61 research outputs found

    Comportamento e ecologia de fêmeas ingurgitadas do carrapato Boophilus microplus em pastagem de Brachiaria decumbens no Brasil

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    The Boophilus microplus tick poses great economic and cattle health problems that causes annual costs of one billion dollars in Brazil. The current study sought to investigate preoviposition stage of B. microplus in natural conditions. A total of 300 engorged female ticks were used, in each of the Winter of 1998 and the Summer of 1998/1999, at the Embrapa Gado de Leite, Juiz de Fora, MG, Brazil. On cloudy and humid days, engorged female traveled very little, while at temperatures of less than 15ºC and relative humidity of 95%, they were practically stationary. They did not travel at night or during rainfall. They traveled in a similar way in the Winter and in the Summer, laying almost the same amount of eggs (being 0.12 g and 0.11 g, respectively).O carrapato B. microplus possui grande importância econômico-sanitária, causando prejuízo anual de um bilhão de dólares no Brasil segundo o Ministério da Agricultura. Utilizou-se um total de 300 fêmeas ingurgitadas com seis repetições no inverno de 1998 e seis no verão de 1998/1999. A fêmea pode se deslocar desde o momento em que cai do hospedeiro até o início da oviposição, o que é influenciado pela luminosidade, temperatura e cobertura vegetal. Em dias nublados e úmidos, as fêmeas deslocam-se muito pouco, enquanto em temperaturas abaixo de 15ºC e com umidade de 95%, elas praticamente não se movem. Não se movem à noite ou com chuva e deslocam-se de maneira semelhante no inverno e no verão, produzindo quantidade de ovos também semelhantes (inverno: 0,12g e verão: 0,11g)

    Comportamento e ecologia de larvas do carrapato Boophilus microplus em pastagem de Brachiaria decumbens

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    Relatively little research has been carried out on the behavioral ecology of B. microplus larvae in pasture, this being the principal objective of the current work. Six releases were made in winter (June-August, 1998) and in summer (November-January, 1998/1999). The tick larvae were laboratory reared in 20 adapted plastic syringes. Its were opened and placed in pastures of Brachiaria decumbens, at the research center of the Embrapa Gado de Leite, in Juiz de Fora city, Minas Gerais estate, Brazil. The larvae were observed three times per day, three days per week. The time taken for the larvae to reach the extremities of the grass was mainly related to the air temperature. In summer, the larvae formed smaller and less active aggregations than in winter. This behavior was considered to be a mechanism to avoid overheating and increase ventilation to save energy. Their horizontal and vertical migrations were considered a behavioral strategy to avoid the direct rays of the sun.Existem relativamente poucos trabalhos sobre ecologia e comportamento das larvas de Boophilus microplus na pastagem, tendo sido este o principal objetivo do presente trabalho. Foram monitoradas seis repetições no inverno de 1998 e seis no verão de 1998/1999. As larvas foram acondicionadas em 20 seringas plásticas adaptadas e disponibilizadas em pasto constituído pela gramínea Brachiaria decumbens, na Embrapa Gado de Leite, em Juiz de Fora, estado de Minas Gerais, permitindo sua dispersão. Foram realizadas três observações diárias, três vezes por semana. Verificou-se que o tempo que as larvas levam para alcançar as extremidades da gramínea é condicionado principalmente pela temperatura. No verão, as larvas formam agrupamentos menores e menos ativos do que no inverno. Este comportamento sugere minimizar o superaquecimento e aumentar a ventilação, economizando energia. As migrações horizontal e vertical ocorrem como estratégia comportamental contra a ação direta dos raios solares

    Challenges of nematode control in ruminants : focus on Latin America

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    AbstractGastrointestinal nematodes (GIN) of ruminants (cattle, sheep and goats) are ubiquitous and can cause severe injuries to infected animals and significant losses in farming revenues. GIN are able to survive severe environmental and host conditions, but mankind has developed a number of ingenious methods for parasite control. The commerce and use of modern anthelmintic drugs with a broad spectrum of activity has been a solid tool for nearly 40 years, however the continuous use of these drugs, has led to the selection of populations of drug-resistant worms worldwide. At present, the ever-growing agricultural systems in Latin America are facing many challenges and cannot rely on the far-reaching objective of parasitic elimination from the host or the environment. The lack of extensive programs for monitoring drug resistance exacerbates the negative consequences of reduced efficacy, which is evident in some areas with the increase in mortality rate even after treatment. Experts agree that new schemes of parasitic control are needed and should be based on the strategy of targeted selective treatment where affected hosts are identified and treated accordingly. In this article, we will focus our discussion on the challenges for the control of GIN in Latin America by 2020 imposed by reduced drug efficacy. We will evaluate phenotypic and molecular markers, methods for single-animal evaluation, and the implementation of schemes for anthelmintic treatment that address parasites in refugia

    Atividade in vitro de extratos de Artemisia annua L (Asteraceae) sobre Rhipicephalus (Boophilus) microplus

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    The activity of plant extracts on parasites may indicate groups of substances that are potentially useful for controlling Rhipicephalus (Boophilus) microplus. The aim of the present study was to investigate the in vitro action of Artemisia annua extracts on this tick. The concentrations of the sesquiterpene lactones artemisinin and deoxyartemisinin present in plant extracts were quantified via high-performance liquid chromatography. Four extracts produced from the concentrated crude extract (CCE) were evaluated on larvae using the impregnated paper method, with readings after 24 hours of incubation. The engorged females were immersed in the CCE and in its four derived extracts for five minutes, with incubation for subsequent analysis of biological parameters. The extracts were not effective on the larvae at the concentrations tested (3.1 to 50 mg.mL-1). The CCE showed greater efficacy on engorged females (EC50 of 130.6 mg.mL-1 and EC90 of 302.9 mg.mL-1) than did the derived extracts. These results tend to confirm that the action of artemisinin on engorged females of R.(B.) microplus is conditional to their blood intake. In this case, in vitro methods would be inadequate for effective evaluation of the action of A. annua on R. (B.) microplus.A atividade de extratos vegetais sobre parasitas pode indicar grupos de substâncias de uso potencial no controle de Rhipicephalus (Boophilus) microplus. O objetivo do presente estudo foi investigar a ação in vitro de extratos de Artemisia annua sobre esta espécie. A concentração das lactonas sesquiterpênicas artemisinina e deoxiartemisinina presentes nos extratos vegetais, foi quantificada via cromatografia líquida de alta eficiência. Quatro extratos produzidos a partir do extrato bruto concentrado (EBC) foram avaliados sobre larvas pela metodologia do papel impregnado, com leitura após 24 horas de incubação. As fêmeas ingurgitadas foram imersas por cinco minutos no EBC e nos seus quatro extratos derivados, e incubadas para posterior análise dos parâmetros biológicos. Os extratos não tiveram eficácia sobre as larvas nas concentrações avaliadas (de 3,1 a 50 mg.mL-1). O EBC apresentou melhor eficácia sobre as fêmeas ingurgitadas (CE 50 de 130,6 mg.mL-1 e CE 90 de 302,9 mg.mL-1) que os extratos derivados. Esses resultados tendem a confirmar que a ação da artemisinina sobre as fêmeas ingurgitadas de R. (B.) microplus estaria condicionada à sua ingestão através do sangue. Nesse caso, os métodos in vitro seriam inadequados para a efetiva avaliação da ação de A. annua R.(B.) microplus.313

    Utilização das TDICs no processo de ensino-aprendizagem durante o ensino remoto emergencial no ambiente universitário

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    Buscou-se caracterizar as práticas pedagógicas utilizadas nos cursos de Licenciatura em Educação Física durante a pandemia de covid-19. Trata-se de um estudo descritivo com abordagem quantitativa realizado entre os meses de outubro de 2020 e julho de 2021. Os dados foram coletados via Google Formulários. A amostra foi composta por 27 professores de IES públicas e privadas. Os dados foram analisados por meio da estatística descritiva. Encontrou-se que o método de ensino mais utilizado foi o remoto. Encontrou-se as seguintes prevalências: métodos avaliativos - avaliações objetivas e os seminários; plataforma - Google Meet; dificuldades de docentes e estudantes - fácil dispersão dos alunos e a baixa qualidade da conexão da internet. Conclui-se que, apesar da imposição emergencial da utilização do meio virtual para o ensino e da falta de suporte financeiro, os professores se adaptaram às demandas de ensino remoto e apontam que o aprendizado gerado se faz significativo

    Living with the elderly is related to a better performance in the recognition of facial expressions of emotion among older individuals

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    Background: Cohabitation with the elderly may bring benefits to social relationships and exert an influence on the recognition of facial expressions of emotion. Objective: Compare emotion recognition skills between a cohabitation group (CHG) of older adults who live with a dependent elderly individual and a non-cohabitation group (NCHG) of older adults who do not live with an elderly individual. Methods: Interviews were conducted with 62 older adults in the CHG and 56 in the NCHG. The two groups were similar with regard to gender, age, schooling, degree of dependence, cognitive performance, and depressive symptoms. A dynamic task with six emotions (anger, disgust, happiness, surprise, sadness, and fear) and four levels of intensity was administered to evaluate the recognition of facial emotions. Results: The CHG performed better than the NCHG regarding the correct identification of emotions, specifically surprise (60%), disgust (60%, 80%, and 100%), fear (80%), and sadness (80% and 100%). Discussion: Cohabitation with an elderly individual seems to offer benefits to older adults in terms of recognizing facial expressions of emotion

    Efeito acaricida de óleos essenciais e concentrados emulsionáveis de Eucalyptus spp em Boophilus microplus

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    Biocide action of Eucalyptus citriodora, Eucalyptus globulus and Eucalyptus staigeriana were studied against Boophilus microplus tick, aiming the production of an environmentally and ecologically conect and len harmpol acaricide. Essential oil emulsion of three Eucaliptus species were tested in five different concentrations against larvae and engorged female of B. microplus. Oils were submitted to gas chromatograph coupled to mass spectrometer (GC/MS) analysis looking for its composition. Citronelal is the major component of E. citriodora essential oil, being responsible for its acaricide action. The same happens with 1.8-cineole in E. globulus. In E. staigeriana, there are many substances involved in a synergic action against B. microplus. E. citriodora essential oil killed all ticks in an average concentration of 17.5% as compared to E. globulus with 15% and E. staigeriana with 12.5%. E. globulus concentrated emulsion killed all ticks in an average concentration of 9.9% and E. staigeriana in a concentration of 3.9%. Further steps will be pursued to make those essential oils to be tested under field conditions and available to the farmers, since bioacaricides has commercial appeal, allowing B. microplus control in a less aggressive way to the environment.Realizou-se um estudo sobre a ação biocida de Eucalyptus citriodora, Eucalyptus globulus e Eucalyptus staigeriana no carrapato Boophilus microplus, buscando-se a produção de acaricidas menos agressivos ao meio ambiente. Os óleos essenciais das três espécies e os concentrados emulsionáveis de E. globulus e E. staigeriana foram testados em cinco concentrações diferentes contra larvas e fêmeas ingurgitadas de B. microplus. Os óleos foram submetidos à análise por cromatografia gasosa acoplada à espectrometria de massas (CG/EM), a fim de se investigar sua composição. O citronelal é o principal componente do óleo de E. citriodora, sendo responsável por sua ação acaricida. O mesmo ocorre com o 1,8-cineol em E. globulus. Em E. staigeriana existem várias substâncias que agem sinergicamente contra B. microplus. O óleo essencial de E. citriodora matou 100% dos carrapatos a uma concentração média de 17,5%, o de E. globulus a 15% e o de E. staigeriana a 12,5%. Os concentrados emulsionáveis de E. globulus mataram 100% dos carrapatos a uma concentração média de 9,9% e o de E. staigeriana a uma concentração de 3,9%. O desenvolvimento de produtos que possam ser testados a campo e comercializados a preços competitivos serão passos a serem seguidos. Os biocarrapaticidas têm um apelo comercial grande, permitindo controlar B. microplus de um modo menos agressivo ao meio ambiente

    In vitro and in vivo activity of a hypotoxic copper(I) complex against dermotropic Leishmania species

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    ABSTRACT Cutaneous leishmaniasis is a disease caused by protozoa of the genus Leishmania and, currently, the treatment of first choice is meglumine antimoniate. However, due to its limited effectiveness and high toxicity, it is necessary to seek new active principles for leishmaniasis treatment. Metal complexes are gaining importance due to their effectiveness and low toxicity. In this context, the present study aimed to evaluate the in vitro and in vivo antileishmanial activity of the hypotoxic copper(I) complex [HB(pz)3]Cu(PCN). Four dermotropic species of Leishmania were tested with the metal complex and its effectiveness was determined through parasitic viability and infectivity rate, and cytotoxicity was determined using a redox dye (resazurin). For the in vivo tests, hamsters were infected and the lesions treated with a formulated ointment containing the complex, the effectiveness of which was assessed by measuring the diameter of the inoculum/snout location and determining the parasitic load. The results demonstrated moderate toxicity in murine macrophages and human monocytes and better efficacy in Leishmania (V.) braziliensis when compared to the other species tested, with a 50% reduction in the viability of promastigote and amastigote forms (in vitro). General data from daily topical treatment for up to 30 days showed low efficacy for reducing lesions, and no clinical and parasitological cure was observed in the experimental animals. Thus, the [HB(pz)3]Cu(PCN) complex proved to be promising in in vitro studies against L. (V.) braziliensis, and should be further tested in new formulations and new experimental treatment schemes

    RISCOS ASSOCIADOS À COLONIZAÇÃO POR CANDIDA NA CAVIDADE ORAL DE ESCOLARES DA REDE MUNICIPAL DE GOVERNADOR MANGABEIRA-BA

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    O objetivo geral do estudo foi conhecer fatores de risco associados à colonização por Candida na cavidade oral de escolares da rede municipal de Governador Mangabeira-BA. Foi realizada a coleta de uma amostra do raspado superficial do dorso da língua com o auxilio de swab em cada escolar sendo semeada a levedura em meio de cultura cromogênico. Foram estudadas 252 crianças, sendo que 81 (32,14%) apresentaram Candida. A espécie mais prevalente foi Candida albicans, sendo observada em 48 (59,25%) das crianças avaliadas. Os resultados demonstraram associação estatística entre a idade, hábitos de higiene bucal e alimentação rica em doces e frituras com colonização da mucosa bucal das crianças pela levedura. Há necessidade da conscientização dos pais para motivar seus filhos a ter uma alimentação saudável, realizar acompanhamento com profissional odontólogo anualmente visando favorecer a saúde bucal e a redução da ocorrência de lesões por Candida

    In vitro culture of parasitic stages of Haemonchus contortus = Cultivo in vitro de estádios parasitários de Haemonchus contortus

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    Haemonchus contortus is a constraint to sheep production. Seeking to reduce the use of hosts and produce parasitic stages in large-scale, a 42-day in vitro culture protocol of H. contortus third-stage larvae was optimized using Dulbecco’s modified Eagle’s medium (DMEM). In cell-free culture, larvae were maintained at 39.6°C, in acidic media (pH 6.1) for 3 or 6 days with Δ4-dafachronic acid followed by DMEM pH 7.4 supplemented or not with Fildes’ reagent. In DMEM pH 7.4 at 37°C, supplementation with Caco-2 cells was compared to Fildes. On Day 14, fourth-stage larvae (L4) development rates in acidic media supplemented (86.8-88.4%) or not (74.4-77.8%) with Fildes and in Caco-2 cell co-culture (92.6%) were similar, and superior to DMEM pH 7.4 with Fildes (0.0%). On Day 21, Caco-2 cell co-culture resulted in higher larvae differentiation (25.0%) and lower degeneration (13.9%) compared to acidic media (1.5-8.1% and 48.6-69.9%, respectively). This is the first report of prolonged in vitro culture of H. contortus larvae using commercial media in co-culture with Caco-2 cells. Although no progression to the adult stage, Caco-2 cell co-culture resulted in morphological differentiation of H. contortus L4 and larval viability for up to 28 days
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