Analyses of baseline survey data on rinderpest in bahr el ghazal province,with proposal of an improved vaccination strategy against rinderpest for southern Sudan

Summary Results from analyses of baseline surveilance data on rinderpest are used for proposing an improved vaccination strategy against rinderpest in southern Sudan. Sera from 4,074 (47%) of the total sample of 8,565 cattle collected in a series of cross-sectional surveys in 400 cattle camps in the Bahr el Ghazal Province of southern Sudan were tested for rinderpest antibodies using the standard virus neutralisation test (VNT) technique: 77·4% were positive while 22·6% gave negative results. The data were cross-classified according to five variables: herd management, breed, age, sex and geographic region (grazing location). The percentage antibody-positivity level (taken as an approximation of past experience with rinderpest antigen and the corresponding prevalence ratio estimates of relative risk) for each variable are discussed within the context of the known characteristics of immunity to rinderpest in endemic areas and the husbandry practices of the cattle owners in the study area. Results suggest that rinderpest “hot-spots” of transmission and/or low level of herd immunity should be mapped out for concentrated efforts to vaccinate calves and young adults so that the high level of antibody-positivity observed in this study can be maintained and transmission permanently interrupted.

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Resumen Se utilizaron los resultados del análisis de la información base de un reconocimiento epidemiológico de rinderpest, para proponer una estratégia de vacunación contra la enfermedad en el Sur de Sudán. Se analizaron 4074 (47%) sueros bovinos de una muestra de 8565 colectados en una serie de reconocimientos seccionales cruzados, realizados en 400 colonias ganaderas en la Provincia de Bahr el Ghazal situada en el Sur de Sudán; la prueba de laboratorio utilizada para detectar anticuerpos fue la de neutralización viral (PNV). De éstos, 77·4% fueron positivos mientras que 22·6% dieron resultados negativos. Los datos se clasificaron en forma cruzada, teniendo en cuenta cinco variables: Manejo del hato, raza, edad, sexo y región geográfica (lugar de pastoreo). Se discute el porcentaje del nivel de anticuerpos positivos (tomado como una aproximación de la experiencia pasada con el antígeno de rinderpest y el estimado del nivel de prevalencia correspondiente del riesgo relativo) para cada variable, dentro del contexto de las características conocidas de la inmunidad contra rinderpest en áreas endémicas y las prácticas de manejo de los propietarios del ganado en el área de estudio. Los resultados sugieren, que los lugares peligrosos que contienen rinderpest virulentos y/o lugares en donde existe el riesgo de transmisión de la enfermedad debido al bajo nivel de anticuerpos deben delimitarse, para así concentrar los esfuerzos hacia la vacunación de terneros y adultos jóvenes, de manera tal, que los altos niveles de anticuerpos observados en este estudio puedan mantenerse y la transmisión pueda interrumpirse permanentemente.

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Résumé Les resultats de l'analyse des données d'une enquête sur la peste bovine ont permis de proposer une stratégie de lutte contre cette maladie au Sud-Soudan. Les anticorps bovipestiques ont été recherchés par la technique standard du test de neutralisation du virus (VNT) sur des sérums provenant de 4074 prélèvements (47 p. 100) effectués sur 8565 têtes de bétail issues de plusieurs enquêtes avec recoupements dans 400 campements pastoraux de la province de Bahr el Ghazal au Sud-Soudan. 74 p. 100 des résultats ont été positifs; 22, 6p. 100 ont été négatifs. Les données ont fait l'objet d'un classement croisé en fonction de cinq variables: mode de gestion du troupeau, race, age, sexe et région géographique (parcours pastoraux). Le niveau, en pourcentage, des anticorps positifs retenu comme moyen d'approximation entre l'expérience antérieure avec l'antigène bovipestique et l'estimation du taux d'incidence correspondant au risque relatif pour chaque variable, fait l'objet d'une discussion dans le contexte des caractéristiques communes de l'immunité contre la peste bovine pour les zones d'endémicité et les modes de gestion des troupeaux dans la zone étudiée. Les résultats suggèrent que les “points chauds” de tranmission et/ou les faibles taux d'immunité des troupeaux pourraient faire l'objet d'une carte comparative afin de concentrer les efforts de vaccination des veaux et des jeunes adultes pour maintenir le seuil élevé de positivité antigénique observé et interrompre la transmission permanente de la maladie.

     

Blood flow to the distal part of the teat (mammary papilla) of lactating dairy cows

Relative blood flow to tissues of the distal part of the teat (mammary papilla) in 5 lactating dairy cows was determined, using 15-microns nonradioactive carbonized microspheres. Highest relative blood flow occurred in the epithelial region (zone A) of the teat canal (papillary duct) which comprised both teat canal epithelium and papillated portion of the stratum papillare. Blood flow to these tissues was more than 4 times greater than blood flow to equivalent tissues of the mucosal rosette. The high rate of metabolic activity indicated by this relatively high blood flow may be required to support secretion of antimicrobial substances and continual synthesis of epithelial cells to replace those lost during milking.     

Risk Factors for Dairy Cow Mastitis in the Central Highlands of Ethiopia

This study, with the objective of assessing the effect of risk factors on dairy cow mastitis in the central highlands of Ethiopia, was undertaken between February and September 2001 in the urban and peri-urban areas of Addis Ababa, Ethiopia. A prevalence study and questionnaire survey were carried out simultaneously. Clinical examination of lactating udders and California mastitis test (CMT) determined clinical and subclinical mastitis, respectively. Risk factors for subclinical and clinical mastitis were identified from data on animals and farm management by chi-square analysis and subsequent logistic regression. Cows aged at least 8 years, with poor body condition, with at least 8 parities and in at least the eighth month of lactation had a significantly higher risk for subclinical mastitis (p < 0.05). The risk was reduced for cows up to their third parity in good body condition and for cows receiving dry cow therapy. Cows aged at least 4 years, or with at least 8 parities, cows in at least the fourth month of lactation, cows with poor body condition, leaking milk or previous udder infections had a significantly higher risk of clinical mastitis (p <0.05). The risk was reduced by the use of separate towels for udder cleaning and by drying off at the end of lactation. Most of the risk factors were in agreement with previous reports. However, stage of lactation and drying-off style were in contrast to others. Further research is needed to identify the interrelationship between production level, specific pathogens and management risk factors.     

Past and predicted future effects of housing growth on open space conservation opportunity areas and habitat connectivity around National Wildlife Refuges

Context

Housing growth can alter suitability of matrix habitats around protected areas, strongly affecting movements of organisms and, consequently, threatening connectivity of protected area networks.

Objectives

Our goal was to quantify distribution and growth of housing around the U.S. Fish and Wildlife Service National Wildlife Refuge System. This is important information for conservation planning, particularly given promotion of habitat connectivity as a climate change adaptation measure.

Methods

We quantified housing growth from 1940 to 2000 and projected future growth to 2030 within three distances from refuges, identifying very low housing density open space, “opportunity areas” (contiguous areas with <6.17 houses/km²), both nationally and by USFWS administrative region. Additionally, we quantified number and area of habitat corridors within these opportunity areas in 2000.

Results

Our results indicated that the number and area of open space opportunity areas generally decreased with increasing distance from refuges and with the passage of time. Furthermore, total area in habitat corridors was much lower than in opportunity areas. In addition, the number of corridors sometimes exceeded number of opportunity areas as a result of habitat fragmentation, indicating corridors are likely vulnerable to land use change. Finally, regional differences were strong and indicated some refuges may have experienced so much housing growth already that they are effectively too isolated to adapt to climate change, while others may require extensive habitat restoration work.

Conclusions

Wildlife refuges are increasingly isolated by residential housing development, potentially constraining the movement of wildlife and, therefore, their ability to adapt to a changing climate.

     

Quantification of Wheat spindle streak mosaic virus and Soil borne cereal mosaic virus in resistance testing of field samples of triticale using real-time RT-PCR

Journal of Plant Diseases and Protection - Triticale, a cross between rye and wheat, is a crop important for animal feed and the production of biogas and ethanol. Soil-borne viruses found in wheat...     

DanTox—a novel joint research project using zebrafish (Danio rerio) to identify specific toxicity and molecular modes of action of sediment-bound pollutants

Introduction

The European Water Framework Directive aims to achieve a good ecological and chemical status in surface water of European rivers by the year 2015. Since sediments and particulate matter act as secondary sources for pollutants, applied sediment toxicology is perceived to play a major role for obtaining new knowledge that can contribute to successful attainment of the goal. However, the existing bioassays for sediment toxicity analyses do not provide sufficient data concerning bioavailability of environmental pollutants. In this regard, there is an urgent need to combine sediment contact assays with gene expression analysis to investigate mechanism-specific sediment toxicity.

Purpose

The aim of the novel joint research project is to develop a eukaryotic test system, which can be used to investigate the ecotoxicological effects of contaminated sediments on gene expression level (DNA-array and RT-PCR). Current ecotoxicological research customarily involves a battery of bioassays to cover different toxicological endpoints (e.g., teratogenicity, genotoxicity, mutagenicity, Ah-receptor-mediated toxicity, neurotoxicity). In contrast, methods that detect alterations in gene expression offer deeper insight by elucidating how chemical exposure and/or environmental challenge affect multiple metabolic pathways leading to these particular kinds of toxic response. Gene expression profiles reflect the way cells and organisms adapt or respond to a changing environment.

Conclusion

The present project aspires to increase the fundamental molecular and physiological knowledge concerning the mode of action of environmental toxicants in zebrafish (Danio rerio). By working with partners from the academic and research institutions as well as from industry and waterway regulations, the success of this basic research-driven joint project in terms of development and implementation of novel sediment toxicity methods will be realized.     

Comparison of California Mastitis Test (CMT), Somatic Cell Counts (SCC) and bacteriological examinations for detection of camel (Camelus dromedarius) mastitis in Ethiopia

A total of 956 quarter milk samples from 253 traditionally managed lactating camels were collected aseptically from Negele (Borena Region), Dire Dawa, and Gewane (Afar Region), Ethiopia, according to multi-stage sampling. The quarter milk samples were subjected to California Mastitis Test (CMT), Somatic Cell Counts (SCC) and bacteriological examinations. Five hundred and seventy one (59.7%) quarter milk samples had microorganisms. Of these, 428 (75.0%) had isolates that were identified as major pathogens (MAP) and 143 (25.0%) as minor pathogens (MIP). A positive correlation was found between CMT scores and bacteriological classes (MAP, MIP) (p-value = 0.00). Strong correlation (p-value = 0.00) between CMT scores and SCC was recorded. The differences among the median log SCC of bacteriological classes (MAP, MIP) were not significant (p-value = 0.24). Similarly, the application of the cut-off level of 2.5 x 10(5) ml(-1) indicated less agreement (p-value = 0.32) for bacteriological classes MAP and MIP.     

Occurrence of hydatidosis in slaughter buffaloes (Bos bubalis) and helminths in stray dogs in Kathmandu Valley, Nepal

The study aimed at identifying the occurrence of hydatidosis in slaughter buffaloes and helminth eggs, particularly Taenia spp. eggs in stray dogs' fecal samples in Kathmandu Valley, Nepal. The study period was from November, 2004 to April, 2005. A total of 500 buffalo carcasses in a slaughterhouse, at the riversides and individual butchers'sites were examined for the presence of hydatid cysts. The cyst fluid was collected and microscopically examined to determine if it was fertile or not. Of the 500 carcasses examined, 10.6% had hydatid cysts. Specifically, the slaughterhouse carcasses had a 6.7% occurrence of hydatid cysts, whereas those examined at riversides and individual butcher places had 10.0% and 12.7%, respectively. Distributions of the hydatid cysts by specific organs showed single occurrence of 6.4% in lungs, 2.4% in livers and 1.8% in both, livers and lungs. In a total of 53 infected buffaloes, 58.5% were fertile and 41.5% sterile cysts. Overall, 366 faecal samples from stray dogs were collected around buffaloes slaughtering areas (slaughterhouse and individual butcher places), riversides, garbage sites and temple sites. These samples were examined by formalin-ether concentration technique to investigate the presence of different helminth eggs. The total prevalence of Taenia, hookworms, Trichuris/Capillaria,Toxocara, Spirometra and Physaloptera eggs were 12.8%, 18.3%, 19.1%, 12.8%, 1.4% and 1.9%, respectively.     

Analysis of bioavailable arsenic in rice with whole cell living bioreporter bacteria

A multiwell plate bioassay was developed using genetically modified bacteria (bioreporter cells) to detect inorganic arsenic extracted from rice. The bacterial cells expressed luciferase upon exposure to arsenite, the activity of which was detected by measurement of cellular bioluminescence. The bioreporter cells detected arsenic in all rice varieties tested, with averages of 0.02-0.15 microg of arsenite equivalent per gram of dry weight and a method detection limit of 6 ng of arsenite per gram of dry rice. This amounted to between approximately 20 and 90% of the total As content reported by chemical methods for the same sample and suggested that a major proportion of arsenic in rice is in the inorganic form. Calibrations of the bioassay with pure inorganic and organic arsenic forms showed that the bacterial cells react to arsenite with highest affinity, followed by arsenate (with 25% response relative to an equivalent arsenite concentration) and trimethylarsine oxide (at 10% relative response). A method for biocompatible arsenic extraction was elaborated, which most optimally consisted of (i) grinding rice to powder, (ii) mixing with an aqueous solution containing pancreatic enzymes, (iii) mechanical shearing, (iv) extraction in mild acid conditions and moderate heat, and (v) centrifugation and pH neutralization. Detection of mainly inorganic arsenic by the bacterial cells may have important advantages for toxicity assessment of rice consumption and would form a good complement to total chemical arsenic determination.