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31.
SUMMARY Outbreaks of ovine weaner nutritional myopathy occurring in the southwest of Western Australia outside the recognised selenium-responsive areas have been investigated. One hundred and five sheep died in 3 outbreaks following 5 months grazing cereal stubble paddocks. Liver selenium and glutathione peroxidase activities, measured as an index of biological availability of dietary selenium, indicated that the selenium status of the animals was probably adequate. A comparison of liver selenium and α-tocopherol concentrations and glutathione peroxidase activity was made with both selenium supplemented sheep and sheep affected with selenium-responsive nutritional myopathy. In all cases investigated in this study liver α-tocopherol levels in affected animals were low and this may be important in the aetiology of this myopathy.  相似文献   
32.
This study was undertaken to address the increasing need for a strategic approach to industry–science data collections in the face of reducing resources and growing need for evidence in fisheries management. The aim was to evaluate progress in the development of plans and procedures that can be employed to collect, record and use fishing industry knowledge and data in the evidence base for managing fisheries. This was achieved by reviewing industry‐led data initiatives already undertaken or ongoing within the United Kingdom to document how these projects have/are incorporating fishing industry data into the process of management decision‐making; canvassing stakeholder opinion on data gaps and whether these could be filled by data gathered by commercial fishing vessels; establishing what issues might prevent or stimulate commercial fishing vessels in collecting data when they have the opportunity; and describing guidance on a step‐by‐step process for gathering scientific information such that fishers are empowered to collect the right data, at the right times and in the right format for their fishery. Given recent advances in the collection, interpretation and application of fisheries‐dependent data, we compare progress made in the UK to other areas of the world. We conclude that there is considerable evidence of a paradigm shift from the conventional practice of scientists asking fishers to provide data for scientific analyses towards full engagement of key stakeholders in data collection.  相似文献   
33.
Objective To summarize the medical knowledge surrounding aardvarks to date, to describe the ophthalmic examination of a specimen with a chronic history of an upper eyelid lesion, of an assumed blind left eye, and to detail the anesthesia procedure performed. Procedure A 23‐year‐old aardvark was examined under general anesthesia and multiple ocular abnormalities were detected in the left eye (globe deviation, corneal opacities, iridodonesis, and aphakia). A thickening of the palpebral conjunctiva affecting the medial upper eyelid with erosion of the normal eyelid margin anatomy was identified. The adnexal lesion was resected by a wedge resection and histopathology was performed. Suture breakdown 3 days postoperatively required a second surgery, where buried sutures were used. The surgical techniques and postoperative care are discussed. Results The histopathology revealed mucosal hyperplasia and moderate neutrophilic and lymphoplasmacytic blepharitis. No causal organisms were identified. Following initial wound dehiscence and a modified surgical technique, the upper eyelid healed without complication and retained complete function. Conclusions The eyelid lesion involved a benign inflammatory and hyperplastic pathology of unknown etiology. Adjusting routine ophthalmic surgical techniques to wildlife and zoo animals can be challenging and complicated. It is important to understand the nature of the animals being managed, their circadian cycle, and habitat, to adjust and individualize the surgical approach, instrumentation, suture material, and perioperative treatment.  相似文献   
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Two different UK limestone grasslands were exposed to simulated climate change with the use of nonintrusive techniques to manipulate local climate over 5 years. Resistance to climate change, defined as the ability of a community to maintain its composition and biomass in response to environmental stress, could be explained by reference to the functional composition and successional status of the grasslands. The more fertile, early-successional grassland was much more responsive to climate change. Resistance could not be explained by the particular climates experienced by the two grasslands. Productive, disturbed landscapes created by modern human activity may prove more vulnerable to climate change than older, traditional landscapes.  相似文献   
36.
对影响绵羊健康和生产性能的一些重要的矿物质营养方面进展和可能会对中国养羊生产产生的影响进行了介绍和讨论,其中着重讨论了以下几个方面的专题:硒和碘,蠕虫感染与矿物质营养,食土和铁的代谢,镉及其与硫和相互作。结果表明对放牧绵羊的矿物质营养进行优化决策,对于最大限度地提高草原养羊业的生产力是完全必要的。  相似文献   
37.
  • 1. Throughout Europe, populations of anadromous fish and lampreys have declined over the past centuries due to human activities. River lamprey Lampetra fluviatilis are representative of such species and are listed in international conservation agreements.
  • 2. Historic (1908–09 to 1913–14) and modern (1995–96 to 2003–04) data were available on commercial catches of river lampreys in the tidal Ouse, north‐east England. During 2003–04, additional traps were operated by the University of Durham, downstream of the commercial fishery.
  • 3. Catch per unit effort (CPUE) in the modern commercial fishery showed considerable variation between fishing seasons, ranging from a median CPUE of 0.5 lampreys per trap per day in 2000–01 to a median of 22.3 lampreys per trap per day in 2003–04.
  • 4. The estimated catch of adult river lampreys each season in the historic fishery ranged between 25 500 (1913–14) and 54 500 (1910–11). Recent catches tended to be smaller, with a minimum catch of 9083 lampreys (2000–01) and a maximum of 30 992 lampreys (2003–04).
  • 5. CPUE increased with discharge, up to a point above which CPUE declined with further increase in discharge. Migratory activity may be reduced at high flows and not stimulated at low flows, although the fishing efficiency of the traps themselves was probably reduced during high flows.
  • 6. Samples of river lampreys caught in the university's traps were marked and released. Based upon the number of recaptures, the absolute minimum relative exploitation level of the commercial traps, over the whole fishing season, was estimated as 9.9%. The effect of such a reduction in the spawning population upon future recruitment is at present unknown.
  • 7. The population of river lampreys in the tidal Ouse is potentially threatened by an unregulated increase in fishing effort. Current legislation needs to be modified to allow effective fishery management.
Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
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39.
White Muscle Disease of sheep occurs in Western Australia as distinct syndromes in lambs and weaner sheep. Mean liver selenium concentrations of lambs and weaners with WMD and unaffected by WMD were 0.19 and 0.46 ppm, and 0.20 and 0.41 ppm (dry weight) respectively. There was considerable overlap between levels suggesting that selenium status was not the only factor involved in the development of WMD.  相似文献   
40.
  • 1. The ecological recovery of streams from large‐scale perturbations, such as acidification, requires aquatic insects to disperse between catchments. While adults can usually fly, dispersal is seldom observed directly. Catches of insects in transects of traps perpendicular from streams suggest that lateral adult dispersal is limited. This paper evaluates whether this could explain limited biological recovery in streams recovering chemically from acidification.
  • 2. At the replicate Llyn Brianne experimental catchments (Wales), Malaise traps (2000) and benthic sampling (1985–2005) were used to appraise inter‐catchment dispersal in acid‐sensitive Ephemeroptera, Plecoptera and Trichoptera. The results provide direct evidence for inter‐catchment dispersal: eight species from three Orders were caught as adults alongside acid streams where larvae never occurred in 21 years' benthic sampling.
  • 3. These data refute the hypothesis that limited dispersal per se explains delayed biological recovery from acidification in Welsh streams. Other factors affecting colonization (e.g. ‘propagule pressure’, mating or oviposition behaviour) and persistence (e.g. continued acid episodes) must be involved, with the first of these possibilities still poorly understood. These data add to a growing body of literature illustrating insect dispersal between catchments, and they have wider relevance to the recovery and restoration of river ecosystems following basin‐scale impacts.
Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
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