N-acetylcysteine manipulation fails to elicit an increase in glutathione in a teleost model     

Kim Birnie-Gauvin  Martin H. Larsen  Kim Aarestrup  William G. Willmore  Steven J. Cooke 《Fish physiology and biochemistry》2018,44(1):137-142

Levels of oxidative stress can be affected by a range of compounds including toxins and pharmaceuticals. Antioxidants are important protective compounds which counteract the damaging effects of oxidative stress. Glutathione (GSH) is one of the main antioxidants for many organisms and can be synthesized from administered N-acetylcysteine (NAC). NAC has therefore often been used in a wide range of taxa to manipulate levels of GSH. Our objective was to validate this approach in a wild temperate teleost fish model, the brown trout (Salmo trutta). We used intracoelomic injections of NAC in saline and vegetable shortening, at two different concentrations (100 and 400 mg/kg), with the appropriate controls and shams, under controlled laboratory settings. We found that NAC failed to elicit an increase in GSH over three time periods and concluded that NAC is not an effective method to enhance GSH levels in teleost fish using the concentrations and vehicles tested here. We emphasize the importance of validation studies across all new species/taxa when possible and suggest that more investigation is required with regard to NAC manipulation in fish if this approach is to be used.  相似文献   

The future of fish passage science,engineering, and practice          下载免费PDF全文

Ana T. Silva  Martyn C. Lucas  Theodore Castro‐Santos  Christos Katopodis  Lee J. Baumgartner  Jason D. Thiem  Kim Aarestrup  Paulo S. Pompeu  Gordon C. O'Brien  Douglas C. Braun  Nicholas J. Burnett  David Z. Zhu  Hans‐Petter Fjeldstad  Torbjørn Forseth  Nallamuthu Rajaratnam  John G. Williams  Steven J. Cooke 《Fish and Fisheries》2018,19(2):340-362

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   

Simulating long-term effect of Hyrcanian forest loss on phosphorus loading at the sub-watershed level     

Fatemeh RAJAEI  Abbas E SARI  Abdolrassoul SALMANMAHINY  Timothy O RANDHIR  Majid DELAVAR  Reza D BEHROOZ  Alireza M BAVANI 《干旱区科学》2018,10(3):457-469

Conversion of forest land to farmland in the Hyrcanian forest of northern Iran increases the nutrient input, especially the phosphorus(P) nutrient, thus impacting the water quality. Modeling the effect of forest loss on surface water quality provides valuable information for forest management. This study predicts the future impacts of forest loss between 2010 and 2040 on P loading in the Tajan River watershed at the sub-watershed level. To understand drivers of the land cover, we used Land Change Modeler(LCM) combining with the Soil Water Assessment Tool(SWAT) model to simulate the impacts of land use change on P loading. We characterized priority management areas for locating comprehensive and cost-effective management practices at the sub-watershed level. Results show that agricultural expansion has led to an intense deforestation. During the future period 2010–2040, forest area is expected to decrease by 34,739 hm~2. And the areas of pasture and agriculture are expected to increase by 7668 and 27,071 hm~2, respectively. In most sub-watersheds, P pollution will be intensified with the increase in deforestation by the year 2040. And the P concentration is expected to increase from 0.08 to 2.30 mg/L in all of sub-watersheds by the year 2040. It should be noted that the phosphorous concentration exceeds the American Public Health Association′s water quality standard of 0.2 mg/L for P in drinking water in both current and future scenarios in the Tajan River watershed. Only 30% of sub-watersheds will comply with the water quality standards by the year 2040. The finding of the present study highlights the importance of conserving forest area to maintain a stable water quality.  相似文献   

Spawning site fidelity and apparent annual survival of walleye (Sander vitreus) differ between a Lake Huron and Lake Erie tributary          下载免费PDF全文

Todd A. Hayden  Thomas R. Binder  Christopher M. Holbrook  Christopher S. Vandergoot  David G. Fielder  Steven J. Cooke  John M. Dettmers  Charles C. Krueger 《Ecology of Freshwater Fish》2018,27(1):339-349

Fidelity to spawning habitats can maximise reproductive success of fish by synchronising movements to sites of previous recruitment. To determine the role of reproductive fidelity in structuring walleye Sander vitreus populations in the Laurentian Great Lakes, we used acoustic telemetry combined with Cormack–Jolly–Seber capture–recapture models to estimate spawning site fidelity and apparent annual survival for the Tittabawassee River in Lake Huron and Maumee River in Lake Erie. Walleye in spawning condition were tagged from the Tittabawassee River in Lake Huron and Maumee River in Lake Erie in 2011–2012. Site fidelity and apparent annual survival were estimated from return of individuals to the stream where tagged. Site fidelity estimates were higher in the Tittabawassee River (95%) than the Maumee River (70%) and were not related to sex or fish length at tagging. Apparent annual survival of walleye tagged in the Tittabawassee did not differ among spawning seasons but was higher for female than male walleye and decreased linearly as fish length increased. Apparent annual survival of walleye tagged in the Maumee River did not differ among spawning seasons but was higher for female walleye than male walleye and increased linearly as fish length increased. Greater fidelity of walleye tagged in the Tittabawassee River than walleye tagged in the Maumee River may be related to the close proximity to the Maumee River of other spawning aggregations and multiple spawning sites in Lake Erie. As spawning site fidelity increases, management actions to conserve population structure require an increasing focus on individual stocks.  相似文献   

Salty stories,fresh spaces: Lessons for aquatic protected areas from marine and freshwater experiences          下载免费PDF全文

Erin K. Loury  Shaara M. Ainsley  Shannon D. Bower  Ratana Chuenpagdee  Tracy Farrell  Amanda G. Guthrie  Sokrith Heng  Zau Lunn  Abdullah Al Mamun  Rodrigo Oyanedel  Steve Rocliffe  Suvaluck Satumanatpan  Steven J. Cooke 《水产资源保护:海洋与淡水生态系统》2018,28(2):485-500

Evidence for selection pressure from resistant potato genotypes but not from fungicide application within a clonal Phytophthora infestans population          下载免费PDF全文

J. S. Stellingwerf  S. Phelan  F. M. Doohan  V. Ortiz  D. Griffin  A. Bourke  R. C. B. Hutten  D. E. L. Cooke  S. Kildea  E. Mullins 《Plant pathology》2018,67(7):1528-1538

Insight into pathogen population dynamics provides a key input for effective disease management of the potato late blight pathogen Phytophthora infestans. Phytophthora infestans populations vary from genetically complex to more simple with a few clonal lineages. The presence or absence of certain strains of P. infestans may impact the efficacy of fungicides or host resistance. Current evidence indicates that genetically, the Irish populations of P. infestans are relatively simple with a few clonal lineages. In this study, P. infestans populations were genetically characterized based on samples collected at the national centre for potato breeding during the period 2012–16. The dominance of clonal lineages within this P. infestans population was confirmed and the potential selection pressure of fungicide treatment (2013–15) and host resistance (2016) on this clonal P. infestans population was then investigated. It was found that fungicide products did not notably affect the genetic structure of sampled populations relative to samples from untreated control plants. In contrast, samples taken from several resistant potato genotypes were found to be more often of the EU_13_A2 lineage than those taken from control King Edward plants or potato genotypes with low resistance ratings. Resistant potato varieties Sarpo Mira and Bionica, containing characterized R genes, were found to strongly select for EU_13_A2 strains.  相似文献   

Agricultural Exports Competitiveness of Pakistan in Global Market     

Majid Lateef  Tong Guang-ji  Muhammad Usman Riaz  Mazhir Nadeem Ishaq  Muhammad Abdullah  Zeeshan Ahmad 《东北农业大学学报(英文版)》2018,(2)

Agricultural sector is a major source of employment and export earnings for Pakistan. Exports of Pakistan are highly concentrated in agricultural products including cotton, rice, sugar and fruit. This study analyzed comparative and competitive advantages of the main agricultural products of Pakistan, i.e. cotton, rice and tangerines. Consumption patterns of top exporting countries in each category were also analyzed. Results revealed that Pakistan had strong competitiveness for export of these commodities. Strong potential for growth in the agricultural sector of Pakistan was found and it could be optimized to raise export earnings and meet the objectives of the strategic trade policy framework(STPF) 2015-2018 of Pakistan.  相似文献   

The effect of water-diesel emulsion usage on a tractor engine performance and emission     

Majid Azimi  Seyed Sajad Mirjavadi  Ehsan Davari  Mohammad Reza Seifi 《Russian Agricultural Sciences》2016,42(6):488-492

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Copper functionalization of polypropylene fabric surface in order to use in fog collectors     

Mojtaba Sarafpour  Mostafa Youssefi  Sayed Majid Mortazavi 《Fibers and Polymers》2016,17(12):2041-2046

Polypropylene fabrics were coated with copper particles using electroless plating, screen printing and wire arc spray coating techniques. Surface morphology of the fabrics was studied using optical and scanning electron microscopes (SEM). Furthermore, tensile strength, electrical conductivity, thermal conductivity, air permeability, water contact angle and fog collection efficiency of the coated fabrics were measured and the obtained results were analyzed. SEM micrographs showed that a very thin and uniform layer of copper deposited on the surface of the electroless plated polypropylene fibers. In the printed or spray coated fabrics the copper particles filled the spaces between yarns and fibers. The polypropylene electroless copper plated fabrics showed higher tensile strength, electrical conductivity, air permeability and thermal conductivity when compared with the fabrics coated with copper screen printed and copper spray coated fabrics. Finally, the obtained results showed that copper electroless plating could increase the fog collection efficiency of polypropylene fabrics considerably. As a conclusion, the surface modified copper electroless polypropylene fabrics are good candidates for fog collection in appropriate regions which need further investigations.  相似文献   

Genetic analysis of resistance to tomato late blight in Solanum pimpinellifolium accession PI 163245          下载免费PDF全文

Erik W. Ohlson  Majid R. Foolad 《Plant Breeding》2016,135(3):391-398

Late blight (LB), caused by Phytophthora infestans, is one of the most devastating diseases of tomato (Solanum lycopersicum) worldwide. Due to the emergence of new and aggressive P. infestans isolates, identifying new genetic resistance to LB is a priority in tomato breeding. Recently, we reported the identification of several Solanum pimpinellifolium accessions with strong LB resistance. In this study, we investigated the utility of resistant accession PI 163245 for tomato breeding by examining heritability (h²) of resistance and the response to selection for resistance. Estimates of h² based on F₂ : F₃ and F₃ : F₄ parent : offspring correlation analyses averaged 0.79 and 0.94, respectively, suggesting the heritable nature of LB resistance in PI 163245. Analysis of response to selection for resistance from F₂ to F₄ generations indicated a realized h² of 0.63, confirming the utility of this resistance in tomato breeding. Two methods of estimating the minimum number of loci involved indicated the presence of one major resistance locus. Currently, genetic mapping and breeding efforts are underway to further confirm the viability of this accession for improving tomato LB resistance.  相似文献