Os organoclorados constituem um dos principais grupos de poluentes que afetam os ecossistemas devido a sua grande persistência no ambiente e toxicidade para os organismos. A toninha, Pontoporia blainvillei, é um cetáceo costeiro, o único golfinho brasileiro considerado ameaçado de extinção por conta das atividades antrópicas. O objetivo desse trabalho foi avaliar a ocorrência de organoclorados em amostras de gordura subcutânea de indivíduos de Pontoporia blainvillei coletados na região costeira do Estado de São Paulo. A metodologia de extração e purificação das amostras foi testada e otimizada conforme procedimentos descritos na literatura. Foram realizadas as análises em 53 amostras de toninha (Pontoporia blainvillei): 29 machos e 24 fêmeas. Todas as concentrações de organoclorados apresentaram valores maiores nos machos, em comparação com as fêmeas de mesma maturidade. As concentrações dos compostos organoclorados nas toninhas do litoral paulista variaram, em ng.g-1 lipídios nos PCBs de 326 a 42.185, DDTs de 107 a 7.185, HCHs n.d. a 46, CHLs n.d. a 126, HCB < 2 a 133 e Mirex < 7 a 259. A razão DDTs/PCBs foi menor que 0,6 indicando uma maior contribuição industrial do que agrícola na área de estudo. Houve diferenças significativas dos valores dos OCs nas toninhas das localidades do litoral de São Paulo, com as maiores concentrações ocorrendo na Baixada Santista. / Organochlorines are one of the main pollutant groups that affect the ecosystems due to their environmental persistence and toxicity to the organisms. Franciscana dolphin, Pontoporia blainvillei, is a coastal cetacean, the only Brazilian dolphin considered threatened with extinction, due to the human activities. The aim of this work was evaluate the occurrence of organochlorines in the blubber samples of Pontoporia blainvillei collected on the coast of São Paulo State. The extraction and purification methodology was tested and optimized according to proceedings described in literature. A total of 53 individuals were analyzed: 29 males and 24 females. Organochlorine concentrations were higher in males when comparing to females with the same sexual maturity. PCBs were the predominant compounds (326 - 42185 ng g-1 lipid weight), followed by DDTs (107 - 7185 ng g-1 lipid wt), HCHs (n.d. - 46 ng g-1 lipid wt), CHLs (n.d. - 126 ng g-1 lipid wt), HCB (< 2 - 133 ng g-1 lipid wt) and Mirex (< 7 - 259 ng g-1 lipid wt). The ratio DDTs/PCBs was lesser than 0.6 indicating a major industrial than agricultural contribution in the study area. There were significant differences between the OCs values in franciscanas from 3 localities of São Paulo State coast: with the higher concentrations occurring in Baixada Santista.

De façon à maximiser leur valeur sélective, les individus doivent prendre différentes décisions qui doivent concorder aux conditions environnementales (se reproduire ou pas ? quand ? quel investissement parental ?). Ces décisions sont fortement influencées par la sécrétion de certaines hormones comme l’hormone lutéinisante (LH) déclencheur de la reproduction, l’hormone de stress (CORT) et la prolactine (PRL), pour l’expression des soins parentaux. Les contaminants chimiques et naturels sont omniprésents et ont même été retrouvés en zones polaires. De nombreux contaminants sont des perturbateurs endocriniens et pourraient altérer les décisions de reproduction, mais les preuves manquent pour la faune sauvage. Cette thèse vise donc à identifier les liens entre certains polluants organiques persistants dits ‘d’héritage’ (POPs : PCBs, pesticides organochlorés), le mercure (Hg) et les hormones LH, CORT et PRL chez plusieurs espèces d’oiseaux marins arctiques et antarctiques. Les résultats obtenus ont démontré que ces contaminants interagissent avec ces hormones, et de façon spécifique : le Hg réprimerait la sécrétion d’hormones hypophysaires (LH, PRL) tandis que les PCBs stimuleraient la production de CORT. Plus précisément, le Hg pourrait affecter la sécrétion de LH en réprimant l’apport de GnRH à l’hypophyse et les PCBs pourraient stimuler le nombre de récepteurs à l’ACTH au niveau des glandes surrénales. Le Hg et les PCBs peuvent donc altérer les décisions de reproduction et impacter la valeur sélective : des taux élevés de Hg sont associés à la suppression de la reproduction et à un moindre investissement parental, tandis que la présence de PCBs pourrait exacerber la susceptibilité au stress environnemental. Les conséquences à long terme de l’exposition des oiseaux marins à ces contaminants sont discutées dans le cadre des changements globaux qui affectent les pôles. / In order to maximise fitness, individuals will have to take several decisions that shall match with environmental conditions (whether to breed or not, when to breed, what level of parental investment). These decisions are mediated by hormones : such as luteinizing hormone (LH), a pituitary hormone involved in the onset of breeding, stress hormones (corticosterone, CORT) and prolactin (PRL) a pituitary hormone involved in the expression of parental care. Environmental contaminants are present world-wide, and also in Polar Regions. Since many contaminants are endocrine disruptors, they may impair breeding decisions, but evidences are scarce for wildlife. The aim of this thesis was to assess the relationships between some legacy persistent organic pollutants (POPs : PCBs, organochlorine pesticides), mercury (Hg) and hormones (LH, CORT, PRL) in different Arctic and Antarctic seabird species. Results show that POPs and Hg clearly interact with LH, CORT and PRL secretion. These contaminants appear to target different hormones : increasing Hg was related to decreasing pituitary hormone secretion (LH and PRL) ; whereas increasing PCBs were linked to an exacerbated CORT response to an acute stress. Hg disrupted LH secretion by probably suppressing GnRH input to the pituitary ; PCBs seem to act at the adrenal level by probably stimulating ACTH receptors. Legacy POPs and Hg are therefore able to disrupt reproductive decisions and to impact fitness : elevated Hg levels were linked to skipped reproduction and poor incubation behavior ; elevated PCB levels may make individuals more susceptible to environmental perturbations. The long-term consequences of contaminant exposure for seabirds are discussed in the context of the environmental challenges affecting polar regions.

Os poluentes orgânicos persistentes (POPs) são acumulados em tecidos gordurosos dos organismos vivos em concentrações relativamente altas em animais do topo da cadeia alimentar, como os golfinhos. Os objetivos deste trabalho foram avaliar a distribuição e acumulação de POPs em tecidos (gordura, fígado, rim e músculo) de toninhas (Pontoporia blainvillei) do litoral sul de São Paulo, bem como as diferenças/similaridades entre gênero e maturidade sexual e a transferência via placenta. Os valores de concentração mediana (ng g-1; peso úmido) para as 16 amostras de gordura, fígado, rim e músculo, respectivamente, foram: PCBs (987; 19,2; 5,08; 4,41); DDTs (550; 10,3; 2,67; 1,89); PBDEs (32,7; 0,230; 0,095; 0,050); Mirex (21,5; 0,457; 0,168; 0,083); HCB (15,4; <0,360; <0,360; <0,144); HCHs (<0,870; 2,20; <0,218; <0,087); Clordanas (<1,45; <0,362; <0,362; <0,145). Os machos jovens apresentaram as maiores concentrações dos POPs, seguidos pelos machos adultos, fêmeas jovens, fêmeas adultas e fetos. Foi observada transferência dos contaminantes das fêmeas gestantes para seus fetos entre 14 a 28% para PCBs e 19 a 45% para DDTs. A gordura apresentou correlação significativa com os demais tecidos estudados para acumulação dos PCBs, DDTs e PBDEs sugerindo a sua representatividade para estudos desses POPs em toninhas. / Persistent organic pollutants (POPs) are accumulated in fatty tissues of organisms in relatively high concentrations in animals in high position of the food chain such as dolphins. The aims of this study were to evaluate the distribution and accumulation of POPs in tissues (blubber, liver, kidney and muscle) of franciscana dolphin (Pontoporia blainvillei) collected on the southern coast of São Paulo as well as differences/similarities between genre and sexual maturity and the transplacental transfer. The values of median concentration (ng g-1; wet weight) for 16 samples of blubber, liver, kidney and muscle, respectively, were: PCBs (987; 19,2; 5,08; 4,41); DDTs (550; 10,3; 2,67; 1,89); PBDEs (32,7; 0,230; 0,095; 0,050); Mirex (21,5; 0,457; 0,168; 0,083); HCB (15,4; <0,360; <0,360; <0,144); HCHs (<0,870; 2,20; <0,218; <0,087); Chlordanes (<1,45; <0,362; <0,362; <0,145). POPs concentrations were higher in young males followed by adult males, young females, adult females and fetuses. Maternal transfer of POPs to the fetuses was between 14 to 28% for PCBs and 19 to 45% for DDTs. Blubber showed a significant correlation with the other tissues studied for PCBs, DDTs and PBDEs suggesting its representativeness for evaluation of these POPs in franciscana dolphin.

Diferentes abordagens teóricas têm sido utilizadas em estudos de sistemas biomoleculares com o objetivo de contribuir com o tratamento de diversas doenças. Para a dor neuropática, por exemplo, o estudo de compostos que interagem com o receptor sigma-1 (Sig-1R) pode elucidar os principais fatores associados à atividade biológica dos mesmos. Nesse propósito, estudos de Relações Quantitativas Estrutura-Atividade (QSAR) utilizando os métodos de regressão por Mínimos Quadrados Parciais (PLS) e Rede Neural Artificial (ANN) foram aplicados a 64 antagonistas do Sig-1R pertencentes à classe de 1-arilpirazóis. Modelos PLS e ANN foram utilizados com o objetivo de descrever comportamentos lineares e não lineares, respectivamente, entre um conjunto de descritores e a atividade biológica dos compostos selecionados. O modelo PLS foi obtido com 51 compostos no conjunto treinamento e 13 compostos no conjunto teste (r² = 0,768, q² = 0,684 e r²teste = 0,785). Testes de leave-N-out, randomização da atividade biológica e detecção de outliers confirmaram a robustez e estabilidade dos modelos e mostraram que os mesmos não foram obtidos por correlações ao acaso. Modelos também foram gerados a partir da Rede Neural Artificial Perceptron de Multicamadas (MLP-ANN), sendo que a arquitetura 6-12-1, treinada com as funções de transferência tansig-tansig, apresentou a melhor resposta para a predição da atividade biológica dos compostos (r²treinamento = 0,891, r²validação = 0,852 e r²teste = 0,793). Outra abordagem foi utilizada para simular o ambiente de membranas sinápticas utilizando bicamadas lipídicas compostas por POPC, DOPE, POPS e colesterol. Os estudos de dinâmica molecular desenvolvidos mostraram que altas concentrações de colesterol induzem redução da área por lipídeo e difusão lateral e aumento na espessura da membrana e nos valores de parâmetro de ordem causados pelo ordenamento das cadeias acil dos fosfolipídeos. As bicamadas lipídicas obtidas podem ser usadas para simular interações entre lipídeos e pequenas moléculas ou proteínas contribuindo para as pesquisas associadas a doenças como Alzheimer e Parkinson. As abordagens usadas nessa tese são essenciais para o desenvolvimento de novas pesquisas em Química Medicinal Computacional. / Different theoretical approaches have been used in the studies of biomolecular systems aiming to contribute with the treatment of several diseases. For neuropathic pain, for example, the study of compounds that interact with sigma-1 receptor (Sig-1R) can elucidate the main factors associated to their biological activities. For this purpose, studies of Quantitative Structure-Activity Relationships (QSAR) using Partial Least Squares (PLS) and Artificial Neural Network (ANN) methods were applied to 64 Sig-1R antagonists belong to 1-arylpyrazole class. PLS and ANN models were used in order to describe linear and nonlinear behavior, respectively, between a set of descriptors and the biological activity of the selected compounds. The PLS model was obtained with 51 compounds in the training set and 13 compounds in the test set (r² = 0.768, q² = 0.684 and r²test = 0.785). Leave-N-out tests, biological activity randomization and outliers detection confirmed the robustness and stability of the models and showed that they were not obtained by chance correlations. Models were also generated from Multilayer Perceptron Artificial Neural Network (MLP-ANN) and the 6-12-1 architecture, trained by tansig-tansig transfer functions, showed the best result for the biological activity prediction of the compounds (r²training = 0.891, r²validation = 0.852 and r²test = 0.793). Another approach was used to simulate synaptic membranes environment using lipid bilayers composed by POPC, DOPE, POPS and cholesterol. Performed molecular dynamics studies showed that high cholesterol concentration induces decrease of area per lipid and lateral diffusion and increase of membrane thickness and order parameter caused by ordering of phospholipids acil chains. The obtained lipid bilayers can be used to simulate interactions between lipids and small molecules or proteins contributing for researches associated to Alzheimer and Parkinson diseases. The approaches used in this thesis are essential for the development of new researches in Computational Medicinal Chemistry.

Os poluentes orgânicos persistentes (POPs) são acumulados em tecidos gordurosos dos organismos vivos em concentrações relativamente altas em animais do topo da cadeia alimentar, como os golfinhos. Os objetivos deste trabalho foram avaliar a distribuição e acumulação de POPs em tecidos (gordura, fígado, rim e músculo) de toninhas (Pontoporia blainvillei) do litoral sul de São Paulo, bem como as diferenças/similaridades entre gênero e maturidade sexual e a transferência via placenta. Os valores de concentração mediana (ng g-1; peso úmido) para as 16 amostras de gordura, fígado, rim e músculo, respectivamente, foram: PCBs (987; 19,2; 5,08; 4,41); DDTs (550; 10,3; 2,67; 1,89); PBDEs (32,7; 0,230; 0,095; 0,050); Mirex (21,5; 0,457; 0,168; 0,083); HCB (15,4; <0,360; <0,360; <0,144); HCHs (<0,870; 2,20; <0,218; <0,087); Clordanas (<1,45; <0,362; <0,362; <0,145). Os machos jovens apresentaram as maiores concentrações dos POPs, seguidos pelos machos adultos, fêmeas jovens, fêmeas adultas e fetos. Foi observada transferência dos contaminantes das fêmeas gestantes para seus fetos entre 14 a 28% para PCBs e 19 a 45% para DDTs. A gordura apresentou correlação significativa com os demais tecidos estudados para acumulação dos PCBs, DDTs e PBDEs sugerindo a sua representatividade para estudos desses POPs em toninhas. / Persistent organic pollutants (POPs) are accumulated in fatty tissues of organisms in relatively high concentrations in animals in high position of the food chain such as dolphins. The aims of this study were to evaluate the distribution and accumulation of POPs in tissues (blubber, liver, kidney and muscle) of franciscana dolphin (Pontoporia blainvillei) collected on the southern coast of São Paulo as well as differences/similarities between genre and sexual maturity and the transplacental transfer. The values of median concentration (ng g-1; wet weight) for 16 samples of blubber, liver, kidney and muscle, respectively, were: PCBs (987; 19,2; 5,08; 4,41); DDTs (550; 10,3; 2,67; 1,89); PBDEs (32,7; 0,230; 0,095; 0,050); Mirex (21,5; 0,457; 0,168; 0,083); HCB (15,4; <0,360; <0,360; <0,144); HCHs (<0,870; 2,20; <0,218; <0,087); Chlordanes (<1,45; <0,362; <0,362; <0,145). POPs concentrations were higher in young males followed by adult males, young females, adult females and fetuses. Maternal transfer of POPs to the fetuses was between 14 to 28% for PCBs and 19 to 45% for DDTs. Blubber showed a significant correlation with the other tissues studied for PCBs, DDTs and PBDEs suggesting its representativeness for evaluation of these POPs in franciscana dolphin.

Diferentes abordagens teóricas têm sido utilizadas em estudos de sistemas biomoleculares com o objetivo de contribuir com o tratamento de diversas doenças. Para a dor neuropática, por exemplo, o estudo de compostos que interagem com o receptor sigma-1 (Sig-1R) pode elucidar os principais fatores associados à atividade biológica dos mesmos. Nesse propósito, estudos de Relações Quantitativas Estrutura-Atividade (QSAR) utilizando os métodos de regressão por Mínimos Quadrados Parciais (PLS) e Rede Neural Artificial (ANN) foram aplicados a 64 antagonistas do Sig-1R pertencentes à classe de 1-arilpirazóis. Modelos PLS e ANN foram utilizados com o objetivo de descrever comportamentos lineares e não lineares, respectivamente, entre um conjunto de descritores e a atividade biológica dos compostos selecionados. O modelo PLS foi obtido com 51 compostos no conjunto treinamento e 13 compostos no conjunto teste (r² = 0,768, q² = 0,684 e r²teste = 0,785). Testes de leave-N-out, randomização da atividade biológica e detecção de outliers confirmaram a robustez e estabilidade dos modelos e mostraram que os mesmos não foram obtidos por correlações ao acaso. Modelos também foram gerados a partir da Rede Neural Artificial Perceptron de Multicamadas (MLP-ANN), sendo que a arquitetura 6-12-1, treinada com as funções de transferência tansig-tansig, apresentou a melhor resposta para a predição da atividade biológica dos compostos (r²treinamento = 0,891, r²validação = 0,852 e r²teste = 0,793). Outra abordagem foi utilizada para simular o ambiente de membranas sinápticas utilizando bicamadas lipídicas compostas por POPC, DOPE, POPS e colesterol. Os estudos de dinâmica molecular desenvolvidos mostraram que altas concentrações de colesterol induzem redução da área por lipídeo e difusão lateral e aumento na espessura da membrana e nos valores de parâmetro de ordem causados pelo ordenamento das cadeias acil dos fosfolipídeos. As bicamadas lipídicas obtidas podem ser usadas para simular interações entre lipídeos e pequenas moléculas ou proteínas contribuindo para as pesquisas associadas a doenças como Alzheimer e Parkinson. As abordagens usadas nessa tese são essenciais para o desenvolvimento de novas pesquisas em Química Medicinal Computacional. / Different theoretical approaches have been used in the studies of biomolecular systems aiming to contribute with the treatment of several diseases. For neuropathic pain, for example, the study of compounds that interact with sigma-1 receptor (Sig-1R) can elucidate the main factors associated to their biological activities. For this purpose, studies of Quantitative Structure-Activity Relationships (QSAR) using Partial Least Squares (PLS) and Artificial Neural Network (ANN) methods were applied to 64 Sig-1R antagonists belong to 1-arylpyrazole class. PLS and ANN models were used in order to describe linear and nonlinear behavior, respectively, between a set of descriptors and the biological activity of the selected compounds. The PLS model was obtained with 51 compounds in the training set and 13 compounds in the test set (r² = 0.768, q² = 0.684 and r²test = 0.785). Leave-N-out tests, biological activity randomization and outliers detection confirmed the robustness and stability of the models and showed that they were not obtained by chance correlations. Models were also generated from Multilayer Perceptron Artificial Neural Network (MLP-ANN) and the 6-12-1 architecture, trained by tansig-tansig transfer functions, showed the best result for the biological activity prediction of the compounds (r²training = 0.891, r²validation = 0.852 and r²test = 0.793). Another approach was used to simulate synaptic membranes environment using lipid bilayers composed by POPC, DOPE, POPS and cholesterol. Performed molecular dynamics studies showed that high cholesterol concentration induces decrease of area per lipid and lateral diffusion and increase of membrane thickness and order parameter caused by ordering of phospholipids acil chains. The obtained lipid bilayers can be used to simulate interactions between lipids and small molecules or proteins contributing for researches associated to Alzheimer and Parkinson diseases. The approaches used in this thesis are essential for the development of new researches in Computational Medicinal Chemistry.

Philosophiae Doctor - PhD / Persistent organic pollutants (POPs) are very tenacious wastewater contaminants with negative impact on the ecosystem. The two major sources of POPs are wastewater from textile industries and pharmaceutical industries. They are known for their recalcitrance and circumvention of nearly all the known wastewater treatment procedures. However, the wastewater treatment methods which applied advanced oxidation processes (AOPs) are documented for their successful remediation of POPs. AOPs are a group of water treatment technologies which is centered on the generation of OH radicals for the purpose of oxidizing recalcitrant organic contaminants content of wastewater to their inert end products. Circumvention of the reported demerits of AOPs such as low degradation efficiency, generation of toxic intermediates, massive sludge production, high energy expenditure and operational cost can be done through the application of the combined AOPs in the wastewater treatment procedure. The resultant mineralisation of the POPs content of wastewater is due to the synergistic effect of the OH radicals produced in the combined AOPs. Hydrodynamic cavitation is the application of the pressure variation in a liquid flowing through the venturi or orifice plates. This results in generation, growth, implosion and subsequent production of OH radicals in the liquid matrix. The generated OH radical in the jet loop hydrodynamic cavitation was applied as a form of advanced oxidation process in combination with hydrogen peroxide, iron (II) oxides or the synthesized green nano zero valent iron (gnZVI) for the treatment of simulated textile and pharmaceutical wastewater.

A distribuição espacial e o histórico deposicional de poluentes orgânicos persistentes (POPs) em sedimentos foram avaliados no ecossistema marino-estuarino da Ilha do Marajó, Pará. Os pesticidas predominantes nos sedimentos da camada superficial foram os HCHs (<0,04 e 0,90 ng g-1) e DDTs (<0,02 - 2,72 ng g-1), em peso seco. PCBs e PBDEs não foram detectados. HCHs predominaram no Estuário do Rio Paracauari indicando uso recente provavelmente relacionado à atividade madeireira. DDTs foram detectados na Praia do Pesqueiro e nos testemunhos sedimentares (<0,02 - 12,31 ng g-1 peso seco) do Mercado, Fazenda e Paracauari. Os valores máximos de DDT ocorreram entre 1982 e 2008 e são associados com campanhas de saúde púbica. Há uma redução gradativa até o presente que coincide com a substituição do DDT por piretróides. A razão &#931;DDDs / &#931;DDEs, predominantemente < 1, indicou a ocorrência de processos decomposicionais aeróbicos. No geral, as condições ambientais não favorecem o acúmulo de pesticidas nos sedimentos, sendo que os valores estão abaixo do limite provável para causar efeitos adversos exceto para HCHs no Estuário do Rio Paracauari. O presente trabalho estabeleceu a distribuição de POPs na Ilha do Marajó e poderá contribuir para o processo de gestão costeira e ambiental da região. / The spatial distribution and depositional history of persistent organic pollutants (POPs) in sediments were evaluated in marino-estuarine ecosystem of Marajó Island, Pará. The predominant pesticides in sediments of the surface layer were HCHs (<0.04 and 0, 90 ng g-1) and DDTS (<0.02 to 2.72 ng g-1) by dry weight. PCBs and PBDEs weren\'t detected. HCHs predominated in Paracauari Estuary indicating recent use probably related to logging. DDTs were detected in Praia do Pesqueiro and sediment cores (<0.02 to 12.31 ng g-1 dry weight) Mercado, Fazenda and Paracauari. Maximum levels of DDT residues occurred between 1982 and 2008 and are associated with pubic health campaigns. There is a gradual reduction up to the present which coincides with the substitution of the DDTs by pyrethroids. The ratio &#931;DDDs / &#931;DDEs predominantly < 1 indicated the occurrence of decomposicional processes under aerobic conditions. Overall, the environmental conditions do not favor the accumulation of pesticides in sediments, and the values are below the threshold likely to cause adverse effects except for HCHs in Paracauari Estuary. This work established the distribution of POPs in Marajó Island and could contribute to the process of coastal and environmental management in the region.

A distribuição espacial e o histórico deposicional de poluentes orgânicos persistentes (POPs) em sedimentos foram avaliados no ecossistema marino-estuarino da Ilha do Marajó, Pará. Os pesticidas predominantes nos sedimentos da camada superficial foram os HCHs (<0,04 e 0,90 ng g-1) e DDTs (<0,02 - 2,72 ng g-1), em peso seco. PCBs e PBDEs não foram detectados. HCHs predominaram no Estuário do Rio Paracauari indicando uso recente provavelmente relacionado à atividade madeireira. DDTs foram detectados na Praia do Pesqueiro e nos testemunhos sedimentares (<0,02 - 12,31 ng g-1 peso seco) do Mercado, Fazenda e Paracauari. Os valores máximos de DDT ocorreram entre 1982 e 2008 e são associados com campanhas de saúde púbica. Há uma redução gradativa até o presente que coincide com a substituição do DDT por piretróides. A razão &#931;DDDs / &#931;DDEs, predominantemente < 1, indicou a ocorrência de processos decomposicionais aeróbicos. No geral, as condições ambientais não favorecem o acúmulo de pesticidas nos sedimentos, sendo que os valores estão abaixo do limite provável para causar efeitos adversos exceto para HCHs no Estuário do Rio Paracauari. O presente trabalho estabeleceu a distribuição de POPs na Ilha do Marajó e poderá contribuir para o processo de gestão costeira e ambiental da região. / The spatial distribution and depositional history of persistent organic pollutants (POPs) in sediments were evaluated in marino-estuarine ecosystem of Marajó Island, Pará. The predominant pesticides in sediments of the surface layer were HCHs (<0.04 and 0, 90 ng g-1) and DDTS (<0.02 to 2.72 ng g-1) by dry weight. PCBs and PBDEs weren\'t detected. HCHs predominated in Paracauari Estuary indicating recent use probably related to logging. DDTs were detected in Praia do Pesqueiro and sediment cores (<0.02 to 12.31 ng g-1 dry weight) Mercado, Fazenda and Paracauari. Maximum levels of DDT residues occurred between 1982 and 2008 and are associated with pubic health campaigns. There is a gradual reduction up to the present which coincides with the substitution of the DDTs by pyrethroids. The ratio &#931;DDDs / &#931;DDEs predominantly < 1 indicated the occurrence of decomposicional processes under aerobic conditions. Overall, the environmental conditions do not favor the accumulation of pesticides in sediments, and the values are below the threshold likely to cause adverse effects except for HCHs in Paracauari Estuary. This work established the distribution of POPs in Marajó Island and could contribute to the process of coastal and environmental management in the region.

Negative public perceptions toward law enforcement officers (LEOs) have increased in recent years as the result of police shootings of unarmed men. Researchers have focused on urban residents' perceptions toward LEOs, but have not examined the perceptions of rural residents. The purpose of this quantitative study was to examine the relationship between the dependent variable (DV) of rural citizens' perceptions toward LEOs and the independent variables (IVs) of age, gender, ethnicity, religion, marital status, sexual orientation, income, employment status, educational attainment, and immigration status. The social judgment theory and the primary socialization theory were used as the theoretical foundations to determine how the IVs affected the DV. A sample of 282 residents from southeastern Colorado completed the Perceptions of Police Scale and a demographics questionnaire. Multiple linear regressions were conducted to examine the relationship between the DV and the IVs. Results indicated that as educational attainment increased, perceptions toward LEOs increased. Residents had a positive perception toward LEOs on a number of scale items: Residents agreed that the police were helpful, provided safety, and protected them. Findings may be used to develop interventions to improve relationships between LEOs and residents living in rural areas who continue to have negative perceptions of the police.