Northeastern Region Of Brazil Research Articles

Irrigation Depth and Carnauba (Copernicia prunifera) Straw Increase Water Use Efficiency in the Cherry Tomato in a Semi-Arid Region

This research addresses irrigation strategies for saving water, including the use of irrigation depths of 50, 75, 100, 125 and 150% of the crop evapotranspiration (ETc) and a ground cover of carnauba straw, in evaluating the response of the cherry tomato (Solanum lycopersicum var cerasiforme L) submitted to different levels of water availability in soil with and without ground cover, in the semi-arid region of northeastern Brazil. The physiological components showed higher values under ground cover and when submitted to 100% ETc. The greatest number of total and commercial fruit was obtained when the soil was covered, and irrigated with depths of 75 and 100%. Carnauba straw with irrigation depths of 100 and 125% resulted in the greatest fresh fruit weight. The highest values for fruit diameter and length were achieved in the soil under cover. Maximum productivity, 11,404.20 kg ha-1, was obtained at 107.5%, while for the soil with no ground cover, maximum productivity was 7,778.86 kg ha-1, obtained with an irrigation depth of 140%. Based on the results, soil productivity is possible without a cover of carnauba straw, at an irrigation depth of 50.5%, which can generate savings of 3400 m³ water-cycle-1 ha-1. In addition, water use efficiency in the cherry tomato was 3.06 kg m-3 and 1.95 kg m-3, with and without ground cover respectively. It can be concluded that the use of carnauba straw makes it possible to reduce water consumption in the 'red' cherry tomato under conditions of water scarcity.

Crescimento e fluorescência de alfazema submetida ao osmocondicionamento das sementes e à salinidade

A alfazema é uma espécie medicinal amplamente utilizada na medicina popular, especialmente na região Nordeste do Brasil. Contudo, seu crescimento pode ser limitado pelo excesso de sais na água utilizada na irrigação, sendo necessária a busca por alternativas que minimizem os efeitos. Assim, objetivou-se avaliar o condicionamento osmótico das sementes nas características de crescimento e fluorescência da clorofila ‘a’ em plantas de M. suaveolens sob estresse salino. O delineamento estatístico foi o de blocos casualizados em esquema fatorial incompleto 5x5 com cinco níveis de condutividade elétrica da água de irrigação (0,5; 1,45; 5,00; 8,55; e 10,0 dS m-1) e cinco potenciais osmóticos (0,0; -0,15; -0,50; -0,85; e -1,0 MPa), com quatro repetições constituídas de duas plantas, totalizando nove combinações geradas através da matriz Composto Central de Box. Foram avaliadas as características de crescimento e os parâmetros de fluorescência da clorofila ‘a’ aos 45 dias após o início da aplicação das águas salinas. Os dados foram submetidos aos testes de normalidade (Shapiro-Wilk) e de homogeneidade das variâncias (Bartlett). Após os dados terem atendido aos pressupostos, os mesmos foram submetidos à análise de variância pelo teste F, nos casos de significância foi realizada análise de regressão polinomial. As características de crescimento foram afetadas severamente pelo aumento da salinidade da água de irrigação. Salinidade acima de 3,9 dS m-1 reduz todos os parâmetros de fluorescência da clorofila a em plantas de alfazema brava. O osmocodicionamento das sementes com polietilenoglicol atenua os efeitos negativos da salinidade sobre a emissão de folhas. O condicionamento das sementes com PEG estimula a atividade dos índices de fluorescência da clorofila ‘a’.

Evolução e perspectivas do setor eólico no Brasil: análise dos principais estados produtores

Este artigo propõe analisar a evolução do setor eólico no Brasil, resgatando as políticas públicas de incentivo ao setor, e apresentar tendências para o futuro, destacando a participação dos Estados brasileiros na produção e comercialização da energia eólica. Foi proposto um campo empírico de análise com base em investigação das regiões de maior expressividade produtiva, com uma abordagem qualitativa aos moldes descritivos, perfazendo o campo de uma predição de tendência para o setor. Dados os destaques aos programas governamentais que incentivaram o avanço da energia eólica e aos mecanismos de compra de energia por meio de leilões, observou-se que a região Nordeste, especificamente os Estados do Rio Grande do Norte e a Bahia, concentra a maior parte dos parques eólicos e capacidade instalada. Isso se deve aos incentivos públicos dotados no setor, associados às condições climáticas das regiões e às correntes de ventos. A tendência observada pode ser atribuída de diversas possibilidades, que se somada tanto a fatores endógenos quanto exógenos, ou seja, estímulos estrangeiros em ampliação do uso pela energia limpa com fatores climáticos e econômicos internos no país, este último amparado por apoios governamentais, tornará a fonte predominante no fornecimento de energia elétrica por fontes limpas e renováveis, capaz de reestruturar no longo prazo a cadeia consumidora pela sua amplitude comercial a preços acessíveis e tecnologias de produção e distribuição a um curso disruptivo.

Lower Cretaceous non-marine ostracods of the Orós Formation, Iguatu basin: Taxonomy and biostratigraphic considerations

Non-marine ostracods have been used for a long time to aid in the understanding of the Lower Cretaceous sedimentary deposits of Brazil, with various studies showing their value for biostratigraphic zonation in different basins. The northeastern region of Brazil contains several basins south of the Potiguar Basin which originated from the rifting that resulted from the opening of the Atlantic Ocean, and thus contain an important record of the Cretaceous Period. This paper has the objective of studying the ostracods recovered from two adjacent sections (Transnordestina A and Transnordestina B) belonging to the Orós Formation, Iguatu Basin, Ceará, Brazil, detailing their taxonomy and developing biostratigraphic inferences based on the observed fauna. A total of 19 species were found in the analyzed samples, distributed among 11 genera and five families: Cypridea hystricoides, Cypridea paraibensis, Cypridea cf. C. clavata, Cypridea punctacentralis sp. nov., Brasacypris ovum, Pattersoncypris sinuata, Pattersoncypris cf. P. sinuata, Pattersoncypris? sp., Ilyocypris? arca sp. nov., Ilyocypris? latanodi sp. nov., Rhinocypris? ericius sp. nov., Pythagoracypris latavectis gen. et sp. nov., Hastacypris adamantem gen. et sp. nov., Looneyellopsis mvili, Musacchiocythere plastica, Musacchiocythere? sp., Alicenula leguminella, Alicenula cf. D. oblonga, and an incertae sedis species. From the recovered species, a Hauterivian–Aptian interval can be inferred for the studied sections.

Respostas da qualidade da água e fitoplânctons à redução de vazão e recepção de cargas de sedimentos no reservatório de Xingó/AL

In the semi-arid region of northeastern Brazil, the Xingo reservoir is the last of a series of cascading reservoirs in the Sao Francisco river basin. From the perspective of river flow, the sharp reduction of rainfall in 2012 promoted the program of average flow reduction from 2013, contextualized by the most severe reduction in flow over the last hundred years. In 2015 a bottom discharge was given to the Delmiro Gouveia reservoir for the Xingo reservoir, raising concern about the effects of these actions on the water quality of this reservoir. Given the complexity of water quality variations in aquatic ecosystems, it is necessary to expand the panorama of physical and chemical responses of reservoir waters inserted in cascade systems. This article aims to evaluate the effects of average flow reduction, in the period from 2010 to 2015 of the Sao Francisco River basin, and of bottom discharge on the quality of Xingo reservoir water, also used for human supply. For this purpose, secondary data on rainfall, flow and water quality were collected by CHESF at three monitoring points on the Lake, representative of the anterior, intermediate and posterior parts. The results showed that the event of flow reduction allied to upstream sediment discharge led to an increase in temperature and alteration in nutrient concentration with consequent proliferation of cyanobacteria.

Facial Injuries and the Gender Issue: Expressions of Violence in a Metropolitan Region of Northeastern Brazil.

The aims of this investigation were to describe the profile of men and women victims of violence and identify factors associated with the severity of facial trauma. A retrospective study was carried out from 762 records of victims attended at the Institute of Legal Medicine and Dentistry located in a metropolitan region of Northeastern Brazil. The dependent variable was type of facial trauma suffered by victims. Independent variables were the sociodemographic characteristics of victims, characteristics of aggressors and circumstances of violence. Descriptive, bivariate (c2 test) and multivariate statistics were made through logistic regression. Level of significance was set at p < 0.05. The mean age of victims was 29.78 years (SD=13.33). Based on the final regression model, male subjects [odds ratio (OR)=2.22, 95% CI=1.08-4.57, p=0.030], assaulted by other male subjects (OR=4.88; 95% CI=1.12-21.26; p=0.035) through instrument (OR=6.67; 95% CI=2.85-15.60; p<0,001) or mixed aggressions (OR=4.34; 95% CI=1.44-13.02; p=0.009) were more likely to exhibit facial bone fractures or dentoalveolar fractures. The findings highlight that men and women present important victimization differentials in relation to interpersonal violence and facial trauma. Victim's gender, aggressor's gender and mechanism of aggression may exert influence on facial trauma patterns.

In silico functional prediction of hypothetical proteins from the core genome of Corynebacterium pseudotuberculosis biovar ovis.

Corynebacterium pseudotuberculosis is a pathogen of veterinary relevance diseases, being divided into two biovars: equi and ovis; causing ulcerative lymphangitis and caseous lymphadenitis, respectively. The isolation and sequencing of C. pseudotuberculosis biovar ovis strains in the Northern and Northeastern regions of Brazil exhibited the emergence of this pathogen, which causes economic losses to small ruminant producers, and condemnation of carcasses and skins of animals. Through the pan-genomic approach, it is possible to determine and analyze genes that are shared by all strains of a species—the core genome. However, many of these genes do not have any predicted function, being characterized as hypothetical proteins (HP). In this study, we considered 32 C. pseudotuberculosis biovar ovis genomes for the pan-genomic analysis, where were identified 172 HP present in a core genome composed by 1255 genes. We are able to functionally annotate 80 sequences previously characterized as HP through the identification of structural features as conserved domains and families. Furthermore, we analyzed the physicochemical properties, subcellular localization and molecular function. Additionally, through RNA-seq data, we investigated the differential gene expression of the annotated HP. Genes inserted in pathogenicity islands had their virulence potential evaluated. Also, we have analyzed the existence of functional associations for their products based on protein–protein interaction networks, and perform the structural prediction of three targets. Due to the integration of different strategies, this study can underlie deeper in vitro researches in the characterization of these HP and the search for new solutions for combat this pathogen.

Caracterização do perfil fitoquímico das flores de Turnera ulmifolia L. (Chanana)

A chanana (Turnera ulmifolia L.) é uma planta herbácea, nativa da América tropical, África, Índia e Sudeste da Ásia, com ampla distribuição geográfica nas regiões do nordeste do Brasil. A planta é bastante utilizada pela medicina popular, sendo suas flores usadas para o tratamento de lesões da pele e processos inflamatórios. Em vista da escassez de estudos relacionados à composição fitoquímica de suas flores, este estudo experimental teve como objetivo analisar o perfil fitoquímico das flores de T. ulmifolia, através de métodos qualitativos de detecção fitoquímica. O estudo foi desenvolvido por meio da análise de dois extratos, um aquoso (EAFC) e outro hexânico (EHFC), aplicando-se a maceração como método de extração. Os resultados demonstraram que as flores da chanana possuem uma variedade de metabólitos secundários, como alcalóides, esteróides, triterpenóides, antocianidinas, chalconas, cumarinas, flavonóides e taninos. Entre os extratos analisados, o EAFC mostrou ser mais rico em compostos fitoquímicos em comparação ao EHFC. O estudo demostrou que as flores são ricas em metabolitos secundários relevantes, os quais podem estar diretamente relacionados às suas propriedades medicinais descritas pelo uso popular. Além disso, esta pesquisa evidenciou a presença de compostos ainda não detectados em estudos relacionados à composição química da espécie, como triterpenos, antocianidinas e chalconas.

Veredas da Chapada do Araripe: subespaços de exceção no semiárido do estado do Ceará, Brasil

Na região do Cariri cearense, as singularidades naturais, sobretudo nas áreas de influência direta da Chapada do Araripe, reafirmam seu caráter de exceção dentro do semiárido do Nordeste brasileiro e definem as Veredas como subespaços de exceção. Neste artigo, busca-se apresentar as particularidades naturais das Veredas da Chapada do Araripe, que são possuidoras de Gleissolos Melânicos Tb distróficos, ácidos, muito intemperizados, com predomínio de cargas negativas. Esses solos sustentam renques de buritis, entre outras freatófitas, que são heranças de uma complexa evolução paleoclimática e paleoecológica, mantidos atualmente pelas influências das zonas de exsudação. As Veredas da Chapada do Araripe são classificadas do ponto de vista geomorfológico, pertencentes a 4 (quatro) tipos específicos: de Patamar, de Depressão em Chapadão de Sopé e de Encosta, formam-se nessas posições topográficas em função da profundidade do lençol freático, tendo seu processo evolutivo relacionado com o sistema de erosão e recuo de escarpa. As Veredas da Chapada do Araripe, encontram-se atualmente refugiadas e tensionadas pelo clima semiárido.&#x0D; Palavras-chave: Chapada do Araripe; Espaço de exceção; Veredas; Cariri cearense.

El perro no es el villano: ¿hablamos de leishmaniasis?

Nowadays, pets are considered members of the family, living with them provides numerous benefits to humans, however if dog and cat tutors do not have adequate information about responsible tutoring, these animals may be susceptible to abuse, abandonment and zoonoses. Canine visceral leishmaniasis (CVL) in Brazil is a zoonosis commonly caused by the protozoan Leishmania infantum and transmitted through the blood meal of female sandflies of the genus Lutzomia spp. This disease has a high mortality in humans and dogs, being considered a pathology of great importance for public health. In regions of North-eastern Brazil, a large number of non-domiciled animals are observed, in addition, visceral leishmaniasis is endemic in dogs and humans in this region, so the actions developed in this work aimed to raise awareness of dog tutors from the Northeast region, specifically from the high sergipano hinterland, about visceral leishmaniasis, demonstrating the etiology, measures of control and prevention of the disease. For this, activities were carried out at important events in the municipality, actions at the Federal University of Sergipe and visits to schools in the region. An average of 200 adults and 600 children were informed about ways to control and prevent the disease, in addition, these actions also aimed to educate that the disease is not transmitted through direct contact with the dog. This work contributed to the process of transforming the attitudes of the local population towards zoonosis, visceral leishmaniasis and responsibility towards animals, because these themes are essential for improving animal welfare and public health.

Particularidades do Português Tocantinense: resultados do Atlas Linguístico Topodinâmico e Topoestático do Estado do Tocantins (ALiTTETO)

O atual Tocantins, desmembrado do espaço goiano em 1988, apresenta características migratórias intensas, sobretudo de populações procedentes das regiões Norte e Nordeste, o que se traduz em ações centrípetas e centrífugas relacionadas às formas dialetais de informantes locais e migrantes. Em razão desse movimento de falantes plurivarietais, realizamos o “Atlas Linguístico Topodinâmico e Topoestático do Estado do Tocantins” – ALiTTETO (2018), defendido como tese de doutorado na Universidade Estadual de Londrina. O trabalho, lato sensu, foi composto por inquéritos realizados em 12 localidades, junto a 96 informantes estratificados por idade, sexo e mobilidade (migrante e não migrante). Neste recorte, fornecemos resultados nos níveis fonético-fonológico, mais precisamente na variação do rótico em coda medial, que atrela o Tocantins a uma norma fonética presente nas regiões Norte e Nordeste brasileira; e no viés lexical, com a apresentação das variantes para libélula/cambito/cavalo/cavalinho (de/do capeta, cão, judeu), que demonstra a formação de área dialetal nas proximidades com o espaço intitulado como Falar Baiano.

Ecossistema de Inovação em Bionegócio na Região Nordeste do Brasil

A interação entre bionegócios promove evolução do ecossistema de inovação. Analisar como estes negócios se relacionam possibilita entender o que favorece o surgimento de novos negócios e os casos de sucesso. O presente estudo analisou o ecossistema de inovação existente na região nordeste do Brasil, buscando caracterizar o ambiente de inovação. Os dados foram buscados em fontes de informações primárias e secundárias. Na região nordeste a legislação estabelece um ambiente de incentivo ao surgimento de novos negócios; as instituições de fomento favorecem o desenvolvimento de pesquisas e desenvolvimento de novos negócios. As Universidades, Parques Tecnológicos e Institutos de pesquisa, em parceria com empresa privadas, fazem com que os bionegócios sejam impulsionados. Há dificuldade no acesso aos dados produzidos pelas entidades supracitadas e ausência de interação entres todos os componentes do ecossistema de inovação. Assim, o gargalo encontrado foi a deficiência na gestão da inovação.

Recurrence-free survival and prognostic factors of odontogenic keratocyst: a single-center retrospective cohort.

The aim of the present study was to evaluate the 5-year recurrence-free survival and prognostic factors of odontogenic keratocyst (OKC) from a single-center retrospective cohort in the northeastern region of Brazil. Forty cases of OKC comprised the study population. In the cohort analyzed, 18 (45%) cases were recurrent OKCs and 22 (55%) were non-recurrent OKCs. Recurrence-free survival was defined as the period from the release of the histopathological report to the occurrence of relapse or last visit to the service. Comparison of the clinicopathological variables between primary and recurrent OKC lesions revealed no differences in the frequency of epithelial thickness, presence of satellite cysts and cystic spaces, presence of an inflammatory infiltrate, locularity, and lesion borders. The frequency of symptoms was practically the same even after recurrence. Satellite cysts were more frequent in the group of recurrent lesions (n = 9, p = 0.002) and the presence of an inflammatory infiltrate was also significantly associated with recurrent lesions (n = 15, p = 0.006). Previous decompression or marsupialization was associated with recurrence of the lesion (p = 0.010). In conclusion, the most significant prognostic factors were previous decompression or marsupialization, as well as, morphological parameters associated with the recurrence cases were the presence of an inflammatory infiltrate and satellites cysts. The risk of recurrence is low but continues due to the particularities of epithelial proliferation in OKC.

Helicobacter Pylori cagA+ Genotype is Associated With Consumption of Untreated Drinking Water in North-Eastern Brazil.

This study aimed to identify the Helicobacter pylori cagA+ genotype prevalent in a region of north-eastern Brazil and find possible associations between this genotype and socioeconomic variables. This cross-sectional study included 751 patients with dyspepsia from a public endoscopy clinic. Genotyping was carried out on 98 samples from gastric tissue with positive urease test for H. pylori using polymerase chain reaction (PCR). Socioeconomic variables were collected via forms. Pearson's χ2 test was used to analyze associations between variables and odds ratios were obtained to compare effects. Statistical significance was defined as p < 0.05 for univariate and multivariate analyses. H. pylori infection was present in 52.7% of the patients and associated with low income and consumption of untreated drinking water. The prevalence of the cagA+ genotype was 25.5%. Low income was inversely related to the presence of cagA+ genotype, even after adjustment. Untreated drinking water consumption was associated with the presence of the cagA+ genotype in both the univariate (p = 0.03; OR = 2.55; 95% CI: 1.008-6.48) and multivariate (p = 0.03; OR = 2.89; 95% CI: 1.08-7.67) analyses. The findings of this study suggest that water can be an important vehicle for the transmission of pathogenic H. pylori strains and may be a public health challenge, especially in less developed regions with precarious water and sanitary conditions.

PHYSICAL ACTIVITY LEVEL, FUNCTIONAL MOBILITY AND FALL RISK IN THE ELDERLY

Introduction: Low levels of physical activity and functional mobility lead to greater difficulty in performing activities of daily living and are directly proportional to mortality in the elderly. Thus, there are the need to create mechanisms linked to the maintenance of the functional capacity, which assure the elderly autonomy and self-confidence. Objective: To verify the level of physical activity and functional mobility in the elderly and if this functional mobility suffers interference of the age group and physical activity. Methods: The study involved the elderly aged 60 and over, living in Senhor do Bonfim (BA), in the northeastern region of Brazil, from February to July 2015. The evaluation of the subjects occurred in a single session, with physical and general clinical evaluation, as well as the collection of sociodemographic, anthropometric and self-reported morbidities through the application of questionnaires. It was also carried out the Timed Up and Go test (TUG) to verify the levels of functional mobility and level of physical activity with application of the International Questionnaire of Physical Activity (IPAQ) adapted for the elderly. Results: In this study, 127 patients were studied, predominantly female (87%) and mean age of 68 ± 7 years, and the majority of the elderly corresponded to the age group of 60 to 69 years. The elderly belonging to the group considered inactive (IPAQ up to 150 min/weekly) presented the execution time of TUG higher than the elderly in the group considered active (IPAQ &gt; 150 min/weekly), with averaging time for carrying out the test of 10.5±2 minutes and 8.9±2 minutes respectively, with a statistically significant difference of p&lt;0.01. And the execution time of TUG increased proportionally to the increase of the age group. Conclusion: Elderly with lower level of physical activity and belonging to the higher age groups present a higher risk of falls. Strategies should be developed to stimulate increased physical activity level and functional mobility of this population, especially among the older ones, reducing the incidence of falls and providing greater autonomy.

Comprehension and use of psychoactive substances by nursing undergraduates

Objective: The study’s main purpose has been to assess the comprehension and use of psychoactive substances by nursing undergraduates from a public university. Methods: It is a descriptive and cross-sectional study with a quantitative approach, which was performed with students of the Nursing Graduation Course from a federal public university located in the Northeastern region of Brazil. The data collected from a printed form were evaluated and classified using the Statistical Package for the Social Science (SPSS) version 23.0. Results: Substance use by students was led by alcohol (80%), followed by hypnotic-sedatives (12%), marijuana (11%) and tobacco (10%). There was a significant alcohol consumption in the month prior to the interview (29%). Concerning the theoretical knowledge, the majority of interviewees were aged between 17 and 25 years old (34.5%) and reported reading more than three texts on the topic. Conclusion: The problem of substance use is a topic of interest among nursing undergraduates despite the reported consumption pattern regarding both alcohol and tobacco in the same population.

Detection of Toxoplasma gondii DNA in heart tissue from common marmoset (Callithrix jacchus) monitored for yellow fever and rabies in Pernambuco state, Northeastern of Brazil.

There is limited available information concerning the prevalence of Toxoplasma gondii in noncaptive monkeys. Also, New World monkeys (NWM) are highly susceptible to toxoplasmosis, which is a conservation concern. This study aimed to investigate apicomplexan parasites in common marmosets (Callithrix jacchus) collected for yellow fever and rabies surveillance program in Northeastern region of Brazil. Heart fragments of 39 free-ranging common marmosets were analyzed for the presence of the 18S rDNA gene of apicomplexan parasites by nested PCR. Positive samples were sequenced. T. gondii DNA was detected in 17.9% (7/39) of the analyzed animals. This study is the first report on T. gondii in Callithrix jacchus in Brazil. These findings should be an alert for wildlife conservation institutions, as high susceptibility and mortality were reported for captive NWM.

New species of Augochlora (Oxystoglossella) Eickwort (Hymenoptera; Apoidea) from Northeastern Brazil with an identification key for the region.

Within Augochlorini, Augochlora Smith is one of the most speciose genera, with 118 species, and widely distributed groups, occurring from Argentina to Canada. The genus has a remarkable range of social behaviors and nesting substrate preferences. There are two recognized extant subgenera: Augochlora s.s., whose species nest in decaying wood cavities and Oxystoglossella, whose species nest in soil. To date, a single species revision is available for Central Argentina and Uruguay. In the present study we provide a revision of Oxystoglossella species occurring in Northeastern Brazil including the description of three new species: Augochlora bipunctata sp. nov., Augochlora modica sp. nov. and Augochlora tenax sp. nov. Herein Halictus eucnemis Vachal is resurrected from synonymy with Augochlora thalia Smith, and the lectotype of Halictus hemitomes Vachal is presently designated. Augochlora aurinasis is cited for Brazil for the first time. A key to the six species of Oxystoglossella occurring at Northeastern region in Brazil is provided. The three new species are apparently restricted to this region, being one of them probably linked to the Caatinga biome.

Quality and management status of the drinking water supplies in a semiarid region of Northeastern Brazil

Surface and groundwater resources in the Seridó Region (Brazilian semiarid) were investigated to evaluate their current quality conditions and suitability for domestic use. The water was characterized in terms of physical, chemical, and radiological parameters; including those required by the Brazilian Drinking Water Quality Standard (DWQS). Information about major and trace elements and radiological aspects of the water are reported for the first time. Salinization was confirmed as a key problem in the region, driven natural and anthropogenic. Overall, water has poor organoleptic characteristics. The concentration of most trace elements was below the recommended level, except for uranium and selenium in groundwater. Gross alpha and beta activities higher than the recommended levels were also recorded in several water samples, mostly from the investigated aquifers. In these samples, a detailed radionuclide analysis is required to estimate the effective dose received by the local population. Overall, the results show that water from the investigated region is not suitable for human consumption unless proper treatment is applied. Water requires proper treatment to decrease the content of dissolved salts, toxic elements, and radionuclides responsible for the high gross alpha and beta activities.

Probabilistic long-term reservoir operation employing copulas and implicit stochastic optimization

This paper explores and combines implicit stochastic optimization (ISO) with copula functions to simulate long-term operating policies for a hydropower reservoir located in the Northeastern region of Brazil. Overall, ISO is considered as one of the most reliable techniques to derive long-term reservoir operating rules for reservoirs. This method employs a deterministic optimization model to estimate the optimal reservoir allocations under different inflow scenarios and later constructs operating rules for each month by relating the ensemble of the optimal releases, the initial storage volume and future inflow values. Those rules are generally established by fitting approaches including linear regression or nonlinear methods. This work illustrates the applicability to combine copulas with ISO to define reservoir operation policies based on a probabilistic procedure. Firstly, synthetic streamflow scenarios are simulated using a periodic vine copula model. Afterward, optimal release data are estimated by ISO for a set of inflow scenarios. Joint probability distribution functions based on copulas are constructed in order to forecast the expected release, conditioned to the initial reservoir volume and future inflows data. Results indicate that the proposed model represents a flexible approach to construct operating rules and derive long-term reservoir operating policies with low variability, allowing to reproduce different dependence structures of simulated data.