Elevated CO2 reduces whole transpiration and substantially improves root production of cassava grown under water deficit

We evaluated the possibility of elevated CO₂ concentration ([CO₂]) to reduce the negative effect of drought on growth and physiological parameters of cassava (Manihot esculenta Crantz). Plants were grown with 390 ppm or 750 ppm of CO₂, under well-watered or under water deficit conditions. The study was conducted in a climate-controlled greenhouse using 14 L pots, for 100 days. For any value of fraction of transpirable soil water (FTSW) the carbon assimilation was always higher for plants grown under elevated [CO₂]. Still, elevated [CO₂] reduced the negative effect of drought on transpiration, water use efficiency, all growth measures and harvest index. Elevated [CO₂] increased the dry matter of tuber roots (DMTR) of well-watered plants by 17.4%. The DMTR of plants grown under water deficit were 124.4 g and 58.9 g, respectively, for plants under elevated and ambient CO₂, an increase of 112%. Thus, the CO₂ effect was relatively stronger to the production of tuberous roots when cassava were subjected to water-deficit. Our results suggest that cassava tuber production might be resilient to changes in precipitation that will accompany higher atmospheric CO₂ and reinforce cassava as a specie that can significantly contribute to mitigate hunger in a changing climate environment.     

Emergence and Partial Characterization of Rice Stripe Necrosis Virus and its Fungus Vector in South America

A new disease of rice, known as entorchamiento (crinkling), was first noticed in the Department of Meta, Colombia, in 1991. Symptoms include seedling death, foliar striping and severe plant malformation. Tissue extracts and purified preparations from diseased rice plants, contained virus-like particles ca. 20nm in diameter, with a bimodal length of 260 and 360nm. Particle aggregates were also observed in the cytoplasm of infected rice leaf cells. Electrophoretic analyses of purified preparations and dsRNA extracts, revealed a single protein species of M 22,500, and four dsRNA bands ca. 6300, 4600, 2700 and 1800bp in size. Cystosori, characteristic of plasmodiophorid fungal vectors of plant viruses, were consistently observed in the roots of diseased rice plants. PCR and sequence analyses of amplified fungal DNA products from infected rice roots, revealed that the putative fungus vector was Polymyxa graminis. A Western blot of tissue extracts obtained from crinkled rice plants from Colombia, using antiserum against a West African isolate of rice stripe necrosis furovirus (RSNV), resulted in the detection of a protein band of approximately M 22,000. The RSNV antiserum recognized the Colombian virus isolate in serologically specific electron microscopy tests. These results confirm the presence of RSNV in the Americas.     

Hematologic and biochemical reference ranges for captive California condors (Gymnogyps californianus).

To provide proper medical evaluation and care for the endangered California condor (Gymnogyps californianus), veterinarians need accurate hematologic and biochemical reference ranges. A retrospective study of blood samples from captive California condors housed at the San Diego Wild Animal Park assessed the samples by sex and age of condor to determine serum biochemical and hematologic reference ranges, including lead and zinc levels. Condors were grouped by age as follows: group 1 included birds less than 30 days of age; group 2 included birds between 30 days and 6 mo of age; group 3 included birds between 6 mo and 5 yr of age; group 4 included all birds greater than 5 yr of age. Significant differences between sexes included higher chloride, cholesterol, and total plasma protein concentration in males as compared to females (P < 0.05). Significant differences between age groups were identified in glucose, potassium, phosphorus, calcium, albumin, total plasma protein, globulin, cholesterol, bile acid, and zinc concentrations, as well as aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, and creatine phosphokinase activities (P < 0.05). Additionally, significant differences between age groups were noted in white blood cell count, hematocrit, heterophils, lymphocytes, and eosinophils (P < 0.05). A steady increase in glucose and a decrease in alkaline phosphatase and lactate dehydrogenase activities, as well as cholesterol, bile acid, calcium, and phosphorus concentrations, were correlated with age (P < 0.05). Following application of statistical analysis, condors less than 6 mo of age were identified as unique compared to older cohorts; therefore, two reference ranges are proposed by calculating a 90% confidence interval. Reference ranges obtained from other published avian data, including those for psittaciformes, ratites, galliformes, anseriformes, and raptors, were similar to condors in this study.     

Influence of rain intensity and rapeseed oil ethoxylate adjuvants on biological efficacy of glyphosate

Journal of Plant Diseases and Protection - In order to investigate the impact of rapeseed oil ethoxylates (RSO) as tank-mix-adjuvants on the biological efficacy of glyphosate, three selected weed...     

Agroforestry adoption in the Calakmul Biosphere Reserve,Campeche, Mexico

Since farmers engage in a complex, dynamic process of learning-by-doing, evaluating economic incentives, and assessing risks in deciding whether to adopt agroforestry systems, a multi-pronged research approach is required for a complete analysis of adoption potential and to develop effective technological and institutional interventions. A case study is presented for using multiple approaches to analyse the potential for reforestation and improving livelihoods of small farmers through the adoption of agroforestry systems in the Calakmul Biosphere Reserve in Campeche, Mexico. Specifically, the results from a participatory research project are combined with revealed preference analysis of a household survey to analyse past adoption decisions and preferences, identify limitations, test and evaluate alternatives, and evaluate methods for risk reduction. The participatory research trials suggest that continuous intercropping and line cleaning are equally effective for tree growth, while continuous cropping during the first years offers the additional advantage of early returns to investments through crop production. Farmer participation in the research process, planning of production systems, and annual evaluations, assisted farmers and researchers in identifying limitations, testing and evaluating alternatives, and improving the viability and sustainability of systems. The revealed preference analysis provides insights as to which households are most likely to initially adopt agroforestry systems developed through the participatory research trials. In general, households that originated from the Yucatan Peninsula with more education, more experience both in age of the head of household and technical and project experience, higher incomes, and those that had cleared more forestland were more likely to have experimented with agroforestry systems in the past.     

Evaluation of an epidemic of sporotrichosis in cats: 347 cases (1998-2001)

OBJECTIVE: To evaluate characteristics of a large epidemic of sporotrichosis in cats. DESIGN: Retrospective study. ANIMALS: 347 cats with naturally acquired infection with Sporothrix schenckii. PROCEDURE: Medical records were reviewed for data regarding clinical, mycologic, histopathologic, and routine hematologic and serum biochemical findings; assays for FIV-specific antibodies and FeLV antigen; antifungal treatment; and follow-up. RESULTS: Lesions varied from small papules to extensive zones of necrosis.Ten cats had no skin lesions, 114 had skin lesions at a single site, 86 had skin lesions in 2 sites, and 137 had skin lesions in 3 or more sites. Respiratory tract signs were observed in 154 cats and were the most frequent extracutaneous sign. Anemia, leukocytosis with neutrophilia, hypoalbuminemia, and hyperglobulinemia were the main blood abnormalities. Antibodies against FIV were detected in 28 cats, FeLV antigen was detected in 2 cats, and both were detected in 1 cat among 142 cats tested. During the study, 118 cats were lost to follow-up and 124 died. Of 266 cats that were treated, 68 were cured. Complete healing of the lesions was observed regardless of the presence of extracutaneous signs, general condition, treatment schedule, or coinfection with FIV. CONCLUSIONS AND CLINICAL RELEVANCE: Feline sporotrichosis was evident in subclinical to severe forms; however, cats can respond well to regular and prolonged antifungal treatment.     

Threatened aquatic Andean frogs and mining activity in the Lithium Triangle of South America: Can both coexist?

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Wood anatomy and biometric parameters variation of Eucalyptus globulus clones

Variation in wood anatomy and biometric variables was studied in 14 7-year-old Eucalyptus globulus clones grown in a clonal trial in Arauco, Bio-Bio Region, Chile. Biometric characteristics were measured for each tree and the anatomical variables were measured at three radial positions by image analysis on transverse microsections cut from radial increment cores sampled at breast height. Results showed, that among clones wide ranges of variation were found for vessel frequency, vessel area and vessel coverage. However, narrow ranges of variation were found for fiber wall thickness, fiber diameter and lumen diameter. From pith to bark, mean vessel area and vessel coverage increased gradually, whereas the vessel frequency decreased. The fiber wall thickness did not differ significantly from pith to bark. Mean fiber and lumen diameters showed the same radial pattern, increasing from pith to the midpoint of the radius to reach a plateau close to the bark. Furthermore, important commercial volume gains that can exceed 100% were found. Considering the commercial importance of tree volume, vessel and fiber anatomy in the pulping and papermaking process, it is suggested that the information given in this study may be used as an additional criteria for the selection of E. globulus.     

Site‐fidelity and movement patterns of bottlenose dolphins (Tursiops truncatus) in central Argentina: essential information for effective conservation

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