Non‐target‐site‐based resistance should be the centre of attention for herbicide resistance research: Alopecurus myosuroides as an illustration     

C DÉLYE  J A C GARDIN  K BOUCANSAUD  B CHAUVEL  C PETIT 《Weed Research》2011,51(5):433-437

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‘Universal’ PCR assays detecting mutations in acetyl‐coenzyme A carboxylase or acetolactate synthase that endow herbicide resistance in grass weeds     

C DÉLYE  F PERNIN  S MICHEL 《Weed Research》2011,51(4):353-362

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Assessing the Removal Efficiency of Zn, Cu, Fe and Pb in A Treatment Wetland Using Selective Sequential Extraction: A Case Study     

Catherine ChaguÉ-Goff 《Water, air, and soil pollution》2005,160(1-4):161-179

The accumulation and speciation of Zn, Cu, Fe and Pb in the sediments of an artificial surface-flow wetland used to treat domestic wastewater near Christchurch, New Zealand, were examined. Water metal concentrations and total suspended solid (TSS) content were determined at the inflow and outflow both in winter and summer, and metal concentrations were analysed in shoots and roots of selected plants. Water and sediment data suggest that the wetland is acting as a sink for Zn, Cu and Pb, while Fe uptake is minimal and the wetland appears to be releasing Fe in the winter. Metal concentrations in the most mobile fractions (exchangeable and bound to carbonates) are negligible. Cu is mostly associated with the organic/sulphide phase, whereas Zn and Pb show a strong affinity for hydroxides and organics/sulphides. A large fraction of all metals is also present in the residual phase, and is therefore unlikely to be released into the overlying water. Metal concentrations are below the low trigger values of the ANZECC sediment quality guidelines, except for Pb near the inflow. However, results of sequential extraction suggest that a significant proportion of Pb occurs in the detrital phase and is therefore not bio-available. Metal concentrations were higher in the roots than in the shoots of both Juncus sp. and Lythrum hyssopifolia. This study shows that, although metal concentrations are low, TSS and metals, except Fe, are effectively removed by the wetland system. The low removal rate of Fe is possibly due to the young age of the wetland and low loading rates.  相似文献   

Network interventions     

TW Valente 《Science (New York, N.Y.)》2012,337(6090):49-53

The term "network interventions" describes the process of using social network data to accelerate behavior change or improve organizational performance. In this Review, four strategies for network interventions are described, each of which has multiple tactical alternatives. Many of these tactics can incorporate different mathematical algorithms. Consequently, researchers have many intervention choices at their disposal. Selecting the appropriate network intervention depends on the availability and character of network data, perceived characteristics of the behavior, its existing prevalence, and the social context of the program.  相似文献   

Effect of dietary fish meal and fish oil replacement on lipogenic and lipoprotein lipase activities and plasma insulin in gilthead sea bream (Sparus aurata)     

L. BOURAOUI  J. SÁNCHEZ‐GURMACHES  L. CRUZ‐GARCIA  J. GUTIÉRREZ  L. BENEDITO‐PALOS  J. PÉREZ‐SÁNCHEZ  I. NAVARRO 《Aquaculture Nutrition》2011,17(1):54-63

The effects of a double replacement of fish oil (FO) and fish meal (FM) by dietary vegetable ingredients in juvenile gilthead sea bream (Sparus aurata L. 1758) on some indices of lipid metabolism and plasma insulin levels were analysed. Four experimental diets with a replacement of 75% of FM by plant proteins (PP) were administered. Added oil was either FO (75PP/FO diet), or a vegetable oil mix (VO), replacing 33%, 66% or 100% of FO (75PP/33VO, 75PP/66VO, 75PP/100VO diets). Another diet with 50% of substitution of FM by PP and with 100% of VO was also tested (50PP/100VO diet). Final body weight was similar in all diet groups, except for the 75PP/100VO group, which presented lower values. Circulating insulin levels increased with feed administration in all groups and no differences between diets were observed, with the exception of the 75PP/FO group, which presented higher plasma insulin values. In adipose tissue, glucose‐6‐phosphate dehydrogenase and malic enzyme activities decreased with the inclusion of vegetable oil, especially 5 h after feeding. Diet had no significant effect on the hepatic activity of either enzyme. Lipoprotein lipase activity decreased in white muscle and adipose tissue with the replacement of fish oil in 75PP diets, 5 h after feeding. In conclusion, the use of a combined replacement of fish oil and fish meal by vegetable ingredients in gilthead sea bream permits satisfactory growth, with moderate changes in tissue lipogenesis and lipid uptake.  相似文献   

Effects of different levels of plant proteins on the ongrowing of meagre (Argyrosomus regius) juveniles at low temperatures     

A. ESTÉVEZ  L. TREVIÑO  Y. KOTZAMANIS  I. KARACOSTAS  L. TORT  E. GISBERT 《Aquaculture Nutrition》2011,17(2):e572-e582

Four experimental diets with different inclusion levels of plant proteins and fish protein hydrolysates were compared with a commercial diet for meagre (Argyrosomus regius) ongrowing at optimal and suboptimal water temperature. Results in terms of growth in length and weight, conversion efficiency, dietary feed intake and utilization, body composition (whole fish and liver) as well as enzyme and immunological activities are presented. Fish growth was significantly reduced by the inclusion of plant proteins, although further addition of fish protein hydrolysates improved the results. Daily feed intake was not affected by plant protein inclusion in the diets, although the group fed the highest inclusion level showed lower ingestion than the rest of the groups, probably as a consequence of a reduced dietary palatability. The decrease in water temperature during the second part of the experiment had a negative effect on feed intake and fish growth. Gross visceral morphology of meagre fed the experimental diets was not affected, but muscle weight was significantly reduced. Whole body and liver composition was not affected with plant protein inclusion. However, the inclusion of fish protein hydrolysates resulted in a significant increase in fat content, especially in liver cholesterol and steryl esters, with a parallel reduction in protein. Brush border enzymes were affected by plant protein inclusion as well as serum lysozyme that significantly increased in the fish fed the highest inclusion level. As a conclusion, up to 315 g kg^?1 plant protein (76.2% of total protein content) can be included in the diet for meagre without affecting growth or feed utilization. Higher inclusion levels can also be used if at least 5% fish protein hydrolysate is also included.  相似文献   

Optimization of phosphorus content in high plant protein practical diets for Senegalese sole (Solea senegalensis,Kaup 1858) juveniles: influence on growth performance and composition of whole body and vertebrae          下载免费PDF全文

E. Salas‐Leiton  J. Dias  P. Gavaia  A. Amoedo  L.M.P. Valente 《Aquaculture Nutrition》2017,23(1):18-29

Practical diets containing PP sources were elaborated. Increasing levels of di‐calcium phosphate were added to diets leading to five different dietary available P levels: 2.5, 3.2, 6.0, 6.5 and 8.0 g kg^?1 dry diet. The dietary treatments were tested in 13.5 g Senegalese sole juveniles throughout an 82‐day experimental period. Dietary P content had no effect on the productive parameters, while nutrient intake was also similar among dietary treatments, except P intake. Dry matter ADC ranged between 54.9% and 64.0%, and the highest P ADCs value (47.2 ± 0.7%) was achieved in fish fed AP6.0. Dietary phosphorus level significantly influenced body lipid and P compositions. Regression analysis performed on whole‐body P and ash contents fitted to quadratic models. Vertebral bone P content was low but increased significantly with increasing dietary P levels. Bone density and deformities occurrence were, however, similar between experimental conditions. An altered status of bone formation–resorption processes in soles fed the lowest P content diet might be inferred from ALP and TRAP activities. In conclusion, overall results state a high tolerance of Senegalese sole to low P content diets and support the utilization of practical diets with high plant protein content.  相似文献   

Illegal and unreported fishing on abalone—Quantifying the extent using a fully integrated assessment model     

Éva Plagányi  Doug Butterworth  Markus Burgener 《Fisheries Research》2011,107(1-3):221-232

Illegal, unregulated and unreported (IUU) fishing is a major problem in many of the world's fisheries. The stocks most severely impacted centre on those characterised by high economic value, such as abalone, as well as long lived and slow growing species such as Patagonian toothfish (Dissostichus eleginoides). Effective management of these stocks as well as assessment of the impacts of IUU fishing on the resources is impeded by the technical difficulties associated with determining the magnitude of the IUU catches. The South African abalone Haliotis midae fishery rates as an extreme example of extraordinarily high levels of illegal and unreported (IU) catch. To assess the level and trends in IU catches, we used a combination of approaches that included collation of confiscation records from law enforcement, development of a novel index (the confiscations per unit policing effort—CPUPE), estimation of illegal catches using a spatial and age-structured assessment model, and cross-checking of model outputs through comparison with trade data on abalone imports in destination countries. The model-predicted 2008 IU estimate was 860 tonnes, more than 10 times the total allowable catch (TAC) for that year, and implied that, on average, 14% of all IU catches are confiscated. Associated management responses included the listing of H. midae on Appendix III of CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora), and a temporary closure of the commercial fishery. We summarise both technical and management lessons to be learnt from this integrated approach to assess and verify the magnitude of IU fishing.  相似文献   

Epilithic biofilm as a key factor for small‐scale river fisheries on Caribbean islands     

E. LEFRANÇOIS  S. COAT  G. LEPOINT  N. VACHIÉRY  O. GROS  D. MONTI 《Fisheries Management and Ecology》2011,18(3):211-220

Abstract Numerous freshwater species are consumed or exploited through artisanal fisheries in the rivers of the islands of Guadeloupe, French West Indies. Autochthonous production of organic matter is limited in these flowing rivers and is mainly represented by scarce filamentous green algae and an abundant epilithic biofilm growing on wet stones in the river bed. Stable isotope analysis was used to quantify the relative importance of biofilm and other riverine allochthonous and autochthonous food sources in the diet of tropical shrimps (Palaemonidae, Atyidae and Xiphocarididae) and fishes (Gobiidae and Eleotridae) consumed by the local people. The epilithic biofilm was exploited by most species, constituted an important source of autochthonous carbon and was an important source of organic matter production at the base of freshwater food webs in Caribbean rivers. Biofilm percentages in the diet reached 32% for molluscs, 85% for atyid shrimps, 29% for xiphocaridid shrimps, 14% for palaemonid shrimps and 13% for fish. Assessment of biofilm in nine rivers showed that blue and red cyanobacteria were quantitatively dominant with a moderately rich diatom flora. These results address the interactions between river biofilm and Caribbean freshwater fauna where trophic links between consumers and their potential resources have poorly been documented.  相似文献   

Effects of biofloc technology on reproduction and ovarian recrudescence in Nile tilapia          下载免费PDF全文

Érika Ramos de Alvarenga  Suellen Cristina Moreira de Sales  Túlio Soares de Brito  Cláudia Regina Santos  Rebeca Dias Serafim Corrêa  Gabriel Francisco de Oliveira Alves  Ludson Guimarães Manduca  Eduardo Maldonado Turra 《Aquaculture Research》2017,48(12):5965-5972

The objectives of this study were to evaluate the reproductive cycle, morphological changes of ovary and mobilization of energy reserves in Nile tilapia reared with biofloc technology (BFT). In general, the growth and reproductive performance were highly similar between BFT and Control system (clear water). Difference between the systems was found in the hepatosomatic index (using mixed‐effects models), which suggested that BFT can alter the energy mobilization in the post‐spawning period. The absolute and relative fecundity, fertilization rate, number of larvae produced per female, gonadosomatic index, proportion of oogenesis cells, number of post‐ovulatory and atretic follicles were similar between the two systems. We also did not detect a reduction in the reproductive cycle length in Nile tilapia reared in BFT. Because there was no evidence of the negative effects of BFT on Nile tilapia reproduction, we concluded that BFT might be used for breeder stocking of this species.  相似文献