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261.
No registered fungicide controls Mucor piriformis, a cause of severe postharvest storage rot in pears, but the experimental fungicide RH 886 (active ingredients: 77% 5-chloro-2-methylisothiazol-3-(2H)-one and 23% 2-methylisothiazol-3-(2H)-one) has an ED50 of 23.1 μg ml?1 in 5 min exposure for germination of sporangiospores of M. piriformis and an ED50 of 9.9 μg ml?1 for mycelial growth. Mixing RH 886 into infested, amended soil at 8 mg g?1 soil or mixing copper sulfate into soil at 1 mg g?1 soil prevented sporulation of M. piriformis. Application of RH 886 to pear fruits prior to inoculation, or immersion of fruits in solutions of RH 886 containing sporangiospores of M. piriformis significantly reduced fruit infection.  相似文献   
262.
OBJECTIVES: Low-field magnetic resonance imaging machines are being used more often in veterinary practice for the investigation of sinonasal disease. The aim of this retrospective study was to describe and characterise the low-field magnetic resonance imaging features of nasal tumours in dogs. METHODS: The Queen's Veterinary School Hospital magnetic resonance imaging database (2001-2005) was searched for dogs with a magnetic resonance imaging diagnosis of a nasal tumour. Fifty cases with histological diagnosis of nasal tumour were found. The appearance and extent of the nasal tumour as well as the involvement of adjacent anatomic structures were examined against a checklist. RESULTS: The most common magnetic resonance imaging findings were as follows. (1) Soft tissue mass replacing the destroyed nasal conchae and/or ethmoturbinates (98 per cent of cases). (2) Nasal septum destruction (68 per cent of cases). (3) Retained secretions with or without mass caudally in frontal sinuses (62 per cent of cases). (4) Nasal/frontal bone destruction (52 per cent of cases). Low-field magnetic resonance imaging allowed differentiation of tumour tissue from retained secretions or necrotic tissue. Magnetic resonance imaging was invaluable in assessing the extension of the tumour into the maxillary recesses, caudal recesses, nasopharynx, adjacent bones and cranial cavity. The tumour often extended caudally into the frontal sinuses, nasopharynx and perhaps most importantly into the caudal recesses. Tumour extension into the cranial cavity was not common (16 per cent), and only three of these cases showed neurological signs. However, 54 per cent of cases showed focal meningeal (dural) hyperintensity, although the significance of this is unclear. A significant difference (P<0.05) in tumour signal intensity between the sarcomas and carcinomas was found. CLINICAL SIGNIFICANCE: The use of a low-field magnetic resonance imaging technique is excellent for the diagnosis and determination of extent of sinonasal tumours.  相似文献   
263.
Abstract

CASE HISTORY: A Jersey herd of 350 cows and 70 heifers located in the Taranaki region of New Zealand ceased milking in June 2011. Ten cows died during the subsequent 14 days. For at least 9 months, the cows had received palm kernel expeller (PKE) and molasses supplements. Additional Cu supplementation was provided through the water system. Total Cu intake was calculated to be 400?mg/day/cow.

CLINICAL AND PATHOLOGICAL FINDINGS: Half of the cows died suddenly while others presented with anorexia, depression and ataxia, which progressed to recumbency and death after 1 to 3 days. Clinical signs were mild dehydration, cyanosis and firm faeces which were covered in dark blood. Mean concentrations of Cu in liver and kidney in three of the dead cows were 3,900 and 440?µmol/kg fresh weight (FW), respectively. Haemorrhages were observed throughout the alimentary tracts and in muscles, and there were ecchymotic haemorrhages on the epi- and endocardia. The livers were swollen and the gall bladder walls were inflamed.

DIAGNOSIS: High concentrations of Cu in the liver and kidney are characteristic findings of chronic Cu toxicity.

TREATMENT: The remaining herd was fed 200?mg Mo, as sodium molybdate, per cow per day and all Cu supplements were removed including those provided by the water supply. This reduced mean concentrations of Cu in liver from 3,100 to 1,320?µmol/kg FW within 26 days in the five live animals that were biopsied. There were no further deaths.

CLINICAL RELEVANCE: In dairy herds where excessive Cu intakes have resulted in high liver Cu concentrations and caused chronic Cu toxicity, the removal of all Cu supplements and provision of high intakes of Mo (200?mg/cow/day) can markedly reduce liver Cu stores within 4 weeks.  相似文献   
264.
Abstract

AIM: To describe the seasonal pattern of development of third-stage infective larvae (L3) from eggs of Teladorsagia (=Ostertagia) circumcincta, Trichostrongylus colubriformis and Haemonchus contortus on pasture in the North Island of New Zealand.

METHODS: Sheep faeces containing known numbers of eggs of all three nematode species were deposited on, or buried in, pasture plots at three sites, viz coastal Manawatu, Upper Hutt Valley, and East Cape hill country. Development was measured by recovering L3 from faeces, herbage and soil 28–31 days after deposition on 13–18 occasions, between January 2005 and July 2006. Analysis of the number of larvae recovered used a mixed model including number of eggs deposited, weight of faeces recovered (an assumed indicator of earthworm activity), site, contamination date, and position of deposited faeces, i.e. on the surface or buried.

RESULTS: There was a significant effect of contamination date on development of all three species, with maximum numbers ofL3 developing between late spring (November) and early autumn (March), and minimum numbers in June and July. There were large differences between species, with H. contortus exhibiting a long period (April to October) where development was close to zero, whereas T. circumcincta developed to some extent all year round. Development of T. colubriformis was intermediate between the other two species.

Burying faeces containing nematode eggs increased the number of L3 recovered compared with surface deposition (p≤0.001), although there were a small number of exceptions involving only T. colubriformis. The weight of faeces recovered at harvest, which was assumed to be an indication of earthworm activity, was correlated with the number of L3 recovered for all species (p<0.001). In a separate analysis, earthworms were assumed tohave been active if <5 g faeces remained at harvest. Where this occurred, the number of L3 of T. colubriformis and T.circumcincta recovered was reduced by 56% and 58%, respectively (p<0.001).

CONCLUSIONS: A marked seasonal pattern of development was observed for all three species, with the most larvae developing in spring-early autumn and the least in winter. This seasonal pattern was most pronounced in H. contortus and least obvious in T. circumcincta. Burying faeces containing eggs generally resulted in more L3 being recovered, whilst the apparent activity of earthworms resulted in fewer larvae being recovered.  相似文献   
265.
Breed incidence of lymphoma in a UK population of insured dogs   总被引:3,自引:2,他引:1  
Canine lymphoma is one of the commonest forms of spontaneous canine neoplasia. Improved understanding of the genetic and environmental risk factors for canine lymphoma, including breed differences, may have comparative benefits for the study of non‐Hodgkin's lymphoma in humans. In this study, data from a pet insurance company were used to estimate the incidences of canine lymphoma for pedigree breeds in the UK. Out of a total of 130 684 insured dogs, 103 had a diagnosis of lymphoma recorded. A significant breed effect was found with the boxer, bulldog and bull mastiff breeds, all having a high incidence of lymphoma. The small number of lymphoma cases recorded may have limited our ability to detect other breeds with an elevated risk. Incidence of lymphoma was found to increase with age, peaking at 10 years of age.  相似文献   
266.
267.
268.
The objective was to investigate the effects of reproductive seasonality on gamete quality in plains bison (Bison bison bison). Epididymal sperm (n = 61 per season), collected during the breeding season (July–September), had significantly higher post‐thaw total motility (36.76 ± 14.18 vs 31.24 ± 12.74%), and lower linearity (0.36 ± 0.06 vs 0.39 ± 0.04) and wobbliness (0.49 ± 0.04 vs 0.51 ± 0.03; mean ± SD) compared to non‐breeding season (January–March) samples. Representative samples (n = 4) from each season were used in heterologous IVF trials using cattle oocytes. Cleavage, morulae and blastocyst percentage were higher for breeding vs non‐breeding season sperm samples (81.88 ± 6.8 vs 49.94 ± 6.77; 41.89 ± 13.40 vs 27.08 ± 23.21; and 30.49 ± 17.87 vs 13.72 ± 18.98%, respectively). Plains bison ovaries collected during the breeding (n = 97 pairs) and non‐breeding (n = 100 pairs) seasons were classified as luteal or follicular. Oocytes recovered from these ovaries were classified into five grades based on morphology. There was no significant difference in the number of luteal ovaries or grades of oocytes recovered. Oocytes were matured, fertilized (with frozen sperm from three bison bulls) and cultured in vitro. Cleavage percentage was higher for oocytes collected during breeding vs non‐breeding season (83.72 ± 6.42 vs 73.98 ± 6.43), with no significant difference in subsequent development to blastocysts. In summary, epididymal sperm from non‐breeding season had decreased total motility and resulted in reduced embryo production in vitro. Oocytes collected during non‐breeding season had reduced ability to be matured, fertilized and/or undergo cleavage in vitro. Data suggested that season influenced gamete quality in plains bison.  相似文献   
269.
The relationship between milk yield and cystic ovarian disease in cattle   总被引:1,自引:0,他引:1  
Studies were conducted to understand the relationship, if any, between the amount and pattern of milk yield and the occurrence of cystic ovarian disease (COD) in dairy cattle. More than 70 cows with cysts were compared with herd mates of similar lactation number. Total milk yield in lactations when cysts occurred and in the preceding lactations were not different from the corresponding lactations in control cows. Patterns of monthly milk yield did not differ between the two groups of cows. However, weekly analysis in early lactation revealed differences. Both groups of cows achieved peak yields at a similar time (5.4 +/- 1.2 vs 5.7 +/- 1.9 weeks post partum in normal vs cows with COD). However, owing to an early decline in yield of cows with COD, their duration of peak yield was significantly shorter (P less than 0.05) than in the control cows (3.2 +/- 2.2 vs 5.6 +/- 2.4 weeks). Both the attainment and the decline of peak yield occurred 5.6 (range = 2-15) weeks before the cysts were diagnosed. It is concluded that COD is not particularly a disease of higher yielding cows and that COD has no discernible effect on the milk yield or its pattern. It is speculated, however, that some cows in early lactation, while trying to meet the requirements of sustained peak milk production, are more susceptible to minor environmental changes (such as new social interactions, or changes in diet). These events may lead to a drop in milk production and disruption of events controlling normal ovulation, resulting in the formation of ovarian cysts.  相似文献   
270.
Radiocarbon (14C) content of surface waters inferred from a coral record from the Galapagos Islands increased abruptly during the upwelling season (July through September) after the El Nino event of 1976. Sea-surface temperatures (SSTs) associated with the upwelling season also shifted after 1976. The synchroneity of the shift in both 14C and SST implies that the vertical thermal structure of the eastern tropical Pacific changed in 1976. This change may be responsible for the increase in frequency and intensity of El Nino events since 1976.  相似文献   
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