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The characterization of sperm motility patterns, particularly post‐activation changes, is the first step in setting up species‐specific protocols involving gamete management and embryo production, for both aquaculture and laboratory research purposes. This study is aimed at the characterization of the sperm motility pattern of the purple sea urchin Paracentrotus lividus. Semen samples were individually diluted in artificial sea water for sperm motility activation. They were then incubated at 18°C for up to 24 hr. Motility was evaluated on dilution, and 1 hr, 3 hr and 24 hr after activation, by computerized analyser. The semen fertilization capacity was also evaluated. Under our experimental conditions (dilution 1:1,000 in artificial sea water plus 0.05% BSA, 18°C, in the dark), P. lividus semen remained viable for up to 24 hr, as the total motile sperm and the fertilization percentages did not change significantly during the incubation time. In contrast, the mean curvilinear velocity and the subpopulation of rapid sperm (those having a curvilinear velocity > 100 µm/s) slightly but significantly decreased after 3 hr, thereafter remaining unchanged for up to 24 hr after activation. In conclusion, our results show that diluted P. lividus semen can be used for a longer period than that of most fish species, with no need for motility inhibition procedures, supporting its wider use in laboratory research. In addition, the development of artificial fertilization protocols for aquaculture production is simplified by long‐lasting sperm motility. 相似文献
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Stefano Carbonara Raffaele D'Adamo Andrea Novelli Sergio Pelosi Adele Fabbrocini 《Aquaculture Research》2019,50(9):2469-2476
The development of sustainable methods for sea urchin juvenile production is currently constrained by high mortality rates during larval growth and the high costs of larval rearing systems management. With the aim of developing a method for the production of juveniles of the purple sea urchin Paracentrotus lividus in a medium‐scale recirculating system, the present study focused on the effects of high stocking densities on larval growth. Plutei larvae were reared at three different densities (up to 7 ind/ml) in a semi‐static culture system. Larval survival and metamorphosis success were evaluated in order to identify the most effective density range. The highest metamorphosis rates (80%–95%) were obtained at 4 and 7 larvae/ml. These results are comparable with (and in some cases higher than) those reported for the same species at much lower larval densities. In conclusion, the rearing conditions tested here show for the first time that a significantly higher (4 ind/ml) stocking density than those of traditional P. lividus rearing methods (based on large volumes and low densities) can be adopted, thus supporting the feasibility of an increase in the final output of competent larvae with no increase in rearing volumes. 相似文献
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Chiara Nobili Simone D’Angeli Maria Maddalena Altamura Valeria Scala Anna Adele Fabbri Massimo Reverberi Corrado Fanelli 《European journal of plant pathology / European Foundation for Plant Pathology》2014,139(2):423-438
Wheat germinating caryopses may represent a starting point for the Fusarium Head Blight disease; however, only few studies concern the defence repertoire of wheat caryopses against fungal challenge. The germinating caryopses of two wheat commercial varieties (Blasco and Sagittario), differentially susceptible to FHB in the field, were inoculated with F. graminearum and the redox status in the interaction milieu, oxylipin production, the expression profile of some host-defence related genes, and programmed cell death in the aleuronic layer, were analysed. In Sagittario, the redox balance was profoundly modified and 9-oxylipins accumulated during fungal contamination. In this variety, F. graminearum produced a high quantity of deoxynivalenol whilst programmed cell death, also through metacaspases activation, was enhanced in the aleuronic layer of its caryopses. In Blasco, the expression of tolerance factors such as Pathogenesis-Related-protein1, glucosyl-transferase and glutathione transferase genes was up-regulated consequent to infection. Results show that unscavenged ROS and 9-oxylipins may be related to deoxynivalenol accumulation in the germinating caryopses of wheat after F. graminearum infection. 相似文献
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Marco Zampiga Luca Laghi Massimiliano Petracci Chenglin Zhu Adele Meluzzi Sami Dridi Federico Sirri 《畜牧与生物技术杂志(英文版)》2019,(1)
Background: Due to the important functions of arginine in poultry,it should be questioned whether the currently adopted dietary Arg:Lys ratios are sufficient to meet the modern broiler requirement in arginine.The present study aimed,therefore,to evaluate the effects of the dietary supplementation of L-arginine in a commercial broiler diet on productive performance,breast meat quality attributes,incidence and severity of breast muscle myopathies and foot pad dermatitis(FPD),and plasma and muscle metabolomics profile in fast-growing broilers.Results: A total of 1,170 1-day-old Ross 308 male chicks was divided into two experimental groups of 9 replicates each fed either a commercial basal diet(CON,digestible Arg:Lys ratio of 1.05,1.05,1.06 and 1.07 in each feeding phase,respectively) or the same basal diet supplemented on-top with crystalline L-arginine(ARG,digestible Arg:Lys ratio of 1.15,1.15,1.16 and 1.17,respectively).Productive parameters were determined at the end of each feeding phase(12,22,33,43 d).At slaughter(43 d),incidence and severity of FPD and breast myopathies were assessed,while plasma and breast muscle samples were collected and analyzed by proton nuclear magnetic resonancespectroscopy.The dietary supplementation of arginine significantly reduced cumulative feed conversion ratio compared to the control diet at 12 d(1.352 vs.1.401,P 0.05),22 d(1.398 vs.1.420; P 0.01) and 33 d(1.494 vs.1.524; P 0.05),and also tended to improve it in the overall period of trial(1.646 vs.1.675; P = 0.09).Body weight was significantly increased in ARG compared to CON group at 33 d(1,884 vs.1,829 g; P 0.05).No significant effect was observed on meat quality attributes,breast myopathies and FPD occurrence.ARG birds showed significantly higher plasma concentration of arginine and leucine,and lower of acetoacetate,glutamate,adenosine and proline.Arginine and acetate concentrations were higher,whereas acetone and inosine levels were lower in the breast of ARG birds(P 0.05).Conclusions: Taken together,these data showed that increased digestible Arg:Lys ratio had positive effects on feed efficiency in broiler chickens probably via modulation of metabolites that play key roles in energy and protein metabolism. 相似文献
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An 8-year-old neutered female British Blue cat was presented with a presumed diagnosis of a prolapsed nictitans gland and associated ocular irritation and epiphora. However, during surgery, the apparent nictitans gland protrusion was determined to be an everted cartilage of the nictitating membrane. The scrolled portion of the cartilage was removed through an incision through the conjunctiva on the bulbar aspect of the third eyelid, as previously described in the dog. This operation resolved the ocular irritation occurring, and the third eyelid returned to its anatomically correct position. 相似文献
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Influence of maternal habitat choice,environment and spatial distribution of juveniles on their propensity for anadromy in a partially anadromous population of rainbow trout (Oncorhynchus mykiss) 
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下载免费PDF全文 Ana Laura Liberoff Analia Pamela Quiroga Carla Marcela Riva‐Rossi Jessica Adele Miller Miguel Alberto Pascual 《Ecology of Freshwater Fish》2015,24(3):424-434
This study evaluated the importance of the environment and spatial distribution of juvenile fish for the adoption of alternative migratory tactics in a partially anadromous population of rainbow trout (Oncorhynchus mykiss) from the Santa Cruz River. We captured young‐of‐the‐year fish along the river during autumn 2009, 2010 and spring 2010 and determined their maternal origin (anadromous vs. resident) using strontium to calcium ratios in the otolith core. Relative proportion of anadromous offspring, modelled with logistic regression, increased towards headwaters and in areas with deeper channels and larger substrate composition. Body length, modelled with linear multiple regression, varied positively with site depth, water velocity, substrate size and anadromous maternal origin. Based on evidence for limited juvenile movements (<25 km), the spatial extent of this study (240 Rkm) and the identification of large, contrasting reaches along the river, it is likely that the observed spatial distribution of juveniles and their association to sites with coarse substrate composition reflects maternal spawning activity. Results further indicate that anadromous females breed predominantly in middle and upper river sections in areas with coarse substrate. Given that body size in this system has been positively related to propensity for anadromy, we propose that female spawning choice affects their offspring's spatial distribution, providing the adequate physical template for anadromous offspring to reach or maintain larger body sizes and display anadromy themselves. Relevance of this study is also discussed in the context of alterations in response to future dam construction in one of the latest free‐flowing rivers sustaining anadromous O. mykiss. 相似文献
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Saiardi A Bhandari R Resnick AC Snowman AM Snyder SH 《Science (New York, N.Y.)》2004,306(5704):2101-2105
The inositol pyrophosphates IP7 and IP8 contain highly energetic pyrophosphate bonds. Although implicated in various biologic functions, their molecular sites of action have not been clarified. Using radiolabeled IP7, we detected phosphorylation of multiple eukaryotic proteins. We also observed phosphorylation of endogenous proteins by endogenous IP7 in yeast. Phosphorylation by IP7 is nonenzymatic and may represent a novel intracellular signaling mechanism. 相似文献
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Alkyl nitrates are a significant component of the "odd nitrogen" reservoir and play an important role in regulating tropospheric ozone levels in remote marine regions. Measurements of methyl and ethyl nitrate in seawater and air samples along two Atlantic Ocean transects provide the first direct evidence for an oceanic source of these compounds. Equatorial surface waters were highly supersaturated (up to 800%) in both species, with the waters in the temperate regions generally being closer to equilibrium. A simple box model calculation suggests that the equatorial source could be a major component of the local atmospheric alkyl nitrate budget. 相似文献
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Interventions shown to aid executive function development in children 4 to 12 years old 总被引：1，自引：0，他引：1
To be successful takes creativity, flexibility, self-control, and discipline. Central to all those are executive functions, including mentally playing with ideas, giving a considered rather than an impulsive response, and staying focused. Diverse activities have been shown to improve children's executive functions: computerized training, noncomputerized games, aerobics, martial arts, yoga, mindfulness, and school curricula. All successful programs involve repeated practice and progressively increase the challenge to executive functions. Children with worse executive functions benefit most from these activities; thus, early executive-function training may avert widening achievement gaps later. To improve executive functions, focusing narrowly on them may not be as effective as also addressing emotional and social development (as do curricula that improve executive functions) and physical development (shown by positive effects of aerobics, martial arts, and yoga). 相似文献