42 research outputs found

    Egg parasitoid wasps as natural enemies of the neotropical stink bug Dichelops melacanthus

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    O objetivo deste trabalho foi determinar o potencial de cinco espécies de vespas Scelionidae – Telenomus podisi, Trissolcus basalis, Trissolcus urichi, Trissolcus teretis e Trissolcus brochymenae –, como inimigos naturais do percevejo neotropical Dichelops melacanthus, e determinar se a presença de ovos de outras espécies de percevejo tem influência sobre o parasitismo e o desenvolvimento dos parasitoides. Foram realizados dois tipos de experimentos em laboratório: sem escolha de hospedeiros (ovos de D. melacanthus) e com escolha (ovos de D. melacanthus e de Euschistus heros). Foram registrados parâmetros biológicos que incluíram: proporção de parasitismo, sobrevivência de imaturos, razão sexual da progênie, tempo de desenvolvimento dos estágios imaturos e preferência de hospedeiro. Todas as espécies de parasitóides avaliadas podem parasitar e desenvolver-se em ovos de D. melacanthus. A escolha inicial de ovos não influenciou a proporção de ovos de D. melacanthus parasitados por Tr. basalis, Tr. teretis ou Tr. brochymenae. Entretanto, para Te. podisi e Tr. urichi, a escolha inicial por ovos de D. melacanthus aumentou em 9 e 14 vezes, respectivamente, a chance de parasitismo nesta espécie. Aspectos comportamentais e ecológicos dos inimigos naturais devem ser considerados antes de sua utilização em programas de controle biológico.The objective of this work was to determine the potential of five species of Scelionidae wasps – Telenomus podisi, Trissolcus basalis, Trissolcus urichi, Trissolcus teretis and Trissolcus brochymenae – as natural enemies of the neotropical stink bug Dichelops melacanthus, and to determine if the presence of eggs of other stink bug species influences the parasitism and development of the parasitoids. Two kinds of experiments were done in laboratory: without choice of hosts (eggs of D. melacanthus) and with choice (eggs of D. melacanthus and of Euschistus heros). Biological parameters, including proportion of parasitism, immature survivorship, progeny sex ratio, immature stage development period, and host preference were recorded. All the evaluated parasitoids can parasitize and develop on D. melacanthus eggs. The first choice of eggs did not influence the proportion of D. melacanthus eggs parasitized by Tr. basalis, Tr. teretis or Tr. brochymenae. However, D. melacanthus eggs as the first choice of Te. podisi and Tr. urichi increased, respectively, 9 and 14 times the chance for parasitism on eggs of this species. Behavioral and ecological aspects of parasitoids should be considered prior to their use in biological control programs

    Neutrophil elastase promotes Leishmania donovani infection via interferon-β

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    Visceral leishmaniasis is a deadly illness caused by Leishmania donovani that provokes liver and spleen inflammation and tissue destruction. In cutaneous leishmaniasis, the protein of L. major named inhibitor of serine peptidases (ISP2) inactivates neutrophil elastase (NE) present at the macrophage surface, resulting in blockade of TLR4 activation, prevention of TNF and IFN production and parasite survival. We report poor intracellular growth of L. donovani in macrophages from knock-out mice for NE (ela-/-), TLR4 or TLR2. NE and TLR4 co-localized with the parasite in the parasitophorous vacuole. Parasite load in the liver and spleen of ela-/- mice were reduced and accompanied by increased nitric oxide and decreased TGF production. Expression of ISP2 was not detected in L. donovani and a transgenic line constitutively expressing ISP2, displayed poor intracellular growth in macrophages and decreased burden in mice. Infected ela-/- macrophages displayed significantly lower IFN mRNA than background mice macrophages and the intracellular growth of was fully restored by exogenous IFN. We propose that L. donovani utilizes the host NE-TLR machinery to induce IFN necessary for parasite survival/growth during early infection. Low or absent expression of parasite ISP2 in L. donovani is necessary to preserve the activation of the NE-TLR pathway

    Evaluation of Depression, Anxiety and Sleep Quality in the Brazilian Population During Social Isolation Due to the New Coronavirus (SARS-CoV-2) pandemic: the DEGAS-CoV Study/ Avaliação da Depressão, Ansiedade e Qualidade do Sono na População Brasileira Durante o Isolamento Social Devido à Nova Pandemia do Coronavírus (SARS-CoV-2): o Estudo DEGAS-CoV

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    Introduction: The new coronavirus infection (COVID-19) has caused distress and repercussions in mental and physical health of individuals. Depression, anxiety and worsening of sleep quality have been reported in several recent articles that surveyed populations all over the globe. Our work meant to access, through a cross-sectional study, these disorders in the Brazilian population, through the application of an online questionnaire conducted on the second trimester of 2020. Materials and Methods: We applied an online questionnaire, filled with questions regarding social, economic, financial, educational and health status, as well as questions from the Hospital Anxiety and Depression Scale (HAD), and from the Pittsburgh Sleep Quality Index (PSQI).Results: We collected 2,695 valid answers, from April 24th to May 31st, 2020. Age ranged from 18 to 79 years, mean of 31.3. Women were 76.3%, men 23.7%. Symptoms of Anxiety were found in 56.5%, of depression in 46.1%, and of bad sleep in 49.2%. Some groups were more prone than others to one or more of those conditions, such as: younger people, women, mestizos, people with lesser years of education, of lower income or whose income dropped significantly during the pandemic, caregivers, students, sedentary or people practicing less physical activity, people who followed more hours of news of COVID-19 and those less engaged in social and instrumental activities.Conclusion: anxiety, depression and bad sleep quality were significantly high in our survey. Mental and sleep health is heterogeneously affected among individuals, depending on social, economic, financial, educational and health status

    Estratégias de uso de água salobra na produção de alface em hidroponia NFT Strategies for use of brackish water in NFT hydroponic lettuce production

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    Plantas de alface crespa 'Verônica' foram cultivadas em condições hidropônicas, objetivando avaliar três diferentes estratégias de emprego de águas salobras: 1) águas salobras para reposição das perdas por evapotranspiração (ETc) e água doce para o preparo da solução nutritiva (SN); 2) águas salobras para o preparo da SN e água doce para reposição da ETc; 3) águas salobras para o preparo da SN e reposição da ETc. Os níveis de salinidade da água foram obtidos pela adição de NaCl à água doce (0,27 dS m-1): 1,45; 2,51; 3,6; 5,41 e 7,5 dS m-1. O experimento foi conduzido em quatro blocos aleatorizados, com quatro repetições por tratamento. Uma estrutura de pesquisa foi construída com 72 parcelas que simulam a técnica do fluxo laminar de nutrientes (NFT). O uso de água salobra apenas para repor a ETc não produziu efeito sobre a produção da alface. Por outro lado, o uso de águas salobras para o preparo da SN e água doce para reposição da ETc, reduziu o rendimento da alface (massa de matéria fresca da parte aérea) em 4,99% por (dS m-1). O rendimento foi reduzido em 7% por dS m-1 quando águas salobras foram usadas tanto para o preparo da SN quanto para reposição da ETc. Apesar da redução linear da produção da alface com o aumento da salinidade da água, sintomas depreciativos para a qualidade da alface hidropônica não foram registrados.<br>Plants of crisphead lettuce cv. 'Verônica' were grown under hydroponic conditions aiming to evaluate three different strategies of brackish waters utilization: 1) brackish waters to replace the evapotranspiration loss (ETc) and fresh water to prepare nutrient solution (NS); 2) brackish waters to prepare NS and fresh water to replace the ETc; 3) brackish waters to prepare NS and replace ETc. The levels of water salinity were obtained by addition of NaCl to fresh water (0.27 dS m-1): 1.45; 2.51; 3.6; 5.41 and 7.5 dS m-1. The experiment was conducted in randomized blocks with four replications per treatment. A research structure was built with 72 experimental units which simulate the nutrient film technique (NFT). The use of brackish water only to replace the ETc did not affect the lettuce yield. On the other hand, the use of brackish waters to prepare NS, and fresh water to replace the ETc loss, reduce the lettuce yield (shoot fresh matter) by 4.99% per (dS m-1). The lettuce yield was reduced by 7% per dS m-1 as brackish water was used to prepare NS and replace ETc loss. Despite the linear decline of lettuce yield as the water salinity increased, depreciative symptoms for quality of hydroponic lettuce were not registered
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