Relationships between individual movement,trophic position and growth of juvenile pike (Esox lucius)          下载免费PDF全文

Marina J. Nyqvist  Julien Cucherousset  Rodolphe E. Gozlan  J. Robert Britton 《Ecology of Freshwater Fish》2018,27(1):398-407

Variation in movement between individuals can have important ecological effects on populations and ecosystems, yet the factors driving differences in movement and their consequences remain poorly understood. Here, individual variability in the movements of juvenile (age 0 +  and 1 +  year) pike Esox lucius was assessed using passive integrated transponder (PIT) telemetry in off‐channel nursery areas over a 26‐ month period. Differences in the movement patterns of individuals were tested against their body sizes, ages, growth rates and trophic positions using data collected through a combination of catch‐and‐release sampling and stable isotope analyses. Results revealed that variation in movement between individuals was affected by age, with 1 +  individuals moving more than individuals of age 0 + , but not length. Individuals whose TP was low on their initial capture event moved significantly less than those with a higher initial TP. Individuals that moved more grew faster and achieved a higher final TP. These results suggest that higher activity (i.e., increased movement) increases resource acquisition that enhances growth rates, which could ultimately maximise individual performances.  相似文献   

Early life history connectivity of Antarctic silverfish (Pleuragramma antarctica) in the Ross Sea          下载免费PDF全文

Cassandra M. Brooks  Jilda Alicia Caccavo  Julian Ashford  Robert Dunbar  Kimberly Goetz  Mario La Mesa  Lorenzo Zane 《Fisheries Oceanography》2018,27(3):274-287

A recent population hypothesis for Antarctic silverfish (Pleuragramma antarctica), a critical forage species, argued that interactions between life history and circulation associated with glacial trough systems drive circumpolar distributions over the continental shelf. In the Ross Sea, aggregations of eggs and larvae occur under fast ice in Terra Nova Bay, and the hypothesis predicted that dispersing larvae encounter outflow along the western side of Drygalski Trough. The outflow advects larvae towards the shelf‐break, and mixing with trough inflow facilitates return toward the inner shelf. To examine the hypothesis, we compared samples of P. antarctica collected near Coulman Island in the outflow, along Crary Bank in the inflow, and a third set taken over the rest of the Ross Sea. We ruled out misidentification using an innovative genetic validation. Silverfish larvae comprised 99.5% of the catch, and the highest population densities were found in Drygalski Trough. The results provided no evidence to reject the population hypothesis. Abundance indices, back‐calculated hatching dates, length distributions and growth were congruent with a unified early life history in the western Ross Sea, constrained by cryopelagic early stages in Terra Nova Bay. By contrast, a sample in the Bay of Whales revealed much smaller larvae, suggesting either a geographically separate population in the eastern Ross Sea, or westward connectivity with larvae spawned nearby by fish sourced from troughs upstream in the Amundsen Sea. These results illustrate how hypotheses that integrate population structure with life history can provide precise spatial predictions for subsequent testing.  相似文献   

“Periderm Disorder Syndrome”: a New Name for the Syndrome Formerly Referred to as Pink Eye     

Edward C. Lulai  Robert P. Sabba  Philip Nolte  Neil C. Gudmestad  Gary A. Secor 《American Journal of Potato Research》2018,95(4):435-440

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Performance Behavior of Chitosan Based Water Dispersible Polyurethanes: Physicochemical Properties     

Noureen Arshad  Khalid Mahmood Zia  Farukh Jabeen  Muhammad Naveed Anjum  Nadia Akram  Muhammad Kaleem Khosa 《Fibers and Polymers》2018,19(11):2219-2228

The research work was carried out to synthesize a series of novel chitosan based water dispersible polyurethanes (CS-WDPUs). The three step synthesis involves the formation of end capped PU-prepolymer was formed through the reaction between polyethylene glycol (PEG) (Mn=600 g/mole, dimethylolpropionic acid (DMPA) and isophorone diisocyanate (IPDI) followed by the preparation of neutralized NCO terminated PU-prepolymer, which lead to the chain extension by using the chitosan. The dispersion of the obtained product was carried out by adding proper proportion of water. The synthesized CS-WDPUs were applied onto the different qualities of plain weave poly-cotton printed and dyed textile swatches by employing pad-dry-cure procedures. The textile assets of the treated and untreated textile swatches were assessed, as color fastness, pilling resistance, tear and tensile strength. The results showed that the chitosan incorporation into PU backbone has significant effect on the assets of treated textiles. These synthesized CS-WDPUs are eco-friendly bio-based finishes with potential applications for polyester/cotton textiles.  相似文献   

Native pollinator management may be a key to improving fruit set in Tasmanian Mountain Pepper,Tasmannia lanceolata (Winteraceae), an emerging spice resource     

Matthew D. Wilson  Adelina Latinovic  Noel W. Davies  Peter B. McQuillan  Robert C. Menary 《Journal of Crop Improvement》2018,32(3):331-352

Tasmanian Mountain Pepper is a new crop that produces a valuable flavoring agent derived from its fruit. However, annual yields are unpredictable and its commercial prospects depend upon a reliable fruit set. As poor pollination is a possible cause, the pollination biology of this dioecious plant was examined in natural and plantation settings using direct observations, sticky traps, gas chromatography, and microscopy. A community of small insects visits the flowers, and the insect species represent at least seven families of small flies, three families of beetles, and various wasps and moths. Pollen grains were observed on the bodies of bibionid flies (Bibionidae), syrphid flies (Syrphidae), and snail-flies (Sciomyzidae). The tetrahedral tetrad pollen grains are unlikely to be suitable for dispersal by wind. Similar volatiles were emitted by both males and females; several ocimene compounds are attractants for insect pollen vectors. The female flowers also emitted indole, a known fly attractant. It is therefore likely that Tasmannia lanceolata is dependent on the services of diverse insects, especially Diptera, for promoting fruit set. Plantations should be established in the vicinity of biodiverse native vegetation that supports a wide variety of native flying insects capable of transferring pollen.  相似文献   

Conservation Management Practices and Rotations for Irrigated Processing Potato in Southern Alberta     

Francis J. Larney  Drusilla C. Pearson  Robert E. Blackshaw  Newton Z. Lupwayi  Dermot R. Lynch 《American Journal of Potato Research》2016,93(1):50-63

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Grading Seed Potato Lots to Remove Tubers with Powdery Scab Damage may not Eliminate the Pathogen Threat     

Robert S. Tegg  Tamilarasan Thangavel  Mark A. Balendres  Calum R. Wilson 《American Journal of Potato Research》2016,93(3):231-238

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Identification of a Pro-Angiogenic Potential and Cellular Uptake Mechanism of a LMW Highly Sulfated Fraction of Fucoidan from Ascophyllum nodosum     

Nicolas Marinval  Pierre Saboural  Oualid Haddad  Murielle Maire  Kevin Bassand  Frederic Geinguenaud  Nadia Djaker  Khadija Ben Akrout  Marc Lamy de la Chapelle  Romain Robert  Olivier Oudar  Erwan Guyot  Christelle Laguillier-Morizot  Angela Sutton  Cedric Chauvierre  Frederic Chaubet  Nathalie Charnaux  Hanna Hlawaty 《Marine drugs》2016,14(10)

Herein we investigate the structure/function relationships of fucoidans from Ascophyllum nodosum to analyze their pro-angiogenic effect and cellular uptake in native and glycosaminoglycan-free (GAG-free) human endothelial cells (HUVECs). Fucoidans are marine sulfated polysaccharides, which act as glycosaminoglycans mimetics. We hypothesized that the size and sulfation rate of fucoidans influence their ability to induce pro-angiogenic processes independently of GAGs. We collected two fractions of fucoidans, Low and Medium Molecular Weight Fucoidan (LMWF and MMWF, respectively) by size exclusion chromatography and characterized their composition (sulfate, fucose and uronic acid) by colorimetric measurement and Raman and FT-IR spectroscopy. The high affinities of fractionated fucoidans to heparin binding proteins were confirmed by Surface Plasmon Resonance. We evidenced that LMWF has a higher pro-angiogenic (2D-angiogenesis on Matrigel) and pro-migratory (Boyden chamber) potential on HUVECs, compared to MMWF. Interestingly, in a GAG-free HUVECs model, LMWF kept a pro-angiogenic potential. Finally, to evaluate the association of LMWF-induced biological effects and its cellular uptake, we analyzed by confocal microscopy the GAGs involvement in the internalization of a fluorescent LMWF. The fluorescent LMWF was mainly internalized through HUVEC clathrin-dependent endocytosis in which GAGs were partially involved. In conclusion, a better characterization of the relationships between the fucoidan structure and its pro-angiogenic potential in GAG-free endothelial cells was required to identify an adapted fucoidan to enhance vascular repair in ischemia.  相似文献   

Recirculation nursery systems for bivalves     

Pauline Kamermans  Ainhoa Blanco  Sandra Joaquim  Domitília Matias  Thorolf Magnesen  Jean Louis Nicolas  Bruno Petton  Rene Robert 《Aquaculture International》2016,24(3):827-842

In order to increase production of bivalves in hatcheries and nurseries, the development of new technology and its integration into commercial bivalve hatcheries is important. Recirculation aquaculture systems (RASs) have several advantages: high densities of the species can be cultured resulting in a cost-effective production system; optimal temperature maximizes production and allows rapid turnover of the product; stable water quality improves growth rate and minimizes stress and potential loss by diseases. Pilot RAS systems were developed for seed rearing of oysters (Crassostrea gigas), scallops (Pecten maximus), mussels (Mytilus edulis) and clams (Ruditapes decussatus). Optimal feed addition and waste matrix were determined. Based on this, system flow rates were designed. Seed growth in the pilot RAS systems was compared at different renewal rates and with growth in flow-through systems (FTS). All four species can be reared in RAS and showed similar growth in RAS and in FTS or in RAS with a higher renewal rate. RAS can keep O₂, nitrogen and pH within the desired range. Temperature was generally higher in RAS than in FTS, probably due to heat induced by the pump circulating the water. The supply of sufficient amount of food in combination with a desire to reduce the renewal rate calls for use of concentrated feed in RAS.  相似文献   

<Superscript>1</Superscript>H-NMR metabolite profiling of abalone digestive gland in response to short-term starvation     

John R. Sheedy  Sébastien Lachambre  David K. Gardner  Robert W. Day 《Aquaculture International》2016,24(2):503-521

The effect of a short-term feeding and starvation experiment on juvenile abalone (Haliotis rubra × H. laevigata) was investigated (average length = 67 mm; average weight = 48 g). All aquaculture experiments were conducted at The University of Melbourne, Australia. Artificial feed was supplied ad libitum to the fed group, and no feed was supplied to the starved group. A modified metabolite extraction protocol using deuterated solvents was developed for ¹H-NMR-based metabolite profiling of digestive gland in response to the short-term feeding/starvation experiment, to avoid lyophilisation prior to biochemical analysis. PLS-DA revealed that fed and starved abalone are metabolically distinct from each other after 28 and 56 days. After 28 days, the fed group was defined by an increase in arginine, glucose, glutamate, glycine, inosine and uracil (P < 0.05), and the starved group was defined by an increase in N,N-dimethylglycine. After 56 days, the fed group still displayed increased glucose (P < 0.05), while N,N-dimethylglycine remained elevated in the starved group (P < 0.05). Arginine and glycogen were all higher at 28 days compared to 56 days, suggesting decreased anaerobic energy production at the later time point. Only glucose and N,N-dimethylglycine were significantly different between the fed and starved groups after 56 days, suggesting that abalone had not acclimatised to the starvation treatment after 28 days. These results infer N,N-dimethylglycine is a robust marker for short-term starvation in abalone. ¹H-NMR was also conducted on the artificial feed and starved abalone faecal matter, revealing the biochemical differences between them and digestive gland tissue. These methodology and results will facilitate a deeper understanding of the nutritional and physiological requirements of abalone in an aquaculture setting.  相似文献