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BACKGROUND: Macrolide polyene antibiotics possess potent broad‐spectrum antifungal properties. Use of these agents in the field or in controlled environments is impeded by their poor water solubility and susceptibility to oxidation‐ and/or light‐induced degradation. While typically used for human disease therapy, there is potential to expand the utility of polyene macrolide antibiotics, such as amphotericin B, for control of fungal disease infestation in agricultural settings. Thus, the susceptibility of this antibiotic to exposure‐induced activity loss was evaluated. RESULTS: Incubation of the prototype polyene amphotericin B (AMB) with phospholipid vesicles and apolipoprotein A‐I results in the formation of nanoscale complexes, termed nanodisks (NDs), capable of solubilizing significant quantities of AMB. To evaluate whether AMB incorporation into NDs conferred protection against light‐ or oxidation‐induced damage, yeast growth inhibition assays were conducted. Compared with AMB solubilized in detergent micelles, AMB incorporated into NDs was protected from damage caused by exposure to UV light as well as by KMnO4‐induced oxidation. Furthermore, AMB‐NDs inhibited growth of the turfgrass fungus Marasmius oreades Fr. CONCLUSION: Results suggest that this water‐soluble formulation of a natural, biodegradable, antifungal agent represents a potential cost‐effective, non‐toxic and environmentally friendly substitute for chemical agents currently employed to control a range of fungal infestations. Copyright © 2009 Society of Chemical Industry 相似文献
263.
Megan C. Sabal Kate Richerson Paul Moran Taal Levi Vanessa J. Tuttle Michael Banks 《Fish and Fisheries》2023,24(6):910-923
Fisheries bycatch impacts marine species globally and understanding the underlying ecological and behavioural mechanisms could improve bycatch mitigation and forecasts in novel conditions. Oceans are rapidly warming causing shifts in marine species distributions with unknown, but likely, bycatch consequences. We examined whether thermal and diel depth-use behaviours influenced bycatch of a keystone species (Chinook salmon; Oncorhynchus tshawytscha, Salmonidae) in the largest fishery on the US West Coast (Pacific hake; Merluccius productus, Merlucciidae) with annual consequences in a warming ocean. We used Generalized Additive Models with 20 years of data including 54,509 hauls from the at-sea hake fishery spanning Oregon and Washington coasts including genetic information for five salmon populations. Our results demonstrate that Chinook salmon bycatch rates increased in warm ocean years explained by salmon depth-use behaviours. Chinook salmon typically occupy shallower water column depths compared to hake. However, salmon moved deeper when sea surface temperatures (SSTs) were warm and at night, which increased overlap with hake and exacerbated bycatch rates. We show that night fishing reductions (a voluntary bycatch mitigation strategy) are effective in reducing salmon bycatch in cool SSTs by limiting fishing effort when diel vertical movements bring salmon deeper but becomes less effective in warm SSTs as salmon seek deeper thermal refugia during the day. Thermal and diel behaviours were more pronounced in southern compared with northern salmon populations. We provide mechanistic support that climate change may intensify Chinook salmon bycatch in the hake fishery and demonstrate how an inferential approach can inform bycatch management in a changing world. 相似文献
264.
Megan K. Schall Timothy Wertz Geoffrey D. Smith Vicki S. Blazer Tyler Wagner 《Fisheries Management and Ecology》2019,26(6):590-599
Smallmouth bass, Micropterus dolomieu Lacepède, movement dynamics were investigated in a connected mainstem river‐tributary system. Smallmouth bass moved large distances annually (n = 84 fish, average = 24.6 ± 25.9 km, range = 0.03 to 118 km) and had three peak movement periods (pre‐spawn, post‐spawn and overwintering). Movement into and out of tributaries was common, but the movement between mainstem river and tributary habitats varied among tagging locations and season. In general, a large proportion of fish that were tagged in tributaries moved out of the tributaries after spawning (22/30 fish). Because of the importance of fish movement patterns on population dynamics, the observed individual variability in movement, quantified using a hierarchical model, and the potential for long‐distance movements are important considerations for smallmouth bass conservation and management. In addition, mainstem river‐tributary connectivity appears to play an important role for smallmouth bass during key life history events. 相似文献
265.
The western and central Pacific Ocean (WCPO) tuna fishery is one of the world's largest in terms of both catch volume and value, providing over half of global tuna catch with a landed value of US $5.84 billion in 2017. Fishing is conducted by both large‐ and small‐scale fleets, with fisheries subsidies disproportionately benefiting the former. The primary objective of this study was to determine the optimal distribution of effort between two large‐scale fisheries (LSF) and two small‐scale fisheries (SSF) in the WCPO under three scenarios: to maximize industry benefits, minimize subsidization or maximize food supply. The objective was approached using a bioeconomic game‐theoretic model. Results indicate opposite distributions of effort to maximize industry benefits (all fishing conducted by LSF) or to minimize subsidization (all fishing by SSF), with more balanced effort distributions to maximize food supply. Total value of capacity‐enhancing subsidies in optimal scenarios ranged from $1.4 billion when industry benefits were maximized to $0.2 billion when subsidization was minimized. Investigation of suboptimal scenarios reveals the flexibility of these results, with wide ranges in outputted state variables for a given goal. Difficulty was encountered in modelling the SSF sector due to data deficiencies, a well‐recognized issue in managing SSF. Investments towards “data equity” to help ensure that management decision‐making can properly account for the SSF sector would be useful. This study has implications for the objectives we set in fisheries management, and the potential trade‐offs, often value‐driven in nature, that we must make explicit in that management. 相似文献
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David A. Oluwadare Helen E. Carney Mosharraf H. Sarker Christopher J. Ennis 《植物养料与土壤学杂志》2020,183(2):136-143
Soil fertilization with trace‐metal rich organic fertilizers such as Fucus serratus seaweed may be an effective way to combat micronutrient deficiency. In this study the kinetics of zinc release from Fucus serratus seaweed was investigated in a packed soil column leaching experiment over 1,776 h. The release of zinc from control (soil only) and treatment (soil + seaweed; equivalent zinc application rate of 1.42 kg ha?1) columns, measured by ICP‐MS, demonstrated two distinct release stages. The cumulative zinc release data for each phase were fitted to five kinetic models: zero order, first order, Elovich, power function and parabolic diffusion. In the first stage (0–400 hours) the release of zinc from both control and treatment was best described by a parabolic rate law, indicating release of zinc from a soluble soil reservoir. In the second stage (400–1,776 h) zinc release followed a zero order rate law indicative of slow release from an essentially insoluble reservoir. The modelled difference between the amount of zinc released from treatment and control columns in stage 1 (230 ± 11 µg) represented the total amount of zinc added via seaweed. The parabolic rate constant for seaweed zinc release was 12.09 µg g?1 h?0.5. In summary, the addition of F. serratus to soil is a viable source of labile zinc and a low cost agronomic option for mitigating zinc deficiency in soils. 相似文献
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Nathan J. Robinson Peter G. Dahlhaus Megan Wong Andrew MacLeod Dean Jones Cam Nicholson 《Soil Use and Management》2019,35(1):94-104
Soil data form the basis of soil information systems across the globe. Soil information needs, and the questions posed by users, are likely to evolve in response to advances in technology in this era of Big Data. This poses a challenge to the pedological community which is already experiencing a decline in soil knowledge and expertise. With a decrease in soil data collection by governments, it is timely to reconsider how and what soil information should be provided to future users. A public–private partnership is advocated to deliver timely and accessible soil information to users. Two public–private provisioning programs are presented, and advantages and considerations for sharing soil data and information amongst industry, government, research organizations, service providers and land managers for these are discussed. Interoperable, open‐source and agreed soil community standards are used to present soil data and information through spatial web portals with tools for interpretation of soil data for public and private beneficiaries. 相似文献
270.