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排序方式: 共有1148条查询结果,搜索用时 15 毫秒
1.
Bonaventure A. Omondi Misheck M. Soko Innocent Nduwimana Ronald T. Delano Celestin Niyongere Alice Simbare Donald Kachigamba Charles Staver 《Plant pathology》2020,69(9):1754-1766
The removal of infected individuals is a common practice in the management of plant disease outbreaks. It minimizes the contact between healthy individuals and inoculum sources by reducing the infectious window of contaminated individuals. This requires early detection and consistent removal at landscape scale. Roguing of mats with symptoms of banana bunchy top disease (BBTD) in Cavendish banana production systems has been tested in Australia, using trained personnel, but has never been tested in smallholder systems. We studied the effectiveness of long-term consistent roguing in prolonging the productivity of banana orchards under smallholder farming systems in highland banana and plantain dominated production systems in Africa. We assessed the possibility of low-risk seed sourcing from the managed plots. Roguing reduced BBTD incidence to 2% in managed farmer fields and to 10% in experimental field plots, while a nonmanaged field eventually collapsed in the same period. With roguing, new infections decreased monthly compared to an exponential increase in a nonmanaged field. The emergence of new infections in both managed and nonmanaged farms followed a seasonal cycle. BBTD managed plots were a source of low-risk seed for replacing the rogued mats in the same fields, but perhaps not safe for use in nonendemic areas. We conclude that it is possible for smallholder farmers to recover and maintain banana productivity with rigorous roguing, which would entail early identification of symptoms and early removal of diseased mats. Studies are needed on the intensity of roguing under different disease and production conditions. 相似文献
2.
Bertrand C. Y. Collard Joseph C. Beredo Bert Lenaerts Rhulyx Mendoza Ronald Santelices Vitaliano Lopena 《Plant Production Science》2017,20(4):337-352
Rice production needs to increase in the future in order to meet increasing demands. The development of new improved and higher yielding varieties more quickly will be needed to meet this demand. However, most rice breeding programmes in the world have not changed in several decades. In this article, we revisit the evidence in favour of using rapid generation advance (RGA) as a routine breeding method. We describe preliminary activities at the International Rice Research Institute (IRRI) to re-establish RGA on a large scale as the main breeding method for irrigated rice breeding. We also describe experiences from the early adoption at the Bangladesh Rice Research Institute. Evaluation of RGA breeding lines at IRRI for yield, flowering time and plant height indicated transgressive segregation for all traits. Some RGA lines were also higher yielding than the check varieties. The cost advantages of using RGA compared to the pedigree method were also empirically determined by performing an economic analysis. This indicated that RGA is several times more cost effective and advantages will be realized after 1 year even if facilities need to be built. Based on our experience, and previous independent research empirically testing the RGA method in rice, we recommend that this method should be implemented for routine rice breeding in order to improve breeding efficiency. 相似文献
3.
Holding wild Snow crab,Chionoecetes opilio: effects of stocking density and feeding on survival and injury 下载免费PDF全文
Sten Ivar Siikavuopio Philip James Bjørn Ronald Olsen Tor Evensen Atle Mortensen Stein Harris Olsen 《Aquaculture Research》2017,48(4):1590-1595
In this study the effects of different stocking densities on survival, injury and weight of captive male snow crab were examined. The first experiment (I) was carried out in square plastic tanks (700 L) with stocking densities of 100 (L), 150 (M) and 200 kg m?3 (H) for 30 days. In a second experiment (II) snow crabs were kept at a stocking density of 50 kg m?3 and were either fed (F) or not fed (S) for the same period of 35 days. The last experiment (III), was carried out with stocking densities of 25 kg m?3 for 21 days with two groups, one with inactivated claw and one without rubber bands, with three replicates per treatment. In the first experiment mortality (H = 27, M = 26 and L = 36%) and occurrence of injuries (H = 27, M = 20 and L = 16%) were high in all groups. The weight loss during the experimental period was; H = 15.3, M = 10.9 and L = 15.5 g, and was not significant different between the groups. In experiment II the mortality (F = 13% and S = 14%) and injuries were lower (F = 12% and S = 17%). The average weight increased in the fed treatment and decreased in the starved treatments. In the last experiment there was no mortality in any of the groups and the levels of injury were low (5% and 7%). The results show that adult male snow crab cannot be stored at densities equal to or higher than 25 kg m?3 for 3 weeks without risk of mortality. 相似文献
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Ruscena WIEDERHOLT Anne M. TRAINOR Nicole MICHEL Patrick D. SHIREY Ronald R. SWAISGOOD Doug TALLAMY Susan C. COOK‐PATTON 《Integrative zoology》2015,10(5):436-452
In its 40‐year history, the science of conservation has faced unprecedented challenges in terms of environmental damage and rapid global change, and environmental problems are only increasing as greater demands are placed on limited natural resources. Conservation science has been adapting to keep pace with these changes. Here, we highlight contemporary and emerging trends and innovations in conservation science that we believe represent the most effective responses to biodiversity threats. We focus on specific areas where conservation science has had to adjust its approach to address emerging threats to biodiversity, including habitat destruction and degradation, climate change, declining populations and invasive species. We also document changes in attitudes, norms and practices among conservation scientists. A key component to success is engaging and maintaining public support for conservation, which can be facilitated through the use of technology. These recent trends in conservation and management are innovative and will assist in optimizing conservation strategies, increasing our leverage with the general public and tackling our current environmental challenges. 相似文献
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Charlotte M. Keenan Julia F. Baker Alys E. Bradley Dawn G. Goodman Takanori Harada Ronald Herbert Wolfgang Kaufmann Rupert Kellner Beth Mahler Emily Meseck Thomas Nolte Susanne Rittinghausen John Vahle Katsuhiko Yoshizawa 《Journal of toxicologic pathology》2015,28(1):51-53
The INHAND Proposal (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) has been operational since 2005. A Global Editorial Steering Committee (GESC) manages the overall objectives of the project and the development of harmonized terminology for each organ system is the responsibility of the Organ Working Groups (OWG), drawing upon experts from North America, Europe and Japan.Great progress has been made with 9 systems published to date – Respiratory, Hepatobiliary, Urinary, Central/Peripheral Nervous Systems, Male Reproductive and Mammary, Zymbals, Clitoral and Preputial Glands in Toxicologic Pathology and the Integument and Soft Tissue and Female Reproductive System in the Journal of Toxicologic Pathology as supplements and on a web site – www.goreni.org. INHAND nomenclature guides offer diagnostic criteria and guidelines for recording lesions observed in rodent toxicity and carcinogenicity studies. The guides provide representative photo-micrographs of morphologic changes, information regarding pathogenesis, and key references. During 2012, INHAND GESC representatives attended meetings with representatives of the FDA Center for Drug Evaluation and Research (CDER), Clinical Data Interchange Standards Consortium (CDISC), and the National Cancer Institute (NCI) Enterprise Vocabulary Services (EVS) to begin incorporation of INHAND terminology as preferred terminology for SEND (Standard for Exchange of Nonclinical Data) submissions to the FDA. The interest in utilizing the INHAND nomenclature, based on input from industry and government toxicologists as well as information technology specialists, suggests that there will be wide acceptance of this nomenclature. The purpose of this publication is to provide an update on the progress of INHAND. 相似文献
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Microsporidia are a ubiquitous group of obligate intracellular parasites that infect all major animal groups. Enterocytozoon bieneusi is the most commonly identified Microsporidia in humans and has also been reported worldwide in animals with importance in veterinary medicine (e.g. cats, dogs, horses, cattle and pigs). The identification of E. bieneusi in animals has raised the question of the importance of animal reservoirs in the epidemiology of this pathogen, and the implications of the infection with this pathogen in infected animals. Considerable genetic diversity within E. bieneusi has been found with over 90 genotypes identified based on the ITS nucleotide sequence of E. bieneusi spores recovered from the feces of infected humans and animals. Both host-adapted E. bieneusi genotypes with narrow host ranges and potentially zoonotic genotypes with wide host specificity have been identified. The information presented in this review should be useful in understanding the taxonomy, epidemiology, zoonotic potential, and importance in public health of E. bieneusi. 相似文献
10.
高等植物细胞周期是细胞生物学上的重要研究领域。细胞周期受遗传和发育影响因素的调控。本文综述高等植物细胞周期中涉及到细胞周期关卡GO-G1-S期和G2-M期的激素调控。最新研究成果证明玉米素、腺嘌呤、激动素、赤霉素和脱落酸等通过细胞周期蛋白依赖性蛋白激酶及细胞周期关卡的脱磷酸化控制细胞周期。植物D-型细胞周期蛋白也已被证明在细胞周期调控中起关键作用。本文有关细胞周期的研究综述对植物细胞和发育生物学研究有参考价值。图3参61。 相似文献