Swimming performance,whole body ions,and gill Al accumulation during acclimation to sublethal aluminium in juvenile rainbow trout (Oncorhynchus mykiss)     

Rod W. Wilson  Chris M. Wood 《Fish physiology and biochemistry》1992,10(2):149-159

Juvenile rainbow trout (2–5 g) were chronically exposed (for 22 days) to acidified softwater (Ca²⁺ = 25 Eq/l, pH 5.2) in the presence or absence sublethal Al (30 g/l). Al-exposed fish (5.2/Al group) suffered 20% whole body Na⁺ and Cl^– losses and a 30% reduction in the maximum sustainable swimming speed (U_crit) over the initial 7 days. These disturbances were approximately 2 fold greater than those observed in the fish exposed to low pH alone (5.2/0 group). However, whole body ion levels were completely restored in the 5.2/Al fish by day 22, whereas they merely stabilized at a new reduced level in the 5.2/0 group. Increased resistance to acutely lethal Al (200 g/l at pH 5.2) was observed from day 17 onwards in the 5.2/Al fish. Despite this acclimation and recovery of whole body ions, U_crit remained significantly lower than in the 5.2/0 group throughout. Growth on a restricted diet of 1% body wt. /day was normal in the 5.2/0 group compared with controls maintained in pH 6.5 softwater, whereas 5.2/Al fish suffered a 50% reduction in growth rate on the same diet. The 5.2/Al fish accumulated large amounts of Al on the gills, reaching an initial peak after 4 days, followed by a decline at 7 days, and a secondary rise thereafter. Therefore acclimation and recovery of whole body ionic status was not associated with a reduction in the gill Al burden. Some of the metabolic costs of acclimation to Al, namely a continued impairment of swimming speed and growth, are discussed in light of the physiological and structural changes reported to occur at the gills.  相似文献   

Optimization of triploidy induction in the blacklip abalone, Haliotis rubra (Leach, 1814), using 6-dimethylaminopurine     

Wenshan Liu  Michael Heasman  & Rod Simpson 《Aquaculture Research》2004,35(11):1076-1085

Optimal conditions of 6‐dimethylaminopurine (6‐DMAP) for triploidy induction in the blacklip abalone Haliotis rubra (Leach, 1814) were investigated, targeting inhibition of second polar body (PB2) formation. Two experiments were conducted at a water temperature of 17.5–18.5°C where factorial combination of (1) four dosages (DSs) of 100, 150, 200 and 250 μM 6‐DMAP, four starting times (STs) of 15, 20, 25 and 30 min post fertilization, and two treatment durations (TDs) of 20 and 30 min and (2) three DSs of 50, 100 and 150 μM 6‐DMAP, three STs of 15, 20 and 25 min post fertilization, and three TDs of 10, 20 and 30 min, were applied respectively. Day 3 larvae were sampled for triploidy and survival. Percent triploidy was verified using flow cytometry (FCM). Results show that optimal inductions that combine both high rates of triploidy and reasonable survival were those treatments commenced 15 or 20 min post fertilization and continued for 20 or 30 min, using 100 μM 6‐DMAP. These conditions induced rates of triploidy and relative survival of 80.5–93.3% and 36.5–40.2%, respectively, in the first experiment, and corresponding rates were 79.1–93.6% and 20.7–43.0% in the second experiment. High percent triploidy were also obtained in a number of treatments using 150 μM 6‐DMAP, but with overall survival rates generally lower than those using 100 μM 6‐DMAP.  相似文献   

A comparison of Japanese and Australian consumers’ sensory perceptions of beef     

Rod J. Polkinghorne  Takanori Nishimura  Kate E. Neath  Ray Watson 《Animal Science Journal》2014,85(1):69-74

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The slow rise of technology: Computer vision techniques in fish population connectivity     

Sebastian Lopez-Marcano  Christopher J. Brown  Michael Sievers  Rod M. Connolly 《水产资源保护:海洋与淡水生态系统》2021,31(1):210-217

1. Technological advancements in data collection and analysis are producing a new generation of ecological data. Among these, computer vision (CV) has received increased attention for its robust capabilities for rapidly processing large volumes of digital imagery.
2. In marine ecosystems, the study of fish connectivity provides fundamental information for assessing fisheries stocks, designing and implementing protected areas and understanding the impact of habitat loss. While the field of fish connectivity has benefited from technological advancements, the extent to which novel techniques, such as CV, have been utilized has not been assessed. To inform future directions and developments, this study reviewed the current use of CV in fish connectivity research, quantified how the implementation of such technology in fish connectivity research compared with other areas of marine research and described how this field could benefit from CV.
3. The review found that the use of remote camera systems in fish connectivity research is increasing, but the implementation of automated analysis of digital imagery has been slow. Successful implementation and expansion of CV frameworks in aquaculture and coral reef ecology suggest that CV techniques could greatly benefit fish connectivity research.
4. A case study of potential use of CV in fish connectivity research, scaling up optimal foraging models to predict marine population connectivity, highlights how beneficial it could be.
5. The capacity for CV techniques to be adopted alongside traditional approaches, the unparalleled speed, accuracy and reliability of these approaches and the benefits of being able to study ecosystems along multiple spatial–temporal scales, all make CV a valuable tool for assessing connectivity. Ultimately, these technologies can assist data-driven decisions that directly influence the health and productivity of marine ecosystems.

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Testing the utility of abiotic surrogates for marine habitat mapping at scales relevant to management     

Tim Stevens  Rod M. Connolly 《Biological conservation》2004,119(3):351-362

Habitat mapping at the scale at which marine protected areas are designed and managed is essential for assessment of, and design for, representation. Most habitat mapping studies rely solely or in part on abiotic surrogates for patterns of biodiversity. The utility of abiotic variables in predicting biological distributions at the local scale (10 s of km) was tested in a remote video survey of macrobenthos in Moreton Bay, Australia. Habitat classifications of the same set of 41 sites based on 6 abiotic variables and abundances of 89 taxa and bioturbation indicators were compared using correlation, regression and ordination analyses. The concepts of false homogeneity (abiotically similar but biologically distinct) and false heterogeneity (abiotically distinct but biologically similar) were defined to describe types of errors associated with using abiotic surrogates to construct habitat maps, and quantified using two separate methods. Overall, the best prediction by abiotic surrogates explained less than 30% of the pattern of biological similarity. Errors of false homogeneity were between 20% and 62%, depending on the methods of estimation. Predictive capability of abiotic surrogates at the taxon level was poor, with only 6% of taxon/surrogate correlations significant. Abiotic variables did not discriminate sufficiently between different soft bottom communities to be a reliable basis for mapping. These results have implications for the widespread use of abiotic surrogates in marine habitat mapping to plan for, or assess, representation in marine protected areas. Little confidence can be placed in marine habitat classifications based solely or largely on abiotic surrogates without calibration by rigorous biological surveys at the appropriate scale. Therefore, it is questionable whether marine protected areas designed on this basis can have measurable benefits for conservation.  相似文献   

Identification of QTLs for phenolic compounds in oilseed rape (<Emphasis Type="Italic">Brassica napus L.</Emphasis>) by association mapping using SSR markers     

Abbas Rezaeizad  Benjamin Wittkop  Rod Snowdon  Maen Hasan  Valiollah Mohammadi  Abbas Zali  Wolfgang Friedt 《Euphytica》2011,177(3):335-342

Association mapping identifies quantitative trait loci (QTLs) by examining the marker-trait associations that can be attributed to the strength of linkage disequilibrium between markers and functional polymorphisms across a set of diverse germplasm. In this study, association mapping was performed to detect QTL-linked and genome wide SSR markers linked to phenolic compounds of extraction meal in a population of 49 genetically diverse oilseed rape cultivars of dark-seeded, winter-type oilseed rape accessions. Correction for population structure was performed using 559 genome wide SSR markers. Results showed that seed colour is an important contributor to seed meal quality. Totally, 52 SSR markers linked to phenolic compounds were detected, five of them being QTL linked markers. Some of these markers were already mapped on Brassica napus chromosomes that contain known QTL controlling oilseed rape meal quality traits. Our results demonstrate that association mapping is a useful approach to complement and enhance previous QTL information for marker-assisted selection.  相似文献   

A new basis for recognizing the paleocene/eocene boundary in Western interior north america     

Wing SL 《Science (New York, N.Y.)》1984,226(4673):439-441

Fossil pollen grains from Paleocene-Eocene rocks of the Bighorn Basin of Wyoming allow important sequences of terrestrial vertebrate fossils to be correlated with standard marine microfossil zonations. The Paleocene/Eocene boundary as based on pollen evidence falls within the Wasatchian land mammal age, much higher than the boundary used by some fossil mammal workers. This discrepancy partly results from multiple definitions of the Paleocene/Eocene boundary but may also indicate faulty mammal-based correlations to the type Sparnacian of France.  相似文献   

Oxidative bioactivation of S-alkyl phosphorothiolate pesticides: stereospecificity of profenofos insecticide activation   总被引：1，自引：0，他引：1  

K D Wing  A H Glickman  J E Casida 《Science (New York, N.Y.)》1983,219(4580):63-65

The mouse liver microsomal mixed-function oxidase system converts several phosphorothiolate pesticides with S-ethyl, S-propyl, or S-butyl groups to more potent inhibitors of acetylcholinesterase. This activation is stereospecific for the chiral isomers of O-(4-bromo-2-chlorophenyl) O-ethyl S-propyl phosphorothiolate (profenofos insecticide); the more toxic (-) isomer becomes a 34-fold better inhibitor of acetylcholinesterase in vitro, whereas the less toxic (+) isomer is deactivated by a factor of 2. Prior treatment of the microsomes with piperonyl butoxide or another mixed-function oxidase inhibitor markedly decreases the activation. Piperonyl butoxide also protects against brain acetylcholinesterase inhibition and cholinergic symptoms in chicks resulting from (-)-profenofos administration, thus establishing the importance of the oxidative bioactivation of S-alkyl phosphorothiolate pesticides in vivo.  相似文献   

The chemistry of sexual deception in an orchid-wasp pollination system     

Schiestl FP  Peakall R  Mant JG  Ibarra F  Schulz C  Franke S  Francke W 《Science (New York, N.Y.)》2003,302(5644):437-438

The "sexually deceptive" orchid Chiloglottis trapeziformis attracts males of its pollinator species, the thynnine wasp Neozeleboria cryptoides, by emitting a unique volatile compound, 2-ethyl-5-propylcyclohexan-1,3-dione, which is also produced by female wasps as a male-attracting sex pheromone.  相似文献   

RH 5849, a Nonsteroidal Ecdysone Agonist: Effects on Larval Lepidoptera     

Wing KD  Slawecki RA  Carlson GR 《Science (New York, N.Y.)》1988,241(4864):470-472

The ecdysone agonist RH 5849 (1,2-dibenzoyl-1-tert-butylhydrazine) causes the premature initiation of molting at all stages of larval development of the tobacco hornworm, Manduca sexta. This phenomenon occurs without an increase in the endogenous ecdysone (20-hydroxyecdysone) titers. RH 5849 likewise provokes the initiation of molting in larval abdomens in the absence of a source of endogenous hormone. Although substantially less active than 20-hydroxyecdysone in vitro, RH 5849 was 30 to >670 times as active as the authentic molting hormone in bioassays with isolated larval abdomens or intact hornworms. This reversal in potency can be attributed to the superior transport properties and metabolic stability of RH 5849 relative to 20-hydroxyecdysone. Thus RH 5849 and its analogs are relatively persistent ecdysone agonists that halt feeding in larval lepidoptera by forcing an ultimately lethal, developmentally premature molt.  相似文献