La transformation du rôle de l'État à l'égard des crises bancaires dans l'Union européenne et au Brésil

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

Evaluation of Motor Changes and Toxicity of Insecticides Fipronil and Imidacloprid in Africanized Honey Bees (Hymenoptera: Apidae)

Honey bees are important pollinators and are essential in beekeeping. Honey bees get exposed to systemic pesticides while foraging in contaminated fields, and it is important to know the toxicity (LD50) and evaluate the impacts of bees’ exposure to these molecules. Fipronil and imidacloprid are systemic pesticides widely used in Brazil and other countries. The objective of this study was to determine the LD50 (24 hours) and evaluate motor changes in Africanized honey bee foragers exposed to lethal and sublethal doses of fipronil and imidacloprid. To determine the LD50, foraging honey bees were exposed by ingestion and contact to five doses of fipronil (Regent 800WG®) and imidacloprid (Appalus 200SC®) insecticides. After 24 hours of exposure, the number of dead bees was counted, and the results were subjected to probit analysis. The motor activity of bees exposed by ingestion or contact to LD50 and sublethal doses (1/500th of the LD50) of both pesticides was assessed 4 hours after exposure using a behavioral observation box. The ingestion and contact with LD50 of fipronil were 0.0528±0.0090 and 0.0054±0.0041 μg/bee, respectively; the ingestion and contact with LD50 of imidacloprid were 0.0809±0.0135 and 0.0626±0.0080 μg/bee, respectively. Bees exposed to lethal and sublethal doses of both insecticides experienced significant motor alterations compared to the control, except for exposure to sublethal doses of fipronil by contact. Fipronil and imidacloprid are highly toxic and promote motor changes in bees. Thus, it is important to establish management methods to reduce pollinators’ exposure to these pesticides

Apitoxin harvest affects population development but not the hygienic behavior of African-derived honey bees

The biological properties of apitoxin have prompted its production for use in human and animal health applications. However, the apitoxin harvest triggers a defense reaction in honeybee colonies, which includes the release of alarm pheromones (isopentyl acetate and 2-heptanone), which cause stress and could cause behavioral changes that influence the routine activities of the colony. Considering the lack of data in the literature describing the effects of the prolonged harvesting of apitoxin, the present study conducted over a period of one year, aimed to investigate whether the apitoxin harvest influences population development and hygienic behavior of African-derived Apis mellifera (L.). We observed that apitoxin harvest affected the uncapped brood area of the colonies during the months of April, May, and June, and affected the capped brood area in July. The hygienic behavior of the colonies was not affected. Furthermore, we observed that during the study year, there was loss by abandonment of nine of the colonies subjected to apitoxin harvesting. We conclude that under the conditions of this study, the apitoxin harvest can negatively influence the development of the colony population during certain times of the year, without affecting the hygienic behavior of the colonies

Produtos naturais para o controle do ácaro Varroa destructor em abelhas africanizadas

The objective of this work was to evaluate the effects of oxalic acid and essential oils of plants on the control of Varroa destructor infestation in Africanized Apis mellifera colonies. The experiment was carried out in a completely randomized design, in 30 colonies, with six treatments and five replicates. Beehives were treated with essential oils of common rue (Ruta graveolens), eucalyptus (Eucalyptus spp.), and mint (Mentha piperita), besides thymol, oxalic acid, and a control treatment without product application. Varroa mite mortality levels, bee offspring mortality rate, and the varroa mite infestation rate in offspring and adult bees were evaluated before and after the application of each product. Oxalic acid and oils of common rue, thymol, eucalyptus and mint reduced significantly the mortality of offspring parasitized by this mite in 92.1, 83.3, 81.7, 86.4, and 81.3%, respectively. The treatment with oxalic acid also reduced varroa mite infestation in adult bees in 87.4%. The use of these products is efficient in reducing the mortality of A. mellifera offspring parasitized by V. destructor.O objetivo deste trabalho foi avaliar os efeitos do ácido oxálico e de óleos essenciais de plantas no controle da infestação pelo ácaro Varroa destructor em colônias de Apis mellifera africanizadas. O experimento foi realizado em delineamento inteiramente casualizado, em 30 colônias, com seis tratamentos e cinco repetições. As colmeias foram tratadas com óleos essenciais de arruda (Ruta graveolens), eucalipto (Eucalyptus spp.) e hortelã (Mentha piperita), além de timol, ácido oxálico e do tratamento controle sem aplicação de produtos. Foram avaliadas a mortalidade de varroas e as taxas de mortalidade de crias e de infestação de varroas em crias e em abelhas adultas, antes e depois da aplicação de cada produto. O ácido oxálico e os óleos de arruda, timol, eucalipto e de hortelã reduziram a mortalidade de crias parasitadas pelo ácaro em 92,1, 83,3, 81,7, 86,4 e 81,3%, respectivamente. O tratamento com ácido oxálico reduziu em 87,4% a infestação de varroas em abelhas adultas. O uso desses produtos é eficiente na redução da mortalidade de crias de A. mellifera parasitadas por V. destructor

ENSINO DE LÍNGUA ESTRANGEIRA NO CURSO DE SECRETARIADO EXECUTIVO BILÍNGUE: BUSCANDO UM CAMINHO PARA AS ANÁLISES DE NECESSIDADES ESPECÍFICAS

The present work aims to establish a new approach to teaching plans in a foreign language that considers the needs of students of the Bilingual Executive Secretary. This study was conducted in a large private university in southeastern Brazil. The research methods were used to analyze the experience reports, systematic observation of teaching plans for teachers of foreign language and some interviews with professionals from the Executive Secretary Bilingual. To support the literature about the theme, this research had the reading of authors that discuss about the teaching of foreign language and its characteristics, needs analysis of language learning for specific purposes, in this case, the demands of working in the field of a Executive Secretary. As main results we have been ideological discussions of teaching practice to teaching in a Marxist perspective. Such discussions may be considered the beginnings of an action research which is still begining and may raise numerous questions over the redesign based on the analysis of the data studied by the teachers involved. Furthermore, we noticed that to ensure that teaching work could give students access to what is not repetitive in social life, we must doubt some concepts developed by researchers of foreign language related to the subjective and objective needs, cause the homogeneity of needs is very questionable, since one can not predict the type of company management the student will work as well as the social practice that dictates the production of texts and the relation of their activities.O presente trabalho tem o objetivo de estabelecer uma abordagem para novos planos de ensino em língua estrangeira que leve em conta as necessidades dos alunos do Curso de Secretariado Executivo Bilíngue. Esse estudo foi realizado em uma grande universidade particular do sudeste do Brasil. Os métodos de pesquisa utilizados foram a análise dos relatos de experiência, a observação sistemática de planos de ensino de docentes de língua estrangeira e um trabalho de campo com entrevistas com profissionais da área de Secretariado Executivo Bilíngue. Para suporte à realização de uma revisão bibliográfica tivemos como referencial teórico autores que discutem o ensino de língua estrangeira pesquisando as características, análises de necessidades de aprendizagem de língua para fins específicos, no caso em pauta, as necessidades do atuante na área de Secretariado Executivo. Como principais resultados tivemos discussões ideológicas que foram da prática docente ao trabalho docente numa perspectiva marxista. Tais discussões podem ser consideradas o embrião de uma pesquisa-ação que ainda está em andamento e que poderá suscitar inúmeros questionamentos ao longo dos replanejamentos com base na análise dos dados estudados pelos docentes envolvidos. Adicionalmente, pudemos observar que para que o trabalho docente garanta aos alunos acesso ao que não é reiterativo na vida social, devemos por em cheque os conceitos desenvolvidos por estudiosos de língua estrangeira com relação à necessidade subjetiva e objetiva, uma vez que a homogeneidade de necessidades é algo muito discutível, pois não se consegue prever qual será modelo de gestão da empresa onde esse aluno trabalhará, bem como a prática social que dita a produção de textos e o âmbito de sua atuação

Effect of Protein Supplementation in the Bee Apis mellifera L. Exposed to the Agrochemical Fipronil

Inadequate quantity and quality of proteins in honey bee diet can cause weakening of their colonies and damage their resistance to agrochemical contamination, such as fipronil, which is highly toxic to bees. Thus, we tested the hypothesis if protein supplementation would improve longevity and locomotion of honeybees exposed to fipronil pesticide. Colonies of Apis mellifera Africanized were distributed into Control Group without protein supplementation and Supplemented Group with 25% crude protein provided as a paste form at 100 g per week. After four weeks, frames with sealed brood were removed and kept in an incubator until the emergence of worker bees, which were marked, returned to their hives and recaptured six days later to measure protein concentration in the hemolymph. The bee population development was measured by evaluating frames containing the queen’s oviposition from each colony. Also, nursing bees were recaptured exposed by contact to fipronil LD50% (0.009 ± 0.003 μg/bee), and the longevity and motor activity were measured. The results showed that the bee swarms protein supplementation promoted a significant increase in the sealed brood area. However, it did not promote changes in the protein content of the hemolymph. Protein supplementation of bee swarms did not influence the survival of bees exposed to fipronil in the locomotion tests; however, fipronil was toxic to bees and promoted changes in the locomotion of bees

Colony Transport Affects the Expression of Some Genes Related to the Apis mellifera L. Immune System

Migratory beekeeping can harm the bee colonies if not executed properly. Here, colonies of Apis mellifera were transported (for one or two hours) or not, following proper technical standards. To analyze gene expression (defensin-1, abaecin, and HSP70), forager bees were collected immediately, 24, and 72 hours after transportation. Bee mortality and population growth were measured before and after transportation. This study concludes that transporting honey bee colonies for 2 hours promotes immune system gene expression, although there are no significant changes in bee mortality and population growth of the colonies

Natural Products can Efficiently Control the Greater Wax Moth (Lepidoptera: Pyralidae), but are Harmless to Honey Bees

Honey bees (Apis mellifera L.) have great global socioeconomic and environmental importance. However, the greater wax moth (Galleria mellonella L.) is a pest that causes serious worldwide damage to honey bee colonies. Good beekeeping practices and physical, chemical, or natural methods can be used to control wax moths. The use of natural products is a more sustainable option because of their lower toxicity to the environment and the colony. Therefore, we evaluated the efficiency of four natural products for greater wax moth control: neem oil (Azadirachta indica), eucalyptus oil (Eucalyptus spp.), tobacco extract (Nicotiana tabacum), and malagueta pepper extract (Capsicum frutescens). We also evaluated their effects on adult bees and on the population growth of colonies. The 4th instar wax moths and adult bees were subjected to in vitro bioassays of different concentrations of the products. The results allowed usto establish a concentration for each product that was safe for the bees and effectively controlled the moth. Then, we sprayed them on bee colonies to evaluate their effects on population growth. The neem and eucalyptus oils caused wax moth mortality at low concentrations, but did not affect colony population growth. However, they did have a toxic effect on adult bees. The tobacco and pepper extracts efficiently controlled the moth, but did not cause adult bee mortality or interfered with the population growth of the colonies. Therefore, the tobacco and pepper extracts could efficiently control the greater wax moth, without damaging honey bees

Comparative study of two commercially pure titanium casting methods

The interest in using titanium to fabricate removable partial denture (RPD) frameworks has increased, but there are few studies evaluating the effects of casting methods on clasp behavior. OBJECTIVE: This study compared the occurrence of porosities and the retentive force of commercially pure titanium (CP Ti) and cobalt-chromium (Co-Cr) removable partial denture circumferential clasps cast by induction/centrifugation and plasma/vacuum-pressure. MATERIAL AND METHODS: 72 frameworks were cast from CP Ti (n=36) and Co-Cr alloy (n=36; control group). For each material, 18 frameworks were casted by electromagnetic induction and injected by centrifugation, whereas the other 18 were casted by plasma and injected by vacuum-pressure. For each casting method, three subgroups (n=6) were formed: 0.25 mm, 0.50 mm, and 0.75 mm undercuts. The specimens were radiographed and subjected to an insertion/removal test simulating 5 years of framework use. Data were analyzed by ANOVA and Tukey's to compare materials and cast methods (α=0.05). RESULTS: Three of 18 specimens of the induction/centrifugation group and 9 of 18 specimens of plasma/vacuum-pressure cast presented porosities, but only 1 and 7 specimens, respectively, were rejected for simulation test. For Co-Cr alloy, no defects were found. Comparing the casting methods, statistically significant differences (

Toxic Metals in the Crude Propolis and Its Transfer Rate to the Ethanolic Extract

Concentrations of six toxic metals (Ni, Cr, Hg, Cd, Pb and Sn) in 106 samples of Brazilian crude propolis and the transfer rate of these contaminants to ethanolic extract of propolis were evaluated by atomic absorption spectrophotometry. The results show the presence of all the analyzed metals in the samples of crude propolis of São Paulo and Minas Gerais States. Regarding the transfer of these metals to ethanolic extract of propolis, a significant reduction was observed for all metals analyzed. The crude propolis can be considered as an indicator of toxic metals in the environment and the reduction observed in the ethanolic extract of propolis makes the product safe for consumption