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181.
Infection with Brucella canis has been diagnosed in Sweden for the first time. It was diagnosed in a three-year-old breeding bitch with reproductive disturbances. Fifteen in-contact dogs were tested repeatedly and all of them were negative for B. canis. The source of infection could not be defined. The present article describes the case and the measures undertaken and gives a short review over B. canis. Recommendations on how to avoid the infection in non-endemic countries are given.  相似文献   
182.
Cyclopia (honeybush) species are widely-used in the production of a South African herbal tea and are endemic to the fynbos region of the Western and Eastern Cape Provinces. Honeybush is still one of the orphan agriculture crops and recent breeding efforts by researchers are hampered by the lack of basic genetic information e.g. basic chromosome numbers and ploidy levels. This study determined nuclear DNA content and ploidy level of various genotypes of three Cyclopia species using flow cytometry and cytological counting of chromosomes. Nuclei analysis of young leaves of C. genistoides, C. longifolia and C. subternata were done using a flow cytometer, while root tip squashes were carried out in order to correlate flow cytometry results. Flow cytometry analysis indicated differences in the nuclear DNA content among and within species whilst the DNA ploidy level only differed among species. Cyclopia genistoides had a higher DNA ploidy level (≥?10C) and DNA content (10.63 pg) than C. longifolia (6.09 pg) and C. subternata (5.99 pg), with no differences observed between the ploidy level of the latter two species (6C). The inferred ploidy level from nuclear DNA content by flow cytometry was consistent in all 30 genotypes of C. longifolia, and 24 of the 25 C. subternata and in only four of the 15 C. genistoides studied genotypes. These findings are important in breeding new cultivars with desired horticultural traits, thus improving the commercial characteristics for the sustainable production of honeybush.  相似文献   
183.
Knots in trees: strain distribution in a naturally optimised structure   总被引:1,自引:0,他引:1  
Electronic speckle pattern interferometry was applied to directly measure the distribution of longitudinal, tangential, and shear strains in small boards of Norway spruce (Picea abies (L.) Karst.) exposed to tensile load in longitudinal direction. A sample with a central intergrown knot and one with an equivalent loose knot were compared with reference samples made of clear wood with an artificial central circular or square hole, respectively. The observed measurements were compared with a finite element (FE) simulation. The FE model was based on a geometric model to quantify the local fibre orientation and a micromechanical model to estimate elastic constants of clear wood and knot tissue. Both the measurements and simulation clearly illustrate a rather homogenous strain distribution around the intergrown knot. In comparison, the natural optimisation of dispersing strain peaks is less efficient in the case of loose knots. The artificial circular and square holes in samples with parallel fibre orientation lead to high gradients in the strain field and peak values in vicinity of the disturbance.  相似文献   
184.
185.

Background

Anaplasma phagocytophilum is the causative agent of tick-borne fever in ruminants and human granulocytotropic anaplasmosis (HGA). The bacterium is able to survive for several months in immune-competent sheep by modifying important cellular and humoral defence mechanisms. Little is known about how different strains of A. phagocytophilum propagate in their natural hosts during persistent infection.

Methods

Two groups of five lambs were infected with each of two 16S rRNA gene variants of A. phagocytophilum, i.e. 16S variant 1 which is identical to GenBank no M73220 and 16S variant 2 which is identical to GenBank no AF336220, respectively. The lambs were infected intravenously and followed by blood sampling for six months. A. phagocytophilum infection in the peripheral blood was detected by absolute quantitative real-time PCR.

Results

Both 16S rRNA gene variants of A. phagocytophilum established persistent infection for at least six months and showed cyclic bacteraemias, but variant 1 introduced more frequent periods of bacteraemia and higher number of organisms than 16S rRNA gene variant 2 in the peripheral blood.

Conclusion

Organisms were available from blood more or less constantly during the persistent infection and there were individual differences in cyclic activity of A. phagocytophilum in the infected animals. Two 16S rRNA gene variants of A. phagocytophilum show differences in cyclic activity during persistent infection in lambs.  相似文献   
186.
Existing knowledge about the development of the porcine immune system was extended by phenotypic characterization of leukocyte subsets and with assessment of Mannan-Binding Lectin (MBL) and immunoglobulin concentrations in peripheral blood of healthy piglets. Single-color and/or double-color flow cytometry using monoclonal antibodies against CD1, CD3, CD4, CD8a CD14, CD21, CD172 (SWC3a), CD284 (TLR4), SLA I, and SLA II were performed to identify T-lymphocyte subsets, B-lymphocytes, monocytes, and granulocytes. ELISA was used to measure the concentration of serum proteins. Several of the analyzed parameters seem to be affected at the time of weaning which took place at 4–5 weeks of age. Using principal component analysis, all analyzed variables – except one – were grouped into 8 factors with distinct developmental profiles. Several of these factors revealed an apparent suppression, a steady state or an acceleration of the developmental age profiles around weaning.In conclusion, results indicate that weaning suppresses a broad spectrum of adaptive immune variables and that this was evident immediately after weaning as well as after a lag period of about one week. On the contrary, variables of the innate immune system seem to be stimulated immediately after weaning. At the time considered to have the highest infection pressure T-cells and TLR4+ cells were markedly enhanced, whereas the expression of SLA I did not seem to be affected by weaning.  相似文献   
187.
Endotoxemia causes significant mortality and morbidity in horses. The mechanisms underlying this complex pathophysiology remain unclear. Therefore, effective tools to treat endotoxemia in horses are lacking. Furthermore, the multifactorial and multiorgan pathophysiology of equine endotoxemia has not been fully addressed, especially the lung injury associated with endotoxemia. Within the context of the broader picture of endotoxemia and lung injury, we offer a perspective on the roles of pulmonary intravascular macrophages in endotoxin-induced lung inflammation in horses.  相似文献   
188.
People from all ethnic backgrounds spend some of their leisure time in green areas. This study found that urban parks are more inclusive green places than non-urban green areas, and that urban parks can promote social cohesion. The objective of the research was to establish the extent to which urban parks facilitate social cohesion and how social interaction and place attachment can contribute to such cohesion. Quantitative research (a survey) and qualitative research (observations and interviews) carried out in five urban parks in the Netherlands revealed that there are many similarities in the ways that ethnic groups use urban parks and in the meanings of such parks to these groups. Urban parks are sites where different ethnic groups mingle and where informal and cursory interactions can stimulate social cohesion. Furthermore, being involved and concerned with parks can facilitate attachment to these places. Urban parks can provide a vital locality where everyday experiences are shared and negotiated with a variety of people. The design of a park, its location and people's image of the park in combination with the cultural characteristics of various ethnic groups inform the opportunities for intercultural interactions.  相似文献   
189.
ObjectiveTo determine the induction doses, then minimum infusion rates of alfaxalone for total intravenous anaesthesia (TIVA), and subsequent, cardiopulmonary effects, recovery characteristics and alfaxalone plasma concentrations in cats undergoing ovariohysterectomy after premedication with butorphanol-acepromazine or butorphanol-medetomidine.Study designProspective randomized blinded clinical study.AnimalsTwenty-eight healthy cats.MethodsCats undergoing ovariohysterectomy were assigned into two groups: together with butorphanol [0.2 mg kg?1 intramuscularly (IM)], group AA (n = 14) received acepromazine (0.1 mg kg?1 IM) and group MA (n = 14) medetomidine (20 μg kg?1 IM). Anaesthesia was induced with alfaxalone to effect [0.2 mg kg?1 intravenously (IV) every 20 seconds], initially maintained with 8 mg kg?1 hour?1 alfaxalone IV and infusion adjusted (±0.5 mg kg?1 hour?1) every five minutes according to alterations in heart rate (HR), respiratory rate (fR), Doppler blood pressure (DBP) and presence of palpebral reflex. Additional alfaxalone boli were administered IV if cats moved/swallowed (0.5 mg kg?1) or if fR >40 breaths minute?1 (0.25 mg kg?1). Venous blood samples were obtained to determine plasma alfaxalone concentrations. Meloxicam (0.2 mg kg?1 IV) was administered postoperatively. Data were analysed using linear mixed models, Chi-squared, Fishers exact and t-tests.ResultsAlfaxalone anaesthesia induction dose (mean ± SD), was lower in group MA (1.87 ± 0.5; group AA: 2.57 ± 0.41 mg kg?1). No cats became apnoeic. Intraoperative bolus requirements and TIVA rates (group AA: 11.62 ± 1.37, group MA: 10.76 ± 0.96 mg kg?1 hour?1) did not differ significantly between groups. Plasma concentrations ranged between 0.69 and 10.76 μg mL?1. In group MA, fR, end-tidal carbon dioxide, temperature and DBP were significantly higher and HR lower.Conclusion and clinical relevanceAlfaxalone TIVA in cats after medetomidine or acepromazine sedation provided suitable anaesthesia with no need for ventilatory support. After these premedications, the authors recommend initial alfaxalone TIVA rates of 10 mg kg?1 hour?1.  相似文献   
190.
Management practices designed to increase carbon sequestration via perennial tree crops are potential tools to mitigate the consequences of climate change. Changes in orchard management could enable growers to meet eco-verification market demands for products with a low carbon footprint and potentially exploit the emerging business opportunity in carbon storage, while enhancing the delivery of ecosystem services that depend on soil carbon stocks. However, there is no standard methodology to verify any potential claims of carbon storage by perennial vine crops. We developed a robust methodology to quantify carbon storage in kiwifruit orchards. Soil carbon stocks (SCS) were determined in six depth increments to 1 m deep in two adjacent kiwifruit blocks, which had been established 10 (“young”) and 25 (“old”) years earlier. We used a space-for-time analysis. Our key results were the young and old kiwifruit block stored about 139 and 145 t C/ha to 1 m depth. Between 80–90 percent of the SCS were stored in the top 0.5 m, and 89–95 percent in the top 0.7 m; there was no significant difference between the SCS in row and alley to a depth of 0.5 m; a CV of 5–15 percent indicates that 4–10 cores are needed for 80 percent confidence in the estimated SCS; we recommend separating each core into the depths 0–0.1, 0.1–0.3, 0.3–0.5, and 0.5–1 m to allow the assessment of SCS dynamics; we detected a weak spatial pattern of the SCS only for the old kiwifruit block with a range of about 3 m. A sampling bay along a vine row should have a maximum length of 3 m. We then assessed SCS in more than sixty kiwifruit orchards throughout New Zealand. They stored on average 174.9 ± 3 t C ha?1 to 1 m depth. On average, 51 percent of the SCS down to 1 m depth were stored in the top 0.3 m, which is the standard depth according to the Kyoto protocol. About 72 percent of the SCS to 1 m depth were captured when increasing the sampling depth to 0.5 m. These results underscore the necessity to analyze SCS in an orchard to at least 0.5 m deep. Using the same methodology to 1 m deep, we determined SCS in two wine grape vineyards on shallow, stony alluvial soils. We found a difference between vineyard and adjacent pasture SCS of nearly 16 t/ha. As the vines are 25 years old, this equates to carbon sequestration rates of 640 kg ha?1 yr?1. Our results of the space-for-time analysis also showed that all sequestration had occurred below 0.5 m. Therefore, we decided to sample C to a greater depth. In a 30-year old kiwifruit orchard and an adjacent pasture, SCS was measured to 9 m deep. In the kiwifruit orchard, we found a sequestration rate of 6.3 tons of C per hectare per year greater than in the adjacent pasture that was the antecedent land use.  相似文献   
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