pattern of wild plants with extremely small populations in Hainan Island, China.

    PubMed

    Chen, Yukai; Yang, Xiaobo; Yang, Qi; Li, Donghai; Long, Wenxing; Luo, Wenqi

    2014-01-01

    Understanding which factors affect the distribution pattern of extremely small populations is essential to the protection and propagation of rare and endangered plant species. In this study, we established 108 plots covering the entire Hainan Island, and measured the appearance frequency and species richness of plant species with extremely small populations, as well as the ecological environments and human disturbances during 2012-2013. We explored how the ecological environments and human activities affected the distribution pattern of these extremely small populations. Results showed that the extremely small populations underwent human disturbances and threats, and they were often found in fragmental habitats. The leading factors changing the appearance frequency of extremely small populations differed among plant species, and the direct factors making them susceptible to extinction were human disturbances. The peak richness of extremely small populations always occurred at the medium level across environmental gradients, and their species richness always decreased with increasing human disturbances. However, the appearance frequencies of three orchid species increased with the increasing human disturbances. Our study thus indicate that knowledge on how the external factors, such as the ecological environment, land use type, roads, human activity, etc., affect the distribution of the extremely small populations should be taken for the better protecting them in the future. PMID:24830683

  12. Correlation energy, structure factor, radial distribution function, and momentum distribution of the spin-polarized uniform electron gas

    NASA Astrophysics Data System (ADS)

    Ortiz, G.; Ballone, P.

    1994-07-01

    The properties of the three-dimensional uniform electron gas in the Fermi liquid regime are analyzed using variational Monte Carlo (VMC) and fixed-node diffusion Monte Carlo methods. Our study extends those of Ceperley [Phys. Rev. B 18, 3126 (1978)] and Ceperley and Alder [Phys. Rev. Lett. 45, 566 (1980)] to larger system sizes with improved statistics and, more importantly, to partial spin polarization. The density range 0.8<=rs<=10, which is the most relevant for density functional computations, is studied in detail. We analyze the size dependence of the simulation results and present an extended set of correlation energies extrapolated to the thermodynamic limit. Using the VMC method we analyze the spin dependence of the correlation energy, and we compare our results to several interpolation formulas used in density functional calculations. We summarize our results by a simple interpolation formula. In addition, we present results for the radial distribution function, the structure factor, the momentum distribution, and triplet correlation functions, and we discuss the comparison with many-body semianalytic theories.

  13. Factorization and reduction methods for optimal control of distributed parameter systems

    NASA Technical Reports Server (NTRS)

    Burns, J. A.; Powers, R. K.

    1985-01-01

    A Chandrasekhar-type factorization method is applied to the linear-quadratic optimal control problem for distributed parameter systems. An aeroelastic control problem is used as a model example to demonstrate that if computationally efficient algorithms, such as those of Chandrasekhar-type, are combined with the special structure often available to a particular problem, then an abstract approximation theory developed for distributed parameter control theory becomes a viable method of solution. A numerical scheme based on averaging approximations is applied to hereditary control problems. Numerical examples are given.

  14. Soft and collinear factorization and transverse momentum dependent parton distribution functions

    NASA Astrophysics Data System (ADS)

    Echevarría, Miguel G.; Idilbi, Ahmad; Scimemi, Ignazio

    2013-11-01

    In this work we consider how a parton distribution function, with an explicit transverse momentum dependence can be properly defined in a regularization-scheme independent manner. We argue that by considering a factorized form of the transverse momentum dependent spectrum for the production of a heavy lepton pair in Drell-Yan reaction, one should first split the relevant soft function into two boost invariant contributions. When those soft contributions are added to the pure collinear contributions, well-defined hadronic matrix elements emerge, i.e., the transverse momentum dependent distributions. We also perform a comparison with Collins' definition.

  15. Altered interaction and distribution of glycosaminoglycans and growth factors in mucopolysaccharidosis type I bone disease.

    PubMed

    Kingma, Sandra D K; Wagemans, Tom; IJlst, Lodewijk; Bronckers, Antonius L J J; van Kuppevelt, Toin H; Everts, Vincent; Wijburg, Frits A; van Vlies, Naomi

    2016-07-01

    The mucopolysaccharidoses (MPSs) comprise a group of lysosomal storage disorders characterized by deficient degradation and subsequent accumulation of glycosaminoglycans (GAGs). Progressive bone and joint disease are a major cause of morbidity, and current therapeutic strategies have limited effect on these symptoms. By elucidating pathophysiological mechanisms underlying bone disease, new therapeutic targets may be identified. Longitudinal growth is regulated by interaction between GAGs and growth factors. Because GAGs accumulate in the MPSs, we hypothesized that altered interaction between growth factors and GAGs contribute to the pathogenesis of MPS bone disease. In this study, binding between GAGs from MPS I chondrocytes and fibroblast growth factor 2 (FGF2) was not significantly different from binding of FGF2 to GAGs from control chondrocytes. FGF2 signaling, however, was increased in MPS I chondrocytes after incubation with FGF2, as compared to control chondrocytes. Using bone cultures, we demonstrated decreased growth of WT mouse bones after incubation with FGF2, but no effect on MPS I bone growth. However, MPS I bones showed decreased growth in the presence of GAGs from MPS I chondrocytes. Finally, we demonstrate altered GAG distribution in MPS I chondrocytes, and altered GAG, FGF2 and Indian hedgehog distribution in growth plates from MPS I mice. In summary, our results suggest that altered interaction and distribution of growth factors and accumulated GAGs may contribute to the pathogenesis of MPS bone disease. In the future, targeting growth factor regulation or the interaction between in growth factors and GAGs might be a promising therapeutic strategy for MPS bone disease. PMID:27105565

  16. Form factors and generalized parton distributions in basis light-front quantization

    NASA Astrophysics Data System (ADS)

    Adhikari, Lekha; Li, Yang; Zhao, Xingbo; Maris, Pieter; Vary, James P.; El-Hady, Alaa Abd

    2016-05-01

    We calculate the elastic form factors and the generalized parton distributions (GPDs) for four low-lying bound states of a demonstration fermion-antifermion system, strong-coupling positronium (e e ¯ ), using basis light-front quantization (BLFQ). By using this approach, we also calculate the impact-parameter-dependent GPDs q (x ,b⃗⊥) to visualize the fermion density in the transverse plane (b⃗⊥). We compare selected results with corresponding quantities in the nonrelativistic limit to reveal relativistic effects. Our results establish the foundation within BLFQ for investigating the form factors and the GPDs for hadronic systems.

  17. Distribution of deep-water corals along the North American continental margins: Relationships with environmental factors

    NASA Astrophysics Data System (ADS)

    Bryan, Tanya L.; Metaxas, Anna

    2006-12-01

    Despite the increasing attention to assemblages of deep-water corals in the past decade, much of this research has been focused on documenting and enumerating associated fauna. However, an understanding of the distribution of most species of coral and the ecological processes associated with these assemblages is still lacking. In this study, we qualitatively and quantitatively described the habitats of two families of deep-water corals in relation to six oceanographic factors (depth, slope, temperature, current, chlorophyll a concentration and substrate) on the Pacific and Atlantic Continental Margins of North America (PCM and ACM study areas, respectively). This study focused primarily on the distributions of Primnoidae and Paragorgiidae because of the large number of documented occurrences. For each environmental factor, deep-water coral locations were compared to the surrounding environment using χ2 tests. On both continental margins, coral locations were found to be not randomly distributed within the study areas, but were within specific ranges for most environmental factors. In the PCM study area, Paragorgiidae and Primnoidae locations were found in areas with slopes ranging from 0° to 10.0°, temperature from -2.0 to 11.0 °C and currents from 0 to 143 cm s -1. In the ACM study area, Paragorgiidae and Primnoidae locations were found in areas with slopes ranging from 0° to 1.4°, temperature ranging from 0 to 11.0 °C and currents ranging from 0 to 207 cm s -1. Although the patterns in habitat characteristics were similar, differences existed between families with respect to particular environmental factors. In both study areas, most environmental parameters in locations where corals occurred were significantly different from the average values of these parameters as determined with χ2 tests ( p<0.05) except for substrate in Paragorgiidae locations and depth in Primnoidae locations on the PCM. This is the first study to show coral distributional patterns

  18. Factors controlling spatial distribution patterns of biocrusts in a heterogeneous and topographically complex semiarid area

    NASA Astrophysics Data System (ADS)

    Chamizo, Sonia; Rodríguez-Caballero, Emilio; Roncero, Beatriz; Raúl Román, José; Cantón, Yolanda

    2016-04-01

    Biocrusts are widespread soil components in drylands all over the world. They are known to play key roles in the functioning of these regions by fixing carbon and nitrogen, regulating hydrological processes, and preventing from water and wind erosion, thus reducing the loss of soil resources and increasing soil fertility. The rate and magnitude of services provided by biocrusts greatly depend on their composition and developmental stage. Late-successional biocrusts such as lichens and mosses have higher carbon and nitrogen fixation rates, and confer greater protection against erosion and the loss of sediments and nutrients than early-successional algae and cyanobacteria biocrusts. Knowledge of spatial distribution patterns of different biocrust types and the factors that control their distribution is important to assess ecosystem services provided by biocrusts at large spatial scales and to improve modelling of biogeochemical processes and water and carbon balance in drylands. Some of the factors that condition biocrust cover and composition are incoming solar radiation, terrain attributes, vegetation distribution patterns, microclimatic variables and soil properties such as soil pH, texture, soil organic matter, soil nutrients and gypsum and CaCO3 content. However, the factors that govern biocrust distribution may vary from one site to another depending on site characteristics. In this study, we examined the influence of abiotic attributes on the spatial distribution of biocrust types in a complex heterogeneous badland system (Tabernas, SE Spain) where biocrust cover up to 50% of the soil surface. From the analysis of relationships between terrain attributes and proportional abundance of biocrust types, it was found that topography exerted a main control on the spatial distribution of biocrust types in this area. SW-facing slopes were dominated by physical soil crusts and were practically devoid of vegetation and biocrusts. Biocrusts mainly occupied the pediments

  19. Discovery of low-affinity preproinsulin epitopes and detection of autoreactive CD8 T-cells using combinatorial MHC multimers.

    PubMed

    Unger, Wendy W; Velthuis, Jurjen; Abreu, Joana R F; Laban, Sandra; Quinten, Edwin; Kester, Michel G D; Reker-Hadrup, Sine; Bakker, Arnold H; Duinkerken, Gaby; Mulder, Arend; Franken, Kees L M C; Hilbrands, Robert; Keymeulen, Bart; Peakman, Mark; Ossendorp, Ferry; Drijfhout, Jan Wouter; Schumacher, Ton N; Roep, Bart O

    2011-11-01

    Autoreactive cytotoxic CD8 T-cells (CTLs) play a key pathogenic role in the destruction of insulin-producing beta-cells resulting in type 1 diabetes. However, knowledge regarding their targets is limited, restricting the ability to monitor the course of the disease and immune interventions. In a multi-step discovery process to identify novel CTL epitopes in human preproinsulin (PPI), PPI was digested with purified human proteasomes, and resulting COOH-fragments aligned with algorithm-predicted HLA-binding peptides to yield nine potential HLA-A1, -A2, -A3 or -B7-restricted candidates. An UV-exchange method allowed the generation of a repertoire of multimers including low-affinity HLA-binding peptides. These were labeled with quantum dot-fluorochromes and encoded in a combinatorial fashion, allowing parallel and sensitive detection of specific, low-avidity T-cells. Significantly increased frequencies of T-cells against four novel PPI epitopes (PPI(4-13)/B7, PPI(29-38)/A2, PPI(76-84)/A3 and PPI(79-88)/A3) were detected in stored blood of patients with recent onset diabetes but not in controls. Changes in frequencies of circulating CD8 T-cells against these novel epitopes were detected in blood of islet graft recipients at different time points after transplantation, which correlated with clinical outcome. In conclusion, our novel strategy involving a sensitive multiplex detection technology and requiring minimal volumes of stored blood represents a major improvement in the direct ex-vivo characterization and enumeration of immune cells in the pathogenesis of type 1 diabetes. PMID:21636247

  20. Physiological and environmental factors associated with central fat distribution in pubertal girls.

    PubMed

    Suder, A; Plonka, M; Jagielski, P; Piorecka, B; Glodzik, J

    2015-06-01

    The aim of the work was to determine a degree of explanation of the variation of central fat distribution described by the waist-to-height ratio (WHtR) and waist circumference (WC) by both environmental and biological factors, including hormonal ones. The authors also intended to define the factors which are connected with a risk of abdominal obesity in girls. The study material includes a cross-sectional sample of 297 girls aged 9–16 years, examined in sport and regular schools in Cracow, Poland. Direct anthropometric measurements were done, breast development was assessed (Tanner stage) and leptin and ghrelin concentration in blood serum was estimated (by RIA method). The girls’ lifestyles and socio-economic status were investigated through survey questionnaires. The stepwise descending regression method was applied to evaluate a degree of WC, WHtR and BMI variation explanation. A logistic regression analysis was conducted to indicate factors connected with a risk of abdominal obesity (WHtR ³ 0.50) by calculating odds ratio (OR) and 95% confidence interval (CI). Variation of WC and WHtR was explained in, respectively, 53% and 44% by biological factors i.e. age, body height, the Tanner stage and blood serum leptin and ghrelin concentration as well as by environmental factors i.e. obesity prevalence in fathers and the girls’ high physical activity. Variation of BMI was explained in 56% by a similar set of variables, excluding the level of physical activity. The biological factors were the highest determinants of an adipose tissue distribution type in the girls. Besides biological factors a significant role was also played by the environmental ones: obesity prevalence in fathers and high level of physical activity. The waist to height ratio seemed to be a more sensitive identifier of environmental behaviours than the general adiposity index. PMID:26084228

  1. [Advance to the research of the climate factor effect on the distribution of plague].

    PubMed

    Zhang, A P; Wei, R J; Xiong, H M; Wang, Z Y

    2016-05-01

    Plague is an anthropozoonotic disease caused by the Yersinia pestis ,which developed by many factors including local climate factors. In recent years, more and more studies on the effects of climate on plague were conducted. According to the researches, climate factors (mainly the rainfall and temperature) affected the development and distribution of plague by influencing the abundance of plague host animals and fleas index. The climate also affected the epidemic dynamics and the scope of plague. There were significant differences existing in the influence of climate on the palgue developed in the north and south China. In the two different plague epidemic systems, the solitary Daurian ground squirrel-flea-plague and the social Mongolian gerbil-flea-plague, the obvious population differences existed among the responses of the host animal to the climate changes. Although the internal relationship between the rainfall, the flea index, the density of rodents and the plague supported the nutritional cascade hypothesis, it can not prove that there is a clear causality between the occurrence of plague and rainfall. So the influence of climate factors on plague distribution can only be used for early forecasting and warning of the plague. PMID:27141906

  2. Type of body fat distribution in postmenopausal women and its related factors

    PubMed Central

    Noroozi, Mahnaz; Rastegari, Zahra; Paknahad, Zamzam

    2010-01-01

    BACKGROUND: The type of body fat distribution has an important role for identifying risk of diseases. One of the simple anthropometric indexes for estimating type of body fat distribution is waist circumference index. This study is aimed to determine the type of body fat distribution in postmenopausal women and its related factors. METHODS: This is a cross sectional descriptive analytical study. Samples were 278 postmenopausal women in Isfahan who were selected by stratified sampling and then were invited to 64 health centers of Isfahan. Data was gathered using a questionnaire and standard meter. Data was analyzed using SPSS software and descriptive and inferential statistics. RESULTS: Results showed that in postmenopausal women the mean of waist circumference index was 93.63 (10.66) and its range was 54 to 119 cm. There was a meaningful relation between job, educational status, total pregnancies, total deliveries, age of first pregnancy, lactation history and menopausal age with waist circumference index. CONCLUSIONS: Results showed that the type of body fat distribution of postmenopausal women is of android type. Considering side effects of this kind of distribution, necessary teachings about healthy eating, movement and exercises must be given to women of these ages. PMID:21589746

  3. Reversible Major Histocompatibility Complex I-Peptide Multimers Containing Ni2+-Nitrilotriacetic Acid Peptides and Histidine Tags Improve Analysis and Sorting of CD8+ T Cells*

    PubMed Central

    Schmidt, Julien; Guillaume, Philippe; Irving, Melita; Baumgaertner, Petra; Speiser, Daniel; Luescher, Immanuel F.

    2011-01-01

    MHC-peptide multimers containing biotinylated MHC-peptide complexes bound to phycoerythrin (PE) streptavidin (SA) are widely used for analyzing and sorting antigen-specific T cells. Here we describe alternative T cell-staining reagents that are superior to conventional reagents. They are built on reversible chelate complexes of Ni2+-nitrilotriacetic acid (NTA) with oligohistidines. We synthesized biotinylated linear mono-, di-, and tetra-NTA compounds using conventional solid phase peptide chemistry and studied their interaction with HLA-A*0201-peptide complexes containing a His6, His12, or 2×His6 tag by surface plasmon resonance on SA-coated sensor chips and equilibrium dialysis. The binding avidity increased in the order His6 < His12 < 2×His6 and NTA1 < NTA2 < NTA4, respectively, depending on the configuration of the NTA moieties and increased to picomolar KD for the combination of a 2×His6 tag and a 2×Ni2+-NTA2. We demonstrate that HLA-A2–2×His6-peptide multimers containing either Ni2+-NTA4-biotin and PE-SA- or PE-NTA4-stained influenza and Melan A-specific CD8+ T cells equal or better than conventional multimers. Although these complexes were highly stable, they very rapidly dissociated in the presence of imidazole, which allowed sorting of bona fide antigen-specific CD8+ T cells without inducing T cell death as well as assessment of HLA-A2-peptide monomer dissociation kinetics on CD8+ T cells. PMID:21990358

  4. Double Domain Swapping in Bovine Seminal RNase: Formation of Distinct N- and C-swapped Tetramers and Multimers with Increasing Biological Activities

    PubMed Central

    Gotte, Giovanni; Mahmoud Helmy, Alexander; Ercole, Carmine; Spadaccini, Roberta; Laurents, Douglas V.; Donadelli, Massimo; Picone, Delia

    2012-01-01

    Bovine seminal (BS) RNase, the unique natively dimeric member of the RNase super-family, represents a special case not only for its additional biological actions but also for the singular features of 3D domain swapping. The native enzyme is indeed a mixture of two isoforms: M = M, a dimer held together by two inter-subunit disulfide bonds, and MxM, 70% of the total, which, besides the two mentioned disulfides, is additionally stabilized by the swapping of its N-termini. When lyophilized from 40% acetic acid, BS-RNase oligomerizes as the super-family proto-type RNase A does. In this paper, we induced BS-RNase self-association and analyzed the multimers by size-exclusion chromatography, cross-linking, electrophoresis, mutagenesis, dynamic light scattering, molecular modelling. Finally, we evaluated their enzymatic and cytotoxic activities. Several BS-RNase domain-swapped oligomers were detected, including two tetramers, one exchanging only the N-termini, the other being either N- or C-swapped. The C-swapping event, confirmed by results on a BS-K113N mutant, has been firstly seen in BS-RNase here, and probably stabilizes also multimers larger than tetramers. Interestingly, all BS-RNase oligomers are more enzymatically active than the native dimer and, above all, they display a cytotoxic activity that definitely increases with the molecular weight of the multimers. This latter feature, to date unknown for BS-RNase, suggests again that the self-association of RNases strongly modulates their biological and potentially therapeutic properties. PMID:23071641

  5. Formation factor and the microscopic distribution of wetting phase in pore space of Berea sandstone

    SciTech Connect

    Schlueter, E.M.; Myer, L.R.; Cook, N.G.W.; Witherspoon, P.A.

    1992-11-01

    Experimental studies have been accomplished aimed at studying the formation factor of a partially saturated rock. The effective formation factors to an electrolyte solution of the pore spaces not occupied by a wetting raid (paraffin wax) have been measured at various saturations, after solidifying the wetting fluid in place. The experimental data is studied in light of the role of the pore structure on the wetting fluid invasion process with the aid of fluid distributions at each saturation regime, a complete rock pore cast, and its associated rock section. The effect of clay minerals on formation factor is studied. The surface conductance contribution of day minerals to overall electrical conductivity is assessed. The effect of partial hydrocarbon saturation on overall rock conductivity and on the Archei saturation exponent is discussed.

  6. Environmental Factors Controlling Ostracod Distribution on the Tibetan Plateau and Adjacent Areas

    NASA Astrophysics Data System (ADS)

    Boerner, N.; Pröttel, R.; Glodniok, S.; Söndgerath, D.; Naumann, K.; Frenzel, P.; Mischke, S.; Schwalb, A.

    2014-12-01

    Non-marine ostracods represent a reliable tool to reconstruct past climate conditions. The investigation of environmental tolerances of modern ostracod species is therefore vital to estimate past climate conditions based on fossil assemblages. To determine the climate range of individual ostracod species their modern geographical distribution is combined with climate data sets. The overlap of modern ecological tolerances of ostracod species found in a fossil assemblage yield information about past air temperatures [1]. In our study we establish ecological tolerances of species from the Tibetan Plateau and adjacent areas and indicate which environmental parameter is most important for species distribution. Therefore the point biserial correlation coefficient is applied on the species distribution of 34 taxa from 364 locations based on the presence/absence of species. We use a 0.93 km gridded climate database that pairs climate parameters with modern collection sites. In total we investigated the influence of 20 different environmental parameters, such as annual temperature amplitude, July and January temperatures, precipitation, salinity and altitude. The yearly temperature range is the most important factor defining the distribution for Candona candida and Fabaeformiscandona gyirongensis. The distribution of Eucypris mareotica is also influenced by the yearly temperature range, but in addition is restricted by low salinities. Species showing no correlation to temperature variations in their distribution were also identified. The distribution of Limnocythere inopinata and Heterocypris salina is restricted by the amount of precipitation, especially during winter months, and low salinities. On the other hand, Candona neglectaseems to be unaffected by any of the studied parameters and probably only is limited by extremely high salinities. The calculated mutual climate ranges of the investigated ostracod species will be applied to ostracod assemblage data from a long

  7. Imagens do céu ontem e hoje - um multimídia interativo de astronomia e uma nova exposição no MAST

    NASA Astrophysics Data System (ADS)

    Caretta, C. A.; Lima, F. P.; Requeijo, F.; Vieira, G. G.; Alves, F.; Valente, M. E. A.; de Almeida, R.; de Garcia, G. C.; Quixadá, A. C.

    2003-08-01

    "Imagens do Céu Ontem e Hoje" é o título de uma nova exposição que está sendo inaugurada no Museu de Astronomia e Ciências Afins (MCT), que inclui experimentos interativos, maquetes, réplicas e 8 terminais de computador com um multimídia interativo sobre Astronomia para consulta dos visitantes. O multimídia apresenta um conteúdo bastante extenso, que engloba quase todos os temas em Astronomia, consistindo numa fonte de divulgação e pesquisa para um público que vai das crianças até estudantes universitários. O conteúdo está distribuído em mais de 500 páginas de texto divididas em 4 módulos: "O Universo", "Espectroscopia", "Telescópios" e "Observando o Céu". Cada módulo é subdividido em 5 seções, em média, cada uma iniciada por uma animação que ilustra os temas a serem abordados na seção. Ao final da animação, uma lista de temas é apresentada sob o título "Saiba Mais". Para exemplificar, o módulo "O Universo" contém as seguintes seções: "O Universo visto pelo homem", "Conhecendo o Sistema Solar", "Indo além do Sistema Solar", "Nossa Galáxia, a Via-Láctea" e "Indo mais além, a imensidão do Universo". A seção "Conhecendo o Sistema Solar", por sua vez, tem os seguintes temas: "A origem do Sistema Solar", "O Sol", "Os planetas", "Satélites, asteróides, cometas e outros bichos..." e "O Sistema Solar em números". Cada texto é repleto de imagens, quadros, desenhos, esquemas, etc, além de passatempos ao final de cada seção, incluindo jogos interativos, quadrinhos e curiosidades, que auxiliam o aprendizado de forma divertida. Apresentamos neste trabalho as idéias gerais que permearam a produção da exposição, e uma viagem pelo multimídia para exemplificar sua estrutura e conteúdo. O multimídia será posteriormente disponibilizado para o público externo pela página eletrônica do MAst e/ou por intermédio de uma publicação comercial.

  8. Direct observation of multimer stabilization in the mechanical unfolding pathway of a protein undergoing oligomerization.

    PubMed

    Scholl, Zackary N; Yang, Weitao; Marszalek, Piotr E

    2015-02-24

    Understanding how protein oligomerization affects the stability of monomers in self-assembled structures is crucial to the development of new protein-based nanomaterials and protein cages for drug delivery. Here, we use single-molecule force spectroscopy (AFM-SMFS), protein engineering, and computer simulations to evaluate how dimerization and tetramerization affects the stability of the monomer of Streptavidin, a model homotetrameric protein. The unfolding force directly relates to the folding stability, and we find that monomer of Streptavidin is mechanically stabilized by 40% upon dimerization, and that it is stabilized an additional 24% upon tetramerization. We also find that biotin binding increases stability by another 50% as compared to the apo-tetrameric form. We used the distribution of unfolding forces to extract properties of the underlying energy landscape and found that the distance to the transition state is decreased and the barrier height is increased upon multimerization. Finally, we investigated the origin of the strengthening by ligand binding. We found that, rather than being strengthened through intramolecular contacts, it is strengthened due to the contacts provided by the biotin-binding loop that crosses the interface between the dimers. PMID:25639698

  9. Geological, Geophysical, and Stochastic Factors in Nepal's Gorkha Earthquake-Triggered Landslide Distribution

    NASA Astrophysics Data System (ADS)

    Kargel, J. S.; Shugar, D. H.; Haritashya, U. K.; Leonard, G. J.; Fielding, E. J.; Hudnut, K. W.; Jibson, R.; Collins, B. D.

    2015-12-01

    On 25 April 2015, a magnitude 7.8 earthquake struck Nepal. Subsequently many large aftershocks shook the region, including one of magnitude 7.3. Much damage and over 4300 landslides were triggered. The landslides were mapped by a volunteer group who self organized to undertake an emergency response to the earthquake disaster. The number of landslides is fewer than expected based on total released seismic energy. This may be because of lack of a surface rupture and possibly also because of high surface-wave attenuation due to rugged surface topography or to the geological and geophysical characteristics of the upper crust. The observed landslides were primarily in the southern half of the Himalaya in areas where the steepest slopes occur and where peak ground accelerations were relatively high. The landslides are also concentrated on the tectonically downdropped block. However, the distribution is complex and varies dramatically from valley to valley. Furthermore, different types of landslides are concentrated in different geologic materials, which suggests local factors control the valley-scale attenuation or amplification of seismic waves or the way wave disturbances couple to the local geologic materials. Across the earthquake-affected zone on the regional scale, wave attenuation and also net downdrop and uplift may also explain as much about the distribution of landslides as slopes and distance from large slips on the fault. We will offer the regional distribution results and some specific case studies to illustrate a set of possible controlling factors.

  10. Spatial Distribution of, and Risk Factors for, Opisthorchis viverrini Infection in Southern Lao PDR

    PubMed Central

    Forrer, Armelle; Sayasone, Somphou; Vounatsou, Penelope; Vonghachack, Youthanavanh; Bouakhasith, Dalouny; Vogt, Steffen; Glaser, Rüdiger; Utzinger, Jürg; Akkhavong, Kongsap; Odermatt, Peter

    2012-01-01

    Background Opisthorchis viverrini is a food-borne trematode species that might give rise to biliary diseases and the fatal cholangiocarcinoma. In Lao PDR, an estimated 2.5 million individuals are infected with O. viverrini, but epidemiological studies are scarce and the spatial distribution of infection remains to be determined. Our aim was to map the distribution of O. viverrini in southern Lao PDR, identify underlying risk factors, and predict the prevalence of O. viverrini at non-surveyed locations. Methodology A cross-sectional parasitological and questionnaire survey was carried out in 51 villages in Champasack province in the first half of 2007. Data on demography, socioeconomic status, water supply, sanitation, and behavior were combined with remotely sensed environmental data and fed into a geographical information system. Bayesian geostatistical models were employed to identify risk factors and to investigate the spatial pattern of O. viverrini infection. Bayesian kriging was utilized to predict infection risk at non-surveyed locations. Principal Findings The prevalence of O. viverrini among 3,371 study participants with complete data records was 61.1%. Geostatistical models identified age, Lao Loum ethnic group, educational attainment, occupation (i.e., rice farmer, fisherman, and animal breeder), and unsafe drinking water source as risk factors for infection. History of praziquantel treatment, access to sanitation, and distance to freshwater bodies were found to be protective factors. Spatial patterns of O. viverrini were mainly governed by environmental factors with predictive modeling identifying two different risk profiles: low risk of O. viverrini in the mountains and high risk in the Mekong corridor. Conclusions/Significance We present the first risk map of O. viverrini infection in Champasack province, which is important for spatial targeting of control efforts. Infection with O. viverrini appears to be strongly associated with exposure to the

  11. Charge density distributions and charge form factors of the N=82 and N=126 isotonic nuclei

    SciTech Connect

    Wang Zaijun; Fan Ying; Ren Zhongzhou

    2006-01-15

    Charge form factors for N=82 and N=126 isotonic nuclei are calculated with the relativistic eikonal approximation, in which the charge density distributions are from the relativistic mean-field theory. The variations of charge form factors with proton number are discussed in detail. It is found that the most sensitive parts of the charge form factors are those around the minimums and maximums. For an increasing proton number, the charge form factors near the extrema have an upward shift. As the protons increase and occupy a new shell, the minimums and maximums of the charge form factors could also have a significant inward shift. The results can be useful for the study of behaviors of valence-proton wave functions for such nuclei as can be considered as a core plus proton(s), and thus the proton-halo phenomenon. In addition, the results can also be useful for future electron-unstable nucleus scattering experiments and provide tests of the reliability of the relativistic mean-field theory for the unstable nuclei.

  12. Distribution of Hepatitis C Risk Factors and HCV Treatment Outcomes among Central Canadian Aboriginal

    PubMed Central

    Parmar, Parmvir; Corsi, Daniel J.; Cooper, Curtis

    2016-01-01

    Background. Aboriginal Canadians face many lifestyle risk factors for hepatitis C exposure. Methods. An analysis of Ottawa Hospital Viral Hepatitis Clinic (Ottawa, Canada) patients between January 2000 and August 2013 was performed. HCV infection risk factors and HCV treatment outcomes were assessed. Socioeconomic status markers were based on area-level indicators linked to postal codes using administrative databases. Results. 55 (2.8%) Aboriginal and 1923 (97.2%) non-Aboriginal patients were evaluated. Aboriginals were younger (45.6 versus 49.6 years, p < 0.01). The distribution of gender (63.6% versus 68.3% male), HIV coinfection (9.1% versus 8.1%), advanced fibrosis stage (29.2% versus 28.0%), and SVR (56.3% versus 58.9%) was similar between groups. Aboriginals had a higher number of HCV risk factors, (mean 4.2 versus 3.1, p < 0.001) with an odds ratio of 2.5 (95% confidence interval: 1.4–4.4) for having 4+ risk factors. This was not explained after adjustment for income, social deprivation, and poor housing. Aboriginal status was not related to SVR. Aboriginals interrupted therapy more often due to loss to follow-up, poor adherence, and substance abuse (25.0% versus 4.6%). Conclusion. Aboriginal Canadians have higher levels of HCV risk factors, even when adjusting for socioeconomic markers. Despite facing greater barriers to care, SVR rates were comparable with non-Aboriginals. PMID:27446875

  13. Factors affecting the distribution of hydrocarbon contaminants and hydrogeochemical parameters in a shallow sand aquifer.

    PubMed

    Lee, J Y; Cheon, J Y; Lee, K K; Lee, S Y; Lee, M H

    2001-07-01

    The distributions of hydrocarbon contaminants and hydrogeochemical parameters were investigated in a shallow sand aquifer highly contaminated with petroleum hydrocarbons leaked from solvent storage tanks. For these purposes, a variety of field investigations and studies were performed, which included installation of over 100 groundwater monitoring wells and piezometers at various depths, soil logging and analyses during well and piezometer installation, chemical analysis of groundwater, pump tests, and slug tests. Continuous water level monitoring at three selected wells using automatic data-logger and manual measuring at other wells were also conducted. Based on analyses of the various investigations and tests, a number of factors were identified to explain the distribution of the hydrocarbon contaminants and hydrogeochemical parameters. These factors include indigenous biodegradation, hydrostratigraphy, preliminary pump-and-treat remedy, recharge by rainfall, and subsequent water level fluctuation. The permeable sandy layer, in which the mean water table elevation is maintained, provided a dominant pathway for contaminant transport. The preliminary pump-and-treat action accelerated the movement of the hydrocarbon contaminants and affected the redox evolution pattern. Seasonal recharge by rain, together with indigenous biodegradation, played an important role in the natural attenuation of the petroleum hydrocarbons via mixing/dilution and biodegradation. The water level fluctuations redistributed the hydrocarbon contaminants by partitioning them into the soil and groundwater. The identified factors are not independent but closely inter-correlated. PMID:11475158

  14. Spatial distribution and controlling factors of sedimentary bodies in Jiaozhou Bay and Adjacent Sea Areas, Qingdao

    NASA Astrophysics Data System (ADS)

    Dong, Heping; Li, Guangxue; Li, Shuanglin; Li, Shaoquan; Li, Chun

    2011-06-01

    The distributions of thickness of unconsolidated Quaternary sedimentary layers in Jiaozhou Bay and Qingdao offshore area were studied by using 1079-km high-resolution shallow seismic profiles and drilling core data, and the factors controlling the Quaternary evolution were discussed. The results show that such thickness distributions resulted from the coactions of geologic structures and marine hydrodynamic conditions since the Holocene. The geologic structures controlled the slope deposit, proluvial and fluvial fillings since the late Pleistocene. Holocene marine hydrodynamics eroded away sediments at the bay mouth, and tides carried these eroded materials to the sides of the bay mouth and released them there, forming channel-ridge-alternating geomorphic features. During transgressive processes, the sea level rose rapidly, and insufficient sediment supply and tidal actions yielded the relict sediments in the east of Qingdao offshore area.

  15. FACTORS AFFECTING PHYTOPLANKTON DISTRIBUTION IN A DOUBLE-CELL SEWAGE LAGOON (1) (2).

    PubMed

    DeNoyelles, F

    1967-12-01

    The distribution of phyioplankton in a double-cell sewage lagoon at Hallam, Nebraska, was studied in relation to physical, chemical, and biological factors during the summer and fall of 1965. Sixteen species of algae were recorded in the first and more organically rich of the two physically similar ponds, with 28 species recorded in the second pond. Population sizes were always greater in the first pond due to reduced grazing during the summer and large quantities of ammonia-nitrogen during the fall. The dominant algal species in both ponds on nearly all sampling dates was Ankistrodesmus falcatus v. acicularis. Declines in this population occurred with high organic pollution and heavy grazing. Both ponds had severe reductions in algal numbers during late October due to heavy grazing by the rotifer Brachionus. The distribution of phytoplankton in the Hallam ponds is compared to that of other sewage ponds in the United States, and the general pattern which emerged is discussed. PMID:27065027

  16. [Distribution of 137Cs and relative influencing factors on typical karst sloping land].

    PubMed

    Zhang, Xiao-Nan; Wang, Ke-Lin; Zhang, Wei; Chen, Hong-Song; He, Xun-Yang; Zhang, Xin-Bao

    2009-11-01

    Based on the field survey and the analysis of a large number of soil samples, the distribution of 137 Cs and its influencing factors were studied using 137 Cs tracer technology on typical karst sloping land. The results indicate that the distribution of 137 Cs in soil profile in karst areas show the similar characteristics as that in non-karst areas, fitted an exponential pattern in forest soils and a uniform pattern in cultivated soils. In the sinkhole points in karst areas, 137 Cs exists in deep soil layers and its specific activity vary from 1.7 to 3.3 Bq/kg in soil layers above 45cm, suggesting the existing soil around karst sinkhole is mainly formed by the accumulation of erosion materials. The 137 Cs specific activity in the soil from two rock cracks are 16.8 Bq/kg and 37.6 Bq/kg respectively, which are much higher than that in the soil around the rock, this phenomenon indicates that bare rock is an important influencing factor for 137 Cs spatial movement. With the increment of altitude, the 137 Cs area activity exhibits an irregular fluctuation and evident spatial heterogeneity. On the forest land, the 137 Cs area activities which range from 299.4 to 1 592.6 Bq/m2 are highly positively correlated with the slope gradient and positively correlated with the altitude; while on the cultivated land, the 137 Cs area activities which range from 115.8 to 1478.6 Bq/m2 are negatively correlated with the slope gradient but negatively correlated with the altitude. Topography, geomorphology and human disturbance intensity are the key factors influencing 137 Cs spatial distribution. PMID:20063722

  17. Distributions of key exposure factors controlling the uptake of xenobiotic chemicals in an estuarine food web

    SciTech Connect

    Iannuzzi, T.J.; Harrington, N.W.; Shear, N.M.; Curry, C.L.; Carlson-Lynch, H.; Henning, M.H.; Su, S.H.; Rabbe, D.E.

    1996-11-01

    A critical evaluation of literature on the behavior, physiology, and ecology of common estuarine organisms was conducted in an attempt to develop probabilistic distributions for those variables that influence the uptake of xenobiotic chemicals from sediments, water, and food sources. The ranges, central tendencies, and distributions of several key parameter values were identified for dominant organisms from various trophic levels, including the polychaete Nereis virens, mummichog (Fundulus heteroclitus), blue crab (Callinectes sapidus), and striped bass (Morone saxatilis). The exposure factors of interest included ingestion rate for various food sources, growth rate, respiration rate, excretion rate, body weight, wet/dry weight ratio, lipid content, chemical assimilation efficiency, and food assimilation efficiency. These exposure factors are critical to the execution of mechanistic food web models, which, when properly calibrated, can be used to estimate tissue concentrations of nonionic chemicals in aquatic organisms based on knowledge of the bioenergetics and feeding interactions within a food web and the sediment and water concentrations of chemicals. In this article the authors describe the use of distributions for various exposure factors in the context of a mechanistic bioaccumulation model that is amenable to probabilistic analyses for multiple organisms within a food web. A case study is provided which compares the estimated versus measured concentrations of five polychlorinated biphenyl (PCB) congeners in a representative food web from the tidal portion of the Passaic River, New Jersey, USA. The results suggest that the model is accurate within an order of magnitude or less in estimating the bioaccumulation of PCBs in this food web without calibration. The results of a model sensitivity analysis suggest that the input parameters which most influence the output of the model are both chemical and organism specific.

  18. Factorization and the synthesis of optimal feedback gains for distributed parameter systems

    NASA Technical Reports Server (NTRS)

    Milman, Mark H.; Scheid, Robert E.

    1990-01-01

    An approach based on Volterra factorization leads to a new methodology for the analysis and synthesis of the optimal feedback gain in the finite-time linear quadratic control problem for distributed parameter systems. The approach circumvents the need for solving and analyzing Riccati equations and provides a more transparent connection between the system dynamics and the optimal gain. The general results are further extended and specialized for the case where the underlying state is characterized by autonomous differential-delay dynamics. Numerical examples are given to illustrate the second-order convergence rate that is derived for an approximation scheme for the optimal feedback gain in the differential-delay problem.

  19. Bidirectional scattering distribution function measurements from volume diffusers: correction factors and associated uncertainties.

    PubMed

    Germer, Thomas A

    2016-09-01

    We consider the effect of volume diffusion on measurements of the bidirectional scattering distribution function when a finite distance is used for the solid angle defining aperture. We derive expressions for correction factors that can be used when the reduced scattering coefficients and the index of refraction are known. When these quantities are not known, the expressions can be used to guide the assessment of measurement uncertainty. We find that some measurement geometries reduce the effect of volume diffusion compared to their reciprocal geometries. PMID:27607273

  20. Imaging shear stress distribution and evaluating the stress concentration factor of the human eye

    PubMed Central

    Joseph Antony, S.

    2015-01-01

    Healthy eyes are vital for a better quality of human life. Historically, for man-made materials, scientists and engineers use stress concentration factors to characterise the effects of structural non-homogeneities on their mechanical strength. However, such information is scarce for the human eye. Here we present the shear stress distribution profiles of a healthy human cornea surface in vivo using photo-stress analysis tomography, which is a non-intrusive and non-X-ray based method. The corneal birefringent retardation measured here is comparable to that of previous studies. Using this, we derive eye stress concentration factors and the directional alignment of major principal stress on the surface of the cornea. Similar to thermometers being used for monitoring the general health in humans, this report provides a foundation to characterise the shear stress carrying capacity of the cornea, and a potential bench mark for validating theoretical modelling of stresses in the human eye in future. PMID:25754336

  1. Imaging shear stress distribution and evaluating the stress concentration factor of the human eye

    NASA Astrophysics Data System (ADS)

    Joseph Antony, S.

    2015-03-01

    Healthy eyes are vital for a better quality of human life. Historically, for man-made materials, scientists and engineers use stress concentration factors to characterise the effects of structural non-homogeneities on their mechanical strength. However, such information is scarce for the human eye. Here we present the shear stress distribution profiles of a healthy human cornea surface in vivo using photo-stress analysis tomography, which is a non-intrusive and non-X-ray based method. The corneal birefringent retardation measured here is comparable to that of previous studies. Using this, we derive eye stress concentration factors and the directional alignment of major principal stress on the surface of the cornea. Similar to thermometers being used for monitoring the general health in humans, this report provides a foundation to characterise the shear stress carrying capacity of the cornea, and a potential bench mark for validating theoretical modelling of stresses in the human eye in future.

  2. Imaging shear stress distribution and evaluating the stress concentration factor of the human eye.

    PubMed

    Joseph Antony, S

    2015-01-01

    Healthy eyes are vital for a better quality of human life. Historically, for man-made materials, scientists and engineers use stress concentration factors to characterise the effects of structural non-homogeneities on their mechanical strength. However, such information is scarce for the human eye. Here we present the shear stress distribution profiles of a healthy human cornea surface in vivo using photo-stress analysis tomography, which is a non-intrusive and non-X-ray based method. The corneal birefringent retardation measured here is comparable to that of previous studies. Using this, we derive eye stress concentration factors and the directional alignment of major principal stress on the surface of the cornea. Similar to thermometers being used for monitoring the general health in humans, this report provides a foundation to characterise the shear stress carrying capacity of the cornea, and a potential bench mark for validating theoretical modelling of stresses in the human eye in future. PMID:25754336

  3. Factors limiting the intertidal distribution of the mangrove species Xylocarpus granatum

    USGS Publications Warehouse

    Allen, J.A.; Krauss, K.W.; Hauff, R.D.

    2003-01-01

    The tree species Xylocarpus granatum is commonly described as occurring in the upper intertidal zone of mangrove forests, but mature trees are occasionally found at lower elevations. In the Utwe River basin, on the Pacific island of Kosrae, we investigated the relative importance of several biotic and abiotic factors that may control the intertidal distribution of X. granatum. Factors we evaluated included differential seed predation across the lower, mid, and upper intertidal zones and seedling responses to salinity, tidal flooding, and shade. Seed predation was 22.4% over the first 34 days and varied little among zones or in gaps versus under the forest canopy. By day 161, there were still no differences in seed mortality, but a significant difference was found in seedling establishment, with much greater establishment in the upper intertidal plots. X. granatum seedlings in a greenhouse experiment exhibited greater growth in freshwater than seedlings in 23 ppt salinity, which is typical of salinity levels found in the mid intertidal zone in our field study sites in Micronesia, where mature X. granatum trees are generally absent. Seedlings grown in 23 ppt salinity, however, exhibited few visible signs of stress associated with patterns in growth. Seedlings grown in a simulated tidal flooding treatment (with 23 ppt salinity) also showed few signs of stress. Growth declined dramatically under 80% shade cloths, but there were few interactions of shading with either 23 ppt salinity or simulated tidal flooding. Differential seed predation is not likely to be the primary factor responsible for the intertidal distribution of X. granatum on Kosrae. However, seedling tolerance of flooding or salinity may be more important, especially relative to a potential contribution to secondary stress mortality. Other factors may ultimately prove to be more critical, such as physiological effects of salinity on seed germination, effects of tides on seed dispersal and rooting, or

  4. Physical factors driving intertidal macroalgae distribution: physiological stress of a dominant fucoid at its southern limit.

    PubMed

    Martínez, Brezo; Arenas, F; Rubal, M; Burgués, S; Esteban, R; García-Plazaola, I; Figueroa, F L; Pereira, R; Saldaña, L; Sousa-Pinto, I; Trilla, A; Viejo, R M

    2012-10-01

    Climate change is driving species range shifts worldwide. However, physiological responses related to distributional changes are not fully understood. Oceanographers have reported an increase in ocean temperature in the northwest Iberian Peninsula that is potentially related to the decline in some cold-temperate intertidal macroalgae in the Cantabrian Sea, namely Fucus serratus. Low tide stress could also play a role in this decline. We performed one mensurative (in situ) and two manipulative (in culture) experiments designed to evaluate the interactive effects of some physical factors. The first experiment analysed field response to low tide stress in marginal (mid-Cantabrian Sea and northern Portugal) versus central (Galicia) populations of F. serratus. Then a second experiment was performed that utilized either harsh or mild summer conditions of atmospheric temperature, irradiance, humidity, and wind velocity to compare the responses of individuals from one marginal and one central population to low tide stress. Finally, the combined effect of sea temperature and the other factors was evaluated to detect interactive effects. Changes in frond growth, maximal photosynthetic quantum yield (F(v)/F(m)), temperature, and desiccation were found. Three additive factors (solar irradiation, ocean and air temperatures) were found to drive F. serratus distribution, except under mildly humid conditions that ameliorated atmospheric thermal stress (two additive factors). Mid-Cantabrian Sea temperatures have recently increased, reaching the inhibitory levels suggested in this study of F. serratus. We also expect an additive secondary contribution of low tide stress to this species decline. On the northern Portugal coast, ocean warming plus low tide stress has not reached this species' inhibition threshold. No significant differential responses attributed to the population of origin were found. Mechanistic approaches that are designed to analyse the interactive effects of

  5. Pharmacokinetics and distribution of heparin-binding growth factor I (endothelial cell growth factor) in the rat

    SciTech Connect

    Rosengart, T.K.; Kuperschmid, J.P.; Maciag, T.; Clark, R.E.

    1989-02-01

    Heparin-binding growth factor I (HBGF I), previously designated as endothelial cell growth factor, is a potent mitogen for endothelial cells in vitro, which may prove useful for promoting endothelial regeneration in vivo. Analysis of the pharmacokinetics and organ distribution of HBGF I is necessary before use of HBGF I as a pharmacological agent. Consequently, pharmacological studies were carried out with (125I)HBGF I in the rat. Intravenous injections of HBGF I were given with or without heparin (2.5 units/ng HBGF I). Blood concentrations of HBGF I decreased by one half 17 seconds after HBGF I bolus. This time was prolonged to 60 seconds when HBGF I was injected with heparin. The elimination half-life of HBGF I was 14 minutes in the presence of heparin. The highest concentrations of HBGF I following intravenous bolus were found in kidney, liver, and spleen, and the lowest in fat and brain. Heparin increased HBGF I concentrations in blood and all organs measured except kidney, which was significantly decreased (p less than 0.01). Intact HBGF I was recoverable from blood 5 minutes following intravenous administration. HBGF I underwent near-complete proteolytic digestion after more prolonged ex vivo incubation with rat plasma, but HBGF I was protected from proteolysis when incubations were conducted in the presence of heparin. Thus, it is feasible that HBGF I can be administered as a pharmacological agent in the presence of heparin. Further studies assessing acceleration of in vivo endothelial growth using HBGF I with heparin appear warranted.

  6. Enhanced Detection of Antigen-Specific CD4+ T Cells Using Altered Peptide Flanking Residue Peptide–MHC Class II Multimers

    PubMed Central

    Holland, Christopher J.; Dolton, Garry; Scurr, Martin; Ladell, Kristin; Schauenburg, Andrea J.; Miners, Kelly; Madura, Florian; Sewell, Andrew K.; Price, David A.

    2015-01-01

    Fluorochrome-conjugated peptide–MHC (pMHC) class I multimers are staple components of the immunologist’s toolbox, enabling reliable quantification and analysis of Ag-specific CD8+ T cells irrespective of functional outputs. In contrast, widespread use of the equivalent pMHC class II (pMHC-II) reagents has been hindered by intrinsically weaker TCR affinities for pMHC-II, a lack of cooperative binding between the TCR and CD4 coreceptor, and a low frequency of Ag-specific CD4+ T cell populations in the peripheral blood. In this study, we show that peptide flanking regions, extending beyond the central nonamer core of MHC-II–bound peptides, can enhance TCR–pMHC-II binding and T cell activation without loss of specificity. Consistent with these findings, pMHC-II multimers incorporating peptide flanking residue modifications proved superior for the ex vivo detection, characterization, and manipulation of Ag-specific CD4+ T cells, highlighting an unappreciated feature of TCR–pMHC-II interactions. PMID:26553072

  7. Predicting the Distribution Pattern of Small Carnivores in Response to Environmental Factors in the Western Ghats

    PubMed Central

    Kalle, Riddhika; Ramesh, Tharmalingam; Qureshi, Qamar; Sankar, Kalyanasundaram

    2013-01-01

    Due to their secretive habits, predicting the pattern of spatial distribution of small carnivores has been typically challenging, yet for conservation management it is essential to understand the association between this group of animals and environmental factors. We applied maximum entropy modeling (MaxEnt) to build distribution models and identify environmental predictors including bioclimatic variables, forest and land cover type, topography, vegetation index and anthropogenic variables for six small carnivore species in Mudumalai Tiger Reserve. Species occurrence records were collated from camera-traps and vehicle transects during the years 2010 and 2011. We used the average training gain from forty model runs for each species to select the best set of predictors. The area under the curve (AUC) of the receiver operating characteristic plot (ROC) ranged from 0.81 to 0.93 for the training data and 0.72 to 0.87 for the test data. In habitat models for F. chaus, P. hermaphroditus, and H. smithii “distance to village” and precipitation of the warmest quarter emerged as some of the most important variables. “Distance to village” and aspect were important for V. indica while “distance to village” and precipitation of the coldest quarter were significant for H. vitticollis. “Distance to village”, precipitation of the warmest quarter and land cover were influential variables in the distribution of H. edwardsii. The map of predicted probabilities of occurrence showed potentially suitable habitats accounting for 46 km2 of the reserve for F. chaus, 62 km2 for V. indica, 30 km2 for P. hermaphroditus, 63 km2 for H. vitticollis, 45 km2 for H. smithii and 28 km2 for H. edwardsii. Habitat heterogeneity driven by the east-west climatic gradient was correlated with the spatial distribution of small carnivores. This study exemplifies the usefulness of modeling small carnivore distribution to prioritize and direct conservation planning for habitat specialists in

  8. Remote measurement of diesel locomotive emission factors and particle size distributions

    NASA Astrophysics Data System (ADS)

    Johnson, G. R.; Jayaratne, E. R.; Lau, J.; Thomas, V.; Juwono, A. M.; Kitchen, B.; Morawska, L.

    2013-12-01

    A technique for analysing exhaust emission plumes from unmodified locomotives under real world conditions is described and applied to the task of characterizing plumes from railway trains servicing an Australian shipping port. The method utilizes the simultaneous measurement, downwind of the railway line, of the following pollutants; particle number, PM2.5 mass fraction, SO2, NOx and CO2, with the last of these being used as an indicator of fuel combustion. Emission factors are then derived, in terms of number of particles and mass of pollutant emitted per unit mass of fuel consumed. Particle number size distributions are also presented. The practical advantages of the method are discussed including the capacity to routinely collect emission factor data for passing trains and to thereby build up a comprehensive real world database for a wide range of pollutants. Samples from 56 train movements were collected, analyzed and presented. The quantitative results for emission factors are: EF(N) = (1.7 ± 1) × 1016 kg-1, EF(PM2.5) = (1.1 ± 0.5) g kg-1, EF(NOx) = (28 ± 14) g kg-1, and EF(SO2) = (1.4 ± 0.4) g kg-1. The findings are compared with comparable previously published work. Statistically significant (p < α, α = 0.05) correlations within the group of locomotives sampled were found between the emission factors for particle number and both SO2 and NOx.

  9. Effective petroleum source rocks of the world: Stratigraphic distribution and controlling depositional factors

    SciTech Connect

    Klemme, H.D. ); Ulmishek, G.F. )

    1991-12-01

    Six stratigraphic intervals, representing one-third of Phanerozoic time, contain petroleum source rocks that have provided more than 90% of the world's discovered original reserves of oil and gas (in barrels of oil equivalent). The six intervals are (1) Silurian (generated 9% of the world's reserves), (2) Upper Devonian-Tournaisian (8% of reserves), (3) Pennsylvanian-Lower Permian (8% of reserves), (4) Upper Jurassic (25% of reserves), (5) middle Cretaceous (29% of reserves), and (6) Oligocene-Miocene (12.5% of reserves). This uneven distribution of source rocks vary from interval to interval. Maps that show facies, structural forms, and petroleum source rocks were prepared for this study. Analysis of the maps indicates that several primary factors controlled the areal distribution of source rocks, their geochemical type, and their effectiveness (i.e., the amounts of discovered original conventionally recoverable reserves of oil and gas generated by these rocks). These factors are geologic age, paleolatitude of the depositional areas, structural forms in which the deposition of source rocks occurred, and the evolution of biota. The maturation time of these source rocks demonstrates that majority of discovered oil and gas is very young; almost 70% of the world's original reserves of oil and gas has been generated since the Coniacian, and nearly 50% of the world's petroleum{sup 4} has been generated and trapped since the Oligocene.

  10. Environmental factors determining ammonia-oxidizing organism distribution and diversity in marine environments.

    PubMed

    Bouskill, Nicholas J; Eveillard, Damien; Chien, Diana; Jayakumar, Amal; Ward, Bess B

    2012-03-01

    Ammonia-oxidizing bacteria (AOB) and archaea (AOA) play a vital role in bridging the input of fixed nitrogen, through N-fixation and remineralization, to its loss by denitrification and anammox. Yet the major environmental factors determining AOB and AOA population dynamics are little understood, despite both groups having a wide environmental distribution. This study examined the relative abundance of both groups of ammonia-oxidizing organisms (AOO) and the diversity of AOA across large-scale gradients in temperature, salinity and substrate concentration and dissolved oxygen. The relative abundance of AOB and AOA varied across environments, with AOB dominating in the freshwater region of the Chesapeake Bay and AOA more abundant in the water column of the coastal and open ocean. The highest abundance of the AOA amoA gene was recorded in the oxygen minimum zones (OMZs) of the Eastern Tropical South Pacific (ETSP) and the Arabian Sea (AS). The ratio of AOA : AOB varied from 0.7 in the Chesapeake Bay to 1600 in the Sargasso Sea. Relative abundance of both groups strongly correlated with ammonium concentrations. AOA diversity, as determined by phylogenetic analysis of clone library sequences and archetype analysis from a functional gene DNA microarray, detected broad phylogenetic differences across the study sites. However, phylogenetic diversity within physicochemically congruent stations was more similar than would be expected by chance. This suggests that the prevailing geochemistry, rather than localized dispersal, is the major driving factor determining OTU distribution. PMID:22050634

  11. Socioeconomic and Ecological Factors Influencing Aedes aegypti Prevalence, Abundance, and Distribution in Dhaka, Bangladesh

    PubMed Central

    Dhar-Chowdhury, Parnali; Haque, C. Emdad; Lindsay, Robbin; Hossain, Shakhawat

    2016-01-01

    This study examined household risk factors and prevalence, abundance, and distribution of immature Aedes aegypti and Aedes albopictus, and their association with socioeconomic and ecological factors at urban zonal and household levels in the city of Dhaka, Bangladesh. During the 2011 monsoon, 826 households in 12 randomly selected administrative wards were surveyed for vector mosquitoes. Results revealed that the abundance and distribution of immature Ae. aegypti and Ae. albopictus, and pupae-per-person indices did not vary significantly among the zones with varied socioeconomic status. Of 35 different types of identified wet containers, 30 were infested, and among the 23 pupae-positive container types, nine were defined as the “most productive” for pupae including: disposable plastic containers (12.2% of 550), sealable plastic barrels (12.0%), tires (10.4%), abandoned plastic buckets (9.6%), flower tub and trays (8.5%), refrigerator trays (6.5%), plastic bottles (6.4%), clay pots (4.9%), and water tanks (1.6%). When the function of the containers was assessed, ornamental, discarded, and household repairing and reconstruction-related container categories were found significantly associated with the number of pupae in the households. The purpose of storing water and income variables were significant predictors of possession of containers that were infested by vector mosquitoes. PMID:27022149

  12. Socioeconomic and Ecological Factors Influencing Aedes aegypti Prevalence, Abundance, and Distribution in Dhaka, Bangladesh.

    PubMed

    Dhar-Chowdhury, Parnali; Haque, C Emdad; Lindsay, Robbin; Hossain, Shakhawat

    2016-06-01

    This study examined household risk factors and prevalence, abundance, and distribution of immature Aedes aegypti and Aedes albopictus, and their association with socioeconomic and ecological factors at urban zonal and household levels in the city of Dhaka, Bangladesh. During the 2011 monsoon, 826 households in 12 randomly selected administrative wards were surveyed for vector mosquitoes. Results revealed that the abundance and distribution of immature Ae. aegypti and Ae. albopictus, and pupae-per-person indices did not vary significantly among the zones with varied socioeconomic status. Of 35 different types of identified wet containers, 30 were infested, and among the 23 pupae-positive container types, nine were defined as the "most productive" for pupae including: disposable plastic containers (12.2% of 550), sealable plastic barrels (12.0%), tires (10.4%), abandoned plastic buckets (9.6%), flower tub and trays (8.5%), refrigerator trays (6.5%), plastic bottles (6.4%), clay pots (4.9%), and water tanks (1.6%). When the function of the containers was assessed, ornamental, discarded, and household repairing and reconstruction-related container categories were found significantly associated with the number of pupae in the households. The purpose of storing water and income variables were significant predictors of possession of containers that were infested by vector mosquitoes. PMID:27022149

  13. Protein Adsorption Patterns and Analysis on IV Nanoemulsions—The Key Factor Determining the Organ Distribution

    PubMed Central

    Keck, Cornelia M.; Jansch, Mirko; Müller, Rainer H.

    2012-01-01

    Intravenous nanoemulsions have been on the market for parenteral nutrition since the 1950s; meanwhile, they have also been used successfully for IV drug delivery. To be well tolerable, the emulsions should avoid uptake by the MPS cells of the body; for drug delivery, they should be target-specific. The organ distribution is determined by the proteins adsorbing them after injection from the blood (protein adsorption pattern), typically analyzed by two-dimensional polyacrylamide gel electrophoresis, 2-D PAGE. The article reviews the 2-D PAGE method, the analytical problems to be faced and the knowledge available on how the composition of emulsions affects the protein adsorption patterns, e.g., the composition of the oil phase, stabilizer layer and drug incorporation into the interface or oil core. Data were re-evaluated and compared, and the implications for the in vivo distribution are discussed. Major results are that the interfacial composition of the stabilizer layer is the main determining factor and that this composition can be modulated by simple processes. Drug incorporation affects the pattern depending on the localization of the drug (oil core versus interface). The data situation regarding in vivo effects is very limited; mainly, it has to be referred to in the in vivo data of polymeric nanoparticles. As a conclusion, determination of the protein adsorption patterns can accelerate IV nanoemulsion formulation development regarding optimized organ distribution and related pharmacokinetics. PMID:24300396

  14. Phylogeography of the Marine Otter (Lontra felina): historical and contemporary factors determining its distribution.

    PubMed

    Vianna, Juliana A; Ayerdi, Paula; Medina-Vogel, Gonzalo; Mangel, Jeffrey C; Zeballos, Horacio; Apaza, Manuel; Faugeron, Sylvain

    2010-01-01

    The evolutionary history of a species can be revealed by phylogeographical analysis; nevertheless, not only historical but also contemporary processes can imprint on the distribution of genetic diversity. We report on the phylogeny of Lontra ssp. in South America, and the role of spatial heterogeneity in shaping the distribution and population structure of the endangered marine otter, Lontra felina. Analyzing a total of 2261 bp of mitochondrial DNA (mtDNA) revealed the recent divergence of L. felina from L. provocax. A strong population structure (Φ(st) = 0.83, P < 0.0001) and a significant pattern of isolation by distance were described for L. felina (n = 168) across a wide geographical distribution (13°53'S to 43°36'S). Lontra felina mtDNA phylogeny is composed of 2 main clades: a clade from Peru and another composed of Chilean haplotypes. Northern populations show different divergent lineages and higher genetic diversity when compared with more recently colonized southern populations. Furthermore, long sandy beaches seem to act as barriers to dispersal, creating 2 evolutionary significant units in agreement with subspecies previous description, and at least 5 different management units (MUs). At a fine spatial scale, the size of rocky seashore patches, the distance between patches and anthropogenic factors also play important roles in species gene flow. PMID:20688888

  15. Virtuality Distributions in application to gamma gamma* to pi^0 Transition Form Factor at Handbag Level

    SciTech Connect

    Radyushkin, Anatoly V.

    2014-07-01

    We outline basics of a new approach to transverse momentum dependence in hard processes. As an illustration, we consider hard exclusive transition process gamma*gamma -> to pi^0 at the handbag level. Our starting point is coordinate representation for matrix elements of operators (in the simplest case, bilocal O(0,z)) describing a hadron with momentum p. Treated as functions of (pz) and z^2, they are parametrized through a virtuality distribution amplitude (VDA) Phi (x, sigma), with x being Fourier-conjugate to (pz) and sigma Laplace-conjugate to z^2. For intervals with z^+=0, we introduce transverse momentum distribution amplitude (TMDA) Psi (x, k_\\perp), and write it in terms of VDA Phi (x, \\sigma). The results of covariant calculations, written in terms of Phi (x sigma) are converted into expressions involving Psi (x, k_\\perp. Starting with scalar toy models, we extend the analysis onto the case of spin-1/2 quarks and QCD. We propose simple models for soft VDAs/TMDAs, and use them for comparison of handbag results with experimental (BaBar and BELLE) data on the pion transition form factor. We also discuss how one can generate high-k_\\perp tails from primordial soft distributions.

  16. [Vertical distribution of fuels in Pinus yunnanensis forest and related affecting factors].

    PubMed

    Wang, San; Niu, Shu-Kui; Li, De; Wang, Jing-Hua; Chen, Feng; Sun, Wu

    2013-02-01

    In order to understand the effects of fuel loadings spatial distribution on forest fire kinds and behaviors, the canopy fuels and floor fuels of Pinus yunnanensis forests with different canopy density, diameter at breast height (DBH), tree height, and stand age and at different altitude, slope grade, position, and aspect in Southwest China were taken as test objects, with the fuel loadings and their spatial distribution characteristics at different vertical layers compared and the fire behaviors in different stands analyzed. The relationships between the fuel loadings and the environmental factors were also analyzed by canonical correspondence analysis (CCA). In different stands, there existed significant differences in the vertical distribution of fuels. Pinus yunnanensis-Qak-Syzygium aromaticum, Pinus yunnanensis-oak, and Pinus yunnanensis forests were likely to occur floor fire but not crown fire, while Pinus yunnanensis-Platycladus orientalis, Pinus yunnanensis-Keteleeria fortune, and Keteleeria fortune-Pinus yunnanensis were not only inclined to occur floor fire, but also, the floor fire could be easily transformed into crown fire. The crown fuels were mainly affected by the stand age, altitude, DBH, and tree height, while the floor fuels were mainly by the canopy density, slope grade, altitude, and stand age. PMID:23705375

  17. Factors Controlling Droplet Concentration and Size Distribution in Clouds over Dominica

    NASA Astrophysics Data System (ADS)

    Russotto, R. D.; Storelvmo, T.; Smith, R. B.

    2011-12-01

    Since precipitation in convective, tropical clouds, and the impact of these clouds on Earth's radiation budget, are dependent on the concentration and size distribution of the water droplets that make up the clouds, we are interested in understanding the factors controlling the droplet concentration and size distribution in these clouds. Previous studies from field campaigns have led to contradictory conclusions, with some research pointing to updraft velocity as the most influential factor, and other studies pointing to aerosol concentration. The 2011 Dominica Experiment (DOMEX) field campaign provides a wealth of data with which to study this problem, and to test existing models of droplet activation and growth; these data include aerosol and cloud droplet concentrations and size distributions, and wind speed measurements, from research flights above and upwind of the island of Dominica, as well as precipitation data from rain gauges installed on the island. Over 17 DOMEX research flights, cloud droplet concentrations averaged over flight legs above the island were positively correlated with aerosol concentrations from legs flown upwind of the island at 305 m altitude, while cloud droplet mean diameters were negatively correlated with oversea aerosol concentrations, supporting the idea that higher aerosol concentrations (if they are water soluble aerosols, such as sea salt) result in more droplets becoming activated and not growing as large. Meanwhile, average horizontal wind speeds in the oversea legs were negatively correlated with droplet concentrations in clouds over the island, and positively correlated with the mean diameter, the opposite of what would be expected if stronger convection accompanied the higher horizontal wind speeds. The horizontal wind speeds were also negatively correlated with the aerosol concentrations, especially at very low wind speeds, suggesting that the negative impact of wind speed on droplet concentration may have been due to a

  18. Distribution Patterns of Infection with Multiple Types of Human Papillomaviruses and Their Association with Risk Factors

    PubMed Central

    Soto-De Leon, Sara; Camargo, Milena; Sanchez, Ricardo; Munoz, Marina; Perez-Prados, Antonio; Purroy, Antonio; Patarroyo, Manuel Elkin; Patarroyo, Manuel Alfonso

    2011-01-01

    Background Infection with multiple types of human papillomavirus (HPV) is one of the main risk factors associated with the development of cervical lesions. In this study, cervical samples collected from 1,810 women with diverse sociocultural backgrounds, who attended to their cervical screening program in different geographical regions of Colombia, were examined for the presence of cervical lesions and HPV by Papanicolau testing and DNA PCR detection, respectively. Principal Findings The negative binomial distribution model used in this study showed differences between the observed and expected values within some risk factor categories analyzed. Particularly in the case of single infection and coinfection with more than 4 HPV types, observed frequencies were smaller than expected, while the number of women infected with 2 to 4 viral types were higher than expected. Data analysis according to a negative binomial regression showed an increase in the risk of acquiring more HPV types in women who were of indigenous ethnicity (+37.8%), while this risk decreased in women who had given birth more than 4 times (−31.1%), or were of mestizo (−24.6%) or black (−40.9%) ethnicity. Conclusions According to a theoretical probability distribution, the observed number of women having either a single infection or more than 4 viral types was smaller than expected, while for those infected with 2–4 HPV types it was larger than expected. Taking into account that this study showed a higher HPV coinfection rate in the indigenous ethnicity, the role of underlying factors should be assessed in detail in future studies. PMID:21379574

  19. Soil carbon distribution in Alaska in relation to soil-forming factors

    USGS Publications Warehouse

    Johnson, K.D.; Harden, J.; McGuire, A.D.; Bliss, N.B.; Bockheim, J.G.; Clark, M.; Nettleton-Hollingsworth, T.; Jorgenson, M.T.; Kane, E.S.; Mack, M.; O'Donnell, J.; Ping, C.-L.; Schuur, E.A.G.; Turetsky, M.R.; Valentine, D.W.

    2011-01-01

    The direction and magnitude of soil organic carbon (SOC) changes in response to climate change remain unclear and depend on the spatial distribution of SOC across landscapes. Uncertainties regarding the fate of SOC are greater in high-latitude systems where data are sparse and the soils are affected by sub-zero temperatures. To address these issues in Alaska, a first-order assessment of data gaps and spatial distributions of SOC was conducted from a recently compiled soil carbon database. Temperature and landform type were the dominant controls on SOC distribution for selected ecoregions. Mean SOC pools (to a depth of 1-m) varied by three, seven and ten-fold across ecoregion, landform, and ecosystem types, respectively. Climate interactions with landform type and SOC were greatest in the uplands. For upland SOC there was a six-fold non-linear increase in SOC with latitude (i.e., temperature) where SOC was lowest in the Intermontane Boreal compared to the Arctic Tundra and Coastal Rainforest. Additionally, in upland systems mineral SOC pools decreased as climate became more continental, suggesting that the lower productivity, higher decomposition rates and fire activity, common in continental climates, interacted to reduce mineral SOC. For lowland systems, in contrast, these interactions and their impacts on SOC were muted or absent making SOC in these environments more comparable across latitudes. Thus, the magnitudes of SOC change across temperature gradients were non-uniform and depended on landform type. Additional factors that appeared to be related to SOC distribution within ecoregions included stand age, aspect, and permafrost presence or absence in black spruce stands. Overall, these results indicate the influence of major interactions between temperature-controlled decomposition and topography on SOC in high-latitude systems. However, there remains a need for more SOC data from wetlands and boreal-region permafrost soils, especially at depths > 1 m in order

  20. Environmental risk factors and hotspot analysis of dengue distribution in Pakistan.

    PubMed

    Khalid, Bushra; Ghaffar, Abdul

    2015-11-01

    This study is an attempt to find out the factors responsible for sudden dengue outbreak in different cities of Pakistan during 2011. For this purpose, spatio-temporal distribution of dengue in Islamabad, Rawalpindi, Lahore, and Karachi has been taken into account. According to the available data, the factors responsible for this spread includes climate covariates like rainfall, temperature, and wind speed; social covariates like population, and area of locality, and environmental risk factors like drainage pattern and geo-hydrological conditions. Reported dengue cases from localities and Shuttle Radar Topography Mission (SRTM) 90 m digital elevation model (DEM) of study areas have been processed for hotspots, regression model and stream density in the localities of high dengue incidence. The relationship of daily dengue incidence with climate covariates during the months of July-October of the study year is analyzed. Results show that each dry spell of 2-4 days provides suitable conditions for the development and survival of dengue vectors during the wet months of July and August in the areas of high stream density and population. Very few cases have been reported in July while higher number of cases reported in the months of August, September, until late October. Hotspot analysis highlights the areas of high dengue incidence while regression analysis shows the relationship between the population and the areas of localities with the dengue incidence. PMID:25869291

  1. Environmental risk factors and hotspot analysis of dengue distribution in Pakistan

    NASA Astrophysics Data System (ADS)

    Khalid, Bushra; Ghaffar, Abdul

    2015-11-01

    This study is an attempt to find out the factors responsible for sudden dengue outbreak in different cities of Pakistan during 2011. For this purpose, spatio-temporal distribution of dengue in Islamabad, Rawalpindi, Lahore, and Karachi has been taken into account. According to the available data, the factors responsible for this spread includes climate covariates like rainfall, temperature, and wind speed; social covariates like population, and area of locality, and environmental risk factors like drainage pattern and geo-hydrological conditions. Reported dengue cases from localities and Shuttle Radar Topography Mission (SRTM) 90 m digital elevation model (DEM) of study areas have been processed for hotspots, regression model and stream density in the localities of high dengue incidence. The relationship of daily dengue incidence with climate covariates during the months of July-October of the study year is analyzed. Results show that each dry spell of 2-4 days provides suitable conditions for the development and survival of dengue vectors during the wet months of July and August in the areas of high stream density and population. Very few cases have been reported in July while higher number of cases reported in the months of August, September, until late October. Hotspot analysis highlights the areas of high dengue incidence while regression analysis shows the relationship between the population and the areas of localities with the dengue incidence.

  2. Mining heart disease risk factors in clinical text with named entity recognition and distributional semantic models.

    PubMed

    Urbain, Jay

    2015-12-01

    We present the design, and analyze the performance of a multi-stage natural language processing system employing named entity recognition, Bayesian statistics, and rule logic to identify and characterize heart disease risk factor events in diabetic patients over time. The system was originally developed for the 2014 i2b2 Challenges in Natural Language in Clinical Data. The system's strengths included a high level of accuracy for identifying named entities associated with heart disease risk factor events. The system's primary weakness was due to inaccuracies when characterizing the attributes of some events. For example, determining the relative time of an event with respect to the record date, whether an event is attributable to the patient's history or the patient's family history, and differentiating between current and prior smoking status. We believe these inaccuracies were due in large part to the lack of an effective approach for integrating context into our event detection model. To address these inaccuracies, we explore the addition of a distributional semantic model for characterizing contextual evidence of heart disease risk factor events. Using this semantic model, we raise our initial 2014 i2b2 Challenges in Natural Language of Clinical data F1 score of 0.838 to 0.890 and increased precision by 10.3% without use of any lexicons that might bias our results. PMID:26305514

  3. Distribution of Third-Stage Length and Risk Factors for Its Prolongation.

    PubMed

    Shinar, Shiri; Shenhav, Michael; Maslovitz, Sharon; Many, Ariel

    2016-08-01

    Introduction The aim of our study was to demonstrate the distribution of an uncomplicated third stage and to determine the optimal time for manual intervention. Risk factors for a prolonged third stage were studied. Materials and Methods Computerized data of all vaginal deliveries at our L&D unit from 2010 to 2014 were obtained. Cases of complete and spontaneous placental separation were extracted for further analysis. Cases necessitating manual removal of the placenta due to immediate postpartum hemorrhage (PPH) were also excluded. Patient demographics, obstetrical history, course of delivery, and delivery outcome were assessed, and risk factors for a prolonged third stage were analyzed. Results There were 31,226 vaginal deliveries during the study period. Of these, 25,160 deliveries met inclusion criteria. The median third-stage length was 12 minutes. Within 30 minutes 97% of the placentas separated spontaneously. Independent risk factors for a third stage > 30 minutes included older maternal age, primiparity, history of abortions, twin gestation, and intrapartum fever. Conclusion The average time for third stage is < 15 minutes with 97% occurring by 30 minutes and 100% by 60 minutes. In the absence of PPH, it is clinically prudent to perform manual removal after 30 minutes. PMID:27135956

  4. Factors Which Impact the Distribution of Leadership for an ICT Reform: Expertise vis-a-vis Formal Role?

    ERIC Educational Resources Information Center

    Ho, Jeanne Marie; Ng, David

    2012-01-01

    This study examined the process of Information Communication Technology reform in a Singapore school. The focus was on distributed leadership actions, and the factors which enabled and constrained the distribution of leadership. This study adopted a naturalistic inquiry approach, involving the case study of a school. The study found that…

  5. Dynamic Distribution and Interaction of the Arabidopsis SRSF1 Subfamily Splicing Factors.

    PubMed

    Stankovic, Nancy; Schloesser, Marie; Joris, Marine; Sauvage, Eric; Hanikenne, Marc; Motte, Patrick

    2016-02-01

    Ser/Arg-rich (SR) proteins are essential nucleus-localized splicing factors. Our prior studies showed that Arabidopsis (Arabidopsis thaliana) RSZ22, a homolog of the human SRSF7 SR factor, exits the nucleus through two pathways, either dependent or independent on the XPO1 receptor. Here, we examined the expression profiles and shuttling dynamics of the Arabidopsis SRSF1 subfamily (SR30, SR34, SR34a, and SR34b) under control of their endogenous promoter in Arabidopsis and in transient expression assay. Due to its rapid nucleocytoplasmic shuttling and high expression level in transient assay, we analyzed the multiple determinants that regulate the localization and shuttling dynamics of SR34. By site-directed mutagenesis of SR34 RNA-binding sequences and Arg/Ser-rich (RS) domain, we further show that functional RRM1 or RRM2 are dispensable for the exclusive protein nuclear localization and speckle-like distribution. However, mutations of both RRMs induced aggregation of the protein whereas mutation in the RS domain decreased the stability of the protein and suppressed its nuclear accumulation. Furthermore, the RNA-binding motif mutants are defective for their export through the XPO1 (CRM1/Exportin-1) receptor pathway, but retain nucleocytoplasmic mobility. We performed a yeast two hybrid screen with SR34 as bait and discovered SR45 as a new interactor. SR45 is an unusual SR splicing factor bearing two RS domains. These interactions were confirmed in planta by FLIM-FRET and BiFC and the roles of SR34 domains in protein-protein interactions were further studied. Altogether, our report extends our understanding of shuttling dynamics of Arabidopsis SR splicing factors. PMID:26697894

  6. Processes and their explanatory factors governing distribution of organic phosphorous pools in lake sediments.

    PubMed

    Lü, Changwei; He, Jiang; Zuo, Le; Vogt, Rolf D; Zhu, Liang; Zhou, Bin; Mohr, Christian W; Guan, Rui; Wang, Weiying; Yan, Daohao

    2016-02-01

    The amount of organic phosphorus (OP) and its distribution among different pools in lake sediments depends on biotic and abiotic processes driving the OP fractionation. Key environmental factors governing these transformations processes between OP fractionations in sediments were studied on the basis of geochemical characteristics of OP pools in relation to environmental factors in the sediments. The results illustrate that the factors influencing the accumulation or depletion of different OP pools were intrinsically dependent on the composition of the deposited organic matter (OM). During the mineralization of the OM the microorganisms excrete the enzyme alkaline phosphatase, accelerating the OP hydrolysis, and thereby setting the grounds for the bacterially-mediated oxidation of OM. There are two main degradation products of the labile OP pool (LOP) and the moderately labile OP pool (MLOP): Either the OP is transformed to a dissolved organic or inorganic P form, and thereby released to water column, or OP is transformed to a non-labile OP pool and stored in the sediments. A comparative study showed that oxy-hydroxides of iron (Fe) and aluminum (Al) only played an important role in influencing OP fractionation in Lake Wuliangsuhai, while the complexation reactions of OP with calcium ions and sorption to its minerals are key factors governing the OP fractionation in the two alkaline lakes. It is worth noting that a significant correlation between the Fe-P pool and the pools of LOP and MLOP indicates that the degradation of the rather labile OP pools are highly dependent on the iron redox reaction. PMID:26688248

  7. On-road emission factor distributions of individual diesel vehicles in and around Beijing, China

    NASA Astrophysics Data System (ADS)

    Wang, Xing; Westerdahl, Dane; Wu, Ye; Pan, Xiaochuan; Zhang, K. Max

    2011-01-01

    This paper reports findings of a recent field study that characterized the on-road emissions of individual diesel vehicles in and around Beijing, China during November and December of 2009. We successfully sampled 230 individual trucks on 4 major expressways around the city as well as 57 individual buses in the city using refined mobile chasing techniques and fast response instruments. Emission factors (EF) for carbon monoxide (CO), black carbon (BC) and particulate matter with diameters less than 0.5 μm (PM 0.5) are derived from the measurements, which are consistent with the results from laboratory dynamometer tests. The PM 0.5 number emission factor distributions demonstrate consistent bimodal modes with peaks around 10 nm and 80 nm, while the mass emission factor distributions demonstrate a unimodal maximum around 110 nm for a majority of the trucks. The BC emissions are shown to be highly correlated with the mass emission of particles with 100-250 nm diameters, which are in good agreement with the results from previous studies. A number of important policy implications are discussed based on the results from this study. First, we identified "heavy emitters" in the on-road fleet we encountered, finding that 5% of diesel trucks in this sample are responsible for 50% of total BC emissions, and 20% of the trucks are responsible for 50% CO and PM 0.5 number emissions, 60% PM 0.5 mass emissions and over 70% of BC emissions. This suggests that emissions control programs should include identifying and removing heavy emitters from the road or improving their emissions. Second, the BC and PM 0.5 number emission factors of trucks registered in regions outside Beijing are significantly higher than those of Beijing-registered trucks, suggesting that improving engine and fuel standards in Beijing alone is not sufficient in reducing the traffic-related air pollution in Beijing. Third, the significantly lower emissions from Euro IV and CNG buses compared to the Euro II and

  8. Factors influencing the distribution of epibenthic megafauna across the Peruvian oxygen minimum zone

    NASA Astrophysics Data System (ADS)

    Mosch, Thomas; Sommer, Stefan; Dengler, Marcus; Noffke, Anna; Bohlen, Lisa; Pfannkuche, Olaf; Liebetrau, Volker; Wallmann, Klaus

    2012-10-01

    Current de-oxygenation of the oceans is associated with severe habitat loss and distinct changes in the species composition of bentho-pelagic communities. We investigated the distributions of epibenthic megafauna across the Peruvian OMZ (11°S) at water depths ranging from ˜80 to 1000 m water depth using sea floor images. Likely controls of distributions were adressed by combining the abundances of major groups with geochemical parameters and sea-floor topography. In addition to bottom-water oxygen levels and organic-carbon availability, particular emphasis is laid on the effects of local hydrodynamics. Beside the occurrence of microbial mats at the shelf and upper slope, distinct zones of highly abundant megafauna, dominated by gastropods (900 ind. m-2), ophiuroids (140 ind. m-2), and pennatulaceans (20 ind. m-2), were observed at the lower boundary of the OMZ. Their distribution extended from 460 m water depth (O2 levels < 2 μM), where gastropods were abundant, to 680 m (O2 ˜6 μM) where epifaunal abundances declined sharply. Bottom water O2 represents a major factor that limits the ability of metazoans to invade deeply into the OMZ where they could have access to labile organic carbon. However, depending on their feeding mode, the distribution of organisms appeared to be related to local hydrodynamics caused by the energy dissipation of incipient internal M2 tides affecting the suspension, transport and deposition of food particles. This was particularly evident in certain sections of the investigated transect. At these potentially critical sites, energy dissipation of internal tides is associated with high bottom shear stress and high turbulences and coincides with elevated turbidity levels in the benthic boundary layer, increased Zr/Al-ratios, low sedimentation rates as well as a shift in the grain size towards coarser particles. In or near such areas, abundant suspension-feeding organisms, such as ophiuroids, pennatulaceans, and tunicates were present

  9. Distribution of {Omega}{sub k} from the scale-factor cutoff measure

    SciTech Connect

    De Simone, Andrea; Salem, Michael P.

    2010-04-15

    Our Universe may be contained in one among a diverging number of bubbles that nucleate within an eternally inflating multiverse. A promising measure to regulate the diverging spacetime volume of such a multiverse is the scale-factor cutoff, one feature of which is bubbles are not rewarded for having a longer duration of slow-roll inflation. Thus, depending on the landscape distribution of the number of e-folds of inflation among bubbles like ours, we might hope to measure spatial curvature. We study a recently proposed cartoon model of inflation in the landscape and find a reasonable chance (about 10%) that the curvature in our Universe is well above the value expected from cosmic variance. Anthropic selection does not strongly select for curvature as small as is observed (relative somewhat larger values), meaning the observational bound on curvature can be used to rule out landscape models that typically give too little inflation.

  10. Feature enhancement of reverberant speech by distribution matching and non-negative matrix factorization

    NASA Astrophysics Data System (ADS)

    Keronen, Sami; Kallasjoki, Heikki; Palomäki, Kalle J.; Brown, Guy J.; Gemmeke, Jort F.

    2015-12-01

    This paper describes a novel two-stage dereverberation feature enhancement method for noise-robust automatic speech recognition. In the first stage, an estimate of the dereverberated speech is generated by matching the distribution of the observed reverberant speech to that of clean speech, in a decorrelated transformation domain that has a long temporal context in order to address the effects of reverberation. The second stage uses this dereverberated signal as an initial estimate within a non-negative matrix factorization framework, which jointly estimates a sparse representation of the clean speech signal and an estimate of the convolutional distortion. The proposed feature enhancement method, when used in conjunction with automatic speech recognizer back-end processing, is shown to improve the recognition performance compared to three other state-of-the-art techniques.

  11. Tissue distribution of the guinea-pig decay-accelerating factor.

    PubMed Central

    Nishikawa, K; Matsuo, S; Tamai, H; Okada, N; Okada, H

    1998-01-01

    MCA44 is a monoclonal antibody (mAb) to guinea-pig decay-accelerating factor (DAF) and, using this mAb, tissue distribution of guinea-pig DAF was studied by immunofluorescence. Guinea-pig DAF was found to be expressed not only on the vascular endothelium but also on different types of cells, such as the tubular epithelium of the kidney, epidermal cells of the skin and synovial lining cells. As there was no significant reduction in staining intensity with MCA44 following treatment with phosphatidylinositol-specific phospholipase C, many guinea-pig DAF molecules expressed in these tissues may be of the transmembrane form. Images Figure 1 Figure 2 Figure 3 PMID:9824490

  12. Distribution of cardiovascular disease risk factors by socioeconomic status among Canadian adults

    PubMed Central

    Choinière, R; Lafontaine, P; Edwards, A C

    2000-01-01

    BACKGROUND: This study was designed to describe the distribution of risk factors for cardiovascular disease by socioeconomic status in adult men and women across Canada using the Canadian Heart Health Surveys Database. METHODS: The data were derived from provincial cross-sectional surveys done between 1986 and 1992. Data were obtained through a home interview and a clinic visit using a probability sample of 29,855 men and women aged 18-74 years of whom 23,129 (77%) agreed to participate. The following risk factors for cardiovascular disease were considered: elevated total plasma cholesterol (greater than 5.2 mmol/L), regular current cigarette smoking (one or more daily), elevated diastolic or systolic blood pressure (140/90 mm Hg), overweight (body mass index and lack of leisure-time physical activity [less than once a week in the last month]). Education and income adequacy were used as measures of socioeconomic status and mother tongue as a measure of cultural affiliation. RESULTS: For most of the risk factors examined, the prevalence of the risk factors was inversely related to socioeconomic status, but the relationship was stronger and more consistent for education than for income. The inverse relationship between socioeconomic status and the prevalence of the risk factors was particularly strong for smoking and overweight, where a gradient was observed: 46% (standard error [SE] 1.4) of men and 42% (SE 4.3) of women who had not completed secondary school were regular smokers, but only 12% (SE 1.0) of men and 13% (SE 0.9) of women with a university degree were regular smokers. Thirty-nine percent (SE 1.4) of men and 19% (SE 3.8) of women who had not completed secondary school were overweight, compared with 26% (SE 2.6) of male and 19% of female university graduates. The prevalence of leisure-time physical inactivity and elevated cholesterol was highest in both men and women in the lowest socioeconomic category, particularly by level of education. INTERPRETATION

  13. Factors driving changes in freshwater mussel (Bivalvia, Unionida) diversity and distribution in Peninsular Malaysia.

    PubMed

    Zieritz, Alexandra; Lopes-Lima, Manuel; Bogan, Arthur E; Sousa, Ronaldo; Walton, Samuel; Rahim, Khairul Adha A; Wilson, John-James; Ng, Pei-Yin; Froufe, Elsa; McGowan, Suzanne

    2016-11-15

    Freshwater mussels (Bivalvia, Unionida) fulfil important ecosystem functions and are one of the most threatened freshwater taxa globally. Knowledge of freshwater mussel diversity, distribution and ecology in Peninsular Malaysia is extremely poor, and the conservation status of half of the species presumed to occur in the region has yet to be assessed. We conducted the first comprehensive assessment of Peninsular Malaysia's freshwater mussels based on species presence/absence and environmental data collected from 155 sites spanning all major river catchments and diverse habitat types. Through an integrative morphological-molecular approach we recognised nine native and one widespread non-native species, i.e. Sinanodonta woodiana. Two species, i.e. Pilsbryoconcha compressa and Pseudodon cambodjensis, had not been previously recorded from Malaysia, which is likely a result of morphological misidentifications of historical records. Due to their restriction to single river catchments and declining distributions, Hyriopsis bialata, possibly endemic to Peninsular Malaysia, Ensidens ingallsianus, possibly already extinct in the peninsula, and Rectidens sumatrensis, particularly require conservation attention. Equally, the Pahang, the Perak and the north-western river catchments are of particular conservation value due to the presence of a globally unique freshwater mussel fauna. Statistical relationships of 15 water quality parameters and mussel presence/absence identified acidification and nutrient pollution (eutrophication) as the most important anthropogenic factors threatening freshwater mussel diversity in Peninsular Malaysia. These factors can be linked to atmospheric pollution, deforestation, oil-palm plantations and a lack of functioning waste water treatment, and could be mitigated by establishing riparian buffers and improving waste water treatment for rivers running through agricultural and residential land. PMID:27473771

  14. Factors Affecting the Spatial Distribution of Oviposition Sites for Tandem Black Saddlebags Dragonflies (Odonata: Libellulidae)

    PubMed Central

    Thornton, Jessica L.; Switzer, Paul V.

    2015-01-01

    Oviposition site location may be affected by (1) factors influencing the costs and benefits to the offspring (e.g., resource availability, competition, predation risk) and (2) factors influencing the costs and benefits to the female (e.g., predation risk or mate harassment). In cases in which both the male and female are involved in locating a site, costs and benefits may differ for each parent and the resulting oviposition site location may represent the outcome of selection pressures on one or both of them. We studied oviposition behavior in the black saddlebags dragonfly (Tramea lacerata Hagen), a species in which the male and female typically remain together (i.e., in tandem) while traveling among potential oviposition locations. Oviposition sites tended to be away from pond shoreline at the outer edge of the vegetation on the water’s surface. We found that tandems distributed their oviposition locations widely around the pond, and interactions with other dragonflies (typically other T. lacerata, either territorial males or tandems) led to a larger distance between consecutive oviposition locations. Interestingly, for 10% of the tandems, the female became separated from the male and oviposited solitarily multiple times. These solitary females spent significantly less time and traveled significantly smaller distances between successive oviposition sites than when in tandem. Our results indicate that while some aspects of oviposition behavior and site selection may be consistent between the male and female (e.g., the characteristics that make a site suitable), other aspects, such as the distribution of sites, may be a result of a differing benefits and costs for the two sexes, perhaps as a consequence of potential sperm competition.

  15. Factors Affecting Distribution of Estrogenicity in the Influents, Effluents, and Biosolids of Canadian Wastewater Treatment Plants.

    PubMed

    Shieh, Ben H H; Louie, Alvin; Law, Francis C P

    2016-05-01

    Canadian wastewater treatment plants (WWTPs) release significant amounts of estrogenic chemicals to nearby surface waters. Environmental estrogens have been implicated as the causative agents of many developmental and reproductive problems in animals, including fish. The goals of this study were to assess the estrogenic activity in the influents, effluents, and biosolids of thirteen Canadian WWTPs using the yeast estrogen screen (YES) bioassay and to investigate whether factors, such as wastewater treatment method, sample storage, extraction efficiency, population, and summer/winter temperature had any effects on the distribution of estrogenicity in the WWTPs. Results of the study showed that estrogenicity from the influent to the effluent decreased in seven WWTPs, increased in two WWTPs, and did not change in four WWTPs during the winter. Estrogenic concentrations generally decreased in the order of biosolids > influents > effluents and ranged from 1.57 to 24.6, 1.25E-02 to 3.84E-01, and 9.46E-03 to 3.90E-01 ng estradiol equivalents/g or ml, respectively. The estrogenicity in the final effluents, but not those in the influents and biosolids, was significantly higher in the summer than the winter. Among the WWTP treatment methods, advanced, biological nutrient removal appeared to be the most effective method to remove estrogenic chemicals from wastewaters in Canada. Our studies help to identify factors or mechanisms that affect the distribution of estrogenicity in WWTPs, providing a better understanding on the discharges of estrogenic chemicals from WWTPs. PMID:26433808

  16. Soil organic carbon in the Sanjiang Plain of China: storage, distribution and controlling factors

    NASA Astrophysics Data System (ADS)

    Mao, D. H.; Wang, Z. M.; Li, L.; Miao, Z. H.; Ma, W. H.; Song, C. C.; Ren, C. Y.; Jia, M. M.

    2015-03-01

    The accurate estimation of soil organic carbon (SOC) storage and determination of its pattern-controlling factors is critical to understanding the ecosystem carbon cycle and ensuring ecological security. The Sanjiang Plain, an important grain production base in China, is typical of ecosystems, yet its SOC storage and pattern has not been fully investigated because of insufficient soil investigation. In this study, 419 soil samples obtained in 2012 for each of the three soil depth ranges 0-30, 30-60, and 60-100 cm and a geostatistical method are used to estimate the total SOC storage and density (SOCD) of this region. The results give rise to 2.32 Pg C for the SOC storage and 21.20 kg m-2 for SOCD, which is higher than the mean value for the whole country. The SOCD shows notable changes in lateral and vertical distribution. In addition, vegetation, climate, and soil texture, as well as agricultural activities, are demonstrated to have remarkable impacts on the variation in SOCD of this region. Soil texture has stronger impacts on the distribution of SOCD than climate in the Sanjiang Plain. Specifically, clay content can explain the largest proportion of the SOC variations (21.2% in the top 30 cm) and is the most dominant environmental controlling factor. Additionally, the effects of both climate and soil texture on SOCD show a weakening with increasing soil layer depth. This study indicates that reducing the loss of SOC requires effective conservation and restoration efforts of wetlands and forestlands, as well as sensible fertilization. The results from this study provide the most up-to-date knowledge on the storage and pattern of SOC in the Sanjiang Plain and have important implications for the determination of ecosystem carbon budgets and understanding ecosystem services.

  17. Factors related to plaque distribution in a group of Canadian preschool children.

    PubMed

    Koroluk, L D; Hoover, J N; Komiyama, K

    1994-09-01

    The purpose of this study was to identify factors that were related to plaque distribution in a group of preschool children. 153 children aged 3-5 years from seven randomly-selected preschool programmes in Saskatoon, Canada, were examined for plaque (Silness & Loe, 1964) and for dental caries (WHO, 1987). The subjects were divided into three groups according to age: 3, 4 and 5 years old. Plaque was assessed on the buccal and lingual surfaces of all teeth. The examinations were conducted in the morning or afternoon. No prior oral hygiene instructions were given to the children or parents. Teachers, however, were informed when the examinations would take place. The mean total plaque score was 0.51. There was no significant difference between the plaque scores for the different age groups. Total plaque score was significantly related to dft and dfs scores (P < 0.05). The mean dft was 0.68 and mean dfs was 1.18, and 80.4% of the subjects were caries-free and had no restored teeth or surfaces. There was significantly more plaque on posterior teeth than on anterior teeth (P < 0.0001), and on buccal surfaces than on lingual surfaces (P < 0.001) in both mandibular and maxillary arches. Significant differences in plaque distribution were also found between subjects examined in the morning or the afternoon. PMID:7811671

  18. Factors influencing distribution ofDiabrotica spp. in blossoms of cultivatedCucurbita spp.

    PubMed

    Andersen, J F; Metcalf, R L

    1987-04-01

    Cultivars representing three species ofCucurbita were examined for blossom preference byDiabrotica spp.C. maxima cultivars were found to be preferred byD. undecimpunctata howardi over those ofC. pepo andC. moschata.D. virgifera virgifera preferredC. maxima and the "Connecticut Field" cultivar ofC. pepo.C. moschata and other cultivars ofC. pepo were not preferred. Cultivars were examined for differences in floral volatile release, blossom cucurbitacin content, and pollen content of male blossoms.C. maxima male blossoms released a larger quantity of volatiles thanC. pepo orC. moschata. Also, onlyC. maxima male blossoms contained cucurbitacins. Cultivars ofC. moschata contained the largest quantities of pollen, but all three species contained relatively large quantities. The data indicate a correspondence ofD. u. howardi distribution in the field with high volatile release rates and high cucurbitacin levels that are found inC. maxima blossoms.D. v. virgifera distribution appears to be somewhat independent of these factors since this species was abundant in blossoms of aC. pepo cultivar as well as cultivars ofC. maxima. PMID:24302038

  19. Aroma types of flue-cured tobacco in China: spatial distribution and association with climatic factors

    NASA Astrophysics Data System (ADS)

    Yang, Chao; Wu, Wei; Wu, Shu-Cheng; Liu, Hong-Bin; Peng, Qing

    2014-02-01

    Aroma types of flue-cured tobacco (FCT) are classified into light, medium, and heavy in China. However, the spatial distribution of FCT aroma types and the relationships among aroma types, chemical parameters, and climatic variables were still unknown at national scale. In the current study, multi-year averaged chemical parameters (total sugars, reducing sugars, nicotine, total nitrogen, chloride, and K2O) of FCT samples with grade of C3F and climatic variables (mean, minimum and maximum temperatures, rainfall, relative humidity, and sunshine hours) during the growth periods were collected from main planting areas across China. Significant relationships were found between chemical parameters and climatic variables ( p < 0.05). A spatial distribution map of FCT aroma types were produced using support vector machine algorithms and chemical parameters. Significant differences in chemical parameters and climatic variables were observed among the three aroma types based on one-way analysis of variance ( p < 0.05). Areas with light aroma type had significantly lower values of mean, maximum, and minimum temperatures than regions with medium and heavy aroma types ( p < 0.05). Areas with heavy aroma type had significantly lower values of rainfall and relative humidity and higher values of sunshine hours than regions with light and medium aroma types ( p < 0.05). The output produced by classification and regression trees showed that sunshine hours, rainfall, and maximum temperature were the most important factors affecting FCT aroma types at national scale.

  20. Abiotic factors affecting summer distribution and movement of male paddlefish, Polyodon spathula, in a prairie reservoir

    USGS Publications Warehouse

    Paukert, C.P.; Fisher, W.L.

    2000-01-01

    Six male paddlefish, Polyodon spathula, were implanted with ultrasonic temperature-sensing transmitters and tracked during June through August 1997 to quantify effects of physicochemical conditions on their distribution and movement in Keystone Reservoir, Oklahoma. Paddlefish moved about twice as much during night than day. Movement rate of paddlefish was related to reservoir water level, inflow, and discharge from the reservoir at night; however, none of these variables was significant during the day. Location in the reservoir (distance from the dam) was negatively related to water level and positively related to inflow during day and night periods. Location in the reservoir was negatively related to discharge during the day. Paddlefish avoided the highest available water temperatures, but did not always avoid low dissolved oxygen concentrations. Paddlefish avoided the Cimarron River arm of the reservoir in summer, possibly because of high salinity. Our study demonstrates that distribution of paddlefish during summer and movement in Keystone Reservoir was influenced by physicochemical and hydrologic conditions in the system. However, biotic factors (e.g., food availability) not measured in this study may have been influenced by abiotic conditions in the reservoir.

  1. Habitat factors influencing distributions of Anaplasma phagocytophilum and Ehrlichia chaffeensis in the Mississippi Alluvial Valley.

    PubMed

    Manangan, J S; Schweitzer, S H; Nibbelink, N; Yabsley, M J; Gibbs, S E J; Wimberly, M C

    2007-01-01

    Human monocytotropic ehrlichiosis (HME), caused by the bacterium Ehrlichia chaffeensis, and human granulocytic anaplasmosis (HGA), caused by the bacterium Anaplasma phagocytophilum, are two emerging tick-borne zoonoses of concern. Factors influencing geographic distributions of these pathogens are not fully understood, especially at varying spatial extents (regional versus landscape) and resolutions (counties versus smaller land units). We used logistic regression to compare influences of physical environment, land cover composition, and landscape heterogeneity on distributions of A. phagocytophilum and E. chaffeensis at multiple spatial extents. Pathogen presence or absence was determined from white-tailed deer (Odocoileus virginianus) serum samples collected from 1981 to 2005. Ecological predictor variables were derived from spatial datasets that represented deer density, elevation, land cover, normalized difference vegetation index (NDVI), hydrology, and soil moisture. We used three strategies (a priori, exploratory, and spatial extent) to develop models. Best fitting models were applied within a geographic information system to create predictive probability surfaces for each bacterium. Ecological predictor variables generally resulted in better fitting models for E. chaffeensis than A. phagocytophilum (90.5% and 68% sensitivity, respectively), possibly as a result of differences in the natural histories of tick vectors. Although alternative model development strategies produced different models, in all cases bacteria presence or absence was affected by a combination of soil moisture or flooding variables (thought to affect primarily tick vectors) and forest cover or NDVI variables (thought to affect primarily mammalian hosts). This research demonstrates the potential for modeling the distributions of microscopic tick-borne pathogens using coarse regional datasets and emphasizes the importance of forest cover and flooding as environmental constraints, as well as

  2. Ecological factors related to the widespread distribution of sylvatic Rhodnius ecuadoriensis populations in southern Ecuador

    PubMed Central

    2012-01-01

    Background Chagas disease transmission risk is a function of the presence of triatomines in domestic habitats. Rhodnius ecuadoriensis is one of the main vectors implicated in transmission of Trypanosoma cruzi in Ecuador. This triatomine species is present in domestic, peridomestic and sylvatic habitats in the country. To determine the distribution of sylvatic populations of R. ecuadoriensis and the factors related to this distribution, triatomine searches were conducted between 2005 and 2009 in southern Ecuador. Methods Manual triatomine searches were conducted by skilled bug collectors in 23 communities. Sylvatic searched sites were selected by a) directed sampling, where microhabitats were selected by the searchers and b) random sampling, where sampling points where randomly generated. Domiciliary triatomine searches were conducted using the one man-hour method. Natural trypanosome infection was determined by microscopic examination and PCR. Generalized linear models were used to test the effect of environmental factors on the presence of sylvatic triatomines. Results In total, 1,923 sylvatic individuals were collected representing a sampling effort of 751 man-hours. Collected sylvatic triatomines were associated with mammal and bird nests. The 1,219 sampled nests presented an infestation index of 11.9%, a crowding of 13 bugs per infested nest, and a colonization of 80% of the nests. Triatomine abundance was significantly higher in squirrel (Sciurus stramineus) nests located above five meters from ground level and close to the houses. In addition, 8.5% of the 820 examined houses in the same localities were infested with triatomines. There was a significant correlation between R. ecuadoriensis infestation rates found in sylvatic and synanthropic environments within communities (p = 0.012). Parasitological analysis revealed that 64.7% and 15.7% of the sylvatic bugs examined (n = 300) were infected with Trypanosoma cruzi and T. rangeli respectively, and 8% of the

  3. Edaphic factors affecting the vertical distribution of radionuclides in the different soil types of Belgrade, Serbia.

    PubMed

    Dragović, Snežana; Gajić, Boško; Dragović, Ranko; Janković-Mandić, Ljiljana; Slavković-Beškoski, Latinka; Mihailović, Nevena; Momčilović, Milan; Ćujić, Mirjana

    2012-01-01

    The specific activities of natural radionuclides ((40)K, (226)Ra and (232)Th) and Chernobyl-derived (137)Cs were measured in soil profiles representing typical soil types of Belgrade (Serbia): chernozems, fluvisols, humic gleysols, eutric cambisols, vertisols and gleyic fluvisols. The influence of soil properties and content of stable elements on radionuclide distribution down the soil profiles (at 5 cm intervals up to 50 cm depth) was analysed. Correlation analysis identified associations of (40)K, (226)Ra and (137)Cs with fine-grained soil fractions. Significant positive correlations were found between (137)Cs specific activity and both organic matter content and cation exchange capacity. Saturated hydraulic conductivity and specific electrical conductivity were also positively correlated with the specific activity of (137)Cs. The strong positive correlations between (226)Ra and (232)Th specific activities and Fe and Mn indicate an association with oxides of these elements in soil. The correlations observed between (40)K and Cr, Ni, Pb and Zn and also between (137)Cs and Cd, Cr, Pb and Zn could be attributed to their common affinity for clay minerals. These results provide insight into the main factors that affect radionuclide migration in the soil, which contributes to knowledge about radionuclide behaviour in the environment and factors governing their mobility within terrestrial ecosystems. PMID:22072061

  4. Scale-dependent factors affecting North American river otter distribution in the midwest

    USGS Publications Warehouse

    Jeffress, Mackenzie R.; Paukert, C.P.; Whittier, Joanna B.; Sandercock, B.K.; Gipson, P.S.

    2011-01-01

    The North American river otter (Lontra canadensis) is recovering from near extirpation throughout much of its range. Although reintroductions, trapping regulations and habitat improvements have led to the reestablishment of river otters in the Midwest, little is known about how their distribution is influenced by local- and landscape-scale habitat. We conducted river otter sign surveys from Jan. to Apr. in 2008 and 2009 in eastern Kansas to assess how local- and landscape-scale habitat factors affect river otter occupancy. We surveyed three to nine 400-m stretches of stream and reservoir shorelines for 110 sites and measured local-scale variables (e.g., stream order, land cover types) within a 100 m buffer of the survey site and landscape-scale variables (e.g., road density, land cover types) for Hydrological Unit Code 14 watersheds. We then used occupancy models that account for the probability of detection to estimate occupancy as a function of these covariates using Program PRESENCE. The best-fitting model indicated river otter occupancy increased with the proportion of woodland cover and decreased with the proportion of cropland and grassland cover at the local scale. Occupancy also increased with decreased shoreline diversity, waterbody density and stream density at the landscape scale. Occupancy was not affected by land cover or human disturbance at the landscape scale. Understanding the factors and scale important to river otter occurrence will be useful in identifying areas for management and continued restoration. ?? 2011, American Midland Naturalist.

  5. Ecological Distribution of Indicator Species and Effective Edaphical Factors on the Northern Iran Lowland Forests

    NASA Astrophysics Data System (ADS)

    Kooch, Y.; Bahmanyar, H. Jalilvand M. A.; Pormajidian, M. R.

    The objectives of this research were to identify the ecological species groups and study the relationship between topographic and edaphic factors with plant species to determine the main factors affecting the separation of vegetation types in Khanikan lowland forests of Mazandaran province (North of Iran). Vegetation was sampled with randomized-systematic method. Vegetation data including density and cover percentage were estimated quantitatively within each quadrate and using the two-way indicator species analysis (TWINSPAN). Vegetation was classified into different groups. The topographic conditions were recorded in quadrate locations. Soil samples were taken from organic horizon (litter layer) and mineral layers (0-10, 10-20 and 20-30 cm). Soil acidity, bulk density, saturation moisture, electrical conductivity, organic carbon, total nitrogen, cation exchangeable capacity, available phosphorous, soil texture, lime, biomass of earthworms, litter carbon and litter nitrogen were measured. Multivariate techniques were used to analyze the collected data. The results indicated that the vegetation distribution patters were mainly related to soil characteristics such as pH, bulk density, texture, phosphorous, organic carbon, nitrogen and CEC. Totally, considering the habitat conditions and ecological needs, each plant species has a significant relation with soil properties.

  6. Use of detrended correspondence analysis to evaluate factors controlling spatial distribution of benthic insects

    USGS Publications Warehouse

    Leland, H.V.; Carter, J.L.; Fend, S.V.

    1986-01-01

    Detrended correspondence analysis (DCA) was evaluated for its effectiveness in displaying factors controlling the spatial distribution of benthic insects in an oligotrophic stream where an experimental gradient (copper) that selectively affects population abundances was imposed. DCA proved to be highly sensitive to differences among samples and consistently provided ecologically meaningful species ordinations. Seasonality of taxa was the major gradient displayed by DCA prior to copper exposure when data for all sampling dates were included. Sensitivity of taxa to copper was a more important factor affecting community structure than was seasonality during periods of continuous exposure to copper (2.5 to 15 ??g l-1 CuT; approximately 12 to 75 ng l-1 Cu2+. When pre-dose data for each sampling date were ordinated independently, substratum composition and biological interactions were the major gradients displayed in species ordinations. During periods of exposure, sensitivity of taxa to copper was the primary gradient. This gradient also reflected a generally greater sensitivity to copper of herbivorous than of detritivorous or predatory benthic insects. DCA revealed the persistence, eleven months after dosing ceased, of differences in community structure between the control and high treatment (5 and 10 ??g l-1 CuT) sections. Differences between sections were not evident on this sampling date from total biomass or total density (numerical) estimates. ?? 1986 Dr W. Junk Publishers.

  7. Size distribution of polycyclic aromatic hydrocarbon particulate emission factors from agricultural burning

    NASA Astrophysics Data System (ADS)

    Keshtkar, Haleh; Ashbaugh, Lowell L.

    Burning of agricultural waste residue is a common method of disposal when preparing land following crop harvest. This practice introduces volatile organic compounds, including polycyclic aromatic hydrocarbons (PAHs), into the atmosphere. This study examines the particle size distribution in the smoke emissions of two common agricultural waste residues (biofuels) in California, almond prunings and rice straw. The residues were burned in a combustion chamber designed specifically for this purpose, and the smoke emissions were collected on 10-stage MOUDI impactors for analysis of PAH and total particle mass. The results, in units of emission factors, show that combustion temperature is an important factor in determining the smoke particle PAH composition. Total PAH emissions from rice straw burns were 18.6 mg kg -1 of fuel, while the emissions from almond prunings were lower at 8.03 mg kg -1. The less volatile five- and six-ring PAH was predominately on smaller particles where it condensed in the early stages of combustion while the more volatile three- and four-ring PAH formed on larger particles as the smoke cooled.

  8. Distribution and dynamics of risk factors associated with highly pathogenic avian influenza H5N1

    PubMed Central

    Zhang, L.; Guo, Z. W.; Bridge, E. S.; Li, Y. M.; Xiao, X. M.

    2016-01-01

    SUMMARY Within China’s Poyang Lake region, close interactions between wild migratory birds and domestic poultry are common and provide an opportunity for the transmission and subsequent outbreaks of highly pathogenic avian influenza (HPAI) virus. We overlaid a series of ecological factors associated with HPAI to map the risk of HPAI in relation to natural and anthropogenic variables, and we identified two hotspots for potential HPAI outbreaks in the Poyang Lake region as well as three corridors connecting the two hotspot areas. In hotspot I, there is potential for migratory birds to bring new avian influenza (AI) strains that can reassort with existing strains to form new AI viruses. Hotspot II features high-density poultry production where outbreaks of endemic AI viruses are likely. The three communication corridors that link the two hotspots further promote HPAI H5N1 transmission and outbreaks and lead to the persistence of AI viruses in the Poyang Lake region. We speculate that the region’s unevenly distributed poultry supply-and-demand system might be a key factor inducing HPAI H5N1 transmission and outbreaks in the Poyang Lake region. PMID:23398949

  9. [Spatial distribution characteristics of China cotton fiber quality and climatic factors based on GIS].

    PubMed

    Xiong, Zong-Wei; Gu, Sheng-Hao; Mao, Li-Li; Wang, Xue-Jiao; Zhang, Li-Zhen; Zhou, Zhi-Guo

    2012-12-01

    By using geographical information system (GIS), the cotton fiber quality data from 2005 to 2011 and the daily meteorological data from 1981 to 2010 at 82 sites (counties and cities) in China major cotton production regions were collected and treated with spatial interpolation. The spatial information system of cotton fiber quality in China major cotton production regions was established based on GIS, and the spatial distribution characteristics of the cotton fiber quality and their relationships with the local climatic factors were analyzed. In the northwest region (especially Xinjiang) of China, due to the abundant sunlight, low precipitation, and low relative humidity, the cotton fiber length, micronaire, and grade ranked the first. In the Yangtze River region and Yellow River region, the specific strength of cotton fiber was higher, and in the Yangtze River region, the cotton fiber length and specific strength were higher, while the micronaire and grade were lower than those in the Yellow River region. The cotton fiber quality was closely related to the climate factors such as temperature, sunlight, rainfall, and humidity. PMID:23479881

  10. Prevalence, Distribution, and Risk Factor Correlates of High Thoracic Periaortic Fat in the Framingham Heart Study

    PubMed Central

    Britton, Kathryn A.; Pedley, Alison; Massaro, Joseph M.; Corsini, Erin M.; Murabito, Joanne M.; Hoffmann, Udo; Fox, Caroline S.

    2012-01-01

    Background Thoracic periaortic adipose tissue (TAT) is associated with atherosclerosis and cardiovascular disease (CVD) risk factors and may play a role in obesity‐mediated vascular disease. We sought to determine the prevalence, distribution, and risk factor correlates of high TAT. Methods and Results Participants from the Framingham Heart Study (n=3246, 48% women, mean age 51.1 years) underwent multidetector computed tomography; high TAT and visceral adipose tissue (VAT) were defined on the basis of sex‐specific 90th percentiles in a healthy referent sample. The prevalence of high TAT was 38.1% in women and 35.7% in men. Among individuals without high VAT, 10.1% had high TAT. After adjustment for age and VAT, both women and men with high TAT in the absence of high VAT were older and had a higher prevalence of CVD (P<0.0001) compared with those without high TAT. In addition, men in this group were more likely to be smokers (P=0.02), whereas women were more likely to have low high‐density lipoprotein cholesterol (P=0.005). Conclusions Individuals in our community‐based sample with high TAT in the absence of high VAT were characterized by an adverse cardiometabolic profile. This adipose tissue phenotype may identify a subset of individuals with distinct metabolic characteristics. PMID:23316328

  11. High Q-factor distributed bragg reflector resonators with reflectors of arbitrary thickness.

    PubMed

    Le Floch, Jean-Michel; Tobar, Michael E; Cros, Dominique; Krupka, Jerzy

    2007-12-01

    The Bragg reflection technique improves the Q-factor of a resonator by reducing conductor and dielectric losses. This is achieved by designing a low-loss inner resonant region (usually free space) surrounded by an outer anti-resonant region made of distributed Bragg reflector layers. In this paper we develop a simple non-Maxwellian model and apply it to design three distinct cylindrical Bragg resonators based on the same set of single-crystal sapphire plates and rings by changing only the dimension of the cavity that supports the structure. To accomplish this, the simple model allows an arbitrary thickness for either the horizontal or the cylindrical dielectric reflectors by relaxing the condition that they must be lambda/4 thick. The model also allows for higher-order field variations in both the resonant and the anti-resonant regions. The resonators were constructed and experimental results were compared with the simple model and the rigorous method of lines analysis. For the fundamental mode, an unloaded Q-factor of 234,000 at 9.7 GHz was obtained. This is larger than that for a whispering gallery mode resonator. The resonator also exhibited a greatly reduced spurious mode density when compared to an overmoded whispering gallery mode resonator. PMID:18276575

  12. Distribution and dynamics of risk factors associated with highly pathogenic avian influenza H5N1.

    PubMed

    Zhang, L; Guo, Z W; Bridge, E S; Li, Y M; Xiao, X M

    2013-11-01

    Within China's Poyang Lake region, close interactions between wild migratory birds and domestic poultry are common and provide an opportunity for the transmission and subsequent outbreaks of highly pathogenic avian influenza (HPAI) virus. We overlaid a series of ecological factors associated with HPAI to map the risk of HPAI in relation to natural and anthropogenic variables, and we identified two hotspots for potential HPAI outbreaks in the Poyang Lake region as well as three corridors connecting the two hotspot areas. In hotspot I, there is potential for migratory birds to bring new avian influenza (AI) strains that can reassort with existing strains to form new AI viruses. Hotspot II features high-density poultry production where outbreaks of endemic AI viruses are likely. The three communication corridors that link the two hotspots further promote HPAI H5N1 transmission and outbreaks and lead to the persistence of AI viruses in the Poyang Lake region. We speculate that the region's unevenly distributed poultry supply-and-demand system might be a key factor inducing HPAI H5N1 transmission and outbreaks in the Poyang Lake region. PMID:23398949

  13. Factors Controlling the Distribution of Archaeal Tetraethers in Terrestrial Hot Springs▿

    PubMed Central

    Pearson, Ann; Pi, Yundan; Zhao, Weidong; Li, WenJun; Li, Yiliang; Inskeep, William; Perevalova, Anna; Romanek, Christopher; Li, Shuguang; Zhang, Chuanlun L.

    2008-01-01

    Glycerol dialkyl glycerol tetraethers (GDGTs) found in hot springs reflect the abundance and community structure of Archaea in these extreme environments. The relationships between GDGTs, archaeal communities, and physical or geochemical variables are underexamined to date and when reported often result in conflicting interpretations. Here, we examined profiles of GDGTs from pure cultures of Crenarchaeota and from terrestrial geothermal springs representing a wide distribution of locations, including Yellowstone National Park (United States), the Great Basin of Nevada and California (United States), Kamchatka (Russia), Tengchong thermal field (China), and Thailand. These samples had temperatures of 36.5 to 87°C and pH values of 3.0 to 9.2. GDGT abundances also were determined for three soil samples adjacent to some of the hot springs. Principal component analysis identified four factors that accounted for most of the variance among nine individual GDGTs, temperature, and pH. Significant correlations were observed between pH and the GDGTs crenarchaeol and GDGT-4 (four cyclopentane rings, m/z 1,294); pH correlated positively with crenarchaeol and inversely with GDGT-4. Weaker correlations were observed between temperature and the four factors. Three of the four GDGTs used in the marine TEX86 paleotemperature index (GDGT-1 to -3, but not crenarchaeol isomer) were associated with a single factor. No correlation was observed for GDGT-0 (acyclic caldarchaeol): it is effectively its own variable. The biosynthetic mechanisms and exact archaeal community structures leading to these relationships remain unknown. However, the data in general show promise for the continued development of GDGT lipid-based physiochemical proxies for archaeal evolution and for paleo-ecology or paleoclimate studies. PMID:18390673

  14. Seasonal distribution of systemic lupus erythematosus activity and its correlation with climate factors.

    PubMed

    Yang, Jie; Lu, Yu-Wei; Pan, Hai-Feng; Tao, Jin-Hui; Zou, Yan-Feng; Bao, Wei; Ye, Dong-Qing

    2012-08-01

    Systemic lupus erythematosus (SLE) is a complex autoimmune disease with a variety of clinical manifestations. Although inter-individual variations exist with respect to susceptibility to develop SLE, no study has been carried out to determine the role of different climate conditions in predisposing the susceptible individuals to SLE. The objective of this study was to investigate the role of different seasons and climate factors on SLE activity. From 2000 to 2009, the seasonal distribution of 2,802 active SLE patients recruited from Anhui Provincial Hospital and the First Affiliated Hospital of Anhui Medical University was analyzed retrospectively. The climate data were provided by the Institute of Geographical Sciences and Resources, Chinese Academy of Sciences. The correlation between climate factors and SLE activity was also analyzed. The proportion of active SLE patients in winter, spring, summer, and autumn was 10.06, 10.31, 9.74, and 8.66‰, respectively. In autumn, the proportion was much lower than that in winter and spring (P < 0.05). The proportion among winter, spring, and summer had no statistical difference (P > 0.05). The number of active SLE patients had no correlation with air temperature (r = 0.483, P > 0.05), relative humidity (r = -0.294, P > 0.05), and sunshine percentage (r = 0.503, P > 0.05), but it had positive correlation with amount of precipitation (r = 0.601, P < 0.05), wind velocity (r = 0.713, P < 0.01), and sunshine duration (r = 0.769, P < 0.01) and negative correlation with barometric pressure (r = -0.664, P < 0.05). The disease activity of patients with SLE is affected by seasons and climate factors. PMID:21667078

  15. Geohelminths distribution as affected by soil properties, physicochemical factors and climate in Sharkyia governorate Egypt.

    PubMed

    Etewa, Samia E; Abdel-Rahman, Sara A; Abd El-Aal, Naglaa F; Fathy, Ghada M; El-Shafey, Mahmoud A; Ewis, A M G

    2016-06-01

    Soil-transmitted helminths are mainly a group of parasitic nematodes causing human infection through contact with parasite eggs or larvae; they survive in the warm and moist soil of the tropical and subtropical countries. This study was carried out in Sharkyia governorate from October, 2011 to October, 2013, to correlate between the prevalence and distribution of these parasites in the soil and the physicochemical factors affecting the examined samples of the soil. One hundred and twenty samples of different types of soil (clay, silt, sand) from different localities were collected and examined. Diagnosis of geohelminths was confirmed by the recovery of their eggs and larvae with other protozoa by different parasitological methods. The modified baermann method was found to be more efficient in detection of geohelminths larvae than charcoal culture method. Among the examined sites geohelminths were much more numerous in the soil of rural areas especially in the spring and summer seasons, while the contamination of canal banks by geohelminths was the worst (80 %). An insignificant correlation was reported between the soil texture and the number of positive samples in the examined areas while the relationship was directly proportional among (moisture, PH, organic). It appeared that the most common geohelminthic stage was Toxocara spp. eggs besides other types of protozoa especially Balantidium coli cysts. This suggests that factors other than soil texture are important in the prevalence of geohelminths in the soil e.g. temperature, moisture, PH and organic matter. So, to change some of these factors in a trial to control geoparasites transmission but with keeping the environment should be tried. These results also open the way to further studies to highlight the mutual affection between inhabitants of these sites and the prevalence of these geoparasites. PMID:27413327

  16. Factors controlling the distribution of archaeal tetraethers in terrestrial hot springs.

    PubMed

    Pearson, Ann; Pi, Yundan; Zhao, Weidong; Li, WenJun; Li, Yiliang; Inskeep, William; Perevalova, Anna; Romanek, Christopher; Li, Shuguang; Zhang, Chuanlun L

    2008-06-01

    Glycerol dialkyl glycerol tetraethers (GDGTs) found in hot springs reflect the abundance and community structure of Archaea in these extreme environments. The relationships between GDGTs, archaeal communities, and physical or geochemical variables are underexamined to date and when reported often result in conflicting interpretations. Here, we examined profiles of GDGTs from pure cultures of Crenarchaeota and from terrestrial geothermal springs representing a wide distribution of locations, including Yellowstone National Park (United States), the Great Basin of Nevada and California (United States), Kamchatka (Russia), Tengchong thermal field (China), and Thailand. These samples had temperatures of 36.5 to 87 degrees C and pH values of 3.0 to 9.2. GDGT abundances also were determined for three soil samples adjacent to some of the hot springs. Principal component analysis identified four factors that accounted for most of the variance among nine individual GDGTs, temperature, and pH. Significant correlations were observed between pH and the GDGTs crenarchaeol and GDGT-4 (four cyclopentane rings, m/z 1,294); pH correlated positively with crenarchaeol and inversely with GDGT-4. Weaker correlations were observed between temperature and the four factors. Three of the four GDGTs used in the marine TEX(86) paleotemperature index (GDGT-1 to -3, but not crenarchaeol isomer) were associated with a single factor. No correlation was observed for GDGT-0 (acyclic caldarchaeol): it is effectively its own variable. The biosynthetic mechanisms and exact archaeal community structures leading to these relationships remain unknown. However, the data in general show promise for the continued development of GDGT lipid-based physiochemical proxies for archaeal evolution and for paleo-ecology or paleoclimate studies. PMID:18390673

  17. Data analysis as a source of variability of the HLA-peptide multimer assay: from manual gating to automated recognition of cell clusters

    PubMed Central

    Gouttefangeas, Cécile; Chan, Cliburn; Attig, Sebastian; Køllgaard, Tania T.; Rammensee, Hans-Georg; Stevanović, Stefan; Wernet, Dorothee; Straten, Per thor; Welters, Marij J.P.; Ottensmeier, Christian; van der Burg, Sjoerd H.; Britten, Cedrik M.

    2015-01-01

    Multiparameter flow cytometry is an indispensable method for assessing antigen-specific T cells in basic research and cancer immunotherapy. Proficiency panels have shown that cell sample processing, test protocols and data analysis may all contribute to the variability of the results obtained by laboratories performing ex vivo T-cell immune monitoring. In particular, analysis currently relies on a manual, step-by-step strategy employing serial gating decisions based on visual inspection of one- or two-dimensional plots. It is therefore operator dependent and subjective. In the context of continuing efforts to support inter-laboratory T-cell assay harmonization, the Immunoguiding Program organized its third proficiency panel dedicated to the detection of antigen-specific CD8+ T cells by HLA-peptide multimer staining. We first assessed the contribution of manual data analysis to the variability of reported T-cell frequencies within a group of laboratories staining and analyzing the same cell samples with their own reagents and protocols. The results show that data analysis is a source of variation in the multimer assay outcome. To evaluate if an automated analysis approach can reduce variability of proficiency panel data, we used a hierarchical statistical mixture model to identify cell clusters. Challenges for automated analysis were the need to process non-standardized data sets from multiple centers, and the fact that the antigen-specific cell frequencies were very low in most samples. We show that this automated method can circumvent difficulties inherent to manual gating strategies and is broadly applicable for experiments performed with heterogeneous protocols and reagents. PMID:25854580

  18. Data analysis as a source of variability of the HLA-peptide multimer assay: from manual gating to automated recognition of cell clusters.

    PubMed

    Gouttefangeas, Cécile; Chan, Cliburn; Attig, Sebastian; Køllgaard, Tania T; Rammensee, Hans-Georg; Stevanović, Stefan; Wernet, Dorothee; thor Straten, Per; Welters, Marij J P; Ottensmeier, Christian; van der Burg, Sjoerd H; Britten, Cedrik M

    2015-05-01

    Multiparameter flow cytometry is an indispensable method for assessing antigen-specific T cells in basic research and cancer immunotherapy. Proficiency panels have shown that cell sample processing, test protocols and data analysis may all contribute to the variability of the results obtained by laboratories performing ex vivo T cell immune monitoring. In particular, analysis currently relies on a manual, step-by-step strategy employing serial gating decisions based on visual inspection of one- or two-dimensional plots. It is therefore operator dependent and subjective. In the context of continuing efforts to support inter-laboratory T cell assay harmonization, the CIMT Immunoguiding Program organized its third proficiency panel dedicated to the detection of antigen-specific CD8(+) T cells by HLA-peptide multimer staining. We first assessed the contribution of manual data analysis to the variability of reported T cell frequencies within a group of laboratories staining and analyzing the same cell samples with their own reagents and protocols. The results show that data analysis is a source of variation in the multimer assay outcome. To evaluate whether an automated analysis approach can reduce variability of proficiency panel data, we used a hierarchical statistical mixture model to identify cell clusters. Challenges for automated analysis were the need to process non-standardized data sets from multiple centers, and the fact that the antigen-specific cell frequencies were very low in most samples. We show that this automated method can circumvent difficulties inherent to manual gating strategies and is broadly applicable for experiments performed with heterogeneous protocols and reagents. PMID:25854580

  19. Factors influencing aerodynamic particle size distribution of suspension pressurized metered dose inhalers.

    PubMed

    Sheth, Poonam; Stein, Stephen W; Myrdal, Paul B

    2015-02-01

    Pressurized metered dose inhalers (pMDIs) are frequently used for the treatment of asthma and chronic obstructive pulmonary disease. The aerodynamic particle size distribution (APSD) of the residual particles delivered from a pMDI plays a key role in determining the amount and region of drug deposition in the lung and thereby the efficacy of the inhaler. In this study, a simulation model that predicts the APSD of residual particles from suspension pMDIs was utilized to identify the primary determinants for APSD. These findings were then applied to better understand the effect of changing drug concentration and micronized drug size on experimentally observed APSDs determined through Andersen Cascade Impactor testing. The experimental formulations evaluated had micronized drug mass median aerodynamic diameters (MMAD) between 1.2 and 2.6 μm and drug concentrations ranging from 0.01 to 1% (w/w) with 8.5% (w/w) ethanol in 1,1,1,2-tetrafluoroethane (HFA-134a). It was determined that the drug concentration, micronized drug size, and initially atomized droplet distribution have a significant impact in modulating the proportion of atomized droplets that contain multiple suspended drug particles, which in turn increases the residual APSD. These factors were found to be predictive of the residual particle MMAD for experimental suspension HFA-134a formulations containing ethanol. The empirical algebraic model allows predicting the residual particle size for a variety of suspension formulations with an average error of 0.096 μm (standard deviation of 0.1 μm). PMID:25273026

  20. [Influence on the spatial distribution of fish in Taizi River basin by environmental factors at multiple scales].

    PubMed

    Ding, Sen; Zhang, Yuan; Qu, Xiao-Dong; Kong, Wei-Jing; Liu, Si-Si; Meng, Wei

    2012-07-01

    The deterioration of fish is influenced by various types of environmental factors. To develop protection plans that are more suitable, non-metric multidimensional scaling analysis (NMS) was used to investigate the influence of environmental factors at multiple scales on the spatial distribution of fish. The results of cluster analysis showed that there were three types of spatial distribution of fish, i.e. upstream timber and tributary headstream area, midstream hilly area, and downstream plain area. Results of NMS analysis indicated the significant correlations between spatial distribution of fish and environmental factors at multiple scales. Altitude, stream order and land use were three important factors influencing the fish distribution at the watershed scale. Combination of velocity and depth, habitat inhomogeneity and electrical conductivity significantly affected fish distribution at the reach scale, whereas the quality of bottom material showed significant influence at the microhabitat scale. Therefore, the effect of specific environmental factors at multiple scales should be taken into consideration in the basin fish conversation management. PMID:23002601

  1. Effect of water content on strontium retardation factor and distribution coefficient in Chinese loess.

    PubMed

    Huo, Lijuan; Qian, Tianwei; Hao, Junting; Liu, Hongfang; Zhao, Dongye

    2013-12-01

    Geological burial and landfill are often employed for disposal of nuclear wastes. Typically, radionuclides from nuclear facilities transport through the unsaturated zone before reaching the groundwater aquifer. However, transport studies are often conducted under saturated and steady-state flow conditions. This research aimed to examine the effects of unsaturated flow conditions and soil water content (θ) on Sr sorption and retardation in Chinese loess through 1D column transport experiments. Reagent SrCl2 was used as a surrogate for the radioactive isotope ((90)Sr) in the experiment because of their analogous adsorption and transportation characteristics. The spatial distribution of Sr along the column length was determined by segmenting the soil bed and analysing the Sr content in each soil segment following each column breakthrough test. The single-region (SR) and two-region (TR) models were employed to interpret the transport data of Sr as well as a tracer (Br(-)), which resulted in the dispersion coefficient (D) and retardation factor (Rd) under a given set of unsaturated flow conditions. For the tracer, the SR and TR models offered nearly the same goodness of fitting to the breakthrough curves (R(2) ≈ 0.97 for both models). For the highly sorptive Sr, however, the TR model provided better fitting (R(2), 0.80-0.96) to the Sr retention profiles than the SR model (R(2), 0.20-0.89). The Sr retention curves exhibited physical non-equilibrium characteristics, particularly at lower water content of the soil. For the unsaturated soil, D and the pore water velocity (v) displayed a weak linear correlation, which is attributed to the altering dispersivity as the water content varies. A much improved linear correlation was observed between D and v/θ. The retardation factor of Sr increased from 69.1 to 174.2 as θ decreased from 0.46 to 0.26 (cm(3) cm(-3)), while the distribution coefficient (Kd) based on Rd remained nearly unchanged at various θ levels. These

  2. Distribution of Fasciola hepatica in Swedish dairy cattle and associations with pasture management factors.

    PubMed

    Novobilský, Adam; Sollenberg, Sofia; Höglund, Johan

    2015-01-01

    The geographic distribution of Fasciola hepatica infection in relation to management routines was studied in Swedish dairy herds by testing for F. hepatica antibodies with the enzyme-linked immunosorbent assay (ELISA). In addition, all farmers were sent a questionnaire asking for information about type of production, management routines and historical record of F. hepatica at slaughter. A total of 176 farmers (41%) responded to the questionnaire. A total of 426 bulk tank milk (BTM) samples were randomly selected from the period September to October 2012 representing approximately 10% of all herds in Sweden. The overall seroprevalence was 25% (n = 107; 95% confidence interval = 21-29%) with a concentration of herds located in south-western Sweden. Among the seropositive herds, 31 (29%) had antibody levels indicating production loss. There were no significant differences in seropositivity between organic and conventional herds or due to pasture management routines. The length of grazing period, which increased the risk for heifers, was found to be the most influential factor. A discrepancy was noted between reported F. hepatica presence at meat inspection and herds that were seropositive based on BTM-ELISA results. Although the largest proportion of seropositive BTM samples (80%) came from herds where liver fluke presence had been observed at meat inspection after slaughter, seropositive BTM samples were also diagnosed in five herds (17%) with no remarks at slaughter. In conclusion, F. hepatica is a common parasite in Swedish dairy herds and the month of heifer turn-out and the grazing period length were the most influential factors observed. PMID:25826310

  3. [Temporal and Spatial Distribution Characteristics of Dissolved Organic Matter and Influencing Factors in Lake Chaohu].

    PubMed

    Ye, Lin-lin; Wu, Xiao-dong; Liu, Bo; Yan, De-zhi; Zhang, Mei-qi; Zhou, Yang

    2015-09-01

    To study the temporal and spatial distribution of dissolved organic matter (DOM) and the related influencing factors of Lake Chaohu, surface water samples were collected at seventeen sites in three different regions of the Lake from April 2013 to April 2014. The concentration of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) were then analyzed. A significance difference in DON concentration was observed among the sampling sites (P <0. 01, n = 13), which was caused by the terrestrial input from the western rivers and the bioavailability of DON. The ratio of total nitrogen to total phosphorus, total dissolved nitrogen to total dissolved phosphorus, and dissolved inorganic nitrogen to soluble reactive phosphorus (DIN/SRP) declined gradually during the phytoplankton bloom period, especially the ratio of DIN/SRP dropped to 5 ± 7 in August 2013, indicating the nitrogen was limited in lake water. Moreover, the concentration of DON was decreased and a significant negative correlation was observed between DON and Chl-a (r = - 0. 265, P < 0. 05, n = 91), suggesting that DON is bioavailable, and can be utilized by phytoplankton directly or indirectly during nitrogen limitation. No significant difference in DOC concentration was observed and water temperature was the major factor related to the variation of DOC. Chl-a and nitrate concentrations can also affect the dynamics of DOC. In addition, the ratio of DOC/DON was considerably varied, the concentration of DON contributed to the variation of DOC/DON, and DON was the major component contributed to the bioavailability of DOM. PMID:26717677

  4. What factors drive copepod community distribution in the Gulf of Gabes, Eastern Mediterranean Sea?

    PubMed

    Drira, Zaher; Bel Hassen, Malika; Ayadi, Habib; Aleya, Lotfi

    2014-02-01

    The spatial and temporal variations in copepod communities were investigated during four oceanographic cruises conducted between July 2005 and March 2007 aboard the R/V Hannibal. A close relationship was observed between the temperature, salinity, hydrographic properties and water masses characterising the Gulf of Gabes. Indeed, water thermal stratification began in May-June, and a thermocline was established at a 20-m depth, but ranged from 25 m in July to more than 30 m in September. The zooplankton community is dominated by copepods representing 69 % to 83 % of total zooplankton. Spatial and temporal variation of copepods in relation to environmental factors shows their close relationship with the hydrodynamic features of the water column. Thermal stratification in the column, established in summer, supports copepod development. In fact, copepod abundance increases gradually with rising water temperature and salinity, starting from the beginning of thermal stratification (May-June 2006) and lasting until its completion (July 2005 and September 2006). When the water column is well mixed (March 2007), copepod abundance decreased. Our finding shows that temperature and salinity seem to be the most important physical factors and thus strongly influence the taxonomic diversity and distribution of the copepod population. They are characterised by the dominance of Oithona nana, representing 75-86 % of total cyclopoid abundance. The most abundant species during the stratification period were O. nana, Acartia clausi and Stephos marsalensis in July 2005 and September 2006. However, during the mixing period, Euterpina acutifrons was more abundant, representing 21 % of the total. Unlike the copepod community, which is more abundant during the period of high stratification, phytoplankton proliferates during semi-mixed conditions. PMID:24170503

  5. Temperature-averaged and total free-free Gaunt factors for κ and Maxwellian distributions of electrons

    NASA Astrophysics Data System (ADS)

    de Avillez, Miguel A.; Breitschwerdt, Dieter

    2015-08-01

    Aims: Optically thin plasmas may deviate from thermal equilibrium and thus, electrons (and ions) are no longer described by the Maxwellian distribution. Instead they can be described by κ-distributions. The free-free spectrum and radiative losses depend on the temperature-averaged (over the electrons distribution) and total Gaunt factors, respectively. Thus, there is a need to calculate and make available these factors to be used by any software that deals with plasma emission. Methods: We recalculated the free-free Gaunt factor for a wide range of energies and frequencies using hypergeometric functions of complex arguments and the Clenshaw recurrence formula technique combined with approximations whenever the difference between the initial and final electron energies is smaller than 10-10 in units of z2Ry. We used double and quadruple precisions. The temperature-averaged and total Gaunt factors calculations make use of the Gauss-Laguerre integration with 128 nodes. Results: The temperature-averaged and total Gaunt factors depend on the κ parameter, which shows increasing deviations (with respect to the results obtained with the use of the Maxwellian distribution) with decreasing κ. Tables of these Gaunt factors are provided. Appendices are available in electronic form at http://www.aanda.org

  6. Transfer factor, lung volumes, resistance and ventilation distribution in healthy adults.

    PubMed

    Verbanck, Sylvia; Van Muylem, Alain; Schuermans, Daniel; Bautmans, Ivan; Thompson, Bruce; Vincken, Walter

    2016-01-01

    Monitoring of chronic lung disease requires reference values of lung function indices, including putative markers of small airway function, spanning a wide age range.We measured spirometry, transfer factor of the lung for carbon monoxide (TLCO), static lung volume, resistance and ventilation distribution in a healthy population, studying at least 20 subjects per sex and per decade between the ages of 20 and 80 years.With respect to the Global Lung Function Initiative reference data, our subjects had average z-scores for forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC of -0.12, 0.04 and -0.32, respectively. Reference equations were obtained which could account for a potential dependence of index variability on age and height. This was done for (but not limited to) indices that are pertinent to asthma and chronic obstructive pulmonary disease studies: forced expired volume in 6 s, forced expiratory flow, TLCO, specific airway conductance, residual volume (RV)/total lung capacity (TLC), and ventilation heterogeneity in acinar and conductive lung zones.Deterioration in acinar ventilation heterogeneity and lung clearance index with age were more marked beyond 60 years, and conductive ventilation heterogeneity showed the greatest increase in variability with age. The most clinically relevant deviation from published reference values concerned RV/TLC values, which were considerably smaller than American Thoracic Society/European Respiratory Society-endorsed reference values. PMID:26585426

  7. [Distribution Characteristics and Influencing Factors of Nitrate Pollution in Shallow Groundwater of Liujiang Basin].

    PubMed

    Wang, He; Gu, Hong-biao; Chi, Bao-ming; Li, Hai-jun; Jiang, Hai-ning

    2016-05-15

    Taking the nitrate in shallow groundwater of Liujiang basin as the research object, a total of 215 groups of shallow groundwater samples were collected during the wet period in July 2014 and the drought period in April 2015 on the basis of groundwater pollution investigation. The characteristics of spatial and temporal variability and the account of nitrate pollution were analyzed based on the model of semivariogram, the geostatistics of ArcGIS and factor analysis, respectively. The results showed that the study region in the southeast was the main nitrate-polluted area, with concentrations of up to 30-120 mg · L⁻¹, in both wet and drought periods, while the nitrate-contaminated area in drought period was about 1. 4 times higher than that in wet period. The spatial distribution of nitrate was primarily influenced by human activities and the geological conditions, and secondarily by Eh, DO, pH and landform conditions. The nitrate concentration was less than 20 mg · L⁻¹ in north. Pollution in local middle area was rather serious, due to human activities and the loss of nitrogen fertilizer in agricultural cultivation; the area to the south, which was confined by impervious boundary, was seriously contaminated, as indicated by the nitrate accumulation effects. PMID:27506022

  8. Social distribution of diabetes, hypertension and related risk factors in Barbados: a cross-sectional study

    PubMed Central

    Howitt, Christina; Hambleton, Ian R; Rose, Angela M C; Hennis, Anselm; Samuels, T Alafia; George, Kenneth S; Unwin, Nigel

    2015-01-01

    Objective To describe the distribution of diabetes, hypertension and related behavioural and biological risk factors in adults in Barbados by gender, education and occupation. Design Multistage probability sampling was used to select a representative sample of the adult population (≥25 years). Participants were interviewed using standard questionnaires, underwent anthropometric and blood pressure measurements, and provided fasting blood for glucose and cholesterol measurements. Standard WHO definitions were used. Data were weighted for sampling and non-response, and were age and sex standardised to the 2010 Barbados population. Weighted prevalence estimates were calculated, and prevalence ratios were calculated for behavioural and biological risk factors by demographic and socioeconomic group. Results Study response rate was 55.0%, with 764 women, 470 men. Prevalence of obesity was 33.8% (95% CI 30.7% to 37.1%); hypertension 40.6% (95% CI 36.5% to 44.9%); and diabetes 18.7% (95% CI 16.2% to 21.4%). Compared with women, men were less likely to be obese (prevalence ratio 0.5; 95% CI 0.4 to 0.7), or physically inactive (0.5; 0.4 to 0.6), but more likely to smoke tobacco (4.1; 2.5 to 6.7) and consume large amounts of alcohol in a single episode (4.6; 2.7 to 7.6). Both diabetes (0.83; 0.65 to 1.05) and hypertension (0.89; 0.79 to 1.02) were lower in men, but not significantly so. In women, higher educational level was related to higher fruit and vegetable intake, more physical activity, less diabetes and less hypercholesterolaemia (p 0.01–0.04). In men, higher education was related only to less smoking (p 0.04). Differences by occupation were limited to smoking in men and hypercholesterolaemia in women. Conclusions In this developing country population, sex appears to be a much stronger determinant of behavioural risk factors, as well as obesity and its related risks, than education or occupation. These findings have implications for meeting the commitments made

  9. Surface-enhanced Raman scattering enhancement factor distribution for nanoparticles of arbitrary shapes using surface integral equation method

    NASA Astrophysics Data System (ADS)

    Ying Huang, Shao; Wu, Bae-Ian; Foong, Shaohui

    2013-01-01

    Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) surface integral equation method is applied for the first time to accurately estimate the surface-enhanced Raman scattering (SERS) enhancement factor distribution for arbitrary nanoparticles and nano-aggregates. It is the first time in literature that the distributions of SERS enhancement factors of nanoparticles of a large variety are reported. It is shown that not every SERS substrate exhibits a long-tail distribution as a dimer consisting of two spheres in close proximity. Generic methods are proposed to evaluate the performance of nanoparticles on SERS substrates. A cumulative distribution is proposed to examine the contributions of hot and warm spots around the nanoparticles. It is used to identify the importance of warm spots on a SERS substrate. A parameter q is proposed to describe the likelihood of a randomly positioned molecule that can be activated. This study provides guidance and insights for the optimization of SERS substrate fabrication techniques.

  10. A Study on Voltage Rise Control Effect by Leading Power Factor Operation of PVs Considering Tap Change of Distribution Transformer

    NASA Astrophysics Data System (ADS)

    Ishimaru, Masa-Aki; Tamachi, Hideki; Komami, Shintaroh

    Voltage rise problem in distribution networks has been discussed as the foremost concern against the penetration of large amount of photovoltaics (PVs). As a solution of such problem, using voltage regulation facility such as SVC (Static Var Compensator) or Loop power flow controller are proposed. However, it might require major investments in the distribution network and that means the cost would be imposed on the nation. In this paper, the authors focus on latent ability of the present distribution network and PVs to find solution against the problem and propose a low cost solution to mitigate the voltage rise by using constant leading power factor operation of PVs. The distribution voltages are calculated in case of increasing highly penetrated PVs, where it is very important to make an aggregated model of the distribution networks including loads and PVs. The authors aggregate a lot of loads and PVs by using an aggregation method called “Y-connection”. As a result of having simulated with the aggregated realistic model of distribution networks, the authors confirmed that using a combination of leading power factor operation by Q = -0.2P and LDC of distribution transformer make it possible to maintain adequate voltage without voltage regulation facility such as SVC.

  11. Seroprevalence, distribution and risk factor for peste des petits ruminants (PPR) in Algeria.

    PubMed

    Kardjadj, Moustafa; Kouidri, Brahim; Metref, Djamil; Luka, Pam Dachung; Ben-Mahdi, Meriem Hind

    2015-11-01

    Peste des petit ruminants (PPR) is a highly contagious and infectious viral disease of small ruminants with severe socio-economic implications. The disease was first reported in the Southern part of Algeria in 2011 and by February 2012 it has reached the central part of the country. Estimating national prevalence, distribution and identification of risk factors remains a key component in understanding the epidemiology and control of the disease. The present study was carried out between January and June 2014, to include a detailed description of flock and within-flock seroprevalence and risk association between PPR seropositivity and various flock management factors in Algeria. A total of 150 flocks randomly sampled across the country were investigated and 4552 serum samples were collected from 3336 sheep and 1216 goats, respectively. C-ELISA was used to detect the presence of antibodies in small ruminant animals as an indicator of PPRV exposure. The results showed an overall true flock seroprevalence of 30.45% [95% CI 23.76-37.14] with a mean of the true within-flock prevalence as 29.87%±2.11. The mean of the true within-flock prevalence in mixed flocks (12.93%±1.85) was however found to be significantly higher than sheep flocks (5.74%±1.06). Also the mean of the true within-flock prevalence was found to be significantly higher in adult (35.36%±3.13) compared to young animals (21.83%±2.47) and in females (33.11%±2.87) compared to males (22.14%±2.31). The univariate analysis revealed that PPR overall flock seroprevalence was significantly higher (P<0.20) in large flock (50.61%) than in small flock (33.33%), in mixed flock (56.7%) than in sheep flock (35.35%) and in the flocks that had contact with other flocks (46.5%) compared to those who had not (30.6%). However the differences among studied regions and grazing system were not statistically significant. For the risk factor analysis, univariate analysis of variables followed by a multiple logistic

  12. The distributions of one invasive and two native crayfishes in relation to coarse-scale natural and anthropogenic factors

    USGS Publications Warehouse

    Westhoff, J.T.; Rabeni, C.F.; Sowa, S.P.

    2011-01-01

    1. Native crayfishes are often extirpated from portions of their range because of interactions with invasive species, anthropogenic alterations to environmental conditions or a combination of these factors. Our goal was to identify coarse-scale natural and anthropogenic factors related to the current distributions of the invasive crayfish, Orconectes hylas, and two endemic crayfishes, Orconectes peruncus andOrconectes quadruncus in the St. Francis River drainage, Missouri, U.S.A. and to provide wider insights into the potential role of anthropogenic factors in facilitating species displacement. 2. We used classification trees to model coarse-scale natural and anthropogenic environmental factors and their relation to the presence or absence of each species. Model results were then used to predict probability of presence for each species within each stream segment throughout the entire St. Francis River drainage. 3. Factors related to geology and soils were the best predictors of species distributions. A dichotomy of these factors explained much of the discrete distributions of the two native species. Agricultural-related factors were identified as the most influential anthropogenic activity related to species distributions. All associations between the invasive species and anthropogenic factors were negative which suggested the invader was not likely to establish in heavily impacted areas. Overall, our models had high correct classification rates, and we were able to reliably predict the presence of the invader in the invaded drainage. 4. Given the negative associations of the invader with anthropogenic alterations at a coarse spatial scale, we believe other mechanisms are likely to be responsible for the widespread displacement of the two native species. These findings can be used to assist in conservation activities such as creation of refugia for native species and may direct future research to identify the mechanism(s) of species displacement.

  13. Distribution of radio refractivity gradient and effective earth radius factor (k-factor) over Akure, South Western Nigeria

    NASA Astrophysics Data System (ADS)

    Adediji, A. T.; Ajewole, M. O.; Falodun, S. E.

    2011-10-01

    Refractivity gradient and k-factor variations, based on measurements of atmospheric pressure, temperature and relative humidity made in Akure North (7.15°N, 5.12°E), South Western Nigeria, is reported. The measurement was made using wireless weather stations (Integrated Sensor Suite, ISS) positioned at five different height levels beginning from the ground surface and at intervals of 50 m to a height of 200 m on a 220 m idled TV tower. The study utilised 2 years of meteorological data measured from January 2007 to December 2008 to calculate refractivity, its gradient and the effective Earth radius factor (k-factor). From the results, refractivity values were observed to be generally high during the rainy season (April-October) and the values decreased with increasing altitude. The average refractivity gradient was -52.8 N-units/km and the average value of k-factor is 1.51 for the 2 year period of this report.

  14. Factors related to occurrence and distribution of selected bacterial and protozoan pathogens in Pennsylvania streams

    USGS Publications Warehouse

    Duris, Joseph W.; Reif, Andrew G.; Donna A. Crouse; Isaacs, Natasha M.

    2013-01-01

    The occurrence and distribution of fecal indicator bacteria (FIB) and bacterial and protozoan pathogens are controlled by diverse factors. To investigate these factors in Pennsylvania streams, 217 samples were collected quarterly from a 27-station water-quality monitoring network from July 2007 through August 2009. Samples were analyzed for concentrations of Escherichia coli (EC) and enterococci (ENT) indicator bacteria, concentrations of Cryptosporidium oocysts and Giardia cysts, and the presence of four genes related to pathogenic types of EC (eaeA, stx2, stx1, rfbO157) plus three microbial source tracking (MST) gene markers that are also associated with pathogenic ENT and EC (esp, LTIIa, STII). Water samples were concurrently analyzed for basic water chemistry, physical measures of water quality, nutrients, metals, and a suite of 79 organic compounds that included hormones, pharmaceuticals, and antibiotics. For each sample location, stream discharge was measured by using standardized methods at the time of sample collection, and ancillary sample site information, such as land use and geological characteristics, was compiled. Samples exceeding recreational water quality criteria were more likely to contain all measured pathogen genes but notCryptosporidium or Giardia (oo)cysts. FIB and Giardia density and frequency of eaeA gene occurrence were significantly related to season. When discharge at a sampling location was high (>75th percentile of daily mean discharge), there were greater densities of FIB and Giardia, and the stx2, rfbO157, STII, and esp genes were found more frequently than at other discharge conditions. Giardia occurrence was likely related to nonpoint sources, which are highly influential during seasonal overland transport resulting from snowmelt and elevated precipitation in late winter and spring in Pennsylvania. When MST markers of human, swine, or bovine origin were present, samples more frequently carried the eaeA, stx2

  15. Spatial distribution and risk factors of Brucellosis in Iberian wild ungulates

    PubMed Central

    2010-01-01

    Background The role of wildlife as a brucellosis reservoir for humans and domestic livestock remains to be properly established. The aim of this work was to determine the aetiology, apparent prevalence, spatial distribution and risk factors for brucellosis transmission in several Iberian wild ungulates. Methods A multi-species indirect immunosorbent assay (iELISA) using Brucella S-LPS antigen was developed. In several regions having brucellosis in livestock, individual serum samples were taken between 1999 and 2009 from 2,579 wild bovids, 6,448 wild cervids and4,454 Eurasian wild boar (Sus scrofa), and tested to assess brucellosis apparent prevalence. Strains isolated from wild boar were characterized to identify the presence of markers shared with the strains isolated from domestic pigs. Results Mean apparent prevalence below 0.5% was identified in chamois (Rupicapra pyrenaica), Iberian wild goat (Capra pyrenaica), and red deer (Cervus elaphus). Roe deer (Capreolus capreolus), fallow deer (Dama dama), mouflon (Ovis aries) and Barbary sheep (Ammotragus lervia) tested were seronegative. Only one red deer and one Iberian wild goat resulted positive in culture, isolating B. abortus biovar 1 and B. melitensis biovar 1, respectively. Apparent prevalence in wild boar ranged from 25% to 46% in the different regions studied, with the highest figures detected in South-Central Spain. The probability of wild boar being positive in the iELISA was also affected by age, age-by-sex interaction, sampling month, and the density of outdoor domestic pigs. A total of 104 bacterial isolates were obtained from wild boar, being all identified as B. suis biovar 2. DNA polymorphisms were similar to those found in domestic pigs. Conclusions In conclusion, brucellosis in wild boar is widespread in the Iberian Peninsula, thus representing an important threat for domestic pigs. By contrast, wild ruminants were not identified as a significant brucellosis reservoir for livestock. PMID:20205703

  16. Determination of Stress Intensity Factor Distributions for "Interface" Cracks in Incompressible, Dissimilar Materials

    NASA Technical Reports Server (NTRS)

    Smith, C. W.

    1997-01-01

    The present study was undertaken in order to develop test methods and procedures for measuring the variation of the stress intensity factor through the thickness in bimaterial specimens containing cracks within and parallel to the bond line using the frozen stress photoelastic method. Since stress freezing materials are incompressible above critical temperature, and since thick plates are to be employed which tend to produce a state of plane strain near the crack tip, the interface near tip fracture equations reduce to the classic form for homogeneous materials. Moreover, zero thickness interfaces do not exist when materials are bonded together. It was decided early on that it would be important to insure a uniform straight and accurate crack tip region through the thickness of the body to reduce scatter in the SIF distribution through the thickness. It was also observed that rubberlike materials which were desired to be modeled exhibited significant tip blunting prior to crack extension and that some blunting of the tip would provide a more realistic model. It should be noted that, in normal stress freezing photoelastic work, it is considered good practice to avoid utilizing data near bond lines in photoelastic models due to the bond line stresses which inevitably develop when two parts are bonded together. Thus, the present study involves certain exploratory aspects in deviating from standard practice in stress freezing work. With the above ideas in mind, several different test methods were investigated and are described in the following sections and appendices. The geometry selected for the program was a thick, edge cracked specimen containing a bond line.

  17. Distributed bragg reflector resonators with cylindrical symmetry and extremely high Q-factors.

    PubMed

    Tobar, Michael E; le Floch, Jean-Michel; Cros, Dominique; Hartnett, John G

    2005-01-01

    A simple non-Maxwellian method is presented that allows the approximate solution of all the dimensions of a multilayered dielectric TE0qp mode cylindrical resonant cavity that constitutes a distributed Bragg reflection (DBR) resonator. The analysis considers an arbitrary number of alternating dielectric and free-space layers of cylindrical geometry enclosed by a metal cylinder. The layers may be arranged along the axial direction, the radial direction, or both. Given only the aspect ratio of the cavity, the desired frequency and the dielectric constants of the material layers, the relevant dimensions are determined from only a set of simultaneous equations, and iterative techniques are not required. The formulas were verified using rigorous method of lines (MoL) calculations and previously published experimental work. We show that the simple approximation gives dimensions close to the values of the optimum Bragg reflection condition determined by the rigorous analysis. The resulting solution is more compact with a higher Q-factor when compared to other reported cylindrical DBR structures. This is because it properly takes into account the effect of the aspect ratio on the Bragg antiresonance condition along the z-axis of the resonator. Previous analyses assumed the propagation in the z-direction was independent of the aspect ratio, and the layers of the Bragg reflector were a quarter of a wavelength thick along the z-direction. When the aspect ratio is properly taken into account, we show that the thickness of the Bragg reflectors are equivalent to the thickness of plane wave Bragg reflectors (or quarter wavelength plates). Thus it turns out that the sizes of the reflectors are related to the free-space propagation constant rather than the propagation constant in the z-direction. PMID:15742559

  18. [Spatial distribution of soil moisture and salinity and their influence factors in the farmland of Manas River catchment, Northwest China].

    PubMed

    Shen, Hao; Abuduwaili, Jilili

    2015-03-01

    Applying methods of statistics and geo-statistics, Manas River catchment was selected as the research area to study the spatial distribution of soil moisture and salinity in the soil profile as. well as their influence factors. The coupling relationship between soil moisture and salinity presented in the spatial distribution was explored as well. The result showed that the soil moisture was overall at a low level (varying from 14.2% to 20.9%), while the salinity was relatively high (about 6.00-9.15 g . kg-1). The soil profile distribution of water and salt contents both showed a trend of bottom accumulation. The variation of soil water moisture was moderate, while that of salt content was strong. Soil salinity and moisture of all layers showed strong spatial autocorrelation, which were mainly affected by structural factors. The horizontal distribution patterns of water and salt contents were irregular, and were constrained by factors like terrain and landforms, etc. Disturbed by human activities, the coupling relation of soil moisture and salinity became much more complex, but their spatial distribution variation was synchronized to some extent. PMID:26211058

  19. The changing food outlet distributions and local contextual factors in the United States

    PubMed Central

    2014-01-01

    Background Little is known about the dynamics of the food outlet distributions associated with local contextual factors in the U.S. This study examines the changes in food stores/services at the 5-digit Zip Code Tabulated Area (ZCTA5) level in the U.S., and assesses contextual factors associated with the changes. Methods Data from 27,878 ZCTA5s in the contiguous United States without an extreme change in the number of 6 types of food stores/services (supermarkets, small-size grocery stores, convenience stores, fresh/specialty food markets, carry-out restaurants, and full-service restaurants) were used. ZCTA5s’ contextual factors were from the 2000 Census. Numbers of food stores/services were derived from the Census Business Pattern databases. Linear regression models assessed contextual factors’ influences (racial/ethnic compositions, poverty rate, urbanization level, and foreign-born population%) on 1-year changes in food stores/services during 2000–2001, adjusted for population size, total business change, and census regions. Results Small-size grocery stores and fresh/specialty food markets increased more and convenience stores decreased more in Hispanic-predominant than other areas. Among supermarket-free places, new supermarkets were less likely to be introduced into black-predominant than white-predominant areas (odds ratio (OR) = 0.52, 95% CI = 0.30-0.92). However, among areas without the following type of store at baseline, supermarket (OR = 0.48 (0.33-0.70)), small-size grocery stores (OR = 1.32 (1.08-1.62)), and fresh/specialty food markets (OR = 0.70 (0.53-0.92)) were less likely to be introduced into areas of low foreign-born population than into areas of high foreign-born population. Higher poverty rate was associated with a greater decrease in supermarket, a less decrease in small-size grocery stores, and a less increase in carry-out restaurants (all p for trends <0.001). Urban areas experienced more increases in full

  20. Host-Specific Interactions with Environmental Factors Shape the Distribution of Symbiodinium across the Great Barrier Reef

    PubMed Central

    Tonk, Linda; Sampayo, Eugenia M.; Weeks, Scarla; Magno-Canto, Marites; Hoegh-Guldberg, Ove

    2013-01-01

    Background The endosymbiotic dinoflagellates (genus Symbiodinium) within coral reef invertebrates are critical to the survival of the holobiont. The genetic variability of Symbiodinium may contribute to the tolerance of the symbiotic association to elevated sea surface temperatures (SST). To assess the importance of factors such as the local environment, host identity and biogeography in driving Symbiodinium distributions on reef-wide scales, data from studies on reef invertebrate-Symbiodinium associations from the Great Barrier Reef (GBR) were compiled. Methodology/Principal Findings The resulting database consisted of 3717 entries from 26 studies. It was used to explore ecological patterns such as host-specificity and environmental drivers structuring community complexity using a multi-scalar approach. The data was analyzed in several ways: (i) frequently sampled host species were analyzed independently to investigate the influence of the environment on symbiont distributions, thereby excluding the influence of host specificity, (ii) host species distributions across sites were added as an environmental variable to determine the contribution of host identity on symbiont distribution, and (iii) data were pooled based on clade (broad genetic groups dividing the genus Symbiodinium) to investigate factors driving Symbiodinium distributions using lower taxonomic resolution. The results indicated that host species identity plays a dominant role in determining the distribution of Symbiodinium and environmental variables shape distributions on a host species-specific level. SST derived variables (especially SSTstdev) most often contributed to the selection of the best model. Clade level comparisons decreased the power of the predictive model indicating that it fails to incorporate the main drivers behind Symbiodinium distributions. Conclusions/Significance Including the influence of different host species on Symbiodinium distributional patterns improves our understanding

  1. Quantifying the effects of geographical and environmental factors on distribution of stream bacterioplankton within nature reserves of Fujian, China.

    PubMed

    Wang, Yongming; Yang, Jun; Liu, Lemian; Yu, Zheng

    2015-07-01

    Bacterioplankton are important components of freshwater ecosystems and play essential roles in ecological functions and processes; however, little is known about their geographical distribution and the factors influencing their ecology, especially in stream ecosystems. To examine how geographical and environmental factors affect the composition of bacterioplankton communities, we used denaturing gradient gel electrophoresis and clone sequencing to survey bacterioplankton communities in 31 samples of streamwater from seven nature reserves in Fujian province, southeast China. Our results revealed that dominant bacterioplankton communities exhibited a distinct geographical pattern. Further, we provided evidence for distance decay relationships in bacterioplankton community similarity and found similar community gradients in response to elevation and latitude. Both redundancy analyses and Mantel tests showed that bacterioplankton community composition was significantly correlated with both environmental (electrical conductivity, total phosphorus, and PO4-P) and geographical factors (latitude, longitude, and elevation). Variance partitioning further showed that the joint effect of geographical and environmental factors explained the largest proportion of the variation in distribution of bacterioplankton communities (13.6 %), followed by purely geographical factors (11.2 %), and purely environmental factors (0.6 %). The Betaproteobacteria were the most common taxa in the streams, followed by Firmicutes and Gammaproteobacteria. Therefore, our results suggest that the biogeographical patterns of stream bacterioplankton communities across the Fujian nature reserves are more influenced by geographical factors than by local physicochemical properties. PMID:25787217

  2. Examining Factor Score Distributions to Determine the Nature of Latent Spaces

    ERIC Educational Resources Information Center

    Steinley, Douglas; McDonald, Roderick P.

    2007-01-01

    Similarities between latent class models with K classes and linear factor models with K-1 factors are investigated. Specifically, the mathematical equivalence between the covariance structure of the two models is discussed, and a Monte Carlo simulation is performed using generated data that represents both latent factors and latent classes with…

  3. Processing factor for a selected group of pesticides in a wine-making process: distribution of pesticides during grape processing.

    PubMed

    Pazzirota, T; Martin, L; Mezcua, M; Ferrer, C; Fernandez-Alba, A R

    2013-01-01

    The processing factors (the pesticide concentration found in the wine/pesticide concentration found in grapes) of acetamiprid, azoxistrobin, carbaril, carbendazime, cyprodinil, dimethoate, dimethormorf, imazalil, imidacloprid, kresoxim methyl, penconazole, procymidone and thiabendazole were determined in a wine-making process. Pesticide analysis was performed using a multi-residue method for the determination of different pesticides both in wine and in grapes by extraction with acetonitrile followed by LC/MS. The pesticide distribution was studied for each step of the process, and the pesticide processing factors were calculated and found to vary among the different pesticides studied. pKow was found to affect a pesticide's processing factor; a linear correlation was obtained for all pesticide processing factors, except for dimethoate, which was the most water soluble. However, no correlation was found between the processing factor and the water solubility of pesticides. PMID:23875669

  4. Snow modeling in the Klamath River Basin: understanding the factors controlling snow distribution and melt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Point and spatially distributed models have been applied to the 4053 km2 Sprague River Basin which is one of three main tributaries to the Upper Klamath Basin in Southern Oregon, USA. The simulations cover entire water years to understand the physics controlling snow distribution during the accumul...

  5. Neutron distribution, electric dipole polarizability and weak form factor of 48Ca from chiral effective field theory

    NASA Astrophysics Data System (ADS)

    Wendt, Kyle

    2016-03-01

    How large is the 48Ca nucleus? While the electric charge distribution of this nucleus was accurately measured decades ago, both experimental and ab initio descriptions of the neutron distribution are deficient. We address this question using ab initio calculations of the electric charge, neutron, and weak distributions of 48Ca based on chiral effective field theory. Historically, chiral effective field theory calculations of systems larger than 4 nucleons have been plagued by strong systematic errors which result in theoretical descriptions that are too dense and over bound. We address these errors using a novel approach that permits us to accurately reproduce binding energy and charge radius of 48Ca, and to constrain electroweak observables such as the neutron radius, electric dipole polarizability, and the weak form factor. For a full list of contributors to this work, please see ``Neutron and weak-charge distributions of the 48Ca nucleus,'' Nature Physics (2015) doi:10.1038/nphys3529.

  6. Von Willebrand factor regulates complement on endothelial cells.

    PubMed

    Noone, Damien G; Riedl, Magdalena; Pluthero, Fred G; Bowman, Mackenzie L; Liszewski, M Kathryn; Lu, Lily; Quan, Yi; Balgobin, Steve; Schneppenheim, Reinhard; Schneppenheim, Sonja; Budde, Ulrich; James, Paula; Atkinson, John P; Palaniyar, Nades; Kahr, Walter H A; Licht, Christoph

    2016-07-01

    Atypical hemolytic uremic syndrome and thrombotic thrombocytopenic purpura have traditionally been considered separate entities. Defects in the regulation of the complement alternative pathway occur in atypical hemolytic uremic syndrome, and defects in the cleavage of von Willebrand factor (VWF)-multimers arise in thrombotic thrombocytopenic purpura. However, recent studies suggest that both entities are related as defects in the disease-causing pathways overlap or show functional interactions. Here we investigate the possible functional link of VWF-multimers and the complement system on endothelial cells. Blood outgrowth endothelial cells (BOECs) were obtained from 3 healthy individuals and 2 patients with Type 3 von Willebrand disease lacking VWF. Cells were exposed to a standardized complement challenge via the combination of classical and alternative pathway activation and 50% normal human serum resulting in complement fixation to the endothelial surface. Under these conditions we found the expected release of VWF-multimers causing platelet adhesion onto BOECs from healthy individuals. Importantly, in BOECs derived from patients with von Willebrand disease complement C3c deposition and cytotoxicity were more pronounced than on BOECs derived from normal individuals. This is of particular importance as primary glomerular endothelial cells display a heterogeneous expression pattern of VWF with overall reduced VWF abundance. Thus, our results support a mechanistic link between VWF-multimers and the complement system. However, our findings also identify VWF as a new complement regulator on vascular endothelial cells and suggest that VWF has a protective effect on endothelial cells and complement-mediated injury. PMID:27236750

  7. Bimodal Distribution of Tropical Cyclogenesis in the Caribbean: Characteristics and Environmental Factors.

    NASA Astrophysics Data System (ADS)

    Inoue, Masamichi; Handoh, Itsuki C.; Bigg, Grant R.

    2002-10-01

    Tropical cyclogenesis critically depends on the presence of warm water at the sea surface. For the North Atlantic basin as a whole, the tropical storm season starts in May, peaks in September, and then declines, generally following the seasonal warming and cooling of sea surface temperature. In the Caribbean, in contrast, there is a distinct bimodal distribution in the number of tropical storms formed, with peaks in June and October separated by a significant minimum in July. The timing of the observed minimum in tropical cyclogenesis appears to be related to the strengthening of the easterly trade winds over the Caribbean associated with the onset of the so-called veranillo, or midsummer drought (MSD), previously recognized over south-central Mexico, Central America, and parts of the Caribbean. It appears that the observed minimum in cyclogenesis is caused by a combination of environmental factors related to the strengthening of the easterly trade winds across the Caribbean Basin. The strengthening easterly trade winds and their associated changes in wind stress curl give rise to enhanced upwelling in the southwestern Caribbean. This appears to trigger an enhanced local atmosphere-ocean coupling, giving rise to very unfavorable conditions in several environmental variables including cooler sea surface temperature (SST), higher sea level pressure (SLP), increase in outgoing longwave radiation (OLR), and decrease in precipitable water content (PRW). Moreover, strengthening trade winds result in increases in tropospheric vertical wind shear (VSH). Except for OLR, these environmental variables become least favorable for southwestern Caribbean cyclogenesis in July. In contrast, the transition from weak to intense convective activity in the eastern Pacific results in weaker trade winds in the Caribbean in October. The resulting westerly wind anomalies lead to weakening upwelling, warmer SST, enhanced convection, and moist air coupled with weaker VSH in the southwestern

  8. [Distribution, seasonal variation and influence factors of dissolved inorganic arsenic in the Sanggou Bay].

    PubMed

    Li, Lei; Ren, Jing-Ling; Liu, Su-Mei; Jiang, Zeng-Jie; Du, Jin-Zhou; Fang, Jian-Guang

    2014-07-01

    The biogeochemical behavior of arsenic in the aquatic environment has already captured the attentions of scientists due to its complex forms and toxicity. Four cruises were carried out in April, August, October 2011 and January 2012 in the Sanggou Bay. The concentrations of total dissolved inorganic arsenic (TDIAs, TDIAs = [ As(5+] + [As(3+)]) and arsenite (As(3+)) were measured by Hydride Generation-Atomic Fluorescence Spectrometry (HG-AFS). The concentrations of TDIAs ranged from 3.4-12.4 nmol x L(-1) in April, 8.9-16.9 nmol x L(-1) in August, 14.7-21.3 nmol x L(-1) in October and 13.8-21.9 nmol x L(-1) in January. The concentrations of arsenite ranged from 0.3-2.1 nmol x L(-1), 0.4-3.8 nmol x L(-1), 1.8-4.0 nmol x L(-1) and 0.3-2.9 nmol x L(-1) during four cruises, respectively. The concentrations of TDIAs in spring and summer were lower than those in autumn and winter, and high values of TDIAs appeared in the bay-mouth and the coastal estuary. The concentrations of arsenite in spring and winter were lower than those in summer and autumn. The maximum As(3+)/TDIAs ratios appeared in summer. The mean value of TDIAs in the Sanggou Bay was (13.9 +/- 4.7) nmol x L(-1), which was lower than the national primary drinking in water Standards from USEPA and met the first grade water quality based on the environmental quality standards for surface water of China. It indicates that there is no obvious anthropogenic pollution. The concentrations of TDIAs in the Sanggou Bay were lower than those in the Ailian Bay and the Lidao Bay in spring and summer due to the different hydrological environments and terrestrial inputs. Riverine input, incursion of Yellow Sea and biological activities were the three main factors impacting the distribution of TDIAs in the Sanggou Bay, and the influence of aquaculture activities was particularly significant. The enrichment of arsenic by aquaculture may lead to potential ecological crisis and food safety problems, and need to be paid more

  9. Factors responsible for the patchy distribution of natural soil water repellency in Mediterranean semiarid forest

    NASA Astrophysics Data System (ADS)

    Lozano, E.; Jiménez-Pinilla, P.; Mataix-Solera, J.; González-Pérez, J. A.; García-Orenes, F.; Torres, M. P.; Arcenegui, V.; Mataix-Beneyto, J.

    2012-04-01

    Soil water repellency (WR) is commonly observed in forest areas showing wettable and water repellent patches with high spatial variability. This has important hydrological implications; in semiarid areas where water supply is limited, even slight WR may play an important role in infiltration patterns and distribution of water into the soil (Mataix-Solera et al., 2007). It has been proposed that the origin of WR is the release of organic compounds from different plants species and sources (due to waxes and other organic substances in their tissues; Doerr et al., 1998). However, the relationship between WR and plants may not always be a direct one: a group of fungi (mainly mycorrhizal fungi) and microorganisms could be also responsible for WR. The aim of this research is to study the relationships between WR in soils under different plant cover with selected soil properties and the quantity of fungi and their exudates. The study area is located in Southeast Spain, "Sierra de la Taja" near Pinoso (Alicante)), with a semiarid Mediterranean climate (Pm=260mm). Samples were taken in September 2011, when WR is normally strongest after summer drought. Soil samples were collected from the first 2.5cm of the mineral A horizon at microsites beneath each of the four most representative species (Pinus halepensis, Rosmarinus officinalis, Quercus. rotundifolia and Cistus albidus; n=15 per specie) and 5 samples from bare soil with no influence of any species. Different soil parameters were analyzed; water content, soil organic mater content (SOM), pH, WR, easily extractable glomalin (EEG), total mycelium and extractable lipids. The occurrence of WR was higher under P. halepensis (87% of samples) and Q. rotundifolia (60% of samples). Positive significant correlations were found between WR and SOM content for all species, with the best correlations for Pinus and Quercus (r=0.855**, r= 0.934** respectively). In addition, negative significant correlations were found between WR and p

  10. Programmes for advance distribution of misoprostol to prevent post-partum haemorrhage: a rapid literature review of factors affecting implementation.

    PubMed

    Smith, Helen J; Colvin, Christopher J; Richards, Esther; Roberson, Jeffrey; Sharma, Geeta; Thapa, Kusum; Gülmezoglu, A Metin

    2016-02-01

    Recent efforts to prevent post-partum haemorrhage (PPH) in low-income countries have focused on providing women with access to oral misoprostol during home birth. The WHO recommends using lay health workers (LHWs) to administer misoprostol in settings where skilled birth attendants are not available. This review synthesizes current knowledge about the barriers and facilitators affecting implementation of advance community distribution of misoprostol to prevent PPH, where misoprostol may be self-administered or administered by an LHW.We searched for and summarized available empirical evidence, and collected primary data from programme stakeholders about their experiences of programme implementation.We present key outcomes and features of advanced distribution programmes that are in operation or have been piloted globally. We categorized factors influencing implementation into those that operate at the health system level, factors related to the community and policy context and those factors more closely connected to the end user.Debates around advance distribution have centred on the potential risks and benefits of making misoprostol available to pregnant women and community members during pregnancy for administration in the home. However, the risks of advance distribution appear manageable and the benefits of self-administration, especially for women who have little chance of expert care for PPH, are considerable. PMID:25797470

  11. Jamaica Bay studies VII: Factors affecting the distribution and abundance of ducks in a New York estuary

    NASA Astrophysics Data System (ADS)

    Burger, Joanna; Trout, J. Richard; Wander, Wade; Ritter, Glenn S.

    1984-12-01

    The abundance and distribution of ducks (Anatini, Cairinini, Aythyini, Mergini, Oxyurini) were examined at Jamaica Bay Wildlife Refuge, a coastal estuary on Long Island, New York. The refuge contains a variety of tidal habitats as well two freshwater impoundments. The largest concentrations of diving ducks were present in March and April, and from October through December; while the largest concentrations of dabbling ducks were present from June through December. Thus, diving ducks used the refuge on migration whereas dabbling ducks used the refuge during and following the breeding season. Time of year was thus the most significant factor affecting distribution and abundance. Some species were present all year, including Black Duck Anas rubripes, Mallard A. platyrhynchos, Gadwall A. strepera, and Ruddy Duck Oxyura jamaicensis. Although both dabblers and divers used all areas of the bay, dabblers used both ponds while divers used only the East Pond. Dabbling ducks concentrated in the bay at low tide, and on the ponds at high tide. There were more divers on the bay on a falling tide although tide direction did not influence the abundance or distribution of dabblers. Temperature and wind variables influenced the distribution of all ducks: they used the bay at low temperatures, and rafted in large flocks on the bay in intermediate, Northwest winds. Only the numbers and distribution of dabblers were significantly influenced by cloud cover. We conclude that abiotic factors influence the abundance and distribution of ducks on Jamaica Bay Wildlife Refuge, and that tidal factors should be considered when managing migratory or wintering populations of ducks.

  12. Factors Affecting the Distribution of Perfluorinated Compounds in Sediments from Lake Shihwa, Korea

    EPA Science Inventory

    Perfluorinated compounds (PFCs) are ubiquitously distributed in various environmental media including water, soil, sediment, and biota. PFCs have also been shown to biomagnify in both aquatic and terrestrial environments. Lake Shihwa is an artificial saltwater lake, located on ...

  13. Exclusive muon-pair production in ultrarelativistic heavy-ion collisions: Realistic nucleus charge form factor and differential distributions

    SciTech Connect

    Klusek-Gawenda, M.; Szczurek, A.

    2010-07-15

    The cross sections for exclusive muon-pair production in nucleus-nucleus collisions are calculated and several differential distributions are shown. Realistic (Fourier transform of charge density) charge form factors of nuclei are used and the corresponding results are compared with the cross sections calculated with monopole form factor often used in the literature and discussed recently in the context of higher-order QED corrections. Absorption effects are discussed and quantified. The cross sections obtained with realistic form factors are significantly smaller than those obtained with the monopole form factor. The effect is bigger for large muon rapidities and/or large muon transverse momenta. The predictions for the STAR and PHENIX collaboration measurements at RHIC as well as the ALICE and CMS collaborations at LHC are presented.

  14. Expression, purification, and characterization of protective MPT64 antigen protein and identification of its multimers isolated from nontoxic Mycobacterium tuberculosis H37Ra.

    PubMed

    Chu, Teng-Ping J; Yuann, Jeu-Ming P

    2011-05-01

    MPT64, a secreted protein of Mycobacterium tuberculosis (MTB), stimulates the immune reactions within cells and is a protective antigen that is lost by the bacilli Calmette-Guérin (BCG) vaccine during propagation. To minimize the toxicity caused by MTB, we used the MPT64 gene encoded by nontoxic H37Ra MTB to carry out genetic expansion via polymerase chain reaction and gene clone MPT64. The plasmid DNA encoded MPT64 was expressed at 20°C for 22 H, and a large quantity of MPT64 was obtained. In the absence of urea, MPT64 multimers with subunits being covalently connected via disulfide bonds were detected by Western blot showing strong protein-protein interactions, as evidenced by the formation of MPT64 tetramers. Finally, with urea of decreasing concentrations, we refolded MPT64 purified in the presence of urea and determined its secondary structures using circular dichroism. MPT64 was found to contain 2.2% α-helix, 50.9% β-sheet, 19.5% turn, and 27.4% random coil. The molecular weight of MPT64 was determined by a matrix-assisted laser desorption ionization-time of flight mass spectrometer and found to be 23,497 Da, very close to the theoretical molecular weight of MPT64. The results presented here provide a sound basis for future biochemical and biophysical studies of MPT64 or any other proteins encoded by nontoxic H37Ra MTB. PMID:21679242

  15. DESICCATION AND OTHER FACTORS AFFECTING THE UPPER INTERTIDAL DISTRIBUTION OF EELGRASS IN YAQUINA BAY, OR

    EPA Science Inventory

    Eelgrass (Zostera marina) in Pacific Northwest is primarily intertidal, yet little research has been done on what factors control its upper intertidal growth boundary. In July 2000 a two year study was initiated in Yaquina Bay (Newport, OR) to evaluate the effects of four factor...

  16. Distribution patterns and possible influencing factors of As speciation in ornithogenic sediments from the Ross Sea region, East Antarctica.

    PubMed

    Lou, Chuangneng; Liu, Xiaodong; Liu, Wenqi; Wu, Libin; Nie, Yaguang; Emslie, Steven D

    2016-05-15

    Ornithogenic sediments are rich in toxic As (arsenic) compounds, posing a potential threat to local ecosystems. Here we analyzed the distribution of As speciation in three ornithogenic sediment profiles (MB6, BI and CC) collected from the Ross Sea region, East Antarctica. The distributions of total As and total P (phosphorus) concentrations were highly consistent in all three profiles, indicating that guano input is a major factor controlling total As distribution in the ornithogenic sediments. The As found in MB6 and CC is principally As(V) (arsenate), in BI As(III) (arsenite) predominates, but the As in fresh guano is largely composed of DMA (dimethylarsinate). The significant difference of As species between fresh guano and ornithogenic sediment samples may be related to diagenetic processes after deposition by seabirds. Based on analysis of the sedimentary environment in the studied sediments, we found that the redox conditions have an obvious influence on the As speciation distribution. Moreover, the distributions of As(III) and chlorophyll a in the MB6 and BI profiles are highly consistent, demonstrating that aquatic algae abundance may also influence the distribution patterns of As speciation in the ornithogenic sediments. PMID:26930318

  17. Geographical Distribution Patterns of Iodine in Drinking-Water and Its Associations with Geological Factors in Shandong Province, China

    PubMed Central

    Gao, Jie; Zhang, Zhijie; Hu, Yi; Bian, Jianchao; Jiang, Wen; Wang, Xiaoming; Sun, Liqian; Jiang, Qingwu

    2014-01-01

    County-based spatial distribution characteristics and the related geological factors for iodine in drinking-water were studied in Shandong Province (China). Spatial autocorrelation analysis and spatial scan statistic were applied to analyze the spatial characteristics. Generalized linear models (GLMs) and geographically weighted regression (GWR) studies were conducted to explore the relationship between water iodine level and its related geological factors. The spatial distribution of iodine in drinking-water was significantly heterogeneous in Shandong Province (Moran’s I = 0.52, Z = 7.4, p < 0.001). Two clusters for high iodine in drinking-water were identified in the south-western and north-western parts of Shandong Province by the purely spatial scan statistic approach. Both GLMs and GWR indicated a significantly global association between iodine in drinking-water and geological factors. Furthermore, GWR showed obviously spatial variability across the study region. Soil type and distance to Yellow River were statistically significant at most areas of Shandong Province, confirming the hypothesis that the Yellow River causes iodine deposits in Shandong Province. Our results suggested that the more effective regional monitoring plan and water improvement strategies should be strengthened targeting at the cluster areas based on the characteristics of geological factors and the spatial variability of local relationships between iodine in drinking-water and geological factors. PMID:24852390

  18. Proteoglycan distribution in lesions of atherosclerosis depends on lesion severity, structural characteristics, and the proximity of platelet-derived growth factor and transforming growth factor-beta.

    PubMed Central

    Evanko, S. P.; Raines, E. W.; Ross, R.; Gold, L. I.; Wight, T. N.

    1998-01-01

    The accumulation of proteoglycans (PGs) in atherosclerosis contributes to disease progression and stenosis and may partly depend on local regulation by growth factors such as platelet-derived growth factor (PDGF) and transforming growth factor (TGF)-beta. In this study, the distribution of the major extracellular PGs is compared with that of PDGF and TGF-beta isoforms in developing lesions of atherosclerosis from hypercholesterolemic nonhuman primates. Strong immunostaining for decorin, biglycan, versican, and hyaluronan is observed in both intermediate and advanced lesions. Perlecan staining is weak in intermediate lesions but strong in advanced lesions in areas bordering the plaque core. Immunostaining for PDGF-B and TGF-beta1 is particularly prominent in macrophages in intermediate and advanced lesions. In contrast, TGF-beta2 and TGF-beta3 and PDGF-A are present in both macrophages and smooth muscle cells. Overall, PG deposits parallel areas of intense growth factor immunostaining, with trends in relative localization that suggest interrelationships among certain PGs and growth factors. Notably, decorin and TGF-beta1 are distributed similarly, predominantly in the macrophage-rich core, whereas biglycan is prominent in the smooth muscle cell matrix adjoining TGF-beta1-positive macrophages. Versican and hyaluronan are enriched in the extracellular matrix adjacent to both PDGF- and TGF-beta1-positive cells. These data demonstrate that PG accumulation varies with lesion severity, structural characteristics, and the proximity of PDGF and TGF-beta. Images Figure 1 p537-a Figure 2 p539-a Figure 3 Figure 4 Figure 5 Figure 6 PMID:9466580

  19. Environmental factors prevail over dispersal constraints in determining the distribution and assembly of Trichoptera species in mountain lakes.

    PubMed

    de Mendoza, Guillermo; Ventura, Marc; Catalan, Jordi

    2015-07-01

    Aiming to elucidate whether large-scale dispersal factors or environmental species sorting prevail in determining patterns of Trichoptera species composition in mountain lakes, we analyzed the distribution and assembly of the most common Trichoptera (Plectrocnemia laetabilis, Polycentropus flavomaculatus, Drusus rectus, Annitella pyrenaea, and Mystacides azurea) in the mountain lakes of the Pyrenees (Spain, France, Andorra) based on a survey of 82 lakes covering the geographical and environmental extremes of the lake district. Spatial autocorrelation in species composition was determined using Moran's eigenvector maps (MEM). Redundancy analysis (RDA) was applied to explore the influence of MEM variables and in-lake, and catchment environmental variables on Trichoptera assemblages. Variance partitioning analysis (partial RDA) revealed the fraction of species composition variation that could be attributed uniquely to either environmental variability or MEM variables. Finally, the distribution of individual species was analyzed in relation to specific environmental factors using binomial generalized linear models (GLM). Trichoptera assemblages showed spatial structure. However, the most relevant environmental variables in the RDA (i.e., temperature and woody vegetation in-lake catchments) were also related with spatial variables (i.e., altitude and longitude). Partial RDA revealed that the fraction of variation in species composition that was uniquely explained by environmental variability was larger than that uniquely explained by MEM variables. GLM results showed that the distribution of species with longitudinal bias is related to specific environmental factors with geographical trend. The environmental dependence found agrees with the particular traits of each species. We conclude that Trichoptera species distribution and composition in the lakes of the Pyrenees are governed predominantly by local environmental factors, rather than by dispersal constraints. For

  20. Environmental factors prevail over dispersal constraints in determining the distribution and assembly of Trichoptera species in mountain lakes

    PubMed Central

    de Mendoza, Guillermo; Ventura, Marc; Catalan, Jordi

    2015-01-01

    Aiming to elucidate whether large-scale dispersal factors or environmental species sorting prevail in determining patterns of Trichoptera species composition in mountain lakes, we analyzed the distribution and assembly of the most common Trichoptera (Plectrocnemia laetabilis, Polycentropus flavomaculatus, Drusus rectus, Annitella pyrenaea, and Mystacides azurea) in the mountain lakes of the Pyrenees (Spain, France, Andorra) based on a survey of 82 lakes covering the geographical and environmental extremes of the lake district. Spatial autocorrelation in species composition was determined using Moran’s eigenvector maps (MEM). Redundancy analysis (RDA) was applied to explore the influence of MEM variables and in-lake, and catchment environmental variables on Trichoptera assemblages. Variance partitioning analysis (partial RDA) revealed the fraction of species composition variation that could be attributed uniquely to either environmental variability or MEM variables. Finally, the distribution of individual species was analyzed in relation to specific environmental factors using binomial generalized linear models (GLM). Trichoptera assemblages showed spatial structure. However, the most relevant environmental variables in the RDA (i.e., temperature and woody vegetation in-lake catchments) were also related with spatial variables (i.e., altitude and longitude). Partial RDA revealed that the fraction of variation in species composition that was uniquely explained by environmental variability was larger than that uniquely explained by MEM variables. GLM results showed that the distribution of species with longitudinal bias is related to specific environmental factors with geographical trend. The environmental dependence found agrees with the particular traits of each species. We conclude that Trichoptera species distribution and composition in the lakes of the Pyrenees are governed predominantly by local environmental factors, rather than by dispersal constraints. For

  1. Factors Affecting Crater Size-Frequency Distribution Measurements: Insights Supported by the LRO Mission

    NASA Astrophysics Data System (ADS)

    van der Bogert, C. H.; Hiesinger, H.; Zanetti, M.; Plescia, J. B.; Ostrach, L. R.; Mahanti, P.; Meyer, H. M.; McEwen, A. S.; Pasckert, J. H.; Michael, G.; Kneissl, T.; Robinson, M. S.

    2016-05-01

    CSFD measurements are affected by illumination angle, count area size/slope, secondary cratering, target property effects, and differential degradation. Investigations using LRO data have made progress characterizing and quantifying these factors.

  2. Importance of environmental factors on the richness and distribution of benthic macroinvertebrates in tropical headwater streams

    EPA Science Inventory

    It is essential to understand the interactions between local environmental factors (e.g., physical habitat and water quality) and aquatic assemblages to conserve biodiversity in tropical and subtropical headwater streams. Therefore, we evaluated the relative importance of multipl...

  3. [Influence of environmental factors on the distribution of tree species in the forests of south-eastern Mexico].

    PubMed

    Cortés-Castelán, José C; Islebe, Gerald A

    2005-01-01

    We studied the relationship between the distribution of tree species and environmental factors in the Sian Ka'an Biosphere Reserve, south-eastern Mexico. Our main objective was to examine how changes in microtopography and edaphic factors influence the distribution of tree species of medium and low-statured forests. We established 17 plots of 625 m2 and collected data on spatial distribution of individuals with dbh > or = 5 cm, and the following soil variables: electric conductivity (CE), cationic exchange capacity (CEC), textural class, pH, organic matter (MO), total nitrogen (Nt) and phosphorus availability (P). We used Twinspan to classify the plots and applied indirect (DCA) and direct (CCA) gradient analysis. We found 84 species and 4 433 individuals. MO, texture and CEC varied significantly (p< or =0.05) between the high and low parts. DCA and CCA indicated that the species distribution is strongly influenced by the microtopography gradient and the textural class. Using DCA and CCA exclusively on the data of the low parts, two low statured forest types were identified: one characteristic of low zones (soil slightly basic and high percentage of clay), the other surrounded by medium statured forest (soil slightly acid, high CEC, MO and clay). PMID:17354425

  4. A Model Based on Environmental Factors for Diameter Distribution in Black Wattle in Brazil

    PubMed Central

    Sanquetta, Carlos Roberto; Behling, Alexandre; Dalla Corte, Ana Paula; Péllico Netto, Sylvio; Rodrigues, Aurelio Lourenço; Simon, Augusto Arlindo

    2014-01-01

    This article discusses the dynamics of a diameter distribution in stands of black wattle throughout its growth cycle using the Weibull probability density function. Moreover, the parameters of this distribution were related to environmental variables from meteorological data and surface soil horizon with the aim of finding a model for diameter distribution which their coefficients were related to the environmental variables. We found that the diameter distribution of the stand changes only slightly over time and that the estimators of the Weibull function are correlated with various environmental variables, with accumulated rainfall foremost among them. Thus, a model was obtained in which the estimators of the Weibull function are dependent on rainfall. Such a function can have important applications, such as in simulating growth potential in regions where historical growth data is lacking, as well as the behavior of the stand under different environmental conditions. The model can also be used to project growth in diameter, based on the rainfall affecting the forest over a certain time period. PMID:24932909

  5. Distributed Leadership as a Factor in and Outcome of Teacher Action Learning

    ERIC Educational Resources Information Center

    Dinham, Stephen; Aubusson, Peter; Brady, Laurie

    2008-01-01

    This paper reports an evaluation of Quality Teaching Action Learning (QTAL) projects conducted at New South Wales (NSW), Australia public (state) primary and secondary schools and explores how distributed leadership facilitated and was an outcome of the QTAL projects. The evaluation encompassed all 50 projects at 82 NSW public schools, and nine of…

  6. Spatial Distribution of Soil Organic Carbon and Its Influencing Factors in Desert Grasslands of the Hexi Corridor, Northwest China

    PubMed Central

    Wang, Min; Su, Yongzhong; Yang, Xiao

    2014-01-01

    Knowledge of the distribution patterns of soil organic carbon (SOC) and factors that influence these patterns is crucial for understanding the carbon cycle. The objectives of this study were to determine the spatial distribution pattern of soil organic carbon density (SOCD) and the controlling factors in arid desert grasslands of northwest China. The above- and belowground biomass and SOCD in 260 soil profiles from 52 sites over 2.7×104 km2 were investigated. Combined with a satellite-based dataset of an enhanced vegetation index during 2011–2012 and climatic factors at different sites, the relationships between SOCD and biotic and abiotic factors were identified. The results indicated that the mean SOCD was 1.20 (SD:+/− 0.85), 1.73 (SD:+/− 1.20), and 2.69 (SD:+/− 1.91) kg m−2 at soil depths of 0–30 cm, 0–50 cm, and 0–100 cm, respectively, which was smaller than other estimates in temperate grassland, steppe, and desert-grassland ecosystems. The spatial distribution of SOCD gradually decreased from the southeast to the northwest, corresponding to the precipitation gradient. SOCD increased significantly with vegetation biomass, annual precipitation, soil moisture, clay and silt content, and decreased with mean annual temperature and sand content. The correlation between BGB and SOCD was closer than the correlation between AGB and SOCD. Variables could together explain about 69.8%, 74.4%, and 78.9% of total variation in SOCD at 0–30 cm, 0–50 cm, and 0–100 cm, respectively. In addition, we found that mean annual temperature is more important than other abiotic factors in determining SOCD in arid desert grasslands in our study area. The information obtained in this study provides a basis for accurately estimating SOC stocks and assessing carbon (C) sequestration potential in the desert grasslands of northwest China. PMID:24732375

  7. Quantification of the inhomogeneous distribution of topically applied substances by optical spectroscopy: definition of a factor of inhomogeneity.

    PubMed

    Weigmann, H-J; Schanzer, S; Vergou, T; Antoniou, C; Sterry, W; Lademann, J

    2012-01-01

    The inhomogeneous distribution of topically applied substances due to decisive differences in the skin structure (furrows and wrinkles) affects the efficacy of cosmetic products, in particular sunscreens. The combination of tape stripping and optical spectroscopy results in absorption data, which reflect ex vivo the inhomogeneity of the in vivo distribution of topically applied substances. Based on these data, a factor of inhomogeneity is defined describing the individual distribution of formulations on the skin surface of volunteers. Thus, the influence of different skin surface structures and the influence of different formulations on the distribution of the topically applied substances can be determined. Analyzing the inhomogeneity data on 6 volunteers (5 sunscreens per volunteer), it was found that the influence on the distribution of sunscreens caused by the formulation was higher than the inhomogeneity originating from the differences in the skin surface structure of the volunteers. The method is well suited to characterize, for example, sunscreens and antiaging creams in the process of development, as well as for the evaluation of the final products. PMID:22343548

  8. Distribution of Synechococcus and its phycoerythrin pigment in relation to environmental factors in the East Sea, Korea

    NASA Astrophysics Data System (ADS)

    Yona, Defri; Park, Mi Ok; Oh, Seok Jin; Shin, Woo Chur

    2014-12-01

    Recently, studies on the influences of physico-chemical properties of water masses on the distribution of Synechococcus have been conducted. In addition, it is known that different types of Synechococcus can be identified based on its phycoerythrin (PE) chromophores, which are phycourobilin (PUB) and phycoerythrobilin (PEB). This study observed the abundance of Synechococcus and its phycoerythrin chromophores based on the excitation ratio of PUB and PEB, and also examined the major environmental factors which influence the distribution of Synechococcus in the East Sea during autumn 2011 and spring 2012. Surface distribution showed that the abundance of Synechococcus in autumn was higher than that in spring (6.5 ± 4.7 × 103 cells ml-1 in autumn and 1.2 ± 0.9 × 103 cells ml-1 in spring) when water temperature was warmer and nutrient level was higher. Vertical distribution of Synechococcus abundance showed sub-surface maxima for both seasons between 10-30 m depth. Surface distribution of the PUBEX:PEBEX ratio was found in a slightly similar range between autumn and spring (0.83-1.45 in autumn and 0.82-1.34 in spring). Vertical distribution of the PUBEX:PEBEX ratio ranged between 0.77-1.57 and 0.82-1.42 in autumn and spring, respectively. This study is one of the very few studies that examined the PUBEX:PEBEX ratio in the natural samples and found three different types of Synechococcus based on its PUBEX:PEBEX ratio: high PUBEX:PEBEX ratios (> 1) in warm surface layers and in the deeper layers for both seasons; low PUBEX:PEBEX ratios (< 1) in the surface layer in autumn; and a few PUB-lacking Synechococcus. The distribution of the PUBEX:PEBEX ratio was clearly associated with temperature and salinity in which a low PUBEX:PEBEX ratio coincided with colder and less saline water, and vice versa.

  9. Distributions and impact factors of antimony in topsoils and moss in Ny-Ålesund, Arctic.

    PubMed

    Jia, Nan; Sun, Liguang; He, Xin; You, Kehua; Zhou, Xin; Long, Nanye

    2012-12-01

    The distribution of antimony (Sb) in topsoil and moss (Dicranum angustum) in disturbed and undisturbed areas, as well as coal and gangue, in Ny-Ålesund, Arctic was examined. Results show that the weathering of coal bed could not contribute to the increase of Sb concentrations in topsoil and moss in the study area. The distribution of Sb is partially associated with traffic and historical mining activities. The occurrence of the maximum Sb concentration is due to the contribution of human activities. In addition, the decrease of Sb content in topsoil near the coastline may be caused by the washing of seawater. Compared with topsoils, moss could be a useful tool for monitoring Sb in both highly and lightly polluted areas. PMID:22885219

  10. Factors affecting the distribution of natural and anthropogenic radionuclides in the coastal Burullus Lake.

    PubMed

    El-Reefy, H I; Badran, H M; Sharshar, T; Hilal, M A; Elnimr, T

    2014-08-01

    In the present study, measurements of naturally occurring radioactive materials and (137)Cs activity in sediment were conducted for locations covering the entire Burullus Lake in order to gather information about radionuclides mobility and distribution. Low-background γ-spectrometry was employed to determine the activity concentrations of water and sediment samples. The activity concentrations of (226)Ra and (232)Th are close to uniform distribution in the lake environment. Among the different physical and chemical characteristics measured for water and sediment, only salinity and total organic matter content have the potential to affect the mobility of (137)Cs and (40)K. The results suggest that these two radionuclides are attached to different mobile particulates. Increasing salinity tends to strengthen the adsorption of (137)Cs and solubilization of (40)K in sediment. On the other hand, sediment with high organic matter content traps (137)Cs and (40)K associated particulates to bottom sediment. PMID:24657852

  11. Reduction of spatial distribution of risk factors for transportation of contaminants released by coal mining activities.

    PubMed

    Karan, Shivesh Kishore; Samadder, Sukha Ranjan

    2016-09-15

    It is reported that water-energy nexus composes two of the biggest development and human health challenges. In the present study we presented a Risk Potential Index (RPI) model which encapsulates Source, Vector (Transport), and Target risks for forecasting surface water contamination. The main aim of the model is to identify critical surface water risk zones for an open cast mining environment, taking Jharia Coalfield, India as the study area. The model also helps in feasible sampling design. Based on spatial analysis various risk zones were successfully delineated. Monthly RPI distribution revealed that the risk of surface water contamination was highest during the monsoon months. Surface water samples were analysed to validate the model. A GIS based alternative management option was proposed to reduce surface water contamination risk and observed 96% and 86% decrease in the spatial distribution of very high risk areas for the months June and July respectively. PMID:27240204

  12. Complex interactions between dietary and genetic factors impact lycopene metabolism and distribution

    PubMed Central

    Moran, Nancy E.; Erdman, John W.; Clinton, Steven K.

    2013-01-01

    Intake of lycopene, a red, tetraterpene carotenoid found in tomatoes is epidemiologically associated with a decreased risk of chronic disease processes, and lycopene has demonstrated bioactivity in numerous in vitro and animal models. However, our understanding of absorption, tissue distribution, and biological impact in humans remains very limited. Lycopene absorption is strongly impacted by dietary composition, especially the amount of fat. Concentrations of circulating lycopene in lipoproteins may be further influenced by a number of variations in genes related to lipid absorption and metabolism. Lycopene is not uniformly distributed among tissues, with adipose, liver, and blood being the major body pools, while the testes, adrenals, and liver have the greatest concentrations compared to other organs. Tissue concentrations of lycopene are likely dictated by expression of and genetic variation in lipoprotein receptors, cholesterol transporters, and carotenoid metabolizing enzymes, thus impacting lycopene accumulation at target sites of action. The novel application of genetic evaluation in concert with lycopene tracers will allow determination of which genes and polymorphisms define individual lycopene metabolic phenotypes, response to dietary variables, and ultimately determine biological and clinical outcomes. A better understanding of the relationship between diet, genetics, and lycopene distribution will provide necessary information to interpret epidemiological findings more accurately and to design effective, personalized clinical nutritional interventions addressing hypotheses regarding health outcomes. PMID:23845854

  13. Factors determining the most efficient spray distribution for marine cloud brightening

    PubMed Central

    Connolly, P. J.; McFiggans, G. B.; Wood, R.; Tsiamis, A.

    2014-01-01

    We investigate the sensitivity of marine cloud brightening to the properties of the added salt particle distribution using a cloud parcel model, with an aim to address the question of, ‘what is the most efficient particle size distribution that will produce a desired cooling effect?’ We examine the effect that altering the aerosol particle size distribution has on the activation and growth of drops, i.e. the Twomey effect alone, and do not consider macrophysical cloud responses that may enhance or mitigate the Twomey effect. For all four spray generation methods considered, Rayleigh jet; Taylor cone jet; supercritical fluid; and effervescent spray, salt particles within the median dry diameter range Dm=30–100 nm are the most effective range of sizes. The Rayleigh jet method is also the most energy efficient overall. We also find that care needs to be taken when using droplet activation parametrizations: for the concentrations considered, Aitken particles do not result in a decrease in the total albedo, as was found in a recent study, and such findings are likely to be a result of the parametrizations' inability to simulate the effect of swollen aerosol particles. Our findings suggest that interstitial aerosol particles play a role in controlling the albedo rather than just the activated cloud drops, which is an effect that the parametrization methods do not consider. PMID:25404674

  14. Saproxylic Beetle Assemblage Selection as Determining Factor of Species Distributional Patterns: Implications for Conservation

    PubMed Central

    Galante, E.; Micó, E.

    2016-01-01

    The knowledge of the distributional patterns of saproxylic beetles is essential for conservation biology due to the relevance of this fauna in the maintenance of ecological processes and the endangerment of species. The complex community of saproxylic beetles is shaped by different assemblages that are composed of species linked by the microhabitats they use. We evaluate how different the species distribution patterns that are obtained can be, depending on the analyzed assemblage and to what extent these can affect conservation decisions. Beetles were sampled using hollow emergence and window traps in three protected areas of the Iberian Peninsula. Species richness, composition, and diversity turnover were analyzed for each sampling method and showed high variation depending on the analyzed assemblage. Beta diversity was clearly higher among forests for the assemblage captured using window traps. This method collects flying insects from different tree microhabitats and its captures are influenced by the forest structuring. Within forests, the assemblages captured by hollow emergence traps, which collect the fauna linked to tree hollows, showed the largest turnover of species, as they are influenced by the characteristics of each cavity. Moreover, the selection of the forest showing the highest species richness strongly depended on the studied assemblage. This study demonstrates that differences in the studied assemblages (group of species co-occurring in the same habitat) can also lead to significant differences in the identified patterns of species distribution and diversity turnover. This fact will be necessary to take into consideration when making decisions about conservation and management. PMID:27252483

  15. Benthic foraminiferal distributions on the Uruguayan continental margin (South-western Atlantic) and controlling environmental factors

    NASA Astrophysics Data System (ADS)

    de Mello, Camila; Burone, Leticia; Ortega, Leonardo; Franco-Fraguas, Paula; Lahuerta, Nuria; Mahiques, Michel; Marin, Yamandu

    2014-12-01

    The data on benthic foraminifera analysed from 110 box-core samples collected on the Uruguayan continental margin (outer shelf and upper and middle slope, between 36.54-34.64°S and 51.66-53.71°W) were used to evaluate the distribution of the benthic foraminiferal fauna and its relationship with selected abiotic parameters. Primary productivity (PP) and the organic flux (Jz) reaching the sea floor were also estimated for comparison with the foraminiferal distributions. The study area was characterised by elevated PP and Jz values, mainly in the southernmost region, which were associated with thermohaline fronts due to the presence of the Subtropical Shelf Front. The dominant identified taxa were Rhumblerella sepetibaensis (this is the first study recording the ecology of this species) and the opportunistic species Epistominella exigua, Bulimina spp. and Reophax fusiformis, which displayed maximal densities at the southernmost stations, concurrent with the highest Jz levels. The dominant species and vertical foraminiferal distributions responded to the different environmental conditions impacting the area (e.g. PP, grain size, nutrient content), which were most likely related to the hydrodynamic conditions. Hydrodynamic conditions cause differences in PP according to the locations of water masses and their fronts at the surface, according to the depth and current intensity; they determined energetic differences across the benthic environment, controlling organic matter sedimentation as well as grain size, which influenced oxygen availability within sediments.

  16. Saproxylic Beetle Assemblage Selection as Determining Factor of Species Distributional Patterns: Implications for Conservation.

    PubMed

    García-López, A; Galante, E; Micó, E

    2016-01-01

    The knowledge of the distributional patterns of saproxylic beetles is essential for conservation biology due to the relevance of this fauna in the maintenance of ecological processes and the endangerment of species. The complex community of saproxylic beetles is shaped by different assemblages that are composed of species linked by the microhabitats they use. We evaluate how different the species distribution patterns that are obtained can be, depending on the analyzed assemblage and to what extent these can affect conservation decisions. Beetles were sampled using hollow emergence and window traps in three protected areas of the Iberian Peninsula. Species richness, composition, and diversity turnover were analyzed for each sampling method and showed high variation depending on the analyzed assemblage. Beta diversity was clearly higher among forests for the assemblage captured using window traps. This method collects flying insects from different tree microhabitats and its captures are influenced by the forest structuring. Within forests, the assemblages captured by hollow emergence traps, which collect the fauna linked to tree hollows, showed the largest turnover of species, as they are influenced by the characteristics of each cavity. Moreover, the selection of the forest showing the highest species richness strongly depended on the studied assemblage. This study demonstrates that differences in the studied assemblages (group of species co-occurring in the same habitat) can also lead to significant differences in the identified patterns of species distribution and diversity turnover. This fact will be necessary to take into consideration when making decisions about conservation and management. PMID:27252483

  17. Statistical analysis of factors affecting landslide distribution in the new Madrid seismic zone, Tennessee and Kentucky

    USGS Publications Warehouse

    Jibson, R.W.; Keefer, D.K.

    1989-01-01

    More than 220 large landslides along the bluffs bordering the Mississippi alluvial plain between Cairo, Ill., and Memphis, Tenn., are analyzed by discriminant analysis and multiple linear regression to determine the relative effects of slope height and steepness, stratigraphic variation, slope aspect, and proximity to the hypocenters of the 1811-12 New Madrid, Mo., earthquakes on the distribution of these landslides. Three types of landslides are analyzed: (1) old, coherent slumps and block slides, which have eroded and revegetated features and no active analogs in the area; (2) old earth flows, which are also eroded and revegetated; and (3) young rotational slumps, which are present only along near-river bluffs, and which are the only young, active landslides in the area. Discriminant analysis shows that only one characteristic differs significantly between bluffs with and without young rotational slumps: failed bluffs tend to have sand and clay at their base, which may render them more susceptible to fluvial erosion. Bluffs having old coherent slides are significantly higher, steeper, and closer to the hypocenters of the 1811-12 earthquakes than bluffs without these slides. Bluffs having old earth flows are likewise higher and closer to the earthquake hypocenters. Multiple regression analysis indicates that the distribution of young rotational slumps is affected most strongly by slope steepness: about one-third of the variation in the distribution is explained by variations in slope steepness. The distribution of old coherent slides and earth flows is affected most strongly by slope height, but the proximity to the hypocenters of the 1811-12 earthquakes also significantly affects the distribution. The results of the statistical analyses indicate that the only recently active landsliding in the area is along actively eroding river banks, where rotational slumps formed as bluffs are undercut by the river. The analyses further indicate that the old coherent slides

  18. Distribution of fiber development genes and transcription factors between At and Dt subgenomes in tetraploid cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As the worlds leading natural material used in the manufacture of textiles, cotton fibers are important seed trichomes derived from individual cells of the epidermal layer of the seed coat. Cotton fiber development is determined by large numbers of genes and transcription factors. However, little ...

  19. Immunohistochemical distribution of early pregnancy factor in ovary, oviduct and placenta of pregnant gilts.

    PubMed

    Grosso, M C; Bellingeri, R V; Motta, C E; Alustiza, F E; Picco, N Y; Vivas, A B

    2015-01-01

    Early pregnancy factor (EPF) is an immunosuppressant that promotes maternal immune system tolerance of the allogenic fetus. Little is known about localization of this factor in different tissues and nothing has been reported about localization in swine reproductive and placental tissues. We determined the concentration of EPF in serum of gilts and porcine placenta conditioned medium (PPCM). We also analyzed the expression of EPF in different reproductive tissues of pregnant gilts at 10, 30, 60 and 90 days of pregnancy. EPF concentration in serum and PPCM was determined by western blot and densitometry. EPF expression in reproductive tissue was assessed by immunohistochemistry. The highest concentration of EPF was observed at 30 days in serum and PPCM; the concentration was higher in PPCM than in serum at the stages we evaluated. All reproductive tissues from the gestational stages analyzed showed specific labeling of EPF, but this labeling did not appear in non-pregnant gilts. At 30 days pregnancy, the EPF expression in the ovary was predominantly in follicular lutein cells, probably owing to its function as a luteotrophic factor. In the oviduct, EPF was expressed in unciliated secretory epithelial cells and in the cilia of ciliated cells. In the placenta, EPF was expressed in the fetal portion (mesoderm chorioallantois and epithelium of endoderm). EPF acts as an autocrine and paracrine growth factor for the trophoblast during the peri-implantation period. PMID:24989882

  20. 25 CFR Appendix C to Subpart C - Relative Need Distribution Factor

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... factor used to define a portion of transportation need based on the number of American Indian or Alaska Native people served. The population data used will be the American Indian and Alaska Native Service Population developed by the Department of Housing and Urban Development, under the Native American...

  1. Translationally invariant calculations of form factors, nucleon densities and momentum distributions for finite nuclei with short-range correlations included

    NASA Astrophysics Data System (ADS)

    Shebeko, A. V.; Grigorov, P. A.; Iurasov, V. S.

    2012-11-01

    Relying upon our previous treatment of the density matrices for nuclei (in general, nonrelativistic self-bound finite systems) we are studying a combined effect of center-of-mass motion and short-range nucleon-nucleon correlations on the nucleon density and momentum distributions in light nuclei (4He and 16O). Their intrinsic ground-state wave functions are constructed in the so-called fixed center-of-mass approximation, starting with mean-field Slater determinants modified by some correlator ( e.g., after Jastrow or Villars). We develop the formalism based upon the Cartesian or boson representation, in which the coordinate and momentum operators are linear combinations of the creation and annihilation operators for oscillatory quanta in the three different space directions, and get the own "Tassie-Barker" factors for each distribution and point out other model-independent results. After this separation of the center-of-mass motion effects we propose additional analytic means in order to simplify the subsequent calculations ( e.g., within the Jastrow approach or the unitary correlation operator method). The charge form factors, densities and momentum distributions of 4He and 16O evaluated by using the well-known cluster expansions are compared with data, our exact (numerical) results and microscopic calculations.

  2. Culicoides species composition and environmental factors influencing African horse sickness distribution at three sites in Namibia.

    PubMed

    Liebenberg, Danica; Piketh, Stuart; Labuschagne, Karien; Venter, Gert; Greyling, Telane; Mienie, Charlotte; de Waal, Tania; van Hamburg, Huib

    2016-11-01

    African horse sickness (AHS) is one of the most lethal infectious, non-contagious, vector-borne disease of equids. The causative agent, African horse sickness virus (AHSV) is transmitted via Culicoides midges (Diptera: Ceratopogonidae). AHS is endemic to Namibia but detailed studies of Culicoides communities and influencing environmental parameters are limited. This study aims to determine the Culicoides species composition at three different sites and to assess environmental parameters influencing the geographical distribution of AHS in Namibia. Weekly collections of Culicoides were made during the AHS peak season from January to May for 2013 and 2014 using the Onderstepoort 220V UV-light trap. Out of 397 collections made, 124 collections (3287 Culicoides) were analysed for AHSV presence with RT-qPCR. A total of 295 collections were analysed for total Culicoides (all collected Culicoides individuals) and in 75% of these collections the Culicoides were identified to species level. C. imicola was the dominant species with proportional representation of 29.9%. C. subschultzei, C. exspectator and C. ravus each contribute more than 10% to the species composition. The lowest number of Culicoides was collected at Aus 9980, a total of 21819 at Windhoek and the highest number at Okahandja 47343. AHSV was present at all three sites during 2013 but only in Windhoek and Okahandja during 2014. Multivariate analyses of data from the two year survey indicate the environmental parameters in order of importance for the distribution of AHS in Namibia as precipitation>temperature>clay>relative humidity>NDVI. The implication of these findings is that any precipitation event increases Culicoides numbers significantly. Together with these results the high number of species found of which little is known regarding their vector competence, add to the complexity of the distribution of AHS in Namibia. PMID:27491343

  3. Stress distributions and stress intensity factors in ceramic roller bearing rings

    NASA Astrophysics Data System (ADS)

    Müller, W. H.

    1995-06-01

    A method is presented which allows to compute the stress intensity factors (SIFs) of a ceramic roller bearing ring with a surface flaw. First, the stresses due to mechanical loads applied to the surfaces of the undamaged ring are computed, using Michell's expression for Airy's stress function in polar coordinates ([l]). Second, the stress intensity factors of the flaw are obtained using Tada's additivity principle ([2]), namely by integration of the point force solution for the SIF of a surface crack with the aforementioned stresses as input parameter. To illustrate the procedure, the special case of a ring with a surface flaw which is loaded by six equidistantly spaced cylindrical rollers will be studied numerically.

  4. [Relationship Between the Phytoplankton Distribution and Environmental Factors in Fenhe Scenic Spot of Taiyuan].

    PubMed

    Feng, Jia; Guo, Yu-ning; Wang, Fei; Lü, Jun-ping; Liu, Qi; Xie, Shu-lian; Cheng, Ge; Zhang Jian-min

    2016-04-15

    In order to explore the structural characteristics of phytoplankton community and the water quality and the water quality of the Fenhe scenic spot in Taiyuan, the species composition and the biomass of phytoplankton as well as their correlation with the environmental factors were monitored. The survey selected 9 sampling sites along the up and lower reaches in Fenhe scenic spot of Taiyuan, from Chaicun Bridge to Xiangyun Bridge. During the wet season (June-Octoher) in 2014, specimens were collected, qualitative and quantitative investigation on the algae and monitoring on physicochemical indexes of the water were studied. Meanwhile, the water quality was analyzed and evaluated combining all the physicochemical indexes and cell density. Correlation analysis and RDA were conducted to analyze the relationship of algal community structure and the environmental factors. The main results showed that the dominant phytoplanktons were Cyanophyta, Chlorophyta and Bacillariophyta. The algal biomass first increased and then reduced during the wet season, and the maximum value of hiomass occurred in July. There were many differences among different sampling points. The cell densities of phytoplankton were much higher in three central areas than the other sampling sites. Physical and chemical factors showed a variation tendency in time and space. Based on the results of RDA hetween phytoplankton cell densities and the physic-chemical parameters, the cell densities and the physic..chemical parameters had different correlations. The total cell density had significant positive correlation with dissolved oxygen, and negative correlation with COD. There were extremely significant positive correlations between diatom cell densities and water temperature, air temperature. But the diatom cell density was obviously negatively correlated with COD. It was distinct that the functions of the environment factors were different in temporal and spatial distrihution. The state index of

  5. The penC mutation conferring antibiotic resistance in Neisseria gonorrhoeae arises from a mutation in the PilQ secretin that interferes with multimer stability

    PubMed Central

    Zhao, Shuqing; Tobiason, Deborah M.; Hu, Mei; Seifert, H. Steven; Nicholas, Robert A.

    2008-01-01

    The penC resistance gene was previously characterized in a FA19 penA mtrR penB gonococcal strain (PR100) as a spontaneous mutation that increased resistance to penicillin and tetracycline. We show here that antibiotic resistance mediated by penC is the result of a Glu-666 to Lys missense mutation in the pilQ gene that interferes with the formation of the SDS-resistant high-molecular-mass PilQ secretin complex, disrupts piliation, and decreases transformation frequency by 50-fold. Deletion of pilQ in PR100 confers the same level of antibiotic resistance as the penC mutation, but increased resistance was observed only in strains containing the mtrR and penB resistance determinants. Site-saturation mutagenesis of Glu-666 revealed that only acidic or amidated amino acids at this position preserved PilQ function. Consistent with early studies suggesting the importance of cysteine residues on stability of the PilQ multimer, mutation of either of the two cysteine residues in FA19 PilQ led to a similar phenotype as penC: increased antibiotic resistance, loss of piliation, intermediate levels of transformation competence, and absence of SDS-resistant PilQ oligomers. These data show that a functional secretin complex can enhance the entry of antibiotics into the cell and suggest that the PilQ oligomer forms a pore in the outer membrane through which antibiotics diffuse into the periplasm. PMID:16101998

  6. Hamilton study: distribution of factors confounding the relationship between air quality and respiratory health

    SciTech Connect

    Pengelly, L.D.; Kerigan, A.T.; Goldsmith, C.H.; Inman, E.M.

    1984-10-01

    Hamilton, Ontario is an industrial city with a population of 300,000 which is situated at the western end of Lake Ontario. Canada's two largest iron and steel mills are located here; the city historically has had relatively poor air quality, which has improved markedly in the last 25 years. Concern about the health effects of current air quality recently led us to carry out an epidemiological study of the effects of air pollution on the respiratory health of over 3500 school children. Respiratory health was measured by pulmonary function testing of each child, and by an assessment of each child's respiratory symptoms via a questionnaire administered to the parents. Previous studies had shown that other environmental factors (e.g. parental smoking, parental cough, socioeconomic level, housing, and gas cooking) might also affect respiratory health, and thus confound any potential relationships between health and air pollution. The questionnaire also collected information on many of these confounding factors. For the purposes of initial analysis, the city was divided into five areas in which differences in air quality were expected. In general, factors which have been associated with poor respiratory health were observed to be more prevalent in areas of poorer air quality.

  7. Distribution of Gamma-ray Burst Ejecta Energy with Lorentz Factor

    SciTech Connect

    Granot, Jonathan; Kumar, Pawan; /Texas U., Astron. Dept.

    2005-10-07

    The early X-ray afterglow for a significant number of gamma-ray bursts detected by the Swift satellite is observed to have a phase of very slow flux decline with time (F{sub {nu}} {proportional_to} t{sup -{alpha}} with 0.2 {approx}< {alpha} {approx}< 0.8) for 10{sup 2.5} s{approx}< t {approx}< 10{sup 4} s, while the subsequent decline is the usual 1 {approx}< {alpha}{sub 3} {approx}< 1.5 behavior, that was seen in the pre-Swift era. We show that this behavior is a natural consequence of a small spread in the Lorentz factor of the ejecta, by a factor of {approx} 2-4, where the slower ejecta gradually catch-up with the shocked external medium, thus increasing the energy of forward shock and delaying its deceleration. The end of the ''shallow'' flux decay stage marks the beginning of the Blandford-McKee self similar external shock evolution. This suggests that most of the energy in the relativistic outflow is in material with a Lorentz factor of {approx} 30-50.

  8. Updated greenhouse gas and criteria air pollutant emission factors and their probability distribution functions for electricity generating units

    SciTech Connect

    Cai, H.; Wang, M.; Elgowainy, A.; Han, J.

    2012-07-06

    Greenhouse gas (CO{sub 2}, CH{sub 4} and N{sub 2}O, hereinafter GHG) and criteria air pollutant (CO, NO{sub x}, VOC, PM{sub 10}, PM{sub 2.5} and SO{sub x}, hereinafter CAP) emission factors for various types of power plants burning various fuels with different technologies are important upstream parameters for estimating life-cycle emissions associated with alternative vehicle/fuel systems in the transportation sector, especially electric vehicles. The emission factors are typically expressed in grams of GHG or CAP per kWh of electricity generated by a specific power generation technology. This document describes our approach for updating and expanding GHG and CAP emission factors in the GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model developed at Argonne National Laboratory (see Wang 1999 and the GREET website at http://greet.es.anl.gov/main) for various power generation technologies. These GHG and CAP emissions are used to estimate the impact of electricity use by stationary and transportation applications on their fuel-cycle emissions. The electricity generation mixes and the fuel shares attributable to various combustion technologies at the national, regional and state levels are also updated in this document. The energy conversion efficiencies of electric generating units (EGUs) by fuel type and combustion technology are calculated on the basis of the lower heating values of each fuel, to be consistent with the basis used in GREET for transportation fuels. On the basis of the updated GHG and CAP emission factors and energy efficiencies of EGUs, the probability distribution functions (PDFs), which are functions that describe the relative likelihood for the emission factors and energy efficiencies as random variables to take on a given value by the integral of their own probability distributions, are updated using best-fit statistical curves to characterize the uncertainties associated with GHG and CAP emissions in life

  9. [Spatial-temporal distributions of dissolved inorganic carbon and its affecting factors in the Yellow River estuary].

    PubMed

    Guo, Xing-Sen; Lü, Ying-Chun; Sun, Zhi-Gao; Wang, Chuan-Yuan; Zhao, Quan-Sheng

    2015-02-01

    Estuary is an important area contributing to the global carbon cycle. In order to analyze the spatial-temporal distribution characteristics of the dissolved inorganic carbon (DIC) in the surface water of Yellow River estuary. Samples were collected in spring, summer, fall, winter of 2013, and discussed the correlation between the content of DIC and environmental factors. The results show that, the DIC concentration of the surface water in Yellow River estuary is in a range of 26.34-39.43 mg x L(-1), and the DIC concentration in freshwater side is higher than that in the sea side. In some areas where the salinity is less than 15 per thousand, the DIC concentration appears significant losses-the maximum loss is 20.46%. Seasonal distribution of performance in descending order is spring, fall, winter, summer. Through principal component analysis, it shows that water temperature, suspended solids, salinity and chlorophyll a are the main factors affecting the variation of the DIC concentration in surface water, their contribution rate is as high as 83% , and alkalinity, pH, dissolved organic carbon, dissolved oxygen and other factors can not be ignored. The loss of DIC in the low area is due to the calcium carbonate sedimentation. DIC presents a gradually increasing trend, which is mainly due to the effects of water retention time, temperature, outside input and environmental conditions. PMID:26031070

  10. Benthic invertebrate distributions in the San Joaquin River, California, in relation to physical and chemical factors

    USGS Publications Warehouse

    Leland, H.V.; Fend, S.V.

    1998-01-01

    The invertebrate fauna of nontidal portions of the lower San Joaquin River and its major tributaries is described in relation to water quality and habitat using canonical correspondence analysis, autecological metrics, and indicator species analysis. A large-scale (basin-wide) pattern in community response to salinity (sulfate-bicarbonate type) was detected when standardized, stable substratum was sampled. Community structure, taxa richness, and EPT (ephemeropterans, plecopterans, and trichopterans) richness varied with dissolved solids concentration (55-1700 mg total dissolved solids. L-1), and distributions of many taxa indicated salinity optima. Distinct assemblages associated with either high or low salinity were evident over this range. Large-scale patterns in community structure were unrelated to pesticide distributions. Structure and taxa richness of invertebrate assemblages in sand substratum varied both with salinity and with microhabitat heterogeneity. The benthic fauna generally was dominated by a taxa-poor assemblage of specialized psammophilous species, contributing to a weaker relationship between community structure and water quality than was observed using standardized substratum. Habitat types and associated dominant species were characterized using indicator species analysis. Species assemblages did not vary substantially with irrigation regime or fiver discharge, indicating that structure of invertebrate communities was a conservative measure of water quality.

  11. Heavy metal distribution and controlling factors within coastal plain sediments, Bells Creek catchment, southeast Queensland, Australia.

    PubMed

    Liaghati, Tania; Preda, Micaela; Cox, Malcolm

    2004-01-01

    Bells Creek catchment in southeast Queensland (Australia) is a non-industrialised coastal plain limited to small settlements and agricultural land. A study was initiated to examine elevated metal concentrations and to assess horizontal and vertical distribution of those elements. Ninety-nine samples were analysed for Cr, V, Ni, Cu, Zn, Pb, As, Fe, Mn and Al. Total organic carbon, sulfur content and mineralogy of samples along with land-use practices across the catchment were used to identify processes which influence metal distribution. A comparison between metal concentration within the study area and mean heavy metal content of standard sandstone showed that except for Mn, all other metals showed elevated levels throughout the catchment. When metal concentrations were compared to parent bedrock, however, it was concluded that elevated levels are likely to be natural. A normalisation procedure was applied to the data set and this analysis validated that elevated trace metal concentrations in most samples are not due to artificial contamination. While surficial estuarine sediments were only enriched in V, soils were dominantly enriched in Cr, Zn and V. Overall, geochemistry and mineralogy of the samples show the effect of both natural and anthropogenic inputs to the catchment, however, natural processes are more dominant than anthropogenic inputs in concentrating metals. PMID:14592571

  12. Calculation of spatial distribution of optical escape factor and its application to He I collisional-radiative model

    SciTech Connect

    Iida, Yohei; Kado, Shinichiro; Tanaka, Satoru

    2010-12-15

    An integral analytical formula for a spatial distribution of the optical escape factor (OEF) in an infinite cylindrical plasma is derived as a function of an arbitrary upper state spatial density profile, the temperature ratio of the upper state to the lower state, and the optical depth of the corresponding transition. Test calculations are carried out for three different upper state profiles, i.e., uniform (rectangular), parabolic, and Gaussian upper state profiles. The OEF takes on negative values at the periphery of the parabolic and Gaussian upper state profiles. These characteristics cannot be expressed by the conventional OEF formulas derived for the center of the plasma, even though the optical depth is increased. In addition to the analytical derivation of the formula, two practical formulas are proposed: an empirical formula of the spatial distribution of the OEF for the Gaussian upper state density profile and a linear formula of the OEF distribution for upper state profiles that are expressed as linear combinations. These formulas enable us to calculate the spatial distribution of the OEF for the multiple-Gaussian upper state profile without the need for time-consuming integral calculations.

  13. The Impact of Climatic Risk Factors on the Prevalence, Distribution, and Severity of Acute and Chronic Trachoma

    PubMed Central

    Ramesh, Anita; Kovats, Sari; Haslam, Dominic; Schmidt, Elena; Gilbert, Clare E.

    2013-01-01

    Background and Objectives Trachoma is the most common cause of infectious blindness. Hot, dry climates, dust and water scarcity are thought to be associated with the distribution of trachoma but the evidence is unclear. The aim of this study was to evaluate the epidemiological evidence regarding the extent to which climatic factors explain the current prevalence, distribution, and severity of acute and chronic trachoma. Understanding the present relationship between climate and trachoma could help inform current and future disease elimination. Methods A systematic review of peer-reviewed literature was conducted to identify observational studies which quantified an association between climate factors and acute or chronic trachoma and which met the inclusion and exclusion criteria. Studies that assessed the association between climate types and trachoma prevalence were also reviewed. Results Only eight of the 1751 papers retrieved met the inclusion criteria, all undertaken in Africa. Several papers reported an association between trachoma prevalence and altitude in highly endemic areas, providing some evidence of a role for temperature in the transmission of acute disease. A robust mapping study found strong evidence of an association between low rainfall and active trachoma. There is also consistent but weak evidence that the prevalence of trachoma is higher in savannah-type ecological zones. There were no studies on the effect of climate in low endemic areas, nor on the effect of dust on trachoma. Conclusion Current evidence on the potential role of climate on trachoma distribution is limited, despite a wealth of anecdotal evidence. Temperature and rainfall appear to play a role in the transmission of acute trachoma, possibly mediated through reduced activity of flies at lower temperatures. Further research is needed on climate and other environmental and behavioural factors, particularly in arid and savannah areas. Many studies did not adequately control for

  14. Distribution and Risk Factors of Disability Attributed to Personality Disorders: A National Cross-sectional Survey in China

    PubMed Central

    Zhang, Ting-Ting; Huang, Yue-Qin; Liu, Zhao-Rui; Chen, Hong-Guang

    2016-01-01

    Background: Personality disorders can lead to some disability. However, little is known about the disability prevalence and function impairments. This study aimed to describe the disability prevalence attributed to personality disorders, its distribution, impairments of daily activities and social functions, and risk factors in China. Methods: Using a descriptive and analytic epidemiological method, data from the Second China National Sample Survey on Disability in 2006 were analyzed. The disability prevalence attributed to personality disorders, its distribution in different people and regions, and risk factors were statistically calculated. Results: Respondents included 1,909,205 adults. The disability prevalence rate attributed to personality disorders in China was 5.9/100,000. The disability rate attributed to personality disorders of males was higher than that of females (P = 0.012), while the rate of the unemployed was higher than that of the employed (P < 0.001). Furthermore, the rates of unmarried/divorced/widowed people and the illiterate population were higher than those of married and educated people (P < 0.001). Regarding the severity of disability attributable to personality disorders, mild disability accounted for a majority or 60% of the respondents. The data showed that disability mainly impaired respondents’ ability to engage in daily activities, get along with people, and participate in social situations. According to the case-control study, marriage, employment, and higher education were protective factors of disability. Conclusions: The prevalence of disability attributed to personality disorders is low in China and always leads to mild disability. The distribution of disability attributed to personality disorders also varies in the Chinese population. PMID:27453222

  15. Risk Factors for Contamination of Hotel Water Distribution Systems by Legionella Species▿

    PubMed Central

    Mouchtouri, Varvara; Velonakis, Emmanuel; Tsakalof, Andreas; Kapoula, Christina; Goutziana, Georgia; Vatopoulos, Alkiviadis; Kremastinou, Jenny; Hadjichristodoulou, Christos

    2007-01-01

    The Legionella colonization frequency at 385 Greek hotel hot and cold water distribution systems was 20.8%. Legionella contamination was associated with the presence of an oil heater (odds ratio [OR] = 2.04, 95% confidence interval [CI] = 1.12 to 3.70), with the sample temperature (OR = 0.26, 95% CI = 0.1 to 0.5), with seasonal operation (OR = 3.23, 95% CI = 1.52 to 6.87), and with the presence of an independent disinfection system (OR = 0.30, 95% CI = 0.15 to 0.62). The same water temperatures, free-chlorine levels, and pHs differently affect the survival of various Legionella spp. PMID:17261527

  16. [Distribution of proteins in neural membranes as a factor of reabsorption of endoneural (interstitial) fluid].

    PubMed

    Banin, V V; Gasymov, E K

    1990-09-01

    An investigation on distribution of horseradish peroxidase (HP) product in the sciatic nerve membranes of albino rats, after HP intravenous injection, has been performed. Getting into the interstitial space of epineurium across the microvessel walls, HP spreads as far as the internal layer of the perineural membrane, forming a distinct gradient of concentration of protein at its border. In 60 min after injection of the tracer the value of the perineural-endoneural gradient for proteins is about 70-80% of the value of the plasma-endoneural gradient. A possible mechanism of the endoneural fluid evacuation, connected with various values of protein concentration in the endoneural space and within the nerve perineural membrane is discussed. PMID:2275614

  17. Snow Dunes: A Controlling Factor of Melt Pond Distribution on Arctic Sea Ice

    NASA Technical Reports Server (NTRS)

    Petrich, Chris; Eicken, Hajo; Polashenski, Christopher M.; Sturm, Matthew; Harbeck, Jeremy P.; Perovich, Donald K.; Finnegan, David C.

    2012-01-01

    The location of snow dunes over the course of the ice-growth season 2007/08 was mapped on level landfast first-year sea ice near Barrow, Alaska. Landfast ice formed in mid-December and exhibited essentially homogeneous snow depths of 4-6 cm in mid-January; by early February distinct snow dunes were observed. Despite additional snowfall and wind redistribution throughout the season, the location of the dunes was fixed by March, and these locations were highly correlated with the distribution of meltwater ponds at the beginning of June. Our observations, including ground-based light detection and ranging system (lidar) measurements, show that melt ponds initially form in the interstices between snow dunes, and that the outline of the melt ponds is controlled by snow depth contours. The resulting preferential surface ablation of ponded ice creates the surface topography that later determines the melt pond evolution.

  18. Factors Affecting the Evolution of Hurricane Erin and the Distributions of Hydrometeors: Role of Microphysical Processes

    NASA Technical Reports Server (NTRS)

    McFarquhar, Greg M.; Zhang, Henian; Dudhia, Jimy; Halverson, Jeffrey B.; Heymsfield, Gerald; Hood, Robbie; Marks, Frank, Jr.

    2003-01-01

    Fine-resolution simulations of Hurricane Erin 2001 are conducted using the Penn State University/National Center for Atmospheric Research mesoscale model version 3.5 to investigate the role of thermodynamic, boundary layer and microphysical processes in Erin's growth and maintenance, and their effects on the horizontal and vertical distributions of hydrometeors. Through comparison against radar, radiometer, and dropsonde data collected during the Convection and Moisture Experiment 4, it is seen that realistic simulations of Erin are obtained provided that fine resolution simulations with detailed representations of physical processes are conducted. The principle findings of the study are as follows: 1) a new iterative condensation scheme, which limits the unphysical increase of equivalent potential temperature associated with most condensation schemes, increases the horizontal size of the hurricane, decreases its maximum rainfall rate, reduces its intensity, and makes its eye more moist; 2) in general, microphysical parameterization schemes with more categories of hydrometeors produce more intense hurricanes, larger hydrometeor mixing ratios, and more intense updrafts and downdrafts; 3) the choice of coefficients describing hydrometeor fall velocities has as big of an impact on the hurricane simulations as does choice of microphysical parameterization scheme with no clear relationship between fall velocity and hurricane intensity; and 4) in order for a tropical cyclone to adequately intensify, an advanced boundary layer scheme (e.g., Burk-Thompson scheme) must be used to represent boundary layer processes. The impacts of varying simulations on the horizontal and vertical distributions of different categories of hydrometeor species, on equivalent potential temperature, and on storm updrafts and downdrafts are examined to determine how the release of latent heat feedbacks upon the structure of Erin. In general, all simulations tend to overpredict precipitation rate

  19. [Factors limiting distribution of the rare lichen species Lobaria pulmonaria (in forests of the Kologriv Forest Nature Reserve)].

    PubMed

    Ivanova, N V

    2015-01-01

    The distribution patterns and coenotic confines ofthe epiphytic lichen Lobaria pulmonaria have been studied. The factors limiting the habitat of this rare lichen species in the Kologriv Forest Nature Reserve (southern taiga subzone) have been revealed. It has been shown that L. pulmonaria is attracted to forest areas, which are less affected by humans and characterized by better light conditions than other communities. It has been found that L. pulmonaria is able to colonize trees at various ontogenetic states, beginning from virginal ones. PMID:26021161

  20. Controlling factors on productivity and size abundance distribution of phytoplankton in Patagonian fjords

    NASA Astrophysics Data System (ADS)

    Cuevas, L. A.; Iriarte, J. L.; Gonzalez, H.; Silva, N.; Vargas, C.

    2012-12-01

    Temperature and resource availability has been suggested to play an important role controlling phytoplankton size structure and productivity. Here we used five independent research cruisers covering the entire Patagonian fjords (41.5-56.0 degress latitude South) to conduct a comparative analysis between zones and to determine the importance of the controlling factors. For the entire Patagonian area phytoplankton size structure seems independent from temperature, but varies with total phytoplankton biomass and productivity. Microphytoplankton contribute with more than 80% in high productivity waters (chlorophyll-a higher than 5 μg L-1) and picophytoplankton dominates when chlorophyll-a is lower than 1 μg L-1. In addition, NO3:Si(OH)4 ratio control phytoplankton size structure, where a large decrease in Si(OH)4 from north to south Patagonia (from 20 to 0.1 mM average, respectively) seems to be a major factor of control. Major and prolonged effects expected in fjord areas, such as anthropogenic eutrophication and global warning, may modify the observed relationships leading to important changes in the phytoplankton community and its ecological role.

  1. Seasonal habitat suitability modeling and factors affecting the distribution of Asian Houbara in East Iran.

    PubMed

    Haghania, Ali; Aliabadian, Mansour; Sarhangzadeh, Jalil; Setoodehc, Ahad

    2016-08-01

    In this study, maximum entropy models were developed in four seasons to evaluate habitat suitability and factors affecting Asian Houbara in Iran. Environmental variables used in modeling consisted of 42 environmental and climate variables for Nayband wildlife refuge and 36 environmental and climate variables for Petregan protected area. Also, seasonal overlap area were obtained using the ENM TOOLS software. The results showed that the most important factors affecting habitat suitability of the Asian Houbara in all seasons included the ratio of distance to hill, the type of Artemisia-Gymnocarpus, distance to the slope (8-12%) in the Nayband wildlife refuge, distance to the type of Artemisia aucheri, distance to the Land Passion, and distance to the dry land farming in the Petregan region. In summer, the most suitable habitat is Nayband but is Petergan during fall-winter. there is maximum overlap in summer, and the least overlap in the spring these areas. The results of this study can be used as a valuable tool in implementing conservation and management strategies, in order to increase desirable habitats in the eastern part of Iran. PMID:27570839

  2. Altered (/sup 125/I)epidermal growth factor binding and receptor distribution in psoriasis

    SciTech Connect

    Nanney, L.B.; Stoscheck, C.M.; Magid, M.; King, L.E. Jr.

    1986-03-01

    Stimulation of growth and differentiation of human epidermis by epidermal growth factor (EGF) is mediated by its binding to specific receptors. Whether EGF receptors primarily mediate cell division or differentiation in hyperproliferative disease such as psoriasis vulgaris is unclear. To study the pathogenesis of psoriasis, 4-mm2 punch biopsy specimens of normal, uninvolved, and involved psoriatic skin were assayed for EGF receptors by autoradiographic, immunohistochemical, and biochemical methods. Using autoradiographic and immunohistochemical methods, basal keratinocytes were found to contain the greatest number of EGF binding sites and immunoreactive receptors as compared to the upper layers of the epidermis in both normal epidermis and psoriatic skin. No EGF receptor differences between normal and psoriatic epidermis were observed in this layer. In the upper layers of the epidermis, a 2-fold increase in EGF binding capacity was observed in psoriatic skin as compared with normal thin or thick skin. Biochemical methods indicated that (/sup 125/I)EGF binding was increased in psoriatic epidermis as compared with similar thickness normal epidermis when measured on a protein basis. Epidermal growth factor was shown to increase phosphorylation of the EGF receptor in skin. EGF receptors retained in the nonmitotic stratum spinosum and parakeratotic stratum corneum may reflect the incomplete, abnormal differentiation that occurs in active psoriatic lesions. Alternatively, retained EGF receptors may play a direct role in inhibiting cellular differentiation in the suprabasal layers.

  3. Defective von willebrand factor activity detected by the filterometer in three clinical conditions.

    PubMed

    O'Brien, J R; Tsai, H M; Etherington, M D

    2000-11-01

    When exposed to high levels of shear in a filterometer, platelets bind to von Willebrand factor (vWF) via receptors Ib and IIb/IIIa, forming aggregates that block the filteromer. In this study we used the filterometer to explore the mechanisms by which abnormal vWF-platelet interaction might occur. In the first phase of the study, the global vWF-platelet interaction in native blood was investigated. In the second phase, to eliminate the difference that platelets might contribute, samples of platelet-poor plasma from test individuals were added to normal control blood and the mixtures were investigated by the filterometer. The filterometer results were adjusted for the antigen concentrations to obtain vWF potency ratios. Sodium dodecyl sulphate (SDS) agarose gel electrophoresis and SDS-Polyacylamide gel electrophoresis (PAGE) were used to analyze multimeric size and proteolytic profiles of vWF. Pregnancy was associated with high platelet retention, high vWF antigen concentration, normal multimeric size distribution, but decreased vWF potency ratios. The plasma samples of pregnancy contained one 183-kDa fragment not detected in normal plasma. These results suggested that in pregnancy, platelets were highly active. However, presumably due to abnormal proteolytic cleavage, vWF potency was decreased. This decrease in vWF potency might minimize the risk of thrombosis in association with highly active platelets. Renal transplant patients had normal platelet retention but high vWF levels. The plasma vWF contained normal multimers. A decrease in vWF potency, presumably caused by toxic inhibitors in the plasma, was detected. Aortic valve stenosis patients had decreased platelet retention, normal or slightly increased vWF antigen concentration and a decrease in large multimers. As a result, the vWF potency was markedly decreased. However, the results obtained with the filterometer became normal when the studies were repeated 3 months postpartum, when renal function had

  4. Assessment of factors related to heavy metals distribution in abandoned mining soils in Madrid, central Spain

    NASA Astrophysics Data System (ADS)

    Torres, Manuel; Carral, Pilar; Alvarez, Ana M.; Hernández, Zulimar; Lorena, Recio-Vázquez; Marques, Maria J.; Almendros, Gonzalo

    2013-04-01

    Exploitation of metallic mineral deposits and its subsequent abandonment in last decades has lead to significant environmental hazard for natural systems. The present study concerns the distribution and mobility of heavy metals and trace elements mainly As, Cu, Cd, Co, Mn and V, in sulphide-rich soils. The site studied (Sierra de Guadarrama, Garganta de los Montes, Madrid) is at 1200 m asl. Soils are Humic and Dystric Cambisols (WRB) developed on gneisses; the main minerals consist of sulphides and include chalcopyrite, pyrite, marcasite, galena and arsenopyrite. Concentration data of the different species of heavy metals as dependent variables in addition to a series of independent variables mainly soil organic matter were subjected to multivariate chemometric treatments including multidimensional scaling (MDS), principal component analysis (PCA) and support vector machine (SVM) for a preliminary survey on the possible role of soil organic matter in the distribution and speciation of heavy metals in soils. The soil heavy metals speciation was determined using the BCR (Community Bureau of Reference, European Commission) sequential extraction procedure and analysed by ICP-MS. The total contents of these elements were calculated as the sum of the four BCR fractions. The results showed element concentrations decreasing with the distance from the source of pollution. The highest amounts of As and Mn, and Cu, Cd, Co and V were found at 10 and 100 m respectively. These values exceed the allowed limits of the environmental regulation. The percentages of extractable elements (step one of BCR) in relation to total elements show that Cu and Cd were significantly more easily extractable than the other elements. Metal availability in soils was generally controlled by total metal concentration. Data processing techniques coincided in pointing out the association of high levels of organic matter with the concentrations of elements extracted just in the most available forms: i

  5. Possible dietary protective factors in relation to the distribution of duodenal ulcer in India and Bangladesh.

    PubMed Central

    Jayaraj, A P; Tovey, F I; Clark, C G

    1980-01-01

    In India there are regions of high incidence and regions of low incidence of duodenal ulcer. Rats prefed for two weeks on diets from low incidence areas developed significantly fewer rumenal ulcers after pyloric ligation than rats fed on diets from high incidence areas. The protective action was found in various individual items of food taken from the diets of low incidence areas. Unrefined wheat and rice, certain pulses (black gram, green gram, horse gram), some millets (sava, kutki, ragi), soya bean, ladies' fingers, cabbage, spinach, and whole cream milk were protective. Refined wheat, polished rice, maize, cornflour, sorghum vulgare, sugar, bananas, amaranthus, brinjal, peanut oil, some pulses (Bengal gram, turdhal), and skimmed milk were non-protective. The protective factor seems to be either a lipid or a liposoluble substance which is active whether given orally or parenterally. Horse gram (Dolichos biflorus) is a particularly potent source. PMID:7461465

  6. Novel aspects of blood coagulation factor XIII. I. Structure, distribution, activation, and function

    SciTech Connect

    Muszbek, L.; Adany, R.; Mikkola, H.

    1996-10-01

    Blood coagulation factor XIII (FXIII) is a protransglutaminase that becomes activated by the concerted action of thrombin and Ca{sup 2+} in the final stage of the clotting cascade. In addition to plasma, FXIII also occurs in platelets, monocytes, and monocyte-derived macrophages. While the plasma factor is a heterotetramer consisting of paired A and B subunits (A{sub 2}B{sub 2}), its cellular counterpart lacks the B subunits and is a homodimer of potentially active A subunits (A{sub 2}). The gene coding for the A and B subunits has been localized to chromosomes 6p24-25 and 1q31-32.1, respectively. The genomic as well as the primary protein structure of both subunits has been established. Plasma FXIII circulates in association with its substrate precursor, fibrinogen. Fibrin(ogen) has an important regulatory role in the activation of plasma FXIII, for instance the proteolytic removal of activation peptide by thrombin, the dissociation of subunits A and B, and the exposure of the originally buried active site on the free A subunits. The end result of this process is the formation of an active transglutaminase, which crosslinks peptide chains through {epsilon}({gamma}-glutamyl)lysyl isopeptide bonds. The protein substrates of activated FXIII include components of the clotting-fibrinolytic system, adhesive and contractile proteins. The main physiological function of plasma FXIII is to cross-link fibrin and protect it from the fibrinolytic enzyme plasmin. The latter effect is achieved mainly by covalently linking {alpha}{sub 2} antiplasmin, the most potent physiological inhibitor of plasmin, to fibrin. Plasma FXIII seems to be involved in wound healing and tissue repair, and it is essential to maintaining pregnancy. Cellular FXIII, if exposed to the surface of the cells, might support or perhaps take over the hemostatic functions of plasma FXIII; however, its intracellular role has remained mostly unexplored. 328 refs., 4 figs.

  7. Driving Factors of Carbon Distribution in Soils as Determined by z*

    NASA Astrophysics Data System (ADS)

    Mnich, M.; Lawrence, C. R.; Harden, J. W.; Treat, C. C.; Schulz, M. S.

    2015-12-01

    Terrestrial soils store approximately three times the amount of carbon(C) stored in the atmosphere. Understanding the mechanisms resulting in soil organic carbon stabilization is necessary for predicting the fate of this carbon and potential feedbacks to climate change. Here, we explore how soil carbon depth gradients are influenced by factors such as age, parent material, mean annual temperature (MAT) and a modeled moisture/leaching index (LI). Specifically, we calculate a quantitative metric reflecting the depth gradient of organic carbon, z*, described by Rosenbloom et al. 2006, which describes the depth attenuation of C turnover by fitting the %C by depth relationship with an exponential decay function. We compare z* across several soil chronosequences (n=33) spanning a broad array of ecosystems and climates. The compiled chronosequence data were collected from previously published studies and ongoing USGS work. Each sequence consisted of at least two soils spanning a developmental age gradient and each soil included depth resolved carbon concentrations, with at least four different depths sampled in vertical profile. When the soil profile data were integrated across all depths, we found only weak relationships between total C in these profiles with various soil forming factors. Comparing depth resolved concentrations provided an opportunity to determine the significance of depth resolved gradients and particularly the importance of deep soil C. We found a significant positive relationship between z* and age, (R2=0.57, p=4.0*10-13), a significant negative relationship between z* and LI (R2=0.02, p=0.02), a significant relationship between (age x LI) and z* (R2=0.02, p=0.02, a positive relationship between z* and MAT (R2=0.1 p=0.01), and no relationship between z* and general parent material type (felsic, mafic, calcareous ; R2=0.04, p=0.01). These findings aid in determining the drivers of soil carbon storage across sites.

  8. Factors Affecting the Distribution of Wild Rice (Zizania palustris) and the Surrounding Macrophyte Community.

    NASA Astrophysics Data System (ADS)

    Pillsbury, R. W.; McGuire, M.

    2005-05-01

    A recent decline in wild rice wetlands is cause for concern due to its importance as a food source, refuge for wildlife, and cultural significance. Sixty wetlands in Wisconsin and Minnesota (USA) were sampled, with approximately equal numbers displaying dense, moderate and sparse wild rice production. Chemical, physical, and watershed parameters were measured as well as macrophyte densities. Data were analyzed using multivariate statistics (CCA). Moderate levels of phosphorus appear beneficial to the overall success of wild rice, while free-floating macrophytes show an overwhelming positive response to higher levels of P. The distribution of macrophytes bordering wild rice beds is correlated to pH,with Potamogeton robbinsii and filamentous green algae responding most strongly to its increase. Healthy stands of wild rice exhibit a narrow circum-neutral range of pH (6.1-8.0)which is significantly different from the greater range exhibited by sparse wild rice wetlands (6.5-8.5). This pattern was paralleled when considering depth which suggests that deeper wetlands may be more susceptible to wild rice loss. Management of existing wild rice wetlands should focus monitoring on pH, depth, phosphorus concentrations and shore development. We are currently using this data base to locate the best reintroduction sites for wild rice.

  9. Distribution of epidermal growth factor binding sites in the adult rat anterior pituitary gland

    SciTech Connect

    Chabot, J.G.; Walker, P.; Pelletier, G.

    1986-01-01

    The distribution of epidermal growth (EGF) binding sites was studied in the pituitary gland using light and electron microscope autoradiography which was performed at different time intervals (2 to 60 min) after intravenous (IV) injection of (/sup 125/I)EGF into adult rats. At the light microscopic level, the labeling was found over cells of the anterior pituitary gland. The time-course study performed by light microscope autoradiography showed that the maximal values were reached at the 2 min time interval. At this time interval, most silver grains were found at the periphery of the target cells. After, the number of silver grains decreased progressively and the localization of silver grains in the cytoplasm indicated the internalization of (/sup 125/I)EGF. Electron microscope autoradiography showed that labeling was mostly restricted to mammotrophs and somatotrophs. Control experiments indicated that the autoradiographic labeling was due specific interaction of (/sup 125/I)EGF with its binding site. These results indicate that EGF binding sites are present in at least two anterior pituitary cell types and suggest that EGF can exert a physiological role in the pituitary gland.

  10. Factors influencing the spatial distribution of Anopheles larvae in Coimbatore District, Tamil Nadu, India.

    PubMed

    Arjunan, Naresh Kumar; Kadarkarai, Murugan; Kumar, Shobana; Pari, Madhiyazhagan; Thiyagarajan, Nataraj; Vincent, C Thomas; Barnard, Donald R

    2015-12-01

    Malaria causes extensive morbidity and mortality in humans and results in significant economic losses in India. The distribution of immature malaria-transmitting Anopheles mosquitoes was studied in 17 villages in Coimbatore District as a prelude to the development and implementation of vector control strategies that are intended to reduce the risk of human exposure to potentially infectious mosquitoes. Eight Anopheles species were recorded. The most numerous species were Anopheles vagus, Anopheles subpictus, and Anopheles hyrcanus. The location of mosquito development sites and the density of larvae in each village was evaluated for correlation with selected demographic, biologic, and land use parameters using remote sensing and geographic information systems (GIS) technology. We found the number of mosquito development sites in a village and the density of larvae in such sites to be positively correlated with human population density but not the surface area (km(2)) of the village. The number of mosquito development sites and the density of larvae in each site were not correlated. Data from this study are being used to construct a GIS-based mapping system that will enable the location of aquatic habitats with Anopheles larvae in the Coimbatore District, Tamil Nadu, India as target sites for the application of vector control. PMID:26364718

  11. Factors Affecting the Distribution of the Amphipod Corophium volutatorin Two Estuaries in South-east England

    NASA Astrophysics Data System (ADS)

    Hughes, R. G.; Gerdol, V.

    1997-05-01

    The distribution of Corophium volutator(Pallas) in the estuaries of the Rivers Blackwater and Crouch in South-east England was examined by taking samples of mud from 137 sites at approximately 0·5 m below mean high water of neap tidal level. Corophium volutatorwere approximately twice as abundant in creeks and semi-enclosed bays than on the open mud flats, a difference that was significant statistically. There was no correlation between the abundance of C. volutatorand the median particle size of the sediment nor the mud content. There was a significant but weak negative correlation between the abundance of C. volutatorand the polychaete Nereis diversicolor. The aggregation of C. volutatorin the creeks and bays was attributed to their dispersal behaviour of swimming on the flood tide, which would sweep the amphipods into such areas where the tide rises but does not flow laterally. On the open mud flats, displacement of swimming amphipods by the flood tide further upstream and into semi-enclosed areas would occur. Their dispersal behaviour places C. volutatorin the creeks and bays within the saltmarsh vegetation, where their bioturbatory feeding habits may be responsible, in part, for the significant loss of pioneer zone vegetation that occurs there.

  12. Environmental factors shaping the abundance and distribution of laccase-encoding bacterial community with potential phenolic oxidase capacity during composting.

    PubMed

    Lu, Lunhui; Zeng, Guangming; Fan, Changzheng; Guo, Jinsong; Zhang, Jiachao; Chen, Ming; Wu, Haipeng; Yuan, Yujie; He, Xiaoxiao; He, Yan

    2015-11-01

    Increasing molecular evidence points to a wide occurrence of laccase-like multicopper oxidase (LMCO)-encoding genes in bacteria. Most researches mainly focused on the bacterial LMCO diversity, whereas the processes and the environmental factors responsible for structuring bacterial LMCO communities remain relatively unknown in a composting system. Six gene libraries were constructed from samples in representative stages during composting. A total of 185 sequences obtained from sample DNA extracts were classified to 59 operational taxonomic units (OTUs) based on 10 % cutoff. The distribution profile of bacterial LMCO genes showed that proteobacterial- and actinobacterial-associated species were the dominant communities during composting. Pearson correlation analysis indicated that the pile temperature and water-soluble carbon (WSC) content were significantly positively correlated with bacterial LMCO gene OTU numbers, Chao1 and Shannon index, whereas the humic acid (HA)-like carbon content had the most significant effect on the distribution of the bacterial LMCO genes during composting by redundancy analysis. These findings will improve the understanding of the mutual relationship between environmental factors and bacterial LMCO community compositions in composting. PMID:26104868

  13. Spatial distribution and factors shaping the niche segregation of ammonia-oxidizing microorganisms in the Qiantang River, China.

    PubMed

    Liu, Shuai; Shen, Lidong; Lou, Liping; Tian, Guangming; Zheng, Ping; Hu, Baolan

    2013-07-01

    Ammonia oxidation is performed by both ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB). However, the current knowledge of the distribution, diversity, and relative abundance of these two microbial groups in freshwater sediments is insufficient. We examined the spatial distribution and analyzed the possible factors leading to the niche segregation of AOA and AOB in the sediments of the Qiantang River, using clone library construction and quantitative PCR for both archaeal and bacterial amoA genes. pH and NH4(+)-N content had a significant effect on AOA abundance and AOA operational taxonomy unit (OTU) numbers. pH and organic carbon content influenced the ratio of AOA/AOB OTU numbers significantly. The influence of these factors showed an obvious spatial trend along the Qiantang River. This result suggested that AOA may contribute more than AOB to the upstream reaches of the Qiantang River, where the pH is lower and the organic carbon and NH4(+)-N contents are higher, but AOB were the principal driver of nitrification downstream, where the opposite environmental conditions were present. PMID:23624482

  14. Receptors for B cell stimulatory factor 2. Quantitation, specificity, distribution, and regulation of their expression

    SciTech Connect

    Taga, T.; Kawanishi, Y.; Hardy, R.R.; Hirano, T.; Kishimoto, T.

    1987-10-01

    B cell stimulatory factor 2 receptors (BSF-2-R) were studied using radioiodinated recombinant BSF-2 with a specific activity of 6.16 X 10(13) cpm/g. Kinetic studies showed that binding of /sup 125/I-BSF-2 to CESS cells reached maximum level within 150 min at 0 degrees C. There was a single class of receptors with high affinity (Kd 3.4 X 10(-10) M) on CESS, and the number of receptors was 2700 per cell. Binding of /sup 125/I-BSF-2 to CESS was competitively inhibited by unlabeled BSF-2 but not by IL-1, IL-2, IFN-beta, IFN-gamma, and G-CSF, indicating the presence of the receptors specific for BSF-2. EBV-transformed B lymphoblastoid cell lines (CESS, SKW6-CL4, LCL13, and LCL14) expressed BSF-2-R, whereas Burkitt's lines did not. EBV or EBNA2 did not induce the expression of the receptors on Burkitt's cells. The plasma cell lines (ARH-77 and U266) expressed BSF-2-R, fitting the function of BSF-2 as plasma cell growth factor. Several other cell lines, the histiocytic line U937, the promyelocytic line HL60, the astrocytoma line U373 and the glioblastoma line SK-MG-4, in which BSF-2 was inducible with IL-1 or TPA, displayed BSF-2-R with Kd in the range of 1.3-6.4 X 10(-10) M, suggesting the autocrine mechanism in BSF-2 function. The four T cell lines (CEM, HSB, Jurkat, and OM 1) did not express a detectable number of receptors, but normal resting T cells expressed 100-1000 receptors per cell. BSF-2-R were not present on normal resting B cells but expressed on activated B cells with a Kd of 3.6-5.0 X 10(-10) M, fitting the function of BSF-2, which acts on B cells at the final maturation stage to induce immunoglobulin production.

  15. Factors affecting phytoplankton distribution and production in the Elephant Island area, Antarctica

    SciTech Connect

    Helbling, E.W.

    1993-01-01

    During the austral summer of four years, 1990 to 1993, studies on phytoplankton were performed in the Elephant Island area as one component of the US Antarctica Marine Living Resources program. In addition to continuous measurements (temperature, salinity, chlorophyll-a, beam attenuation) made on ship's intake water, a profiling CTD-rosette unit was used to obtain water column characteristics (temperature, salinity, chlorophyll-a, attenuation of solar radiation, beam attenuation) from the surface to 750m depth and also water samples from at least 10 depths for chemical and biological analyses. The sampling grid consisted of an average of 70 stations, all of which were occupied two times each year. The Elephant Island area is a transition zone between the rich coastal areas, where phytoplankton can develop dense blooms, and pelagic waters where the phytoplankton biomass is in general very low. A frontal zone was usually found to the north of Elephant Island and over the continental slope, and high phytoplankton biomass was in general associated with this frontal region. Although the location of this frontal system showed seasonal movement in a north-south direction, it seems to be a consistent feature from year to year. There seems to be considerable year-to-year variability in physical (water temperatures and salinity) and phytoplankton characteristics within the study area, in regard to both distributional patterns in surface waters and to profile characteristics in the upper 100m of the water column. With shallow upper mixed layer depths of less than 50 m, phytoplankton can attain relatively high concentrations. Optimum light conditions for growth occurred when the mixed layer was less than 55% of the euphotic zone. As the area around Elephant Island is characterized by relatively strong and frequent winds, the depth of the upper mixed layer at many stations approached the depth of the euphotic zone, with the result that growth of phytoplankton was light limited.

  16. Matrix factorization to time-frequency distribution for structural health monitoring

    NASA Astrophysics Data System (ADS)

    Chang, Chia-Ming; Huang, Shieh-Kung

    2016-04-01

    Structural health monitoring enables structural information to be acquired through sensing technology, and is of need to early detect problems and damages in structures. Health monitoring strategies are often realized through a combination of qualitative sensing systems and high-performance structural integrity assessment methods. Structural deviations can be then effectively identified by interpreting the raw sensor measurements using signal processing techniques. The objective of this study is to develop a new structural health monitoring method that applies a matrix factorization algorithm to a time-frequency representation of multi-channel signals measured from a structure. This method processes vibrational input and/or output responses of structures to improve raw data quality, to estimate structural responses, to derive signal features, and to detect structural variations. For example, the proposed method can reduce the signal noise by utilizing first few principle vectors to reconstruct the measured signals. For frequency-domain responses, this method can smooth the phase to obtain a better input-output relationship of a structure. Additionally, the method removes abnormal signals in time series, allowing better understanding of structural behavior. Due to communication loss, this method is able to recover lost data from other channel measurements in a structure. Moreover, the proposed method transforms the signal components into a specific domain and then yield meaningful characteristics. All these features are numerically verified using experimental data, and the proposed method permits more detailed investigation of structural behavior.

  17. Body fat, fat distribution, and psychosocial factors among patients with Type 2 diabetes mellitus.

    PubMed

    Bell, R A; Summerson, J H; Spangler, J G; Konen, J C

    1998-01-01

    Diabetes, a risk factor for cardiovascular disease, requires lifestyle modifications (diet, exercise, weight loss). The relations between body mass index, waist-hip ratio (WHR), and psychosocial indicators, such as affect and stress, among 302 diabetic patients from a clinic and a neighborhood health center were analyzed. Data included stress and mood scale responses, body size (height, weight, and WHR) and potential confounders (physical activity, energy intake, and diabetes duration). In univariate analyses, body mass index was positively associated with stress and inversely associated with positive affect only in women. Multiple regression analyses indicated that stress was associated with body mass index and negative mood was associated with the WHR. The findings suggested that stress and affect may be important correlates of body fat among women with Type 2 diabetes, leading to more complications. Healthcare providers can help women with Type 2 diabetes lose weight and lower the risk of cardiovascular disease by recognizing and helping them deal with these psychosocial issues. PMID:9850808

  18. Dissipation dynamic, residue distribution and processing factor of hexythiazox in strawberry fruits under open field condition.

    PubMed

    Saber, Ayman N; Malhat, Farag M; Badawy, Hany M A; Barakat, Dalia A

    2016-04-01

    Two independent field trials were performed to investigate the dissipation and residue levels of hexythiazox in strawberry. The study presents a method validation for extraction and quantitative analysis of hexythiazox residues in strawberry using HPLC-DAD. The results shown that the mean recoveries ranged from 85% to 93%, furthermore the intra- and inter-day relative standard deviations were less than 10%. The results suggest that the hexythiazox dissipation curves followed the first-order kinetic and its half-life ranged from 3.43 to 3.81 days. The final residues in strawberry were below the Codex maximum residue limit (MRL) (6 mg/kg) after three days of the application. The effects of household processing and storage on the levels of hexythiazox residues were quantified, and it's useful for reducing the dietary exposure. The processing factor after each stage were generally less than 1, indicating that the whole process can reduce the residues of hexythiazox in strawberry. The results could provide guidance to safe and reasonable use of hexythiazox in agriculture. PMID:26593595

  19. The potential distribution and the short-circuiting factor in the sucrose gap.

    PubMed

    Jirounek, P; Straub, R W

    1971-01-01

    The sucrose gap technique, though widely employed in many tissues, could not be used for quantitative measurements of the membrane potential, because the value of the short-circuiting factor and the influence of junction potential on the recorded potential difference were unknown. The formula that relates the recorded potential to the true resting membrane potential was found by application of the cable equations to a core conductor placed in a system with three different media, e.g. Ringer, sucrose, and KCl. The formula shows that the potential difference recorded over the sucrose insulator depends on the extracellular and the intracellular longitudinal resistances, the membrane resistance and the membrane potentials in each region, and on the junction potentials between the different media. The true membrane potential in the Ringer region can be calculated from the potential difference recorded after complete depolarization by KCl on one side of the preparation, if the longitudinal resistances, the membrane resistances, the extracellular potential in the sucrose, and the junction potential between Ringer and sucrose are determined by separate measurements. PMID:5538998

  20. Effects of retorting factors on combustion properties of shale char. 3. Distribution of residual organic matters.

    PubMed

    Han, Xiangxin; Jiang, Xiumin; Cui, Zhigang; Liu, Jianguo; Yan, Junwei

    2010-03-15

    Shale char, formed in retort furnaces of oil shale, is classified as a dangerous waste containing several toxic compounds. In order to retort oil shale to produce shale oil as well as treat shale char efficiently and in an environmentally friendly way, a novel kind of comprehensive utilization system was developed to use oil shale for shale oil production, electricity generation (shale char fired) and the extensive application of oil shale ash. For exploring the combustion properties of shale char further, in this paper organic matters within shale chars obtained under different retorting conditions were extracted and identified using a gas chromatography-mass spectrometry (GC-MS) method. Subsequently, the effects of retorting factors, including retorting temperature, residence time, particle size and heating rate, were analyzed in detail. As a result, a retorting condition with a retorting temperature of 460-490 degrees C, residence time of <40 min and a middle particle size was recommended for both keeping nitrogenous organic matters and aromatic hydrocarbons in shale char and improving the yield and quality of shale oil. In addition, shale char obtained under such retorting condition can also be treated efficiently using a circulating fluidized bed technology with fractional combustion. PMID:19896769

  1. Factors that explain how policy makers distribute resources to mental health services.

    PubMed

    Corrigan, Patrick W; Watson, Amy C

    2003-04-01

    Advocates hope to influence the resource allocation decisions of legislators and other policy makers to capture more resources for mental health programs. Findings from social psychological research suggest factors that, if pursued, may improve advocacy efforts. In particular, allocation decisions are affected by policy makers' perceptions of the scarcity of resources, effectiveness of specific programs, needs of people who have problems that are served by these programs, and extent of personal responsibility for these problems. These perceptions are further influenced by political ideology. Conservatives are motivated by a tendency to punish persons who are perceived as having personal responsibility for their problems by withholding resources, whereas liberals are likely to avoid tough allocation decisions. Moreover, these perceptions are affected by political accountability, that is, whether politicians perceive that their constituents will closely monitor their decisions. Just as the quality of clinical interventions improves when informed by basic research on human behavior, the efforts of mental health advocates will be advanced when they understand the psychological forces that affect policy makers' decisions about resources. PMID:12663837

  2. Equilibrium and kinetic Si isotope fractionation factors and their implications on Si isotope distributions in the Earth's surface environments

    NASA Astrophysics Data System (ADS)

    Tang, M.; Zhang, S.; Liu, Y.

    2015-12-01

    Several important equilibrium Si isotope fractionation factors among minerals, organic molecules and the H4SiO4 solution are complemented to facilitate explanation of distributions of Si isotope in the Earth's surface environments. The results reveal that heavy Si isotopes will be significantly enriched in the secondary silicate minerals in comparison to aqueous H4SiO4. On the contrary, quadra-coordinated organosilicon complexes are enriched in light silicon isotope relative to the solution. The extent of 28Si-enrichment in hyper-coordinated organosilicon complexes is found the largest. In addition, the large kinetic isotope effect associated with the polymerization of monosilicic acid and dimer is calculated and the result supports previous statement that highly 28Si-enrichment in the formation of amorphous quartz precursor contributes to the discrepancy between theoretical calculations and field observations. With equilibrium Si isotope fractionation factors provided here, Si isotope distributions in many surface systems of the Earth can be explained. For example, the change of bulk soil δ30Si can be predicted as a concave pattern with respect to weathering degree, with the minimum value where allophane completely dissolves and the total amount of sesqui-oxides and poorly crystalline minerals reaches its maximum. When well-crystallized clays start to precipitate from pore solutions under equilibrium conditions, the bulk soil δ30Si will increase again and reach a constant value. Similarly, the precipitation of crystalline smectite and the dissolution of poorly crystalline kaolinite may explain δ30Si variations in the ground water profile. Equilibrium Si isotope fractionations among quadra-coordinated organosilicon complexes and the H4SiO4 solution may also shed the light on the Si isotope distributions in Si-accumulating plants.

  3. Insecticide resistance in the dengue vector Aedes aegypti from Martinique: distribution, mechanisms and relations with environmental factors.

    PubMed

    Marcombe, Sébastien; Mathieu, Romain Blanc; Pocquet, Nicolas; Riaz, Muhammad-Asam; Poupardin, Rodolphe; Sélior, Serge; Darriet, Frédéric; Reynaud, Stéphane; Yébakima, André; Corbel, Vincent; David, Jean-Philippe; Chandre, Fabrice

    2012-01-01

    Dengue is an important mosquito borne viral disease in Martinique Island (French West Indies). The viruses responsible for dengue are transmitted by Aedes aegypti, an indoor day-biting mosquito. The most effective proven method for disease prevention has been by vector control by various chemical or biological means. Unfortunately insecticide resistance has already been observed on the Island and recently showed to significantly reduce the efficacy of vector control interventions. In this study, we investigated the distribution of resistance and the underlying mechanisms in nine Ae. aegypti populations. Statistical multifactorial approach was used to investigate the correlations between insecticide resistance levels, associated mechanisms and environmental factors characterizing the mosquito populations. Bioassays revealed high levels of resistance to temephos and deltamethrin and susceptibility to Bti in the 9 populations tested. Biochemical assays showed elevated detoxification enzyme activities of monooxygenases, carboxylesterases and glutathione S-tranferases in most of the populations. Molecular screening for common insecticide target-site mutations, revealed the presence of the "knock-down resistance" V1016I Kdr mutation at high frequency (>87%). Real time quantitative RT-PCR showed the potential involvement of several candidate detoxification genes in insecticide resistance. Principal Component Analysis (PCA) performed with variables characterizing Ae. aegypti from Martinique permitted to underline potential links existing between resistance distribution and other variables such as agriculture practices, vector control interventions and urbanization. Insecticide resistance is widespread but not homogeneously distributed across Martinique. The influence of environmental and operational factors on the evolution of the resistance and mechanisms are discussed. PMID:22363529

  4. Utility of Red Cell Distribution Width as a Prognostic Factor in Young Breast Cancer Patients

    PubMed Central

    Huang, Du-Ping; Ma, Rui-Min; Xiang, You-Qun

    2016-01-01

    Abstract The prognosis of breast cancer occurs in young women is usually poor. Red cell distribution width (RDW), 1 of many routinely examined parameters, has recently been proposed as a prognostic marker in solid tumors. The aim of our study was to assess the predictive value of RDW for survival in young women with breast cancer. We reviewed 203 consecutive young female patients (under 40) with invasive breast cancer diagnosed at the First Affiliated Hospital of Wenzhou Medical University between January 2008 and December 2012. Preoperational RDW, clinicopathological information, and prognostic data were collected. RDW levels were divided into 2 groups: 161 patients with low RDW (≤13.75%) and 42 patients with high RDW (>13.75%). Clinicopathological differences between the 2 groups were calculated by chi-squared test and Wilcoxon rank-sum test. Kaplan–Meier survival analysis and Cox proportional hazard regression analyses were used to examine the effect of RDW on survival. We found that high RDW was significantly associated with larger tumor size (P = 0.002), positive lymph node metastases (P = 0.011), and advanced stages (P = 0.004). Patients with high RDW showed significantly lower disease-free survival (DFS; P < 0.001) and lower overall survival (OS) rate (P < 0.001) than patients with low RDW. Moreover, the Cox regression multivariate analysis revealed that high pretreatment DRW was independently correlated with poor DFS and OS, with hazard ratio 4.819 (95% confidence interval [CI] 2.291–10.138, P < 0.001) and 5.887 (95% CI 1.666–20.802, P = 0.006), respectively. In conclusion, our study demonstrated that pretreatment RDW may be associated with DFS and OS in young women with breast cancer. Further validation and feasibility studies are required before the result of our study can be considered for clinical practice. PMID:27124030

  5. C2362F mutation gives rise to an ADAMTS13-resistant von Willebrand factor.

    PubMed

    Casonato, Alessandra; Pontara, Elena; Battiston, Monica; Morpurgo, Margherita; Cattini, Maria Grazia; Casarin, Elisabetta; Saga, Giorgia; Daidone, Viviana; De Marco, Luigi

    2013-06-01

    von Willebrand factor (VWF) multimers result from proteolysis by the metalloprotease ADAMTS13. Since C2362F-VWF features abnormally large multimers with their triplet oligomer structure replaced by a diffuse smear, we explored the susceptibility of C2362F-VWF to ADAMTS13. VWF-enriched blood samples, obtained by cryoethanol precipitation of plasma from a patient with von Willebrand disease (VWD) homozygous for the C2362F mutation and a normal subject, were submitted to cleavage by recombinant ADAMTS13 under static conditions in the presence of urea. C2362F-VWF proved completely ADAMTS13-resistant in vitro. At any concentration of recombinant ADAMTS13 (from 0.1 µM to 1 µM), there was no evidence of the abnormally large VWF multimers of C2362F-VWF disappearing, nor any increased representation of triplet multimer bands, unlike the situation seen in normal VWF. This is due partly to a defective ADAMTS13 binding to C2362F-VWF under static conditions, as seen in both the patient's and recombinant mutated VWF proteins. These findings were associated with a significantly shorter than normal survival of C2362F-VWF after DDAVP, demonstrating that proteolysis and VWF survival may be independent phenomena. Our findings clearly demonstrate that the loss of cysteine 2362 makes VWF resistant to proteolysis by ADAMTS13, at least partly due to an impaired ADAMTS13 binding to VWF. This suggests that the B2 domain of VWF is involved in modulating ADAMTS13 binding to VWF and the consequent proteolytic process. The C2362F-VWF mutation also enables a new abnormality to be identified in the VWF-ADAMTS13 relationship, i.e. an ADAMTS13-resistant VWF. PMID:23446343

  6. Distribution of asthma by occupation: Washington State Behavioral Risk Factor Surveillance System Data, 2006–2009

    PubMed Central

    Fan, Zihong Joyce; Reeb-Whitaker, Carolyn; Bonauto, David K.; Rauser, Edmund

    2014-01-01

    Objective Objective: To estimate the prevalence of asthma in workers by occupation in Washington State. Methods: Data from the 2006–2009 Behavioral Risk Factor Surveillance System (BRFSS) and the BRFSS Asthma Call-Back Survey (ACBS) in Washington State (WA) were analyzed. Using state-added and coded Industry and Occupation questions, we calculated prevalence ratios (PRs) for 19 occupational groups. Results: Of the 41 935 respondents who were currently employed during 2006–2009, the prevalence of current asthma was 8.1% [95% confidence interval (CI) 7.8–8.5%] When compared with the reference group of executive, administration and managerial occupations, three occupational groups had significantly (p < 0.05) higher PRs of current asthma: “Teachers, all levels, and Counselors’ (PR 1.3, 95% CI 1.1–1. 6%); ‘Administrative Support, including Clerical” (PR 1. 5, 95% CI 1.2–1.9%); and “Other Health Services” (PR 1.5, 95% CI 1.2–1.9). Half of the 2511 ACBS respondent workers (55.1%) indicated that they believed exposure at work had caused or worsened their asthma, but only 10.7% had ever spoken with a health care professional about their asthma being work related. Conclusions: Some occupations have a higher prevalence of current asthma than other occupations. The systematic collection of industry and occupation data can help identify worker populations with a high burden of asthma and can be used to target disease prevention efforts as well as to aid clinician recognition and treatment. Workers indicated that work-related asthma exposures are not discussed with their health care provider and this communication gap has implications for asthma management. PMID:24995660

  7. Correlation of Spatio-Temporal Contaminant Distribution, Land Use, and Hydrogeological Factors in the Karst Aquifers of Northern Puerto Rico

    NASA Astrophysics Data System (ADS)

    Torres Torres, N. I.; Padilla, I. Y.

    2015-12-01

    Karst aquifers are characterized by caves, springs, and sinkholes, and typified by interconnected fissures, fractures and conduits. These characteristics make these aquifers highly productive, and vulnerable to contamination. Previous studies in the northern karst aquifers of Puerto Rico have shown significant distribution of contaminants, including volatile organic compounds, phthalates and other contaminants of emerging concern, beyond demarked sources of contamination. This study develops spatial-temporal distributions of phthalate contaminants in the karst system of northern Puerto Rico and assesses statistical correlations between hydrogeologic factors and groundwater contamination with phthalates. Geographic Information Systems (GIS) tools and technologies, and statistical models are applied to attain these objectives. Results show that there is an extensive contamination with phthalates that varies with time. Contamination is present in the confined and shallow aquifers. Di-(2-ethylhexyl) phthalate (DEHP) is the most detected contaminant (20.6% of the sites). Diethyl phthalate and and dibutyl phthalate are also detected in 6.7% and 8.24% of the sites, respectively. Phthalates detected as mixtures components are significantly detected in areas of high urban and industrial development. They are also detected in areas within 5 miles of superfund sites and landfills. The results indicate that phthalate contamination is highly related to land use. Statistical models show that the hydraulic conductivity of the aquifers, sinkholes density, and time are significantly related to the presence of phthalates in groundwater. The extensive spatio-temporal contamination suggests that contaminants can persist in the environment for long periods of time, and that land use and hydrogeological factors are important factors contributing to the presence of emerging contaminants in karst systems.

  8. Differences in human skin between the epidermal growth factor receptor distribution detected by EGF binding and monoclonal antibody recognition.

    PubMed

    Green, M R; Couchman, J R

    1985-09-01

    Two methods have been used to examine epidermal growth factor (EGF) receptor distribution in human scalp and foreskin. The first employed [125I]EGF viable explants and autoradiography to determine the EGF binding pattern while the second used a monoclonal antibody to the human EGF receptor to map the distribution on frozen skin sections of an extracellular epitope on the EGF receptor. The [125I]EGF binding experiments showed accessible, unoccupied EGF receptors to be present on the epidermal basal cells (with reduced binding to spinous cells), the basal cells of the hair shaft and sebaceous gland, the eccrine sweat glands, capillary system, and the hair follicle outer root sheath, generally similar in pattern to that previously reported for full-thickness rat skin and human epidermis. The same areas also bound EGF-R1 but in addition the monoclonal antibody recognized a cone of melanin containing presumptive cortex cells, excluding the medulla, lying around and above the upper dermal papilla of anagen hair follicles, epithelial cells around the lower dermal papilla region, and in some tissue samples the cell margins of the viable differentiating layers of the epidermis. In a control study, to clarify whether EGF-R1 could recognize molecules unrelated to the EGF receptor, the EGF binding and EGF-R1 recognition profiles were compared on cultures of SVK14 cells, a SV40 transformed human keratinocyte cell line. EGF binding and EGF-R1 monoclonal antibody distribution on these cells was found to be similar, indicating that, at least for SVK14 cells, EGF-R1 binding provides a reliable marker for EGF binding. Explanations for the discrepancies between these two methods for determining EGF receptor distribution in human skin are discussed, including the possibility that latent EGF receptors, unable to bind [125I]EGF, may be present in some differentiating epithelial compartments. PMID:2411822

  9. Controlling factors analysis of pCO2 distribution in the Western Arctic Ocean in summertime

    NASA Astrophysics Data System (ADS)

    Song, Xuelian; Bai, Yan; Hao, Zengzhou; Zhun, Qiankun; Chen, Jianyu; Gong, Fang

    2015-10-01

    The uptake of carbon dioxide (CO2) by the Arctic Ocean has been changing because of the rapid sea-ice retreat with global warming. The Chukchi Sea is the only gateway of the warm and nutrient-rich Pacific Ocean water flowing into the North Pole, and the high productivity-water had great impact on the CO2 uptake by the Arctic Ocean. We used the in situ underway data of aquatic partial pressure of CO2 (pCO2), temperature and salinity, as well as the remote sensing data of sea ice concentration, chlorophyll concentration, sea surface temperature in August in 2008, 2011 and 2012 to analyze the major controlling factors of aquatic pCO2 in the Western Arctic Ocean. We analyzed the pCO2 variation under the effects of thermodynamic process (temperature), mixing of water mass (salinity), biological drawdown (chlorophyll), and sea ice concentration. The aquatic pCO2 was generally unsaturation relative to the atmospheric CO2 in most of the Western Arctic Ocean. According to different controlling mechanisms, the study area was divided into three parts: the area affected by the Pacific Ocean water (mainly in the Chukchi Sea), the area where sea ice mostly melted with weak biological production (the southern Canada Basin and the Western Beaufort Sea), and the area mostly covered by sea ice (the Northern Canada Basin). The aquatic pCO2 was low in the Chukchi Sea with the influence of the Pacific Ocean water. While, pCO2 in the area where sea ice melted was up to 360-380 μatm because of warming, CO2 invasion from the atmosphere, and a low biological production. For the Canada Basin, it was controlled by temperature change and sea ice cover. The remote sensing data in large spatial-temporal scale can help to understand the pCO2 variation and its response to global change; and it needs to develop satellite algorithm of pCO2 based on the quantification of controlling processes.

  10. Key Factors Controlling Space- and Time-Linked Rare Earth Element Distribution in Shallow Groundwaters

    NASA Astrophysics Data System (ADS)

    Dia, A.; Gruau, G.; Olivie-Lauquet, G.; Henin, O.; Petitjean, P.; Le Coz-Bouhnik, M.

    2001-12-01

    comparison of the different catchments shows that the spatial variability of the REE signatures between the hillslope DOC-poor groundwaters and the wetland DOC-rich groundwaters has to be the same whatever may be the climatic and geologic context. These results assess the key roles played in the REE transfer to hydrosystems by (i) the occurrence of organic compounds, acting as a trace-element carrier phase and (ii) redox condition changes. Finally, we propose that topography could be the ultimate key factor, through its ability to control the water table depth and therefore the organic colloids enrichment when groundwaters are flowing into organic-rich soil horizons.

  11. Setting limits: The development and use of factor-ceiling distributions for an urban assessment using macroinvertebrates

    USGS Publications Warehouse

    Carter, J.L.; Fend, S.V.

    2005-01-01

    Lotic habitats in urban settings are often more modified than in other anthropogenically influenced areas. The extent, degree, and permanency of these modifications compromise the use of traditional reference-based study designs to evaluate the level of lotic impairment and establish restoration goals. Directly relating biological responses to the combined effects of urbanization is further complicated by the nonlinear response often observed in common metrics (e.g., Ephemeroptera, Plecoptera, and Trichoptera [EPT] species richness) to measures of human influence (e.g., percentage urban land cover). A characteristic polygonal biological response often arises from the presence of a generalized limiting factor (i.e., urban land use) plus the influence of multiple additional stressors that are nonuniformly distributed throughout the urban environment. Benthic macroinvertebrates, on-site physical habitat and chemistry, and geographical information systems-derived land cover data for 85 sites were collected within the 1,600-km2 Santa Clara Valley (SCV), California urban area. A biological indicator value was derived from EPT richness and percentage EPT. Partitioned regression was used to define reference conditions and estimate the degree of site impairment. We propose that an upper-boundary condition (factor-ceiling) modeled by partitioned regression using ordinary least squares represents an attainable upper limit for biological condition in the SCV area. Indicator values greater than the factor-ceiling, which is monotonically related to existing land use, are considered representative of reference conditions under the current habitat conditions imposed by existing land cover and land use.

  12. Wet and dry deposition of mineral dust particles in Japan: factors related to temporal variation and spatial distribution

    NASA Astrophysics Data System (ADS)

    Osada, K.; Ura, S.; Kagawa, M.; Mikami, M.; Tanaka, T. Y.; Matoba, S.; Aoki, K.; Shinoda, M.; Kurosaki, Y.; Hayashi, M.; Shimizu, A.; Uematsu, M.

    2013-08-01

    Data of temporal variations and spatial distributions of mineral dust deposition fluxes are very limited in terms of duration, location, and processes of deposition. To ascertain temporal variations and spatial distributions of mineral dust deposition by wet and dry processes, weekly deposition samples were obtained at Sapporo, Toyama, Nagoya, Tottori, Fukuoka, and Cape Hedo (Okinawa) in Japan during October 2008-December 2010 using automatic wet and dry separating samplers. Mineral dust weights in water-insoluble residue were estimated from Fe contents measured using an X-ray fluorescence analyzer. For wet deposition, highest and lowest annual dust fluxes were found at Toyama (9.6 g m-2 yr-1) and at Cape Hedo (1.7 g m-2 yr-1) as average values in 2009 and 2010. Higher wet deposition fluxes were observed at Toyama and Tottori, where frequent precipitation (>60% days per month) was observed during dusty seasons. For dry deposition among Toyama, Tottori, Fukuoka, and Cape Hedo, the highest and lowest annual dust fluxes were found respectively at Fukuoka (5.2 g m-2 yr-1) and at Cape Hedo (2.0 g m-2 yr-1) as average values in 2009 and 2010. Although the seasonal tendency of the monthly dry deposition amount roughly resembled that of monthly days of Kosa dust events, the monthly amount of dry deposition was not proportional to monthly days of the events. Comparison of dry deposition fluxes with vertical distribution of dust particles deduced from Lidar data and coarse particle concentrations suggested that the maximum dust layer height or thickness is an important factor for controlling the dry deposition amount after long-range transport of dust particles. Size distributions of refractory dust particles were obtained using four-stage filtration: >20, >10, >5, and >1 μm diameter. Weight fractions of the sum of >20 μm and 10-20 μm (giant fraction) were higher than 50% for most of the event samples. Irrespective of the deposition type, the giant dust fractions were

  13. Hyperosmotic stress regulates the distribution and stability of myocardin-related transcription factor, a key modulator of the cytoskeleton.

    PubMed

    Ly, Donald L; Waheed, Faiza; Lodyga, Monika; Speight, Pam; Masszi, András; Nakano, Hiroyasu; Hersom, Maria; Pedersen, Stine F; Szászi, Katalin; Kapus, András

    2013-01-15

    Hyperosmotic stress initiates several adaptive responses, including the remodeling of the cytoskeleton. Besides maintaining structural integrity, the cytoskeleton has emerged as an important regulator of gene transcription. Myocardin-related transcription factor (MRTF), an actin-regulated coactivator of serum response factor, is a major link between the actin skeleton and transcriptional control. We therefore investigated whether MRTF is regulated by hyperosmotic stress. Here we show that hypertonicity induces robust, rapid, and transient translocation of MRTF from the cytosol to the nucleus in kidney tubular cells. We found that the hyperosmolarity-triggered MRTF translocation is mediated by the RhoA/Rho kinase (ROK) pathway. Moreover, the Rho guanine nucleotide exchange factor GEF-H1 is activated by hyperosmotic stress, and it is a key contributor to the ensuing RhoA activation and MRTF translocation, since siRNA-mediated GEF-H1 downregulation suppresses these responses. While the osmotically induced RhoA activation promotes nuclear MRTF accumulation, the concomitant activation of p38 MAP kinase mitigates this effect. Moderate hyperosmotic stress (600 mosM) drives MRTF-dependent transcription through the cis-element CArG box. Silencing or pharmacological inhibition of MRTF prevents the osmotic stimulation of CArG-dependent transcription and renders the cells susceptible to osmotic shock-induced structural damage. Interestingly, strong hyperosmolarity promotes proteasomal degradation of MRTF, concomitant with apoptosis. Thus, MRTF is an osmosensitive and osmoprotective transcription factor, whose intracellular distribution is regulated by the GEF-H1/RhoA/ROK and p38 pathways. However, strong osmotic stress destabilizes MRTF, concomitant with apoptosis, implying that hyperosmotically induced cell death takes precedence over epithelial-myofibroblast transition, a potential consequence of MRTF-mediated phenotypic reprogramming. PMID:23054059

  14. Analysis of Blood Glucose Distribution Characteristics and Its Risk Factors among a Health Examination Population in Wuhu (China)

    PubMed Central

    Song, Jiangen; Zha, Xiaojuan; Li, Haibo; Guo, Rui; Zhu, Yu; Wen, Yufeng

    2016-01-01

    Background: Diabetes mellitus (DM) and Impaired Fasting Glucose (IFG) represent serious threats to human health, and as a result, this study was aimed at understanding the blood glucose distribution characteristics and the risk factors among a large health examination population in China. Methods: An investigation with physical and biochemical examinations and questionnaires was conducted in the physical examination center from 2011 to 2014 and as a result 175,122 physical examination attendees were enrolled in this study. Multivariate logistic regression was used to explore the factors influencing blood sugar levels. Results: The rates of IFG and DM were 6.0% and 3.8%. Prevalence were 7.6%/5.1% in males and 5.1%/2.8% in females for IFG and DM, respectively. The prevalence of IFG and DM were thus higher in males than in females. In the normal group, except high density lipoprotein (HDL) that was significantly higher than in the IFG and DM group, the other indexes (age, body mass index (BMI), glucose (Glu), total cholesterol (TC) and total glycerides (TG) were lower than those in the IFG and DM group. The proportion of IFG and DM also increased with the increases in proportion of abnormal blood pressure, smoking and alcohol consumption. Multivariate logistic regression analysis showed that increasing age, high BMI, high TC, high TG and low HDL increased the risk of diabetes, while in males, in addition to the above factors, the smoking and drinking factors also increased the risk of diabetes. After the age of 65, the blood glucose level reached a peak in males, while in females, the increasing trends was on the rise. The inflexion age of the fast rise was younger in males than in females. Conclusion: The study population showed a high prevalence of DM and IFG among the adults. Regular physical examination for the early detection of diabetes is recommended in the high-risk population. PMID:27043603

  15. Hyperosmotic stress regulates the distribution and stability of myocardin-related transcription factor, a key modulator of the cytoskeleton

    PubMed Central

    Ly, Donald L.; Waheed, Faiza; Lodyga, Monika; Speight, Pam; Masszi, András; Nakano, Hiroyasu; Hersom, Maria; Pedersen, Stine F.; Szászi, Katalin

    2013-01-01

    Hyperosmotic stress initiates several adaptive responses, including the remodeling of the cytoskeleton. Besides maintaining structural integrity, the cytoskeleton has emerged as an important regulator of gene transcription. Myocardin-related transcription factor (MRTF), an actin-regulated coactivator of serum response factor, is a major link between the actin skeleton and transcriptional control. We therefore investigated whether MRTF is regulated by hyperosmotic stress. Here we show that hypertonicity induces robust, rapid, and transient translocation of MRTF from the cytosol to the nucleus in kidney tubular cells. We found that the hyperosmolarity-triggered MRTF translocation is mediated by the RhoA/Rho kinase (ROK) pathway. Moreover, the Rho guanine nucleotide exchange factor GEF-H1 is activated by hyperosmotic stress, and it is a key contributor to the ensuing RhoA activation and MRTF translocation, since siRNA-mediated GEF-H1 downregulation suppresses these responses. While the osmotically induced RhoA activation promotes nuclear MRTF accumulation, the concomitant activation of p38 MAP kinase mitigates this effect. Moderate hyperosmotic stress (600 mosM) drives MRTF-dependent transcription through the cis-element CArG box. Silencing or pharmacological inhibition of MRTF prevents the osmotic stimulation of CArG-dependent transcription and renders the cells susceptible to osmotic shock-induced structural damage. Interestingly, strong hyperosmolarity promotes proteasomal degradation of MRTF, concomitant with apoptosis. Thus, MRTF is an osmosensitive and osmoprotective transcription factor, whose intracellular distribution is regulated by the GEF-H1/RhoA/ROK and p38 pathways. However, strong osmotic stress destabilizes MRTF, concomitant with apoptosis, implying that hyperosmotically induced cell death takes precedence over epithelial-myofibroblast transition, a potential consequence of MRTF-mediated phenotypic reprogramming. PMID:23054059

  16. Analysis of Impact of Geographical Environment and Socio-economic Factors on the Spatial Distribution of Kaohsiung Dengue Fever Epidemic

    NASA Astrophysics Data System (ADS)

    Hsu, Wei-Yin; Wen, Tzai-Hung; Yu, Hwa-Lung

    2013-04-01

    Taiwan is located in subtropical and tropical regions with high temperature and high humidity in the summer. This kind of climatic condition is the hotbed for the propagation and spread of the dengue vector mosquito. Kaohsiung City has been the worst dengue fever epidemic city in Taiwan. During the study period, from January 1998 to December 2011, Taiwan CDC recorded 7071 locally dengue epidemic cases in Kaohsiung City, and the number of imported case is 118. Our research uses Quantile Regression, a spatial infection disease distribution, to analyze the correlation between dengue epidemic and geographic environmental factors and human society factors in Kaohsiung. According to our experiment statistics, agriculture and natural forest have a positive relation to dengue fever(5.5~34.39 and 3.91~15.52). The epidemic will rise when the ratio for agriculture and natural forest increases. Residential ratio has a negative relation for quantile 0.1 to 0.4(-0.005~-0.78), and a positive relation for quantile 0.5 to0.9(0.01~18.0) . The mean income is also a significant factor in social economy field, and it has a negative relation to dengue fever(-0.01~-0.04). Conclusion from our research is that the main factor affecting the degree of dengue fever in predilection area is the residential proportion and the ratio of agriculture and natural forest plays an important role affecting the degree of dengue fever in non predilection area. Moreover, the serious epidemic area located by regression model is the same as the actual condition in Kaohsiung. This model can be used to predict the serious epidemic area of dengue fever and provide some references for the Health Agencies

  17. Aerosol and NOx emission factors and submicron particle number size distributions in two road tunnels with different traffic regimes

    NASA Astrophysics Data System (ADS)

    Imhof, D.; Weingartner, E.; Prévôt, A. S. H.; Ordóñez, C.; Kurtenbach, R.; Wiesen, P.; Rodler, J.; Sturm, P.; McCrae, I.; Ekström, M.; Baltensperger, U.

    2006-06-01

    Measurements of aerosol particle number size distributions (18-700 nm), mass concentrations (PM2.5 and PM10) and NOx were performed in the Plabutsch tunnel, Austria, and in the Kingsway tunnel, United Kingdom. These two tunnels show different characteristics regarding the roadway gradient, the composition of the vehicle fleet and the traffic frequency. The submicron particle size distributions contained a soot mode in the diameter range D=80-100 nm and a nucleation mode in the range of D=20-40 nm. In the Kingsway tunnel with a significantly lower particle number and volume concentration level than in the Plabutsch tunnel, a clear diurnal variation of nucleation and soot mode particles correlated to the traffic density was observed. In the Plabutsch tunnel, soot mode particles also revealed a diurnal variation, whereas no substantial variation was found for the nucleation mode particles. During the night a higher number concentration of nucleation mode particles were measured than soot mode particles and vice versa during the day. In this tunnel with very high soot emissions during daytime due to the heavy-duty vehicle (HDV) share of 18% and another 40% of diesel driven light-duty vehicles (LDV) semivolatile species condense on the pre-existing soot surface area rather than forming new particles by homogeneous nucleation. With the low concentration of soot mode particles in the Kingsway tunnel, also the nucleation mode particles exhibit a diurnal variation. From the measured parameters real-world traffic emission factors were estimated for the whole vehicle fleet as well as differentiated into the two categories LDV and HDV. In the particle size range D=18-700 nm, each vehicle of the mixed fleet emits (1.50±0.08)×1014 particles km-1 (Plabutsch) and (1.26±0.10)×1014 particles km-1 (Kingsway), while particle volume emission factors of 0.209±0.008 cm3 km-1 and 0.036±0.004 cm3 km-1, respectively, were obtained. PM1 emission factors of 104±4 mg km-1 (Plabutsch

  18. Aerosol and NOx emission factors and submicron particle number size distributions in two road tunnels with different traffic regimes

    NASA Astrophysics Data System (ADS)

    Imhof, D.; Weingartner, E.; Prévát, A. S. H.; Ordóñez, C.; Kurtenbach, R.; Wiesen, P.; Rodler, J.; Sturm, P.; McCrae, I.; Sjödin, Å.; Baltensperger, U.

    2005-07-01

    Measurements of aerosol particle number size distributions (18-700 nm), mass concentrations (PM2.5 and PM10) and NOx were performed in the Plabutsch tunnel, Austria, and in the Kingsway tunnel, United Kingdom. These two tunnels show different characteristics regarding the roadway gradient, the composition of the vehicle fleet and the traffic frequency. The submicron particle size distributions contained a soot mode in the diameter range D=80-100 nm and a nucleation mode in the range of D=20-40 nm. In the Kingsway tunnel with a significantly lower particle number and volume concentration level than in the Plabutsch tunnel, a clear diurnal variation of nucleation and soot mode particles correlated to the traffic density was observed. In the Plabutsch tunnel, soot mode particles also revealed a diurnal variation, whereas no substantial variation was found for the nucleation mode particles. During the night a higher number concentration of nucleation mode particles were measured than soot mode particles and vice versa during the day. In this tunnel with very high soot emissions during daytime due to the heavy-duty vehicle (HDV) share of 18% and another 40% of diesel driven light-duty vehicles (LDV) semivolatile species condense on the pre-existing soot surface area rather than forming new particles by homogeneous nucleation. With the low concentration of soot mode particles in the Kingsway tunnel, also the nucleation mode particles exhibit a diurnal variation. From the measured parameters real-world traffic emission factors were estimated for the whole vehicle fleet as well as differentiated into the two categories LDV and HDV. In the particle size range D=18-700 nm, each vehicle of the mixed fleet emits (1.50±0.08)·1014 particles km-1 (Plabutsch) and (1.26±0.10)·1014 particles km-1 (Kingsway), while particle volume emission factors of 0.209±0.008 cm3 km-1 and 0.036±0.004 cm3 km-1, respectively, were obtained. PM1 emission factors of 104±4 mg km-1 (Plabutsch

  19. An examination of factors influencing the spatial distribution of foraging bats in pine stands in the southeastern United States.

    SciTech Connect

    Menzel, Michael, A., Jr.

    2003-01-01

    Menzel, M.A. 2003. An examination of factors influencing the spatial distribution of foraging bats in pine stands in the Southeastern United States. Ph.D Dissertation. Davis College of Agriculture, Forestry and Consumer Sciences at West Virginia University, Morgantown, West Virginia. 336 pp. The general objective of this dissertation was to determine the effect of changes in forest structure on bat activity patterns in southern pine stands. Four sub studies are included in the dissertation: (1) An examination of the homerange size, habitat use and diet of four reproductively active male Rafinesque's big eared bats (Corynorhimus rafinesquii); (2) An examination of the diet of 5 reproductively active male Rafinesque's big eared bats; (3) A comparison of bat activity levels in the Coastal Plain of South Carolina among 5 vegetational community types: forested riparian areas, clearcuts, young pine plantations, mature plantations, and pine savannahs; (4) A summarization of information concerning the natural history of all bat species common in the SPR.

  20. Prevalence and organ distribution of leukocyte chemotactic factor 2 amyloidosis (ALECT2) among decedents in New Mexico

    PubMed Central

    Larsen, Christopher P.; Beggs, Marjorie L.; Wilson, Jon D.; Lathrop, Sarah L.

    2016-01-01

    Abstract Leukocyte chemotactic factor 2 (LECT2) amyloidosis is one of the most recently described types of amyloidosis. Since its description, it has been found to be one the most common types of amyloidosis in large series of amyloid cases involving the kidney and liver in the United States, where it primarily affects patients of Hispanic ethnicity. We sought to investigate the prevalence of this disease among Hispanic adult decedents who had an autopsy performed at the New Mexico Office of the Medical Investigator and determine the organ distribution of amyloid deposition. LECT2 amyloid deposits were identified within the kidney in 3.1% of Hispanic decedents. It was consistently deposited in the liver, spleen, adrenals, and lungs but did not involve the myocardium or brain. LECT2 amyloidosis is likely not rare among Hispanics in the Southwest United States and could represent an important but under-recognized etiology of chronic kidney disease in this population. PMID:26912093

  1. Prevalence and organ distribution of leukocyte chemotactic factor 2 amyloidosis (ALECT2) among decedents in New Mexico.

    PubMed

    Larsen, Christopher P; Beggs, Marjorie L; Wilson, Jon D; Lathrop, Sarah L

    2016-06-01

    Leukocyte chemotactic factor 2 (LECT2) amyloidosis is one of the most recently described types of amyloidosis. Since its description, it has been found to be one the most common types of amyloidosis in large series of amyloid cases involving the kidney and liver in the United States, where it primarily affects patients of Hispanic ethnicity. We sought to investigate the prevalence of this disease among Hispanic adult decedents who had an autopsy performed at the New Mexico Office of the Medical Investigator and determine the organ distribution of amyloid deposition. LECT2 amyloid deposits were identified within the kidney in 3.1% of Hispanic decedents. It was consistently deposited in the liver, spleen, adrenals, and lungs but did not involve the myocardium or brain. LECT2 amyloidosis is likely not rare among Hispanics in the Southwest United States and could represent an important but under-recognized etiology of chronic kidney disease in this population. PMID:26912093

  2. Determination of Key Environmental Factors Responsible for Distribution Patterns of Fiddler Crabs in a Tropical Mangrove Ecosystem

    PubMed Central

    Mokhtari, Mohammad; Ghaffar, Mazlan Abd; Usup, Gires; Cob, Zaidi Che

    2015-01-01

    In tropical regions, different species of fiddler crabs coexist on the mangrove floor, which sometimes makes it difficult to define species-specific habitat by visual inspection. The aim of this study is to find key environmental parameters which affect the distribution of fiddler crabs and to determine the habitats in which each species was most abundant. Crabs were collected from 19 sites within the mudflats of Sepang-Lukut mangrove forest. Temperature, porewater salinity, organic matter, water content, carbon and nitrogen content, porosity, chlorophyll content, pH, redox potential, sediment texture and heavy metals were determined in each 1 m2 quadrate. Pearson correlation indicated that all sediment properties except pH and redox potential were correlated with sediment grain size. Canonical correspondence analysis (CCA) indicated that Uca paradussumieri was negatively correlated with salinity and redox potential. Sand dwelling species, Uca perplexa and Uca annulipes, were highly dependent on the abundance of 250 μm and 150 μm grain size particles in the sediment. Canonical Discriminative Analysis (CDA) indicated that variation in sediment grain size best explained where each crab species was most abundant. Moreover, U. paradussumieri commonly occupies muddy substrates of low shore, while U. forcipata lives under the shade of mangrove trees. U. annulipes and U. perplexa with the high number of spoon tipped setae on their second maxiliped are specialized to feed on the sandy sediments. U. rosea and U. triangularis are more common on muddy sediment with high sediment density. In conclusion, sediment grain size that influences most sediment properties acts as a main factor responsible for sediment heterogeneity. In this paper, the correlation between fiddler crab species and environmental parameters, as well as the interaction between sediment characteristics, was explained in order to define the important environmental factors in fiddler crab distributions. PMID

  3. Determination of key environmental factors responsible for distribution patterns of fiddler crabs in a tropical mangrove ecosystem.

    PubMed

    Mokhtari, Mohammad; Ghaffar, Mazlan Abd; Usup, Gires; Cob, Zaidi Che

    2015-01-01

    In tropical regions, different species of fiddler crabs coexist on the mangrove floor, which sometimes makes it difficult to define species-specific habitat by visual inspection. The aim of this study is to find key environmental parameters which affect the distribution of fiddler crabs and to determine the habitats in which each species was most abundant. Crabs were collected from 19 sites within the mudflats of Sepang-Lukut mangrove forest. Temperature, porewater salinity, organic matter, water content, carbon and nitrogen content, porosity, chlorophyll content, pH, redox potential, sediment texture and heavy metals were determined in each 1 m2 quadrate. Pearson correlation indicated that all sediment properties except pH and redox potential were correlated with sediment grain size. Canonical correspondence analysis (CCA) indicated that Uca paradussumieri was negatively correlated with salinity and redox potential. Sand dwelling species, Uca perplexa and Uca annulipes, were highly dependent on the abundance of 250 μm and 150 μm grain size particles in the sediment. Canonical Discriminative Analysis (CDA) indicated that variation in sediment grain size best explained where each crab species was most abundant. Moreover, U. paradussumieri commonly occupies muddy substrates of low shore, while U. forcipata lives under the shade of mangrove trees. U. annulipes and U. perplexa with the high number of spoon tipped setae on their second maxiliped are specialized to feed on the sandy sediments. U. rosea and U. triangularis are more common on muddy sediment with high sediment density. In conclusion, sediment grain size that influences most sediment properties acts as a main factor responsible for sediment heterogeneity. In this paper, the correlation between fiddler crab species and environmental parameters, as well as the interaction between sediment characteristics, was explained in order to define the important environmental factors in fiddler crab distributions. PMID

  4. Distribution of genes encoding virulence factors and molecular analysis of Shigella spp. isolated from patients with diarrhea in Kerman, Iran.

    PubMed

    Hosseini Nave, Hossein; Mansouri, Shahla; Emaneini, Mohammad; Moradi, Mohammad

    2016-03-01

    Shigella is one of the important causes of diarrhea worldwide. Shigella has several virulence factors contributing in colonization and invasion of epithelial cells and eventually death of host cells. The present study was performed in order to investigate the distribution of virulence factors genes in Shigella spp. isolated from patients with acute diarrhea in Kerman, Iran as well as the genetic relationship of these isolates. A total of 56 isolates including 31 S. flexneri, 18 S. sonnei and 7 S. boydii were evaluated by polymerase chain reaction (PCR) for the presence of 11 virulence genes (ipaH, ial, set1A, set1B, sen, virF, invE, sat, sigA, pic and sepA). Then, the clonal relationship of these strains was analyzed by multilocus variable-number tandem repeat analysis (MLVA) method. All isolates were positive for ipaH gene. The other genes include ial, invE and virF were found in 80.4%, 60.7% and 67.9% of the isolates, respectively. Both set1A and set1B were detected in 32.3% of S. flexneri isolates, whereas 66.1% of the isolates belonging to different serogroup carried sen gene. The sat gene was present in all S. flexneri isolates, but not in the S. sonnei and S. boydii isolates. The result showed, 30.4% of isolates were simultaneously positive and the rest of the isolates were negative for sepA and pic genes. The Shigella isolates were divided into 29 MLVA types. This study, for the first time, investigated distribution of 11 virulence genes in Shigella spp. Our results revealed heterogeneity of virulence genes in different Shigella serogroups. Furthermore, the strains belonging to the same species had little diversity. PMID:26654792

  5. Factors controlling the spatial distribution of soil piping erosion on loess-derived soils: A case study from central Belgium

    NASA Astrophysics Data System (ADS)

    Verachtert, E.; Van Den Eeckhaut, M.; Poesen, J.; Deckers, J.

    2010-06-01

    Collapsible loess-derived soils are prone to soil piping erosion, where enlargement of macropores may lead to a subsurface pipe network and eventually to soil collapse and gully development. This study aims at understanding the main factors controlling spatial patterns of piping in loess-derived soils under a temperate climate. To map the spatial distribution of piping and identify the environmental controls on its distribution, a regional survey was carried out in a 236 km 2 study area in the Flemish Ardennes (Belgium). Orthophotos taken at optimal field conditions (winter) were analyzed to detect piping in open landscapes and ground thruthing was systematically done through field surveys. In total, 137 parcels having 560 collapsed pipes were mapped. Dimensions of the sinkholes and local slope gradient were measured in the field and topographical variables were derived from LiDAR data. Land use plays an important role as 97% of the sites with piping are found under pasture. The probability of piping increases rapidly on hillslopes with gradients exceeding 8% and with a concave profile and plan curvature, enhancing subsurface flow concentration. The zones with soil profiles on shallow loess over a relatively thin layer of homogeneous blue massive clays (Aalbeke Member) are most prone to piping. Soil characteristics are of less importance to explain piping occurrence. Furthermore, the topographical threshold line indicating the critical slope gradient for a given contributing drainage area was determined. This threshold line (negative power relation) is similar to the threshold line for shallow gully initiation.

  6. Effects of biotic and abiotic factors on the distribution of trout and salmon along a longitudinal stream gradient

    USGS Publications Warehouse

    De La, Hoz, Franco, E. A.; Budy, P.

    2005-01-01

    We examined the influence of biotic and abiotic factors on the distribution, abundance, and condition of salmonid fishes along a stream gradient. We observed a longitudinal change in fish distribution with native cutthroat trout, Oncorhynchus clarki utah, and introduced brown trout, Salmo trutta, demonstrating a distinct pattern of allopatry. Cutthroat trout dominated high elevation reaches, while reaches at lower elevations were dominated by brown trout. A transition zone between these populations was associated with lower total trout abundance, consistent changes in temperature and discharge, and differences in dietary preference. Variation in cutthroat trout abundance was best explained by a model including the abundance of brown trout and diel temperature, whereas variation in brown trout abundance was best explained by a model including the abundance of cutthroat trout and discharge. These results suggest the potential for condition-mediated competition between the two species. The results from our study can aid biologists in prioritizing conservation activities and in developing robust management strategies for cutthroat trout. ?? Springer 2005.

  7. Effect of macronutrient enrichment on the size distribution, sorption, and bioconcentration factor of iron by coastal phytoplanktonic diatoms.

    PubMed

    Li, Shun-Xing; Zheng, Feng-Ying

    2011-09-01

    The influences of macronutrient enrichment on iron absorption, adsorption, and the bioconcentration factor (BCF) of iron by coastal diatoms were examined. In addition, the distribution of different iron size fractions in seawater in relation to two diatom species exposed to nutrient enrichment over an extended period (6 days for Thalassiosira weissflogii, and 4 days for Skeletonema costatum), was investigated. Iron concentrations were measured of seven size fractions: particles (>0.4 μm), colloidal particles (0.4 μm-100, 100-50, 50-30, 30-10, 10-3 kDa), and soluble species (<3 kDa). The absorption, adsorption, uptake, BCF of iron by the diatoms, and the iron species distribution in seawater were affected by the diatom species, as well as the nitrate (N) and phosphate (P) concentration. The addition of P could affect the iron internalization strategy. The content of soluble iron species was positively correlated with the amount of iron absorption by T. weissflogii, but it was not suitable for S. costatum. PMID:21774978

  8. Chronic alcohol exposure differentially affects activation of female locus coeruleus neurons and the subcellular distribution of corticotropin releasing factor receptors

    PubMed Central

    Retson, T. A.; Reyes, B.A.; Van Bockstaele, E. J.

    2014-01-01

    Understanding the neurobiological bases for sex differences in alcohol dependence is needed to help guide the development of individualized therapies for alcohol abuse disorders. In the present study, alcohol-induced adaptations in (1) anxiety-like behavior, (2) patterns of c-Fos activation and (3) subcellular distribution of corticotropin releasing factor receptor in locus coeruleus (LC) neurons was investigated in male and female Sprague-Dawley rats that were chronically exposed to ethanol using a liquid diet. Results confirm and extend reports by others showing that chronic ethanol exposure produces an anxiogenic-like response in both male and female subjects. Ethanol-induced sex differences were observed with increased c-Fos expression in LC neurons of female ethanol-treated subjects compared to controls or male subjects. Results also reveal sex differences in the subcellular distribution of the CRFr in LC-noradrenergic neurons with female subjects exposed to ethanol exhibiting a higher frequency of plasmalemmal CRFrs. These adaptations have implications for LC neuronal activity and its neural targets across the sexes. Considering the important role of the LC in ethanol-induced activation of the hypothalamo-pituitary-adrenal (HPA) axis, the present results indicate important sex differences in feed-forward regulation of the HPA axis that may render alcohol dependent females more vulnerable to subsequent stress exposure. PMID:25149913

  9. Distribution of petroleum degrading genes and factor analysis of petroleum contaminated soil from the Dagang Oilfield, China

    PubMed Central

    Liu, Qinglong; Tang, Jingchun; Bai, Zhihui; Hecker, Markus; Giesy, John P.

    2015-01-01

    Genes that encode for enzymes that can degrade petroleum hydrocarbons (PHs) are critical for the ability of microorganisms to bioremediate soils contaminated with PHs. Distributions of two petroleum-degrading genes AlkB and Nah in soils collected from three zones of the Dagang Oilfield, Tianjin, China were investigated. Numbers of copies of AlkB ranged between 9.1 × 105 and 1.9 × 107 copies/g dry mass (dm) soil, and were positively correlated with total concentrations of PHs (TPH) (R2 = 0.573, p = 0.032) and alkanes (C33 ~ C40) (R2 = 0.914, p < 0.01). The Nah gene was distributed relatively evenly among sampling zones, ranging between 1.9 × 107 and 1.1 × 108 copies/g dm soil, and was negatively correlated with concentrations of total aromatic hydrocarbons (TAH) (R2 = −0.567, p = 0.035) and ∑16 PAHs (R2 = −0.599, p = 0.023). Results of a factor analysis showed that individual samples of soils were not ordinated as a function of the zones. PMID:26086670

  10. Distribution of petroleum degrading genes and factor analysis of petroleum contaminated soil from the Dagang Oilfield, China

    NASA Astrophysics Data System (ADS)

    Liu, Qinglong; Tang, Jingchun; Bai, Zhihui; Hecker, Markus; Giesy, John P.

    2015-06-01

    Genes that encode for enzymes that can degrade petroleum hydrocarbons (PHs) are critical for the ability of microorganisms to bioremediate soils contaminated with PHs. Distributions of two petroleum-degrading genes AlkB and Nah in soils collected from three zones of the Dagang Oilfield, Tianjin, China were investigated. Numbers of copies of AlkB ranged between 9.1 × 105 and 1.9 × 107 copies/g dry mass (dm) soil, and were positively correlated with total concentrations of PHs (TPH) (R2 = 0.573, p = 0.032) and alkanes (C33 ~ C40) (R2 = 0.914, p < 0.01). The Nah gene was distributed relatively evenly among sampling zones, ranging between 1.9 × 107 and 1.1 × 108 copies/g dm soil, and was negatively correlated with concentrations of total aromatic hydrocarbons (TAH) (R2 = -0.567, p = 0.035) and ∑16 PAHs (R2 = -0.599, p = 0.023). Results of a factor analysis showed that individual samples of soils were not ordinated as a function of the zones.

  11. The inter-annual distribution of cloudless days and nights in Abastumani: Coupling with cosmic factors and climate change

    NASA Astrophysics Data System (ADS)

    Didebulidze, G. G.; Todua, M.

    2016-04-01

    We examined inter-annual variations and long-term trends of cloudless days (CD) and cloudless nights (CN) in 1957-1993 from Abastumani (41.75N, 42.82E), at different geomagnetic conditions and corresponding galactic cosmic rays (GCRs) flux changes. It showed possible influence of cosmic factors on cloud covering processes and, thus, climate change. It was demonstrated that (1) the inter-annual distribution of monthly mean values of planetary geomagnetic index Ap (for low and moderate disturbances) at CDs can be described by harmonic function with semiannual (with sharp maxima in March and September) and annual (with maximum in August) periodicities; (2) the inter-annual distribution of Ap index for CN has an additional maximum in June, where the largest decrease of GCR flux is observed. This phenomenon is expressed even stronger during Sudden Storm Commencement (SSC) events and strong geomagnetic disturbances (Ap≥50), when their relative numbers are the greatest and are accompanied by bigger reduction of GCRs flux; (3) the long-term trends of mean annual and mean seasonal values of Ap index and GCRs flux at CD and CN are estimated. It was detected that, for the latitudes of this region, long-term decreases (negative trends) of seasonal GCR flux are different at CD and CN, which could affect the radiative balance at the Earth's surface and, as a result, contribute to the climate change.

  12. Distribution of ciliates in relation to environmental factors along the coastline of the Gulf of Gabes, Tunisia

    NASA Astrophysics Data System (ADS)

    Kchaou, Nouha; Elloumi, Jannet; Drira, Zaher; Hamza, Asma; Ayadi, Habib; Bouain, Abderrahmen; Aleya, Lotfi

    2009-08-01

    We studied the seasonal distribution of the ciliate community coupled with environmental factors along the coast at three stations sampled (from March 2006 to February 2007) in the Gulf of Gabes (Tunisia, Eastern Mediterranean Sea). A total of 56 species belonging to 11 orders, were identified. Harbor of Gabes station was more diversified (45 species) than both Tabia (26 species) and Karboub (31 species) stations. The ciliate assemblage was numerically dominated by Spirotrichea in Tabia (82% of the total abundance), in the Harbor of Gabes (86% of the total abundance), whereas, in Karboub, Spirotrichea represented only 40% of the total abundance. The unexpected lower quantitative importance of Spirotrichea in Karboub station was apparently the result of the high salt concentration found in water samples throughout the study, probably originating from the saline area surrounding Karboub station, known as Sabkha. The distribution of species in the nearshore of the Gulf of Gabes seemed most likely influenced by the combined effects of temperature, salinity and hydrographic conditions.

  13. Selectivity in glycosaminoglycan binding dictates the distribution and diffusion of fibroblast growth factors in the pericellular matrix

    PubMed Central

    Marcello, Marco

    2016-01-01

    The range of biological outcomes generated by many signalling proteins in development and homeostasis is increased by their interactions with glycosaminoglycans, particularly heparan sulfate (HS). This interaction controls the localization and movement of these signalling proteins, but whether such control depends on the specificity of the interactions is not known. We used five fibroblast growth factors with an N-terminal HaloTag (Halo-FGFs) for fluorescent labelling, with well-characterized and distinct HS-binding properties, and measured their binding and diffusion in pericellular matrix of fixed rat mammary 27 fibroblasts. Halo-FGF1, Halo-FGF2 and Halo-FGF6 bound to HS, whereas Halo-FGF10 also interacted with chondroitin sulfate/dermatan sulfate, and FGF20 did not bind detectably. The distribution of bound FGFs in the pericellular matrix was not homogeneous, and for FGF10 exhibited striking clusters. Fluorescence recovery after photobleaching showed that FGF2 and FGF6 diffused faster, whereas FGF1 diffused more slowly, and FGF10 was immobile. The results demonstrate that the specificity of the interactions of proteins with glycosaminoglycans controls their binding and diffusion. Moreover, cells regulate the spatial distribution of different protein-binding sites in glycosaminoglycans independently of each other, implying that the extracellular matrix has long-range structure. PMID:27009190

  14. A statistical evaluation of the safety factor and species sensitivity distribution approaches to deriving environmental quality guidelines.

    PubMed

    Zajdlik, Barry Alan

    2016-04-01

    The species sensitivity distribution (SSD) distribution approach to estimating water quality guidelines (WQGs) is the preferred method in all jurisdictions reviewed (Australia, Canada, New Zealand, Organisation for Economic Co-operation and Development [OECD] members, South Africa, United States) and is one of the recommended methods for European Commission members for 33 priority and priority hazardous substances. In the event that jurisdiction-specific criteria for data quality, quantity, and taxonomic representation are not met, all of these jurisdictions endorse the use of additional safety factors (SFs) applied to either the SSD-based WQG or, the lowest suitable toxicity test endpoint. In Canada, the British Columbia Ministry of Environment endorses this latter approach as the preferred approach in the belief that so-derived WQGs are more protective than SSD-based WQGs. The level of protection afforded by the latter SF approach was evaluated by statistically sampling minima from random samples of the following distributions: normal, Gumbel, logistic, and Weibull, using a range of coefficients of variation (cVs) and applying the SFs of 2 or 10 used in British Columbia. The simulations indicate that the potentially affected fraction of species (PAF) can be as high as 20%, or, approach 0%. The PAF varies with sample size and CV. Because CVs can vary systematically with mode of toxic action, the PAF using SF-based WQGs can also vary systematically with analyte class. The varying levels of protection afforded by SF-based WQGs are generally inconsistent with the common water quality management goal that allows for a small degree of change under long-term exposure. The findings suggest that further efforts be made to develop high-quality WQGs that support informed decision making and are consistent with the environmental management goal instead of using SFs in the hope of achieving an acceptable but unknown, degree of environmental protection. PMID:26272692

  15. Epidemiology, risk factor, species distribution, antifungal resistance and outcome of Candidemia at a single French hospital: a 7-year study.

    PubMed

    Tadec, Laurent; Talarmin, Jean-Philippe; Gastinne, Thomas; Bretonnière, Cédric; Miegeville, Michel; Le Pape, Patrice; Morio, Florent

    2016-05-01

    Candidemia remains a major cause of disease worldwide and is associated with a high mortality rate. We conducted a retrospective study of candidemia at Nantes Hospital, France, between 2004 and 2010. A total of 191 episodes (n = 188 patients) were reviewed. Incidence, demographics, risk factors, antifungal management, species identification, in vitro susceptibility and 12 weeks survival were analysed. Global incidence of candidemia was 0.37‰ admissions. Higher incidences were observed in haematology (6.65‰) and intensive care units (2‰). Central venous catheter and antibiotic exposure were the most frequent risk factors (77% and 76% respectively). Candida albicans was the predominant species (51.8%) followed by C. parapsilosis (14.5%), C. glabrata (9.8%), C. tropicalis (9.8%) and C. krusei (4.1%). However, species distribution differed significantly between medical units with frequency of C. tropicalis being higher in haematology compared to other medical units. Fluconazole and caspofungin were the main antifungals given as first-line therapy. Although not significant, 12 weeks mortality rate was 30.9%, being higher for C. tropicalis (44.4%) than for C. parapsilosis (16%). Acquired azole or echinocandin resistance was noted in some isolates, underlining the need for systematic antifungal susceptibility testing in patients with candidemia. These epidemiological findings will be of interest for antifungal stewardship at our hospital. PMID:26806101

  16. Factorization theorem for Drell-Yan at low q T and transverse-momentum distributions on-the-light-cone

    NASA Astrophysics Data System (ADS)

    Echevarría, Miguel G.; Idilbi, Ahmad; Scimemi, Ignazio

    2012-07-01

    We derive a factorization theorem for Drell-Yan process at low q T using effective field theory methods. In this theorem all the obtained quantities are gauge invariant and the special role of the soft function — and its subtraction thereof — is emphasized. We define transverse-momentum dependent parton distribution functions (TMDPDFs) which are free from light-cone singularities while all the Wilson lines are defined on-the-light-cone. We show explicitly to first order in α s that the partonic Feynman PDF can be obtained from the newly defined partonic TMDPDF by integrating over the transverse momentum of the parton inside the hadron. We obtain a resummed expression for the TMDPDF, and hence for the cross section, in impact parameter space. The universality of the newly defined matrix elements is established perturbatively to first order in α s . The factorization theorem is validated to first order in α s and also the gauge invariance between Feynman and light-cone gauges.

  17. Epidemiological features and risk factors associated with the spatial and temporal distribution of human brucellosis in China

    PubMed Central

    2013-01-01

    Background Human brucellosis incidence in China has been increasing dramatically since 1999. However, epidemiological features and potential factors underlying the re-emergence of the disease remain less understood. Methods Data on human and animal brucellosis cases at the county scale were collected for the year 2004 to 2010. Also collected were environmental and socioeconomic variables. Epidemiological features including spatial and temporal patterns of the disease were characterized, and the potential factors related to the spatial heterogeneity and the temporal trend of were analysed using Poisson regression analysis, Granger causality analysis, and autoregressive distributed lag (ADL) models, respectively. Results The epidemic showed a significantly higher spatial correlation with the number of sheep and goats than swine and cattle. The disease was most prevalent in grassland areas with elevation between 800–1,600 meters. The ADL models revealed that local epidemics were correlated with comparatively lower temperatures and less sunshine in winter and spring, with a 1–7 month lag before the epidemic peak in May. Conclusions Our findings indicate that human brucellosis tended to occur most commonly in grasslands at moderate elevation where sheep and goats were the predominant livestock, and in years with cooler winter and spring or less sunshine. PMID:24238301

  18. Play-level distributions of estimates of recovery factors for a miscible carbon dioxide enhanced oil recovery method used in oil reservoirs in the conterminous United States

    USGS Publications Warehouse

    Attanasi, E.D.; Freeman, P.A.

    2016-01-01

    The retention factor is the percentage of injected CO2 that is naturally retained in the reservoir. Retention factors were also estimated in this study. For clastic reservoirs, 90 percent of the estimated retention factors were between 21.7 and 32.1 percent, and for carbonate reservoirs, 90 percent were between 23.7 and 38.2 percent. The respective median values were 22.9 for clastic reservoirs and 26.1 for carbonate reservoirs. Both distributions were right skewed. The recovery and retention factors that were calculated are consistent with the corresponding factors reported in the literature.

  19. Magnetic-Activated Cell Sorting of TCR-Engineered T Cells, Using tCD34 as a Gene Marker, but Not Peptide–MHC Multimers, Results in Significant Numbers of Functional CD4+ and CD8+ T Cells

    PubMed Central

    Govers, Coen; Berrevoets, Cor; Treffers-Westerlaken, Elike; Broertjes, Marieke

    2012-01-01

    Abstract T cell-sorting technologies with peptide–MHC multimers or antibodies against gene markers enable enrichment of antigen-specific T cells and are expected to enhance the therapeutic efficacy of clinical T cell therapy. However, a direct comparison between sorting reagents for their ability to enrich T cells is lacking. Here, we compared the in vitro properties of primary human T cells gene-engineered with gp100280–288/HLA-A2-specific T cell receptor-αβ (TCRαβ) on magnetic-activated cell sorting (MACS) with various peptide–MHC multimers or an antibody against truncated CD34 (tCD34). With respect to peptide–MHC multimers, we observed that Streptamer®, when compared with pentamers and tetramers, improved T cell yield as well as level and stability of enrichment, of TCR-engineered T cells (>65% of peptide–MHC-binding T cells, stable for at least 6 weeks). In agreement with these findings, Streptamer, the only detachable reagent, revealed significant T cell expansion in the first week after MACS. Sorting TCR and tCD34 gene-engineered T cells with CD34 monoclonal antibody (mAb) resulted in the most significant T cell yield and enrichment of T cells (>95% of tCD34 T cells, stable for at least 6 weeks). Notably, T cells sorted with CD34 mAb, when compared with Streptamer, bound about 2- to 3-fold less peptide–MHC but showed superior antigen-specific upregulated expression of CD107a and production of interferon (IFN)-γ. Multiparametric flow cytometry revealed that CD4+ T cells, uniquely present in CD34 mAb-sorted T cells, contributed to enhanced IFN-γ production. Taken together, we postulate that CD34 mAb-based sorting of gene-marked T cells has benefits toward applications of T cell therapy, especially those that require CD4+ T cells. PMID:22871260

  20. Emission Factors, Size Distributions and Emission Inventories of Carbonaceous Particulate Matter from Residential Wood Combustion in Rural China

    PubMed Central

    Shen, Guofeng; Wei, Siye; Wei, Wen; Zhang, Yanyan; Min, Yujia; Wang, Bin; Wang, Rong; Li, Wei; Shen, Huizhong; Huang, Ye; Huang, Ye; Yang, Yifeng; Wang, Wei; Wang, Xilong; Wang, Xuejun; Tao, Shu

    2012-01-01

    Published emission factors (EFs) often vary significantly, leading to high uncertainties in emission estimations. There are few reliable EFs from field measurements of residential wood combustion in China. In this study, 17 wood fuels and one bamboo were combusted in a typical residential stove in rural China to measure realistic EFs of particulate matter (PM), organic carbon (OC) and elemental carbon (EC), as well as to investigate the influence of fuel properties and combustion conditions on the EFs. Measured EFs of PM, OC, and EC (EFPM, EFOC, and EFEC, respectively) were in the range of 0.38~6.4, 0.024~3.0 and 0.039~3.9 g/kg (dry basis), with means and standard derivation of 2.2±1.2, 0.62±0.64 and 0.83±0.69 g/kg, respectively. Shrubby biomass combustion produced higher EFs than tree woods, and both species had lower EFs than those of indoor crop residue burning (p<0.05). Significant correlations between EFPM, EFOC and EFEC were expected. By using a nine-stage cascade impactor, it was shown that size distributions of PM emitted from tree biomass combustions were unimodal with peaks at a diameter less than 0.4 µm (PM0.4), much finer than the PM from indoor crop residue burning. Approximately 79.4% of the total PM from tree wood combustion was PM with a diameter less than 2.1µm (PM2.1). PM size distributions for shrubby biomasses were slightly different from those for tree fuels. Based on the measured EFs, total emissions of PM, OC, and EC from residential wood combustion in rural China in 2007 were estimated at about 303, 75.7, and 92.0 Gg. PMID:22380753

  1. Emission factors, size distributions, and emission inventories of carbonaceous particulate matter from residential wood combustion in rural China.

    PubMed

    Guofeng, Shen; Siye, Wei; Wen, Wei; Yanyan, Zhang; Yujia, Min; Bin, Wang; Rong, Wang; Wei, Li; Huizhong, Shen; Ye, Huang; Yifeng, Yang; Wei, Wang; Xilong, Wang; Xuejun, Wang; Shu, Tao

    2012-04-01

    Published emission factors (EFs) often vary significantly, leading to high uncertainties in emission estimations. There are few reliable EFs from field measurements of residential wood combustion in China. In this study, 17 wood fuels and one bamboo were combusted in a typical residential stove in rural China to measure realistic EFs of particulate matter (PM), organic carbon (OC), and elemental carbon (EC), as well as to investigate the influence of fuel properties and combustion conditions on the EFs. Measured EFs of PM, OC, and EC (EF(PM), EF(OC), and EF(EC), respectively) were in the range of 0.38-6.4, 0.024-3.0, and 0.039-3.9 g/kg (dry basis), with means and standard derivation of 2.2 ± 1.2, 0.62 ± 0.64, and 0.83 ± 0.69 g/kg, respectively. Shrubby biomass combustion produced higher EFs than tree woods, and both species had lower EFs than those of indoor crop residue burning (p < 0.05). Significant correlations between EF(PM), EF(OC), and EF(EC) were expected. By using a nine-stage cascade impactor, it was shown that size distributions of PM emitted from tree biomass combustions were unimodal with peaks at a diameter less than 0.4 μm (PM(0.4)), much finer than the PM from indoor crop residue burning. Approximately 79.4% of the total PM from tree wood combustion was PM with a diameter less than 2.1 μm (PM(2.1)). PM size distributions for shrubby biomasses were slightly different from those for tree fuels. On the basis of the measured EFs, total emissions of PM, OC, and EC from residential wood combustion in rural China in 2007 were estimated at about 303, 75.7, and 92.0 Gg. PMID:22380753

  2. Diversity and distribution of transcription factors: their partner domains play an important role in regulatory plasticity in bacteria.

    PubMed

    Rivera-Gómez, Nancy; Segovia, Lorenzo; Pérez-Rueda, Ernesto

    2011-08-01

    The ability of bacteria to deal with diverse environmental changes depends on their repertoire of genes and their ability to regulate their expression. In this process, DNA-binding transcription factors (TFs) have a fundamental role because they affect gene expression positively and/or negatively depending on operator context and ligand-binding status. Here, we show an exhaustive analysis of winged helix-turn-helix domains (wHTHs), a class of DNA-binding TFs. These proteins were identified in high proportions and widely distributed in bacteria, representing around half of the total TFs identified so far. In addition, we evaluated the repertoire of wHTHs in terms of their partner domains (PaDos), identifying a similar trend, as with TFs, i.e. they are abundant and widely distributed in bacteria. Based on the PaDos, we defined three main groups of families: (i) monolithic, those families with little PaDo diversity, such as LysR; (ii) promiscuous, those families with a high PaDo diversity; and (iii) monodomain, with families of small sizes, such as MarR. These findings suggest that PaDos have a very important role in the diversification of regulatory responses in bacteria, probably contributing to their regulatory complexity. Thus, the TFs discriminate over longer regions on the DNA through their diverse DNA-binding domains. On the other hand, the PaDos would allow a great flexibility for transcriptional regulation due to their ability to sense diverse stimuli through a variety of ligand-binding compounds. PMID:21636649

  3. First Principles Calculation on Equilibrium Si Isotope Fractionation Factors and its Implementation on Si Isotope Distributions in Earth Surface Environments

    NASA Astrophysics Data System (ADS)

    Liu, Y.; He, H. T.; Zhu, C.

    2014-12-01

    Several important equilibrium Si isotope fractionation factors are calculated here. We use a so-called volume-variable-cluster-model (VVCM) method for solids and the "water-droplet" method for aqueous species for isotope fractionation calculation at the same quantum chemistry level. The calculation results show that several silicate minerals, such as quartz, feldspar, kaolinite, etc., all enrich heavy Si isotopes relative to aqueous H4SiO4 and can be up to 3.3‰ at 25°C, different from most field observations. Meanwhile stable organosilicon complexes can enrich even lighter Si isotopes than aqueous H4SiO4. For explaining the difference between the calculation results and field observations, we calculate the kinetic isotope effect (KIE) associated with the formation of amorphous silica, and find that amorphous silica will enrich extremely light Si isotopes. From amorphous silica to crystalline quartz, the structural adjustment & transition needs getting rid of small amount of Si to re-organize the structure. Light Si isotopes will be preferentially lost and let the final crystalline quartz with a little bit more heavy Si isotopes. However, such late-stage Si heavy isotope enrichment cannot erase the total isotopic signal, crystalline quartz still inherit much light Si isotopic composition from amorphous quartz. That is the reason for the discrepancy between the calculation results and the field observations, because the formation of amorphous quartz is under a non-equilibrium process but theoretical calculations are for equilibrium isotope fractionations. With accurate equilibrium fractionation factors provided here, Si isotope distributions in earth surface environments including soil, groundwater and plants can be further interpreted. We find that δ30Si variations in soil are mainly driven by secondary minerals precipitation and adsorption. Also, bulk soil δ30Si maybe have a parabolic distribution with soil age, with a minimum value at where allophane is

  4. Growth factor controls on the distribution and carbon isotope composition of n-alkanes in leaf wax

    NASA Astrophysics Data System (ADS)

    Jia, C.; Xie, S.; Huang, X.

    2012-12-01

    Cuticular wax plays pivotal physiological and ecological roles in the interactions between plants and the environments in which they grow. Plant-derived long-chain alkanes are more resistant to decay than other biochemical polymers. n-Alkane distributions (Carbon Preference Index (CPI) values and Average Chain Length (ACL) values) and carbon isotopic values are used widely in palaeoenvironmental reconstruction. However, there is little information available on how growth stages of the plant might influence the abundance of n-alkanes in the natural environment. In this study, we analyzed n-alkane distributions and carbon isotope data from two tree species (Cinnamomum camphora (L.) Presl. and Liquidambar formosana Hance) collected monthly from 2009 to 2011 in Nanwang Shan, Wuhan, Hubei Province. CPI values for n-alkanes from C. camphora remained stable in autumn and winter but fluctuated dramatically during spring and autumn each year. Positive correlations between CPI values and the relative content of (C27+C29) were observed in both sun and shade leaves of C. camphora from April to July. In L. formosana, CPI values decreased gradually from April to December. A similar trend was observed in all three years suggesting that growth stages rather than temperature or relative humidity affected the CPI values on a seasonal timescale. In the samples of L. formosana ACL values were negatively correlated with CPI values in the growing season (from April to July) and positively correlated with CPI values in the other seasons. The δ13C values of C29 and C31 n-alkanes displayed more negative carbon isotopic values in autumn and winter compared with leaves sampled at the start of the growing season from both trees. The δ13C values of C29 and C31 n-alkanes of L. formosana decreased from April to December. These results demonstrate the importance of elucidating the growing factors that influence the distribution and δ13C values of alkanes in modern leaves prior to using CPI

  5. Wet and dry deposition of mineral dust particles in Japan: factors related to temporal variation and spatial distribution

    NASA Astrophysics Data System (ADS)

    Osada, K.; Ura, S.; Kagawa, M.; Mikami, M.; Tanaka, T. Y.; Matoba, S.; Aoki, K.; Shinoda, M.; Kurosaki, Y.; Hayashi, M.; Shimizu, A.; Uematsu, M.

    2014-01-01

    of the sum of > 20 μm and 10-20 μm (giant fraction) were higher than 50% for most of the event samples. Irrespective of the deposition type, the giant dust fractions generally decreased with increasing distance from the source area, suggesting the selective depletion of larger giant particles during atmospheric transport. Based on temporal variations of PMc (2.5 < D < 10 μm), ground-based lidar, backward air trajectories, and vertical profiles of potential temperatures, transport processes of dust particles are discussed for events with high-deposition and low-deposition flux with high PMc. Low dry dust depositions with high PMc concentrations were observed under stronger (5 K km-1) stratification of potential temperature with thinner and lower (< 2 km) dust distributions because the PMc fraction of dust particles only survived after depletion of giant dust particles by rapid gravitational settling at the time they reach Japan. In contrast, transport through a thicker (> 2 km) dust layer with weak vertical gradient of potential temperature carry more giant dust particles to Japan. Because giant dust particles are an important mass fraction of dust accumulation, especially in the North Pacific, which is known as a high-nutrient, low-chlorophyll (HNLC) region, the transport height and fraction of giant dust particles are important factors for studying dust budgets in the atmosphere and their role in biogeochemical cycles.

  6. Astrocyte-Secreted Factors Modulate the Developmental Distribution of Inhibitory Synapses in Nucleus Laminaris of the Avian Auditory Brainstem

    PubMed Central

    Korn, Matthew J.; Koppel, Scott J.; Li, Lan H.; Mehta, Divya; Mehta, Sonia B.; Seidl, Armin H.; Cramer, Karina S.

    2014-01-01

    Nucleus laminaris (NL) neurons in the avian auditory brainstem are coincidence detectors necessary for the computation of interaural time differences used in sound localization. In addition to their excitatory inputs from nucleus magnocellularis, NL neurons receive inhibitory inputs from the superior olivary nucleus (SON) that greatly improve coincidence detection in mature animals. The mechanisms that establish mature distributions of inhibitory inputs to NL are not known. We used the vesicular GABA transporter (VGAT) as a marker for inhibitory presynaptic terminals to study the development of inhibitory inputs to NL between embryonic day 9 (E9) and E17. VGAT immunofluorescent puncta were first seen sparsely in NL at E9. The density of VGAT puncta increased with development, first within the ventral NL neuropil region and subsequently throughout both the ventral and dorsal dendritic neuropil, with significantly fewer terminals in the cell body region. A large increase in density occurred between E13–15 and E16–17, at a developmental stage when astrocytes that express glial fibrillary acidic protein (GFAP) become mature. We cultured E13 brainstem slices together with astrocyte-conditioned medium (ACM) obtained from E16 brainstems and found that ACM, but not control medium, increased the density of VGAT puncta. This increase was similar to that observed during normal development. Astrocyte-secreted factors interact with the terminal ends of SON axons to increase the number of GABAergic terminals. These data suggest that factors secreted from GFAP-positive astrocytes promote maturation of inhibitory pathways in the auditory brainstem. PMID:22020566

  7. Factors influencing the number distribution and size of the particles emitted from a modern diesel vehicle in real urban traffic

    NASA Astrophysics Data System (ADS)

    Barrios, C. C.; Domínguez-Sáez, A.; Rubio, J. R.; Pujadas, M.

    2012-09-01

    Particle emissions from diesel engine cars depend firstly on exhaust aftertreatment systems but the use of the vehicle becomes also crucial. In urban areas, this use depends on: transport demand, route choices, traffic density, street conditions, weather, driver behaviour and topographical characteristics of the roads. Nowadays, most diesel vehicles in urban areas across Europe are equipped with exhaust aftertreatment systems aiming to reduce the total mass of emitted particles. In comparison to earlier aftertreatment systems, the implementation of modern procedures is causing a reduction in the size of the emitted particles up to a nanometric range. The main goal of this work is the characterization of particle size and number distribution in the submicrometric range from a modern diesel vehicle emission in real traffic conditions in the city of Madrid with the purpose of assessing the actual weight of the different city parameters influencing the particle emission. In order to accomplish this objective, up to 12 on board emission measurement experiments have been performed with a Euro IV Diesel passenger car driving along a single urban circuit in Madrid City. To cover the main external factors, stretch, traffic conditions and driving directions have been considered as independent variables for this study. Assuming a proper car operating conditions, the results show that street characteristics, vehicle density and topographic features are the main factors conditioning the particle emission. Extrapolating our results, a diesel standard passenger car circulating across a city like Madrid can emit more nanoparticles per kilometre (up to 114% more in this study) at peak hour than at off peak hour. Moreover, the driving direction can also influence dramatically the emission of nanoparticles per second. This difference in the emission rate depends on the street but in our study it can be higher than 110% depending on the driving direction.

  8. Phylogeographic concordance factors quantify phylogeographic congruence among co-distributed species in the Sarracenia alata pitcher plant system.

    PubMed

    Satler, Jordan D; Carstens, Bryan C

    2016-05-01

    Comparative phylogeographic investigations have identified congruent phylogeographic breaks in co-distributed species in nearly every region of the world. The qualitative assessments of phylogeographic patterns traditionally used to identify such breaks, however, are limited because they rely on identifying monophyletic groups across species and do not account for coalescent stochasticity. Only long-standing phylogeographic breaks are likely to be obvious; many species could have had a concerted response to more recent landscape events, yet possess subtle signs of phylogeographic congruence because ancestral polymorphism has not completely sorted. Here, we introduce Phylogeographic Concordance Factors (PCFs), a novel method for quantifying phylogeographic congruence across species. We apply this method to the Sarracenia alata pitcher plant system, a carnivorous plant with a diverse array of commensal organisms. We explore whether a group of ecologically associated arthropods have co-diversified with the host pitcher plant, and identify if there is a positive correlation between ecological interaction and PCFs. Results demonstrate that multiple arthropods share congruent phylogeographic breaks with S. alata, and provide evidence that the level of ecological association can be used to predict the degree of similarity in the phylogeographic pattern. This study outlines an approach for quantifying phylogeographic congruence, a central concept in biogeographic research. PMID:27076412

  9. Revealing the influence of various factors on concentration and spatial distribution of suspended matter based on remote sensing data

    NASA Astrophysics Data System (ADS)

    Lavrova, Olga Y.; Soloviev, Dmitry M.; Mityagina, Marina I.; Strochkov, Alexey Y.; Bocharova, Tatiana Y.

    2015-10-01

    The paper discusses the results of a research on the influence of various hydrometeorological factors on distribution of suspended matter carried by rivers into the sea. The research is based on remote sensing data received in different bands of electromagnetic spectrum. Suspended matter concentration and integral water turbidity were estimated based on data from MODIS, MERIS, ETM+, TM and OLI sensors. The study was performed for two regions with very different characteristics: the semi-enclosed Gulf of Gdańsk of the Baltic Sea and eastern part of the Black Sea. It is shown that the plume fraction with highest suspended matter concentration of the lowland River Vistula spreads primarily under the impact of wind. Low concentration plume fraction is driven by the longshore current. In case of extraordinary floods, turbid Vistula waters spread in the upper sea layer almost all over the Gulf. The situation in the eastern part of the Black Sea with its narrow shoal and abrupt shelf edge wherein flow highly turbid mountain rivers is quite different. Here, the dominating role is played by runoff. Its intensity determines both plume shape and dimensions. A strong easterly wind can change plume configuration, cause formation of jet-like plumes.

  10. Prevalence of human papillomavirus (HPV), distribution of HPV types, and risk factors for infection in HPV-positive women.

    PubMed

    Santos Filho, M V C; Gurgel, A P A D; Lobo, C D P; Freitas, A C F; Silva-Neto, J C; Silva, L A F

    2016-01-01

    The aim of this study was to describe the prevalence of human papillomavirus (HPV), the distribution of different HPV types, and the putative risk factors for infection among HPV-positive women from the State of Alagoas, Northeast Brazil. We analyzed data from 515 patients attending public and private health centers. HPV DNA from cervical samples was extracted and HPV genotyping was performed by polymerase chain reaction using MY09/11 consensus primers followed by direct sequencing. The chi-squared test for independence was used to assess statistical differences between the HPV groups. HPV DNA was found in 111 (21.55%) cervical samples. Twenty genotypes were detected: HPV6, 11, 16, 31, 33, 35, 39, 52, 53, 54, 58, 61, 62, 66, 70, 72, 81, 82, 83, and 84. In addition, multiple sexual partners (P = 0.002) and the use of oral contraceptives (P = 0.015) were associated with the presence of HPV. These findings may be relevant to the design of screening and vaccination strategies targeting specific groups of women in Northeast Brazil. PMID:27421019

  11. Acquired von Willebrand syndrome: von Willebrand factor propeptide to von Willebrand factor antigen ratio predicts remission status

    PubMed Central

    Lee, Adrienne; Sinclair, Gary; Valentine, Karen; James, Paula

    2014-01-01

    We investigated a case of acquired von Willebrand syndrome (AVWS) secondary to a nonneutralizing anti-von Willebrand factor (VWF) antibody associated with an autoimmune disorder. At diagnosis, VWF activity (VWF:Act), antigen (VWF:Ag), multimers, and factor VIII coagulant activity were virtually absent. VWF propeptide (VWFpp) was elevated with an infinitely high VWFpp to VWF:Ag ratio (VWFpp:Ag) consistent with rapid VWF clearance. Immunosuppressive treatment resulted in phenotypic remission 1 with normalization of VWF/factor VIII levels and multimer pattern. However, VWFpp:Ag remained elevated (∼2× normal), consistent with ongoing VWF clearance by the remaining anti-VWF antibody still present by enzyme-linked immunosorbent assay. This suggests that increased VWF secretion was compensating for the incomplete remission state. Relapse occurred when VWFpp:Ag was again infinitely high, with associated decreased VWFpp but unchanged anti-VWF titers; switching the balance to favor VWF clearance over secretion. Complete remission with undetectable anti-VWF occurred only when VWFpp:Ag was normal. This case of relapsing-remitting AVWS demonstrates the use of VWFpp:Ag for predicting remission status. PMID:24951428

  12. A Finding Method of Business Risk Factors Using Characteristics of Probability Distributions of Effect Ratios on Qualitative and Quantitative Hybrid Simulation

    NASA Astrophysics Data System (ADS)

    Samejima, Masaki; Negoro, Keisuke; Mitsukuni, Koshichiro; Akiyoshi, Masanori

    We propose a finding method of business risk factors on qualitative and quantitative hybrid simulation in time series. Effect ratios of qualitative arcs in the hybrid simulation vary output values of the simulation, so we define effect ratios causing risk as business risk factors. Finding business risk factors in entire ranges of effect ratios is time-consuming. It is considered that probability distributions of effect ratios in present time step and ones in previous time step are similar, the probability distributions in present time step can be estimated. Our method finds business risk factors in only estimated ranges effectively. Experimental results show that a precision rate and a recall rate are 86%, and search time is decreased 20% at least.

  13. Microtubule-associated protein 2 (MAP2) in Purkinje cell dendrites: Evidence that factors other than binding to microtubules are involved in determining its cytoplasmic distribution

    SciTech Connect

    Matus, A.; Delhaye-Bouchaud, N.; Mariani, J. )

    1990-07-15

    We have studied the distribution of microtubule-associated protein 2 (MAP2) in the Purkinje cell dendrites of rats whose cerebella were exposed to X-irradiation during the second postnatal week. The Purkinje cells of such animals have abnormally elongated apical primary processes that branch in the other molecular layer rather than close to the cell body as in normal tissue. The results show that in these distorted dendrites the MAP2 distribution is shifted distally relative to the normal pattern, in which MAP2 is distributed evenly throughout the dendritic tree. Tubulin and other microtubule-associated proteins, such as MAP1, are not affected and remain evenly distributed throughout the dendritic tree despite the anatomical distortion. We conclude that the distribution of MAP2 in Purkinje cells is not determined solely by its binding to tubulin. Other factors must be involved and these appear to be related to dendritic morphology and possibly to branching.

  14. Characterization of concentration, particle size distribution, and contributing factors to ambient hexavalent chromium in an area with multiple emission sources

    NASA Astrophysics Data System (ADS)

    Yu, Chang Ho; Huang, Lihui; Shin, Jin Young; Artigas, Francisco; Fan, Zhi-hua (Tina)

    2014-09-01

    Airborne hexavalent chromium (Cr(VI)) is a known pulmonary carcinogen and can be emitted from both natural and anthropogenic sources, including diesel emissions. However, there is limited knowledge about ambient Cr(VI) concentration levels and its particle size distribution. This pilot study characterized ambient Cr(VI) concentrations in the New Jersey Meadowlands (NJ ML) district, which is close to the heavily trafficked New Jersey Turnpike (NJTPK) as well as Chromium Ore Processing Residue (COPR) waste sites. Monitoring was simultaneously conducted at two sites, William site (∼50 m from NJTPK) and MERI site (∼700 m from NJTPK). The distance between the two sites is approximately 6.2 km. Ambient Cr(VI) concentrations and PM2.5 mass concentrations were concurrently measured at both sites during summer and winter. The summer concentrations (mean ± S.D. [median]), 0.13 ± 0.06 [0.12] ng/m3 at the MERI site and 0.08 ± 0.05 [0.07] ng/m3 at the William site, were all significantly higher than the winter concentrations, 0.02 ± 0.01 [0.02] ng/m3 and 0.03 ± 0.01 [0.03] ng/m3 at the MERI and William sites, respectively. The site difference (i.e., MERI > William) was observed for summer Cr(VI) concentrations; however, no differences for winter and pooled datasets. These results suggest higher Cr(VI) concentrations may be attributed from stronger atmospheric reactions such as photo-oxidation of Cr(III) to Cr(VI) in the summer. The Cr(VI) distribution as a function of particle size, ranging from 0.18 to 18 μm, was determined at the William site. It was found that Cr(VI) was enriched in the particles less than 2.5 μm in diameter (PM2.5). This finding suggested potential health concerns, because PM2.5 are easily inhaled and deposited in the alveoli. A multiple linear regression analysis confirmed ambient Cr(VI) concentrations were significantly affected by meteorological factors (i.e., temperature and humidity) and reactive gases/particles (i.e., O3, Fe and Mn).

  15. Characterization of concentration, particle size distribution, and contributing factors to ambient hexavalent chromium in an area with multiple emission sources

    PubMed Central

    Yu, Chang Ho; Huang, Lihui; Shin, Jin Young; Artigas, Francisco; Fan, Zhi-hua (Tina)

    2015-01-01

    Airborne hexavalent chromium (Cr(VI)) is a known pulmonary carcinogen and can be emitted from both natural and anthropogenic sources, including diesel emissions. However, there is limited knowledge about ambient Cr(VI) concentration levels and its particle size distribution. This pilot study characterized ambient Cr(VI) concentrations in the New Jersey Meadowlands (NJ ML) district, which is close to the heavily trafficked New Jersey Turnpike (NJTPK) as well as Chromium Ore Processing Residue (COPR) waste sites. Monitoring was simultaneously conducted at two sites, William site (~50 m from NJTPK) and MERI site (~700 m from NJTPK). The distance between the two sites is approximately 6.2 km. Ambient Cr(VI) concentrations and PM2.5 mass concentrations were concurrently measured at both sites during summer and winter. The summer concentrations (mean ± S.D. [median]), 0.13 ± 0.06 [0.12] ng/m3 at the MERI site and 0.08 ± 0.05 [0.07] ng/m3 at the William site, were all significantly higher than the winter concentrations, 0.02 ± 0.01 [0.02] ng/m3 and 0.03 ± 0.01 [0.03] ng/m3 at the MERI and William sites, respectively. The site difference (i.e., MERI > William) was observed for summer Cr(VI) concentrations; however, no differences for winter and pooled datasets. These results suggest higher Cr(VI) concentrations may be attributed from stronger atmospheric reactions such as photo-oxidation of Cr(III) to Cr(VI) in the summer. The Cr(VI) distribution as a function of particle size, ranging from 0.18 to 18 μm, was determined at the William site. It was found that Cr(VI) was enriched in the particles less than 2.5 μm in diameter (PM2.5). This finding suggested potential health concerns, because PM2.5 are easily inhaled and deposited in the alveoli. A multiple linear regression analysis confirmed ambient Cr(VI) concentrations were significantly affected by meteorological factors (i.e., temperature and humidity) and reactive gases/particles (i.e., O3, Fe and Mn). PMID

  16. Cross-sectional study of brucellosis in Jordan: Prevalence, risk factors and spatial distribution in small ruminants and cattle.

    PubMed

    Musallam, I I; Abo-Shehada, M; Omar, M; Guitian, J

    2015-03-01

    Brucellosis is considered endemic in many Middle Eastern countries including Jordan. To determine the frequency, risk factors and spatial distribution of ruminant brucellosis in Jordan, a nationwide cross-sectional study was conducted. Small ruminant flocks (n=333) and cattle herds (n=204) were randomly selected, and their disease status was ascertained by testing individual serum samples using the Rose Bengal Test and a competitive ELISA (sheep and goats) and milk samples using an indirect ELISA (cattle). Information on putative risk factors was collected using standardized questionnaires. A logistic model with a binomial outcome was built to identify risk factors for being seropositive. The estimated true seroprevalence values were 18.1% (95% CI: 11-25.3) (cattle-only herds), 22.2% (95% CI: 16.5-28.8) (sheep flocks), 45.4% (95% CI: 30.3-61.6) (goat herds), 70.4% (95% CI: 55.5-84.9) (mixed sheep-goat flocks), 34.3% (95% CI: 28.4, 40.4) (all small ruminant flocks) and 38.5% (95% CI: 24.3-51.8) (mixed herds of cattle and small ruminants). Only 1.5% of small ruminant flocks were vaccinated. The seroprevalence was higher in northern areas, where livestock density is also higher. The logistic model fitted the data well and had a very high predictive ability. In the small ruminant model, five variables were significantly associated with a higher odds of seropositivity: lending/borrowing rams (OR=8.9, 95% CI: 3.0-26.1), feeding aborted material to dogs (OR=8.0, 95% CI: 3.5-18.1) the presence of goats (OR=6.9, 95% CI: 3.1-15.4), introducing new animals to the flock (OR=5.8, 95% CI: 2.5-13.6), and a large flock size (OR=2.2, 95% CI: 1.0-4.6). Conversely, separating newly introduced animals (OR=0.16, 95% CI: 0.05-0.47), separating animals that had aborted (OR=0.19, 95% CI: 0.08-0.46) and using disinfectants to clean pens (OR=0.37, 95% CI: 0.16-0.83) were significantly associated with a lower odds of being seropositive. The main risk factor for cattle herds being

  17. The relationship between fat distribution and coronary risk factors in sedentary postmenopausal women on and off hormone replacement therapy.

    PubMed

    Perry, A C; Allison, M; Applegate, E B; Jackson, M L; Miller, P C

    1998-01-01

    The purpose of this study was to examine the relationship between fat distribution and coronary risk factors (CRF) in sedentary overweight postmenopausal women both on and off hormone replacement therapy (HRT). Medical records and information were abstracted from nonsmoking women entering a weight loss program. A total of 33 women on HRT (mean age=50.12+/-5.2) and 51 nonusers (mean age=52.52+/-7.8) fulfilled subject eligibility requirements and were included in the data analysis. Results showed a significantly lower waist-to-hip ratio (WHR) (p=0.009) and waist (p=0.010) and greater levels of high-density lipoprotein cholesterol (HDL-C) (p=0.035) in HRT users than in nonusers. After converting correlations to standard Z-scores and performing z-tests, the correlation between total cholesterol (T-Chol) and WHR was significantly greater in nonusers than in HRT users (p=0.038). A multiple regression analysis showed differences between groups in the ability of age and anthropometric variables to predict CRF. Although T-Chol could be predicted in nonusers (r2=0.24; p=0.011), very low-density lipoprotein cholesterol (VLDL-C) and systolic blood pressure (SBP) could be significantly predicted in HRT users only (r2=0.28, p=0.055 and r2=0.40, p=0.005 for VLDL-C and SBP, respectively). These data suggest that there are differences between HRT users and nonusers in predictors of CRF, central adiposity, HDL-C, and the relationship between WHR and T-Chol. It is concluded that the significantly lower levels of central adiposity observed in HRT users may have clinical benefits with regard to CRF. PMID:9526969

  18. Trends in contraceptive use and distribution of births with demographic risk factors in Ethiopia: a sub-national analysis

    PubMed Central

    Shiferaw, Solomon; Abdullah, Muna; Mekonnen, Yared; Maïga, Abdoulaye; Akinyemi, Akanni; Amouzou, Agbessi; Friedman, Howard; Barros, Aluisio J. D.; Hounton, Sennen

    2015-01-01

    Background Evidence shows that family planning contributes to the decline in child mortality by decreasing the proportions of births that are considered high risk. The main objective of the present analysis was to examine the trends in use of modern contraceptives and their relationship with total fertility rate (TFR) and distribution of births by demographic risk factors as defined by mother's age, birth interval, and birth order at the sub-national level in Ethiopia. Design Analyses used data from three Demographic and Health Surveys in Ethiopia (2000, 2005, and 2011), which are nationally representative data collected through questionnaire-based interviews from women 15–49 using a stratified, two-stage cluster sampling. First, we examined the trends of and relationship between TFR (in the 3 years before each survey) and modern contraceptive use among currently married women in all administrative regions over the time period 2000–2011 using linear regression analysis. We also examined the relationship between birth risks and under-five mortality using the no-risk group as a reference. Finally, multiple logistic regression analysis was performed to estimate the relationship between the effect of being a resident in one of the regions and having an avoidable birth risk (which includes births to mothers younger than 18 and older than 34 years, birth interval of less than 24 months and birth order higher than third) after adjusting for select covariates including wealth, educational status, residence, religion and exposure to family planning information. Results Sub-national-level regression analysis showed an inverse relationship between modern contraceptive use among married women and the TFR, with an average decrease of TFR by one child per woman associated with a 13 percentage point increase in modern contraceptive use between 2000 and 2011. A high percentage of births in Ethiopia (62%) fall in one of the risk categories (excluding first births), with wide

  19. The Distribution of and Factors Associated with Intimate Terrorism and Situational Couple Violence among a Population-Based Sample of Urban Women in the United States

    ERIC Educational Resources Information Center

    Frye, Victoria; Manganello, Jennifer; Campbell, Jacquelyn C.; Walton-Moss, Benita; Wilt, Susan

    2006-01-01

    It has been proposed that two distinct forms of intimate partner violence exist: intimate terrorism and situational couple violence. This article describes the distribution of factors that characterize intimate terrorism and situational couple violence, including controlling behaviors, violence escalation, and injury, among a representative sample…

  20. Non-negative matrix factorization for the near real-time interpretation of absorption effects in elemental distribution images acquired by X-ray fluorescence imaging.

    PubMed

    Alfeld, Matthias; Wahabzada, Mirwaes; Bauckhage, Christian; Kersting, Kristian; Wellenreuther, Gerd; Barriobero-Vila, Pere; Requena, Guillermo; Boesenberg, Ulrike; Falkenberg, Gerald

    2016-03-01

    Elemental distribution images acquired by imaging X-ray fluorescence analysis can contain high degrees of redundancy and weakly discernible correlations. In this article near real-time non-negative matrix factorization (NMF) is described for the analysis of a number of data sets acquired from samples of a bi-modal α+β Ti-6Al-6V-2Sn alloy. NMF was used for the first time to reveal absorption artefacts in the elemental distribution images of the samples, where two phases of the alloy, namely α and β, were in superposition. The findings and interpretation of the NMF results were confirmed by Monte Carlo simulation of the layered alloy system. Furthermore, it is shown how the simultaneous factorization of several stacks of elemental distribution images provides uniform basis vectors and consequently simplifies the interpretation of the representation. PMID:26917147

  1. Factors determining growth and vertical distribution of planktonic algae in extremely acidic mining lakes (pH 2.7)

    NASA Astrophysics Data System (ADS)

    Bissinger, Vera

    2003-04-01

    In this thesis, I investigated the factors influencing the growth and vertical distribution of planktonic algae in extremely acidic mining lakes (pH 2-3). In the focal study site, Lake 111 (pH 2.7; Lusatia, Germany), the chrysophyte, Ochromonas sp., dominates in the upper water strata and the chlorophyte, Chlamydomonas sp., in the deeper strata, forming a pronounced deep chlorophyll maximum (DCM). Inorganic carbon (IC) limitation influenced the phototrophic growth of Chlamydomonas sp. in the upper water strata. Conversely, in deeper strata, light limited its phototrophic growth. When compared with published data for algae from neutral lakes, Chlamydomonas sp. from Lake 111 exhibited a lower maximum growth rate, an enhanced compensation point and higher dark respiration rates, suggesting higher metabolic costs due to the extreme physico-chemical conditions. The photosynthetic performance of Chlamydomonas sp. decreased in high-light-adapted cells when IC limited. In addition, the minimal phosphorus (P) cell quota was suggestive of a higher P requirement under IC limitation. Subsequently, it was shown that Chlamydomonas sp. was a mixotroph, able to enhance its growth rate by taking up dissolved organic carbon (DOC) via osmotrophy. Therefore, it could survive in deeper water strata where DOC concentrations were higher and light limited. However, neither IC limitation, P availability nor in situ DOC concentrations (bottom-up control) could fully explain the vertical distribution of Chlamydomonas sp. in Lake 111. Conversely, when a novel approach was adopted, the grazing influence of the phagotrophic phototroph, Ochromonas sp., was found to exert top-down control on its prey (Chlamydomonas sp.) reducing prey abundance in the upper water strata. This, coupled with the fact that Chlamydomonas sp. uses DOC for growth, leads to a pronounced accumulation of Chlamydomonas sp. cells at depth; an apparent DCM. Therefore, grazing appears to be the main factor influencing the

  2. Predicting probability of occurrence and factors affecting distribution and abundance of three Ozark endemic crayfish species at multiple spatial scales

    USGS Publications Warehouse

    Nolen, Matthew S.; Magoulick, Daniel D.; DiStefano, Robert J.; Imhoff, Emily M.; Wagner, Brian K.

    2014-01-01

    We found that a range of environmental variables were important in predicting crayfish distribution and abundance at multiple spatial scales and their importance was species-, response variable- and scale dependent. We would encourage others to examine the influence of spatial scale on species distribution and abundance patterns.

  3. Differential Effects of Economic Factors on Specialist and Family Physician Distribution in Illinois: A County-Level Analysis

    ERIC Educational Resources Information Center

    Mistretta, Martin J.

    2007-01-01

    Context: Uneven distribution of physicians across geographic areas of the United States remains a significant problem that may have implications for health. Purpose: To develop a statistical model of physician distribution in Illinois counties that predicts where specialists and family physicians practice, and to suggest policy strategies for…

  4. Rock avalanche occurrence in the San Juan province (Argentina): an analysis of their spatial distribution and main forcing factors

    NASA Astrophysics Data System (ADS)

    Penna, Ivanna; Tonini, Marj; Vega Orozco, Carmen D.; Longchamp, Céline; Derron, Marc-Henri; Jaboyedoff, Michel

    2013-04-01

    Rock avalanches are frequent phenomena in the Argentinean Andes and a particular high concentration of these events is observed in the Northwest (~25°S) and in the Central Andes from 30°S until the transition with the Patagonian Andes (~38°S). Tectonic deformation and seismicity are generally proposed as main driving factors, with weather and lithologic conditions playing a subordinate role. From 28°S to 33°S, the subhorizontal subduction of the Nazca plate drives higher shortening rates than in the surrounding areas, and an intense seismicity. Main morphotectonic units in this regions are the Cordillera and Precordillera, separated by the Barreal-Calingasta depression. In the southern central part of the flat subduction area (30°30'°-32°30'S), it is observed high valley incision and maximum local relief of 2900 m, while in the Precordillera main fluvial courses developed in the inter-thrust valleys, where local relief is up to 2400 m. In both mountain ranges, we recognized 34 rock avalanches deposits with volumes up to 0.3 km3. There is no apparent lithologic control on detachments, which involved sedimentary, volcanic and granite rocks, even though ~20% of them were favored by layering orientation. However, about 50% of the inventoried rock avalanches with the greatest volumes, developed along tectonic structures or less than 1 km far from them. The main objective of the present study is to explore the spatial distribution of rock avalanche deposits, and compare it with the instrumental seismicity and landscape conditions by means of statistical tools (e.g. exploratory data analyses, Ripley's K-function). Those analyses allow to highlight the spatial correlation between the geological events. Moreover, to visually display the detected cluster spatial patterns we elaborated kernel density maps. Our findings revealed that most of the rock avalanches show a high spatial aggregation mainly between 31°20'S-31°50'S. Main concentration of bedrock landslides

  5. [Distribution of PGEs contents and its factors in snowfall and snow cover over the arid region in Changji City].

    PubMed

    Liu, Yu-Yan; Liu, Hao-Feng; Zhang, Lan

    2013-02-01

    This paper was to select a small-medium sized City, Changji city, over the arid region, study the distribution of platinum group metals(PGEs) contents and influencing factors in snowfall and snow cover. Samples were analysed by ICP-MS. The results revealed that the annual contents of Rh, Pd and Pt in snowfall were on the average value of 0.43 ng.L-1 ranging from not detected to 2.24 ng.L-1 , 60.07 ng.L-1 ranging from 46.66 to 84.25 ng.L-1 and 4.54 ng.L-1 ranging from 3.02 ng.L-1 to 6.38 ng.L-1 respectively. The difference of PGEs levels was found in different occurrences of snowfall, tended to increase before snowfall due to the longer arid days. PGEs contents maybe influenced by the amount of snowfall, the less snowfall, the higher PGEs contents reflected. The annual levels of Rh, Pd and Pt in snow cover were in the range of 2.50-18.80 ng.L-1 (av. 6.65 ng.L-1), 46.83-199.20 ng.L-1 (av. 83.45 ng.L-1) ,4. 27-13.78 ng.L-1 (av. 8.17 ng.L-1) respectively. PGEs content in snow cover were far higher than that of snowfall, PGEs in snowfall were only obtained from atmospheric PGEs rinsed by single time of snowfall, while PGEs were not only from the accumulation of PGEs in frequent times of snowfall and the snow cover under the long time exposure, but also continuously accepted the PGEs from atmospheric dry deposition. PGEs content of snow cover in all sampling sites were demonstrated as follows: traffic area > residential-culture-education district > square of park > suburban farmland. the input way of PGEs in snow cover was found a remarkable difference with the amount of input within different function areas, which was the main reason caused that PGEs content of snow cover in each function area varied and had a certain regularity. PMID:23668114

  6. Observed effects of “distributional learning” may not relate to the number of peaks. A test of “dispersion” as a confounding factor

    PubMed Central

    Wanrooij, Karin; Boersma, Paul; Benders, Titia

    2015-01-01

    Distributional learning of speech sounds is learning from simply being exposed to frequency distributions of speech sounds in one’s surroundings. In laboratory settings, the mechanism has been reported to be discernible already after a few minutes of exposure, in both infants and adults. These “effects of distributional training” have traditionally been attributed to the difference in the number of peaks between the experimental distribution (two peaks) and the control distribution (one or zero peaks). However, none of the earlier studies fully excluded a possibly confounding effect of the dispersion in the distributions. Additionally, some studies with a non-speech control condition did not control for a possible difference between processing speech and non-speech. The current study presents an experiment that corrects both imperfections. Spanish listeners were exposed to either a bimodal distribution encompassing the Dutch contrast /ɑ/∼/a/ or a unimodal distribution with the same dispersion. Before and after training, their accuracy of categorization of [ɑ]- and [a]-tokens was measured. A traditionally calculated p-value showed no significant difference in categorization improvement between bimodally and unimodally trained participants. Because of this null result, a Bayesian method was used to assess the odds in favor of the null hypothesis. Four different Bayes factors, each calculated on a different belief in the truth value of previously found effect sizes, indicated the absence of a difference between bimodally and unimodally trained participants. The implication is that “effects of distributional training” observed in the lab are not induced by the number of peaks in the distributions. PMID:26441719

  7. Multilevel Analysis of Trachomatous Trichiasis and Corneal Opacity in Nigeria: The Role of Environmental and Climatic Risk Factors on the Distribution of Disease.

    PubMed

    Smith, Jennifer L; Sivasubramaniam, Selvaraj; Rabiu, Mansur M; Kyari, Fatima; Solomon, Anthony W; Gilbert, Clare

    2015-01-01

    The distribution of trachoma in Nigeria is spatially heterogeneous, with large-scale trends observed across the country and more local variation within areas. Relative contributions of individual and cluster-level risk factors to the geographic distribution of disease remain largely unknown. The primary aim of this analysis is to assess the relationship between climatic factors and trachomatous trichiasis (TT) and/or corneal opacity (CO) due to trachoma in Nigeria, while accounting for the effects of individual risk factors and spatial correlation. In addition, we explore the relative importance of variation in the risk of trichiasis and/or corneal opacity (TT/CO) at different levels. Data from the 2007 National Blindness and Visual Impairment Survey were used for this analysis, which included a nationally representative sample of adults aged 40 years and above. Complete data were available from 304 clusters selected using a multi-stage stratified cluster-random sampling strategy. All participants (13,543 individuals) were interviewed and examined by an ophthalmologist for the presence or absence of TT and CO. In addition to field-collected data, remotely sensed climatic data were extracted for each cluster and used to fit Bayesian hierarchical logistic models to disease outcome. The risk of TT/CO was associated with factors at both the individual and cluster levels, with approximately 14% of the total variation attributed to the cluster level. Beyond established individual risk factors (age, gender and occupation), there was strong evidence that environmental/climatic factors at the cluster-level (lower precipitation, higher land surface temperature, higher mean annual temperature and rural classification) were also associated with a greater risk of TT/CO. This study establishes the importance of large-scale risk factors in the geographical distribution of TT/CO in Nigeria, supporting anecdotal evidence that environmental conditions are associated with increased

  8. Multilevel Analysis of Trachomatous Trichiasis and Corneal Opacity in Nigeria: The Role of Environmental and Climatic Risk Factors on the Distribution of Disease

    PubMed Central

    Smith, Jennifer L.; Sivasubramaniam, Selvaraj; Rabiu, Mansur M.; Kyari, Fatima; Solomon, Anthony W.; Gilbert, Clare

    2015-01-01

    The distribution of trachoma in Nigeria is spatially heterogeneous, with large-scale trends observed across the country and more local variation within areas. Relative contributions of individual and cluster-level risk factors to the geographic distribution of disease remain largely unknown. The primary aim of this analysis is to assess the relationship between climatic factors and trachomatous trichiasis (TT) and/or corneal opacity (CO) due to trachoma in Nigeria, while accounting for the effects of individual risk factors and spatial correlation. In addition, we explore the relative importance of variation in the risk of trichiasis and/or corneal opacity (TT/CO) at different levels. Data from the 2007 National Blindness and Visual Impairment Survey were used for this analysis, which included a nationally representative sample of adults aged 40 years and above. Complete data were available from 304 clusters selected using a multi-stage stratified cluster-random sampling strategy. All participants (13,543 individuals) were interviewed and examined by an ophthalmologist for the presence or absence of TT and CO. In addition to field-collected data, remotely sensed climatic data were extracted for each cluster and used to fit Bayesian hierarchical logistic models to disease outcome. The risk of TT/CO was associated with factors at both the individual and cluster levels, with approximately 14% of the total variation attributed to the cluster level. Beyond established individual risk factors (age, gender and occupation), there was strong evidence that environmental/climatic factors at the cluster-level (lower precipitation, higher land surface temperature, higher mean annual temperature and rural classification) were also associated with a greater risk of TT/CO. This study establishes the importance of large-scale risk factors in the geographical distribution of TT/CO in Nigeria, supporting anecdotal evidence that environmental conditions are associated with increased

  9. Factors and processes shaping the population structure and distribution of genetic variation across the species range of the freshwater snail radix balthica (Pulmonata, Basommatophora)

    PubMed Central

    2011-01-01

    Background Factors and processes shaping the population structure and spatial distribution of genetic diversity across a species' distribution range are important in determining the range limits. We comprehensively analysed the influence of recurrent and historic factors and processes on the population genetic structure, mating system and the distribution of genetic variability of the pulmonate freshwater snail Radix balthica. This analysis was based on microsatellite variation and mitochondrial haplotypes using Generalised Linear Statistical Modelling in a Model Selection framework. Results Populations of R. balthica were found throughout North-Western Europe with range margins marked either by dispersal barriers or the presence of other Radix taxa. Overall, the population structure was characterised by distance independent passive dispersal mainly along a Southwest-Northeast axis, the absence of isolation-by-distance together with rather isolated and genetically depauperated populations compared to the variation present in the entire species due to strong local drift. A recent, climate driven range expansion explained most of the variance in genetic variation, reducing at least temporarily the genetic variability in this area. Other factors such as geographic marginality and dispersal barriers play only a minor role. Conclusions To our knowledge, such a population structure has rarely been reported before. It might nevertheless be typical for passively dispersed, patchily distributed taxa (e.g. freshwater invertebrates). The strong local drift implied in such a structure is expected to erode genetic variation at both neutral and coding loci and thus probably diminish evolutionary potential. This study shows that the analysis of multiple factors is crucial for the inference of the processes shaping the distribution of genetic variation throughout species ranges. PMID:21599918

  10. Factors Affecting the Evolution of Hurricane Erin (2001) and the Distributions of Hydrometeors: Role of Microphysical Processes.

    NASA Astrophysics Data System (ADS)

    McFarquhar, Greg M.; Zhang, Henian; Heymsfield, Gerald; Hood, Robbie; Dudhia, Jimy; Halverson, Jeffrey B.; Marks, Frank, Jr.

    2006-01-01

    Fine-resolution simulations of Hurricane Erin are conducted using the fifth-generation Pennsylvania State University NCAR Mesoscale Model (MM5) to investigate roles of thermodynamic, boundary layer, and microphysical processes on Erin’s structure and evolution. Choice of boundary layer scheme has the biggest impact on simulations, with the minimum surface pressure (Pmin) averaged over the last 18 h (when Erin is relatively mature) varying by over 20 hPa. Over the same period, coefficients used to describe graupel fall speeds (Vg) affect Pmin by up to 7 hPa, almost equivalent to the maximum 9-hPa difference between microphysical parameterization schemes; faster Vg and schemes with more hydrometeor categories generally give lower Pmin. Compared to radar reflectivity factor (Z) observed by the NOAA P-3 lower fuselage radar and the NASA ER-2 Doppler radar (EDOP) in Erin, all simulations overpredict the normalized frequency of occurrence of Z larger than 40 dBZ and underpredict that between 20 and 40 dBZ near the surface; simulations overpredict Z larger than 25 to 30 dBZ and underpredict that between 15 and 25 or 30 dBZ near the melting layer, the upper limit depending on altitude. Brightness temperatures (Tb) computed from modeled fields at 37.1- and 85.5-GHz channels that respond to scattering by graupel-size ice show enhanced scattering, mainly due to graupel, compared to observations. Simulated graupel mixing ratios are about 10 times larger than values observed in other hurricanes. For the control run at 6.5 km averaged over the last 18 simulated hours, Doppler velocities computed from modeled fields (Vdop) greater than 5 m s-1 make up 12% of Erin’s simulated area for the base simulation but less than 2% of the observed area. In the eyewall, 5% of model updrafts above 9 km are stronger than 10 m s-1, whereas statistics from other hurricanes show that 5% of updrafts are stronger than only 5 m s-1. Variations in distributions of Z, vertical motion, and graupel

  11. Calculation of the sun protection factor of sunscreens with different vehicles using measured film thickness distribution - Comparison with the SPF in vitro.

    PubMed

    Sohn, Myriam; Herzog, Bernd; Osterwalder, Uli; Imanidis, Georgios

    2016-06-01

    The sun protection factor (SPF) depends on UV filter composition, and amount and type of vehicle of the applied sunscreen. In an earlier work, we showed that the vehicle affected the average thickness of sunscreen film that is formed upon application to a skin substrate and that film thickness correlated significantly with SPF in vitro. In the present study, we quantitatively assess the role for sunscreen efficacy of the complete film thickness frequency distribution of sunscreen measured with an oil-in-water cream, an oil-in-water spray, a gel, a water-in-oil, and an alcoholic spray formulation. A computational method is employed to determine SPF in silico from calculated UV transmittance based on experimental film thickness and thickness distribution, and concentration and spectral properties of the UV filters. The investigated formulations exhibited different SPFs in vitro and different film thickness distributions especially in the small thickness range. We found a very good agreement between SPF in silico and SPF in vitro for all sunscreens. This result establishes the relationship between sun protection and the film thickness distribution actually formed by the applied sunscreen and demonstrates that variation in SPF between formulations is primarily due to their film forming properties. It also opens the possibility to integrate the influence of vehicle into tools for in silico prediction of the performance of sunscreen formulations. For this, the use of the Gamma distribution was found to be appropriate for describing film thickness distribution. PMID:27045276

  12. Environmental factors associated with the distribution of Anopheles gambiae s.s in Ghana; an important vector of lymphatic filariasis and malaria.

    PubMed

    de Souza, Dziedzom; Kelly-Hope, Louise; Lawson, Bernard; Wilson, Michael; Boakye, Daniel

    2010-01-01

    Anopheles gambiae s.s mosquitoes are important vectors of lymphatic filariasis (LF) and malaria in Ghana. To better understand their ecological aspects and influence on disease transmission, we examined the spatial distribution of the An. gambiae (M and S) molecular forms and associated environmental factors, and determined their relationship with disease prevalence. Published and current data available on the An. gambiae species in Ghana were collected in a database for analysis, and the study sites were georeferenced and mapped. Using the An. gambiae s.s sites, environmental data were derived from climate, vegetation and remote-sensed satellite sources, and disease prevalence data from existing LF and malaria maps in the literature. The data showed that An. gambiae M and S forms were sympatric in most locations. However, the S form predominated in the central region, while the M form predominated in the northern and coastal savanna regions. Bivariate and multiple regression analyses identified temperature as a key factor distinguishing their distributions. An. gambiae M was significantly correlated with LF, and 2.5 to 3 times more prevalent in the high LF zone than low to medium zones. There were no significant associations between high prevalence An. gambiae s.s locations and malaria. The distribution of the An. gambiae M and S forms and the diseases they transmit in Ghana appear to be distinct, driven by different environmental factors. This study provides useful baseline information for disease control, and future work on the An. gambiae s.s in Ghana. PMID:20360950

  13. Projecting distribution of the overwintering population of Sogatella furcifera (Hemiptera: Delphacidae), in Yunnan, China with analysis on key influencing climatic factors.

    PubMed

    Hu, Shao-Ji; Liu, Xiao-Fei; Fu, Da-Ying; Huang, Wei; Wang, Xue-Ying; Liu, Xiao-Jun; Lü, Jian-Ping; Ye, Hui

    2015-01-01

    Sogatella furcifera (Horváth) is the most threatening migratory rice pest in Yunnan, China. S. furcifera overwinters in low- altitude basins and valleys in southern Yunnan and migrates northward in spring and summer of the following year, causing serious damage during migration. The overwintering distribution, areas, and spatial pattern of S. furcifera are relevant to the migration and outbreak of this pest. Based on a 4-yr field survey (2010-2013), this study projected areas suitable for S. furcifera to overwinter using a species distribution model, and analyzed the key influencing climatic factors using principal component analysis (PCA) and ecological niche factor analysis (ENFA). Our field survey showed that the northern latitudinal- and upper elevation limits of overwintering S. furcifera was 25.4° N and 1,608 m in western Yunnan and 24.2° N and 1,563 m in eastern Yunnan. The species distribution model produced a fragmented distribution pattern, with most of which in western Yunnan and only a few in eastern Yunnan. The PCA and ENFA analyses showed that the mean temperature of the driest quarter and the precipitation of the coldest quarter significantly influenced the distribution of S. furcifera in winter. The results suggested that the complex topography, spatial differences in winter temperatures, and host availability altogether determined the distribution of overwintering S. furcifera. Compared with previous surveys, the northern latitudinal- and upper elevation limits of overwintering S. furcifera were higher, while the population became rarer in some suitable areas due to change of farmland utilization in winter and possibly climate change. PMID:26494777

  14. Projecting Distribution of the Overwintering Population of Sogatella furcifera (Hemiptera: Delphacidae), in Yunnan, China With Analysis on Key Influencing Climatic Factors

    PubMed Central

    Hu, Shao-Ji; Liu, Xiao-Fei; Fu, Da-Ying; Huang, Wei; Wang, Xue-Ying; Liu, Xiao-Jun; Lü, Jian-Ping; Ye, Hui

    2015-01-01

    Sogatella furcifera (Horváth) is the most threatening migratory rice pest in Yunnan, China. S. furcifera overwinters in low- altitude basins and valleys in southern Yunnan and migrates northward in spring and summer of the following year, causing serious damage during migration. The overwintering distribution, areas, and spatial pattern of S. furcifera are relevant to the migration and outbreak of this pest. Based on a 4-yr field survey (2010–2013), this study projected areas suitable for S. furcifera to overwinter using a species distribution model, and analyzed the key influencing climatic factors using principal component analysis (PCA) and ecological niche factor analysis (ENFA). Our field survey showed that the northern latitudinal- and upper elevation limits of overwintering S. furcifera was 25.4° N and 1,608 m in western Yunnan and 24.2° N and 1,563 m in eastern Yunnan. The species distribution model produced a fragmented distribution pattern, with most of which in western Yunnan and only a few in eastern Yunnan. The PCA and ENFA analyses showed that the mean temperature of the driest quarter and the precipitation of the coldest quarter significantly influenced the distribution of S. furcifera in winter. The results suggested that the complex topography, spatial differences in winter temperatures, and host availability altogether determined the distribution of overwintering S. furcifera. Compared with previous surveys, the northern latitudinal- and upper elevation limits of overwintering S. furcifera were higher, while the population became rarer in some suitable areas due to change of farmland utilization in winter and possibly climate change. PMID:26494777

  15. Exact random-walk models in crystallographic statistics. V. Non-symmetrically bounded distributions of structure-factor magnitudes.

    PubMed

    Shmueli, U; Rabinovich, S; Weiss, G H

    1990-04-01

    Derivations of exactly formulated Fourier-series representations of probability density functions (p.d.f.'s) of the magnitude of the structure factor are based on the fact that the structure factor and its real and imaginary parts are bounded. In some situations the bounds of the real and imaginary parts of the structure factor are different, and this gives rise to modified forms of the p.d.f.'s. Three physical examples that call for such modifications are investigated: (i) effect of dispersive scatterers on the p.d.f. of a centrosymmetric structure factor, (ii) effect of the presence of a centrosymmetric fragment in the asymmetric unit of a non-centrosymmetric space group, and (iii) effect of heavy scatterers in special positions of a non-centrosymmetric space group, where the imaginary part of the trigonometric structure factor for these special positions vanishes by symmetry. The general form of an exact Fourier p.d.f., taking account of such modifications, is derived, and expressions for Fourier coefficients are obtained for selected examples of the above three situations. It is seen that the effects of pseudocentrosymmetry may be most pronounced and those of dispersion are significant mainly in the range of small values of the structure factor. PMID:2322430

  16. 40 CFR Table W - 7 of Subpart W of Part 98-Default Methane Emission Factors for Natural Gas Distribution

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 0.772 Open-ended Line 26.131 Population Emission Factors—Below Grade Metering-Regulating station 1..., Inlet Pressure 100 to 300 psig 0.20 Below Grade M&R Station, Inlet Pressure Population....13 Cast Iron 27.25 Population Emission Factors—Distribution Services, Gas Service 4 Unprotected...

  17. 40 CFR Table W - 7 of Subpart W of Part 98-Default Methane Emission Factors for Natural Gas Distribution

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 0.772 Open-ended Line 26.131 Population Emission Factors—Below Grade Metering-Regulating station 1..., Inlet Pressure 100 to 300 psig 0.20 Below Grade M&R Station, Inlet Pressure Population....13 Cast Iron 27.25 Population Emission Factors—Distribution Services, Gas Service 4 Unprotected...

  18. Spatial distribution and risk factors of highly pathogenic avian influenza (HPAI) H5N1 in China

    USGS Publications Warehouse

    Martin, V.; Pfeiffer, D.U.; Zhou, X.; Xiao, X.; Prosser, D.J.; Guo, F.; Gilbert, M.

    2011-01-01

    Highly pathogenic avian influenza (HPAI) H5N1 was first encountered in 1996 in Guangdong province (China) and started spreading throughout Asia and the western Palearctic in 2004-2006. Compared to several other countries where the HPAI H5N1 distribution has been studied in some detail, little is known about the environmental correlates of the HPAI H5N1 distribution in China. HPAI H5N1 clinical disease outbreaks, and HPAI virus (HPAIV) H5N1 isolated from active risk-based surveillance sampling of domestic poultry (referred to as HPAIV H5N1 surveillance positives in this manuscript) were modeled separately using seven risk variables: chicken, domestic waterfowl population density, proportion of land covered by rice or surface water, cropping intensity, elevation, and human population density. We used bootstrapped logistic regression and boosted regression trees (BRT) with cross-validation to identify the weight of each variable, to assess the predictive power of the models, and to map the distribution of HPAI H5N1 risk. HPAI H5N1 clinical disease outbreak occurrence in domestic poultry was mainly associated with chicken density, human population density, and elevation. In contrast, HPAIV H5N1 infection identified by risk-based surveillance was associated with domestic waterfowl density, human population density, and the proportion of land covered by surface water. Both models had a high explanatory power (mean AUC ranging from 0.864 to 0.967). The map of HPAIV H5N1 risk distribution based on active surveillance data emphasized areas south of the Yangtze River, while the distribution of reported outbreak risk extended further North, where the density of poultry and humans is higher. We quantified the statistical association between HPAI H5N1 outbreak, HPAIV distribution and post-vaccination levels of seropositivity (percentage of effective post-vaccination seroconversion in vaccinated birds) and found that provinces with either outbreaks or HPAIV H5N1 surveillance

  19. Spatial distribution and risk factors of highly pathogenic avian influenza (HPAI) H5N1 in China

    USGS Publications Warehouse

    Martin, Vincent; Pfeiffer, Dirk U.; Zhou, Xiaoyan; Xiao, Xiangming; Prosser, Diann J.; Guo, Fusheng; Gilbert, Marius

    2011-01-01

    Highly pathogenic avian influenza (HPAI) H5N1 was first encountered in 1996 in Guangdong province (China) and started spreading throughout Asia and the western Palearctic in 2004–2006. Compared to several other countries where the HPAI H5N1 distribution has been studied in some detail, little is known about the environmental correlates of the HPAI H5N1 distribution in China. HPAI H5N1 clinical disease outbreaks, and HPAI virus (HPAIV) H5N1 isolated from active risk-based surveillance sampling of domestic poultry (referred to as HPAIV H5N1 surveillance positives in this manuscript) were modeled separately using seven risk variables: chicken, domestic waterfowl population density, proportion of land covered by rice or surface water, cropping intensity, elevation, and human population density. We used bootstrapped logistic regression and boosted regression trees (BRT) with cross-validation to identify the weight of each variable, to assess the predictive power of the models, and to map the distribution of HPAI H5N1 risk. HPAI H5N1 clinical disease outbreak occurrence in domestic poultry was mainly associated with chicken density, human population density, and elevation. In contrast, HPAIV H5N1 infection identified by risk-based surveillance was associated with domestic waterfowl density, human population density, and the proportion of land covered by surface water. Both models had a high explanatory power (mean AUC ranging from 0.864 to 0.967). The map of HPAIV H5N1 risk distribution based on active surveillance data emphasized areas south of the Yangtze River, while the distribution of reported outbreak risk extended further North, where the density of poultry and humans is higher. We quantified the statistical association between HPAI H5N1 outbreak, HPAIV distribution and post-vaccination levels of seropositivity (percentage of effective post-vaccination seroconversion in vaccinated birds) and found that provinces with either outbreaks or HPAIV H5N1 surveillance

  20. Spatial Distribution and Risk Factors of Highly Pathogenic Avian Influenza (HPAI) H5N1 in China

    PubMed Central

    Martin, Vincent; Pfeiffer, Dirk U.; Zhou, Xiaoyan; Xiao, Xiangming; Prosser, Diann J.; Guo, Fusheng; Gilbert, Marius

    2011-01-01

    Highly pathogenic avian influenza (HPAI) H5N1 was first encountered in 1996 in Guangdong province (China) and started spreading throughout Asia and the western Palearctic in 2004–2006. Compared to several other countries where the HPAI H5N1 distribution has been studied in some detail, little is known about the environmental correlates of the HPAI H5N1 distribution in China. HPAI H5N1 clinical disease outbreaks, and HPAI virus (HPAIV) H5N1 isolated from active risk-based surveillance sampling of domestic poultry (referred to as HPAIV H5N1 surveillance positives in this manuscript) were modeled separately using seven risk variables: chicken, domestic waterfowl population density, proportion of land covered by rice or surface water, cropping intensity, elevation, and human population density. We used bootstrapped logistic regression and boosted regression trees (BRT) with cross-validation to identify the weight of each variable, to assess the predictive power of the models, and to map the distribution of HPAI H5N1 risk. HPAI H5N1 clinical disease outbreak occurrence in domestic poultry was mainly associated with chicken density, human population density, and elevation. In contrast, HPAIV H5N1 infection identified by risk-based surveillance was associated with domestic waterfowl density, human population density, and the proportion of land covered by surface water. Both models had a high explanatory power (mean AUC ranging from 0.864 to 0.967). The map of HPAIV H5N1 risk distribution based on active surveillance data emphasized areas south of the Yangtze River, while the distribution of reported outbreak risk extended further North, where the density of poultry and humans is higher. We quantified the statistical association between HPAI H5N1 outbreak, HPAIV distribution and post-vaccination levels of seropositivity (percentage of effective post-vaccination seroconversion in vaccinated birds) and found that provinces with either outbreaks or HPAIV H5N1 surveillance

  1. Environmental Factors Controlling the Distribution of Symbiodinium Harboured by the Coral Acropora millepora on the Great Barrier Reef

    PubMed Central

    Cooper, Timothy F.; Berkelmans, Ray; Ulstrup, Karin E.; Weeks, Scarla; Radford, Ben; Jones, Alison M.; Doyle, Jason; Canto, Marites; O'Leary, Rebecca A.; van Oppen, Madeleine J. H.

    2011-01-01

    Background The Symbiodinium community associated with scleractinian corals is widely considered to be shaped by seawater temperature, as the coral's upper temperature tolerance is largely contingent on the Symbiodinium types harboured. Few studies have challenged this paradigm as knowledge of other environmental drivers on the distribution of Symbiodinium is limited. Here, we examine the influence of a range of environmental variables on the distribution of Symbiodinium associated with Acropora millepora collected from 47 coral reefs spanning 1,400 km on the Great Barrier Reef (GBR), Australia. Methodology/Principal Findings The environmental data included Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data at 1 km spatial resolution from which a number of sea surface temperature (SST) and water quality metrics were derived. In addition, the carbonate and mud composition of sediments were incorporated into the analysis along with in situ water quality samples for a subset of locations. Analyses were conducted at three spatio-temporal scales [GBR (regional-scale), Whitsunday Islands (local-scale) and Keppel Islands/Trunk Reef (temporal)] to examine the effects of scale on the distribution patterns. While SST metrics were important drivers of the distribution of Symbiodinium types at regional and temporal scales, our results demonstrate that spatial variability in water quality correlates significantly with Symbiodinium distribution at local scales. Background levels of Symbiodinium types were greatest at turbid inshore locations of the Whitsunday Islands where SST predictors were not as important. This was not the case at regional scales where combinations of mud and carbonate sediment content coupled with SST anomalies and mean summer SST explained 51.3% of the variation in dominant Symbiodinium communities. Conclusions/Significance Reef corals may respond to global-scale stressors such as climate change through changes in their resident symbiont

  2. von Willebrand Factor-Rich Platelet Thrombi in the Liver Cause Sinusoidal Obstruction Syndrome following Oxaliplatin-Based Chemotherapy

    PubMed Central

    Nishigori, Naoto; Matsumoto, Masanori; Koyama, Fumikazu; Hayakawa, Masaki; Hatakeyayama, Kinta; Ko, Saiho; Fujimura, Yoshihiro; Nakajima, Yoshiyuki

    2015-01-01

    Oxaliplatin-based chemotherapy is widely used to treat advanced colorectal cancer (CRC). Sinusoidal obstruction syndrome (SOS) due to oxaliplatin is a serious type of chemotherapy-associated liver injury (CALI) in CRC patients. SOS is thought to be caused by the sinusoidal endothelial cell damage, which results in the release of unusually-large von Willebrand factor multimers (UL-VWFMs) from endothelial cells. To investigate the pathophysiology of CALI after oxaliplatin-based chemotherapy, we analyzed plasma concentration of von Willebrand factor (VWF) and the distribution of VWFMs in CRC patients. Twenty-three patients with advanced CRC who received oxaliplatin-based chemotherapy with (n = 6) and without (n = 17) bevacizumab were analyzed. CALI (n = 6) and splenomegaly (n = 9) were found only in patients who did not treated with bevacizumab. Plasma VWF antigen (VWF:Ag) and serum aspartate aminotransferase (AST) levels increased after chemotherapy only in patients without bevacizumab. VWFM analysis in patients who did not receive bevacizumab showed the presence of UL-VWFMs and absence of high molecular weight VWFMs during chemotherapy, especially in those with CALI. In addition, plasma VWF:Ag and AST levels increased after chemotherapy in patients with splenomegaly (n = 9), but not in patients without splenomegaly (n = 14). Histological findings in the liver tissue of patients who did not receive bevacizumab included sinusoidal dilatation and microthrombi in the sinusoids. Many microthrombi were positive for both anti-IIb/IIIa and anti-VWF antibodies. Plasma UL-VWFM levels might be increased by damage to endothelial cells as a result of oxaliplatin-based chemotherapy. Bevacizumab could prevent CALI and splenomegaly through inhibition of VWF-rich platelet thrombus formation. PMID:26580395

  3. Spatial and non-spatial risk factors associated with cage-level distribution of infectious salmon anaemia at three Atlantic salmon, Salmo salar L., farms in Maine, USA.

    PubMed

    Gustafson, L; Ellis, S; Robinson, T; Marenghi, F; Merrill, P; Hawkins, L; Giray, C; Wagner, B

    2007-02-01

    The distribution of infectious salmon anaemia (ISA) was examined among 80 cages from three Atlantic salmon grow-out farms in Maine, USA that were stocked with smolts from a single hatchery. Cage-level disease was broadly defined as one or more moribund fish testing positive for infectious salmon anaemia virus (ISAV) by RT-PCR and a second confirmatory test (IFAT, culture or genotype sequence). Spatio-temporal and cage-level risks were explored using logistic regression and survival analysis. Non-spatial risk factors associated with ISA, or shortened survival time to disease, included increased predation, trucking company choice for smolt transfers, a finely-sedimented benthic substrate, and smaller average size of smolts at stocking. Univariable analysis identified the time-dependent spatial factor 'adjacency to newly infected cages' to be predictive of new infection in neighbouring cages 11-12 weeks later. However, none of the spatial factors, or their lags retained relevance in multiple-variable models. The results suggest a diffuse distribution of virus exposure throughout infected sites, with host-susceptibility factors probably influencing disease manifestation in individual cages. The narrow focus of the current study may limit application of the findings to other sites and year-classes. However, these data support the relevance of husbandry efforts to optimize fish health in regions affected by ISAV. PMID:17298565

  4. Comparison of methods for generation of absolute reflectance-factor values for bidirectional reflectance-distribution function studies.

    PubMed

    Feng, X; Schott, J R; Gallagher, T

    1993-03-01

    Currently, spectrophotometric standard reference materials are calibrated only by using the illumination and viewing geometries recommended by the Commission Internationale de l'Eclairage, and for some geometries the spectral range is limited to the visible wavelengths. A need exists for procedures that calibrate standards at many other geometries and for a broader spectral range. Two methods for calibrating the spectral bidirectional reflectance factor are described. The absolute bidirectional reflectance factor of a sintered polytetrafluoroethylene (PTFE) sample is determined for nearly all the possible illumination and viewing geometries from 400 nm to 2500 nm. The references are a 45/0 reflectance standard calibrated by the National Institute of Standards and Technology and a sintered PTFE sample with a directional, hemispherical reflectance factor traceable to the Institute. The results of the two methods agree to within 0.01 in reflectance factor values. With this PTFE sample as a transfer standard, the instrument described can also be used to measure the absolute bidirectional reflectance factor at nearly all the illumination and viewing geometries from 400 nm to 2500 nm. PMID:20820258

  5. Applying of Factor Analyses for Determination of Trace Elements Distribution in Water from River Vardar and Its Tributaries, Macedonia/Greece

    PubMed Central

    Popov, Stanko Ilić; Stafilov, Trajče; Šajn, Robert; Tănăselia, Claudiu; Bačeva, Katerina

    2014-01-01

    A systematic study was carried out to investigate the distribution of fifty-six elements in the water samples from river Vardar (Republic of Macedonia and Greece) and its major tributaries. The samples were collected from 27 sampling sites. Analyses were performed by mass spectrometry with inductively coupled plasma (ICP-MS) and atomic emission spectrometry with inductively coupled plasma (ICP-AES). Cluster and R mode factor analysis (FA) was used to identify and characterise element associations and four associations of elements were determined by the method of multivariate statistics. Three factors represent the associations of elements that occur in the river water naturally while Factor 3 represents an anthropogenic association of the elements (Cd, Ga, In, Pb, Re, Tl, Cu, and Zn) introduced in the river waters from the waste waters from the mining and metallurgical activities in the country. PMID:24587756

  6. Kinetic and thermodynamic factors controlling the distribution of SO32- and Na+ in calcites and selected aragonites

    USGS Publications Warehouse

    Busenberg, E.; Niel, Plummer L.

    1985-01-01

    Significant amounts of SO42-, Na+, and OH- are incorporated in marine biogenic calcites. Biogenic high Mg-calcites average about 1 mole percent SO42-. Aragonites and most biogenic low Mg-calcites contain significant amounts of Na+, but very low concentrations of SO42-. The SO42- content of non-biogenic calcites and aragonites investigated was below 100 ppm. The presence of Na+ and SO42- increases the unit cell size of calcites. The solid-solutions show a solubility minimum at about 0.5 mole percent SO42- beyond which the solubility rapidly increases. The solubility product of calcites containing 3 mole percent SO42- is the same as that of aragonite. Na+ appears to have very little effect on the solubility product of calcites. The amounts of Na+ and SO42- incorporated in calcites vary as a function of the rate of crystal growth. The variation of the distribution coefficient (D) of SO42- in calcite at 25.0??C and 0.50 molal NaCl is described by the equation D = k0 + k1R where k0 and k1 are constants equal to 6.16 ?? 10-6 and 3.941 ?? 10-6, respectively, and R is the rate of crystal growth of calcite in mg??min-1??g-1 of seed. The data on Na+ are consistent with the hypothesis that a significant amount of Na+ occupies interstitial positions in the calcite structure. The distribution of Na+ follows a Freundlich isotherm and not the Berthelot-Nernst distribution law. The numerical value of the Na+ distribution coefficient in calcite is probably dependent on the number of defects in the calcite structure. The Na+ contents of calcites are not very accurate indicators of environmental salinities. ?? 1985.

  7. MODELS OF THE INTERACTION OF MORTALITY AND THE EVOLUTION OF RISK FACTOR DISTRIBUTION: A GENERAL STOCHASTIC PROCESS FORMULATION (JOURNAL VERSION)

    EPA Science Inventory

    Generally, analyses of longitudinal studies of chronic disease risks do not directly model the change with time of risk factor values and the interactions of those changes with risk levels. Failure to account for such process characteristics can lead to incorrect inferences about...

  8. Risk Factors and Spatial Distribution of Schistosoma mansoni Infection among Primary School Children in Mbita District, Western Kenya

    PubMed Central

    Nagi, Sachiyo; Chadeka, Evans A.; Sunahara, Toshihiko; Mutungi, Faith; Justin, Yombo K. Dan; Kaneko, Satoshi; Ichinose, Yoshio; Matsumoto, Sohkichi; Njenga, Sammy M.; Hashizume, Masahiro; Shimada, Masaaki; Hamano, Shinjiro

    2014-01-01

    Background An increasing risk of Schistosoma mansoni infection has been observed around Lake Victoria, western Kenya since the 1970s. Understanding local transmission dynamics of schistosomiasis is crucial in curtailing increased risk of infection. Methodology/Principal Findings We carried out a cross sectional study on a population of 310 children from eight primary schools. Overall, a total of 238 (76.8%) children were infected with S. mansoni, while seven (2.3%) had S. haematobium. The prevalence of hookworm, Trichuris trichiura and Ascaris lumbricoides were 6.1%, 5.2% and 2.3%, respectively. Plasmodium falciparum was the only malaria parasite detected (12.0%). High local population density within a 1 km radius around houses was identified as a major independent risk factor of S. mansoni infection. A spatial cluster of high infection risk was detected around the Mbita causeway following adjustment for population density and other potential risk factors. Conclusions/Significance Population density was shown to be a major factor fuelling schistosome infection while individual socio-economic factors appeared not to affect the infection risk. The high-risk cluster around the Mbita causeway may be explained by the construction of an artificial pathway that may cause increased numbers of S. mansoni host snails through obstruction of the waterway. This construction may have, therefore, a significant negative impact on the health of the local population, especially school-aged children who frequently come in contact with lake water. PMID:25058653

  9. Characteristics of trace metals in traffic-derived particles in Hsuehshan Tunnel, Taiwan: size distribution, fingerprinting metal ratio, and emission factor

    NASA Astrophysics Data System (ADS)

    Lin, Y.-C.; Tsai, C.-J.; Wu, Y.-C.; Zhang, R.; Chi, K.-H.; Huang, Y.-T.; Lin, S.-H.; Hsu, S.-C.

    2014-05-01

    Traffic emissions are a significant source of airborne particulate matter (PM) in ambient environments. These emissions contain high abundance of toxic metals and thus pose adverse effects on human health. Size-fractionated aerosol samples were collected from May to September 2013 by using micro-orifice uniform deposited impactor (MOUDI). Sample collection was conducted simultaneously at the inlet and outlet sites of Hsuehshan Tunnel in northern Taiwan, which is the second longest freeway tunnel (12.9 km) in Asia. Such endeavor aims to characterize the chemical constituents, size distributions, and fingerprinting ratios, as well as the emission factors of particulate metals emitted by vehicle fleets. A total of 36 metals in size-resolved aerosols were determined through inductively coupled plasma mass spectrometry. Three major groups, namely, tailpipe emissions (Zn, Pb, and V), wear debris (Cu, Cd, Fe, Ga, Mn, Mo, Sb, and Sn), and resuspended dust (Ca, Mg, K, and Rb), of airborne PM metals were categorized on the basis of the results of enrichment factor, correlation matrix, and principal component analysis. Size distributions of wear-originated metals resembled the pattern of crustal elements, which were predominated by super-micron particulates (PM1-10). By contrast, tailpipe exhaust elements such as Zn, Pb, and V were distributed mainly in submicron particles. By employing Cu as a tracer of wear abrasion, several inter-metal ratios, including Fe/Cu (14), Ba/Cu (1.05), Sb/Cu (0.16), Sn/Cu (0.10), and Ga/Cu (0.03), served as fingerprints for wear debris. Emission factor of PM10 mass was estimated to be 7.7 mg vkm-1. The metal emissions were mostly predominated in super-micron particles (PM1-10). Finally, factors that possibly affect particulate metal emissions inside Hsuehshan Tunnel are discussed.

  10. The large-scale distribution of ammonia oxidizers in paddy soils is driven by soil pH, geographic distance, and climatic factors

    PubMed Central

    Hu, Hang-Wei; Zhang, Li-Mei; Yuan, Chao-Lei; Zheng, Yong; Wang, Jun-Tao; Chen, Deli; He, Ji-Zheng

    2015-01-01

    Paddy soils distribute widely from temperate to tropical regions, and are characterized by intensive nitrogen fertilization practices in China. Mounting evidence has confirmed the functional importance of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in soil nitrification, but little is known about their biogeographic distribution patterns in paddy ecosystems. Here, we used barcoded pyrosequencing to characterize the effects of climatic, geochemical and spatial factors on the distribution of ammonia oxidizers from 11 representative rice-growing regions (75–1945 km apart) of China. Potential nitrification rates varied greatly by more than three orders of magnitude, and were significantly correlated with the abundances of AOA and AOB. The community composition of ammonia oxidizer was affected by multiple factors, but changes in relative abundances of the major lineages could be best predicted by soil pH. The alpha diversity of AOA and AOB displayed contrasting trends over the gradients of latitude and atmospheric temperature, indicating a possible niche separation between AOA and AOB along the latitude. The Bray–Curtis dissimilarities in ammonia-oxidizing community structure significantly increased with increasing geographical distance, indicating that more geographically distant paddy fields tend to harbor more dissimilar ammonia oxidizers. Variation partitioning analysis revealed that spatial, geochemical and climatic factors could jointly explain majority of the data variation, and were important drivers defining the ecological niches of AOA and AOB. Our findings suggest that both AOA and AOB are of functional importance in paddy soil nitrification, and ammonia oxidizers in paddy ecosystems exhibit large-scale biogeographic patterns shaped by soil pH, geographic distance, and climatic factors. PMID:26388866

  11. The large-scale distribution of ammonia oxidizers in paddy soils is driven by soil pH, geographic distance, and climatic factors.

    PubMed

    Hu, Hang-Wei; Zhang, Li-Mei; Yuan, Chao-Lei; Zheng, Yong; Wang, Jun-Tao; Chen, Deli; He, Ji-Zheng

    2015-01-01

    Paddy soils distribute widely from temperate to tropical regions, and are characterized by intensive nitrogen fertilization practices in China. Mounting evidence has confirmed the functional importance of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in soil nitrification, but little is known about their biogeographic distribution patterns in paddy ecosystems. Here, we used barcoded pyrosequencing to characterize the effects of climatic, geochemical and spatial factors on the distribution of ammonia oxidizers from 11 representative rice-growing regions (75-1945 km apart) of China. Potential nitrification rates varied greatly by more than three orders of magnitude, and were significantly correlated with the abundances of AOA and AOB. The community composition of ammonia oxidizer was affected by multiple factors, but changes in relative abundances of the major lineages could be best predicted by soil pH. The alpha diversity of AOA and AOB displayed contrasting trends over the gradients of latitude and atmospheric temperature, indicating a possible niche separation between AOA and AOB along the latitude. The Bray-Curtis dissimilarities in ammonia-oxidizing community structure significantly increased with increasing geographical distance, indicating that more geographically distant paddy fields tend to harbor more dissimilar ammonia oxidizers. Variation partitioning analysis revealed that spatial, geochemical and climatic factors could jointly explain majority of the data variation, and were important drivers defining the ecological niches of AOA and AOB. Our findings suggest that both AOA and AOB are of functional importance in paddy soil nitrification, and ammonia oxidizers in paddy ecosystems exhibit large-scale biogeographic patterns shaped by soil pH, geographic distance, and climatic factors. PMID:26388866

  12. Relation between anthropometric measures of fat distribution and cardiovascular risk factors in overweight pre- and postmenopausal women.

    PubMed

    Perry, A C; Applegate, E B; Allison, M L; Miller, P C; Signorile, J F

    1997-10-01

    This study compared three different measures of central adiposity: waist-to-hip ratio (WHR), waist-to-height ratio (WSHT), and waist circumference with cardiovascular risk factors, including serum lipoproteins and blood pressure in overweight pre- (n = 115) and postmenopausal (n = 46) women. Premenopausal women had a mean age of 35.6 +/- 6.79 y and a mean body mass index (BMI; in kg/m2) of 37.08 +/- 6.01. Postmenopausal women had a mean age of 52.5 +/- 8.19 y and a mean BMI of 38.75 +/- 6.9. Although several correlations between central adiposity and serum lipoproteins and blood pressure were significant, they were unaffected by menopausal status. There were also no significant differences among the three measures of central adiposity in relation to cardiovascular risk factors within premenopausal and postmenopausal groups. An analysis of covariance controlling for BMI showed that after stratifying WSHT into tertiles, a significant interaction of WSHT group by menopausal status was found for systolic blood pressure (SBP) (P = 0.019). Postmenopausal women had a significantly greater SBP than premenopausal women in the lowest and highest tertiles (P = 0.001); however, this pattern was not shown in the middle WSHT tertile. The relation between central adiposity and cardiovascular risk factors appears to be unchanged after menopause, except when WSHT is used to indicate SBP. Because increased central adiposity may also indicate an increase in cardiovascular risk factors, measurements of central adiposity can be used to supplement the routine clinical evaluation of cardiovascular risk factors in both pre- and postmenopausal overweight women. PMID:9322557

  13. Deficient activity of von Willebrand factor-cleaving protease in chronic relapsing thrombotic thrombocytopenic purpura.

    PubMed

    Furlan, M; Robles, R; Solenthaler, M; Wassmer, M; Sandoz, P; Lämmle, B

    1997-05-01

    In patients with thrombotic thrombocytopenic purpura (TTP), excessive intravascular platelet aggregation has been associated with appearance in plasma of unusually large von Willebrand factor (vWF) multimers. These extremely adhesive vWF multimers may arise due to deficiency of a "depolymerase" cleaving vWF to smaller molecular forms, either by reducing the interdimeric disulfide bridges or by proteolytic degradation. We studied the activity of a recently described vWF-cleaving protease in four patients with chronic relapsing TTP. Diluted plasma samples of TTP patients were incubated with purified normal human vWF in the presence of a serine protease inhibitor, at low ionic strength, and in the presence of urea and barium ions. The extent of vWF degradation was assayed by electrophoresis in sodium dodecyl sulfate-agarose gels and immunoblotting. Four patients, that included two brothers, with chronic relapsing TTP displayed either substantially reduced levels or a complete absence of vWF-cleaving protease activity. In none of these patient plasmas was an inhibitor of or an antibody against the vWF-cleaving protease established. Our data suggest that the unusually large vWF multimers found in TTP patients may be caused by deficient vWF-cleaving protease activity. Deficiency of this protease may be inherited in an autosomal recessive manner and seems to predispose to chronic relapsing TTP. The assay of the vWF-cleaving protease activity may be used as a sensitive diagnostic tool for identification of subjects with a latent TTP tendency. PMID:9129011

  14. Neighborhood History as a Factor Shaping Syringe Distribution Networks Among Drug Users at a U.S. Syringe Exchange1

    PubMed Central

    Braine, Naomi; Acker, Caroline; Goldblatt, Cullen; Yi, Huso; Friedman, Samuel; DesJarlais, Don C.

    2008-01-01

    Throughout the US, high-visibility drug markets are concentrated in neighborhoods with few economic opportunities, while drug buyers/users are widely dispersed. A study of Pittsburgh Syringe Exchange participants provides data on travel between and network linkages across neighborhoods with different levels of drug activity. There are distinct racial patterns to syringe distribution activity within networks and across neighborhoods. Pittsburgh’s history suggests these patterns emerge from historical patterns of social and economic development. Study data demonstrate the ability of IDUs to form long term social ties across racial and geographic boundaries and use them to reduce the risk of HIV transmission. PMID:19578475

  15. Evaluation of processing factors for selected organic contaminants during virgin olive oil production: Distribution of BTEXS during olives processing.

    PubMed

    López-Blanco, Rafael; Gilbert-López, Bienvenida; Rojas-Jiménez, Rubén; Robles-Molina, José; Ramos-Martos, Natividad; García-Reyes, Juan F; Molina-Díaz, Antonio

    2016-05-15

    The presence of BTEXS (benzene, toluene, ethylbenzene, xylenes and styrene) in virgin olive oils can be attributed to environmental contamination, but also to biological processes during oil lipogenesis (styrene). In this work, the processing factor of BTEXS from olives to olive oil during its production was evaluated at lab-scale with an Abencor system. Benzene showed the lowest processing factor (15%), whereas toluene and xylenes showed an intermediate behavior (with 40-60% efficiency), and ethylbenzene and styrene were completely transferred (100%). In addition, an attempt to examine the contribution of potential sources to olives contamination with BTEXS was carried out for the first time. Two types of olives samples were classified according to their proximity to the contamination source (road). Although higher levels of BTEXS were found in samples close to roads, the concentrations were relatively low and do not constitute a major contribution to BTEXS usually detected in olive oil. PMID:26775971

  16. Relation of Vascular Growth Factors with CT-Derived Measures of Body Fat Distribution: The Framingham Heart Study

    PubMed Central

    Kaess, Bernhard M.; Pedley, Alison; Massaro, Joseph M.; Larson, Martin G.; Corsini, Erin; Hoffmann, Udo; Smith, Holly M.; Sawyer, Douglas B.; Vasan, Ramachandran S.

    2012-01-01

    Background: Visceral adiposity is associated with metabolic risk. Given that angiogenesis is a key feature of adipogenesis, variation in the association of levels of circulating vascular growth factors (and their soluble receptors) with distinct body fat compartments may explain differences in the systemic pathogenicity of regional fat depots. Methods and Results: Four body fat compartments [visceral adipose tissue (VAT), sc adipose tissue (SAT), thoracic periaortic fat, and pericardial fat] derived from computed tomography were related to serum concentrations of vascular endothelial growth factor (VEGF), the soluble VEGF receptor (fms-like tyrosine kinase-1), hepatocyte growth factor (HGF), and angiopoietin-2 and its soluble receptor (soluble tyrosine kinase with immunoglobulin-like and EGF-like domains 2 sTie-2) in 1806 Framingham Heart Study participants (mean age 44.9 yr, 44.5% women). In multivariable models, we observed positive associations between several fat compartments and VEGF and HGF levels. The magnitude of the associations were similar for VAT, SAT, and periaortic fat. We observed effect modification by sex. A stronger association was observed between VAT and HGF levels in women; higher VAT and periaortic fat were jointly associated with higher HGF concentrations (P = 0.02 and P = 0.051, respectively). In women within the highest tertile of VAT, HGF levels significantly increased with higher periaortic fat (P = 0.0005). Conclusions: In our large community-based sample, greater adiposity was associated with higher circulating growth factor levels in general. Additional studies are warranted to confirm the stronger association of VAT and periaortic fat with HGF in women and to examine its potential contribution to the sex-related differences in cardiometabolic risk. PMID:22170711

  17. Potentially harmful microalgal distribution in an area of the NW Adriatic coastline: Sampling procedure and correlations with environmental factors

    NASA Astrophysics Data System (ADS)

    Penna, Antonella; Ingarao, Cristina; Ercolessi, Manuela; Rocchi, Marco; Penna, Nunzio

    2006-10-01

    In this study, the trend of potentially Harmful Algal (HA) taxa (genera and species), was analysed along a coastal area of the NW Adriatic Sea on a monthly scale. The study included the use of a phytoplankton net for sample collection. The investigation was carried out in four sampling stations characterised by different ecological features. The composition of potentially HA phytoplankton taxa and their succession were related to the environmental factors. The potentially HA group abundance accounted for 8% of all the phytoplankton taxa considered. Multivariate analyses of environmental factors suggested that potentially HA taxa are sensitive to phosphate content: potential DSP-YTX (Diarrhetic Shellfish Poisoning-Yessotoxin) producers were positively correlated with P content ( p = 0.023), while potential ASP (Amnesic Shellfish Poisoning) producers were negatively correlated with P content ( p = 0.006). Phosphorus could be considered to be the limiting factor for phytoplankton taxa density in the NW Adriatic Sea. There was a highly positive correlation between the occurrences of potentially HA taxa and low values of salinity ( p = 0.001 for potential producers of ASP, p = 0.029 for potential DSP-YTX producers). The counting of potential HA dinoflagellates in net samples represented a more accurate estimation of potential HA abundances in the water column making it possible to concentrate a greater number of potential HA dinoflagellate cells by net sampling along the entire water column rather than by sampling only at the surface as in routine monitoring procedures.

  18. Distribution and structure of the upper sublittoral macrobenthic communities of Tróia sand beaches (Setúbal, Portugal) and their relationship with environmental factors.

    PubMed

    Vale, Maria; Cabral, Henrique; Andrade, Francisco

    2010-04-01

    The present study dealt with the spatial and temporal variability of the distribution of the upper sublittoral benthic macrofauna of the Tróia peninsula sand beaches and its relationship with abiotic environmental factors. The existence of a relationship between the data set of macrobenthic species distribution and community structure in the Sado estuary (432 individual samples) and the environmental factors in analysis was investigated. Morpho-sedimentary data analysis revealed an environmental gradient, from the marine margin (exposed marine environment) to the estuarine margin (sheltered estuarine environment). Benthic macrofauna analysis showed a gradient of increasing number of individuals, species richness and diversity from the marine margin (Exposed) to the estuarine margin (Sheltered). Canonical Correspondence Analysis showed the dominant patterns in the community structure to be explained by the environmental factors considered, the most important, of which in influencing the spatial and temporal pattern, being beach slope, organic matter and calcium carbonate contents. The structure of the sandy beach communities studied showed a clear dominance of the spatial patterns over the seasonal ones. Four assemblages were defined-(1) an assemblage dominated by Angulus tenuis, on the marine margin of the peninsula; (2) an assemblage dominated by Euclymene sp. and Apseudes latreillei, on the sea-estuary transition area and related to the presence of a Zostera spp. meadow; (3) an assemblage dominated by Glycera sp. and Scoloplos armiger, on the sea-estuary transition area; (4) an assemblage dominated by Notomastus latericeus, Nassarius reticulatus and Cyathura carinata, on the estuarine margin. PMID:20383379

  19. [Analysis on factors affecting net primary productivity distribution in Changbai Mountain based on process model for landscape scale].

    PubMed

    Zhang, Na; Yu, Guirui; Yu, Zhenliang; Zhao, Shidong

    2003-05-01

    Based on the data received from remote sensing images, the spatial distribution of annual net primary productivity (NPP) was simulated by the process model (EPPML), and the relationships between annual NPP and environmental conditions were analyzed. The results showed that NPP in 1995 was 0.680 kg C.m-2.yr.-1, mostly ranging from 0.105 to 1.241 kg C.m-2.yr.-1, accounting for 82.1%. The highest NPP (1.084 kg C.m-2.yr.-1) appears in mixed broad-leaved and Korean pine forest. Environmental conditions decide the main trend of the spatial distribution of annual NPP (Carbon) in Changbai Mountain. Soil water content had a negative correlativity with NPP, and the correlation coefficient (R) was -0.65. Therefore, water was sufficient for the growth of plants in Changbai Mountain. NPP was highly correlated with LAI (R = 0.81). When LAI was greater than 4-5 m2.m-2, NPP became saturated. NPP was also highly correlated with canopy transpiration (R = 0.77). The response of NPP on environmental conditions, LAI and canopy transpiration in Betula ermanii and broad-leaved forests were different from those in other vegetation. PMID:12924113

  20. The effect of signal variability on the histograms of anthropomorphic channel outputs: factors resulting in non-normally distributed data

    NASA Astrophysics Data System (ADS)

    Elshahaby, Fatma E. A.; Ghaly, Michael; Jha, Abhinav K.; Frey, Eric C.

    2015-03-01

    Model Observers are widely used in medical imaging for the optimization and evaluation of instrumentation, acquisition parameters and image reconstruction and processing methods. The channelized Hotelling observer (CHO) is a commonly used model observer in nuclear medicine and has seen increasing use in other modalities. An anthropmorphic CHO consists of a set of channels that model some aspects of the human visual system and the Hotelling Observer, which is the optimal linear discriminant. The optimality of the CHO is based on the assumption that the channel outputs for data with and without the signal present have a multivariate normal distribution with equal class covariance matrices. The channel outputs result from the dot product of channel templates with input images and are thus the sum of a large number of random variables. The central limit theorem is thus often used to justify the assumption that the channel outputs are normally distributed. In this work, we aim to examine this assumption for realistically simulated nuclear medicine images when various types of signal variability are present.

  1. Effect of biotic factors on the spatial distribution of stingless bees (Hymenoptera: Apidae, Meliponini) in fragmented neotropical habitats.

    PubMed

    Fierro, M M; Cruz-López, L; Sánchez, D; Villanueva-Gutiérrez, R; Vandame, R

    2012-04-01

    We recorded stingless bee colony abundance and nesting habits in three sites with different anthropogenic activities in the Soconusco region of Chiapas, Mexico: (1) agroforestry (7 hacacao crop), (2) grassland (12 ha), and (3) urban area (3 ha). A total of 67 nests were found, representing five stingless bee species, Tetragonisca angustula angustula (Lepeletier), Trigona fulviventris (Guérin), Scaptotrigona mexicana (Guérin), Scaptotrigona pectoralis (Dalla Torre), and Oxytrigona mediorufa (Cockerell). The most abundant stingless bee in each site was T. angustula angustula (>50%). The primary tree species used by the bees were Ficus spp. (Moraceae, 37.8%) and Cordia alliodora (Boraginaceae, 13.5%). The nest entrance height of T. angustula angustula (96 ± 19 cm) was different than the other species, and this bee was the only one that used all different nesting sites. Volatiles analyzed by gas chromatography from pollen collected by the stingless bees differed between bee species, but were highly similar in respect to the fragrances of the pollen collected by the same species at any site. Our data indicate that T. angustula angustula experienced low heterospecific and high intraspecific foraging overlap especially in the urban site. We observed cluster spatial distribution in grassland and in agroforestry sites. In the urban site, T. angustula angustula presented random distribution tended to disperse. Trigona fulviventris was the only overdispersed and solitary species. PMID:23950022

  2. The longitudinal and transverse distributions of the pion wave function from the present experimental data on the pion-photon transition form factor

    NASA Astrophysics Data System (ADS)

    Zhong, Tao; Wu, Xing-Gang; Huang, Tao

    2016-07-01

    The low-energy and high-energy behavior of the pion-photon transition form factor F_{π γ }(Q^2) are sensitive to the transverse and longitudinal distributions of the pion wave function, respectively. A careful study of F_{π γ }(Q^2) shall thus provide helpful constraints on the properties of the pion wave function. In this paper, we present a combined analysis of the data on F_{π γ }(Q^2) reported by the CELLO, the CLEO, the BABAR, and the BELLE Collaborations. It is performed by using the method of least squares. By using the combined measurements of the BELLE and CLEO Collaborations, the pion wave function longitudinal and transverse behavior can be fixed to a certain degree, i.e. we obtain β in [0.691,0.757] GeV and B in [0.00,0.235] for P_{χ ^2} ≥ 90 %, where β and B are two parameters of a convenient pion wave function model. It is noted that the distribution amplitude of such a pion wave function can mimic various longitudinal behaviors, as suggested in the literature under a proper choice of parameters. We observe that the CELLO, CLEO, and BELLE data are consistent with each other, all of which prefer the asymptotic-like distribution amplitude; while the BABAR data prefers a more broad distribution amplitude, such as the CZ-like one.

  3. [Spatial distribution pattern of Picea schrenkiana var. tianshanica population and its relationships with topographic factors in middle part of Tianshan Mountain].

    PubMed

    Zhang, Yu-Tao; Li, Ji-Mei; Chang, Shun-Li; Li, Xiang; Lu, Jian-Jiang

    2011-11-01

    By the method of point pattern analysis, this paper studied the spatial distribution patterns of different age class individuals in the Picea schrenkiana var. tianshanica forest in middle part of Tianshan Mountain and the influence of topographic factors on the distribution patterns. It was observed that the density of different age class individuals in the forest decreased with the increasing DBH of the individuals, and except old trees which presented a random distribution at the scale of 0-12 m, the saplings and the small, medium, and big trees were in aggregative distribution at all scales. With the increase of age class, the scale at which the individuals presented the highest aggregation degree increased, whereas the aggregation intensity declined. At small scale (0-16 m), different age class individuals appeared negative association, and the greater difference the tree age, the more significant the negative association presented. Altitude had significant positive effects on the number of medium, big, and old trees but had little effects on the number of saplings and small trees. Slope grade had significant positive effects on the number of saplings and small and medium trees, significant negative effects on the number of old trees, but little effects on the number of big trees. Concavo-convex had significant negative effects on the number of saplings and small and medium trees but had little effects on the number of big and old trees. PMID:22303653

  4. Factors influencing the structure and spatial distribution of fishes in the headwater streams of the Jaú River in the Brazilian Amazon.

    PubMed

    Kemenes, A; Forsberg, B R

    2014-08-01

    The aim of this study was to investigate the influence of spatial variation in river channels and habitats on the distribution of fish communities in the headwater streams of the Jaú River System, a blackwater tributary of the Negro River. Collections and measurements were made in 34 headwater streams during the period of November- December, 1998. Fish were captured with fish traps and hand nets along standard reaches of two meanders. Data on benthic habitat structure, stream depth and width were collected along lateral transects in each sample reach. A total of 66 fish species from 24 families were collected and classified into seven trophic guilds: allocthonous insectivore, autochthonous insectivore, general insectivore, piscivore, detritivorous planktivore, detritivorous insectivore and insectivorous piscivore. Variations in the distribution and diversity of bottom substrates were important factors influencing fish community structures in these systems. Also, variation in stream size explained the observed variability in fish communities. PMID:25627363

  5. Driving factors behind the distribution of dinocyst composition and abundance in surface sediments in a western Mediterranean coastal lagoon: report from a high resolution mapping study.

    PubMed

    Fertouna-Bellakhal, Mouna; Dhib, Amel; Béjaoui, Béchir; Turki, Souad; Aleya, Lotfi

    2014-07-15

    Species composition and abundance of dinocysts in relation to environmental factors were studied at 123 stations of surface sediment in Bizerte Lagoon. Forty-eight dinocyst types were identified, mainly dominated by Brigantidinium simplex, Votadinum spinosum, Alexandrium pseudogonyaulax, Alexandrium catenella, and Lingulodinum machaerophorum along with many round brown cysts and spiny round brown cysts. Cysts ranged from 1276 to 20126 cysts g(-1)dry weight sediment. Significant differences in cyst distribution pattern were recorded among the zones, with a higher cyst abundance occurring in the lagoon's inner areas. Redundancy analyses showed two distinct associations of dinocysts according to location and environmental variables. Ballast water discharges are potential introducers of non-indigenous species, especially harmful ones such as A. catenella and Polysphaeridium zoharyi, with currents playing a pivotal role in cyst distribution. Findings concerning harmful cyst species indicate potential seedbeds for initiation of future blooms and outbreaks of potentially toxic species in the lagoon. PMID:24841716

  6. Analysis of the factors that affect the distribution and abundance of three Neobuxbaumia species (Cactaceae) that differ in their degree of rarity

    NASA Astrophysics Data System (ADS)

    Ruedas, Marcela; Valverde, Teresa; Zavala-Hurtado, José Alejandro

    2006-03-01

    We studied three species of columnar cacti in the genus Neobuxbaumia which differ in their degree of rarity: Neobuxbaumia macrocephala (the rarest), Neobuxbaumia tetetzo (intermediate), and Neobuxbaumia mezcalaensis (the most common). To investigate the ecological factors that limit their distribution and abundance, we surveyed 80 localities within the region of Tehuacan-Cuicatlán, in Central Mexico. At each locality we measured several environmental variables, and the density of the Neobuxbaumia populations present. We used a principal component analysis (PCA) to identify the factors that are associated to the presence/absence of each species. Additionally, we carried out multiple regressions between environmental variables and population density to test whether the variation in these variables was related to changes in abundance. The results show that factors significantly affecting the distribution of these species are mean annual temperature, altitude, rainfall, and soil properties such as texture and organic matter content. N. mezcalaensis reaches maximum population densities of 14,740 plants per ha (average density = 3943 plants per ha) and is associated with localities with relatively abundant rainfall. N. tetetzo shows maximum population densities of 14,060 plants per ha (average = 3070 plants per ha), and is associated with sites located at high latitudes and with high phosphorous content in the soil. The rarest species, N. macrocephala, shows maximum densities of 1180 plants per ha (average = 607 plants per ha) and is associated with localities with high soil calcium content. The distribution of this species is limited to sites with specific values of the environmental variables recorded, conferring it a high habitat specificity which accounts for its rarity.

  7. A Framework for Federated Two-Factor Authentication Enabling Cost-Effective Secure Access to Distributed Cyberinfrastructure

    SciTech Connect

    Ezell, Matthew A; Rogers, Gary L; Peterson, Gregory D.

    2012-01-01

    As cyber attacks become increasingly sophisticated, the security measures used to mitigate the risks must also increase in sophistication. One time password (OTP) systems provide strong authentication because security credentials are not reusable, thus thwarting credential replay attacks. The credential changes regularly, making brute-force attacks significantly more difficult. In high performance computing, end users may require access to resources housed at several different service provider locations. The ability to share a strong token between multiple computing resources reduces cost and complexity. The National Science Foundation (NSF) Extreme Science and Engineering Discovery Environment (XSEDE) provides access to digital resources, including supercomputers, data resources, and software tools. XSEDE will offer centralized strong authentication for services amongst service providers that leverage their own user databases and security profiles. This work implements a scalable framework built on standards to provide federated secure access to distributed cyberinfrastructure.

  8. Perfluorooctane sulfonate (PFOS) distribution and effect factors in the water and sediment of the Yellow River Estuary, China.

    PubMed

    Wang, Shiliang; Wang, Hui; Deng, Wenjing

    2013-10-01

    The distribution of perfluorooctane sulfonate (PFOS) was investigated in a total of 15 water and sediment samples from the Yellow River Estuary, China in April 2011. The results indicated that the concentrations of PFOS in the water and sediment samples averaged 157.5 ng/L and 198.8 ng/g and ranged from 82.30 to 261.8 ng/L and 75.48 to 457.0 ng/g, respectively. The concentrations of PFOS in the sediment column increased from 45.32 to 379.98 ng/g with the decrease of the sampling depth, which showed that the increased PFOS pollution in the sediment appeared in this region in over recent years. The distribution coefficient (K d) of PFOS between water and sediment linearly increased from 0.37 to 4.80 L/g as the salinity (S‰) increased from 0.18 to 4.47. Correlation analysis revealed that K d was significantly and positively correlated to the contents of total organic carbon and clay of the sediment, and salinity. Therefore, salinity was an important parameter in controlling the sediment-water interactions and the fate or transport of PFOS in the aquatic environment. The results of this study showed that the estuary was an important sink for PFOS and suggested that PFOS might be carried with the river water and transported for long distances before it reached to the sea and largely scavenged to the sediment in the estuaries due to the change in salinity. PMID:23591678

  9. Calcareous Bio-Concretions in the Northern Adriatic Sea: Habitat Types, Environmental Factors that Influence Habitat Distributions, and Predictive Modeling.

    PubMed

    Falace, Annalisa; Kaleb, Sara; Curiel, Daniele; Miotti, Chiara; Galli, Giovanni; Querin, Stefano; Ballesteros, Enric; Solidoro, Cosimo; Bandelj, Vinko

    2015-01-01

    Habitat classifications provide guidelines for mapping and comparing marine resources across geographic regions. Calcareous bio-concretions and their associated biota have not been exhaustively categorized. Furthermore, for management and conservation purposes, species and habitat mapping is critical. Recently, several developments have occurred in the field of predictive habitat modeling, and multiple methods are available. In this study, we defined the habitats constituting northern Adriatic biogenic reefs and created a predictive habitat distribution model. We used an updated dataset of the epibenthic assemblages to define the habitats, which we verified using the fuzzy k-means (FKM) clustering method. Redundancy analysis was employed to model the relationships between the environmental descriptors and the FKM membership grades. Predictive modelling was carried out to map habitats across the basin. Habitat A (opportunistic macroalgae, encrusting Porifera, bioeroders) characterizes reefs closest to the coastline, which are affected by coastal currents and river inputs. Habitat B is distinguished by massive Porifera, erect Tunicata, and non-calcareous encrusting algae (Peyssonnelia spp.). Habitat C (non-articulated coralline, Polycitor adriaticus) is predicted in deeper areas. The onshore-offshore gradient explains the variability of the assemblages because of the influence of coastal freshwater, which is the main driver of nutrient dynamics. This model supports the interpretation of Habitat A and C as the extremes of a gradient that characterizes the epibenthic assemblages, while Habitat B demonstrates intermediate characteristics. Areas of transition are a natural feature of the marine environment and may include a mixture of habitats and species. The habitats proposed are easy to identify in the field, are related to different environmental features, and may be suitable for application in studies focused on other geographic areas. The habitat model outputs

  10. Calcareous Bio-Concretions in the Northern Adriatic Sea: Habitat Types, Environmental Factors that Influence Habitat Distributions, and Predictive Modeling

    PubMed Central

    Falace, Annalisa; Kaleb, Sara; Curiel, Daniele; Miotti, Chiara; Galli, Giovanni; Querin, Stefano; Ballesteros, Enric; Solidoro, Cosimo; Bandelj, Vinko

    2015-01-01

    Habitat classifications provide guidelines for mapping and comparing marine resources across geographic regions. Calcareous bio-concretions and their associated biota have not been exhaustively categorized. Furthermore, for management and conservation purposes, species and habitat mapping is critical. Recently, several developments have occurred in the field of predictive habitat modeling, and multiple methods are available. In this study, we defined the habitats constituting northern Adriatic biogenic reefs and created a predictive habitat distribution model. We used an updated dataset of the epibenthic assemblages to define the habitats, which we verified using the fuzzy k-means (FKM) clustering method. Redundancy analysis was employed to model the relationships between the environmental descriptors and the FKM membership grades. Predictive modelling was carried out to map habitats across the basin. Habitat A (opportunistic macroalgae, encrusting Porifera, bioeroders) characterizes reefs closest to the coastline, which are affected by coastal currents and river inputs. Habitat B is distinguished by massive Porifera, erect Tunicata, and non-calcareous encrusting algae (Peyssonnelia spp.). Habitat C (non-articulated coralline, Polycitor adriaticus) is predicted in deeper areas. The onshore-offshore gradient explains the variability of the assemblages because of the influence of coastal freshwater, which is the main driver of nutrient dynamics. This model supports the interpretation of Habitat A and C as the extremes of a gradient that characterizes the epibenthic assemblages, while Habitat B demonstrates intermediate characteristics. Areas of transition are a natural feature of the marine environment and may include a mixture of habitats and species. The habitats proposed are easy to identify in the field, are related to different environmental features, and may be suitable for application in studies focused on other geographic areas. The habitat model outputs

  11. cDNA cloning, tissue distribution, and chromosomal localization of myelodysplasia/Myeloid Leukemia Factor 2 (MLF2)

    SciTech Connect

    Kuefer, M.U.; Valentine, V.; Behm, F.G.

    1996-07-15

    A fusion gene between nucleophosmin (NPM) and myelodysplasia/myeloid leukemia factor 1 (MLF1) and myelodysplasia/myeloid leukemia factor 1 (MLF1) is formed by a recurrent t(3;5)(q25.1;q34) in myelodysplastic syndrome and acute myeloid leukemia. Here we report the identification of a novel gene, MLF2, which contains an open reading frame of 744 bp encoding a 248-amino-acid protein highly related to the previously identified MLF1 protein (63% similarity, 40% identity). In contrast to the tissue-restricted expression pattern of MLF1, and MLF2 messenger RNA is expressed ubiquitously. The MLF2 gene locus was mapped by fluorescence in situ hybridization to human chromosome 12p13, a chromosomal region frequently involved in translocations and deletions in acute leukemias of lymphoid or myeloid lineage. In a physical map of chromosome 12, MLF2 was found to reside on the yeast artificial chromosome clone 765b9. Southern blotting analysis of malignant cell DNAs prepared from a series of acute lymphoblastic leukemia cases with translocations involving chromosome arm 12p, as well as a group of acute myeloid leukemias with various cytogenetic abnormalities, failed to reveal MLF2 gene rearrangements. 19 refs., 2 figs.

  12. Prevalence and geographical distribution of canine hemotropic mycoplasma infections in Mediterranean countries and analysis of risk factors for infection.

    PubMed

    Novacco, Marilisa; Meli, Marina L; Gentilini, Fabio; Marsilio, Fulvio; Ceci, Chiara; Pennisi, Maria Grazia; Lombardo, Gabriella; Lloret, Albert; Santos, Laura; Carrapiço, Tiago; Willi, Barbara; Wolf, Godelind; Lutz, Hans; Hofmann-Lehmann, Regina

    2010-05-19

    Two hemoplasma species are known in dogs: Mycoplasma haemocanis (Mhc) and 'Candidatus Mycoplasma haematoparvum' (CMhp). Although their transmission routes are poorly understood, Rhipicephalus sanguineus has been suggested as a potential tick vector. The aim of the present study was to assess the prevalence, risk factors, and clinical importance of canine hemoplasmas in countries with a Mediterranean climate where R. sanguineus is highly prevalent using TaqMan real-time PCR, and to molecularly characterize the identified isolates. DNA (canine glyceraldehyde-3-phosphate dehydrogenase) was successfully amplified from all samples collected from 850 dogs in Italy, Spain, and Portugal, and 82 (9.6%) were PCR-positive for canine hemoplasmas (43 Mhc, 34 CMhp and 5 co-infected). The hemoplasma sample prevalence was significantly higher in Portugal (40%) than in Italy (9.5%) and Spain (2.5%). Risk factors for infection included living in kennels, young age, crossbreeding, and mange infection. No association was found with anemia. Phylogenetic analyses of the 16S rRNA and RNase P genes revealed >99% identity to other European isolates. In conclusion, canine hemoplasma infections were readily encountered in Mediterranean countries. The climate and living conditions seemed to influence canine hemoplasma prevalence. The clinical importance of canine hemoplasma infections appeared to be low, but the infection stage of the presented dogs was unknown. PMID:19931320

  13. The distribution of and factors associated with intimate terrorism and situational couple violence among a population-based sample of urban women in the United States.

    PubMed

    Frye, Victoria; Manganello, Jennifer; Campbell, Jacquelyn C; Walton-Moss, Benita; Wilt, Susan

    2006-10-01

    It has been proposed that two distinct forms of intimate partner violence exist: intimate terrorism and situational couple violence. This article describes the distribution of factors that characterize intimate terrorism and situational couple violence, including controlling behaviors, violence escalation, and injury, among a representative sample of 331 physically assaulted women living in 11 North American cities. In addition, respondent, partner, and relationship characteristics associated with each form of violence are identified. Most women who experienced physical assault also experienced controlling behavior by their male partner. In multivariate analyses, respondent's young age, violence escalation in the relationship, partner's access to guns, previous arrests for domestic violence offenses, poor mental health, and previous suicide attempts or threats were associated with intimate terrorism, defined as experiencing one or more controlling behaviors. These results suggest that situational couple violence is rare and that moderate and high levels of controlling behaviors are associated primarily with partner factors. PMID:16940397

  14. Cardiovascular risk factor levels and their relationships with overweight and fat distribution in children: the Fleurbaix Laventie Ville Santé II study

    PubMed Central

    Botton, Jérémie; Heude, Barbara; Kettaneh, Adrien; Borys, Jean-Michel; Lommez, Agnès; Bresson, Jean-Louis; Ducimetière, Pierre; Charles, Marie-Aline

    2007-01-01

    Objectives To document for the first time in a general population of French children, the prevalence and levels of cardiovascular risk factors, and to assess, separately in boys and girls, whether these risk factors were associated with fat mass distribution independently of subcutaneous overall adiposity. Subjects and design A cross sectional analysis of baseline data from 452 children (235 boys and 217 girls) aged 8–17 years included in 1999 in a population-based epidemiologic study, the Fleurbaix Laventie Ville Santé II (FLVS II) study. Methods Overweight was defined according to the International Obesity Task Force (IOTF) references and to the 90th percentiles of the French BMI curves. The thresholds of parameters defining cardiovascular and metabolic risk were the 95th percentile of the Task Force Report on High Blood Pressure in Children and Adolescents for blood pressure, and those of the American Academy of Pediatrics for lipids. Anthropometric and biologic parameters were described by gender and according to overweight. Partial correlations between cardiovascular risk factors and anthropometric measures of adiposity (BMI, sum of four skinfold thicknesses, waist circumference, waist-to-height ratio) were calculated. In a second step, these correlations were additionally adjusted for the sum of four skinfold thicknesses. Results High plasma triglycerides, high insulin concentration and low plasma HDL cholesterol were associated with all measures of adiposity (|r|≥0.20; p<0.002). When obese children were excluded, overweight children already had high triglycerides and low HDL cholesterol levels respectively 2 and 20 times more frequently than normal weight children. Among overweight children, 7.7% had at least two risk factors among high blood pressure, high plasma triglycerides or glucose, and low HDL concentrations, versus 0.25% among normal weight children (p=0.002). After adjusting for the sum of skinfolds, an independent association between the risk

  15. Relationships between antimicrobial resistance, distribution of virulence factor genes and the origin of Trueperella pyogenes isolated from domestic animals and European bison (Bison bonasus).

    PubMed

    Rzewuska, Magdalena; Czopowicz, Michał; Gawryś, Marta; Markowska-Daniel, Iwona; Bielecki, Wojciech

    2016-07-01

    Trueperella pyogenes is an opportunistic pathogen causing suppurative infections in livestock and wild animals. Although this bacterium is known for a long time, our knowledge about its pathogenicity is still insufficient. In this study the relationships between antimicrobial resistance profiles, distribution of virulence factor genes and the origin of T. pyogenes isolates were investigated. Isolates (n = 97) from various infections in domestic animals and European bison were studied. Minimal inhibitory concentrations of 12 antimicrobials were determined by a strip diffusion method, and PCR was used for detection of genes encoding seven putative virulence factors. All strains were susceptible to tested beta-lactams, and a statistically significant correlation between the resistance to enrofloxacin, tetracycline, macrolides, clindamycin, and a strain origin was found. The isolates from European bison were more susceptible than those from livestock, however the resistance to tetracycline and fluoroquinolones was observed. The plo and fimA genes were detected in all strains. There was no statistically significant association between the distribution of particular virulence factor genes and the type of infection, but the nanH, nanP and fimG genes were less frequently found in the isolates from European bison. The presence of three genes, nanP, nanH and cbpA, was found to be related to the resistance to tetracycline and ciprofloxacin. In conclusion, the resistance patterns of T. pyogenes were correlated with an isolate origin, but our findings did not allow to indicate which of the putative virulence factors may play a crucial role in the pathogenesis of particular types of T. pyogenes infection. PMID:27154538

  16. [Temporal and Spatial Distribution of Environmental Factors and Phytoplankton During Algal Bloom Season in Pengxi River, Three Gorges Reservoir].

    PubMed

    Zhou, Chuan; Yu, Jian-jun; Fu, Li; Cui, Yu-jie; Liu, De-fu; Jiang, Wei; Haffner, Douglas; Zhang, Lei

    2016-03-15

    Planktonic algae and Related Environmental Factors were monitored during the period of algal blooms season in 2014 (Spring April 17 and summer 27 July) in Pengxi river, Three Gorges Reservoir. Mathematical statistical tools were used to analyze the community structure of planktonic algae in Pengxi River with its environmental factors. The results of sampling in spring showed that except the estuary site, S1 and the site close by, S2, the waters stratified, but without epilimnion, only had metalimnion and hypolimnion; the upstream sites had larger temperature difference between water layers than did the downstream ones; from all the 8 sampling sites from estuary to upstream, water depth, and the temperature, pH, conductivity, dissolved oxygen, chlorophyll a, TN and TP of the surface layer (0-0.5 m deep) were significantly different (ANOVA, P < 0.05). 25 species (genus) of planktonic algae were identified. The abundance of species ranged from 2.76 x 10⁴ cell · L⁻¹ to 145.8 x 10⁴ cell · L⁻¹. Ceratium hirundinella was the main dominant species, and Anabaena sp. was the sub-dominant species. Algal bloom in upstream sampling sites S7 (63.4 x 10⁴cell · L⁻¹) and S8 (145.8 x 10⁴cell · L⁻¹)were relatively serious in spring. Temperature of water, pH , conductivity, dissolved oxygen and NO₃⁻ were the key regulatory factors for phytoplankton abundance based on redundancy analysis ( RDA). The results of sampling in summer showed similar stratification trends among sites; the depth of the same 8 sampling sites, and their surface layer's temperature of water, turbidity, redox potential, pH, water depth, conductivity, chlorophyll a, NH₄⁺, NO₃⁻, total nitrogen and total phosphorus were significantly different (ANOVA, P < 0.05). 46 species (genus) of phytoplanktonic algae were identified. The abundance ranged from 9.56 x 10⁴ cell · L⁻¹ to 278.88 x 10⁴ cell · L⁻¹. Phormidium sp. was the main dominant species, and Anabaena sp. was the sub

  17. Exploring the distribution of food stores in British Columbia: associations with neighbourhood socio-demographic factors and urban form.

    PubMed

    Black, Jennifer L; Carpiano, Richard M; Fleming, Stuart; Lauster, Nathanael

    2011-07-01

    Several studies have identified disparities in access to food retailers among urban neighbourhoods with varied socio-demographic characteristics; but few studies have examined whether key zoning and siting mechanisms described in the urban planning literature explain differences in food store access. This study assessed associations between socio-demographic and urban planning variables with the availability of large supermarkets and stores selling fresh food within one kilometre buffers from residential addresses and the proximity to the closest food stores across 630 census tracts in British Columbia, Canada. Multivariate regression results indicated that neighbourhoods with higher median household income had significantly decreased access to food stores. Inclusion of urban planning factors in multivariate models, particularly housing and transportation considerations, explained much of the relation between area income and food store access, and were significant predictors of food store availability and proximity. Public health research and practice addressing food availability would benefit by incorporating theoretical perspectives from urban planning theory. PMID:21565544

  18. Energy factors and temperature distribution in insulated built-up roofs. Technical note July 1977-January 1980

    SciTech Connect

    Keeton, J.R.; Alumbaugh, R.L.

    1981-02-01

    Surface temperatures of 4-ply built-up roofs insulated with (1) 1 inch of perlite (R = 2.8) and 2-1/2 inches of urethane (R = 19.2) and (2) 1 inch of urethane (R = 7.1) and 1-7/8 inches of glass fiber (R = 7.7) are presented. Energy factors are shown in terms of temperature-time areas defined as solar heat response, cooling (heating) required, radiative cooling, and insulation efficiency. Results indicate that for a black surface, solar heat response is significantly higher in the roof portion with the higher R-value. Solar heat response is directly affected by color of surfacing; lowest to highest values were found with white, white gravel, gray gravel, aluminum-gray, and black. Recommendations are given for reducing surface temperatures of insulated built-up roofs.

  19. Von Willebrand factor is reversibly decreased during torpor in 13-lined ground squirrels.

    PubMed

    Cooper, Scott; Sell, Shawn; Nelson, Luke; Hawes, Jennifer; Benrud, Jacob A; Kohlnhofer, Bridget M; Burmeister, Bradley R; Flood, Veronica H

    2016-01-01

    During torpor in a hibernating mammal, decreased blood flow increases the risk of blood clots such as deep vein thrombi (DVT). In other animal models platelets, neutrophils, monocytes and von Willebrand factor (VWF) have been found in DVT. Previous research has shown that hibernating mammals decrease their levels of platelets and clotting factors VIII (FVIII) and IX (FIX), increasing both bleeding time and activated partial thromboplastin time. In this study, FVIII, FIX and VWF activities and mRNA levels were measured in torpid and non-hibernating ground squirrels (Ictidomys tridecemlineatus). Here, we show that VWF high molecular weight multimers, collagen-binding activity, lung mRNA and promoter activity decrease during torpor. The VWF multimers reappear in plasma within 2 h of arousal in the spring. Similarly, FIX activity and liver mRNA both dropped threefold during torpor. In contrast, FVIII liver mRNA levels increased twofold while its activity dropped threefold, consistent with a post-transcriptional decrease in FVIII stability in the plasma due to decreased VWF levels. Finally, both neutrophils and monocytes are decreased eightfold during torpor which could slow the formation of DVT. In addition to providing insight in how blood clotting can be regulated to allow mammals to survive in extreme environments, hibernating ground squirrels provide an interesting model for studying. PMID:26481634

  20. Diagnostic Value of Measuring Platelet Von Willebrand Factor in Von Willebrand Disease

    PubMed Central

    Casonato, Alessandra; Cattini, Maria Grazia; Daidone, Viviana; Pontara, Elena; Bertomoro, Antonella; Prandoni, Paolo

    2016-01-01

    Von Willebrand disease (VWD) may be caused by an impaired von Willebrand factor (VWF) synthesis, its increased clearance or abnormal function, or combinations of these factors. It may be difficult to recognize the different contributions of these anomalies. Here we demonstrate that VWD diagnostics gains from measuring platelet VWF, which can reveal a defective VWF synthesis. Measuring platelet VWF revealed that: severe type 1 VWD always coincided with significantly lower platelet and plasma VWF levels, whereas mild forms revealed low plasma VWF levels associated with low or normal platelet VWF levels, and the latter were associated with a slightly shorter VWF survival; type Vicenza (the archetype VWD caused by a reduced VWF survival) featured normal platelet VWF levels despite significantly reduced plasma VWF levels; type 2B patients could have either normal platelet VWF levels associated with abnormal multimer patterns, or reduced platelet VWF levels associated with normal multimer patterns; type 2A patients could have reduced or normal platelet VWF levels, the former associated mainly with type 2A-I, the latter with type 2A-II; plasma and platelet VWF levels were normal in type 2N, except when the defect was associated with a quantitative VWF mutation. Our findings show that measuring platelet VWF helps to characterize VWD, especially the ambiguous phenotypes, shedding light on the mechanisms underlying the disorder. PMID:27532107

  1. Visceral adiposity and its anatomical distribution as predictors of the metabolic syndrome and cardiometabolic risk factor levels

    PubMed Central

    Demerath, Ellen W; Reed, Derek; Rogers, Nikki; Sun, Shumei S; Lee, Miryoung; Choh, Audrey C; Couch, William; Czerwinski, Stefan A; Chumlea, W Cameron; Siervogel, Roger M; Towne, Bradford

    2009-01-01

    Background Despite the recognition that central obesity plays a critical role in chronic disease, few large-scale imaging studies have documented human variation in abdominal adipose tissue patterning. Objective We aimed to compare the associations between abdominal subcutaneous adipose tissue (ASAT) and visceral abdominal tissue (VAT), which were measured at different locations across the abdomen, and the presence of the metabolic syndrome (MS; National Cholesterol Education Program Adult Treatment Panel III definition) and individual cardiometabolic risk factors. Design This study included 713 non-Hispanic whites aged 18–86 y, in whom VAT and ASAT were assessed by using multiple-image magnetic resonance imaging. The anatomical position of the magnetic resonance image containing the maximum VAT area for each subject was used as a measure of VAT patterning. Multivariate linear and logistic regression analyses were used to examine the relation of VAT, ASAT, and VAT patterning to cardiometabolic risk. Results VAT mass was a stronger predictor of the MS than was ASAT mass, but ASAT mass (and other measures of subcutaneous adiposity) had signification interactions with VAT mass, whereby elevated ASAT reduced the probability of MS among men with high VAT (P = 0.0008). There was variation across image locations in the association of VAT area with the MS in men, and magnetic resonance images located 4–8 cm above L4–L5 provided the strongest correlations between VAT area and cardiometabolic risk factors. Subjects whose maximum VAT area was higher in the abdomen had higher LDL-cholesterol concentrations (R2 = 0.07, P = 0.0001), independent of age and adiposity. Conclusion Further studies are needed to confirm the effects of VAT patterning on cardiometabolic risk. PMID:18996861

  2. Teat apex colonization with coagulase-negative Staphylococcus species before parturition: Distribution and species-specific risk factors.

    PubMed

    De Visscher, A; Piepers, S; Haesebrouck, F; De Vliegher, S

    2016-02-01

    Coagulase-negative staphylococci (CNS) are the main cause of bovine intramammary infections and are also abundantly present in extramammary habitats such as teat apices. Teat apex colonization (TAC) with CNS has already been explored in lactating dairy cows at the species level, whereas this is not true for dry cows and end-term heifers. Therefore, the aim of this observational study was to describe CNS TAC in nonlactating dairy cows and end-term heifers in Flemish dairy herds and to identify associated risk factors at the herd, cow, and quarter level. All CNS were molecularly identified to the species level using transfer RNA intergenic spacer PCR (tDNA-PCR) and sequencing of the 16S rRNA gene, allowing for species-specific statistical analyses using multivariable, multilevel logistic regression. Staphylococcus devriesei, Staphylococcus chromogenes, Staphylococcus haemolyticus, and Staphylococcus equorum were the most frequently isolated species. Staphylococcus chromogenes was the sole species colonizing teat apices of cows and heifers in all herds, whereas large between-herd differences were observed for the other species. Teat apices of red and white Holstein Friesians, of quarters dried off without an internal teat sealer, and swabbed in months with lower precipitation and higher ambient temperature were significantly more likely to be colonized by S. devriesei. Slightly dirty teat apices and teat apices swabbed in months with lower precipitation had higher odds of being colonized by S. chromogenes, whereas teat apices sampled in months with lower precipitation and higher ambient temperature were more likely to be colonized by S. haemolyticus. Dirty teat apices and teat apices swabbed in months with lower ambient temperature in combination with low precipitation had higher odds of being colonized by S. equorum. Diverse factors explaining CNS TAC, yet mostly related to humidity, ambient temperature, and hygiene, substantiate differences in epidemiological

  3. Spatially governed climate factors dominate management in determining the quantity and distribution of soil organic carbon in dryland agricultural systems

    PubMed Central

    Hoyle, Frances C.; O’Leary, Rebecca A.; Murphy, Daniel V.

    2016-01-01

    Few studies describe the primary drivers influencing soil organic carbon (SOC) stocks and the distribution of carbon (C) fractions in agricultural systems from semi-arid regions; yet these soils comprise one fifth of the global land area. Here we identified the primary drivers for changes in total SOC and associated particulate (POC), humus (HOC) and resistant (ROC) organic C fractions for 1347 sample points in the semi-arid agricultural region of Western Australia. Total SOC stock (0–0.3 m) varied from 4 to 209 t C ha−1 with 79% of variation explained by measured variables. The proportion of C in POC, HOC and ROC fractions averaged 28%, 45% and 27% respectively. Climate (43%) and land management practices (32%) had the largest relative influence on variation in total SOC. Carbon accumulation was constrained where average daily temperature was above 17.2 °C and annual rainfall below 450 mm, representing approximately 42% of the 197,300 km2 agricultural region. As such large proportions of this region are not suited to C sequestration strategies. For the remainder of the region a strong influence of management practices on SOC indicate opportunities for C sequestration strategies associated with incorporation of longer pasture phases and adequate fertilisation. PMID:27530805

  4. Factors that affect molecular weight distribution of Suwannee river fulvic acid as determined by electrospray ionization/mass spectrometry

    USGS Publications Warehouse

    Rostad, C.E.; Leenheer, J.A.

    2004-01-01

    Effects of methylation, molar response, multiple charging, solvents, and positive and negative ionization on molecular weight distributions of aquatic fulvic acid were investigated by electrospray ionization/mass spectrometry. After preliminary analysis by positive and negative modes, samples and mixtures of standards were derivatized by methylation to minimize ionization sites and reanalyzed.Positive ionization was less effective and produced more complex spectra than negative ionization. Ionization in methanol/water produced greater response than in acetonitrile/water. Molar response varied widely for the selected free acid standards when analyzed individually and in a mixture, but after methylation this range decreased. After methylation, the number average molecular weight of the Suwannee River fulvic acid remained the same while the weight average molecular weight decreased. These differences are probably indicative of disaggregation of large aggregated ions during methylation. Since the weight average molecular weight decreased, it is likely that aggregate formation in the fulvic acid was present prior to derivatization, rather than multiple charging in the mass spectra. ?? 2004 Elsevier B.V. All rights reserved.

  5. Spatially governed climate factors dominate management in determining the quantity and distribution of soil organic carbon in dryland agricultural systems.

    PubMed

    Hoyle, Frances C; O'Leary, Rebecca A; Murphy, Daniel V

    2016-01-01

    Few studies describe the primary drivers influencing soil organic carbon (SOC) stocks and the distribution of carbon (C) fractions in agricultural systems from semi-arid regions; yet these soils comprise one fifth of the global land area. Here we identified the primary drivers for changes in total SOC and associated particulate (POC), humus (HOC) and resistant (ROC) organic C fractions for 1347 sample points in the semi-arid agricultural region of Western Australia. Total SOC stock (0-0.3 m) varied from 4 to 209 t C ha(-1) with 79% of variation explained by measured variables. The proportion of C in POC, HOC and ROC fractions averaged 28%, 45% and 27% respectively. Climate (43%) and land management practices (32%) had the largest relative influence on variation in total SOC. Carbon accumulation was constrained where average daily temperature was above 17.2 °C and annual rainfall below 450 mm, representing approximately 42% of the 197,300 km(2) agricultural region. As such large proportions of this region are not suited to C sequestration strategies. For the remainder of the region a strong influence of management practices on SOC indicate opportunities for C sequestration strategies associated with incorporation of longer pasture phases and adequate fertilisation. PMID:27530805

  6. Spatial distribution of bacterial communities driven by multiple environmental factors in a beach wetland of the largest freshwater lake in China

    PubMed Central

    Ding, Xia; Peng, Xiao-Jue; Jin, Bin-Song; Xiao, Ming; Chen, Jia-Kuan; Li, Bo; Fang, Chang-Ming; Nie, Ming

    2015-01-01

    The spatial distributions of bacterial communities may be driven by multiple environmental factors. Thus, understanding the relationships between bacterial distribution and environmental factors is critical for understanding wetland stability and the functioning of freshwater lakes. However, little research on the bacterial communities in deep sediment layers exists. In this study, thirty clone libraries of 16S rRNA were constructed from a beach wetland of the Poyang Lake along both horizontal (distance to the water-land junction) and vertical (sediment depth) gradients to assess the effects of sediment properties on bacterial community structure and diversity. Our results showed that bacterial diversity increased along the horizontal gradient and decreased along the vertical gradient. The heterogeneous sediment properties along gradients substantially affected the dominant bacterial groups at the phylum and species levels. For example, the NH+4 concentration decreased with increasing depth, which was positively correlated with the relative abundance of Alphaproteobacteria. The changes in bacterial diversity and dominant bacterial groups showed that the top layer had a different bacterial community structure than the deeper layers. Principal component analysis revealed that both gradients, not each gradient independently, contributed to the shift in the bacterial community structure. A multiple linear regression model explained the changes in bacterial diversity and richness along the depth and distance gradients. Overall, our results suggest that spatial gradients associated with sediment properties shaped the bacterial communities in the Poyang Lake beach wetland. PMID:25767466

  7. Influence of Topographic and Hydrographic Factors on the Spatial Distribution of Leptospirosis Disease in São Paulo County, Brazil: An Approach Using Geospatial Techniques and GIS Analysis

    NASA Astrophysics Data System (ADS)

    Ferreira, M. C.; Ferreira, M. F. M.

    2016-06-01

    Leptospirosis is a zoonosis caused by Leptospira genus bacteria. Rodents, especially Rattus norvegicus, are the most frequent hosts of this microorganism in the cities. The human transmission occurs by contact with urine, blood or tissues of the rodent and contacting water or mud contaminated by rodent urine. Spatial patterns of concentration of leptospirosis are related to the multiple environmental and socioeconomic factors, like housing near flooding areas, domestic garbage disposal sites and high-density of peoples living in slums located near river channels. We used geospatial techniques and geographical information system (GIS) to analysing spatial relationship between the distribution of leptospirosis cases and distance from rivers, river density in the census sector and terrain slope factors, in Sao Paulo County, Brazil. To test this methodology we used a sample of 183 geocoded leptospirosis cases confirmed in 2007, ASTER GDEM2 data, hydrography and census sectors shapefiles. Our results showed that GIS and geospatial analysis techniques improved the mapping of the disease and permitted identify the spatial pattern of association between location of cases and spatial distribution of the environmental variables analyzed. This study showed also that leptospirosis cases might be more related to the census sectors located on higher river density areas and households situated at shorter distances from rivers. In the other hand, it was not possible to assert that slope terrain contributes significantly to the location of leptospirosis cases.

  8. Prevalence, Genotype Distribution and Risk Factors for Cervical Human Papillomavirus Infection in the Grand Tunis Region, Tunisia.

    PubMed

    Ardhaoui, Monia; Ennaifer, Emna; Letaief, Hajer; Salsabil, Rejaibi; Lassili, Thalja; Chahed, Karim; Bougatef, Souha; Bahrini, Asma; El Fehri, Emna; Ouerhani, Kaouther; Paez Jimenez, Adela; Guizani, Ikram; Boubaker, Med Samir; Ben Alaya, Nissaf Bouafif Ép

    2016-01-01

    Implementation of Human Papillomavirus (HPV) vaccination should be considered a key cervical cancer prevention strategy in Tunisia, where Pap smear screening is not efficient. This study aims to estimate the prevalence and to identify risk factors associated with HPV infection among women from Grand Tunis, Tunisia. We conducted a cross-sectional study, between December 2012 and May 2013. Eligible women for this study were those aged 18-65 years, sexually active, who sought medical attention at their primary health care centre or clinic in Grand Tunis, Tunisia and who gave written consent. A liquid-based Pap smear sample was obtained from all women using a cervical brush. Only women with betaglobin positive test were further analysed for HPV detection and typing. A nested-PCR of the L1 region was performed followed by reverse line blot hybridization to facilitate the specific detection of 31 HPV genotypes. Multiple logistic regression modeling was used for the analysis of associations between variables with some considered possible confounders after checking for interactions. A total of 391 women were enrolled in this study and 325 out of the 391 cervical samples were positive for the betaglobin test. Overall HPV prevalence was 13.2% [9.8%-17.5%], with the following most prevalent HPV genotypes: HPV6 (40%), HPV40 (14%), HPV16 (12%), HPV52 (9%), HPV31 and HPV59 (7%), followed by HPV68 (4%). Mean age of HPV positive women was 40.7±0.92 years. Independently associated risk factors of HPV infection were smoking (OR:2.8 [0.8-9.6]), low income (OR:9.6 [1.4-63.4), bad housing type (OR:2.5 [1-6.8]), partner with multiple sexual relationship (OR:4.5 [0.9-22.9]) and single women (widowed, divorced, separated, never married) (OR:6.9 [1.1-42.2]). This study provides the first national-based estimate of HPV prevalence in Tunisia. Our findings contribute to the evidence on the current burden of HPV infection, the critical role of sexual behaviour and socioeconomic status and

  9. Prevalence, Genotype Distribution and Risk Factors for Cervical Human Papillomavirus Infection in the Grand Tunis Region, Tunisia

    PubMed Central

    Ennaifer, Emna; Letaief, Hajer; Salsabil, Rejaibi; Lassili, Thalja; Chahed, Karim; Bougatef, Souha; Bahrini, Asma; El Fehri, Emna; Ouerhani, Kaouther; Paez Jimenez, Adela; Guizani, Ikram; Boubaker, Med Samir; Ben Alaya, Nissaf Bouafif ép

    2016-01-01

    Implementation of Human Papillomavirus (HPV) vaccination should be considered a key cervical cancer prevention strategy in Tunisia, where Pap smear screening is not efficient. This study aims to estimate the prevalence and to identify risk factors associated with HPV infection among women from Grand Tunis, Tunisia. We conducted a cross-sectional study, between December 2012 and May 2013. Eligible women for this study were those aged 18–65 years, sexually active, who sought medical attention at their primary health care centre or clinic in Grand Tunis, Tunisia and who gave written consent. A liquid-based Pap smear sample was obtained from all women using a cervical brush. Only women with betaglobin positive test were further analysed for HPV detection and typing. A nested-PCR of the L1 region was performed followed by reverse line blot hybridization to facilitate the specific detection of 31 HPV genotypes. Multiple logistic regression modeling was used for the analysis of associations between variables with some considered possible confounders after checking for interactions. A total of 391 women were enrolled in this study and 325 out of the 391 cervical samples were positive for the betaglobin test. Overall HPV prevalence was 13.2% [9.8%−17.5%], with the following most prevalent HPV genotypes: HPV6 (40%), HPV40 (14%), HPV16 (12%), HPV52 (9%), HPV31 and HPV59 (7%), followed by HPV68 (4%). Mean age of HPV positive women was 40.7±0.92 years. Independently associated risk factors of HPV infection were smoking (OR:2.8 [0.8–9.6]), low income (OR:9.6 [1.4–63.4), bad housing type (OR:2.5 [1–6.8]), partner with multiple sexual relationship (OR:4.5 [0.9–22.9]) and single women (widowed, divorced, separated, never married) (OR:6.9 [1.1–42.2]). This study provides the first national-based estimate of HPV prevalence in Tunisia. Our findings contribute to the evidence on the current burden of HPV infection, the critical role of sexual behaviour and socioeconomic

  10. Amount, determining factors and spatial distribution of soil organic carbon storage in the Dano catchment (Southwest Burkina-Faso)

    NASA Astrophysics Data System (ADS)

    Hounkpatin, O.; Op de Hipt, F.; Bossa, A. Y.; Welp, G.; Amelung, W.

    2015-12-01

    The ability to project and to mitigate the impacts of climate change is closely related to the evaluation of soil organic carbon (SOC) content and stock across different types of land use and soil groups. Therefore, this study aimed at estimating the surface and subsoil organic carbon stocks in different land use systems and across various soil groups. A further aim was to assess the spatial variability of SOC content and stocks and how this is controlled by climate and site properties. The Random Forest (RF) modelling was used and compared to Ordinary Kriging interpolation (OK) for the topsoil SOC and stock. About 70 soil profiles were described along 16 transects with 197 samples collected from different horizons up to 1 m depth where possible. In addition, 1205 samples were collected within an intensive auger grid mapping. Mid-infrared spectroscopy and partial least-squares analysis were used as a fast and low-cost technique to handle the large amount of samples for the SOC estimation. The natural/semi natural vegetation recorded the highest SOC stock in the topsoil (28.6 t C ha-1) as compared to the cropland (25.5 t C ha-1). Over 1 m depth, Gleysols (87.4 t C ha-1) stored the highest amount of SOC stock followed by the Cambisols (76. t C ha-1) and the Plinthosols (73.1 t C ha-1) while the lowest were found in the Lixisols (57.8 t C ha-1). For the topsoil, the RF model revealed soil properties such as cation exchange capacity (CEC) and stone content as main factors affecting SOC content variability while CEC and bulk density were the major drivers for the subsoil. The carbon stock variability was mainly affected by the CEC and the reference soil group in the topsoil while horizon thickness and bulk density constituted the main factors for the subsoil. The geostatistical evaluation proved that the SOC content in the Dano catchment has a moderate spatial autocorrelation while the carbon stock was strongly spatially dependent. The RF gave a better prediction for

  11. Ecological factors responsible for the geographic distribution of Rhabdias joaquinensis: where do lungworms infect anurans in nature?

    PubMed

    Langford, Gabriel J; Janovy, John

    2016-03-01

    The lungworm Rhabdias joaquinensis (Nematoda: Rhabdiasidae) is a common parasite of anurans in eastern Nebraska, yet absent from the same hosts in western Nebraska. This study investigated the ecology of the lungworm's free-living stages that reside in host feces and surrounding soils to establish the worm's free-living niche in eastern Nebraska. Using a comparative method, this study also investigated the absence of lungworms in western Nebraska's Sandhills. Soil composition, moisture, and temperature were experimentally varied in the laboratory to assess their effects on juvenile development and survival. Field mesocosm and host defecation experiments were used to determine where in nature lungworms survive and eventually infect frogs and toads and to discover if vegetation facilitates lungworm transmission to hosts. The results found loam soils were amenable to lungworm development, whereas soils with high clay or sand content produced few infective lungworms. Soil moisture <50 % did not support lungworm development. Infective juveniles successfully developed between 5 and 35 °C, albeit at different rates, whereas only a limited number of non-infective worms developed at 40 °C. Field studies found that shoreline environments supported lungworm development, and the majority of lungworm infections appear to occur within a zone of infection adjacent to shorelines in eastern Nebraska. The prevalence in vegetation mesocosms was 100 %, and a significantly higher mean abundance was found in toads from containers with vegetation than without. Overall, these experiments suggest that the spatial distribution of R. joaquinensis in Nebraska is constrained by the worm's ability to survive and reproduce in a soil matrix. PMID:26666887

  12. Factors influencing the distribution of Myxobolus cerebralis, the causative agent of whirling disease, in the Cache la Poudre River, Colorado

    USGS Publications Warehouse

    Allen, M. Brady; Bergersen, Eric P.

    2002-01-01

    Oligochaetes, triactinomyxons (TAMs), and age-0 trout were sampled in the upper Cache la Poudre River, Colorado, to determine the distribution of Myxobolus cerebralis during 1997 and 1998. Densities of the intermediate host, the oligochaete Tubifex tubifex, were 3.5 orders of magnitude higher in the M. cerebralis-infected Poudre Rearing Unit (PRU) trout rearing ponds than at any of the river sampling reaches. Oligochaetes, including T. tubifex, were rare in the river (1 oligochaete m-2), except in a few stream side alcoves and eddies (50 oligochaete m-2). Species composition of oligochaetes in the river reaches was more diverse than in the PRU. Tubifex tubifex constituted 50% or less of the oligochaete community in the river and 98% in the PRU. Infection rates of T. tubifex were 1% in the area above the PRU, 2% in the PRU, and 6% below the PRU. An increased M. cerebralis intensity of infection in age-0 trout below the PRU could not be attributed entirely to the high numbers of TAMs in its effluent (3.7 TAMs l-1). Low densities of TAMs ranging from 0 to 0.2 TAMs l-1 were found in the river reaches, yet nearly all of the age-0 trout were infected soon after emergence. This suggests that very few TAMs, as measured by filtration, need be present in the water column to bring about infection in the majority of trout present. This also indicates that the parasite can persist and potentially cause reduced juvenile trout recruitment in cold, oligotrophic, sediment poor, high-gradient streams.

  13. Investigation of factors affecting the accumulation of vinyl chloride in polyvinyl chloride piping used in drinking water distribution systems.

    PubMed

    Walter, Ryan K; Lin, Po-Hsun; Edwards, Marc; Richardson, Ruth E

    2011-04-01

    Plastic piping made of polyvinyl chloride (PVC), and chlorinated PVC (CPVC), is being increasingly used for drinking water distribution lines. Given the formulation of the material from vinyl chloride (VC), there has been concern that the VC (a confirmed human carcinogen) can leach from the plastic piping into drinking water. PVC/CPVC pipe reactors in the laboratory and tap samples collected from consumers homes (n = 15) revealed vinyl chloride accumulation in the tens of ng/L range after a few days and hundreds of ng/L after two years. While these levels did not exceed the EPA's maximum contaminant level (MCL) of 2 μg/L, many readings that simulated stagnation times in homes (overnight) exceeded the MCL-Goal of 0 μg/L. Considerable differences in VC levels were seen across different manufacturers, while aging and biofilm effects were generally small. Preliminary evidence suggests that VC may accumulate not only via chemical leaching from the plastic piping, but also as a disinfection byproduct (DBP) via a chlorine-dependent reaction. This is supported from studies with CPVC pipe reactors where chlorinated reactors accumulated more VC than dechlorinated reactors, copper pipe reactors that accumulated VC in chlorinated reactors and not in dechlorinated reactors, and field samples where VC levels were the same before and after flushing the lines where PVC/CPVC fittings were contributing. Free chlorine residual tests suggest that VC may be formed as a secondary, rather than primary, DBP. Further research and additional studies need to be conducted in order to elucidate reaction mechanisms and tease apart relative contributions of VC accumulation from PVC/CPVC piping and chlorine-dependent reactions. PMID:21420710

  14. Presentation of the Multimédia Game "Geolover" Concept, to Educational Enchancement of the Geolocical Heritage of the Following Regions: "Ilha do Fogo" (Cabo-Verde), Seridó (Brasil), Sabugal (Portugal) and Açores (Portugal)

    NASA Astrophysics Data System (ADS)

    Cabral, João; Gomes, Ana; Alfama, Vera; Oliveira, Sirlene; Pinharandas, Carlos; Fonseca, Pedro; Campos, José; Nobre, José

    2013-04-01

    "Geolover" - Presentation of the multimédia game concept, to educational enchancement of the geolocical heritage of the following regions: : "Ilha do Fogo" (Cabo-Verde), Seridó (Brasil), Sabugal and Açores (Portugal). "Geolover" is a multitouch game, played by four players simultaneously, identified by 4 mascots and using as sceneries, the four regions landscapes, aimed to the young people with ages between 8 and 12 years old. The main objective is value the geological heritage of the Ilha do Fogo (Cabo Verde), Seridó in State of Rio Grande do Norte (Brasil) , Sabugal in Beira Alta province (Portugal) and Arquipélago dos Açores (Portuguese autonomous region). These regions have a great geological heritage like volcanology, plutonic rocks, sedimentar formations, metamorphic, paleontologic, mineralogic, geomorphologic, hydric and mining resources. Such heritage is being used in the different regions has base of studies to senior scientists and were used to great scientific researches. The diversified and distinguished cultural heritage of these four regions is referenced and it's a value to the union of the students from these three continents, with the Portuguese language as communication tool. The variety of the geological wealth and cultural of these regions, results in the common objective of their valuing like Geoparks. His creation on these three regions is a strategy with a great relevance to the socio-economic development. With the creation of this game, we promote the union of these 3 countries from these three continents, the universal values of the heritage richness that are offered by our planet.

  15. Spatial patterns of distribution and the influence of seasonal and abiotic factors on demersal ichthyofauna in an estuarine tropical bay.

    PubMed

    da Silva, D R; Paranhos, R; Vianna, M

    2016-07-01

    This study focused on the influence of local-scale environmental factors on key metrics of fish community structure and function at Guanabara Bay, an estuarine system that differs from all other south-western Atlantic estuaries due to the influence of an annual low-intensity upwelling event during late spring and summer, between November and March, when a warm rainy climate prevails. The spatial patterns of the bottom temperature and salinity were more heterogeneous during the rainy season than the dry season, being linked to total precipitation and seasonal oceanographic events. The study identified 130 species and 45 families, placing Guanabara Bay as one of the most species-rich tropical estuarine ecosystems, far exceeding 22 other Brazilian estuaries. These results, in addition to characteristics such as a relatively well-preserved mangrove forest, high productivity and favourable conditions for the growth and reproduction of estuarine species, indicate that Guanabara Bay plays a central role in supporting large populations of fishes, including commercially important species. PMID:27401484

  16. Evaluate the frequency distribution of nonadhesive virulence factors in carbapenemase-producing Acinetobacter baumannii isolated from clinical samples in Kermanshah

    PubMed Central

    Mohajeri, Parviz; Sharbati, Saba; Farahani, Abbas; Rezaei, Zhaleh

    2016-01-01

    Background: Acinetobacter baumannii which is a Gram-negative bacterium can cause several different infections. The appearance of carbapenemase-producing A. baumannii in recent years has made the treatment process more difficult. The identification of virulence factors (VFs), such as nonadhesives in A. baumannii, helps to fight against related infections. Materials and Methods: A total of 104 samples from teaching hospitals in Kermanshah, Iran, were collected during a 24 months period (2011-2013). Sample identification was first carried out by biochemical tests, and then their susceptibility to carbapenems was determined using the Kirby–Bauer method. For confirmation of carbapenemase-producing A. baumannii, polymerase chain reaction (PCR) was done for carbapenemase-encoding genes. In addition, the frequency of nonadhesive VFs in carbapenemase-producing isolates was determined by PCR. Results: There were 50 isolates that were identified as carbapenemase-producing A. baumannii. The PCR results showed; 40 isolates (80%) for traT, 17 isolates (34%) for cvaC, and 8 isolates (16%) for iutA, and these encode serum resistance, colicin V and aerobactin, respectively. No significant correlation was observed between these three genes. Conclusions: The mechanism of A. baumannii virulence has always been in question. The role of VFs has also been recognized in other Gram-negative bacteria. According to the prevalence of traT, cvaC and iutA, as nonadhesive VFs, we can suggest that they could be the main mechanism of carbapenemase-producing A. baumannii pathogenesis. PMID:27003971

  17. Human and canine visceral leishmaniasis in an emerging focus in Araçuaí, Minas Gerais: spatial distribution and socio-environmental factors

    PubMed Central

    Ursine, Renata Luiz; Dias, João Victor Leite; Morais, Harriman Aley; Pires, Herton Helder Rocha

    2016-01-01

    This study aimed to analyse the spatial distribution of human (2007-2013) and canine (2013) visceral leishmaniasis (VL) in the city of Araçuaí, Minas Gerais, Brazil, and identify the socio-environmental factors related to their occurrence. The spatial distribution of human and canine cases was analysed by kernel density estimation (KDE) and the K function. The KDE values were analysed for correlation between human and canine LV and for normalised difference vegetation index (NDVI). Socio-environmental aspects of household structures and surroundings were evaluated. The spatial distribution of human and canine VL cases exhibited a significant aggregated pattern in distances greater than 350 and 75 m, respectively. The higher occurrence of human and canine infection occurred in the central area of the city. A positive correlation between the densities of human and canine cases was observed, as well as a negative correlation between NDVI and densities of human and canine cases. Socio-environmental analysis revealed that the large amount of animals, organic material from trees and deficiencies in environmental sanitation are possibly contributing to the continuation of the transmission cycle of Leishmania infantum in Araçuaí. These results can contribute to the planning by competent agencies to reduce the incidence of infection in the city. PMID:27384080

  18. Translationally Invariant Calculations of Form Factors, Densities and Momentum Distributions for Finite Nuclei with Short-Range Correlations Included: A Fresh Look

    NASA Astrophysics Data System (ADS)

    Shebeko, A.; Grigorov, P.; Iurasov, V.

    2014-08-01

    The approach proposed in the 70s (Dementiji et al. in Sov J Nucl Phys 22:6-9, 1976), when describing the elastic and inelastic electron scattering off 4 He, and elaborated in (Shebeko et al.in Eur Phys J A27:143-155, 2006) for calculations of the one-body, two-body and more complex density matrices of finite bound systems has been applied (Shebeko and Grigorov in Ukr J Phys 52:830-842, 2007; Shebeko et al. in Eur. Phys. J. A48:153-172, 2012) in studying a combined effect of the center-of-mass motion and nucleon-nucleon short-range correlations on the nucleon density and momentum distributions in light nuclei beyond the independent particle model. Unlike a common practice, suitable for infinite bound systems, these distributions are determined as expectation values of appropriate intrinsic operators that depend upon the relative coordinates and momenta (Jacobi variables) and act on the intrinsic ground-state wave functions (WFs). The latter are constructed in the so-called fixed center-of-mass approximation, starting with a mean-field Slater determinant modified by some correlator (e.g., after Jastrow or Villars). Our numerical calculations of the charge form factors ( F CH ( q)), densities and momentum distributions have been carried out for nuclei 4 He and 16 O choosing, respectively, the 1 s and 1 s-1 p Slater determinants of the harmonic oscillator model as trial, nontranslationally invariant WFs.

  19. Satellite-derived NDVI, LST, and climatic factors driving the distribution and abundance of Anopheles mosquitoes in a former malarious area in northwest Argentina.

    PubMed

    Dantur Juri, María Julia; Estallo, Elizabet; Almirón, Walter; Santana, Mirta; Sartor, Paolo; Lamfri, Mario; Zaidenberg, Mario

    2015-06-01

    Distribution and abundance of disease vectors are directly related to climatic conditions and environmental changes. Remote sensing data have been used for monitoring environmental conditions influencing spatial patterns of vector-borne diseases. The aim of this study was to analyze the effect of the Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST) obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS), and climatic factors (temperature, humidity, wind velocity, and accumulated rainfall) on the distribution and abundance of Anopheles species in northwestern Argentina using Poisson regression analyses. Samples were collected from December, 2001 to December, 2005 at three localities, Aguas Blancas, El Oculto and San Ramón de la Nueva Orán. We collected 11,206 adult Anopheles species, with the major abundance observed at El Oculto (59.11%), followed by Aguas Blancas (22.10%) and San Ramón de la Nueva Orán (18.79%). Anopheles pseudopunctipennis was the most abundant species at El Oculto, Anopheles argyritarsis predominated in Aguas Blancas, and Anopheles strodei in San Ramón de la Nueva Orán. Samples were collected throughout the sampling period, with the highest peaks during the spring seasons. LST and mean temperature appear to be the most important variables determining the distribution patterns and major abundance of An. pseudopunctipennis and An. argyritarsis within malarious areas. PMID:26047182

  20. Deep-sea macroplankton distribution (at 400 to 2300 m) in the northwestern Mediterranean in relation to environmental factors

    NASA Astrophysics Data System (ADS)

    Cartes, J. E.; Fanelli, E.; López-Pérez, C.; Lebrato, M.

    2013-03-01

    Changes in the composition and biomass distribution of deep-living zooplankton over wide gradients of depth (400-2300 m) and longitude (~ 180 km) have been analyzed in the Balearic Basin (western Mediterranean), seeking the environmental variables responsible for these changes. Zooplankton tends to aggregate at different levels of the water column (forming Deep Scattering Layers, DSL) and in the Benthic Boundary Layer (BBL). Macrozooplankton biomass and composition were analyzed along a transect performed in July 2010 in midwater (between ~ 350 and 450 m) and near the bottom (at ~ 5-200 mab), over soundings of 450-2263 m, including the top of Valencia Seamount (at ~ 40° 25' N-02° 42' E, 1076 m). Zooplankton changed significantly in composition at the mesoscale (~ 180 km) in both the DSL and the BBL. Siphonophores and calanoid copepods were the most dominant deep zooplankton taxa, calanoids reaching higher abundance in the BBL (1761-5177 individuals/1000 m3) than in the DSL (1568-1743 individuals/1000 m3). There was a significant increase in near-bottom zooplankton biomass over the middle slope, at 1000-1300 m, linked to an increase in scyphozoans and siphonophores (Lensia spp. and Abylopsis tetragona) with peaks of 1.5-2.0 gWW/1000 m3. The peak of near-bottom zooplankton at 1000-1300 m coincided with the lowest temperatures (13.08 °C) and maximum O2 concentration (4.40 ml/l) near the bottom and below 1000 m with higher records in near-bottom turbidity. Gelatinous zooplankton are the main prey in the diet of the demersal fish Alepocephalus rostratus in the western Mediterranean, fish responsible for the peak of megafauna biomass reported at around 1200-1400 m in the deep Mediterranean and at similar depths in other oceanic areas (e.g. the NW Atlantic). We suggest that deep-sea environmental conditions can govern peaks of near-bottom zooplankton, as well as influence the structure of the demersal fish community.

  1. Distribution and Chemical Coding of Corticotropin Releasing Factor-Immunoreactive Neurons in the Guinea-Pig Enteric Nervous System

    PubMed Central

    Liu, Sumei; Gao, Na; Hu, Hong-Zhen; Wang, Xiyu; Wang, Guo-Du; Fang, Xiucai; Gao, Xiang; Xia, Yun; Wood, Jackie D.

    2008-01-01

    Immunofluorescence was used to study immunoreactivity (IR) for corticotropin releasing factor (CRF) in the guinea-pig enteric nervous system. CRF-IR was expressed in both the myenteric and submucosal plexuses of all regions of the large and small intestine and the myenteric plexus of the stomach. CRF-IR-nerve fibers were present in the myenteric and submucosal plexuses, in the circular muscle coat and surrounding submucosal arterioles. Most of the CRF-IR fibers persisted in the myenteric and submucosal plexuses after 7 days in organotypic culture. CRF-IR was not co-expressed with tyrosine hydroxylase-IR or calcitonin gene-related peptide-IR fibers. The proportions of CRF-IR cell bodies in the myenteric plexus increased progressively from the stomach (0.6%) to the distal colon (2.8%). Most of the CRF-IR myenteric neurons (95%) had uniaxonal morphology; the remainder had Dogiel type II multipolar morphology. CRF-IR cell bodies in the myenteric plexus of the ileum expressed IR for choline acetyltransferase (56.9%), substance P (55.0%), and nitric oxide synthase (37.9%). CRF-IR never co-localized with IR for calbindin, calretinin, neuropeptide Y, serotonin or somatostatin in the myenteric plexus. CRF-IR cell bodies were more abundant in the submucosal plexus (29.9-38.0%) than in the myenteric plexus. All CRF-IR neurons in submucosal ganglia expressed vasoactive intestinal peptide-IR and were likely to be secretomotor/vasodilator neurons. CRF-IR neurons did not express IR for the CRF1 receptor. CRF1-IR was expressed in neuronal neighbors of those with CRF-IR. Collective evidence suggests that VIPergic secretomotor neurons might provide synaptic input to neighboring cholinergic neurons. PMID:16304680

  2. Impact of Real-world Factors Influencing Investment Decisions on the Costs and Distribution of Climate Change Mitigation

    NASA Astrophysics Data System (ADS)

    Edmonds, J.; Iyer, G.; McJeon, H. C.; Leon, C.; Hultman, N.

    2015-12-01

    Strategies to mitigate dangerous anthropogenic climate change require a dramatic transformation of the energy system to reduce greenhouse gas emissions, that in turn requires large-scale investments. Investment decisions depend not only on investment capital availability but also on investment risks. A number of factors such as national policy environments, quality of public and private institutions, sector, firm and technology specific characteristics can affect investors' assessments of risks, leading to a wide variation in the business climate for investment. Such heterogeneity in investment risks can have important implications, as investors usually respond to risks by requiring higher returns for riskier projects; delaying or forgoing the investments; or preferring to invest in existing, familiar projects. We study the impact of variation in investment risks on regional patterns of emissions mitigation, the cost of emissions mitigation and patterns of technology deployment. We modify an integrated assessment model, widely used in global climate policy analyses (the Global Change Assessment Model) and incorporate decisions on investments based on risks along two dimensions. Along the first dimension, we vary perceived risks associated with particular technologies. To do so, we assign a higher cost of capital for investment in low-carbon technologies as these involve intrinsically higher levels of regulatory and market risk. The second dimension uses a proxy to vary investment risks across regions, based on an institutional quality metric published by the World Economic Forum. Explicit representation of investment risks has two major effects. First, it raises the cost of emissions mitigation relative to a world with uniform investment risks. Second, it shifts the pattern of emissions mitigation, with industrialized countries mitigating more, and developing countries mitigating less. Our results suggest that institutional reforms aimed at lowering investment

  3. Spatially distributed influence of agro-environmental factors governing nitrate fate and transport in an irrigated stream-aquifer system

    NASA Astrophysics Data System (ADS)

    Bailey, R. T.; Ahmadi, M.; Gates, T. K.; Arabi, M.

    2015-12-01

    Elevated levels of nitrate (NO3) in groundwater systems pose a serious risk to human populations and natural ecosystems. As part of an effort to remediate NO3 contamination in irrigated stream-aquifer systems, this study elucidates agricultural and environmental parameters and processes that govern NO3 fate and transport at the regional (500 km2), local (50 km2), and field scales (< 1 km2). Specifically, the revised Morris sensitivity analysis method was applied to a finite-difference nitrogen cycling and reactive transport model of a regional-scale study site in the lower Arkansas River valley in southeastern Colorado. The method was used to rank the influence of anthropogenic activities and natural chemical processes on NO3 groundwater concentration, NO3 mass leaching, and NO3 mass loading to the Arkansas River from the aquifer. Sensitivity indices were computed for the entire study area in aggregate as well as each canal command area, crop type, and individual grid cells. Results suggest that fertilizer loading, crop uptake, and heterotrophic denitrification govern NO3 fate and transport for the majority of the study area, although their order of influence on NO3 groundwater concentration and mass leaching varies according to crop type and command area. Canal NO3 concentration and rates of autotrophic denitrification, nitrification, and humus decomposition also dominate or partially dominate in other locations. Each factor, with the exception of O2 reduction rate, is the dominating influence on NO3 groundwater concentration at one or more locations within the study area. Results can be used to determine critical processes and key management actions for future data collection and remediation strategies, with efforts able to be focused on localized areas.

  4. Distribution of granulocyte-monocyte colony-stimulating factor and its receptor α-subunit in the adult human brain with specific reference to Alzheimer's disease.

    PubMed

    Ridwan, Sami; Bauer, Henrike; Frauenknecht, Katrin; von Pein, Harald; Sommer, Clemens J

    2012-11-01

    Granulocyte-monocyte colony-stimulating factor (GM-CSF) is a member of the hematopoietic growth factor family, promoting proliferation and differentiation of hematopoietic progenitor cells of the myeloid lineage. In recent years, GM-CSF has also proved to be an important neurotrophic factor in the central nervous system (CNS) via binding to the GM-CSF receptor (GM-CSF R). Furthermore, studies on rodent CNS revealed a wide distribution of both the major binding α-subunit of the GM-CSF R (GM-CSF Rα) and its ligand. Since respective data on the expression pattern of these two molecules are still lacking, the present study has been designed to systematically analyze the protein expression of GM-CSF and GM-CSF Rα in the human brain, with particular emphasis on their regulation in Alzheimer's disease (AD). One major finding is that both GM-CSF and GM-CSF Rα were ubiquitously but not uniformly expressed in neurons throughout the CNS. Protein expression of GM-CSF and GM-CSF Rα was not restricted to neurons but also detectable in astrocytes, ependymal cells and choroid plexus cells. Interestingly, distribution and intensity of immunohistochemical staining for GM-CSF did not differ among AD brains and age-matched controls. Concerning GM-CSF Rα, a marked reduction of protein expression was predominantly detected in the hippocampus although a slight reduction was also found in various cortical regions, thalamic nuclei and some brainstem nuclei. Since the hippocampus is one of the target regions of neurodegenerative changes in AD, reduction of GM-CSF Rα, with consecutive downregulation of GM-CSF signaling, may contribute to in the progressive course of neurodegeneration in AD. PMID:22430742

  5. The influence of fuel mass load, oxygen supply and burning rate on emission factor and size distribution of carbonaceous particulate matter from indoor corn straw burning

    PubMed Central

    Shen, Guofeng; Xue, Miao; Wei, Siye; Chen, Yuanchen; Wang, Bing; Wang, Rong; Shen, Huizhong; Li, Wei; Zhang, Yanyan; Huang, Ye; Chen, Han; Wei, Wen; Zhao, Qiuyue; Li, Bin; Wu, Haisuo; Tao, Shu

    2014-01-01

    The uncertainty in emission estimation is strongly associated with the variation in emission factor which could be influenced by a variety of factors, like fuel property, stove type, fire management and even methods used in measurements. The impacts of these factors were usually complicated and often interacted with each other. In the present study, controlled burning experiments were conducted to investigate the influence of fuel mass load, air supply and burning rate on the emission of carbonaceous particulate matter (PM) from indoor corn straw burning. Their impacts on PM size distribution were also studied. The results showed that EFs of PM (EFPM), organic carbon (EFOC) and element carbon (EFEC) was independent of the fuel mass load. The differences among them under different burning rates or air supply amounts were also found to be insignificant (p > 0.05) in the tested circumstances. PM from the indoor corn straw burning was dominated by fine PM, and PM with diameter less than 2.1 μm contributed about 86.4±3.9% of the total. The size distribution of PM was also influenced by the burning rate and changed air supply conditions. On average, EFPM, EFOC and EFEC for corn straw burned in a residential cooking stove were 3.84±1.02, 0.846±0.895 and 0.391±0.350 g/kg, respectively. EFPM, EFOC and EFEC were found to be positively correlated with each other, but they were not significantly correlated with EF of co-emitted CO, suggesting a special attention should be paid to the use of CO acting as a surrogate for other incomplete pollutants. PMID:23923424

  6. Gender differences and lateralization in the distribution pattern of insulin-like growth factor-1 receptor in developing rat hippocampus: an immunohistochemical study.

    PubMed

    Hami, Javad; Kheradmand, Hamed; Haghir, Hossein

    2014-03-01

    Numerous investigators have provided data supporting essential roles for insulin-like growth factor-I (IGF-I) in development of the brain. The aim of this study was to immunohistochemically determine the distinct regional distribution pattern of IGF-1 receptor (IGF-IR) expression in various portions of newborn rat hippocampus on postnatal days 0 (P0), 7 (P7), and 14 (P14), with comparison between male/female and right/left hippocampi. We found an overall significant increase in distribution of IGF-IR-positive (IGF-IR+) cells in CA1 from P0 until P14. Although, no marked changes in distribution of IGF-IR+ cells in areas CA2 and CA3 were observed; IGF-IR+ cells in DG decreased until P14. The smallest number of immunoreactive cells was present in CA2 and the highest number in DG at P0. Moreover, in CA1, CA3, and DG, the number of IGF-IR+ cells was markedly higher in both sides of the hippocampus in females. Our data also showed a higher mean number of IGF-IR+ cells in the left hippocampus of female at P7. By contrast, male pups showed a significantly higher number of IGF-IR+ cells in the DG of the right hippocampus. At P14, the mean number of immunoreactive cells in CA1, CA3, and DG areas found to be significantly increased in left side of hippocampus of males, compared to females. These results indicate the existence of a differential distribution pattern of IGF-IR between left-right and male-female hippocampi. Together with other mechanisms, these differences may underlie sexual dimorphism and left-right asymmetry in the hippocampus. PMID:24287499

  7. Factors affecting the occurrence of saugers in small, high-elevation rivers near the western edge of the species' natural distribution

    USGS Publications Warehouse

    Amadio, C.J.; Hubert, W.A.; Johnson, K.; Oberlie, D.; Dufek, D.

    2005-01-01

    Factors affecting the occurrence of saugers Sander canadensis were studied throughout the Wind River basin, a high-elevation watershed (> 1,440 m above mean sea level) on the western periphery of the species' natural distribution in central Wyoming. Adult saugers appeared to have a contiguous distribution over 170 km of streams among four rivers in the watershed. The upstream boundaries of sauger distribution were influenced by summer water temperatures and channel slopes in two rivers and by water diversion dams that created barriers to upstream movement in the other two rivers. Models that included summer water temperature, maximum water depth, habitat type (pool or run), dominant substrate, and alkalinity accounted for the variation in sauger occurrence across the watershed within the areas of sauger distribution. Water temperature was the most important basin-scale habitat feature associated with sauger occurrence, and maximum depth was the most important site-specific habitat feature. Saugers were found in a larger proportion of pools than runs in all segments of the watershed and occurred almost exclusively in pools in upstream segments of the watershed. Suitable summer water temperatures and deep, low-velocity habitat were available to support saugers over a large portion of the Wind River watershed. Future management of saugers in the Wind River watershed, as well as in other small river systems within the species' native range, should involve (1) preserving natural fluvial processes to maintain the summer water temperatures and physical habitat features needed by saugers and (2) assuring that barriers to movement do not reduce upstream boundaries of populations.

  8. Presence and distribution of mosquito larvae predators and factors influencing their abundance along the Mara River, Kenya and Tanzania.

    PubMed

    Dida, Gabriel O; Gelder, Frank B; Anyona, Douglas N; Abuom, Paul O; Onyuka, Jackson O; Matano, Ally-Said; Adoka, Samson O; Kanangire, Canisius K; Owuor, Philip O; Ouma, Collins; Ofulla, Ayub Vo

    2015-01-01

    .001). Understanding abiotic and biotic factors which favour mosquitoes and macroinveterbrate co-occurrence may contribute to the control of malaria. PMID:25830082

  9. Distribution of algae in the San Joaquin River, California, in relation to nutrient supply, salinity and other environmental factors

    USGS Publications Warehouse

    Leland, H.V.; Brown, L.R.; Mueller, D.K.

    2001-01-01

    1. The taxonomic composition and biomass of the phytoplankton and the taxonomic composition of the phytobenthos of the San Joaquin River and its major tributaries were examined in relation to water chemistry, habitat and flow regime. Agricultural drainage and subsurface flow contribute to a complex gradient of salinity and nutrients in this eutrophic, 'lowland type' river. 2. Because of light-limiting conditions for growth, maintenance demands of the algae exceed production during summer and autumn in the San Joaquin River where there is no inflow from tributaries. In contrast to substantial gains in concentration of inorganic nitrogen and soluble reactive phosphorus during the summer of normal-flow years, net losses of algal biomass (2-4 ??g L-1 day-1 chlorophyll a) occurred in a mid-river segment with no significant tributary inflow. However, downstream of a large tributary draining the Sierra Nevada, a substantial net gain in algal biomass (6-11 ??g L-1 day-1) occurred in the summer, but not in the spring (loss of 1-6 ??g L-1 day-1) or autumn (loss of 2-5 ??g L-1 day-1). 3. The phytoplankton was dominated in summer by 'r-selected' centric diatoms (Thalassiosirales), species both tolerant of variable salinity and widely distributed in the San Joaquin River. Pennate diatoms were proportionally more abundant (in biomass) in the winter, spring and autumn. Abundant taxa included the diatoms Cyclotella meneghiniana, Skeletonema cf. potamos, Cyclostephanos invisitatus, Thalassiosira weissflogii, Nitzschia acicularis, N. palea and N. reversa, and the chlorophytes Chlamydomonas sp. and Scenesdesmus quadricauda. Patterns in the abundance of species indicated that assembly of the phytoplankton is limited more by light and flow regime than by nutrient supply. 4. The phytobenthos was dominated by larger, more slowly reproducing pennate diatoms. Few of the abundant species are euryhaline. The diatoms Navicula recens and Nitzschia inconspicua and cyanophytes, Oscillatoria spp

  10. Environmental factors affecting the distribution of land snails in the Atlantic Rain Forest of Ilha Grande, Angra dos Reis, RJ, Brazil.

    PubMed

    Nunes, G K M; Santos, S B

    2012-02-01

    The distribution and abundance of terrestrial molluscs are affected by environmental factors, but data are lacking for Brazilian land snails. The aim of this study was to understand the relationship between measured environmental factors and the land-snail species composition of two hillsides covered with Atlantic Rain Forest on Ilha Grande. On each hillside, five plots located at 100 m intervals between 100 to 500 m asl were chosen. Each plot was sampled by carrying out timed searches and collecting and sorting litter samples from ten quadrats of 25 × 75 cm. A range of environmental data was measured for each of the quadrats in a plot. A Cluster Analysis was carried out for the richness and abundance data. The environmental variables were analysed using a Pearson Correlation Matrix and Discriminant Analysis. Our results show that the two mountains are similar in species richness, but species composition and abundance are different, probably reflecting observed differences in environmental conditions. The environmental factors associated with compositional variation between the two mountains were: atmospheric temperature, soil temperature, litter depth, and relative air humidity. Distinct luminosity and canopy closure conditions were related to the composition of the land-snail community of one hillside. PMID:22437388

  11. Associations Between Macrolevel Economic Factors and Weight Distributions in Low- and Middle-Income Countries: A Multilevel Analysis of 200 000 Adults in 40 Countries

    PubMed Central

    Sweet, Elizabeth; Kawachi, Ichiro; Heymann, Jody; Galea, Sandro

    2014-01-01

    Objectives. We examined associations between macrolevel economic factors hypothesized to drive changes in distributions of weight and body mass index (BMI) in a representative sample of 200 796 men and women from 40 low- and middle-income countries. Methods. We used meta-regressions to describe ecological associations between macrolevel factors and mean BMIs across countries. Multilevel regression was used to assess the relation between macrolevel economic characteristics and individual odds of underweight and overweight relative to normal weight. Results. In multilevel analyses adjusting for individual-level characteristics, a 1–standard-deviation increase in trade liberalization was associated with 13% (95% confidence interval [CI] = 0.76, 0.99), 17% (95% CI = 0.71, 0.96), 13% (95% CI = 0.76, 1.00), and 14% (95% CI = 0.75, 0.99) lower odds of underweight relative to normal weight among rural men, rural women, urban men, and urban women, respectively. Economic development was consistently associated with higher odds of overweight relative to normal weight. Among rural men, a 1–standard-deviation increase in foreign direct investment was associated with 17% (95% CI = 1.02, 1.35) higher odds of overweight relative to normal weight. Conclusions. Macrolevel economic factors may be implicated in global shifts in epidemiological patterns of weight. PMID:24228649

  12. Quantification of perioperative changes in von Willebrand factor and factor VIII during elective orthopaedic surgery in normal individuals

    PubMed Central

    Kahlon, A.; Grabell, J.; Tuttle, A.; Engen, D.; Hopman, W.; Lillicrap, D.; James, P.

    2014-01-01

    Summary von Willebrand’s disease (VWD) patients undergoing major surgery are prophylactically treated to promote haemostasis. There is variability in perioperative clinical practice; however, most guidelines suggest replacing the deficient factor to a level of 1.0 IU mL−1 (or 100%). A review of the literature reveals a paucity of well constructed descriptive data quantifying the changes in coagulation that occur in response to surgical stress. The aim of this study was to quantify the changes in haemostatic variables occurring in response to elective orthopaedic surgery in normal individuals. Eligible subjects >18 years of age undergoing total hip or knee replacement were recruited. Blood samples were drawn at five time points: baseline, preoperatively, 30 min after surgical incision, 30 min postoperatively, postoperative day (POD) 1. Analyses included t-tests and repeated measures anova. Overall 30 patients, 21 women and 9 men, with a mean age of 65 were included in the final analysis. All von Willebrand factor (VWF) variables were seen to significantly decrease intraoperatively and increase postoperatively. VWF multimers showed a statistically significant decrease in high molecular weight multimers intraoperatively and an increase postoperatively. On subgroup analysis, age, gender and anaesthesia type were significantly correlated with changes in VWF parameters. Data presented in the current study establish a physiological baseline for VWF parameters in the normal population and demonstrate mean VWF/factor VIII levels greater than 1.0 IU mL−1 intraoperatively. As such, current management in VWD patients does not appear to mimic the normal physiological response to surgery. PMID:23711418

  13. Force sensing by the vascular protein von Willebrand factor is tuned by a strong intermonomer interaction.

    PubMed

    Müller, Jochen P; Mielke, Salomé; Löf, Achim; Obser, Tobias; Beer, Christof; Bruetzel, Linda K; Pippig, Diana A; Vanderlinden, Willem; Lipfert, Jan; Schneppenheim, Reinhard; Benoit, Martin

    2016-02-01

    The large plasma glycoprotein von Willebrand factor (VWF) senses hydrodynamic forces in the bloodstream and responds to elevated forces with abrupt elongation, thereby increasing its adhesiveness to platelets and collagen. Remarkably, forces on VWF are elevated at sites of vascular injury, where VWF's hemostatic potential is important to mediate platelet aggregation and to recruit platelets to the subendothelial layer. Adversely, elevated forces in stenosed vessels lead to an increased risk of VWF-mediated thrombosis. To dissect the remarkable force-sensing ability of VWF, we have performed atomic force microscopy (AFM)-based single-molecule force measurements on dimers, the smallest repeating subunits of VWF multimers. We have identified a strong intermonomer interaction that involves the D4 domain and critically depends on the presence of divalent ions, consistent with results from small-angle X-ray scattering (SAXS). Dissociation of this strong interaction occurred at forces above [Formula: see text]50 pN and provided [Formula: see text]80 nm of additional length to the elongation of dimers. Corroborated by the static conformation of VWF, visualized by AFM imaging, we estimate that in VWF multimers approximately one-half of the constituent dimers are firmly closed via the strong intermonomer interaction. As firmly closed dimers markedly shorten VWF's effective length contributing to force sensing, they can be expected to tune VWF's sensitivity to hydrodynamic flow in the blood and to thereby significantly affect VWF's function in hemostasis and thrombosis. PMID:26787887

  14. Force sensing by the vascular protein von Willebrand factor is tuned by a strong intermonomer interaction

    PubMed Central

    Müller, Jochen P.; Mielke, Salomé; Löf, Achim; Obser, Tobias; Beer, Christof; Bruetzel, Linda K.; Pippig, Diana A.; Vanderlinden, Willem; Lipfert, Jan; Schneppenheim, Reinhard; Benoit, Martin

    2016-01-01

    The large plasma glycoprotein von Willebrand factor (VWF) senses hydrodynamic forces in the bloodstream and responds to elevated forces with abrupt elongation, thereby increasing its adhesiveness to platelets and collagen. Remarkably, forces on VWF are elevated at sites of vascular injury, where VWF’s hemostatic potential is important to mediate platelet aggregation and to recruit platelets to the subendothelial layer. Adversely, elevated forces in stenosed vessels lead to an increased risk of VWF-mediated thrombosis. To dissect the remarkable force-sensing ability of VWF, we have performed atomic force microscopy (AFM)-based single-molecule force measurements on dimers, the smallest repeating subunits of VWF multimers. We have identified a strong intermonomer interaction that involves the D4 domain and critically depends on the presence of divalent ions, consistent with results from small-angle X-ray scattering (SAXS). Dissociation of this strong interaction occurred at forces above ∼50 pN and provided ∼80 nm of additional length to the elongation of dimers. Corroborated by the static conformation of VWF, visualized by AFM imaging, we estimate that in VWF multimers approximately one-half of the constituent dimers are firmly closed via the strong intermonomer interaction. As firmly closed dimers markedly shorten VWF’s effective length contributing to force sensing, they can be expected to tune VWF’s sensitivity to hydrodynamic flow in the blood and to thereby significantly affect VWF’s function in hemostasis and thrombosis. PMID:26787887

  15. Human tumor necrosis factor alpha gene regulation by virus and lipopolysaccharide.

    PubMed Central

    Goldfeld, A E; Doyle, C; Maniatis, T

    1990-01-01

    We have identified a region of the human tumor necrosis factor alpha (TNF-alpha) gene promoter that is necessary for maximal constitutive, virus-induced, and lipopolysaccharide (LPS)-induced transcription. This region contains three sites that match an NF-kappa B binding-site consensus sequence. We show that these three sites specifically bind NF-kappa B in vitro, yet each of these sites can be deleted from the TNF-alpha promoter with little effect on the induction of the gene by virus or LPS. Moreover, when multimers of these three sites are placed upstream from a truncated TNF-alpha promoter, or a heterologous promoter, an increase in the basal level of transcription is observed that is influenced by sequence context and cell type. However, these multimers are not sufficient for virus or LPS induction of either promoter. Thus, unlike other virus- and LPS-inducible promoters that contain NF-kappa B binding sites, these sites from the TNF-alpha promoter are neither required nor sufficient for virus or LPS induction. Comparison of the sequence requirements of virus induction of the human TNF-alpha gene in mouse L929 and P388D1 cells reveals significant differences, indicating that the sequence requirements for virus induction of the gene are cell type-specific. However, the sequences required for virus and LPS induction of the gene in a single cell type, P388D1, overlap. Images PMID:2263628

  16. Determination of the geometrical factor and of the spatial distributions of particles for a cosmic ray telescope using a Monte Carlo approach

    NASA Technical Reports Server (NTRS)

    Hemmer, M.; Crannell, C. J.

    1973-01-01

    A program is presented which uses a Monte Carlo technique to compute the geometrical factor of a detector, and the spatial and angular distributions of simulated particles at designated layers within the detector. As the program is written, each layer is assumed to be rectangular, parallel to every other layer with its edges parallel to the edges of every other layer, and centered about a common axis. This program is written in Fortran 4 for the IBM 360 computers and is currently being run under the Fortran 4 (h) compiler. Same features such as the subroutine ERRSET, RANDU, and REMTIM and the type declarations REAL *8 and LOGICAL *1 may need to be changed for use with a different computer system. The use of input data cards, and a sample data set are presented. Lists of the symbol definition, card images of the FORTRAN object deck and subroutines are included along with a flow diagram.

  17. Near-field-assisted localization: effect of size and filling factor of randomly distributed zinc oxide nanoneedles on multiple scattering and localization of light

    NASA Astrophysics Data System (ADS)

    Silies, Martin; Mascheck, Manfred; Leipold, David; Kollmann, Heiko; Schmidt, Slawa; Sartor, Janos; Yatsui, Takashi; Kitamura, Kokoro; Ohtsu, Motoicho; Kalt, Heinz; Runge, Erich; Lienau, Christoph

    2016-07-01

    We investigate the influence of the diameter and the filling factor of randomly arranged ZnO nanoneedles on the multiple scattering and localization of light in disordered dielectrics. Coherent, ultra-broadband second-harmonic (SH) microscopy is used to probe the spatial localization of light in representative nm-sized ZnO arrays of needles. We observe strong fluctuations of the SH intensity inside different ZnO needle geometries. Comparison of the SH intensity distributions with predictions based on a one-parameter scaling model indicate that SH fluctuations can be taken as a quantitative measure for the degree of localization. Interestingly, the strongest localization signatures are found for densely packed arrays of thin needles with diameters in the range of only 30 nm range, despite the small scattering cross section of these needles. FDTD simulations indicate that in this case coupling of electric near-fields between neighbouring needles governs the localization.

  18. Factors affecting distribution of wood, detritus, and sediment in headwater streams draining managed young-growth red alder - Conifer forests in southeast Alaska

    USGS Publications Warehouse

    Gomi, T.; Johnson, A.C.; Deal, R.L.; Hennon, P.E.; Orlikowska, E.H.; Wipfli, M.S.

    2006-01-01

    Factors (riparian stand condition, management regimes, and channel properties) affecting distributions of wood, detritus (leaves and branches), and sediment were examined in headwater streams draining young-growth red alder (Alnus rubra Bong.) - conifer riparian forests (40 years old) remained in channels and provided sites for sediment and organic matter storage. Despite various alder-conifer mixtures and past harvesting effects, the abundance of large wood, fine wood, and detritus accumulations significantly decreased with increasing channel bank-full width (0.5-3.5 m) along relatively short channel distances (up to 700 m). Changes in wood, detritus, and sediment accumulations together with changes in riparian stand characteristics create spatial and temporal variability of in-channel conditions in headwater systems. A component of alder within young-growth riparian forests may benefit both wood production and biological recovery in disturbed headwater stream channels. ?? 2006 NRC.

  19. Transverse momentum distribution and nuclear modification factor of charged particles in p+Pb collisions at sqrt[s(NN)] = 5.02 TeV.

    PubMed

    Abelev, B; Adam, J; Adamová, D; Adare, A M; Aggarwal, M M; Aglieri Rinella, G; Agnello, M; Agocs, A G; Agostinelli, A; Ahammed, Z; Ahmad, N; Ahmad Masoodi, A; Ahn, S A; Ahn, S U; Ajaz, M; Akindinov, A; Aleksandrov, D; Alessandro, B; Alici, A; Alkin, A; Almaráz Aviña, E; Alme, J; Alt, T; Altini, V; Altinpinar, S; Altsybeev, I; Andrei, C; Andronic, A; Anguelov, V; Anielski, J; Anson, C; Antičić, T; Antinori, F; Antonioli, P; Aphecetche, L; Appelshäuser, H; Arbor, N; Arcelli, S; Arend, A; Armesto, N; Arnaldi, R; Aronsson, T; Arsene, I C; Arslandok, M; Asryan, A; Augustinus, A; Averbeck, R; Awes, T C; Aystö, J; Azmi, M D; Bach, M; Badalà, A; Baek, Y W; Bailhache, R; Bala, R; Baldini Ferroli, R; Baldisseri, A; Baltasar Dos Santos Pedrosa, F; Bán, J; Baral, R C; Barbera, R; Barile, F; Barnaföldi, G G; Barnby, L S; Barret, V; Bartke, J; Basile, M; Bastid, N; Basu, S; Bathen, B; Batigne, G; Batyunya, B; Baumann, C; Bearden, I G; Beck, H; Behera, N K; Belikov, I; Bellini, F; Bellwied, R; Belmont-Moreno, E; Bencedi, G; Beole, S; Berceanu, I; Bercuci, A; Berdnikov, Y; Berenyi, D; Bergognon, A A E; Berzano, D; Betev, L; Bhasin, A; Bhati, A K; Bhom, J; Bianchi, L; Bianchi, N; Bielčík, J; Bielčíková, J; Bilandzic, A; Bjelogrlic, S; Blanco, F; Blanco, F; Blau, D; Blume, C; Boccioli, M; Böttger, S; Bogdanov, A; Bøggild, H; Bogolyubsky, M; Boldizsár, L; Bombara, M; Book, J; Borel, H; Borissov, A; Bossú, F; Botje, M; Botta, E; Braidot, E; Braun-Munzinger, P; Bregant, M; Breitner, T; Browning, T A; Broz, M; Brun, R; Bruna, E; Bruno, G E; Budnikov, D; Buesching, H; Bufalino, S; Buncic, P; Busch, O; Buthelezi, Z; Caballero Orduna, D; Caffarri, D; Cai, X; Caines, H; Calvo Villar, E; Camerini, P; Canoa Roman, V; Cara Romeo, G; Carena, W; Carena, F; Carlin Filho, N; Carminati, F; Casanova Díaz, A; Castillo Castellanos, J; Castillo Hernandez, J F; Casula, E A R; Catanescu, V; Cavicchioli, C; Ceballos Sanchez, C; Cepila, J; Cerello, P; Chang, B; Chapeland, S; Charvet, J L; Chattopadhyay, S; Chattopadhyay, S; Chawla, I; Cherney, M; Cheshkov, C; Cheynis, B; Chibante Barroso, V; Chinellato, D D; Chochula, P; Chojnacki, M; Choudhury, S; Christakoglou, P; Christensen, C H; Christiansen, P; Chujo, T; Chung, S U; Cicalo, C; Cifarelli, L; Cindolo, F; Cleymans, J; Coccetti, F; Colamaria, F; Colella, D; Collu, A; Conesa Balbastre, G; Conesa Del Valle, Z; Connors, M E; Contin, G; Contreras, J G; Cormier, T M; Corrales Morales, Y; Cortese, P; Cortés Maldonado, I; Cosentino, M R; Costa, F; Cotallo, M E; Crescio, E; Crochet, P; Cruz Alaniz, E; Cuautle, E; Cunqueiro, L; Dainese, A; Dalsgaard, H H; Danu, A; Das, I; Das, D; Das, K; Das, S; Dash, A; Dash, S; De, S; de Barros, G O V; De Caro, A; de Cataldo, G; de Cuveland, J; De Falco, A; De Gruttola, D; Delagrange, H; Deloff, A; De Marco, N; Dénes, E; De Pasquale, S; Deppman, A; Erasmo, G D; de Rooij, R; Diaz Corchero, M A; Di Bari, D; Dietel, T; Di Giglio, C; Di Liberto, S; Di Mauro, A; Di Nezza, P; Divià, R; Djuvsland, O; Dobrin, A; Dobrowolski, T; Dönigus, B; Dordic, O; Driga, O; Dubey, A K; Dubla, A; Ducroux, L; Dupieux, P; Dutta Majumdar, A K; Dutta Majumdar, M R; Elia, D; Emschermann, D; Engel, H; Erazmus, B; Erdal, H A; Espagnon, B; Estienne, M; Esumi, S; Evans, D; Eyyubova, G; Fabris, D; Faivre, J; Falchieri, D; Fantoni, A; Fasel, M; Fearick, R; Fehlker, D; Feldkamp, L; Felea, D; Feliciello, A; Fenton-Olsen, B; Feofilov, G; Fernández Téllez, A; Ferretti, A; Festanti, A; Figiel, J; Figueredo, M A S; Filchagin, S; Finogeev, D; Fionda, F M; Fiore, E M; Floris, M; Foertsch, S; Foka, P; Fokin, S; Fragiacomo, E; Francescon, A; Frankenfeld, U; Fuchs, U; Furget, C; Fusco Girard, M; Gaardhøje, J J; Gagliardi, M; Gago, A; Gallio, M; Gangadharan, D R; Ganoti, P; Garabatos, C; Garcia-Solis, E; Garishvili, I; Gerhard, J; Germain, M; Geuna, C; Gheata, M; Gheata, A; Ghosh, P; Gianotti, P; Girard, M R; Giubellino, P; Gladysz-Dziadus, E; Glässel, P; Gomez, R; Ferreiro, E G; González-Trueba, L H; González-Zamora, P; Gorbunov, S; Goswami, A; Gotovac, S; Graczykowski, L K; Grajcarek, R; Grelli, A; Grigoras, C; Grigoras, A; Grigoriev, V; Grigoryan, S; Grigoryan, A; Grinyov, B; Grion, N; Gros, P; Grosse-Oetringhaus, J F; Grossiord, J-Y; Grosso, R; Guber, F; Guernane, R; Guerra Gutierrez, C; Guerzoni, B; Guilbaud, M; Gulbrandsen, K; Gulkanyan, H; Gunji, T; Gupta, A; Gupta, R; Haaland, O; Hadjidakis, C; Haiduc, M; Hamagaki, H; Hamar, G; Han, B H; Hanratty, L D; Hansen, A; Harmanová-Tóthová, Z; Harris, J W; Hartig, M; Harton, A; Hasegan, D; Hatzifotiadou, D; Hayashi, S; Hayrapetyan, A; Heckel, S T; Heide, M; Helstrup, H; Herghelegiu, A; Herrera Corral, G; Herrmann, N; Hess, B A; Hetland, K F; Hicks, B; Hippolyte, B; Hori, Y; Hristov, P; Hřivnáčová, I; Huang, M; Humanic, T J; Hwang, D S; Ichou, R; Ilkaev, R; Ilkiv, I; Inaba, M; Incani, E; Innocenti, G M; Innocenti, P G; Ippolitov, M; Irfan, M; Ivan, C; Ivanov, A; Ivanov, M; Ivanov, V; Ivanytskyi, O; Jachołkowski, A; Jacobs, P M; Jang, H J; Janik, M A; Janik, R; Jayarathna, P H S Y; Jena, S; Jha, D M; Jimenez Bustamante, R T; Jones, P G; Jung, H; Jusko, A; Kaidalov, A B; Kalcher, S; Kaliňák, P; Kalliokoski, T; Kalweit, A; Kang, J H; Kaplin, V; Karasu Uysal, A; Karavichev, O; Karavicheva, T; Karpechev, E; Kazantsev, A; Kebschull, U; Keidel, R; Khan, S A; Khan, P; Khan, K H; Khan, M M; Khanzadeev, A; Kharlov, Y; Kileng, B; Kim, D J; Kim, T; Kim, D W; Kim, J H; Kim, J S; Kim, M; Kim, M; Kim, S; Kim, B; Kirsch, S; Kisel, I; Kiselev, S; Kisiel, A; Klay, J L; Klein, J; Klein-Bösing, C; Kliemant, M; Kluge, A; Knichel, M L; Knospe, A G; Köhler, M K; Kollegger, T; Kolojvari, A; Kondratiev, V; Kondratyeva, N; Konevskikh, A; Kour, R; Kovalenko, V; Kowalski, M; Kox, S; Koyithatta Meethaleveedu, G; Kral, J; Králik, I; Kramer, F; Kravčáková, A; Krawutschke, T; Krelina, M; Kretz, M; Krivda, M; Krizek, F; Krus, M; Kryshen, E; Krzewicki, M; Kucheriaev, Y; Kugathasan, T; Kuhn, C; Kuijer, P G; Kulakov, I; Kumar, J; Kurashvili, P; Kurepin, A; Kurepin, A B; Kuryakin, A; Kushpil, S; Kushpil, V; 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