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S. GARCÍA P. DOMINGUES J.C. NAVARRO I. HACHERO D. GARRIDO C. ROSAS 《Aquaculture Nutrition》2011,17(2):e174-e187
Effects of two binders (gelatine and alginate) were tested on growth, survival, partial energy balance and lipid composition of mantle and digestive gland (DG) of Octopus vulgaris. The three diets tested were given as follows: CON, (Loligo gahi) as control, GEL, composed of squid paste (L. gahi) (300 g kg?1), fish hydrolyse CPSP® (100 g kg?1) and fish meal (500 g kg?1), agglutinated with 100 g kg?1 of gelatine and ALG, composed of squid paste (L. gahi) (300 g kg?1), fish hydrolyse CPSP® (100 g kg?1) and fish meal (500 g kg?1), all agglutinated with 100 g kg?1 of alginate. Growth rates were 13.7 ± 2.1, 2.1 ± 2.8 and ?2.4 ± 2.9 g kg?1 bw day?1, for octopuses fed CON, GEL and ALG diets, respectively. DGs of octopuses had higher concentrations of fatty acids (FA) than the mantle. DG of animals fed CON had higher concentrations of FAs than those fed the artificial diets. Energetic balance demonstrated that physiologically useful energy for maintenance E(B) was affected by type of diet, with negative values of E(B) in animals fed ALG and positive (85 and 154 kJ kg?1 day?1) in octopuses fed GEL and CON, respectively. The ALG diet did not cope with the physiological requirements for octopus growth. 相似文献
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GLORIA PARRA‐REQUENA FRANCESC XAVIER MOLINA‐MORALES PEDRO MANUEL GARCÍA‐VILLAVERDE 《Growth and change》2010,41(1):59-84
This paper analyzes the role played by the cognitive dimension of social capital on knowledge acquisition in clustered firms. We have applied a structural model to an empirical survey of the Spanish footwear industry. Findings detect a significant indirect effect of the district membership on knowledge acquisition through cognitive social capital development. In contrast with the assumption of direct and free access to common knowledge in territorial agglomerations, findings suggested that knowledge access depends on the capacity of the firms to share visions, goals, values, and culture with other actors in the local neighborhood. The social capital perspective provides a solid base to explain heterogeneity among firm members in the industrial district in order to access common knowledge and capacities. Findings suggested that institutions involved in a district must favour efforts to boost the collective representation as well as common goals and vision. 相似文献
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G. MANSO‐DÍAZ M. I. GARCÍA‐REAL C. CASTELEYN F. SAN‐ROMÁN O. TAEYMANS 《Equine veterinary journal》2013,45(2):187-192
Reasons for performing study: Noncontrast magnetic resonance angiography (MRA) is widely used in human and small animal medicine. However, this technique has not yet been described in the horse, and compared to other angiographic techniques MRA could be more cost efficient and potentially safer. Objectives: The aim of this study was to provide a comprehensive anatomical reference of the normal equine head vasculature using a noncontrast MRA technique, on both low‐ and high‐field MRI. Methods: Five healthy adult horses were examined, 4 with a low‐field magnet (0.23T) and the remaining one with a high‐field magnet (1.5T). The magnetic resonance angiography sequence used was TOF (time‐of‐flight) 2D‐MRA and CT images of a vascular corrosion cast were subsequently used as anatomical references. Results: The MRA imaging protocol provided good visualisation of all major intra‐ and extracranial vessels down to a size of approximately 2 mm in diameter on both low‐ and high‐field systems. This resulted in identification of vessels to the order of 3rd–4th branches of ramification. The visibility of the arteries was higher than of the veins, which showed lower signal intensity. Overall, MRA obtained with the high‐field protocol provided better visualisation of the arteries, showing all the small arterial branches with a superior resolution. Conclusions: The use of a specific vascular sequence such as TOF 2D‐MRA allows good visualisation of the equine head vasculature and eliminates the need for contrast media for MRA. Potential relevance: Magnetic resonance angiography allows for visualisation of the vasculature of the equine head. Vessel morphology, symmetry and size can be evaluated and this may possibly play a role in preoperative planning or characterisation of diseases of the head, such as neoplasia or guttural pouch mycosis. 相似文献
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An optimized high quality male DNA extraction from spermatophores in open thelycum shrimp species
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Laia PLANELLA Sandra HERAS Manuel VERA José‐Luis GARCÍA‐MARÍN María Inés ROLDÁN 《Integrative zoology》2017,12(5):421-427
The crucial step of most of the current genetic studies is the extraction of DNA of sufficient quantity and quality. Several genomic DNA isolation methods have been described to successfully obtain male DNA from shrimp species. However, all current protocols require invasive handling methods with males for DNA isolation. Using Aristeus antennatus as a model we tested a reliable non‐invasive differential DNA extraction method to male DNA isolation from spermatophores attached to female thelycum. The present protocol provides high quality and quantity DNA for polymerase chain reaction amplification and male genotyping. This new approach could be useful to experimental shrimp culture to select sires with relevant genetic patterns for selective breeding programs. More importantly, it can be applied to identify the mating pairs and male structure in wild populations of species as A. antennatus, where males are often difficult to capture. Our method could be also valuable for biological studies on other spermatophore‐using species, such as myriapods, arachnids and insects. 相似文献
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E.E. RUFINO‐PALOMARES F.J. REYES‐ZURITA L. GARCÍA‐SALGUERO J. PERAGÓN M. DE LA HIGUERA J.A. LUPIÁÑEZ 《Aquaculture Nutrition》2012,18(2):138-151
Maslinic acid (MA) is a natural triterpene that can be used as an additive in the diet of trout. We investigated the effects of feeding with MA and a fixed ration (10 g kg?1 body weight) with respect to growth, protein‐turnover rates and nucleic‐acid concentration in the liver of gilthead sea bream grown under fish‐farm conditions. Five groups of 12 g of a mean body mass were fed for 210 days with diets containing 0 (control), 0.05 and 0.1 g of MA per kg of diet. Two groups were fed ad libitum (control AL and MA100AL), and three with a fixed ration (control R, MA50R and MA100R). At the end of the experiment, higher body weights, liver weight, feed‐efficiency and PER were found in MA100AL and MA100R fish. Fractional and absolute protein‐synthesis rates in liver of MA100R fish were higher than in the control, resulting in a higher absolute protein‐accumulation rate and tissue growth. Total DNA content in MA100AL and MA100R was higher than in control. Studies of light and electron microscopy corroborated these results. These findings indicate that MA added to the diet can stimulate growth, hepatic protein‐turnover rates and tissue hyperplasia in gilthead sea bream. 相似文献
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Francisco Alberto GARCíA-VáZQUEZ Iván HERNáNDEZ-CARAVACA Carmen MATáS Cristina SORIANO-úBEDA Silvia ABRIL-SáNCHEZ María José IZQUIERDO-RICO 《The Journal of reproduction and development》2015,61(5):407-413
Once deposited in the female tract, sperm face a series of challenges that must be overcome to ensure the presence of an adequate normal sperm population close to the site of fertilization. Our aim was to evaluate the influence of the uterine milieu on boar sperm morphology. In experiment 1, sperm morphology was evaluated in the backflow (60 min after insemination) and within the uterotubal junction (UTJ) (collected ~24 h after insemination) following intrauterine sperm deposition (n = 6) and compared with the morphology of the sperm in the insemination dose. In experiment 2, the influence of the uterine fluid (UF) on sperm morphological modifications was evaluated. For this purpose, ejaculated (n = 4) and epididymal (n = 4) sperm were in vitro incubated with or without UF for 2 and 24 h. In both experiments, sperm were classified as normal, having a cytoplasmic droplet (proximal or distal) or having tail defects. The results of experiment 1 pointed to an
increase in morphologically abnormal sperm collected in the backflow (27.70%) and a reduction of the same in the UTJ (2.12%) compared with the insemination dose (17.75%) (P < 0.05). In experiment 2, incubation of ejaculated sperm with UF did not provoke any morphological modifications; however, when epididymal sperm were incubated with UF, a pronounced increase in the percentage of normal sperm was evident after 24 h compared with the initial dose (from 25.77% to 53.58%, P < 0.05), mainly due to distal cytoplasmatic droplet shedding (53.22 vs. 20.20%). In conclusion, almost all the sperm that colonize the UTJ had a normal morphology, with part of the abnormal sperm having been discarded in the backflow and part selected/modified on their way to the oviduct. UF seems to influence cytoplasmic distal droplet removal, as demonstrated previously in seminal plasma. 相似文献
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S. GARCÍA‐GARRIDO I. HACHERO‐CRUZADO P. DOMINGUES N. LÓPEZ C. ROSAS 《Aquaculture Nutrition》2011,17(4):e825-e839
Effects of artificial diets were tested on growth and digestive gland (DG) lipid composition of juvenile Octopus vulgaris. For Experiment I, three diets were used: (i) SQUID (Loligo gahi) as a control diet; (ii) Squid paste and fish hydrolysate CPSP®, agglutinated with gelatine (GEL20); and (iii) Squid paste, fish hydrolysate CPSP® and gelatine (GEL40). For Experiment II, three diets were used: (i) SQUID, control diet; (ii) Squid paste, CPSP® and alginate (ALG10); and (iii) Squid paste, CPSP® and alginate (ALG20). For both experiments, growth rates for octopuses fed control were higher (P < 0.05), while artificial diets were not different (P > 0.05) between them. All diets promoted similar growth, regardless of the different CPSP® concentrations and binders. Growth rates obtained were among the highest obtained for O. vulgaris with artificial diets until now. The lower growth obtained with the artificial diets was greatly reflected in the DG fatty acid composition. The most important fatty acid groups, such as n‐3 highly unsaturated fatty acids, decreased in the DG of animals fed artificial diets. Lipid content, particularly neutral lipids, was higher in the DG of octopuses fed squid, indicating higher nutritional condition of these animals compared to those fed the artificial diets. 相似文献
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Hybridisation between wheat and Aegilops geniculata was quantified in a 4‐year crossing experiment in the glasshouse, using three wheat cultivars as pollen donors and herbicide resistance as a phenotypic marker. Hybridisation rates ranged from 5% to 74%. Most of the hybrids were self‐sterile. However, seven F2 seeds were obtained from 165 A. geniculata–wheat hybrids. Hybrid seeds were found in all backcross (BC1) combinations at average rates of 4.2% (0–26.3%) and 5.88% (0–34%) under glasshouse and field experiments, respectively, with significant differences among years and cultivars. Wheat cultivars, F1 and BC1 plants, were resistant to herbicides while A. geniculata plants were susceptible. In the subsequent generations, although few plants were available, the BC1F1 had a certain degree of fertility and the fertility increased in the F2 plants, with one plant that reached 66.7%. The commercial growing of genetically modified herbicide‐tolerant wheat is expected to have the potential for the inserted gene to escape from the crop and become incorporated in a closely related wild species, conferring a competitive advantage to these conferring weeds. Determining the frequency of crop‐wild transgene flow and the fertility of the formed hybrids is a necessity for risk assessment. Data presented here provide new knowledge on the potential A. geniculata–wheat herbicide resistance transfer. 相似文献