Correlación Anatomo-radiológica de la Cabeza en la Cabra de Raza Canaria (Capra hircus L.)     

A. Arencibia  J. M. Vázquez  J. A. Ramirez-Gonzalez  F. Moreno  F. Gil  R. Latorre  G. Ramirez-Zarzosa  J. A. Sandoval  y C. Sosa-Perez   《Anatomia, histologia, embryologia》1997,26(3):165-172

A radiologic and tomographic study was made of the cranioencephalic topography of canary goats of medium weight and size. In a first step, the exocranialis references corresponding to an axis designed at the level of the meatus acusticus externus and parallel to the basicranial axis were anatomically and radiologically defined. Conventional stereotaxic techniques were then used to reach the standard position of the head in order to obtain macroscopical cross sections at different levels perpendicular to the base of the cranium. In a second step, a tomographic study was made to confirm the design of the axis.  相似文献   

Nitrogen loading of Eucalyptus globulus seedlings: nutritional dynamics and influence on morphology and root growth potential     

Acevedo  Manuel  Rubilar  Rafael  Dumroese  R. Kasten  Ovalle  Juan F.  Sandoval  Simón  Chassin-Trubert  Rodrigo 《New Forests》2021,52(1):31-46

New Forests - Achieving successful outplanting of trees on increasingly harsher sites is a global concern. In Chile, for example, new Eucalyptus globulus plantations are being targeted to poorer,...  相似文献   

Relation between lipid and fatty acid composition of eggs and larval survival in white pacific shrimp (Penaeus vannamei, Boone, 1931)     

Elena Palacios  Ilie S. Racotta  Horacio Heras  Yanic Marty  Jeanne Moal  Jean-François Samain 《Aquaculture International》2001,9(6):531-543

In this study, lipid classes and fatty acid composition were determinedin eggs of P. vannamei as a function of survival to zoeaIII stage. Spawns were reared individually to zoea III and grouped, accordingtotheir final survival to this larval stage, into spawns of high and lowsurvival.Eggs of individual spawns were analyzed for lipid and fatty acid composition ofneutral and polar lipids and the results were then grouped according tosurvivalto zoea III. The lipids within each group (high and low survival to zoea III)were pooled for the separation of phospholipids and the analysis of their fattyacid composition.Higher levels of triglycerides, carotenoids, and linoleic (18:2n-6) acid ineggs were associated with improved survival to zoea III. Linoleic acid washigher in spawns from the high survival group in both neutral and polarfractions and in most of the phospholipid classes analyzed. Docosahexanoic acid(DHA) was not related to survival to zoea, probably because its content washighenough (> 15% of total fatty acids) to satisfy embryo and early larvaldevelopment needs. A high content of eicosapentaenoic acid (EPA) was found inphosphatidylethanolamine, lysophosphatidylethanolamine, phosphatidylserine, andphosphatidylinositol compared to other phospholipid classes, suggesting aspecific role of EPA in these lipids. These results describe the specificphospholipid composition of penaeid eggs and could (potentially) be used aspredictive indicators of larval quality for research and production purposes.  相似文献   

Rearing fry of South American catfish (Rhamdia sapo) on natural zooplankton populations     

Horacio E. Zagarese 《Aquaculture (Amsterdam, Netherlands)》1988,70(4):323-331

Two experiments were performed on rearing South American catfish (Rhamdia sapo) fry in 8-m² concrete tanks. Live zooplankton was found to be an adequate food for Rhamdia fry. However, fry showed a natural preference for benthic organisms when they were available. No differences in selectivity due to fry age were observed. Differences in selectivity between small and large fry were only detected for Daphnia parvula, the largest zooplanktonic item. This suggested that food partitioning may occur only when large prey items are available.  相似文献   

The potential of temporary shelters to increase survival of the endangered Mexican axolotl     

Alejandra G. Ramos  Horacio Mena-González  Luis Zambrano 《水产资源保护:海洋与淡水生态系统》2021,31(6):1535-1542

1. Amphibian populations worldwide are in decline. Proactive conservation techniques such as translocations into created and restored wetlands have gained popularity in recent years but may fail owing to high predation and low environmental adaptability.
2. The Mexican axolotl (Ambystoma mexicanum), affected by rapid urbanization, is now possibly extinct in the wild despite millions living in captivity throughout the world.
3. The aim of this study was to explore whether ponds from an artificial wetland can function as temporary shelters for a viable population of axolotls that could be re-introduced into their native ecosystem in Xochimilco once it is restored.
4. Egg-laying and hatching of 11 unique axolotl pairs placed into reproductive enclosures and larval survival to 7 weeks and up to 12 months were examined. Physicochemical and biological parameters were estimated and compared among ponds.
5. The results from this study are encouraging as they suggest that two ponds have adequate conditions for axolotls to reproduce and for larvae and juveniles to survive.

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Local and remote physical processes driving variability of the planktonic system in the Juan Fernández Archipelago: A multidisciplinary framework providing conservation insights     

Carolina Parada  Billy Ernst  Sebastián Cornejo-Guzmán  Francisco Santa Cruz  Marco Sandoval Belmar  Pablo Rivara  Braulio Tapia  Stéphane Gauthier  Josefa Pino-Aguilera  Ruben Escribano  Carmen E. Morales 《水产资源保护:海洋与淡水生态系统》2021,31(2):253-272

1. The Juan Fernandez Ridge, a vulnerable marine ecosystem located far off the coast of central Chile and formed by several seamounts, guyots and three islands (Robinson Crusoe, Santa Clara and Alejandro Selkirk), has recently been declared a Coastal Marine Protected Area of Multiple Uses with several National Parks embedded in it.
2. Recent studies have highlighted the influence of remote and local oceanographic structures on the hydrographic dynamics of this ridge. However, there is still a gap in understanding how they affect the structure and dynamics of the surrounding insular planktonic communities.
3. A hydroacoustic and oceanographic survey was conducted during the austral spring (October 2016), including hydrographic and zooplankton sampling around Robinson Crusoe Island. Oceanographic features were identified and tracked using satellite data (chlorophyll-a (Chl-a) and sea surface temperature) and modelling results.
4. Two events of Chl-a increase relative to a threshold (>0.45 mg m⁻³) were forced by different physical processes, both affecting the western side of Robinson Crusoe Island. In event A during the cruise period, Chl-a subsurface maxima were associated with the arrival of a coastal meander originating on the continental shelf off Chile (remote process); the zooplankton was dominated by copepods and salps, with an evident coastal–oceanic gradient. In event B, Chl-a maxima were linked to a local upwelling forced by the intensification of a localized SSW wind. No influence of remote eddies or local Von Kármán vortices on Chl-a distribution was observed.
5. These findings highlight the influence of remote and local physical processes on the structure of planktonic communities around Robinson Crusoe Island. Understanding the variability of these mechanisms and their effects at the base of the pelagic food web is critical in adopting an ecosystem-level approach.

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Assessing landscapes: a case study of tree and shrub diversity in the seasonally dry tropical forests of Oaxaca, Mexico and southern Honduras     

James E. Gordon  William D. Hawthorne  German Sandoval 《Biological conservation》2004,117(4):429-442

Tropical dry forests, with their distinct and economically important diversity, are acknowledged conservation priorities because of alarming rates of forest conversion. Whilst it is realised that terrestrial conservation requires an understanding of landscape level patterns of diversity, forests are rarely assessed accordingly. Here we demonstrate that, in the case of the seasonally dry tropical forests of the Pacific watershed of Mesoamerica, landscape level assessment of woody diversity can inform decision making relevant to both between-landscape and within-landscape prioritisation. We report floristic surveys of dry forest landscapes in Oaxaca, Mexico and southern Honduras. It is noted that these forests are floristically similar to other seasonally dry tropical forests in the neotropics. By calculation of Genetic Heat Indices, a relative measure of the concentration of restricted range species in a sample, we determine that the conservation of the tree diversity of the coastal lowlands of Oaxaca should be prioritised over that of southern Honduras. The current conservation status of forested areas in Oaxaca is briefly described. We suggest that the greater degree of anthropogenic disturbance in southern Honduras may explain the relative lack of restricted range species there. We argue that some forest fallows can act as analogues of mature forest and therefore landscape elements other than mature forest need to be included in forest conservation assessments. We conclude that diversity sampling of any forest type should not be limited to mature forests, but extended to other elements of forested landscapes.  相似文献   

Canopy structure analysis for estimating forest regeneration dynamics and growth in <Emphasis Type="Italic">Nothofagus pumilio</Emphasis> forests     

Guillermo J. Martínez Pastur  Pablo L. Peri  Juan M. Cellini  María V. Lencinas  Marcelo Barrera  Horacio Ivancich 《Annals of Forest Science》2011,68(3):587-594

•Introduction   

Silviculture systems applied in Nothofagus pumilio forests are based on opening the canopy to stimulate natural regeneration by modifying light and soil moisture. The objective is to evaluate regeneration dynamics of N. pumilio along different forest canopy and solar radiation gradients.  相似文献   

Dissolved and Particulate Heavy Metals in the Salado River (Santa FE, Argentina)     

Marcos Gallo  Alfredo Trento  Ana Alvarez  Horacio Beldoménico  Darío Campagnoli 《Water, air, and soil pollution》2006,174(1-4):367-384

The objective of this work is to analyze Fe, Mn, Cr, Cd, Cu, Pb, and Zn distributions in the water column in terms of total, dissolved, and particulate concentrations in the Salado River (Santa Fe – Argentina); their relationship with total, dissolved and suspended solids; and the impact of two pollution sources on the watercourse: a stream that collects domestic and industrial wastewater discharges of the region and a direct discharge that releases urban and industrial effluents to the river. Water samples obtained from 5 surveys were analyzed. The Salado River transported a load of heavy metals that ranged from 700 g/s to 2200 g/s of Fe, 20 g/s to 60 g/s of Mn and 1 g/s to 3 g/s of Cr. Results show that most metals were found in particulate form, that the metal input from the direct discharge may be significant at low water levels, whereas a lesser impact was produced by the stream, and that both pollution sources were negligible at high water levels.  相似文献   

PRENATAL SONOGRAPHIC DIAGNOSIS OF FETAL DEATH AND HYDRANENCEPHALY IN TWO CHIHUAHUA FETUSES     

RobertDe  J. Cruz  DVM  Manuel S.  Alvarado  DVM  MS  Jorge E.  Sandoval  DVM  Eloina  Vilchez  DVM 《Veterinary radiology & ultrasound》2003,44(5):589-592

Hydranencephaly and fetal death was diagnosed in two of three fetuses during the abdominal sonographic examination of a 2.5-year-old, intact female Chihuahua that had clinical signs of dystocia 63 days after mating. A cesarean section was performed and one live normal puppy was present. Two dead puppies, each with a markedly enlarged and fluid filled skull were removed.  相似文献