Imidacloprid-Induced Impairment of Mushroom Bodies and Behavior of the Native Stingless Bee Melipona quadrifasciata anthidioides

Declines in pollinator colonies represent a worldwide concern. The widespread use of agricultural pesticides is recognized as a potential cause of these declines. Previous studies have examined the effects of neonicotinoid insecticides such as imidacloprid on pollinator colonies, but these investigations have mainly focused on adult honey bees. Native stingless bees (Hymenoptera: Apidae: Meliponinae) are key pollinators in neotropical areas and are threatened with extinction due to deforestation and pesticide use. Few studies have directly investigated the effects of pesticides on these pollinators. Furthermore, the existing impact studies did not address the issue of larval ingestion of contaminated pollen and nectar, which could potentially have dire consequences for the colony. Here, we assessed the effects of imidacloprid ingestion by stingless bee larvae on their survival, development, neuromorphology and adult walking behavior. Increasing doses of imidacloprid were added to the diet provided to individual worker larvae of the stingless bee Melipona quadrifasciata anthidioides throughout their development. Survival rates above 50% were only observed at insecticide doses lower than 0.0056 µg active ingredient (a.i.)/bee. No sublethal effect on body mass or developmental time was observed in the surviving insects, but the pesticide treatment negatively affected the development of mushroom bodies in the brain and impaired the walking behavior of newly emerged adult workers. Therefore, stingless bee larvae are particularly susceptible to imidacloprid, as it caused both high mortality and sublethal effects that impaired brain development and compromised mobility at the young adult stage. These findings demonstrate the lethal effects of imidacloprid on native stingless bees and provide evidence of novel serious sublethal effects that may compromise colony survival. The ecological and economic importance of neotropical stingless bees as pollinators, their susceptibility to insecticides and the vulnerability of their larvae to insecticide exposure emphasize the importance of studying these species

Sensitivity of the Cherenkov Telescope Array to a dark matter signal from the Galactic centre

We provide an updated assessment of the power of the Cherenkov Telescope Array (CTA) to search for thermally produced dark matter at the TeV scale, via the associated gamma-ray signal from pair-annihilating dark matter particles in the region around the Galactic centre. We find that CTA will open a new window of discovery potential, significantly extending the range of robustly testable models given a standard cuspy profile of the dark matter density distribution. Importantly, even for a cored profile, the projected sensitivity of CTA will be sufficient to probe various well-motivated models of thermally produced dark matter at the TeV scale. This is due to CTA's unprecedented sensitivity, angular and energy resolutions, and the planned observational strategy. The survey of the inner Galaxy will cover a much larger region than corresponding previous observational campaigns with imaging atmospheric Cherenkov telescopes. CTA will map with unprecedented precision the large-scale diffuse emission in high-energy gamma rays, constituting a background for dark matter searches for which we adopt state-of-the-art models based on current data. Throughout our analysis, we use up-to-date event reconstruction Monte Carlo tools developed by the CTA consortium, and pay special attention to quantifying the level of instrumental systematic uncertainties, as well as background template systematic errors, required to probe thermally produced dark matter at these energies

Factors associated with exclusive breastfeeding in children under four months old in Botucatu-SP, Brazil Factores asociados a la situación de lactancia materna exclusiva en niños menores de 4 meses en Botucatu-SP Fatores associados à situação do aleitamento materno exclusivo em crianças menores de 4 meses, em Botucatu-SP

This study aimed to identify factors associated with exclusive breastfeeding (AME) and the reasons mothers presented to introduce complementary feeding in the first four months of life. A total of 380 mothers (92.2%) of children under four months old vaccinated in a Multi-vaccination Campaign were interviewed. To identify factors associated to AME, univariate and multiple logistic regressions analyses were performed. Thirty-eight percent of the children were on AME; 33.4% consumed cow milk; 29.2% tea; and 22.4% water. The mothers justified introduction of cow milk by factors related to quantity/quality of maternal milk and "necessity" of the child. The use of a pacifier (odds ratio=2.63; CI95%=1.7-4.06) and difficulty to breastfeed (odds ratio=1.57; CI95%=1.02-2.41) were associated with the absence of AME. The populational attributable risk percentage for the use of a pacifier was estimated at 46.8 %. Thus, modifiable risk factors were associated with AME interruption.<br>El objetivo fue identificar factores asociados a la lactancia materna exclusiva (AME) y los motivos presentados por las madres para la introducción de alimentos complementares en los primeros 4 meses de vida. Se les entrevistaron a 380 madres (92,2%) de niños menores de 4 meses vacunados en una Campaña de Multivacunación. Para identificación de los factores asociados a la situación del niño con relación al AME, se realizaron análisis de regresión logísticas univariadas y múltiplas. En AME estaba el 38,0% de los niños; el 33,4% consumía leche de vaca; el 29,2% té y el 22,4% agua. Las madres justificaron la introducción de leche de vaca por factores relativos con la cantidad/calidad de la leche materna y "necesidad" del niño. El uso de chupete (odds ratio=2,63; IC95%=1,7-4,06) y relato de dificultad con la lactancia (odds ratio=1,57; IC95%=1,02-2,41) se asociaron a la ausencia de AME. El riesgo atribuible poblacional asociado al uso de chupete fue 46,8%. Así, factores modificables fueron identificados como de riesgo para interrupción de AME.<br>Objetivou-se identificar fatores associados ao aleitamento materno exclusivo (AME) e os motivos apresentados pelas mães para a introdução de alimentação complementar nos primeiros 4 meses de vida. Foram entrevistadas 380 mães (92,2%) de crianças menores de 4 meses vacinadas em Campanha de Multivacinação. Para identificação dos fatores associados à situação da criança em relação ao AME, realizaram-se análises de regressão logística univariadas e múltiplas. Em AME, estavam 38,0% das crianças; 33,4% consumiram leite de vaca; 29,2%, chás, e 22,4%, água. As mães justificaram a introdução de leite de vaca por fatores relativos à quantidade/ qualidade do leite materno e "necessidade" da criança. Uso de chupeta (odds ratio=2,63; IC95%=1,7-4,06) e relato de dificuldade com a amamentação (odds ratio=1,57; IC95%=1,02-2,41) associaram-se à ausência de AME. O risco atribuível populacional associado ao uso de chupeta estimado foi 46,8%. Assim, fatores modificáveis foram identificados como de risco para interrupção do AME

HIV AND HCV COINFECTION: PREVALENCE, ASSOCIATED FACTORS AND GENOTYPE CHARACTERIZATION IN THE MIDWEST REGION OF BRAZIL

Estudo transversal sobre a prevalência, fatores associados e distribuição dos genótipos do HCV foi realizado em 848 pacientes infectados pelo HIV, recrutados em centros de referência na Região Centro-Oeste do Brasil. A taxa de prevalência de coinfecção HIV-HCV foi de 6,9% (IC 95%: 5,2-8,6). Na análise multivariada, o aumento da idade, o uso de drogas ilícitas (injetáveis e não injetáveis), história de transfusão de sangue antes de 1994, e ausência de companheiro constante foram fatores associados independentes e significativos para a coinfecção HIV-HCV. A análise filogenética baseada na região NS5B revelou a presença de dois principais genótipos do HCV em circulação: genótipos 1 (58,3%) e 3 (41,7%). A prevalência da coinfecção HIV-HCV foi menor do que as relatadas em estudos realizados com pacientes infectados pelo HIV em diferentes regiões do Brasil, devido ao fato de que o uso de drogas ilícitas não é modo frequente de transmissão do HIV neste Estado do Brasil. Triagem sorológica de pacientes HIV-positivos para HCV antes de iniciar o tratamento antirretroviral, identificação completa dos fatores associados e a implementação de programas eficazes de redução de danos são altamente recomendados para fornecer informações úteis, para o tratamento e para evitar a coinfecção com HCV nestes pacientes.A cross-sectional study on prevalence, associated factors and genotype distribution of HCV infection was conducted among 848 HIV-infected patients recruited at reference centers in the Midwest Region of Brazil. The prevalence rate of HIV-HCV coinfection was 6.9% (95% CI: 5.2 to 8.6). In multivariable analysis, increasing age, use of illicit drugs (injection and non-injection), a history of blood transfusion before 1994, and the absence of a steady partnership were significant independent associated factors for HIV-HCV coinfection. The phylogenetic analysis based on the NS5B region revealed the presence of two major circulating genotypes of HCV: genotypes 1 (58.3%) and 3 (41.7%). The prevalence of HIV-HCV coinfection was lower than those reported in studies conducted with HIV-infected patients in different regions of Brazil, due to the fact that illicit drug use is not a frequent mode of HIV transmission in this region of Brazil. Serologic screening of HIV-patients for HCV before initiating antiretroviral treatment, a comprehensive identification of associated factors, and the implementation of effective harm reduction programs are highly recommended to provide useful information for treatment and to prevent HCV coinfection in these patients

Control of papaya fruits anthracnose by essential oil of Ricinus communis

The aim of this work was to investigate the potential of castor oil for the control of papaya diseases caused by the fungus Colletotrichum gloeosporioides and the bacterium Pseudomonas caricapapayae. The treatment with 1% castor oil did not significantly affect the fungal growth. The effectiveness of castor oil for the control of anthracnose was shown when 5% and 10% (v/v) were used in the assays resulting in reduced mycelial growth. Fungal sporulation was strongly inhibited at 10% (v/v) concentration of essential oil. The studies with the fresh fruits treated with 5% (v/v) castor oil in aqueous emulsions resulted in effective reduction of pathogen spread in these fruits. No lesion was found in the fruits treated with oil, when compared to the control fruits. Castor oil showed no effect against the P. caricapapayae when tested in vitro. These results suggested the potential use of the castor bean essential oil and its fatty acids constituents for the control of anthracnose in papaya fruits