Biological effects of Physalis peruviana L. (Solanaceae) crude extracts and its major withanolides on Ceratitis capitata Wiedemann (Diptera: Tephritidae)

Biological effects of Physalis peruviana crude extracts and its major withanolides (withanolide E and 4-ß-hydroxywithanolide E) were investigated on larvae and adults of the fruit fly Ceratitis capitata. High concentrations of crude extracts (10000 and 35000 ppm) in larval diet caused 100% mortality while low concentration (1000 ppm) caused significative differences in larval mortality, development delay and puparia length. Withanolide E and 4-ß-hydroxywithanolide E (500 ppm) also produced significative mortality on larvae. The application of crude extracts to adults drinking vessels caused significative lethal effects at 10000 and 35000 ppm. These data indicate that P. peruviana crude extracts and its two major withanolides could be used to develop baits to control C.capitata.EEA ChubutFil: Cirigliano, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica; ArgentinaFil: Colamarino, I. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Zoología Agrícola; ArgentinaFil: Mareggiani, G. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Zoología Agrícola; ArgentinaFil: Bado, Silvina Graciela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; Argentin

Estudio preliminar de la estructura de la comunidad de artrópodos en un cultivo de cerezo (Prunus avium L.) en el valle inferior del rio Chubut (Región Patagonia Sur)

Esta experiencia se llevó a cabo en una chacra que presenta un cultivo de cerezo y otras especies de frutales. El objetivo fue conocer la estructura de la comunidad de artrópodos en dicho cultivo con fines de poder implementar a futuro acciones de manejo en un marco de sustentabilidad del agroecosistema. Para ello se colocaron en dicho predio trampas tipo veleta distribuidas en el predio, cuyo material capturado era recolectado cada 15 días y conservado en laboratorio, para su posterior clasificación. Se dio especial interés al Orden Hymenoptera. Los resultados en cuanto a los grupos hallados se analizó a la luz de la ubicación de las trampas. El conocimiento de la estructura de la comunidad de artrópodos en el cultivo resulta básico para comprender procesos que podrán resultar claves para el desarrollo de programas de control biológico conservativo.Eje: B4 Ambiente, naturaleza y agroecología (Relatos de experiencias)Facultad de Ciencias Agrarias y Forestale

Estudio preliminar de la estructura de la comunidad de artrópodos en un cultivo de cerezo (Prunus avium L.) en el valle inferior del rio Chubut (Región Patagonia Sur)

Esta experiencia se llevó a cabo en una chacra que presenta un cultivo de cerezo y otras especies de frutales. El objetivo fue conocer la estructura de la comunidad de artrópodos en dicho cultivo con fines de poder implementar a futuro acciones de manejo en un marco de sustentabilidad del agroecosistema. Para ello se colocaron en dicho predio trampas tipo veleta distribuidas en el predio, cuyo material capturado era recolectado cada 15 días y conservado en laboratorio, para su posterior clasificación. Se dio especial interés al Orden Hymenoptera. Los resultados en cuanto a los grupos hallados se analizó a la luz de la ubicación de las trampas. El conocimiento de la estructura de la comunidad de artrópodos en el cultivo resulta básico para comprender procesos que podrán resultar claves para el desarrollo de programas de control biológico conservativo.Eje: B4 Ambiente, naturaleza y agroecología (Relatos de experiencias)Facultad de Ciencias Agrarias y Forestale

Estudio preliminar de la estructura de la comunidad de artrópodos en un cultivo de cerezo (Prunus avium L.) en el valle inferior del rio Chubut (Región Patagonia Sur)

Esta experiencia se llevó a cabo en una chacra que presenta un cultivo de cerezo y otras especies de frutales. El objetivo fue conocer la estructura de la comunidad de artrópodos en dicho cultivo con fines de poder implementar a futuro acciones de manejo en un marco de sustentabilidad del agroecosistema. Para ello se colocaron en dicho predio trampas tipo veleta distribuidas en el predio, cuyo material capturado era recolectado cada 15 días y conservado en laboratorio, para su posterior clasificación. Se dio especial interés al Orden Hymenoptera. Los resultados en cuanto a los grupos hallados se analizó a la luz de la ubicación de las trampas. El conocimiento de la estructura de la comunidad de artrópodos en el cultivo resulta básico para comprender procesos que podrán resultar claves para el desarrollo de programas de control biológico conservativo.Eje: B4 Ambiente, naturaleza y agroecología (Relatos de experiencias)Facultad de Ciencias Agrarias y Forestale

Soil organic carbon dynamics and crop yield for different crop rotations in a degraded ferruginous tropical soil in a semi-arid region: a simulation approach

In recent years, simulation models have been used as a complementary tool for research and for quantifying soil carbon sequestration under widely varying conditions. This has improved the understanding and prediction of soil organic carbon (SOC) dynamics and crop yield responses to soil and climate conditions and crop management scenarios. The goal of the present study was to estimate the changes in SOC for different cropping systems in West Africa using a simulation model. A crop rotation experiment conducted in Farakô-Ba, Burkina Faso was used to evaluate the performance of the cropping system model (CSM) of the Decision Support System for Agrotechnology Transfer (DSSAT) for simulating yield of different crops. Eight crop rotations that included cotton, sorghum, peanut, maize and fallow, and three different management scenarios, one without N (control), one with chemical fertilizer (N) and one with manure applications, were studied. The CSM was able to simulate the yield trends of various crops, with inconsistencies for a few years. The simulated SOC increased slightly across the years for the sorghum–fallow rotation with manure application. However, SOC decreased for all other rotations except for the continuous fallow (native grassland), in which the SOC remained stable. The model simulated SOC for the continuous fallow system with a high degree of accuracy normalized root mean square error (RMSE)=0·001, while for the other crop rotations the simulated SOC values were generally within the standard deviation (s.d.) range of the observed data. The crop rotations that included a supplemental N-fertilizer or manure application showed an increase in the average simulated aboveground biomass for all crops. The incorporation of this biomass into the soil after harvest reduced the loss of SOC. In the present study, the observed SOC data were used for characterization of production systems with different SOC dynamics. Following careful evaluation of the CSM with observed soil organic matter (SOM) data similar to the study presented here, there are many opportunities for the application of the CSM for carbon sequestration and resource management in Sub-Saharan Africa

Correlations between peripheral parasite load and common clinical and laboratory alterations in dogs with visceral leishmaniasis

Intensity of peripheral parasite infection has an important role in the transmission of Leishmania spp. from one host to another. As parasite load quantification is still an expensive procedure to be used routinely in epidemiological surveillance, the use of surrogate predictors may be an important asset in the identification of dogs with high transmitting ability. The present study examined whether common clinical and laboratory alterations can serve as predictors of peripheral parasitism in dogs naturally infected with Leishmania spp. Thirty-seven dogs were examined in order to establish correlations between parasite load (PL) in multiple peripheral tissues and common clinical and laboratory findings in canine visceral leishmaniasis (CVL). Quantitative polymerase chain reaction was employed to determine PL in conjunctival swabs, ear skin, peripheral blood and buffy coat. Additionally, a series of hematological, biochemical and oxidative stress markers were quantified. Correlations between net peripheral infection and severity of clinical alterations and variation in laboratory parameters were assessed through a new analytical approach, namely Compressed Parasite Load Data (CPLD), which uses dimension reduction techniques from multivariate statistics to summarize PL across tissues into a single variable. The analysis revealed that elevation in PL is positively correlated with severity of clinical sings commonly observed in CVL, such as skin lesions, ophthalmic alterations, onycogriphosis, popliteal lymphadenomegaly and low body mass. Furthermore, increase in PL was found to be followed by intensification of non-regenerative anemia, neutrophilia, eosinopenia, hepatic injury and oxidative imbalance. These results suggest that routinely used clinical and laboratory exams can be predictive of intensity of peripheral parasite infection, which has an important implication in the identification of dogs with high transmitting ability

Ovine pedomics : the first study of the ovine foot 16S rRNA-based microbiome

We report the first study of the bacterial microbiome of ovine interdigital skin based on 16S rRNA by pyrosequencing and conventional cloning with Sanger-sequencing. Three flocks were selected, one a flock with no signs of footrot or interdigital dermatitis, a second flock with interdigital dermatitis alone and a third flock with both interdigital dermatitis and footrot. The sheep were classified as having either healthy interdigital skin (H), interdigital dermatitis (ID) or virulent footrot (VFR). The ovine interdigital skin bacterial community varied significantly by flock and clinical condition. The diversity and richness of operational taxonomic units was greater in tissue from sheep with ID than H or VFR affected sheep. Actinobacteria, Bacteriodetes, Firmicutes and Proteobacteria were the most abundant phyla comprising 25 genera. Peptostreptococcus, Corynebacterium and Staphylococcus were associated with H, ID and VFR respectively. Sequences of Dichelobacter nodosus, the causal agent of ovine footrot, were not amplified due to mismatches in the 16S rRNA universal forward primer (27F). A specific real time PCR assay was used to demonstrate the presence of D. nodosus which was detected in all samples including the flock with no signs of ID or VFR. Sheep with ID had significantly higher numbers of D. nodosus (104-109 cells/g tissue) than those with H or VFR feet

Dog skin parasite load, TLR-2, IL-10 and TNF-α expression and infectiousness

Visceral leishmaniosis is a zoonotic disease that is transmitted by Lutzomyia longipalpis sandflies. Dogs are the main peri-urban reservoir of the disease, and progression of canine leishmaniosis is dependent on the type of immune response elaborated against the parasite. Type 1 immunity is characterized by effective cellular response, with production of pro-inflammatory cytokines such as tumour necrosis factor alpha (TNF-α). In contrast, Type 2 immunity is predominantly humoral, associated with progression of the disease and mediated by anti-inflammatory cytokines such as interleukin 10 (IL-10). Although seemly important in the dynamics of leishmaniosis, other gene products such as toll-like receptor 2 (TRL-2) and inducible nitric oxide synthase (iNOS) exert unclear roles in the determination of the type of immune response. Given that the dog skin serves as a micro-environment for the multiplication of Leishmania spp., we investigated the parasite load and the expression of TLR-2, iNOS, IL-10 and TNF-α in the skin of 29 infected and 8 control dogs. We found that increased parasite load leads to upregulation of TLR-2, IL-10 and TNF-α, indicating that abundance of these transcripts is associated with infection. We also performed a xenodiagnosis to demonstrate that increased parasitism is a risk factor for infectiousness to sandflies

Effect of Lactobacillus acidophilus supernatants on body weight and leptin expression in rats

<p>Abstract</p> <p>Background</p> <p><it>Lactobacillus </it>extracts and supernatants have been used as probiotics in human and veterinary medicine for their ability to enhance wound healing and immunity. Previous data from our laboratory demonstrated that <it>Lactobacillus </it>supernatant (LS) stimulated wound healing, angiogenesis and proliferation of embryonic cells after topical application. This current study shows that LS after its administration into the cerebral ventricles of male rats exerts systemic effects.</p> <p>Methods</p> <p>The right lateral cerebral ventricle of young male rats was accessed through intracerebroventricular cannulation (ICV) under anesthesia and aseptic conditions. One group of control rats received saline solution, a second control group received 0.8 M lactic acid solution (to control for acidity of LS), and a third group received LS. The animals were sacrificed 12, 24, 48, 96 and 120 hours after the injection. Selected tissues were collected, fixed in 10% buffered formalin and used for immunohistochemistry and <it>in situ </it>hybridization. Other tissues were frozen and extracted for immunoblotting</p> <p>Results</p> <p>LS-injected animals had a slight decrease in body weight when compared to their initial weight and to both control groups. Using immunohistochemistry and <it>in situ </it>hybridization leptin expression was studied in multiple brain sections and peripheral adipose tissue of control and LS-injected rats. Strong cytoplasmic stain was observed by both techniques in neurons of the cerebral cortex, thalamus, hypothalamus, hippocampus and, to lesser degree, in the cells of the choroid plexus in the LS-injected rats. Control animals demonstrated much less intense staining in neurons located in the same regions using immunohistochemistry and almost no staining with <it>in situ </it>hybridization technique. Adipose tissue exhibited slight presence of leptin in LS-treated animals. In contrast no immunohistochemical staining for GM-CSF and TNFα was observed in brains from control and treated rats. Western blotting showed mild increase in leptin and leptin receptors in intestines and retroperitoneal adipose tissues of LS-injected rats.</p> <p>Conclusion</p> <p>This study demonstrates that direct administration of LS into rat CNS leads to a decrease in body weight of rats and an increase in the expression of leptin in specific areas of the brain and retroperitoneal adipose tissue.</p