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The placement of melatonin and of 5-hydroxytryptophol in the median eminence of castrated male rats is followed 5 days later by a significant decrease in pituitary stores of luteinizing hormone. Pituitary reserve of this hormone is also depleted after the implantation of melatonin, 5-hydroxytryptophol, and 5-methoxytryptophol in the reticular formation of the midbrain. It is suggested that these indole compounds, which are normally synthesized in the pineal gland, may intervene in the control of the secretion of luteinizing hormone, possibly by acting on specific receptors localized in the median eminence and in the midbrain. 相似文献
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The deposits of the Otjomongwa pan, southwestern Kalahari, Namibia, contain halite, thenardite and minor amounts of calcium-bearing sulfate minerals. The deposits show vertical variations in salt content, evaporite mineralogy and thenardite morphology, with similar patterns throughout the basin. The salt minerals were formed by evaporation of groundwater, within a groundmass of lacustrine deposits that did not contain synsedimentary evaporites. Lateral variations in total salt content are related to the direction of groundwater flow during a period with high groundwater levels following the end of lacustrine sedimentation in the pan basin. This was followed by a period without any groundwater influence that continues to the present. During this stage, leaching by rainwater occurred, resulting in changes in evaporite mineralogy, morphology and distribution. 相似文献
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Advocating a need for suitable breeding approaches to boost integrated pest management: a European perspective 
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下载免费PDF全文 Jay Ram Lamichhane Edward Arseniuk Piet Boonekamp Jerzy Czembor Veronique Decroocq Jérome Enjalbert Maria R Finckh Małgorzata Korbin Mati Koppel Per Kudsk Akos Mesterhazy Danuta Sosnowska Ewa Zimnoch‐Guzowska Antoine Messéan 《Pest management science》2018,74(6):1219-1227
Currently, European farmers do not have access to sufficient numbers and diversity of crop species/varieties. This prevents them from designing cropping systems more resilient to abiotic and biotic stresses. Crop diversification is a key lever to reduce pest (pathogens, animal pests and weeds) pressures at all spatial levels from fields to landscapes. In this context, plant breeding should consist of: (1) increased efforts in the development of new or minor crop varieties to foster diversity in cropping systems, and (2) focus on more resilient varieties showing local adaptation. This new breeding paradigm, called here ‘breeding for integrated pest management (IPM)’, may boost IPM through the development of cultivars with tolerance or resistance to key pests, with the goal of reducing reliance on conventional pesticides. At the same time, this paradigm has legal and practical implications for future breeding programs, including those targeting sustainable agricultural systems. By putting these issues into the context, this article presents the key outcomes of a questionnaire survey and experts' views expressed during an EU workshop entitled ‘Breeding for IPM in sustainable agricultural systems’. © 2017 Society of Chemical Industry 相似文献
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Identifying obstacles and ranking common biological control research priorities for Europe to manage most economically important pests in arable,vegetable and perennial crops 下载免费PDF全文
下载免费PDF全文 Jay Ram Lamichhane Monika Bischoff‐Schaefer Sylvia Bluemel Silke Dachbrodt‐Saaydeh Laure Dreux Jean‐Pierre Jansen Jozsef Kiss Jürgen Köhl Per Kudsk Thibaut Malausa Antoine Messéan Philippe C Nicot Pierre Ricci Jérôme Thibierge François Villeneuve 《Pest management science》2017,73(1):14-21
EU agriculture is currently in transition from conventional crop protection to integrated pest management (IPM). Because biocontrol is a key component of IPM, many European countries recently have intensified their national efforts on biocontrol research and innovation (R&I), although such initiatives are often fragmented. The operational outputs of national efforts would benefit from closer collaboration among stakeholders via transnationally coordinated approaches, as most economically important pests are similar across Europe. This paper proposes a common European framework on biocontrol R&I. It identifies generic R&I bottlenecks and needs as well as priorities for three crop types (arable, vegetable and perennial crops). The existing gap between the market offers of biocontrol solutions and the demand of growers, the lengthy and expensive registration process for biocontrol solutions and their varying effectiveness due to variable climatic conditions and site‐specific factors across Europe are key obstacles hindering the development and adoption of biocontrol solutions in Europe. Considering arable, vegetable and perennial crops, a dozen common target pests are identified for each type of crop and ranked by order of importance at European level. Such a ranked list indicates numerous topics on which future joint transnational efforts would be justified. © 2016 Society of Chemical Industry 相似文献
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