Investment recovery period in electric motor of higher efficiency in pumping for irrigation

Neste trabalho, ajustou-se um modelo matemático para quantificar o efeito do rendimento do motor elétrico sobre os custos de um sistema de bombeamento para irrigação na estrutura tarifária de energia elétrica convencional e horo-sazonal verde, bem como calcular o tempo de recuperação do capital investido no equipamento de maior rendimento. em seguida, o mesmo foi aplicado a um sistema de irrigação tipo pivô central em duas opções de rendimento do motor elétrico: 92,6% (linha padrão) e 94,3% (linha alto rendimento), sendo que o custo de aquisição do primeiro correspondeu a 70% do segundo. A potência do motor elétrico era de 100 cv. Os resultados mostraram que o modelo permitiu avaliar se um motor de alto rendimento era viável economicamente em relação ao motor-padrão em cada estrutura tarifária. Nas duas estruturas tarifárias, o motor de alto rendimento não foi viável. Na tarifa horo-sazonal verde, somente seria viável se seu rendimento fosse 4,46% superior ao do motor-padrão. Na tarifa convencional, somente seria viável se o ganho de rendimento superasse 2,71%.

Fatores ambientais na distribuição de populações de Brachiaria subquadripara presentes no Reservatório de Barra Bonita-SP

Este estudo teve como objetivos monitorar a distribuição de populações de Brachiaria subquadripara e caracterizar seu ambiente de ocorrência em duas épocas (seca e águas). As coletas foram realizadas em julho de 2004 e janeiro de 2005 em pontos previamente selecionados e georreferenciados, os quais se constituíram de 13 pontos no reservatório Barra Bonita (sete pontos no braço do rio Piracicaba e seis no braço do rio Tietê). Foram realizadas coletas de solo nas margens dos rios, sedimento, água e plantas. A distribuição em relação à área de infestação das populações de B. subquadripara observada na estação chuvosa foi influenciada pela variação sazonal, a qual ocorreu de forma heterogênea em relação à densidade populacional. O rio Tietê foi considerado um ambiente mais eutrófico do que o rio Piracicaba tanto em relação ao solo quanto em relação à coluna d'água. As amostras de água coletadas no rio Tietê apresentaram valores médios de pH na estação seca de 7,02 a 7,82, e na estação das águas registrou-se maior amplitude de variação (6,80 a 8,0). A maioria dos pontos amostrados apresentou altos teores de matéria orgânica no sedimento, sendo observados teores menores que 1,3% em dois pontos de coleta na época da seca e em cinco pontos na época das águas.

Longitudinal distribution and seasonality of macroalgae in a subtropical stream impacted by organic pollution

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Seasonality of macroalgal communities in a subtropical drainage basin in Paraná state, southern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ephemeroptera, Plecoptera and Trichoptera assemblages in two Atlantic Rainforest streams, Southeastern Brazil

Comunidades de Ephemeroptera, Plecoptera e Trichoptera (EPT) em substrato rochoso foram estudadas em dois riachos do Parque Estadual Intervales. Coletas com um amostrador de Surber (10 subamostras aleatórias, 1 m²) foram feitas mensalmente de setembro de 1999 a setembro de 2000 e trimestralmente de dezembro de 2000 a setembro de 2001 nos Ribeirões Bocaina e Água Comprida. A fauna de EPT do Ribeirão Bocaina foi mais diversificada e mais abundante do que a do Ribeirão Água Comprida. A fauna de EPT foi bastante diferente entre os dois riachos, tanto do ponto de vista da composição faunística quanto do ponto de vista funcional. Os resultados indicaram que não houve um padrão sazonal claro da variação temporal da densidade.

O efeito do regime hidrológico do semiárido na composição de espécies durante dominância de cianobactérias em um reservatório tropical

The potentially toxic cyanobacterial blooms in water bodies are spread across the globe, resulting in the loss of water quality and adverse effects on human health. In arid and semiarid regions, the hydrologic regime characterized by an annual cycle of drought and rain, change the volume and the retention time of the reservoir. Such changes affect the limnological characteristics and causing changes in composition and biomass community of cyanobacteria. The reservoir Cruzeta (Zmax = 8.7 m) is a eutrophic water supply source located in the semiarid tropical (Northeast Brazil). Raised the hypothesis that the hydrological regime of semi-arid tropical is a determining factor in the availability of resources in eutrophic water sources, which influences the composition of dominant species of cyanobacteria. The aim of this study was to analyze the changes in biomass and species composition of cyanobacteria for two annual hydrological cycles and evaluate factors drivers. The study was divided into five distinct periods (dry 2010, rain 2011, dry 2011, rain 2012, dry 2012). The dominant group found in all periods was Cyanobacteria (99% of total biomass), which contributed to the low diversity. The filamentous species Cylindrospermopsis raciborskii was present at both points in almost every study. The colonial species Microcystis panniformis and Sphaerocavum brasiliensis dominated only in periods with lower volumes of water. The diatoms contribute more to the biomass during the period of severe drought. The point near the dam (P1) had phytoplankton biomass larger than the point near the tributary (P2). The dominant species of colonial cyanobacteria lasted until the overflow in P1, and P2 this dominance was until the first rains. The redundancy analysis indicated that physical factors such as light availability and water level were the main factors driving the seasonal succession of phytoplankton. The composition of phytoplankton in spring was alternated by species of filamentous cyanobacteria in conditions of poor stability of the water column, such as Cylindrospermopsis raciborskii, and colonial species under conditions of high stability of the water column, such as Microcystis panniformis and Sphaerocavum brasiliensis. The extremes of torrential rains and severe droughts, governed by the hydrological regime of the semi-arid region led to the availability of resources in the watershed, directing the spatial and temporal dynamics of phytoplankton in the reservoir Cruzeta

Uso de ferramentas por macacos-prego em manguezais

The present study discusses the geographical distribution and the context on the occupation of mangrove swamp areas by capuchin monkeys. In addition, we assess how the dispersion to the mangrove allowed the exploration of different food items, permitting the development of predation by ambush and the use of cracking tools. From 2004 to 2008 we surveyed the main estuaries of Brazilian Amazon coast, from northeastern state of Pará to the eastern boundary of the state of Maranhão, and recorded the presence of two species of capuchin monkeys in the mangrove forest areas. Cebus apella has been widely distributed in the mangrove at the estuaries examined (excluding C. libidinosus areas). Its presence is often related to Amazon forest remnants in the neighbourhood of the mangrove swamps and thus it is possible that some groups live in both kinds of habitats. However, we recorded some populations restricted only to mangrove swamp surrounded by open areas. On the other hand, Cebus libidinosus had a distribution more restricted and isolated in mangroves. Its pattern of habitat use is consistent with geographic distribution in mangrove patches. It seems that the possible contact zone previously proposed in the literature for that two species has no evident barriers in the mangrove. Furthermore, we record cracking sites and systematic observations on the tool use, carnivory and predation by ambush in Cebus libidinosus from 2006 to 2008. Cebus libidinosus is the only Neotropical primate species in which the tool use has been systematically recorded in nature. However all previous studies had been obtained is open areas (Cerrado and Caatinga). Thus, the present study is first one to report that behaviour in forested habitats in which the tool use to cracking by capuchin monkeys is associated with the consumption of meat. In the Caatinga and Cerrado, food shortages and terrestriality has been proposed by different authors to explain the evolution of tool use in primates. Here, we analyzed the relative contribution of these two variables as selective pressures for the tool use by capuchin monkeys in the mangrove forests, an ecological scenario in which food resources is available around the year and terrestriality is limited by structural habitat features, as the presence of stilt roots and muddy soil

Composição ictiofaunística e estratégias reprodutivas de quatro espécies de peixes nativos da Bacia Hidrográfica Piranhas - Assu, Rio Grande do Norte

This study focuses on the fish fauna composition and reproductive strategies of four native fish species in relation to environmental variables of the Piranhas-Assu hydrographic basin of the Caatinga biome, Rio Grande do Norte, Brazil. Fish and environmental data were collected monthly during the period September 2008 to February 2010, in the Marechal Dutra reservoir and River Acauã a tributary of Piranhas- Assu. The fish were measured, weighed and dissected, and the gonads were removed, weighed and examined macroscopically for identification and determination of gonad maturation stages. The results of this work generated seven articles. The first article is about the fish fauna composition of the Piranhas-Assu hydrographic basin, Rio Grande do Norte. The 602 fish samples captured were distributed in four orders (Characiformes, Perciformes, Siluriformes and Synbranchiformes), 11 families and 22 species, of which 17 are endemic to the Caatinga ecoregion. The order Characiformes was more representative followed by Perciformes, Siluriformes and Synbranchiformes. The second article is about the length-weight relationship and growth of seven native fish species Crenicichla menezesi, Cichlasoma orientale, Triportheus angulatus, Psectrogaster rhomboides, Pimelodella gracilis, Prochilodus brevis and Leporinus piau from a semiarid Brazilian reservoir. The third article is about the reproductive aspects of Crenicichla menezesi. Males were larger, heavier and with a slight predominance as compared to females. Four stages of gonadal development were characterized, being immature, maturing, mature and spent. The females reached sexual maturity earlier than males, with an average fecundity of 398 oocytes per batch. The spawning was partial with a long reproductive period. The fourth article deals with the reproductive strategy of Leporinus piau a neotropical freshwater fish in semi-arid region of Brazil. The population of L. piau (n = 211) showed a slight predominance of males (55%), with larger and heavier females. The males matured earlier than the females. This species presented total spawning, with an average fecundity of 55,000 mature oocytes. Rainfall and concentration of dissolved oxygen acted as influential factors during the spawning season. L. piau shows a seasonal reproductive strategy. The fifth article is related to the morphometric-meristic characteristics and reproductive aspects of freshwater sardine, Triportheus angulatus from River Acauã of the Caatinga biome. There was a predominance of larger females, reaching first maturation before males. There was total spawning during the rainy period of the region. The sixth article reports on the reproductive strategy of Psectrogaster rhomboides. The sex ratio was 1M: 1F, with negative allometric growth. Males reached sexual maturity earlier than females Females and males showed four stages of gonadal development and spawned during the rainy season. The fecundity was low and this species presented total spawning. The seventh article reports on the dynamics of territorial behavior of Crenicichla menezesi. Ten agonistic behaviors displayed by the males were observed: frontal and lateral threat, chasing, circular chasing, perpendicular, lateral and mouth attacks, escape, parallel positioning and stationary. The formation of four social groups was observed among males: without interaction; interaction with submission and escape; with frontal and lateral agonistic interactions. In social interactions between males and females, it was observed that the larger males interacted more among themselves and with the larger females. The large male established its territory and the two small males along with the small female were excluded from the other groups. These studies clarified the fish fauna composition and reproductive strategies of four native species Crenicichla menezesi, Leporinus piau, Triportheus angulatus and Psectrogaster rhomboides of the Piranhas- Assu hydrographic basin of the Caatinga biome, Rio Grande do Norte, Brazil.

Estratégia reprodutiva do peixe-voador, Hirundichthys affinis e do peixe agulha preta, Hemiramphus brasiliensis no litoral de Caiçara do Norte, Rio Grande do Norte, Brasil

The flyingfish, Hirundichthys affinis (Günther, 1866) (Exocoetidae) and ballyhoo half beak, Hemiramphus brasiliensis (Linnaeus, 1758) (Hemiramphidae) are marine fish species of commercial value, which contribute to artisanal fishery production of Rio Grande do Norte, Brazil. Besides the economic importance, these fish are important from an ecological point of view, being components in pelagic food chain, where they are the preferred prey of larger predators of high commercial value. This study aimed to determine the reproductive strategies of H. affinis and H. brasiliensis and the fishery production of H. affinis in the northern coast of Rio Grande do Norte. The results are presented in the form of six cientific articles and a review paper. The first article presents the morphometric measurements and meristic counts which confirmed the taxonomic status, population structure in length-weight and the gonad development of H. affinis through macroscopic observations of the ovaries and testes. Females of this species were bigger and heavier than males. The second article describes the reproductive tactics, such as, sex ratio, length at first sexual maturity, histological aspects of gonads, fecundity and spawning season, that indicate the reproductive strategy of H. affinis. The third article shows annual changes in the fishery production of H. affinis in Caiçara do Norte, during the period of 1993 to 2010, emphasizing the relevance of this fish in total fishery production of Rio Grande do Norte, besides registering the fall in production in the years 2008 to 2010. The fourth article describes the population structure, with respect to the length and weight, the length-weight relationship, growth type and sex ratio of Hemiramphus brasiliensis. The fifth article describes the reproductive biology of H. brasiliensis, with details about sex ratio, length at first sexual maturity, fecundity, type of breeding and spawning season. The sixth article deals with the reproductive strategy of H. brasiliensis. The review paper presents the topic of age determination of tropical fish using analysis of otoliths. Both species use the coastal waters of Caiçara do Norte for reproductive purposes. The flying fish, H. affinis migrates from the oceanic waters to the coastal waters to reproduce, coinciding with the rainy season. H. affinis presents total spawning and a seasonal reproductive strategy. However, H. brasiliensis lives and reproduces in the coastal waters displaying partial spawning and an equilibrium reproductive strategy

Caracterização do ritmo de atividade motora durante a puberdade em sagüis (Callithrix jacchus) sob condições semi-naturais

Most of ontogenetic studies on circadian timing system have been developed on infants, adults and elderly. The puberty has not been a stage of life few studied, except for researches in human adolescents, that presents phase delay in sleep-wake cycle. However, few studies have focused on the basis of this circadian change due to methodological difficulties. Thus, an animal model to study the sleep-wake cycle at puberty is essential. In the common marmoset, a social primate, the circadian activity periodicity stabilizes around 4 months (juvenile stage) and the 8h period component has a seasonal variation. Puberty stage of this species begins near the 8th month of age in males and near the 7th month in females with 7 months of duration. With the aim to characterize the circadian motor activity rhythm during puberty in marmosets (Callithrix jacchus) the motor activity was continuous registered by actiwatches in 6 animals between 5-12 months. Since the social factor influence the behavior of this specie, behavioral observations were realized in 30 minutes windows twice/week to a general evaluation of the influence social interactions dynamic across experiment. Determination of puberty onset was done by fecal progesterone and estrogens in females, and androgens in males. From the analysis of the multiple regression test was selected a model that evaluate age and seasonal variables effect on the activity rhythm according to the higher explanation coefficient. The total activity was the only parameter influenced by age. Moreover, the activity onset was the parameter more explained by the model, and the sunrise was the factor that most influenced it. After the puberty onset, 2 dyads advanced the activity onset. The activity total decreased in 1 dyad and increased in 2 dyads. This increase may be related to the birth of infants in these families. The motor activity circadian component stabilized later in 1 dyad, coinciding with the puberty onset of these animals, while bimodality, caused by the 8 h component, was modulated by seasonality. The agonistic behavior was not evaluated due to reduced number of events. There were changes across ages in affiliative behavior of contact in 1 dyad, grooming done in 1 animal and grooming received in 2 animals. Although there is evidence of puberty effect on the activity motor rhythm, the photoperiodic fluctuations influenced the rhythm. Therefore is not possible to affirm if the puberty modulate the activity rhythm in marmosets

Ocorrência e Interações de Recém-nascidos e Filhotes de golfinho-rotador Stenella longirostris na Baía dos Golfinhos, Fernando de Noronha

Studies indicate that spinner dolphins use the Baía dos Golfinhos, in Fernando de Noronha Archipelago, for resting, reproduction, parental care and protection against shark attacks. The present study had the purpose of verifying the seasonality of spinner dolphin newborns and calves in relation to the months of the year and the pluviometric seasons (dry and rainy), as well as their interaction with the number and gender of accompanying adults and their positioning in relation to the adults (vertical, horizontal, and depth) in the above mentioned bay. The analysis were made out of photo records of dolphins collected between 2000 and 2006 (seasonality) and between 1995 and 2006 (interaction) both using ad libitum sampling method during free dives. To determine the age category, the reason between the smaller dolphin s total body length and the bigger dolphin s total body length was calculated. The dolphins were then divided into three age groups: adults, newborns and calves. Those with total body length ≥ 170cm were considered adults, newborns up to 105cm, and calves from 106cm to 128cm. In addition, the secondary characters described in literature were used to identify newborns and calves. The adults had dimensions of total lenght ≥170cm , the newborns until 105cm and calves between 106cm and 128cm. I addition, secondary characteristics described in the literature were used to indentify newborns and calves. The number of spinner dolphin newborns was greater in the month of April and higher during the rainy season. Throughout the months and pluviometric seasons (pluviometer/pluvial metric), the number of calves did not have a significant difference. Concerning to the presence of newborns and calves age groups at Baía dos Golfinhos, there was not a significant difference. It was possible to identify the gender of the escorting adults as (42), 95.24% being females and 4.76% males. Newborns were more frequently seen in the company of two adults, whereas calves were more often accompanied by more than two adults However, there was not a significant difference for the newborns, whereas for the calves there was a significant difference for those classified as loners and those accompanied by more than two adults. When in vertical positioning, the newborns and calves were more frequently observed in inferior position with some difference demonstrated between some of that. While in horizontal positioning both age groups were more often seen in posterior position, also with differences between them. In the depth perspective newborns and calves were positioned anterior, however with significant difference for the calves. The occurrence of a peak of newborns in the months of April may indicate the existence of a birth seasonality pattern for the beginning of the rainy season, with births scattered throughout the year. The results for the positions and escorting of newborns and calves are related to protection and suckling. These conditions reinforce the importance of the area when it comes to the care for offspring, which calls for the creation of conservation rules to the area, especially during those months with greater occurrence of newborns

Ritmo de atividade de forrageio de Dinoponera quadríceps em ambiente natural

In order to characterize the seasonal and daily rhythm of Dinoponera quadriceps foraging activity in natural environment, four colonies of D. quadriceps were observed in an area of secondary Atlantic forest in northeastern Brazil. Data collection was performed during 72 hours every three months during an annual cycle. Colonies of D. quadriceps exhibited seasonal variation in foraging activity, peaking in the early dry season, followed by a sudden decline at the end of this season and increasing again at the late rainy season. The seasonal rhythm of foraging was positively related to the duration of the daylight and luminosity, and negatively to the time of sunrise and rainfall. Regarding the daily rhythm, foraging activity was predominantly diurnal independent of season. At the early dry season, the colonies had two activity peaks, one in the morning and another in the afternoon, with a decrease in foraging at midday, while in the rest of the year foraging activity was distributed more evenly throughout the daylight. The daily rhythm of foraging activity had a stronger and positive relation with light intensity. The second most important factor determining the daily rhythm of foraging was temperature that was also positively related for most of the year. Relative humidity showed a weak and negative relation with the daily rhythm of foraging in just one month of observation

Ecologia alimentar e comportamento de forrageamento de Ameivula aff. ocellifera (Squamata: Teiidae) em área de caatinga do nordeste do Brasil

This study investigated the influence of intrinsic and extrinsic factors on the feeding ecology and foraging behavior of the whiptail lizard Ameivula aff. ocellifera, a new species widely distributed in the Brazilian Caatinga, and that is in process of description. In attendance to the objectives, the Dissertation was structured in two chapters, which correspond to scientific articles, one already published and the other to be submitted for publication. In Chapter 1 were analyzed the general diet composition, the relationship between lizard size and prey size, and the occurrence of sexual and ontogenetic differences in the diet. Chapter 2 contemplates a seasonal analysis of diet composition during two rainy seasons interspersed with a dry season, and the quantitative analysis of foraging behavior during two distinct periods. The diet composition was determined through stomach analysis of lizards (N = 111) collected monthly by active search, between September 2008 and August 2010, in the Estação Ecológica do Seridó (ESEC Seridó), state of Rio Grande do Norte. Foraging behavior was investigated during a rainy and a dry month of 2012 also in ESEC Seridó, by determining percent of time moving (PTM), number of movements per minute (MPM) and prey capture rate by the lizards (N = 28) during foraging. The main prey category in the diet of Ameivula aff. ocellifera was Insect larvae, followed by Orthoptera, Coleoptera and Araneae. Termites (Isoptera) were important only in numeric terms, having negligible volumetric contribution (<2%) and low frequency of occurrence, an uncommon feature among whiptail lizards. Males and females did not differ neither in diet composition nor in foraging behavior. Adults and juveniles ingested similar prey types, but differed in prey size. Maximum and minimum prey sizes were positively correlated with lizard body size, suggesting that in this population individuals experience an ontogenetic change in diet, eating larger prey items while growing, and at the same time excluding smaller ones. The diet showed significant seasonal differences; during the two rainy seasons (2009 and 2010), the predominant prey in diet were Insect larvae, Coleoptera and Orthoptera, while in the dry season the predominant prey were Insect larvae, Hemiptera, Araneae and Orthoptera. The degree of mobility of consumed prey during the rainy seasons was lower, mainly due to a greater consumption of larvae (highly sedentary prey) during these periods. Population niche breadth was higher in the dry season, confirming the theoretical prediction that when food is scarce, the diets tend to be more generalized. Considering the entire sample, Ameivula aff. ocellifera showed 61,0 ± 15,0% PTM, 2,03 ± 0,30 MPM, and captured 0,13 ± 0,14 per minute. Foraging mode was similar to that found for other whiptail lizards regarding PTM, but MPM was relatively superior. Seasonal differences were verified for PTM, which was significantly higher in the rainy season (66,4 ± 12,1) than in the dry season (51,5 ± 15,6). It is possible that this difference represents a behavioral adjustment in response to seasonal variation in the abundance and types of prey available in the environment in each season

Resíduos orgânicos como recondicionante de subsolo degradado e efeitos na atividade microbiana e fertilidade em cultivo de barbatimão

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Frequencia de enteroparasitoses em usuários do servico público de saúde na mesorregião do oeste potiguar

Em um mundo de grande pobreza, as enteroparasitoses podem exercer um papel importante no que se refere às desigualdades sociais, pois estas mazelas se apresentam, em sua grande maioria, na população mais carente. Estas mesmas doenças causam inúmeros casos de faltas ao trabalho e a escola, gerando preocupação dos profissionais de saúde, já que estes parasitas podem agravar ou desencadear quadros de anemia e desnutrição. O trabalho procurou pesquisar a prevalência de enteroparasitas na Mesorregião do Oeste Potiguar, em uma população que utiliza o sistema público de saúde, buscando associar as variáveis, como: sexo, faixa etária, período sazonal, renda familiar e número de parasitas. Foi utilizada a técnica de Hofmann (sedimentação espontânea) e o material fecal foi analisado pelos funcionários do Laboratório Central de Mossoró e Pau dos Ferros. Foi realizado no período de 02 de março de 2010 a 28 de março de 2011 o exame coprológico em 16.246 pessoas no laboratório Central de Mossoró (Lacen) e Pau dos Ferros, RN. A análise dos exames mostrou que 69,23% dos infectados eram mulheres e 33,07% eram homens. A maior prevalência ocorreu com Endolimax nana (41,61%), seguido de Entamoeba coli (18,46%) e Giardia lamblia (18,59%) em 3.407 parasitas encontrados. Dentre os exames realizados, o Endolimax nana foi o mais prevalente entre os organismos encontrados. A diferença nos resultados entre mulheres e homens pode determinar um foco domiciliar, pelo descaso do poder público com as políticas de saneamento básico e falta de higiene da população, e pela atividade das mesmas com trabalhos domésticos