Hematology of natural bovine trypanosomosis in the Brazilian Pantanal and Bolivian wetlands.

We report hematological changes observed in natural cases of bovine trypanosomosis due to Trypanosoma vivax in beef and dairy cattle from Bolivian wetlands and Pantanal, Brazil. The main hematologic changes produced by T. vivax infections were anemia and severe leucopenia. The cattle presented macrocytic hypochromic anemia. The leukocyte changes were characterized by relative lymphocytosis and monocytosis and decrease in the neutrophil counts. The clinical signs were lachrymation, progressive weakness, marked weight loss, inappetence, diarrhea and abortions during the third trimester of pregnancy.     

Analysis of uniformity of sprinkle irrigation in a semi-arid area

One of the most appropriate sprinkler systems for arid or semi-arid areas – where a great deal of irrigating water is required – are the permanent set systems and the continuous-move laterals. To know the reality of water application in this type of areas, many field evaluations of solid set systems and centre pivot irrigation were conducted in Castilla-La Mancha region (Spain). The main factors affecting water application and evaporation and drift losses with these systems (pressure, wind speed, sprinkler type, etc.) were analysed. A set of performance guidelines and recommendations for the design and management of sprinkle irrigation is presented to attain the highest uniformity and efficiency in water application in semi-arid areas. To use working pressure as low as possible, but with sprinklers that produce a great deal of middle size water drops along with night irrigation for minimising evaporation and drift losses are important aspects.     

Organizational learning through participatory research: CIP and CARE in Peru

Participatory research (PR) has been analyzed and documented from different points of view, with emphasis on the benefits generated for farmers. The effect of PR on organizational learning has, however, received little attention. This paper analyzes the interaction between a research and a development institution, the International Potato Center (CIP) and CARE in Peru, respectively, and makes the case that PR can contribute to creating a collaborative learning environment among organizations. The paper describes the evolution of the inter-institutional collaborative environment between the two institutions for more than a decade, including an information-transfer period (1993–1996), an action-learning period (1997–2002), and a social-learning period (2003–2007). Several lessons learned from each period are described, as are changes in institutional contexts and stakeholders’ perceptions. The case shows that research and development-oriented organizations can interact fruitfully using PR as a mechanism to promote learning, flexibility in interactions, and innovation. Interactions foster the diffusion of information and the sharing of tacit knowledge within and between organizations, which in turn influences behavior. However, the paper also argues that long-term inter-organizational interactions are needed to facilitate learning, which can be used to influence the way organizations implement their interventions in a constantly changing environment.     

Partial resistance to a Fusarium root disease in Egyptian white lupin landraces

A Fusarium sp. root pathogen of lupin is the causal agent of the most important disease that affects the cultivation of white lupin (Lupinus albus L.) in Egypt. The aim of our research was to investigate whether host resistance to Fusariumroot disease was available in Egyptian landraces ofLupinus albus. Five Fusarium isolates collected from white lupin samples in Egypt were tested with an Egyptian landrace and a French cultivar. The most aggressive isolate was used to screen an additional 15 Egyptian landraces, two cultivars released in Egypt after selection among landraces, one Polish cultivar, and two French cultivars. The assessment of host response to Fusarium was performed in a field, and under controlled conditions in a greenhouse pot experiment. Most landraces and the two Egyptian cultivars showed better resistance with good accordance between field and pot experiment. This experiment showed that Egyptian genetic resources of white lupin possess partial resistance to Fusarium root rot. Egyptian germplasm may be an alternative genetic source for incorporating partial resistance to Fusarium root rot into the breeding pools. This revised version was published online in July 2006 with corrections to the Cover Date.     

Genetic diversity, hybrid performance, and combining ability for yield in Musa germplasm

Genome size variation occurs within and across generations in Musa spp., which reduces the predictive accuracy of parental performance on progeny value for yield and other traits with complex inheritance. Parental selection through progeny testing of prospective parents is required to achieve further genetic gains. This was carried out in this study, using a factorial mating design involving five 4x females and five 2x males. Genetic differences among offspring families were essentially due to differences in additive effects of the parents. Thus, little recombinative heterosis can be expected upon 4x-2x cross-breeding, and breeding strategies should target the development of 4x and 2x cultivars by accumulation of favorable alleles through recurrent selection within each ploidy pool. Offspring yield was positively correlated with parental GCAs but not with mid-parent values. Hybrid performance was also associated but not significantly correlated with genetic similarity indices based on both pedigree and molecular data. This study further suggests that current genetic models may not be adequate for populations with intergeneration genome size polymorphism. This revised version was published online in July 2006 with corrections to the Cover Date.     

Identification of table grape cultivars (Vitis vinifera L.) by the isoenzymes from the woody stems

Results from the identification of a collection of 43 table grape (Vitis vinifera L.) cultivars by isoenzymes from woody stems are presented. Plant extracts were separated by polyacrylamide gel electrophoresis. Isoenzyme analysis was carried out for peroxidases, catechol oxidase, glutamate oxalacetate transaminase, superoxide dismutase, esterases, and acid phosphatase. The last two systems were not adequate, while the rest showed a more or less marked polymorphism. Catechol oxidase was the system with the highest level of polymorphism. The combination of the zymograms allowed the separation of 31 out of the 43 studied cultivars. The other 12 cultivars were separated in five groups. The use of this methodology for differentiation of grapevine cultivars is recommended.     

Factors influencing half‐pearl (mabe) production and quality in the red abalone Haliotis rufescens

The factors influencing half‐pearl (mabe) production in the red abalone Haliotis rufescens were investigated, as a strategy to optimize the technology for the development of a pearling industry in Chile. The effects of abalone size (small, large), implant position (dorsal, central, ventral and their combinations), and number of nuclei (one, two, three) were analysed on the quantity, thickness of the nacre layer and quality (shape, colour, lustre, defects) of the mabe produced. The size of abalone did not exert a clear influence on the quantity and quality of mabe, but the position on the shell (firstly) and number of nuclei (secondly) did. More mabe, with thicker nacre, brighter lustre and fewer defects occurred in small or large abalone implanted with only one nucleus on dorsal position. In contrast, small and large abalone implanted in the ventral position formed less mabe, with thinner nacre, poor lustre and more defects. This likely occurs because mantle tissue folds at the ventral position and does not always cover the nucleus, leaving it partially or totally exposed. Most of the pearls were categories AA in small abalone and A in large abalone; only three AAA gems were produced in large abalone with one nucleus on dorsal position or with three nuclei (DCV). Based on these results, we recommend implanting abalone at 60–100 mm shell length, with only one nucleus on the dorsal position.     

Trophic mass balanced models and dynamic simulations of benthic communities from La Rinconada Marine Reserve off northern Chile: network properties and multispecies harvest scenario assessments

• 1. Mass balanced trophic models and dynamic simulations of two benthic ecological systems from La Rinconada Marine Reserve (Antofagasta Bay, SE Pacific) were constructed.
• 2. The scallop Argopecten purpuratus is the most important benthic resource in La Rinconada Marine Reserve, followed by the carnivorous snail Thais chocolata, and the filter‐feeder bivalves Tagelus dombeii and Transennella pannosa.
• 3. Information on biomass, P/B ratios, catches, food spectrum, consumption, and dynamics of commercial and non‐commercial species was obtained and examined using Ecopath with an Ecosim software package.
• 4. The bivalves A. purpuratus and T. dombeii represented the most abundant compartments in the studied subsystems. Of the carnivores, the snail T. chocolata was dominant, followed by the crabs Cancer spp. and the functional group of large epifauna.
• 5. The two subsystems presented similar values of system throughput. The mean trophic level of their fisheries also reached similar magnitudes (2.0), showing that the harvests in each system concentrated on secondary producers. Likewise, both subsystems presented similar A/C ratios (29.9 and 30.3), suggesting that they were immature.
• 6. The results obtained using mixed trophic impact (MTI) and Ecosim (increasing the fishing mortality F_i by four times) showed that only four species propagated the highest direct and indirect effects. Coincidentally, these species are the most economically important and the changes produced by the scallop A. purpuratus are noteworthy.
• 7. With regard to the system recovery time (SRT) estimates, only three species or functional groups presented the highest magnitudes, from highest to lowest: the sea star Luidia magallanica, the scallop A. purpuratus, and the crabs Cancer spp.
• 8. The topological keystone indexes of Jordán and Libralato had divergent results. According to Jordán's index, the keystone species were L. magallanica, Cancer spp., and detritus; whereas Libralato's index showed phytoplankton to be the keystone species.
• 9. Based on the results obtained, it is concluded that trophic mass balanced models and simulated management scenarios have considerable value for planning interventions and manipulations or for planning more sustainable management strategies in La Rinconada Marine Reserve. Copyright © 2009 John Wiley & Sons, Ltd.

     

Dynamic and spatial models of kelp forest of Macrocystis integrifolia and Lessonia trabeculata (SE Pacific) for assessment harvest scenarios: short‐term responses

1. Dynamic and spatial models of the kelp forest off northern Chile (SE Pacific coast) were constructed using the Ecosim and Ecospace theoretical frameworks based on a previously mass‐balanced trophic model using Ecopath II software. 2. The biomass of Macrocystis integrifolia and Lessonia trabeculata blades constituted the most relevant compartments or variables of the ecosystem studied. 3. The relative ascendency (A/C) of 35.5% suggests that this ecosystem is immature, but resistant to disturbances (e.g. fisheries). 4. The results obtained using mixed trophic impacts (MTI) show that both brown macroalgae produced relatively similar quantitative and qualitative effects, however, the predictions based on Ecosim clearly show that L. trabeculata experienced the most relevant direct and indirect effects. 5. The highest values of system recovery time obtained by Pinguipes chilensis and the other seastar group suggest that both compartments could be considered to be top predator species with strong top‐down control. 6. The exploitation of kelp blades as a new harvest strategy appears to be ecologically sustainable. 7. The Ecospace trophic‐spatially explicit model shows that exploitation exerted separately by habitat generates a similar pattern of direct and indirect effects. These results suggest that a habitat rotation of fisheries would not be justified.Copyright © 2010 John Wiley & Sons, Ltd.     

Apparent digestibility and protein quality evaluation of selected feed ingredients in Seriola dumerili

The apparent digestibility coefficients (ADCs) of dry matter, crude protein, crude lipid, and amino acids in fish, krill, squid, meat, defatted krill, soybean, wheat gluten, wheat, camilina, pea, sunflower, and fava bean meals were determined for juvenile Seriola dumerili. The results showed that the ADC of dry matter for yellowtail ranged from 57.7 to 87.2% for animal ingredients and from 42.2 to 82.2% for plant ingredients. An ADC of protein exceeding 90% was observed in fishmeal, while camilina meal and fava bean meal presented the lowest values. Pea meal presented the lowest lipid ADC (83.5%). The availabilities were generally higher in animal ingredients than those in vegetal ones. Except camilina and fava bean meal, the other ingredients appear to be favorable for S. dumerili diets, especially the ones from animal sources. Lower case chemical score values (minimum value from amino acid ratios [AARs]) were obtained in some vegetal ingredients (14–18%), while the highest ones were observed in marine ingredients (69–88%). According to Oser's Index, the most balanced protein for yellowtail with regard to essential amino acids was in krill, defatted krill, and fishmeal (92–96%). So, animal sources are suitable as protein ingredients, but they could be enhanced through some essential amino acid supplementation.