提高鸡生产性能的多学科措施     

Sarah Mellor  张道凌  蔡迎辉 《国外畜牧学(猪与禽)》2007,27(5):27-29

第二届世界营养论坛在奥地利首都维也纳举行,来自动物科学所有领域的国际相关人士云集一堂,讨论如何最大限度地利用已经取得的遗传进展,如何处理好现在和将来的其它问题。  相似文献   

Computed tomography of testicular torsion in a juvenile dog with unilateral cryptorchidism     

Sarah A. Slaughter  Andrew D. Eitzer  Sara E. Tolliver  Sarah N. Holman  Sara A. Colopy  Seamus E. Hoey  Samantha J. Loeber 《The Canadian veterinary journal. La revue veterinaire canadienne》2022,63(5):515

A 14-week-old male unilaterally cryptorchid Clumber spaniel was presented for acute lethargy. Physical examination revealed abdominal pain, and a single testis was palpated in the scrotum. Abdominal ultrasound and computed tomography (CT) revealed a poorly vascularized, ovoid structure immediately caudal to the left kidney with scant regional peritoneal effusion. Left intra-abdominal testicular torsion was confirmed at surgery, and routine cryptorchidectomy was performed. The patient recovered uneventfully from anesthesia and surgery.Key clinical message:The most common CT characteristics of testicular torsion were present in this case and correlated well with sonographic findings to allow for rapid, accurate diagnosis and surgical planning of unilateral, non-neoplastic, intra-abdominal cryptorchid testicular torsion in a juvenile dog. Contrast enhanced CT facilitated accurate localization of the undescended testis and evaluation of testicular perfusion and may be a useful alternative to ultrasound for diagnosing testicular torsion, especially in indeterminate cases.  相似文献   

Fijian adolescents’ understanding and evaluation of climate change: Implications for enabling effective future adaptation          下载免费PDF全文

Bridie Scott‐Parker  Roselyn Kumar 《Asia Pacific viewpoint》2018,59(1):47-59

Pacific Island countries are particularly vulnerable to future manifestations of climate change due to high coastline‐to‐land‐area ratios, and high dependence of inhabitants on natural ecosystems. While everyone in the Pacific Islands should participate in climate change adaptation activities, it is the young people, given they are the generation likely to not only bear the burden of climate change, but to lead and live effective climate change adaptation activities and strategies specific to their region, the involvement of youth is critical. Pacific Island youths are often marginalised within traditional decision‐making hierarchies, therefore they are typically excluded from participating in meaningful discussions at community and government levels. Discussions were held with 30 adolescents aged 14–18 years in Fiji to explore knowledge and experiences regarding climate change. Participants revealed their dismay at their inability to talk to family – who they consider are not doing enough – about what they consider as appropriate responses to climate change, recommending the help of an authoritative outsider who could speak to their community leaders and family. Discussions also revealed that Fijian youth could not distinguish between changes in the climate and normal weather events, attesting to the importance of climate‐change education and awareness‐raising efforts within the Pacific Islands more generally.  相似文献   

Optimizing aphid biocontrol with the predator Aphidoletes aphidimyza,based on biology and ecology     

Franois‐Xavier Boulanger  Sarah Jandricic  Karel Bolckmans  Felix L Wckers  Apostolos Pekas 《Pest management science》2019,75(6):1479-1493

Aphidoletes aphidimyza is one of the most important predators used in the augmentative biological control of aphids, key pests of many crops worldwide. Adult females are very efficient in locating aphid infestations over a relatively long range, up to 45 m, and deposit eggs near or within aphid colonies. The predatory larvae are aphid generalists preying on several agriculturally important aphid species. The successful use of this biocontrol agent in agricultural systems depends on several biotic and abiotic factors. Among biotic factors, aphid species, plant structure, interspecific competition and intraguild predation may significantly impact the predator´s population dynamics. Key abiotic conditions include day lengths (above a critical threshold to prevent diapause), availability of mating sites in the crop, temperature (above 15 °C to enable egg laying), air relative humidity (above 70%) and availability of pupation sites. Although several successes have been reported in open field crops with naturally occurring or released populations, commercial releases are primarily used in protected crops. Optimized emergence boxes combining provisioning of food sources for the adults, integration with the technological advances that occurred in the greenhouse environment lately, insights into the nutritional ecology in open field crops and exploration of the genetic variability are proposed as future directions to improve adoption and efficacy of A. aphidimyza in crop protection. © 2018 Society of Chemical Industry  相似文献   

Eco‐efficiency as a strategy for optimizing the sustainability of pest management     

Roger D Magarey  Sarah SH Klammer  Thomas M Chappell  Christina M Trexler  Godshen R Pallipparambil  Ernie F Hain 《Pest management science》2019,75(12):3129-3134

Agricultural industrialization and the subsequent reliance on pesticides has resulted in numerous unintended consequences, such as impacts upon the environment and by extension human health. Eco‐efficiency is a strategy for sustainably increasing production, while simultaneously decreasing these externalities on ecological systems. Eco‐efficiency is defined as the ratio of production to environmental impacts. It has been widely adopted to improve chemical production, but we investigate the challenges of applying eco‐efficiency to pesticide use. Eco‐efficiency strategies include technological innovation, investment in research and development, improvement of business processes, and accounting for market forces. These components are often part of integrated pest management (IPM) systems that include alternatives to pesticides, but its implementation is often thwarted by commercial realities and technical challenges. We propose the creation and adoption of an eco‐efficiency index for pesticide use so that the broad benefits of eco‐efficient strategies such as IPM can be more readily quantified. We propose an index based upon the ratio of crop yield to a risk quotient (RQ) calculated from pesticide toxicity. Eco‐efficiency is an operational basis for optimizing pest management for sustainability. It naturally favors adoption of IPM and should be considered by regulators, researchers, and practitioners involved in pest management. © 2019 Society of Chemical Industry  相似文献   

The homogenizing influence of agriculture on forest bird communities at landscape scales     

Endenburg  Sarah  Mitchell  Greg W.  Kirby  Patrick  Fahrig  Lenore  Pasher  Jon  Wilson  Scott 《Landscape Ecology》2019,34(10):2385-2399

Landscape Ecology - Agricultural expansion is a principal driver of biodiversity loss, but the impacts on community assembly in agro-ecosystems are less clear, especially across regional scales at...  相似文献   

Agriculturally productive yet biodiverse: human benefits and conservation values along a forest-agriculture gradient in Southern Ethiopia     

Baudron  Frédéric  Schultner  Jannik  Duriaux  Jean-Yves  Gergel  Sarah E.  Sunderland  Terry 《Landscape Ecology》2019,34(2):341-356

Landscape Ecology - It remains unclear how agricultural landscapes can best serve multiple purposes such as simultaneously maintaining agricultural productivity and conserving biodiversity. Our...  相似文献   

Physicochemical characteristics of onion (Allium cepa L.) tissues     

Ng A  Parker ML  Parr AJ  Saunders PK  Smith AC  Waldron KW 《Journal of agricultural and food chemistry》2000,48(11):5612-5617

The structure and mechanical properties of onions are important factors affecting their textural quality. The onion bulb consists of several layers of pigmented, papery scales surrounding fleshy storage scales that comprise an upper epidermis, an intermediate parenchyma tissue, and a lower epidermis. The purpose of this study was to examine the chemical composition of cell walls from the papery scales and outer fleshy scales of onion (Allium cepa L. cv. Sturon) in relation to their mechanical properties. Cell-wall material (CWM) was prepared from the component tissues and analyzed for its carbohydrate and phenolic composition. The CWMs were rich in uronic acid and glucose, with smaller quantities of arabinose, galactose, and xylose. In the fleshy scales, the lower epidermis contained relatively more galactose-rich pectic polysaccharides, whereas the upper epidermis and the papery scales contained virtually no galactose. Analysis of mechanical properties showed that the order of strength of the tissues was papery scales > fleshy scales, which were in the order lower epidermis > upper epidermis > intermediate parenchyma. The upper epidermis of fleshy scales was stronger in the vertical than the horizontal direction, and both orientations showed negligible notch sensitivity. Cyclohexane-trans-1,2-diaminetetraacetate-induced vortex-induced cell separation of the intermediate layer of fleshy scales indicated that calcium cross-linking may play an important role in cell-cell adhesion. A small but significant amount of ferulic acid was found in the walls, predominantly in the thick cuticle of the lower epidermis of fleshy scales. Alkali-labile wall-bound flavonoids were also detected.  相似文献   

淹水土壤有机酸积累与秸秆碳氮比及氮供应的关系   总被引：21，自引：0，他引：21  

单玉华  蔡祖聪  韩勇  Sarah E Johnson  Roland J Buresh 《土壤学报》2006,43(6):941-947

有机酸积累和毒害是稻田秸杆还田中受到广泛关注的问题。本文以水稻与小麦秸杆为材料，采用淹水培养研究了甲酸、乙酸、丙酸及丁酸在士壤中的积累及其与秸秆碳氮比、氮肥添加量的关系。结果表明，在不施用氮肥的情况下。随秸秆用量的增加，秸秆处理的有机酸积累均显著增多。与稻秸处理相比，麦秸处理的有机酸（尤其足丙酸）积累量显著较高，土壤溶液中NH4^＋浓度显著较低。加入尿素明显减少有机酸积累，促进CH4排放，但对CO2的排放无显著影响；氮素的影响在麦秸处理中表现的尤为明显。上述结果说明麦秸的高碳氮比增加了无机氮的生物固定，抑制有机酸向CH4转化，从而导致麦秸处理有机酸积累量高于稻秸处理。施用氮肥是减少麦秸还田后有机酸积累的有效措施之一，但此措施将可能促进CH4的排放。  相似文献   

Identification and quantification of a marker compound for 'pepper' aroma and flavor in shiraz grape berries by combination of chemometrics and gas chromatography-mass spectrometry     

Parker M  Pollnitz AP  Cozzolino D  Francis IL  Herderich MJ 《Journal of agricultural and food chemistry》2007,55(15):5948-5955

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