2,993 research outputs found
Identification and characterization of Rhipicephalus (Boophilus) microplus candidate protective antigens for the control of cattle tick infestations
The cattle ticks, Rhipicephalus (Boophilus) spp., affect cattle production in tropical and subtropical regions of the world. Tick vaccines constitute a cost-effective and environmentally friendly alternative to tick control. The recombinant Rhipicephalus microplus Bm86 antigen has been shown to protect cattle against tick infestations. However, variable efficacy of Bm86-based vaccines against geographic tick strains has encouraged the research for additional tick-protective antigens. Herein, we describe the analysis of R. microplus glutathione-S transferase, ubiquitin (UBQ), selenoprotein W, elongation factor-1 alpha, and subolesin (SUB) complementary DNAs (cDNAs) by RNA interference (RNAi) in R. microplus and Rhipicephalus annulatus. Candidate protective antigens were selected for vaccination experiments based on the effect of gene knockdown on tick mortality, feeding, and fertility. Two cDNA clones encoding for UBQ and SUB were used for cattle vaccination and infestation with R. microplus and R. annulatus. Control groups were immunized with recombinant Bm86 or adjuvant/saline. The highest vaccine efficacy for the control of tick infestations was obtained for Bm86. Although with low immunogenic response, the results with the SUB vaccine encourage further investigations on the use of recombinant subolesin alone or in combination with other antigens for the control of cattle tick infestations. The UBQ peptide showed low immunogenicity, and the results of the vaccination trial were inconclusive to assess the protective efficacy of this antigen. These experiments showed that RNAi could be used for the selection of candidate tick-protective antigens. However, vaccination trials are necessary to evaluate the effect of recombinant antigens in the control of tick infestations, a process that requires efficient recombinant protein production and formulation systems
Studies on neonatal calf diarrhoea
The work described in this Thesis is concerned with the effects of diarrhoea on newborn calves of known serum immune globulin concentrations and the influence that such colostrum-derived passive immunity may have on the outcome of the condition. The work is divided into three parts as follows:- Part 1 General Introduction and Review of the Literature In this part a general review and criticism of the relevant literature concerned with the probable aetiology, pathogenesis, prophylaxis and treatment of neonatal calf diarrhoea is reported. Part 2 Studies on the Influence of some environmental, therapeutic and managemental factors on the severity of diarrhoea, and upon the survival of newborn calves of known serum immaune globulin concentration A farm survey performed during the period from February to June 1968, investigating the serum immune globulin concentration; of dairy heifer calves using the Zinc Sulphate Turbidity Test is reported. 327 dairy heifer calves of two to seven days of age retained in 47 closed dairy herds in the West of Scotland were sampled. Some aspects of the management prevailing on the farms were investigated and the possible effects of such management on the serum immune globulin concentrations attained by the newborn calves were looked into. The relationship between the serum immune globulin concentration and the incidence on these farms of death from E.coli septicaemia and diarrhoea is also discussed. The serum immune globulin concentrations were found to be influenced by the place of birth. Those calves born indoors, showed significantly lower values than those born out of doors. Furthermore, a significant difference was found amongst the calves born indoors, in that calves born in the byre showed significantly lower values than those born in boxes. The time of first feeding colostrum and whether the calves were left with or removed from their dams at the time of birth, also influenced the serum immune globulin concentrations. Calves born in the byre and fed colostrum within six hours of birth had significantly higher serum immune globulin concentrations than those fed after six hours, and calves born in boxes and left with their dams for more than 12 hours had significantly higher serum immune globulin concentrations than those removed from their dams at birth or when found. The overall mortality rate for calves up to 1 month of age recorded in this survey was 11 per cent. The highest mortality rate was observed in the byre-born calves (calves with the lowest serum immune globulin concentrations) and the lowest mortality was seen in those calves born in the field (calves with the highest serum immune globulin concentrations). It was demonstrated that by adopting a method of management whereby ingestion of colostrum by the calf occurred within six hours of birth while remaining with its mother for at least 12 hours, the serum immune globulin concentrations were increased significantly. As a result a marked decline in the mortality rate, and incidence of diarrhoea was achieved. Experimental evidence was produced indicating that in hypogammaglobulinaemic calves, the parenteral administration of chloramphenicol, and the oral administration of Furazolidone used as treatment and as prophylactic measures, had little beneficial effect on the outcome of calf diarrhoea. Using hypogammaglobulinaemic calves, with similar serum immune globulin concentrations no difference was found in mortality rate between diarrhoeic calves treated intravenously with fluid and electrolytes (Darrow's solution) and untreated diarrhoeic calves. Experimental evidence was produced suggesting that the protective properties of a high serum immune globulin concentration was more effective against calf diarrhoea than any of the above mentioned therapies. The oral use of anticholinergic substances would appear to be contraindicated in the diarrhoeic syndrome observed in the present study. (Abstract shortened by ProQuest.)
Genetic relationships within and among Iberian fescues (Festuca L.) based on PCR-amplified markers
The genus Festuca comprises approximately 450 species and is widely distributed around the world. The Iberian Penninsula, with more than 100 taxa colonizing very diverse habitats, is one of its main centers of diversification. This study was conducted to assess molecular genetic variation and genetic relatedness among 91 populations of 31 taxa of Iberian fescues, based on several molecular markers (random amplified polymorphic DNA, amplified fragment length polymorphisms, and trnL sequences). The analyses showed the paraphyletic origin of the broad-leaved (subgenus Festuca, sections Scariosae and Subbulbosae, and subgenus Schedonorus) and the fine-leaved fescues (subgenus Festuca, sections Aulaxyper, Eskia, and Festuca). Schedonorus showed a weak relationship with Lolium rigidum and appeared to be the most recent of the broad-leaved clade. Section Eskia was the most ancient and Festuca the most recent of the fine-leaved clade. Festuca and Aulaxyper were the most related sections, in concordance with their taxonomic affinities. All taxa grouped into their sections, except F. ampla and F. capillifolia (section Festuca), which appeared to be more closely related to Aulaxyper and to a new independent section, respectively. Most populations clustered at the species level, but some subspecies and varieties mixed their populations. This study demonstrated the value in combining different molecular markers to uncover hidden genetic relationships between populations of Festuca
Fenomenologia: uma visão para a pesquisa em enfermagem
La disciplina de enfermería necesita identificarse con una filosofía que le permita otorgar un sentido interpretativo a los fenómenos sociales o individuales; y la investigación cualitativa ofrece la metodología necesaria para llevar a cabo la interpretación de los significados bajo un análisis crítico y reflexivo. El objetivo del presente trabajo fue reflexionar sobre diferentes tradiciones filosóficas en torno a la fenomenología, al explorar los pensamientos de Edmund Husserl, Martin Heidegger y Alfred Schütz. Se realizó un ensayo teórico cuyo insumo literario se obtuvo de repositorios y fuentes de datos electrónicas, se incluyeron artículos publicados de los años 2010 al 2014, se utilizaron combinaciones de ocho palabras clave y se excluyeron aquellos artículos que no mencionaron el enfoque teórico de los filósofos de interés. Se concluye que las tres perspectivas filosóficas plantean una estrategia metodológica factible de ser utilizada dentro de la investigación cualitativa en enfermería, ya sea bajo la escuela descriptiva de Husserl, la postura interpretativa de Heidegger o la visión social de Schütz.The discipline of nursing needs to identify with a philosophy that allows give an interpretive sense of social or individual phenomena; and qualitative research provides the necessary methodology to perform the interpretation of the meanings under a critical and reflective analysis. The aim of this study was to reflect on different philosophical traditions around phenomenology, exploring the thoughts of Edmund Husserl, Martin Heidegger and Alfred Schütz. A theoretical essay whose literary input was obtained from repositories and electronic data sources was conducted, published in the years 2010 to 2014 were included combinations of eight key words were used and those items not mentioned the theoretical approach of philosophers were excluded of interest. It is concluded that the three philosophical perspectives pose a feasible methodological strategy to be used in qualitative research in nursing, either under the descriptive school of Husserl, Heidegger interpretive stance or the social vision of Schütz.A disciplina de enfermagem precisa identificar-se com uma filosofia que permite dar um sentido interpretativo dos fenômenos sociais ou individuais; e pesquisa qualitativa fornece a metodologia necessária para realizar a interpretação dos significados sob uma análise crítica e reflexiva. O objetivo deste estudo foi refletir sobre diferentes tradições filosóficas em torno de fenomenologia, explorando os pensamentos de Edmund Husserl, Heidegger e Alfred Martin Schütz. Um ensaio teórico cuja entrada literária foi obtida a partir de repositórios e fontes de dados eletrônicos foram realizadas, publicado nos anos de 2010 a 2014 foram incluídos foram utilizadas combinações de oito palavras-chave e esses itens não mencionou a abordagem teórica de filósofos foram excluídos juros. Conclui-se que as três perspectivas filosóficas representam uma estratégia metodológica viável para ser utilizado na pesquisa qualitativa em enfermagem, seja sob a escola descritiva de Husserl, Heidegger postura interpretativa ou a visão social de Schütz
Proporción sexual y Morfometría para dos poblaciones de Ceroglossus chilensis (eschscholtz, 1829) (Coleoptera: Carabidae) en la Región del Biobio Chile ( text spanish)
La cooperación transfronteriza entre regiones europeas : en busca de un instrumento jurídico eficaz
Dissolving star cluster candidates
We present a list of 34 neglected entries from star cluster catalogues
located at relatively high galactic latitudes ( 15) which
appear to be candidate late stages of star cluster dynamical evolution.
Although underpopulated with respect to usual open clusters, they still present
a high number density contrast as compared to the galactic field. This was
verified by means of (i) predicted model counts from different galactic
subsystems in the same direction, and (ii) Guide Star Catalog equal solid angle
counts for the object and surrounding fields. This suggests that the objects
are physical systems, possibly star clusters in the process of disruption or
their fossil remains. The sample will be useful for followup studies in view of
verifying their physi cal nature.Comment: manuscript in LATEX with 7 pages, 7 figures .ps Accepted for
Astronomy and Astrophysics main journa
Second-harmonic generation in vortex-induced waveguides
We study the second-harmonic generation and localization of light in a
reconfigurable waveguide induced by an optical vortex soliton in a defocusing
Kerr medium. We show that the vortex-induced waveguide greatly improves
conversion efficiency from the fundamental to the second harmonic field.Comment: 3 pages, 4 figures, submitted to Optics Letter
Ciudades socialmente sostenibles
Los Objetivos de Desarrollo Sostenible (ODS) marcan la referencia a seguir en todo lo relativo a la Agenda Mundial hasta el año 2030, de la totalidad de los ODS, es necesario centrarnos en el ODS número 11: Lograr que las ciudades y los asentamientos urbanos sean inclusivos, seguros, relativos y sostenibles. Con estas coordenadas, realizaremos un análisis de la situación actual y del papel que tiene y sobre todo que podría tener la profesión de Trabajo Social en el diseño de Ciudades Socialmente Sostenibles; sin duda, nos encontramos ante una oportunidad de conseguir la mejora de la accesibilidad social de la ciudadanía. El tema ambiental analizado en un contexto de desarrollo sostenible introduce cambios significativos en la configuración social y académica al enfoque interdisciplinario y al proceso crítico necesarios, con la posibilidad de una relación/conexión interminable entre investigación y práctica. Un nuevo paradigma ecológico en el Trabajo Social, enfatiza que los problemas ambientales son el resultado de las mismas presiones que crean la injusticia social y abre nuevas perspectivas y oportunidades para actuar de acuerdo con los principios del desarrollo sostenible. Tener en cuenta los problemas ambientales en las estrategias y la acción del Trabajo Social pide a los/as profesionales que usen sus habilidades para hablar en nombre de la vulnerabilidad social. Nos enfrentamos con un reto, posibilitar la transmisión de una conciencia social y ecológica entre generaciones, así como el sentido de responsabilidad de la comunidad para el mantenimiento de ese sistema.info:eu-repo/semantics/acceptedVersio
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