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1.
Much effort has been devoted to developing, constructing and refining fish passage facilities to enable target species to pass barriers on fluvial systems, and yet, fishway science, engineering and practice remain imperfect. In this review, 17 experts from different fish passage research fields (i.e., biology, ecology, physiology, ecohydraulics, engineering) and from different continents (i.e., North and South America, Europe, Africa, Australia) identified knowledge gaps and provided a roadmap for research priorities and technical developments. Once dominated by an engineering‐focused approach, fishway science today involves a wide range of disciplines from fish behaviour to socioeconomics to complex modelling of passage prioritization options in river networks. River barrier impacts on fish migration and dispersal are currently better understood than historically, but basic ecological knowledge underpinning the need for effective fish passage in many regions of the world, including in biodiversity hotspots (e.g., equatorial Africa, South‐East Asia), remains largely unknown. Designing efficient fishways, with minimal passage delay and post‐passage impacts, requires adaptive management and continued innovation. While the use of fishways in river restoration demands a transition towards fish passage at the community scale, advances in selective fishways are also needed to manage invasive fish colonization. Because of the erroneous view in some literature and communities of practice that fish passage is largely a proven technology, improved international collaboration, information sharing, method standardization and multidisciplinary training are needed. Further development of regional expertise is needed in South America, Asia and Africa where hydropower dams are currently being planned and constructed.  相似文献   
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Causes and criteria of resistance to air pollution in Norway spruce. 1. Morphological and anatomical resistance. Pollution resistance of selected visibly resistant clones is not due to environmental causes or to length of the growing season. Between the resistant and other clones there are significant differences in morphology and anatomy of the needles. The average length, width and weight of the needles of resistant spruce grafts arc greater than those of none resistant. The resistant grafts have more stomata and, at least in winter, lower permeability of needle tissue to gases.  相似文献   
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This is the first report and characterization of Bursaphelenchus sexdentati and the first official report of the presence of the genus Bursaphelenchus in Israel. This species was isolated from Orthotomicus erosus (Coleoptera: Scolytinae) found on Pinus halepensis in the Judean foothills in Israel. Nematodes collected from insect galleries were reared on fungal cultures and identified based on morphological diagnostic characters for the genus Bursaphelenchus. Sequencing analyses of the Internal Transcribed Spacer (ITS) region, small subunit (SSU) and large subunit (LSU) of ribosomal DNA confirmed the identification of this nematode species collected from wood and directly from the insect body.  相似文献   
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The Mediterranean spearfish (Tetrapturus belone) is one of the least‐studied istiophorid billfishes, with little known of its biology, ecology, and behavior. To assess the species’ movement and thermal niche, we analyzed telemetry data from, to our knowledge, the first and only Mediterranean spearfish ever outfitted with a pop‐up satellite archival transmitting tag. Throughout a 29‐day deployment during July and August 2015, the fish travelled in Italian waters of the Tyrrhenian and Ligurian Seas, spending on average 93% of each 24‐hr period above 30 m and exhibiting a diel activity pattern comprised of daytime vertical movement and nighttime near‐surface residency. The preferred thermal niche was 26–28°C, but the spearfish experienced temperatures as low as 14.2°C during descents. Vertical distribution was limited throughout the deployment with more time spent at depth in areas where the thermocline was comparatively deeper and weaker, consistent with habitat compression experienced by other billfishes.  相似文献   
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With respect to bacterial natural products, a significant outcome of the genomic era was that the biosynthetic potential in many microorganisms surpassed the number of compounds isolated under standard laboratory growth conditions, particularly among certain members in the phylum Actinobacteria. Our group, as well as others, investigated interspecies interactions, via co-culture, as a technique to coax bacteria to produce novel natural products. While co-culture provides new opportunities, challenges exist and questions surrounding these methods remain unanswered. In marine bacteria, for example, how prevalent are interspecies interactions and how commonly do interactions result in novel natural products? In an attempt to begin to answer basic questions surrounding co-culture of marine microorganisms, we have tested both antibiotic activity-based and LC/MS-based methods to evaluate Micromonosporaceae secondary metabolite production in co-culture. Overall, our investigation of 65 Micromonosporaceae led to the identification of 12 Micromonosporaceae across three genera that produced unique metabolites in co-culture. Our results suggest that interspecies interactions were prevalent between marine Micromonosporaceae and marine mycolic acid-containing bacteria. Furthermore, our approach highlights a sensitive and rapid method for investigating interspecies interactions in search of novel antibiotics, secondary metabolites, and genes.  相似文献   
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德国及蒙古沙棘品种无性系生物学和观赏性价值评估   总被引:1,自引:0,他引:1  
沙棘由于其有丰富的内含物和多方面的用途正被作为"新兴水果"而赢得了人们越来越多的重视和喜爱.通过在柏林Baumschulenweg的育种工作,到目前为止,已经育成不同成熟期的5个雌性和4个雄性沙棘品种.更多的由欧洲和蒙古原生种产生的杂交选育工作仍在进行中.将这些无性系按照其生物学和果实性状进行评估.就单个性状来讲,各品种之间的差异非常大(比如维生素的含量在17~340mg/100g之间变动,胡萝卜素的变动范围为6.5~23.8mg/100g).这表明,进一步的育种改良完全有可能.所有用于比较的沙棘品种由在德累斯顿Pillnitz进行的育种工作获得,这些品种将被进一步研究.为了保险起见,以及为了解决后来有可能产生的育种及植物病理学方面的问题,必须尽可能保存现有的所有的某一品种的基因多样性.为此目的,由国家资助扶持的基因库的建立是很有必要的.  相似文献   
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