Canine visceral leishmaniasis in urban and rural areas of Northeast Brazil

The purpose of this study was to determine the clinical and laboratory profiles of canine leishmaniasis in two distinct areas. Dogs from urban and rural areas were examined. The population studied in the metropolitan area included 54 dogs. Of these, 20 (37%) animals did not present with any signs suggestive of visceral leishmaniasis (VL). Among these, only eight were confirmed negative by ELISA (rK39 and CE) and 12 dogs, clinically negative for leishmaniasis, were seropositive by ELISA (rK39 and CE). Thinness, conjunctivitis and onychogryphosis were the most frequent clinical signs in the urban areas, followed by crusty lesions, alopecia, ulcerated lesions, hyperkeratosis and exfoliation. In the metropolitan area human VL cases occurred mainly in 1991, 1992, 1999 and 2000. In the rural areas the ELISA rK39 test detected a seroprevalence of 11.3% and ELISA CE (Leishmania crude extract) of 20.6%. Thirty-nine dogs were examined 6 months after the first visit. Serological exams using rK39 antigen showed seroconversion of only one dog, whereas Leishmania CE showed seroconversion of 13 (33.4%) dogs. In this rural environment 83.3% of the positive dogs were asymptomatic. Lutzomyia intermedia and Lu. longipalpis were the most predominant sandfly vector species. Amastigotes were identified in spleen and liver fragments of symptomatic necropsied animals. PCR amplification of DNA isolated from promastigote culture indicated that the species was Leishmania chagasi. This finding suggests that delayed diagnosis and euthanasia of potentially infectious animals may occur with an increased transmission risk to sandflies and subsequently to humans.     

A Comparison of 18Oδ Composition of Water Extracted from Suction Lysimeters, Centrifugation, and Azeotropic Distillation

The representativeness of soil pore water extracted by suction lysimeters in ground-water monitoring studies is a problem that often confounds interpretation of measured data. Current soil water sampling techniques cannot delineate from which soil volume a pore water sample is extracted, neither macroscopic, microscopic, or preferential flowpath. This research was undertaken to compare δ¹⁸O and Br^? values of extracted suction lysimeters samples from intact soil cores with samples obtained by the direct extraction methods of centrifugation and azeotropic distillation. Also, the study was concerned with determining what portion of soil pore water is sampled by each method and explaining differences in concentrations of the extracted water from each method to allow a determination of the accuracy and viability of the three methods of extraction. Intact soil cores (30 cm diameter by 40 cm height) were extracted from two different sites. Site 1 was rapid infiltration basin number 50, near Altamonte Springs in Seminole County, Florida. Site 2 was the Missouri Management System Evaluation Area (MSEA) near Centralia in Boone County, Missouri. Isotopically (¹⁸Oδ) labeled water and bromide concentrations within water samples taken by suction lysimeters was compared with samples obtained by methods of centrifugation and azeotropic distillation. The ¹⁸Oδ water was analyzed by mass spectrometry while bromide concentration, applied in the form of KBr was measured using standard IC procedures. Water collected by centrifugation and azeotropic distillation data were about 0.25‰ more negative than that collected by suction lysimeter values from a sandy soil and about 2–7‰ more negative from a well structured soil. Results indicate that the majority of soil water in well-structured soil is strongly bound to soil grain surfaces and is not easily sampled by suction lysimeters. In cases where a sufficient volume of water has passed through the soil profile and displaced previous pore water, suction lysimeters will collect a representative sample of soil pore water from the sampled depth interval. It is suggested that for stable isotope studies monitoring precipitation and soil water, suction lysimeter be installed at shallow depths (10 cm). Samples should also be coordinated with precipitation events. The data also suggest that each extraction method samples a separate component of soil-pore water. Centrifugation can be used with success, particularly for efficient sampling of large areas. Azeotropic distillation is more appropriate when strict qualitative and quantitative data on sorption desorption, and various types of kinetic studies may be needed.     

Experimental infection of cattle, sheep and pigs with 'Hobi'-like pestivirus

To date, limited information is available on the ability of 'Hobi'-like pestiviruses (putative bovine viral diarrhoea 3) to infect and cause disease in animal species traditionally affected by pestiviruses. In order to obtain new insights into host range and pathogenic potential of this atypical pestivirus, BVDV-seronegative calves (n=5), lambs (n=5) and piglets (n=5) were experimentally infected with the European 'Hobi'-like strain Italy-1/10-1, whereas two animals per species served as uninfected controls. Appearance of clinical signs, leukopenia, viremia, viral shedding and seroconversion were monitored for 28 days post-infection. Calves and lambs were successfully infected, displaying respiratory signs (nasal discharge), moderate hyperthermia and leukopenia, viremia and viral shedding through the nasal and faecal routes. Antibody responses were observed in both animal species by ELISA and virus neutralisation assays. In contrast, inoculated piglets did not display any clinical signs nor leukopenia and viral RNA was not detected in any biological samples. Nevertheless, the presence of detectable antibodies by virus neutralisation accounted for a successful, albeit limited infection of these animals.     

Partially defatted black soldier fly larva meal inclusion in piglet diets: effects on the growth performance,nutrient digestibility,blood profile,gut morphology and histological features

Background: The aim of this trial was to investigate the effects of different inclusion levels of a partial y defatted black soldier fly(BSF, Hermetia il ucens L.) larva meal on the growth performance, nutrient digestibility, blood profile, gut morphology and histological features of piglets. A total of 48 newly weaned piglets were individual y weighed(initial body weight(IBW): 6.1 ± 0.16 kg) and randomly al ocated to 3 dietary treatments(4 boxes as replicates/treatment and 4 animals/box). BSF larva meal was included at increasing levels(0% [BSF0], 5% [BSF5] and 10% [BSF10]) in isonitrogenous and isoenergetic diets formulated for two feeding phases: I(from d 1 to d 23) and I(from d 24 to d 61). The weight gain(WG), average daily gain(ADG), average daily feed intake(ADFI) and feed conversion ratio(FCR) were calculated for each feeding phase and for the whole trial. The haematochemical parameters and nutrient digestibility of the piglets were also evaluated. A total of 3 piglets per box were slaughtered on d 61 and the slaughtered piglets were submitted to morphometric investigations and histopathological examinations.Results: No overal significant differences were observed for growth performance(P 0.05), except for the ADFI of phase I, which showed a linear response to increasing BSF meal levels(P 0.05, maximum for the BSF10 group). Dietary BSF meal inclusion did not significantly influence the blood profile, except as far as monocytes and neutrophils are concerned,and these showed a linear and quadratic response, respectively, to increasing BSF meal levels(P 0.05, maximum for the BSF10 and BSF5 groups, respectively). On the other hand, the nutrient digestibility, gut morphology and histological features were not affected by dietary BSF meal inclusion(P 0.05).Conclusions: The obtained results show that a partial y defatted BSF larva meal can be used as a feed ingredient in diets for weaned piglets without negatively affecting their growth performance, nutrient digestibility, blood profile, gut morphology or histological features.     

Presence and distribution of leptin and its receptor in the gut of adult zebrafish in response to feeding and fasting

Leptin is an anorectic hormone secreted mainly by peripheral adipocytes but also by other central and peripheral tissues. It acts by means of a receptor called OB‐R, influencing not only appetite and body mass but being also involved in many fields like endocrinology, metabolism and reproduction. Immunohistochemistry and qRT‐PCR techniques were, respectively, used to demonstrate the presence of leptin and its receptor in the gut of adult zebrafish and to evaluate the leptin gene expression response to feeding and fasting. Immunoreactivity for the antibodies utilized was demonstrated in feeding but not in fasting fish, and the gene expression analysis corroborates the data obtained by immunohistochemistry. Therefore, all the obtained results support the hypothesis of the role of this hormone in food regulation in zebrafish.     

Degradation of isoproturon and bentazone in peat- and compost-based biomixtures

BACKGROUND: The composition and properties of a biomixture used in a biobed are decisive for pesticide sorption and degradation. This study was performed to investigate the capability of compost‐based substrates in mixtures with citrus peel and vine branch straw and peat‐based substrates in mixtures with soil and vine branch straw at different levels in order to degrade isoproturon and bentazone. RESULTS: Dissipation and mineralisation rates of both pesticides were determined, and metabolic activity was followed as respiration. Compost‐based substrates showed faster pesticide dissipation in the presence of lignocellulosic materials, as in garden compost and vine branch straw. The increasing content of vine branch straw in peat‐based substrates does not seem to affect dissipation of the parent compounds. Low mineralisation rate was observed in all treatments. CONCLUSION: Higher pesticide degradation was observed in the lignocellulosic substrates, probably because of the development of lignin‐degrading microorganisms which have shown to be robust and are able to degrade recalcitrant pesticides. Copyright © 2010 Society of Chemical Industry     

Enteromyxum leei infection in parrotfish,Sparisoma cretense: Histopathological,morphological and molecular study

Enteromyxum leei (Myxozoa) has been identified as the aetiological agent of morbidity and mortality in captive feral parrotfish, Sparisoma cretense held at the facilities of Cretaquarium, the public aquarium of the Hellenic Centre for Marine Research in Crete. The parasite caused substantial mortality to the parrotfish exceeding 60% over a period of 3.5 months. Here we describe the course of disease, the effects of the parasite on the host based on histopathological observations and we provide morphological and molecular data on the parasite.     

Effect of intermittent drought on grain yield and quality of rice (Oryza sativa L.) grown in Rwanda

The climate change will contribute drought and temperature extremes to rice growing systems, especially when cultivated in equatorial regions. To evaluate opportunities to cultivate and breed drought-tolerant rice, seven rice cultivars were evaluated in Rwanda for recurring morphological drought scores, grain yield and components, and quality characteristics. The cultivation conditions, that is site and drought treatment, impacted morphological drought scores, growth and yield attributes, while cultivar affected quality attributes. Thus, site showed a higher impact on grain yield and components than drought and cultivar, with generally a reduced grain yield at the low-temperature site, as a result of low spikelet fertility. Morphological drought scores were generally increased by drought, while drought at the reproductive stage at the high-temperature site was negative for yield and its components. The cultivars “Intsindagirabigega” and “Jyambere” were adapted to high-temperature site conditions. The cultivar “Intsindagirabigega” had the highest amylose content, and “Mpembuke,” the highest antioxidant capacity. Thus, climate change with increased temperature and drought extremes may increase rice productivity in cool areas, while especially drought at reproductive stage will be detrimental in low altitude areas with high temperature. Cultivar variation indicated opportunities for selection and breeding of climate change tolerant rice cultivars which should be of immediate priority.     

Effects of Various Levels of Silica Ash in the Diet of Juvenile Red Drum,Sciaenops ocellatus

The demand for alternative feedstuffs to fish meal is anticipated to continue increasing due to fish meal's limited supply and escalating price. One group of alternative feedstuffs includes lipid‐extracted algae (LEA) by‐products from algae production for biofuels. Most LEA by‐products are known to contain relatively high levels of ash ranging from 20 to 30% of dry weight. Thus, inclusion of LEA by‐products in aquafeeds may contribute a substantial amount of ash, which potentially could have negative effects on utilization of other nutrients. To study the ash component of LEA by‐products, diatomaceous earth (DE) was used as a homogeneous source of silica ash. Therefore, two feeding trials were conducted with red drum, Sciaenops ocellatus, in a closed, recirculating system to evaluate the effects of graded levels of dietary silica ash. In Experiment 1, semi‐purified diets were formulated to contain 35% crude protein, with DE included at 0, 5, 10, 20, or 30% of dry weight in place of cellulose to provide diets with analyzed ash levels of 8.6, 12.4, 16.7, 25.5, and 33.8% of dry weight in a regression design. Similar diets were fed in Experiment 2 but DE and cellulose were restricted to no more than 20% of diet. Each diet was fed to triplicate groups of juvenile fish (initial average weight of 1.4 ± 0.2 and 2.3 ± 0.1 g) for 8 wk. In both experiments it was apparent that red drum did not respond negatively to even the highest dietary ash levels based on weight gain, feed efficiency, survival, or body composition. No apparent histological changes in the gastrointestinal tract of fish fed the graded levels of ash were observed. Therefore, inclusion of algae by‐products in diets of red drum will not be limited due to their contribution of ash.