1,631 research outputs found

    Maximally-localized Wannier functions for entangled energy bands

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    We present a method for obtaining well-localized Wannier-like functions (WFs) for energy bands that are attached to or mixed with other bands. The present scheme removes the limitation of the usual maximally-localized WFs method (N. Marzari and D. Vanderbilt, Phys. Rev. B 56, 12847 (1997)) that the bands of interest should form an isolated group, separated by gaps from higher and lower bands everywhere in the Brillouin zone. An energy window encompassing N bands of interest is specified by the user, and the algorithm then proceeds to disentangle these from the remaining bands inside the window by filtering out an optimally connected N-dimensional subspace. This is achieved by minimizing a functional that measures the subspace dispersion across the Brillouin zone. The maximally-localized WFs for the optimal subspace are then obtained via the algorithm of Marzari and Vanderbilt. The method, which functions as a postprocessing step using the output of conventional electronic-structure codes, is applied to the s and d bands of copper, and to the valence and low-lying conduction bands of silicon. For the low-lying nearly-free-electron bands of copper we find WFs which are centered at the tetrahedral interstitial sites, suggesting an alternative tight-binding parametrization.Comment: 13 pages, with 9 postscript figures embedded. Uses REVTEX and epsf macro

    Exploring Interface Sign Ontologies for Web User Interface Design and Evaluation: A User Study

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    Part 2: Organizational Semiotics and ApplicationsInternational audienceThe aim of this paper is twofold: firstly, to find the set of ontologies (i.e., the set of concepts and skills) presupposed by users when interpreting the meaning of web interface signs (i.e., the smallest elements of web user interfaces), and secondly, to investigate users’ difficulties in interpreting the meanings of interface signs belonging to different kinds of ontologies. In order to achieve these aims an empirical user study was conducted with 26 test participants. The study data was gathered by semi-structured interviews and questionnaires. Following an empirical research approach, descriptive statistics and qualitative data analysis were used to analyze the data. The study results provide a total of twelve ontologies and reveal the users’ difficulties in interpreting the meanings of interface signs belonging to different kinds of ontologies

    Moko disease-causing strains of Ralstonia solanacearum" from Brazil extend known diversity in paraphyletic phylotype II

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    The epidemic situation of Moko disease-causing strains in Latin America and Brazil is unclear. Thirty-seven Ralstonia solanacearum strains from Brazil that cause the Moko disease on banana and heliconia plants were sampled and phylogenetically typed using the endoglucanase (egl) and DNA repair (mutS) genes according to the phylotype and sequevar classification. All of the strains belonged to phylotype II and a portion of the strains was typed as the Moko disease-related sequevars IIA-6 and IIA-24. Nevertheless, two unsuspected sequevars also harbored the Moko disease-causing strains IIA-41 and IIB-25, and a new sequevar was described and named IIA-53. All of the strains were pathogenic to banana and some of the strains of sequevars IIA-6, IIA-24, and IIA-41 were also pathogenic to tomato. The Moko disease-causing strains from sequevar IIB-25 were pathogenic to potato but not to tomato. These results highlight the high diversity of strains of Moko in Brazil, reinforce the efficiency of the egl gene to reveal relationships among these strains, and contribute to a better understanding of the diversity of paraphyletic Moko disease-causing strains of the R. solanacearum species complex, where the following seven distinct genetic clusters have been described: IIA-6, IIA-24, IIA-41, IIA-53, IIB-3, IIB-4, and IIB-25. (Résumé d'auteur

    Regional differences of testicular artery blood flow in post pubertal and pre-pubertal dogs

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    Background Measurement of testicular artery blood flow is used in several species to evaluate reproductive function and testicular and scrotal pathology. In dogs there are inconsistent reports about normal flow in post-pubertal dogs and no information concerning pre-pubertal dogs. The aim of this study was to describe regional differences in testicular artery blood flow in clinically normal post-pubertal and pre-pubertal dogs with no history of reproductive tract disease. Results The post-pubertal dogs produced normal ejaculates throughout the study. In all dogs the three different regions of the artery were imaged and monophasic flow with an obvious systolic peak and flow throughout diastole was observed on every occasion. The highest peak systolic velocity (PSV) and end diastolic velocity (EDV) were measured within the distal supra-testicular artery and marginal artery whilst the lowest PSV and EDV were measured within the intra-testicular arteries. Flow measurements were not different between left and right testes and were consistent between dogs on different examination days. Calculated resistance index (RI) and pulsatility index (PI) were lowest in the intra-testicular arteries. The pre-pubertal dogs had significantly smaller testes than the post-pubertal dogs (p < 0.05) and were unable to ejaculate during the study. The three different artery regions were imaged at every examination time point, and flow profiles had a similar appearance to those of the post-pubertal dogs. PSV, EDV, RI and PI showed a similar trend to the post-pubertal dogs in that values were lowest in the intra-testicular arteries. Notably, values of PSV, EDV, RI and PI were significantly lower (p < 0.05) in pre-pubertal dogs compared with post-pubertal dogs. Conclusions This study demonstrated important regional and pubertal differences in testicular artery blood flow of dogs, and form the basis for establishing baseline reference values that may be employed for the purposes of clinical diagnosis

    Origin and main ramifications of coeliac artery in Cerdocyon thous

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    Background: Cerdocyon thous is the canid with the greatest geographical coverage in South America. The aim of this study was to describe the origin, skeletopy, length and main branches of the coeliac artery in C. thous. Materials and methods: The dissections were performed on 14 cadavers of adult specimens, 6 males and 8 females, with a rostrosacral length average of 67.00 ± 4.7 cm and 62.09 ± 5.7 cm, respectively. The specimens were collected dead on highways on the banks of the Atlantic Forest (Rio de Janeiro) and the Pampa biome (Rio Grande do Sul) in Brazil. The cadavers were fixed and preserved in a formaldehyde solution until dissection. The coeliac artery was dissected, the length was measured “in situ” and its main branches were recorded. The coeliac artery emerged as a single artery in all dissected animals. Results: The average length of the coeliac artery was 1.43 ± 0.17 cm in males and 1.39 mm ± 0.24 cm in females, with no significant difference in this measurement between sexes. The predominant skeletopy was at the level of the second lumbar vertebra (57.1%), positioned on average 1.43 cm cranially to the cranial mesenteric artery. In most individuals (92.9%), the classic trifurcation was formed: the coeliac artery branched into the hepatic, left gastric, and lienal arteries. Only 1 male animal presented a bifurcation formed between the hepatic artery and a gastrolienal trunk. Conclusions: These anatomical characteristics are similar to those of other species of the Canidae family, possibly due to their phylogenetic proximity

    Socio-economic inequalities and COVID-19 incidence and mortality in Brazilian children: a nationwide register-based study

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    OBJECTIVES: This study aimed to estimate the incidence and mortality rates of coronavirus disease 2019 (COVID-19) in Brazilian children and to analyze its relationship with socio-economic inequalities in a state-level analysis. STUDY DESIGN: This is a nationwide register-based study. METHODS: To estimate the incidence and mortality rates of COVID-19 in Brazilian children aged 0-19 years, we extracted data of confirmed cases and deaths from the de-identified microdata catalog and official bulletins of the 27 Brazilian states' health department websites until September 3, 2020. Social and economic inequalities were evaluated using the Social Vulnerability Index and Gini coefficient, respectively. The relationship between COVID-19 rates in Brazilian children and socio-economic vulnerability at the state level was analyzed using Spearman's rank correlation. RESULTS: Of the 3,998,055 individuals with COVID-19 included in our database, 335,279 (8.4%) were children aged 0-19 years. Eight hundred deaths in children were registered, which accounts for about 0.7% of the deaths related to COVID-19 in the country. There were important differences in the incidence and mortality rates among Brazilian regions, and a correlation between mortality rates and social (ρ = 0.519; P-value = 0.007; effect magnitude: moderate) and economic (ρ = 0.615; P-value &lt; 0.001; effect magnitude: strong) inequalities was found in a state-level analysis. CONCLUSIONS: This population-based study showed important regional differences in COVID-19 estimates for children in Brazil and a relationship between mortality rates and socio-economic inequalities. The knowledge of sociogeographic differences in the estimates of COVID-19 is crucial to planning societal strategies and local decision-making to mitigate the effects of disease in the pediatric population

    Port choice in Rio de Janeiro, Brazil: an analysis of the perspectives of exporters and importers in the container market

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    This paper analysed the port choice process from the perspective of two types of agents: 1) exporters/forwarders; 2) importers/forwarders. We used stated preference data collected in the state of Rio de Janeiro, Brazil. Discrete choice models were tested. The best-performing models were mixed logit regression for both groups. The export model showed that road transport tariff, risk of cargo theft, number of ship calls, port tariff and cargo release time are important factors. The import models showed that taxation, road transport tariff, ship calls, port tariff and cargo release time are important variables. The models indicate that the ports in the region analysed are highly dependent on exogenous variables that port authorities cannot control. Some findings are achieved by comparing the outcomes for both groups. The value of time (VOT) referring to the willingness of companies to pay for the reduction of one unit (day) to release cargo at ports was calculated for each group. VOT for importers has a greater value. Different policy scenarios have been simulated to examine the impact of each policy on the market

    In Vitro Activity Of Artemisia Annua L (asteraceae) Extracts Against Rhipicephalus (boophilus) Microplus [atividade In Vitro De Extratos De Artemisia Annua L (asteraceae) Sobre Rhipicephalus (boophilus) Microplus]

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    The activity of plant extracts on parasites may indicate groups of substances that are potentially useful for controlling Rhipicephalus (Boophilus) microplus. The aim of the present study was to investigate the in vitro action of Artemisia annua extracts on this tick. The concentrations of the sesquiterpene lactones artemisinin and deoxyartemisinin present in plant extracts were quantified via high-performance liquid chromatography. Four extracts produced from the concentrated crude extract (CCE) were evaluated on larvae using the impregnated paper method, with readings after 24 hours of incubation. The engorged females were immersed in the CCE and in its four derived extracts for five minutes, with incubation for subsequent analysis of biological parameters. The extracts were not effective on the larvae at the concentrations tested (3.1 to 50 mg.mL-1). The CCE showed greater efficacy on engorged females (EC50 of 130.6 mg.mL-1 and EC90 of 302.9 mg.mL-1) than did the derived extracts. These results tend to confirm that the action of artemisinin on engorged females of R. (B.) microplus is conditional to their blood intake. In this case, in vitro methods would be inadequate for effective evaluation of the action of A. annua on R. (B.) microplus.2013135Amaral, N.K., Guidelines for the evaluation of ixodicides against the cattle tick Boophilus microplus (Canestrini, 1887) (Acari: Ixodidae) (1993) Revista Brasileira De Parasitologia Veterinária, 2 (2), pp. 144-151(2009) Anuário Da Pecuária Brasileira, p. 360. , ANUALPEC, Sao Paulo: Angra FNP PesquisasBorges, L.M.F., Acao do extrato hexanico de frutos maduros de Melia azedarach (Meliaceae) sobre Boophilus microplus (Acari: Ixodidae) em bezerros infestados artificialmente (2005) Revista De Patologia Tropical, 34 (1), pp. 53-59Cala, A.C., (2010) Avaliação Da Atividade De Artemisia Annua L., Melia Azedarach L. E Trichilia Claussenii C. Sobre Nematódeos Gastrintestinais De Ovinos, p. 64. , Dissertacao (Mestrado)- Universidade Estadual Paulista, Faculdade de Ciencias Agrarias e Veterinarias, JaboticabalCeleghini, R.M.S., Desenvolvimento e validacao de metodologia analitica por CLAE-IR para determinacao de artemisinina em Artemisia annua L (2009) Química Nova, 32 (4), pp. 875-878Chagas, A.C.S., Efeito acaricida de oleos essenciais e concentrados emulsionaveis de Eucalyptus em Boophilus microplus (2002) Brazilian Journal of Veterinary Research and Animal Science, 39 (5), pp. 247-253Chagas, A.C.S., Sensibilidade do carrapato Boophilus microplus a solventes (2003) Ciência Rural, 33 (1), pp. 109-114Creek, D.J., Kinetics of ironmediated artemisinin degradation:Effect of solvent composition and iron salt (2005) Journal of Pharmaceutical Sciences, 94 (8), pp. 1820-1829Drummond, R.O., Boophilus annulatus and B. Microplus: Laboratory tests of insecticides (1973) Journal of Economic Entomology, 66 (1), pp. 130-133Ekanem, A.P., Brisibe, E.A., Effects of ethanol extract of Artemisia annua L. Against monogenean parasites of Heterobranchus longifilis (2010) Parasitology Research, 106 (5), pp. 1135-1139Fernandes, F.F., Freitas, E.P.S., Acaricidal activity of an oleoresinous extract from Copaifera reticulata (Leguminosae: Caesalpinioideae against larvae of the southern cattle tick, Riphicephalus (Boophilus) microplus (Acari:Ixodidae) (2007) Veterinary Parasitology, 147 (1-2), pp. 150-154Ferreira, J.F.S., Agrotechnological aspects of the anti-malarial plant Artemisia annua and its potential use in animal health in Appalachia (2006) International Symposium on Perfume, Aromatic and Medicinal Plants, (2-4), pp. 797-804. , Revue de Regions Arides - Numero special - Actes du seminaire international les Plants a Parfum, Aromatiques et Medicinales (English version: International Center for Agricultural Research in Dry AreasFerreira, J.F.S., Nutrient Deficiency in the Production of Artemisinin, Dihydroartemisinic Acid, and Artemisinic Acid in Artemisia annua L (2007) Journal of Agricultural and Food Chemistry, 55 (5), pp. 1686-1694Ferreira, J.F.S., Gonzalez, J.M., Chemical and biological stability of artemisinin in bovine rumen fluid and its kinetics in goats (Capra hircus) (2008) Revista Brasileira De Parasitologia Veterinária, 17 (SUPPL. 1), pp. 103-109Furlong, J., O carrapato dos bovinos e a resistencia: Temos o que comemorar? (2007) A Hora Veterinária, 159, pp. 26-32Grisi, L., Impacto economico das principais ectoparasitoses em bovinos no Brasil (2002) A Hora Veterinária, 21 (125), pp. 8-10Heimerdinger, A., Extrato alcoolico de Capim-cidreira (Cymbopogon citratus) no controle do Boophilus microplus em bovinos (2006) Revista Brasileira De Parasitologia Veterinária, 15 (1), pp. 37-39Idris, U.A., Adam, S.E., Tartour, G., The anthelmintic efficacy of Artemisia herba-alba against Haemonchus contortus infection in goats (1982) Animal Health Quarterly, 22 (3), pp. 138-143Iqbal, Z., Anthelmintic activity of Artemisia brevifolia in sheep (2004) Journal of Ethnopharmacology, 93 (2), pp. 265-268Keiser, J., Artesunate and artemether are effective fasciolicides in the rat model and in vitro (2006) Journal of Antimicrobial Chemotherapy, 57 (6), pp. 1139-1145Keiser, J., Efficacy and safety of artemether against a natural Fasciola hepatica infection in sheep (2008) Parasitology Research, 103 (3), pp. 517-522Keiser, J., Utzinger, J., Food-borne trematodiasis: Current chemotherapy and advances with artemisinins and synthetic trioxolanes (2007) Trends In Parasitology, 23 (11), pp. 555-562Klayman, D.L., Qinghaosu (Artemisinin): Na antimalarial drug from China (1985) Science, 228 (4703), pp. 1049-1055La-Scalea, M.A., Silva, H.S.R.C., Ferreira, E., Reducao voltametrica de artemisinina e sua interacao com grupo heme (hemina) (2007) Brazilian Journal of Pharmaceutical Sciences, 43 (3), pp. 371-383Martins, R.M., Estudio in vitro de la accion acaricida del aceite esencial de la graminea Citronela de Java (Cymbopogon winterianus Jowitt) en la garrapata Boophilus microplus (2006) Revista Brasileira De Plantas Medicinais De Botucatu, 8 (2), pp. 71-78Meshnick, S.R., Second-generation antimamalarial endoperoxides (1996) Parasitology Today, 12 (2), pp. 79-82Ribeiro, V.L.S., Acaricidal properties of extracts from the aerial parts of Hypericum polyanthemum on the cattle tick Boophilus microplus (2007) Veterinary Parasitology, 147 (1-2), pp. 199-203Rodrigues, R.A.F., Otimizacao do processo de extracao e isolamento do antimalarico artemisinina a partir de Artemisia annua L (2006) Química Nova, 29 (2), pp. 368-372Silva, H.S.R.C., (2006) Antimaláricos Potenciais: Pró-fármacos Poliméricos E Formas De Liberação Controlada De Artemisinina, p. 209. , Tese (Doutorado)-Universidade de Sao Paulo, Sao PauloSimoes, C.M., (2004) Farmacognosia: Da Planta Ao Medicamento, p. 1102. , 5. ed. Porto Alegre: Editora da UFRGSFlorianopolis: Editora da UFSCTaranto, A.G., Estudo sobre o mecanismo de acao da artemisinina e dos endoperoxidos, a mais nova classe de agents antimalaricos (2006) Sitientibus, 34, pp. 47-58Tariq, K.A., Anthelmintic activity of extracts of Artemisia absinthium against ovine nematodes (2009) Veterinary Parasitology, 160 (1-2), pp. 83-8

    Bone Characteristics Of Broiler Chickens Fed Diets Supplemented With Solanum Glaucophyllum

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    The aim of this study was to assess the characteristics of the tibiotarsus of male broilers at 21 and 35 days of age. The percentages of collagenous proteins (CP), non-collagenous proteins (NCP), ash, and minerals (calcium, phosphorus, potassium and sodium), as well as weight of dried and defatted tibiotarsus in natura were determined. A total of 648 Cobb® male broilers were used in a random block design study with 6 treatments, 6 replicates, and 18 birds per experimental unit. The treatments consisted of diet supplementation with 0.0, 0.5, 1.0, 1.5, 2.0, and 2.5 μg of active Vitamin D3 per kg of feed. The birds were weighed at 21 and 35 days of age and one bird per repetition with the mean weight of the experimental unit was slaughtered to collect the tibiotarsus. The organic and mineral composition of the bone was affected by the addition of active Vitamin D3 to the feed. Our results indicate that a dose of up to 1.50 μg of 1,25(OH)2D3/kg of feed is ideal for male broilers between 8 and 35 days of age.37138139

    Search for electroweak production of single top quarks in ppˉp\bar{p} collisions.

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    We present a search for electroweak production of single top quarks in the electron+jets and muon+jets decay channels. The measurements use ~90 pb^-1 of data from Run 1 of the Fermilab Tevatron collider, collected at 1.8 TeV with the DZero detector between 1992 and 1995. We use events that include a tagging muon, implying the presence of a b jet, to set an upper limit at the 95% confidence level on the cross section for the s-channel process ppbar->tb+X of 39 pb. The upper limit for the t-channel process ppbar->tqb+X is 58 pb. (arXiv
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