Genetically modified cotton (Gossypium hirsutum L.) acreage has increased dramatically over the last six years. Reports of variable results in fiber quality and yield have arisen in these cultivars. Some changes in production practices have occurred coincident with the introduction of transgenic technology, such as reduced use of broad-spectrum insecticides, including organophosphates (OP) that could potentially influence the growth and yield of cotton. One factor that might affect these parameters is the difference in the amount of foliarly-applied phosphorus (P) between an OP and non-phosphate (NP) insecticide regime. Therefore, a study was conducted to investigate selected growth characteristics, yield, and fiber quality of genetically modified and conventional cotton as influenced by OP and foliar phosphorus (FP) applications. A four replication strip-plot experimental design was utilized with cultivar serving as the whole plot and insecticide regime as the sub-plot. Three cultivars of the same recurrent parent (ST4892BR, ST4793R, and ST474) were planted in 2001 and 2002 under irrigated conditions in Burleson County, TX on a Weswood silty clay loam (fine-silty, mixed, thermic Fluventic Ustochrept). The insecticide regime consisted of NP, NP+FP, and OP treatments. The FP was applied at P2O5 weight equivalent to the P component in the concurrent OP application. ST4892BR had greater lint yield than ST4793R and ST474. The yield increase can be explained through plant mapping analysis which showed ST4892BR producing larger bolls and greater boll numbers. In addition, evaluation of fruiting distribution showed ST4892BR contained more lint on sympodial branches 6 through 10. The insecticide regime effect on lint yield resulted in higher yield (P=0.08) for the NP+FP regime. Examination of yield components revealed NP+FP increased second position bolls, predominantly at sympodial branches 6 through 10. Leaf tissue analysis revealed increased levels of P for the OP and NP+FP over that of the NP insecticide regime, which indicates a potential for plants to acquire P from OP insecticides. Furthermore, the considerable yield response to small amounts of FP is not clearly understood. While conclusive evidence exists regarding cultivar yield differences, this study does not provide sufficient evidence to conclude that OP insecticides influence growth, yield, or fiber quality characteristics of these cotton cultivars.

Genetically modified cotton (Gossypium hirsutum L.) acreage has increased dramatically over the last six years. Reports of variable results in fiber quality and yield have arisen in these cultivars. Some changes in production practices have occurred coincident with the introduction of transgenic technology, such as reduced use of broad-spectrum insecticides, including organophosphates (OP) that could potentially influence the growth and yield of cotton. One factor that might affect these parameters is the difference in the amount of foliarly-applied phosphorus (P) between an OP and non-phosphate (NP) insecticide regime. Therefore, a study was conducted to investigate selected growth characteristics, yield, and fiber quality of genetically modified and conventional cotton as influenced by OP and foliar phosphorus (FP) applications. A four replication strip-plot experimental design was utilized with cultivar serving as the whole plot and insecticide regime as the sub-plot. Three cultivars of the same recurrent parent (ST4892BR, ST4793R, and ST474) were planted in 2001 and 2002 under irrigated conditions in Burleson County, TX on a Weswood silty clay loam (fine-silty, mixed, thermic Fluventic Ustochrept). The insecticide regime consisted of NP, NP+FP, and OP treatments. The FP was applied at P2O5 weight equivalent to the P component in the concurrent OP application. ST4892BR had greater lint yield than ST4793R and ST474. The yield increase can be explained through plant mapping analysis which showed ST4892BR producing larger bolls and greater boll numbers. In addition, evaluation of fruiting distribution showed ST4892BR contained more lint on sympodial branches 6 through 10. The insecticide regime effect on lint yield resulted in higher yield (P=0.08) for the NP+FP regime. Examination of yield components revealed NP+FP increased second position bolls, predominantly at sympodial branches 6 through 10. Leaf tissue analysis revealed increased levels of P for the OP and NP+FP over that of the NP insecticide regime, which indicates a potential for plants to acquire P from OP insecticides. Furthermore, the considerable yield response to small amounts of FP is not clearly understood. While conclusive evidence exists regarding cultivar yield differences, this study does not provide sufficient evidence to conclude that OP insecticides influence growth, yield, or fiber quality characteristics of these cotton cultivars.

No description available.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

Background: The effect of Malaria attack on maternal and child health in Nigeria is high compared with other countries in sub Saharan Africa. This problem has been a persistent issue in Nigeria and many researchers have tried to proffer solutions. Insecticide treated nets (ITN) have been identified as providing approximately 80% protection against malaria attack. However, all the measures put in place to control malaria failed to meet up with the set target of the Roll Back Malaria Initiative, which aimed at reducing malaria deaths in Nigeria by half by 2010 in line with the Millennium Development Goals (Anyaehie et al., 2009). As part of the global initiative to reduce malaria deaths before 2015 (Amoran, Senbanjo and Asagwara, 2011) the Nigerian government introduced intervention programmes to protect pregnant women, and children under-five years of age (Anyaehie et al., 2011). However, although there has been considerable and effective intervention in controlling this preventable disease in the African continent, marked inconsistency in the distribution of the ITN, scarcity and low usage in Nigeria (Amoran, Senbanjo and Asagwara, 2011) are apparent, despite emphasis on community-based strategies for malaria control (Obinna, 2011). For midwives in rural Nigeria the disproportionate vulnerability of pregnant women and young children is of great concern. This particular issue is the focus of a hermeneutic phenomenological inquiry into the experiences of pregnant women and mothers in their efforts to protect their families and themselves from malaria attack. The study contends that the ‘big (pan-African/national) story’ of malaria has found many voices, speaking from a predominantly positivist perspective. While some more interpretivist approaches to exploring experience have been employed elsewhere in Sub-Saharan Africa (Rachel and Frank 2005), there remains a need for more participatory research related to health care issues in Nigeria (Abdullahi et al 2013). Women and children make up the majority of the Nigeria population of over 160 million. An attack of malaria on them affects entire households and the economy of the nation. Therefore, the purpose of this study was to give voice to the ‘small (household) stories’ of Nigerian women (mothers and health workers), living and working in impoverished rural communities, and consider how their viewpoints, perspectives and imaginings might contribute to the fight for a malaria-free Nigeria. Methodological approach: The research draws on the philosophy of Martin Heidegger, Hans-Georg Gadamer, and Maurice Merleau-Ponty. The participants’ accounts are interpreted in terms of Africana ‘Womanism’ as defined by Hudson-Weems (1993), the socio-narratology approach elaborated by Frank (2010), and Igbo world-view. Research procedure: Individual semi-structured interviews and focus groups were conducted with Igbo women in three rural communities in Enugu State in eastern Nigeria (Nsukka, Ngwo, and Amechi). This was a three-phase process involving an initial orientation visit to engage with local gatekeepers and community health workers. A first round of interviews and discussion took place in three communities in 2014, followed by the first phase of interpretation. A second field trip took place in 2015, during which participants discussed the ongoing interpretation and elaborated further on some of the issues raised. Interpretive phases 2 and 3 followed this visit. Interpretive process: Interpretive shifts in understanding were accomplished in three ways: 1. Seeking thematic connections between participants’ accounts of living with the threat of malaria. 2. Engaging in dialogical narrative analysis to explore the work done by the stories embedded in individual accounts of living under the threat of malaria. 3. Crafting found poetry from within the collective accounts to produce an evocative text that could mediate an emotional response and understanding of the malaria experience. Key outcomes: The research was a response to calls for more participatory research into the detailed experiences of people in Africa facing up to the threat of malaria. It has provided a vehicle for the voices of a group of Nigerian women and health workers to bring attention to the continuing plight of pregnant women and their families with limited access to insecticide-treated bed nets in poor living conditions. They have told how they seek to empower themselves in their own small and particular ways. It has provided insights into their worldview(s) and what others might see from where they stand. As such it has added to their own call expressed during the research to “Keep malaria on the agenda.” The research has used the women’s own testimony to create an oral resource designed https://youtu.be/XelMXLUzTV0 to facilitate education and action among small local groups of women and their families, and for health workers in local rural communities.

Bean weevil, Zabrotes subfasciatus (Boheman, 1833) (Coleoptera: Chrysomelidae) is considered the main insect-pest of the stored beans. Currently its control is achieved through protective spray (fumigations). New techniques of alternative control are being used to minimize the use of insecticides such as the use of resistant cultivars and insecticide plants through powders, extracts and oils. This work was divided into four chapters. The first consisted of a review of literature. In the second evaluated the method of control through the use of powders plants of different parts of plants from three species of the genus Annona, seeds powders of Piper nigrum L. and plaster. In the third it has developed a method of control through the use of powders plants of different parts of plants from three species of the genus Annona; powder seeds of Piper nigrum L.; Ageratum conyzoides L. (branch and leaf); Ricinus communis L. (leaf) and Azadirachta indica A. juss associated with plaster. And the fourth was tested after four species of plants: Piper nigrum L., Chenopodium ambrosioides, Coriandrum sativum L. and Cymbopogon citratus (DC) Stapf and plaster. All experiments were conducted aiming to observe possible adverse effects of these materials on the Z. subfasciatus. In general, two couples of newly emerged adults, Z. subfasciatus were placed in plastic pots of 250 mL. Where in the second chapter was used 10 g of beans, mixed with 1 g of the powder of each anonácea (leaves and branches, individually), the black pepper powder and plaster. The third chapter 10 g of beans, mixed with 0.5 g of powder of each treatment and 0.5 g of plaster, thereby completing 1 g of different powders of plants associated with plaster. In the forth chapter 5 g of the bean group Rio, at concentrations of 0.5, 0.25; 0125 g of powder per container. Were evaluated in the second chapter: cumulative mortality of first-eighth day, oviposition in the thirteenth day and quantity of emergence holes in the eighth fortieth day after the installation of bioassays. In the third chapter: cumulative mortality of first-ninth day (alternate days), oviposition on the fifteenth day, number of emergence holes in fortieth seventh day, after the installation of the bioassays, and the fourth chapter: mortality, oviposition, emergency in 2º generation of adults, number of beans with eggs deposited on the surface by adults emerged and repellency of Z. subfasciatus. In the second chapter more effective treatments were the powder of black pepper, causing rapid death in adults and consequently lower numbers of eggs and emergence holes in the grains. In the third chapter was the most effective treatment the powder of the black pepper, causing rapid death in adults and also interfered in oviposition and the number of holes for emergencies of insects. And in the last chapter found that the powder of P. nigrum L. and C. ambrosioides showed highly toxic effect on adults of Z. subfasciatus causing 100% of death until the 5º day, not providing fertile eggs in grain treated with these materials, the emergence of adults impossible to Z. subfasciatus in the three concentrations were tested and repellents for adults, the concentration of 0.25 g / 5 g beans. The peak of oviposition occurred at 4 and 5 days after the emergence of adults of Z. subfasciatus. For the other powder, did not interfere in the variables analyzed, because the treatment did not differ statistically witness except in the variable repellency of Z. subfasciatus, because based on the Index of Preference of the powder C.citratuswa srepellent. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O caruncho-do-feijão, Zabrotes subfasciatus (Boheman, 1833) (Coleoptera: Chrysomelidae) é considerado o principal inseto-praga dos grãos de feijão armazenado. Atualmente seu controle é realizado através de pulverização protetora (fumigações). Novas técnicas de controle alternativo vêm sendo utilizadas para minimizar o uso de inseticidas, como a utilização de cultivares resistentes e plantas inseticidas por meio de pós, extratos e óleos. Esse trabalho foi dividido em quatro capítulos. O primeiro constituiu-se de uma revisão de literatura. No segundo avaliou-se o método de controle através da utilização de pós vegetais de diferentes partes de plantas de três espécies do gênero Annona, do pó das sementes de Piper nigrum L. e do gesso. No terceiro desenvolveu-se um método de controle através da utilização de pós vegetais de diferentes partes de plantas de três espécies do gênero Annona; do pó das sementes de Piper nigrum L.; Ageratum conyzoides L. (ramo e folha); Ricinus communis L. (folha) e Azadirachta indica A. juss associados ao gesso. E no quarto foram testados pós de quatro espécies vegetais: Piper nigrum L., Chenopodium ambrosioides, Coriandrum sativum L. e Cymbopogon citratus (DC.) Stapf e do gesso. Todos os experimentos foram realizados visando observar possíveis efeitos adversos desses materiais sobre Z. subfasciatus. Em geral, dois casais de adultos recém-emergidos, de Z. subfasciatus foram colocados em potes plásticos de 250 mL. Onde no segundo capítulo foi utilizado 10 g de feijão, homogeneizado com 1 g dos pós de cada anonácea (folhas e ramos, individualmente), pó da pimenta-do-reino e gesso. No terceiro capítulo 10 g de feijão, homogeneizado com 0,5 g dos pós de cada tratamento e 0,5 g de gesso, completando-se assim 1 g de diferentes pós-vegetais associados ao gesso. No quarto capítulo 5 g de feijão do grupo carioca, nas concentrações de 0,5; 0,25; 0,125 g de pó por recipiente. Foram avaliados no segundo capítulo: mortalidade acumulada do primeiro ao oitavo dia, oviposição no décimo terceiro dia e quantidade de orifícios de emergência no quadragésimo oitavo dia. No terceiro capítulo: mortalidade acumulada do primeiro ao nono dia (dias alternados), oviposição no décimo quinto dia, número de orifícios de emergência no quadragésimo sétimo dia; e no quarto capítulo: mortalidade, oviposição, emergência na 2ª geração de adultos, número de feijão com ovos depositados em sua superfície por adultos emergidos e repelência de Z. subfasciatus. No segundo capítulo os tratamentos mais eficazes foram os pós de pimenta-do-reino, que causou rápida mortalidade em adultos e conseqüentemente menor números de ovos e de orifícios de emergência nos grãos. No terceiro capítulo o tratamento mais eficaz foi o pó de pimenta-do-reino, que causou excelente mortalidade em adultos e também interferiu na oviposição e no número de orifícios de emergências dos insetos. E no ultimo capítulo verificou-se que os pós de P. nigrum L. e C. ambrosioides apresentaram efeito altamente tóxico aos adultos de Z. subfasciatus causando 100% de mortalidade até o 5º dia, não proporcionando ovos férteis nos grãos tratados com estes materiais, impossibilitaram a emergência dos adultos de Z. subfasciatus nas três concentrações testadas e foram repelentes aos adultos, na concentração 0,25 g / 5 g de feijão. O pico de oviposição ocorreu no 4º e 5º dias após a emergência de adultos de Z. subfasciatus. No caso dos outros pós, não interferiram nas variáveis analisadas, pois não diferiram estatisticamente do tratamento testemunha com exceção na variável repelência de Z. subfasciatus, pois com base no Índice de Preferência o pó do C. citratus foi repelente.

Made available in DSpace on 2015-03-26T13:30:26Z (GMT). No. of bitstreams: 1 texto completo.pdf: 467059 bytes, checksum: 1d1a81846871a147cd18c0da3b09de6d (MD5) Previous issue date: 2009-07-20 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The deltamethrin can be selective to natural enemies, and for the predator Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) is important in controlling pests in agricultural systems and forestry. The objective was to evaluate the effect of selective insecticide deltamethrin applied manually to leaves of eucalyptus in concentrations corresponding to 50%, 100% and 200% of the recommended dose for control of defoliating caterpillars of eucalypt in development, reproduction and morphology of fat body, digestive system and reproductive and midgut of the predator in the laboratory. The duration of the fourth stage, weight of males, post-oviposition and hatching of eggs were stimulated by different concentrations of the insecticide deltamethrin, highlighting the phenomenon of hormesis. Histology of the fat body, midgut and reproductive organs of insects subjected to different concentrations of the insecticide did not show variations. The combination of chemical and biological methods may be more durable if the selectivity of insecticides is recognized and exploited. / A deltametrina pode ser seletiva a inimigos naturais, como para o predador Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) que é importante no controle de pragas em sistemas agrícolas e florestais. O objetivo foi avaliar o efeito do inseticida seletivo deltametrina aplicado manualmente em folhas de eucalipto, em concentrações que correspondem a 50%, 100% e 200% da dose recomendada para o controle de lagartas desfolhadoras de eucalipto no desenvolvimento, reprodução e morfologia do corpo gorduroso, aparelho digestório e reprodutivos e intestino médio desse predador em laboratório. A duração do quarto estádio, o peso de machos, períodos de pós-oviposição e incubação dos ovos foram estimulados pelas diferentes concentrações do inseticida deltametrina, evidenciando o fenômeno de hormese. A histologia do corpo gorduroso, intestino médio e órgãos reprodutores dos insetos submetidos às diferentes concentrações do inseticida não apresentaram variações. A associação dos métodos químicos e biológicos pode ter maior durabilidade se a seletividade dos inseticidas for reconhecida e explorada.

Made available in DSpace on 2014-06-11T19:32:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-07Bitstream added on 2014-06-13T20:42:36Z : No. of bitstreams: 1 scomparin_alx_dr_jabo.pdf: 5977037 bytes, checksum: 8ab4f778519f1e5f248fa28ab2c97182 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A maioria dos organismos vivos são ectotérmicos, com exceção de pássaros e mamíferos. A temperatura corporal (Tc) de um ectotérmico é resultado da troca de calor entre o organismo e o meio ambiente e esta afeta a maioria das funções biológicas. Por exemplo, os insetos, para mudarem de estágio de desenvolvimento, requerem um mínimo de energia acumulada (calor). Para as pragas, a maioria dos modelos fenológicos é baseada na relação entre características do de desenvolvimento (ex., crescimento) e a temperatura do ar. Todavia, a utilização destes modelos ainda é limitada em razão da falta de exatidão na estimativa das temperaturas máximas e mínimas de desenvolvimento para a maioria das pragas. O objetivo deste trabalho foi avaliar a importância dos fatores: resistência a inseticidas e termoperíodo, assim como discutir os métodos de modelagem para o inseto endofítico Cydia pomonella. Para tal, se submeteu larvas e pupas de 4 linhagens diferentes desta espécie: sensível (Sv), resistente a diflubenzuron (Rdfb), resistente a deltametrina (Rdelta) e resistente ao granulovírus (Rgv), a 4 termoperíodos (15°C-20°C, 20°C-25°C, 25°C-30°C e 30°C- 35°C). Os parâmetros avaliados foram: taxa de crescimento, mortalidade, razão sexual e temperatura base, mínima e ótima de desenvolvimento do inseto. Com o auxílio dos valores obtidos nestes parâmetros, modelos lineares e curvilineares foram desenvolvidos, comparados entre si e com modelos obtidos por autores a temperaturas constantes. Os resultados mostraram que em condições de temperaturas variáveis a resistência implica em mudanças nos parâmetros biológicos (taxa de crescimento, mortalidade e razão sexual) e que o termoperíodo acelera o crescimento de larvas e pupas de carpocapsa. Com o auxílio dos modelos obtidos, foi realizada uma simulação do período de desenvolvimento de C. pomonella utilizando... / The majority living organisms are ectotherms except birds and mammals. The body temperature (Tb) of an ectotherm results from the energy balance between this the organisms and its environment. The Tb determines most of the biological functions. For instance, a minimum of heat accumulation by insects is needed to pass from a development stage to another during their life cycle. For insect pests, most of phenological models are based on life history trait (e.g., growth) and air temperature. Unfortunately, the use of phenological models is limited since there is a lack of accuracy estimatives in maximum and minimum temperatures. The aim this work was to study the importance of two factors ((i) the insecticide resistance, (ii) the thermoperiod) and the modelling methods to design a phenological model for the the endophyte insect Cydia pomonella. Four strains of C. pomonella: (i) Sv (susceptible strain), (ii) Rdfb (resistant to diflubenzuron), (iii) RD (resistant to deltamethrin), RGv (resistant to C. pomonella granulovirus) and 4 thermoperiods (15°C-20°C, 20°C-25°C, 25°C-30°C e 30°C-35°C) were used. Measured parameters were the development rate, the mortality, the sex ratio, the Toptm, Tmin and Tmax of the development rate. Based on the obtained values for each parameter, linear and curvilinear phenological models were made and compared between them and with those obtained at constant temperature by some authors. Thus, in fluctuating thermal conditions, it was shown that insecticide resistance involved aftereffects on life-history traits as the development rate, the mortality and sex ratio. Also, it was shown that the C. pomonella development rate at larval stage is higher in thermoperiodic conditions. With the models the development of C. pomonella was simulated using air and micro-habitat temperatures for two areas of apple orchards in Europe (e.g., Valais in Switzerland and la Drôme...(Complete abstract click electronic access below)

Made available in DSpace on 2016-06-02T20:20:37Z (GMT). No. of bitstreams: 1 6528.pdf: 3561839 bytes, checksum: c8340fc080cc021ff8bd4c57267b5ad6 (MD5) Previous issue date: 2014-11-05 / Universidade Federal de Minas Gerais / Currently, in Brazil, there has been noticed increases of agrochemicals use, in spite the trend of using less toxic products. Pyrethroids appear as the option due to low toxicity displayed to birds and mammals, and the low bioaccumulation along the trophic chain. The pyrethroid insecticide λ-cyhalothrin (LCH) is used against a variety of arthropods. These chemicals can reach aquatic environments either by direct application in fish farms to kill parasites or by runoff after agricultural and domestic use, then affecting non-target organisms. We dealt with evaluation of antioxidant responses of matrinxã, Brycon amazonicus, exposed to LCH (TrincaCaps® DVA) and its recovery, since this is a freshwater fish relevantly farmed in Brazil. Twelve fish (n=12) were exposed to 0.65 μgL-1 (10% of the LC50;96h) for 96 hours and allowed to recover in a xenobiotic free water for 7 days. Hematological, osmoregulatory, antioxidant, neurotoxic, histologic and genotoxic effects were evaluated after sub-lethal exposure and recovery. LCH was extremely toxic to B. amazonicus since the LC50;96h was below 0.1 mgL-1. After the exposure span, fish exhibited impairment of respiratory functions and hypovolemia; the hematological parameters were not completely reestablished, despite a tendency to recover. The osmotic balance was affected after exposure, and it was not completely restored after recovery. The activity of brain acetylcholinesterase did not depict any change after both evaluation periods. Antioxidant defenses were activated in liver, kidney and gills, but this fact was not enough to prevent lipid peroxidation. After recovery, some defenses remained activated; nevertheless no lipid peroxidation was observed in any tissue. Histological parameters indicated liver and kidney injury, but no one was observed in gills. The kidney morphology was severely affected, but was reestablished after recovery; an opposite response was observed in liver. Micronuclei and nuclear alterations in erythrocytes were not observed after either exposure or recovery. We call attention to the hepatotoxic and nephrotoxic potential of LCH in B. amazonicus, emphasizing the importance of substantial studies to ground its use regulations in agriculture and aquaculture activities, since the set of injuries observed poses risk to this fish species. / Atualmente, no Brasil o uso de agroquímicos é cada vez maior, sendo que há uma tendência à utilização de produtos considerados menos tóxicos. Por não se acumularem na cadeia trófica e apresentarem baixa toxicidade para aves e mamíferos, os piretroides sintéticos são uma alternativa ao uso de inseticidas persistentes no meio ambiente. A λ-cialotrina (LCH) é um inseticida piretroide utilizado no controle de amplo espectro de artrópodes. Tendo em vista a contaminação por LCH de ambientes aquáticos quer pelo uso doméstico, agrícola ou mesmo de forma irregular por piscicultores, faz-se necessário o estudo deste piretroide tanto quanto à sua toxicidade como quanto aos efeitos sobre os parâmetros bioquímico-metabólicos de espécies aquáticas, entre elas o matrinxã (Brycon amazonicus). O matrinxã é uma espécie neotropical originária da Bacia Amazônica, e das mais representativas na aquicultura brasileira. Com esse propósito, doze exemplares de B. amazonicus (n=12) foram expostos a uma concentração sub-letal (0,65 μgL-1, 10% da CL50;96h) de LCH (TrincaCaps® DVA), por 96 horas e recuperados por 7 dias em água livre desse xenobiotico. Foram avaliados os efeitos hematológicos, osmorregulatórios, antioxidantes, neurotóxicos, histológicos e genotóxicos da LCH após os períodos experimentais. A LCH mostrou-se extremamente tóxica para B. amazonicus, visto a CL50;96h menor que 0,1 mgL-1. Após a exposição, os peixes exibiram resposta indicativa de hipovolemia e danos aos processos respiratórios. Após a recuperação, os parâmetros estudados não se restabeleceram completamente, mas exibiram tendência à recuperação. O equilíbrio osmótico foi afetado após a exposição, não sendo totalmente recomposto após a recuperação. A atividade de acetilcolinesterase cerebral não se mostrou diferente em nenhum dos tempos avaliados. Observou-se modificações nas defesas antioxidantes hepática, renal e branquial, as quais não foram suficientes para evitar a peroxidação lipídica. Após a recuperação, algumas defesas permaneceram ativadas, porém não foi observada peroxidação lipídica em nenhum dos tecidos. A avaliação histológica mostrou danos hepáticos e renais, entretanto, não houve danos branquiais. O tecido renal foi severamente afetado, sendo a morfologia renal restabelecida após a recuperação, contrariamente ao observado no tecido hepático. A formação de micronúcleos e as alterações nucleares eritrocitárias não foram significativamente diferentes em nenhum dos tempos avaliados. As respostas obtidas nesse estudo mostram o potencial hepatotóxico e nefrotóxico da LCH ao B. amazonicus, ressaltando a importância de estudos que fundamentem a criação de legislações adequadas ao uso deste inseticida em agricultura e piscicultura, posto que as modificações observadas podem promover prejuízos às populações naturais dessa espécie.

Orientador: Geraldo Papa / Banca: Sérgio Luis de Carvalho / Banca: Luiz Roberto Pimentel Trevizan / Resumo: A exposição dérmica de amostradores foi avaliada na reentrada em lavoura de algodão após pulverização com o inseticida deltametrina. Aos 3 minutos após a aplicação quatro pessoas vestiram um conjunto de roupas (calça, camisa e luvas), entrando e permanecendo na área tratada por 30 minutos, simulando uma amostragem de pragas. O procedimento foi repetido aos 60 e 300 minutos e aos 1, 3, e 7 dias após a aplicação. Partes do tecido, correspondentes ao local de contato com várias partes do corpo, foram recortadas e analisadas quanto à quantidade de resíduos presentes. O inseticida foi extraído das roupas com acetato de etila e a determinação quantitativa foi feita por cromatografia gasosa. As exposições foram extrapoladas para uma jornada de trabalho de oito horas. Para classificar a segurança das condições de trabalho foram estimadas a margem de segurança (MS), dose tóxica (%DT/dia), dose tolerável dérmica e o tempo de trabalho seguro. O conjunto correspondente aos antebraços/braços/mãos concentrou 61,27% dos resíduos presentes na roupa. Partes correspondentes ao peitoral, pernas, coxas e costas alcançaram 13,40; 9,33; 9,32; e 6,65% dos resíduos totais encontrados nas roupas, respectivamente. Pela análise dos dados constatou-se que o intervalo de reentrada estabelecido para o produto comercial Decis 25 CE (deltametrina) que é de 24 h está superestimado. / Abstract: The objective of this work was to study the dermal exposure of workers to residues of the deltamethrin, applied in cotton. After 3 minutes of application four people dressed a group with cotton clothes (pant, shirt and gloves), entered and stayed in the treated area by 30 minutes, simulating a sampling. The procedure was repeated after 60 and 300 minutes and 1, 3, and 7 days of the application. The clothes were cut and put in plastic bags, and stored cold at -18º until analyses was performed. The analytical method consisted on the extraction of deltamethrin residues with a ethyl acetate and the quantitative determination was done by gas chromatograph. Exposure was extrapolated to a work day of 8 hours. To evaluate safety's conditions at work was estimated the Working Condition Unsafe (margin of safety - MOS <1), Poisonous Dose (%PD/day), Dermal Dose Tolerable and the estimate of Safe Work Duration (SWD). The corresponding group for the forearms/arms/hands concentrated 61.27% of present residues in the clothes. The residues found on the clothes, chest, legs, lame and back, were 13.40, 9.33, 9.32, and 6.65%, respectively. Results of deltamethrins amounts trapped on cotton clothes showed that 24h as a reentry interval for Decis 25 EC is overestimated. / Mestre