Modeling Sediment Trapping in a Vegetative Filter Accounting for Converging Overland Flow

Vegetative filters (VF) are used to remove sediment and other pollutants from overland flow. When modeling the hydrology of VF, it is often assumed that overland flow is planar, but our research indicates that it can be two-dimensional with converging and diverging pathways. Our hypothesis is that flow convergence will negatively influence the sediment trapping capability of VF. The objectives were to develop a two-dimensional modeling approach for estimating sediment trapping in VF and to investigate the impact of converging overland flow on sediment trapping by VF. In this study, the performance of a VF that has field-scale flow path lengths with uncontrolled flow direction was quantified using field experiments and hydrologic modeling. Simulations of water flow processes were performed using the physically based, distributed model MIKE SHE. A modeling approach that predicts sediment trapping and accounts for converging and diverging flow was developed based on the University of Kentucky sediment filtration model. The results revealed that as flow convergence increases, filter performance decreases, and the impacts are greater at higher flow rates and shorter filter lengths. Convergence that occurs in the contributing field (in-field) upstream of the buffer had a slightly greater impact than convergence that occurred in the filter (in-filter). An area-based convergence ratio was defined that relates the actual flow area in a VF to the theoretical flow area without flow convergence. When the convergence ratio was 0.70, in-filter convergence caused the sediment trapping efficiency to be reduced from 80% for the planar flow condition to 64% for the converging flow condition. When an equivalent convergence occurred in-field, the sediment trapping efficiency was reduced to 57%. Thus, not only is convergence important but the location where convergence occurs can also be important

MODELING SEDIMENT TRAPPING IN A VEGETATIVE FILTER ACCOUNTING FOR CONVERGING OVERLAND FLOW

Vegetative filters (VF) are used to remove sediment and other pollutants from overland flow. When modeling the hydrology of VF, it is often assumed that overland flow is planar, but our research indicates that it can be two-dimensional with converging and diverging pathways. Our hypothesis is that flow convergence will negatively influence the sediment trapping capability of VF. The objectives were to develop a two-dimensional modeling approach for estimating sediment trapping in VF and to investigate the impact of converging overland flow on sediment trapping by VF. In this study, the performance of a VF that has field-scale flow path lengths with uncontrolled flow direction was quantified using field experiments and hydrologic modeling. Simulations of water flow processes were performed using the physically based, distributed model MIKE SHE. A modeling approach that predicts sediment trapping and accounts for converging and diverging flow was developed based on the University of Kentucky sediment filtration model. The results revealed that as flow convergence increases, filter performance decreases, and the impacts are greater at higher flow rates and shorter filter lengths. Convergence that occurs in the contributing field (in-field) upstream of the buffer had a slightly greater impact than convergence that occurred in the filter (in-filter). An area-based convergence ratio was defined that relates the actual flow area in a VF to the theoretical flow area without flow convergence. When the convergence ratio was 0.70, in-filter convergence caused the sediment trapping efficiency to be reduced from 80% for the planar flow condition to 64% for the converging flow condition. When an equivalent convergence occurred in-field, the sediment trapping efficiency was reduced to 57%. Thus, not only is convergence important but the location where convergence occurs can also be important

High Throughput siRNA Screening Identifies Phosphatidylinositol 3-kinase Class II Alpha as Important for Production of Human Cytomegalovirus Virions.

High throughput siRNA screening is a useful methodology to identify cellular factors required for virus replication. Here we utilized a high throughput siRNA screen based on detection of a viral antigen by microscopy to interrogate cellular protein kinases and phosphatases for their importance during human cytomegalovirus (HCMV) replication, and identified the Class II Phosphatidylinositol 3-kinase PI3K-C2A as being involved in HCMV replication. Confirming this observation, infected cells treated with either pooled or individual siRNAs targeting PI3K-C2A mRNA produced approximately 10-fold less infectious virus compared to controls. Western blotting and quantitative PCR analysis of infected cells treated with siRNAs indicated that depletion of PI3K-C2A slightly reduced accumulation of late, but not immediate-early or early, viral antigens and had no appreciable effect of viral DNA synthesis. Analysis of siRNA treated cells by electron microscopy and western blotting indicated that PI3K-C2A was not required for production of viral capsids, but did lead to increased numbers of enveloped capsids in the cytoplasm that had undergone secondary envelopment and reduction of viral particles exiting the cell. Therefore, PI3K-C2A is a factor important for HCMV replication and has a role in production of HCMV virions. IMPORTANCE: There is limited information about the cellular factors required for human cytomegalovirus (HCMV) replication. Therefore, to identify proteins involved in HCMV replication we developed a methodology to conduct a high throughput siRNA screen in HCMV infected cells. From our screening data we focused our studies on the top "hit" from our screen, the lipid kinase phosphatidylinositol 3-kinase Class II Alpha (PI3K-C2A), as its role in HCMV replication was unknown. Interestingly, we found that PI3K-C2A is important for the production of HCMV virions and is involved in virion production after secondary envelopment of viral capsids, the encapsidation of HCMV capsids by a lipid bilayer that occurs before virions exit the cell

SELENIUM CONCENTRAnONS IN BLOOD OF FREE-RANGING MULE DEER IN CAUFORNIA

Abstract: Whole blood samples from 1,695 mule deer (Odocoileus hemionus) were collected from 15 geographical herd groups from 1980 to 1988, and analyzed for whole blood selenium (Se). Mean Se concentrations for each group were compared to accepted values for livestock species. Eleven groups bad mean blood Se concentrations <0.10 mg/L (deficient by livestock standards for groups of animals). Two-thirds of the groups bad fint quartile Se concentrations (Ql) that were considered seriously deficient (<0.05 mg/L). Significant (P <0.05) difference in blood Se concentrations were found for geographical location, season (reproductive phase), sex, and resident venus migratory behavior. No significant differences were detected for sub-species or age. 1be likelihood and manifestations of Se deficiency in deer, especially decreased fawn survivability, are discussed with possible explanations for predisposing influences

Deletion of SA β-Gal+ Cells Using Senolytics Improves Muscle Regeneration in Old Mice

Systemic deletion of senescent cells leads to robust improvements in cognitive, cardiovascular, and whole-body metabolism, but their role in tissue reparative processes is incompletely understood. We hypothesized that senolytic drugs would enhance regeneration in aged skeletal muscle. Young (3 months) and old (20 months) male C57Bl/6J mice were administered the senolytics dasatinib (5 mg/kg) and quercetin (50 mg/kg) or vehicle bi-weekly for 4 months. Tibialis anterior (TA) was then injected with 1.2% BaCl2 or PBS 7- or 28 days prior to euthanization. Senescence-associated β-Galactosidase positive (SA β-Gal+) cell abundance was low in muscle from both young and old mice and increased similarly 7 days following injury in both age groups, with no effect of D+Q. Most SA β-Gal+ cells were also CD11b+ in young and old mice 7- and 14 days following injury, suggesting they are infiltrating immune cells. By 14 days, SA β-Gal+/CD11b+ cells from old mice expressed senescence genes, whereas those from young mice expressed higher levels of genes characteristic of anti-inflammatory macrophages. SA β-Gal+ cells remained elevated in old compared to young mice 28 days following injury, which were reduced by D+Q only in the old mice. In D+Q-treated old mice, muscle regenerated following injury to a greater extent compared to vehicle-treated old mice, having larger fiber cross-sectional area after 28 days. Conversely, D+Q blunted regeneration in young mice. In vitro experiments suggested D+Q directly improve myogenic progenitor cell proliferation. Enhanced physical function and improved muscle regeneration demonstrate that senolytics have beneficial effects only in old mice

Mutations at positions 186 and 194 in the HA gene of the 2009 H1N1 pandemic influenza virus improve replication in cell culture and eggs

Obtaining suitable seed viruses for influenza vaccines poses a challenge for public health authorities and manufacturers. We used reverse genetics to generate vaccine seed-compatible viruses from the 2009 pandemic swine-origin influenza virus. Comparison of viruses recovered with variations in residues 186 and 194 (based on the H3 numbering system) of the viral hemagglutinin showed that these viruses differed with respect to their ability to grow in eggs and cultured cells. Thus, we have demonstrated that molecular cloning of members of a quasispecies can help in selection of seed viruses for vaccine manufacture

Elicitation of Neutralizing Antibodies Directed against CD4-Induced Epitope(s) Using a CD4 Mimetic Cross-Linked to a HIV-1 Envelope Glycoprotein

The identification of HIV-1 envelope glycoprotein (Env) structures that can generate broadly neutralizing antibodies (BNAbs) is pivotal to the development of a successful vaccine against HIV-1 aimed at eliciting effective humoral immune responses. To that end, the production of novel Env structure(s) that might induce BNAbs by presentation of conserved epitopes, which are otherwise occluded, is critical. Here, we focus on a structure that stabilizes Env in a conformation representative of its primary (CD4) receptor-bound state, thereby exposing highly conserved “CD4 induced” (CD4i) epitope(s) known to be important for co-receptor binding and subsequent virus infection. A CD4-mimetic miniprotein, miniCD4 (M64U1-SH), was produced and covalently complexed to recombinant, trimeric gp140 envelope glycoprotein (gp140) using site-specific disulfide linkages. The resulting gp140-miniCD4 (gp140-S-S-M64U1) complex was recognized by CD4i antibodies and the HIV-1 co-receptor, CCR5. The gp140-miniCD4 complex elicited the highest titers of CD4i binding antibodies as well as enhanced neutralizing antibodies against Tier 1 viruses as compared to gp140 protein alone following immunization of rabbits. Neutralization against HIV-27312/V434M and additional serum mapping confirm the specific elicitation of antibodies directed to the CD4i epitope(s). These results demonstrate the utility of structure-based approach in improving immunogenic response against specific region, such as the CD4i epitope(s) here, and its potential role in vaccine application

ETUDE DE LA VARIABILITE GENETIQUE ET DE L'ANTIGENICITE DE LA GLYCOPROTEINE B DE L'HERPESVIRUS HUMAIN 7

L'HERPESVIRUS HUMAIN 7 (HHV-7) A ETE DECOUVERT EN 1990 DANS UNE CULTURE DE LYMPHOCYTES CD4+ PURIFIES PROVENANT D'UN SUJET SAIN. PLUS DE 90% DES SUJETS ADULTES SONT SEROPOSITIFS, LA PRIMO-INFECTION SURVIENT DANS LES PREMIERS MOIS DE LA VIE. LA VARIABILITE GENETIQUE DE L'HHV-7 EST RESTREINTE. CEPENDANT, NOUS AVONS MIS EN EVIDENCE UN POLYMORPHISME DANS LE GENE DE LA GB ET DEFINI SIX ALLELES DE CE GENE. DANS L'HYPOTHESE DE LA CLASSIFICATION DES SOUCHES D'HHV-7 EN DES GROUPES GENETIQUEMENT BIEN DEFINIS, DEUX AUTRES GENES ONT ETE ETUDIES : LE GENE DE LA P100 ET LE GENE DE LA MCP. UN POLYMORPHISME A AINSI ETE MIS EN EVIDENCE AVEC LA DESCRIPTION DE DEUX ET TROIS ALLELES RESPECTIVEMENT. L'ETUDE DES ASSOCIATIONS ENTRE ALLELES DE P100, GB ET MCP A MONTRE DEUX COMBINAISONS PREFERENTIELLES CO1 ET CO2 REPRESENTANT 72% DES SOUCHES ETUDIEES. NOUS AVONS ENTREPRIS L'ETUDE DE LA REPARTITION DE CES DIFFERENTS VARIANTS GENETIQUES DE L'HHV-7 SUR UN NOMBRE PLUS IMPORTANT D'ECHANTILLONS EN INCLUANT DES POPULATIONS HOMOGENES ANCIENNES : LES PYGMEES ET LES MONGOLS. NOUS AVONS MONTRE QUE LA COMBINAISON CO1 ETAIT PREPONDERANTE EN AFRIQUE ET EN ASIE ALORS QUE LA COMBINAISON CO2 SEMBLAIT MAJORITAIRE EN EUROPE. AINSI, NOS ETUDES EPIDEMIOLOGIQUES MOLECULAIRES SUGGERENT QUE L'HHV-7 POURRAIT ETRE UN BON OUTIL POUR L'ETUDE DES MIGRATIONS ANCIENNES DE POPULATIONS HUMAINES. EN CE QUI CONCERNE L'ETUDE DE LA GB, NOUS AVONS CLONE ET EXPRIME (I) LE GENE ENTIER DE LA GB DANS UN SYSTEME D'EXPRESSION PROCARYOTE ET (II) LA PARTIE N TERMINALE AINSI QUE LE GENE ENTIER DANS LE BACULOVIRUS. EN TESTANT 8 SERUMS HUMAINS, NOUS NOUS SOMMES APERCUS QUE LA GB ETAIT IMMUNOGENE ET QUE LA REACTIVITE DES ANTICORPS ETAIT LOCALISEE DANS LA PARTIE N-TERMINALE. PAR LA SUITE, NOUS AVONS ENTREPRIS DE FAIRE SYNTHETISER UN PEPTIDE LOCALISE DANS CETTE REGION. APRES AVOIR DETERMINE LES CONDITIONS OPTIMALES DE REACTIVITE DE CE PEPTIDE DANS UN SYSTEME ELISA, CELA NOUS A PERMIS DE TESTER DIFFERENTS SERUMS HUMAINS : 70% DES SERUMS D'ADULTES ET 85% DES SERUMS D'ENFANTS (AGES DE 6 MOIS A PLUS DE 2 ANS) SE SONT REVELES SEROPOSITIFS. ENFIN, NOUS NOUS SOMMES INTERESSES AUX ECHANTILLONS SEQUENTIELS PROVENANT DE 17 ENFANTS DE LA NAISSANCE JUSQU'A LEUR QUATRIEME ANNEE ET AVONS PU OBSERVER QUE LA SEROPOSITIVITE ETAIT DE 100% A LA NAISSANCE, CHUTAIT A 25% A 1 MOIS ET AUGMENTAIT PROGRESSIVEMENT A 100% JUSQU'A 4 ANS.PARIS-BIUSJ-Thèses (751052125) / SudocCentre Technique Livre Ens. Sup. (774682301) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Modeling Vegetative Buffer Performance Considering Topographic Data Accuracy

Riparian buffers are a promising tool in efforts to reduce sediment contribution to streams. Models that predict the capacity of buffers to trap sediment have recently been developed. A number of parameters that are required to conduct such modeling efforts are derived from the topography of the site. In this study, three topographic data sources were used to generate the model input for an agricultural field with a riparian buffer. The runoff and sediment transport in the system was then simulated for three years. As a result, the area that contributed runoff and sediment to the buffer was substantially different for each of the topographic data sources. In addition, the predicted runoff and sediment loss from the field was different for each case. Finally, the predicted sediment delivered to the stream was substantially affected by the accuracy of the topographic data source

Modeling Sediment Trapping in a Vegetative Filter Accounting for Converging Overland Flow

Vegetative filters (VF) are used to remove sediment and other pollutants from overland flow. When modeling the hydrology of VF, it is often assumed that overland flow is planar, but our research indicates that it can be two-dimensional with converging and diverging pathways. Our hypothesis is that flow convergence will negatively influence the sediment trapping capability of VF. The objectives were to develop a two-dimensional modeling approach for estimating sediment trapping in VF and to investigate the impact of converging overland flow on sediment trapping by VF. In this study, the performance of a VF that has field-scale flow path lengths with uncontrolled flow direction was quantified using field experiments and hydrologic modeling. Simulations of water flow processes were performed using the physically based, distributed model MIKE SHE. A modeling approach that predicts sediment trapping and accounts for converging and diverging flow was developed based on the University of Kentucky sediment filtration model. The results revealed that as flow convergence increases, filter performance decreases, and the impacts are greater at higher flow rates and shorter filter lengths. Convergence that occurs in the contributing field (in-field) upstream of the buffer had a slightly greater impact than convergence that occurred in the filter (in-filter). An area-based convergence ratio was defined that relates the actual flow area in a VF to the theoretical flow area without flow convergence. When the convergence ratio was 0.70, in-filter convergence caused the sediment trapping efficiency to be reduced from 80% for the planar flow condition to 64% for the converging flow condition. When an equivalent convergence occurred in-field, the sediment trapping efficiency was reduced to 57%. Thus, not only is convergence important but the location where convergence occurs can also be important.This article is from Transactions of the ASAE 48, no. 2 (2005): 514–555.</p