排序方式： 共有19条查询结果，搜索用时 15 毫秒
1.
2.
Anthony F. Craig Livio Heath Jan E. Crafford Juergen A. Richt Robert Swanepoel 《The Onderstepoort journal of veterinary research》2021,88(1)
African swine fever virus (ASFV) causes a lethal and contagious disease of domestic pigs. In South Africa, the virus historically circulated in warthogs and ornithodorid ticks that were only found in warthog burrows in the north of the country. Regulations implemented in 1935 to prevent transfer of infected animals or products to the south initially proved effective but from 2016 there have been outbreaks of disease in the south that cannot be traced to transfer of infection from the north. From 1963 there were widespread translocations of warthogs to the south, initially from a source considered to be free of ornithodorid ticks. We undertook to determine whether sylvatic circulation of ASFV occurs in the south, including identification of potential new vectors, through testing extralimital warthogs for antibody and ticks for virus. Results of testing warthogs for antibody and other species of ticks for virus will be presented separately. Here we report finding Ornithodoros (Pavlovskyella) zumpti ticks in warthog burrows for the first time. This occurred in the Eastern Cape Province (ECP) in 2019. Since African swine fever was recognised in the ECP for the first time in 2020 and outbreaks of the disease in domestic pigs continue to occur there, priority should be given to determining the distribution range and vector potential of O. (P.) zumpti for ASFV. 相似文献
3.
4.
Letizia M. Davi Massimo Baldi Luciano Penazzi Michelina Liboni 《Pest management science》1992,35(1):63-67
The purpose of this work was to compare the method and analytical results obtained by liquid/liquid extraction with those of solid-phase extraction, in particular with the use of an Empore disc, in the investigation of pesticide residues in drinking water. 相似文献
5.
Different organisms respond to landscape configuration and spatial structure in different terms and across different spatial
scales. Here, regression models with variation partitioning were applied to determine relative influence of the three groups
of variables (climate, land use and environmental heterogeneity) and spatial structure variables on plant, bird, orthopteran
and butterfly species richness in a region of the Southern Alps, ranging in elevation from the sea level to 2,780 m. Grassland
and forest cover were positively correlated with species richness in both taxonomic groups, whilst species richness decreased
with increasing urban elements and arable land. The variation was mainly explained by the shared component between the three
groups in plants and between landscape and environmental heterogeneity in birds. The variation was related to independent
land use effect in insects. The distribution in species richness was spatially structured for plants, birds and orthopterans,
whilst in butterflies, no spatial structure was detected. Plant richness was associated with linear trend variation and broad-scale
spatial structure in the northern part of the region, whilst bird richness with broad-scale variation which occurs on the
external Alpine ridge. Orthopteran diversity was strongly related to fine-scale spatial structure, generated by dynamic processes
or by unmeasured spatially structured abiotic factors. Although the study was carried out in relatively small area, the four
taxonomic groups seem to respond to biodiversity drivers in a surprisingly different way. This has considerable implications
for conservation planning as it restricts the usefulness of simple indicators in prioritizing areas for conservation purposes. 相似文献
6.
N Govoni A Parmeggiani G Galeati P Penazzi R De Iasio U Pagotto R Pasquali C Tamanini E Seren 《Reproduction in domestic animals》2007,42(1):39-43
Ghrelin, the endogenous ligand of the growth hormone (GH) secretagogue receptor, is considered a pleiotropic regulator involved in a large array of functions, including control of energy balance, regulation of food intake and, more recently, modulation of the reproductive axis. The present study was aimed at determining the changes in plasma concentrations of acyl-ghrelin in pregnant and lactating sows, with special emphasis on the relationship with the levels of GH, leptin, non-esterified fatty acids (NEFA) and insulin-like growth factor (IGF-1). Blood samples were collected via jugular venipuncture from 22 multiparous sow 30, 60 and 90 days after artificial insemination, 7 and 21 days after farrowing and at first oestrus post-weaning. Plasma concentrations of acyl-ghrelin, leptin, GH and IGF-1 were quantified by validated radioimmunoassay; NEFA were determined using a colorimetric procedure. Plasma acyl ghrelin levels were highest at 30 days of pregnancy and decreased thereafter and during lactation. At the beginning of lactation, GH, IGF-1 and NEFA concentrations significantly increased, while a significant reduction occurred in leptin. In conclusion, ghrelin concentrations in sow maternal circulation does not seem to play an important role in maintaining circulating GH levels during lactation; moreover, ghrelin is not associated with leptin, NEFA and IGF-1 levels. 相似文献
7.
8.
Costa LM Rembeck K Ribeiro MF Beelitz P Pfister K Passos LM 《Veterinary journal (London, England : 1997)》2007,174(3):673-676
Ehrlichia canis has a worldwide geographic distribution, occurring particularly in tropical and subtropical areas. In Brazil, the main vector in urban areas is believed to be the brown dog tick Rhipicephalus sanguineus, but little is known about the occurrence, transmission and other epidemiological aspects of canine ehrlichiosis in rural areas, where Amblyomma ticks are found more frequently than R. sanguineus. A sero-prevalence study of canine ehrlichiosis was carried out in three distinct rural regions of the State of Minas Gerais, Brazil. Serum samples were collected from 226 dogs living on farms in Lavras (n=85), Belo Horizonte (n=45), and Nanuque (n=96) and were analyzed by an indirect fluorescent antibody test for the detection of anti-Ehrlichia canis antibodies. Age, breed, sex, presence of ticks and packed cell volume were also recorded. There were 65.6% positive dogs in Nanuque, 37.8% in Belo Horizonte, and 24.7% in Lavras. Animals living in Nanuque were 4.6 times more likely to be serologically positive than dogs living in the other two regions and antibody titres were considerable higher in this area. Male dogs, dogs >5 years of age, those infested with ticks, and mongrels all showed higher rates of positivity. The results point to the importance of canine ehrlichiosis in rural areas and indicate the need for further studies on natural transmission and maintenance of the disease. 相似文献
9.
Stefania Squadrone Maria Cesarina Abete Marco Rizzi Gabriella Monaco Livio Favaro 《Water, air, and soil pollution》2018,229(2):41
The concentrations of trace and non-trace elements were determined in blood and fibers of alpacas (Vicugna pacos) from a north Italian area, as well as in their pasture forages. This is the first investigation regarding this species in Italy, and the first considering alpaca’s fiber as bioindicator worldwide. Metal contents in blood were in the decreasing order: copper?>?zinc?>?aluminum?>?selenium?>?lead?>?nickel?>?manganese?>?chromium?>?arsenic and cadmium, while in fiber, metal levels were in the following order: aluminum?>?zinc?>?copper?>?manganese?>?chromium?>?nickel?>?selenium?>?lead?>?arsenic and cadmium. Antimony, beryllium, mercury, tin, and thallium were below the limit of quantification (0.010 mg kg?1). The analysis of the alpacas’ forage confirmed the same trend found in fiber, suggesting that metal bioaccumulation was affected by diet. These preliminary results have shown that all the trace elements studied bioaccumulated to a greater extent in the fibers of the alpaca than in the blood. Accordingly, we may suggest that alpaca fibers could be used for monitoring exposure especially to non-essential metals like aluminum, cadmium, and lead, and could constitute a suitable non-invasive method for measuring trace and non-trace element exposure in camelids. 相似文献
10.