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排序方式: 共有437条查询结果,搜索用时 625 毫秒
61.
Mesquita João Rodrigo Istrate Claudia Santos-Ferreira Nânci L. Ferreira Ana S. Abreu-Silva Joana Veiga José van der Poel Wim H. M. Nascimento Maria S. J. 《Tropical animal health and production》2019,51(2):481-485
Tropical Animal Health and Production - As in most of the African continent, the status of hepatitis E virus (HEV) infection in domestic animals in São Tomé and Príncipe, an... 相似文献
62.
Predicting land cover changes and their impact on the sediment influx in the Lake Balaton catchment 总被引:2,自引:0,他引:2
The land cover pattern in the Lake Balaton catchment (Hungary) has been changing since decollectivization in the 1990s. These
land cover changes significantly impact the landscape connectivity, controlling the influx of sediments into the lake. A comparison
of high resolution land cover maps from 1981, 2000 and 2005 showed a significant extensification of the agriculture with land
cover conversions from arable land and vineyards to grassland and forest. For each land unit transition probabilities were
assessed using logistic regression techniques to evaluate to which extent land cover changes are controlled by physical or
socio-economic parameters. A stochastic land cover allocation algorithm was applied to generate future land cover patterns.
The landscape connectivity for each of the simulated land cover patterns was assessed by means of a distributed routing algorithm.
The simulations suggest that further land abandonment in the upslope parts of the catchment will cause a non-linear reduction
of average soil erosion rates. The changes, however, have a relatively low impact on the sediment volume entering the lake
because of the land unit’s poor connectivity with permanent river channels. The major contributors to the lakes sediment load
are the vineyards near the lakeshore. They are likely to be maintained because of their touristic value. A significant reduction
of the total sediment input in the lake can be expected only if soil conservation measures in the vineyards near the shorelines
are undertaken. 相似文献
63.
Casteleyn C Van den Broeck W Simoens P 《Veterinary immunology and immunopathology》2007,120(3-4):124-135
Tonsils form a first line of defence against foreign antigens and therefore play a key role in immunity. Since documented information about ovine tonsils is limited, a study was performed in which the morphological characteristics and the volume of lymphoid tissue present in each ovine tonsil were determined. The tonsils of five adult healthy sheep were examined histologically and the volumes were estimated using the Cavalieri method. The pharyngeal tonsil had a mean volume of 1296.1 ± 205.9 mm3 and was by far the largest ovine tonsil, followed by the paired palatine tonsil with a mean volume of 715.0 ± 110.5 mm3. The tonsil of the soft palate, the paired tubal and paraepiglottic tonsils and the lingual tonsil were much smaller with a mean volume of, respectively, 90.3 ± 24.9 mm3, 80.1 ± 24.3 mm3, 29.7 ± 11.8 mm3 and 10.1 ± 2.8 mm3. The folds and crypts of the pharyngeal and palatine tonsils were covered by a reticular and a non-reticular epithelium. Both tonsils were mainly composed of primary and secondary lymph follicles. The palatine tonsils contained 1–3 crypts with a few secondary infoldings. Lymphoid tissue in the tonsil of the soft palate was located at the nasopharyngeal (dorsal) side of the soft palate. The tubal tonsil was lined with a pseudostratified columnar ciliated epithelium and consisted of scattered lymphoid cells and lymph follicles. The paraepiglottic tonsil consisted of lymph follicles and aggregated lymphoid cells. Its overlying keratinized stratified squamous epithelium was folded and often heavily infiltrated by lymphocytes. The ovine lingual tonsil was not macroscopically visible and did not contain clearly distinguishable lymph follicles. It consisted of aggregations of lymphoid cells that were mainly located within the vallate lingual papillae. 相似文献
64.
Sander J. Zwart Wim G.M. Bastiaanssen Charlotte de Fraiture 《Agricultural Water Management》2010,97(10):1617-1627
The growing pressure on fresh water resources demands that agriculture becomes more productive with its current water use. Increasing water productivity is an often cited solution, though the current levels of water productivity are not systematically mapped. A global map of water productivity helps to identify where water resources are productively used, and identifies places where improvements are possible. The WATPRO water productivity model for wheat, using remote sensing data products as input, was applied at a global scale with global data sets of the NDVI and surface albedo to benchmark water productivity of wheat for the beginning of this millennium. Time profiles of the NDVI were used to determine the time frame from crop establishment to harvest on a pixel basis, which was considered the modelling period. It was found that water productivity varies from approximately 0.2 to 1.8 kg of harvestable wheat per cubic metre of water consumed. From the 10 largest producers of wheat, France and Germany score the highest country average water productivity of 1.42 and 1.35 kg m−3, respectively. The results were compared with modelling information by Liu et al. (2007) who applied the GEPIC model at a global scale to map water productivity, and by Chapagain and Hoekstra (2004) who used FAO statistics to determine water productivity per country. A comparison with Liu et al. showed a good correlation for most countries, but the correlation with the results by Chapagain and Hoekstra was less obvious. The global patterns of the water productivity map were compared with global data sets of precipitation and reference evapotranspiration to determine the impact of climate and of water availability reflected by precipitation. It appears that the highest levels of water productivity are to be expected in temperate climates with high precipitation. Due to its non-linear relationship with precipitation, it is expected that large gains in water productivity can be made with in situ rain water harvesting or supplemental irrigation in dry areas with low seasonal precipitation. A full understanding of the spatial patterns by country or river basin will support decisions on where to invest and what measures to take to make agriculture more water productive. 相似文献
65.
Atle Foss Hans van de Vis Wout Abbink Bert Lambooij Bjørn Roth 《Journal Of Applied Aquaculture》2019,31(1):34-47
In the present study, selected temperature drops were examined to investigate the effects of live chilling on stress and welfare in turbot and sole. This study demonstrated that rapid temperature drops from 11°C–12°C and 18°C–18.7°C to 4°C–0°C in turbot resulted in higher blood sodium and potassium at 0°C (164 mmol l?1, 4.4 mmol ?1) compared to 4°C (153 mmol l?1, 3.1 mmol ?1), indicating osmoregulatory disturbance. A rapid temperature drop from 18°C to 0°C in Senegal sole also resulted in higher blood sodium and potassium at 0°C (164 mmol l?1, 4.8 mmol ?1) compared to the control group at 18°C (157 mmol l?1, 3.2 mmol ?1). Based on present findings, we conclude that immersion in ice water will have a negative effect on the animal osmoregulatory capacity, and we recommend that turbot and sole are stunned before slaughter. 相似文献
66.
On‐farm evaluation of inundative biological control of Ostrinia nubilalis (Lepidoptera: Crambidae) by Trichogramma brassicae (Hymenoptera: Trichogrammatidae) in three European maize‐producing regions
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Marion Giraud Wim van Dijk Špela Modic Maurizio Sattin Gregor Urek 《Pest management science》2016,72(2):246-254
67.
Jerry van Dijk Wim A.M. Didden Frans Kuenen Herman A. Verhoef 《Soil biology & biochemistry》2009,41(8):1717-6164
Reducing decomposition and mineralization of organic matter by increasing groundwater levels is a common approach to reduce plant nutrient availability in many peat meadow restoration projects. The soil community is the main driver of these processes, but how community composition is affected by peat meadow restoration is largely unknown. Furthermore, it is unclear whether restoration induced changes could lead to altered decomposition and mineralization rates. We determined soil community composition in restored peat meadows with different groundwater levels and soil pH. This composition was subsequently used in food web model calculations of C and N mineralization rates to assess whether differences in soil community composition may have contributed to differences in decomposition and mineralization rates observed between these meadows.Community composition of micro-organisms, Collembola and Enchytraeidae differed considerably between meadows and were correlated with differences in groundwater levels and soil pH. Collembolan and enchytraeid species from wet and neutral environments were more abundant at meadows with higher groundwater levels. Lower fungal to bacterial PLFA ratios and higher numbers of protozoa indicated an increased importance of the bacterial part of the food web at meadows with higher groundwater levels. Food web model calculations suggested that the observed changes in community composition would lead to higher rates of C and N mineralization at meadows with high groundwater levels. Results from modeling were consistent with field measurements of C mineralization, but not with measurements of N mineralization.We conclude that understanding changes in soil community composition in response to specific restoration measures may help us to better understand ecosystem responses to wetland restoration schemes, especially regarding soil biogeochemical processes. 相似文献
68.
Ragnvi Hagman Bert Jan Reezigt Hanna Bergstr?m Ledin Erika Karlstam 《Acta veterinaria Scandinavica》2009,51(1):2
Background
Canine pyometra is a life-threatening disease common in countries where spaying of dogs is not routinely performed. The disease is associated with endotoxemia, sepsis, systemic inflammatory response syndrome (SIRS) and a 3–4% mortality rate. Blood lactate analysis is clinically valuable in predicting prognosis and survival, evaluating tissue perfusion and treatment response in human and veterinary critical care settings. The aims of the present study were to investigate 1) the blood lactate levels of female dogs with pyometra by a hand-held analyser and 2) if these levels are related with the clinical status or other biochemical or hematological disorders.Methods
In total 31 female dogs with pyometra admitted for surgical ovariohysterectomy and 16 healthy female control dogs were included in the present study. A complete physical examination including SIRS-status determination was performed. Blood samples for lactate concentrations, hematological and biochemical parameters, acid-base and blood gas analysis and other laboratory parameters were collected and subsequently analysed. The diagnosis pyometra was verified with histopathological examination of the uterus and ovaries. Increased hospitalisation length and presence of SIRS were used as indicators of outcome.Results
In the pyometra group the median blood lactate level was 1,6 mmol l-1 (range <0.8–2.7 mmol l-1). In the control group the median lactate level was 1,2 mmol l-1 (range <0.8–2.1 mmol l-1). Of the 31 bitches 19 (61%) fulfilled 2 or more criteria for SIRS at inclusion, 10 bitches (32%) fulfilled 3 of the SIRS criteria whereas none accomplished more than 3 criteria. Lactate levels did not differ significantly between the pyometra and control group, or between the SIRS positive and SIRS negative dogs with pyometra. Increased lactate concentration (>2.5 mmol l-1) was demonstrated in one female dog with pyometra (3%), and was not associated with longer hospitalisation or presence of SIRS. Lactate measurement was not indicative of peritonitis. None of the bitches died during or within two months of the hospital stay. The measurements of temperature, heart rate, respiratory rate, percentage bandforms of neutrophilic granulocytes, α2-globulins, creatinin, pvCO2, TCO2 and base excess showed significant differences between the SIRS positive and the SIRS negative pyometra cases.Conclusion
Increased blood lactate concentrations were demonstrated in 3% (1/31), and SIRS was present in 61% (19/31) of the female dogs with pyometra. Preoperative lactate levels were not related with presence of SIRS or prolonged hospitalisation. Lactate measurement was not indicative of peritonitis. The value of a single and repeated lactate analysis in more severely affected cases remains to be determined. 相似文献69.
Rat bite fever (RBF) is a bacterial zoonosis for which two causal bacterial species have been identified: Streptobacillis moniliformis and Spirillum minus. Haverhill fever (HF) is a form of S. moniliformis infection believed to develop after ingestion of contaminated food or water. 相似文献
70.