1000 resultados para CNPQ::CIENCIAS BIOLOGICAS::ZOOLOGIA::COMPORTAMENTO ANIMAL
Resumo:
A degradação dos recursos naturais é talvez o principal problema da região do semiárido brasileiro, e essa degradação é principalmente resultante das perdas de solo, decorrente do processo erosivo. Na busca de melhor conhecer esta problemática vem sendo empregado o processo de modelagem ambiental, cujo objetivo é identificar e propor soluções para a degradação dos solos. Nesse sentido, o trabalho aplica o modelo da Equação Universal de Perda de Solos (EUPS), desenvolvido nos Estados Unidos ao longo da década de 1950, agregado as ferramentas de geoprocessamento, informações de sensoriamento remoto e Sistemas de Informações Geográficas (SIGs). A área de estudo é a Microbacia Riacho Passagem localizada na região oeste do Estado do Rio Grande do Norte, a microbacia tem uma área de 221,7Km² e esta inserida no semiárido, região Nordeste do Brasil. A metodologia utilizada consiste: em agrupar as variáveis da EUPS no ambiente SIG utilizando imagens de satélite, levantamentos bibliográficos e trabalhos de campo. Para determinação das extensões das vertentes foi empregado o Modelo RAMPA, e para adequar a EUPS as condições da área de estudo, foram realizados ajuste através de modelos estatísticos, aperfeiçoando o trabalho e os resultados gerados pelo modelo. Ao fim do processo foi desenvolvida uma pseudo linguagem no aplicativo Linguagem Espacial para Geoprocessamento Algébrico (LEGAL) disponível no software SPRING versão 5.1.2 servindo de suporte para o processamento das informações contidas no banco de dados, base da EUPS. Os resultados demonstram que inicialmente é necessário delimitar com precisão o período seco e chuvoso, informação fundamental para a EUPS, uma vez que o trabalho busca identificar a perda de solo por erosão hídrica. O modelo RAMPA apresentou-se satisfatório e com elevado potencial de aplicação na determinação dos comprimentos de vertentes utilizando imagens de radar. Quanto ao comportamento das extensões de vertentes, na microbacia, o mesmo apresentou uma pequena variação na porção leste, maiores vertentes, área próxima a desembocadura. Após a aplicação do modelo o valor máximo de perda de solo foi 88 ton/ha.ano com núcleos localizados no NEOSSOLOS LITÓLICOS e o mínimo 0,01 ton/ha.ano localizado no domínio dos LATOSSOLOS e NEOSSOLOS FLÚVICOS. A erosão provoca diminuição do perfil de solo, principalmente nos NEOSSOLOS LITÓLICOS, resultando em alteração no balanço hídrico e conseqüentemente aumento da temperatura do solo, podendo desencadear a desertificação. Os resultados e a metodologia do presente trabalho poderão ser aplicados na busca pelo desenvolvimento sustentável, na região do semiárido brasileiro, auxiliando na compreensão do binômio uso do solo e capacidade de suporte do meio natural.
Resumo:
The research is developed in areas of horticulture in the city of Natal, in the neighborhoods of Lagoa Azul, Pajuçara and Redinha, along the Doce River, border area with Extremoz city, Rio Grande do Norte State. The region of the fluvial plain of Doce River is located in an Environmental Protection Zone (ZPA-9). This is one of the ZPA which is not under the regulatory marks and there are several environmental problems caused by use and land occupation, featuring an evident disregard of environmental laws and whose protection is hindered by the lack of specific legal mechanisms. This study aims to provide an overview of the use of pesticides in the lower course of the Doce River, in Natal, Rio Grande do Norte, and to assess environmental degradation in the area through chronic toxicity tests using the microcrustaceous Ceriodaphnia dubia Richard 1894 (Cladocera, Crustacea) as test organism. Visits were made to the area in 2009 and 2010. To obtain information a diagnosis of the local situation was accomplished based on personal observation and non-participatory photographic record, with the aim of assessing the environmental characteristics, population diversity and work processes of horticulturists. During the visits four different points of the Doce River were chosen to collect water for ecotoxicological tests and survey of physico-chemical parameters (dissolved oxygen, pH, chloride, turbidity, conductivity and temperature), which were measured in the field using Multiparameter Probe (TROLL 9500). The adverse effects of pesticide use in the lower course of the Doce River is a major problem for both the environmental and human health, since many of the substances and active principles that enter in the composition of the products are synthesized molecules whose effects can only be evaluated through different studies on their actions and behavior at short, medium or long term
Resumo:
The knowledge known as "winter experiences" has been developed for centuries among country people in the Brazilian Northeast hinterlands. It consists in the systematic observation of the nature to forecast and protect people against the effects of droughts. This knowledge is transmitted orally through generations. These experiences are guided by the observation of the behavior of fauna, flora, stars, the weather in the holy days and other very specific aspects of the lives of country people. Almost all country people living in the rural area know at least one experience, but the Prophets of Rain are known as the communicators of winter prophecies formulated from the observation of the experiences. The country person is identified as a Prophet of Rain because of his close relationship with nature and his ability to forecast. No matter if the prophecies are always right, he possesses a vital social role, as his practices contribute to prevent, ease and encourage other people. The main aim of this work is to analyze the role of the winter experiences for the country people in the Seridó Potiguar. In this sense, we sought to understand to what extent this knowledge still orients the productive practices of farmers living in this region and identify which factors instigate the observation of winter experiences nowadays. 241 questionnaires were applied to farmers in the rural cities of Acari, Caicó, Parelhas and Lagoa Nova and interviews were conducted with 15 Prophets in the Seridó. The methodological framework of this work is the analysis of content proposed by Bardin (2010). In this study area, the experiences exert influence and relevance to the country people in the Seridó, because they consider them as a way to ease their anguishes face the possible drought in the region. The major role of the Prophet is to feed the hope of country people for better days, rather than contribute for the organization of the productive activities. Among the interviewed people, the forecast from the observation of winter experiences have greater credibility than the meteorological and disseminated by media. The Prophets of Rain base their prophecies on the set of natural elements present in the environment. Many factors stimulate the winter experiences by the Prophets nowadays, as cultural transmission, age, relationship with nature, level of education, faith, among others, but specially the productive activities (agriculture and cattle raising) and the droughts. The winter means abundance and happiness in this region and the experience is one of the ways that people find to minimize the anxiety and, according to their possibilities, to prepare for a year of droughts or for winter
Resumo:
Intensive production of tilápias, in cages or net tanks, has been proposed as an alternative to increase fish production, that would generate income and offer animal protein in different tropical and subtropical countries. However, this system of production enriches the aquatic environment with nutrients, principally nitrogen and phosphor derived from the dejections of the metabolism of food and eventual food surpluses consumed by the fishes; the alimentation of the fishes in this production modality is dependent on fish food. The emission of these nutritions in levels above the limit that the system is capable metabolize can provoke a phenomenon called eutrofization, putting in risk the quality of water for public and for fish production activities. In this context the work had as a goal to evaluate the trófico state of the four reservoirs for intensive production of tilapias in net-tanks, in other words, he maximum fish production that the reservoirs are able to hold, keeping the desired quantity of nutrient concentrations in water for public use. The results of the four ecosystems in the Boqueirão de Parelhas reservoir showed that it s possible to have an intensive production of tilapias in net tanks, in this environment the annual average concentration of phosphor, was below the considered critical limits to deflagrate the process of eutrofization in semi-arid regions. The carrying capacity of the Boqueirão de Parelhas reservoir depends on the conversion of the feeding facts and phosphor content in the food but it should vary between 100 and 300 tons per year over a variation in the conversion feeding factor of 1,7 to 2,0:1 and a variation in the P in the food of 0,7 to 0,9%
Resumo:
Brazil has about 8,500 km of coastline and on this scale, fishing is a historically important source of animal protein for human consumption. The national fishing background shows a growth of marine fishery production until 1985 and within this period it was recorded a steady decline. From the year 2003 fishing statistics aim to some "recovery" of the total fisheries production, which probably is related to a change in industry practice. The target of commercial fishing became smaller species with low commercial value, but very abundants. The coney, Cephalopholis fulva (Serranidae), is one of these species that have been suffering a greater fishing pressure in recent years. In order to provide data about the current situation of the genetic diversity of these populations, several molecular markers have been being used for this purpose. The prior knowledge of genetic variability is crucial for management and biodiversity conservation. To this end, the control region sequences (dloop) of mtDNA from Cephalopholis fulva (Serranidae) from five geographical points of the coast of Brazil (Ceará, Rio Grande do Norte, Bahia and Espírito Santo) and the Archipelago of Fernando de Noronha (FN) were sequenced and their genetic diversity analyzed. The FST values were very low (0.0246 to 0.000), indicating high gene flow between the sampled spots. The indices h and indicate a secondary contact between previously allopatric lineages differentiated or large and stable populations with long evolutionary history. Tests of Tajima and Fu showed expansion for all populations. In contrast, the mismatch distribution and SSD indicated expansion just for coastal populations. Unlike other species of the Atlantic which have been deeply affected by events on later Pleistocene, the population-genetic patterns of C. fulva may be related to recent events occurred approximately 130,000 years ago. Moreover, the data presented by geographical samples of the specie C. fulva showed high genetic diversity, also indicating the absence of deleterious effects of over-exploitation on this specie, as well as evidence of complete panmixia between all sampled populations
Resumo:
Decapod crustaceans are one of the most important portions of megafaunal of coastal waters, playing a role as modifier of the environment and controlling populations of other organisms. Among the Decapoda, crab (brachyuran) constitutes the dominant macrofauna of mangroves. Among brachyuran is the mangrove crab (Ucides cordatus, Linnaeus, 1763), which represents the main component of the macrofauna of mangroves, particularly in Northern and Northeastern Brazil. In Brazil, its distribution is known from the state of Amapá to the north of Santa Catarina. This species is distinguished by its economic importance, being one of the main fishing resources in Brazil, generating a significant impact on their natural populations. This reduction would result in loss of value to the product, preventing its commercialization. Although it´s great ecological and economic importance, there are few articles about the biological aspects of U. cordatus, mainly in the state of Rio Grande do Norte. This work aimed to study the population dynamics of the mangrove crab, Ucides cordatus (Linnaeus, 1763), in Conchas estuary, Porto do Mangue, northern coast of Rio Grande do Norte. During the period November 2009 to October 2010 the crabs were collected monthly, obeying predetermined lunar periods (new moon or full moon) in a mangrove area in Porto do Mangue - RN. With the aid of a steel caliper (0.01 mm) and a precision balance (0.01 g) were measured biometric variables related to the animal's carapace, major propodus chela, width of abdomen (female), length of gonopodium ( males) and total weight. In addition, it was recorded, the gonads and molt stages, for males and females. In total, 476 crabs were collected, with 338 males and 138 females. Males were larger, heavier and in greater proportion than females. The reproductive period for the species in this location was limited during the months November to May, suggesting a change in current environmental legislation for the closure period. Synchrony was observed between the morphological and physiological maturity with females maturing earlier, possibly, a reproductive strategy adopted, compared to the low fishing pressure in the area. The molting period occurred in the dry season peaking in October. The analysis of growth, based on the parameters of von Bertalanffy was calculated using the nonlinear fit using modes (AJMOD). High growth rates for both males (L = 7.54 cm, k = 0.95, t0 =- 00:08; tmax = 4.84) and females (L = 6.50, k = 1 , 2, t0 =- 0008; tmax = 3.28) were found, contrasting with data from the literature, using other techniques. Males had higher asymptotic width size and longevity, but a lower growth constant when compared with females. The estimated age, for males and females, reaching the minimum capture size was 1.82 years and 1.63 years respectively. The size of physiological maturity, when individuals are able to reproduce, was estimated at 1.4 years and 1.05 years, for males and females, respectively. The recruitment period for this species is seasonal, with two peaks of occurrence, one in the rainy season and one in the dry season. This work represented the first effort on understanding the ecology of the mangrove crab, to the northern coast of Rio Grande do Norte. However, further studies on its biology should be undertaken, especially those related to growth, and recruitment, where observed that literature is more scarce
Resumo:
Coastal and marine protected areas are created to protect habitat, avoid biodiversity loss, and to help maintain viable fisheries. However, most of these areas in tropical countries occurs in impoverished regions and directly affect the livelihood and survival of coastal communities which directly depend on fisheries and shellfisheries. Therefore, socioeconomic and conservation goals overlap. In this context, fishers should have a central place in resource management. They are critical resource users and their behavior directly affects the system. Shellfish resources are important sources of food, employment and income to fishing communities in Latin America. But despite its widespread use for food and income, there is an urgent need of more research on shellfish management. This research discusses the artisanal fisheries of Venus clam (Anomalocardia brasiliana) (Gmelin, 1791) (Bivalvia: Veneridae) in Brazil, and points out strategies to improve the system. Venus clam is a small and commonly exploited species for food and income on the Brazilian coast. This research was carried out at Ponta do Tubarão Sustainable Development Reserve (Brazilian Northeast coast), where there was no information available about who harvest, where or how much Venus clam has been harvested, despite this resource being exploited for generations. Clam fishery follows the pattern of socio-economic invisibility that general clam exploitation has in Brazil. Methods used were interviews, participatory monitoring and focal follow observation from January 2010 to May 2011. Results include: (a) the identification of shell fishers, (b) how harvest and meat processing are performed (mollusk beds, time spent, gross and net production), (c) the analisis of shell fisher income and their economic sustentability, and (d) the involvement of shell fisher families in data gathering and analyses for the first time. Based on the acquired knowledge, we propose a new institutional arrangement for clam fishery including co-management, fisheries agreement, compensatory arrangements and improvements for the Venus clam value chain such as the establishment of a minimum price for clam meat. This research also includes two other results: a general description for Venus clam harvesting in the Brazilian Northeast coast and a specific discussion about co-management of Venus clam in Brazil. The first one was possible through the meeting of several shell fisherwomen from other states during activities promoted by People of the Tides (PoT) project. PoT was an international initiative aiming to develop coastal communities that depend on mollusk for their livelihood. The second one is a comparison between PoT and Venus clam management at Pirajubaé Marine Extractive Reserve (Santa Catarina). It evaluates the success and failures of these only two initiatives involving co-management of A. brasiliana in Brazil
Resumo:
The aim of this study was to know the behavior of Santa Inês ewes in different physiological stages during the pre-slaughter management, as well as their body weight loss, blood hematocrit values and meat quality. 21 discard ewes were used, arranged into the following treatments: T1 = ewes which remained in lactation for 60 days with their respective lambs and slaughtered one day after weaning; T2 = ewes which remained in lactation for 60 days with their respective lambs and one more period of approximately 30 days without the lambs and afterwards slaughtered; and T3 = ewes which remained in confinement for 60 days and did not give birth during the year. The weight of ewes after transportation was lower for T1 in comparison with T2. Blood hematocrit values of ewes before and after transportation and after fast in the waiting pen were not different among the treatments, with mean value of 58.50%. We concluded that the quality of meat of discard ewes in different physiological stages is not altered by pre-slaughter management, when correctly performed (avoiding animal stress), concerning meat pH.
Resumo:
Discutimos as implicações da noção de adaptação que é uma noção chave para a teoria da evolução clássica. Em lugar de obstinar-se em considerar os organismos como coleção de traços adaptados, propomos buscar estudar a evolução por meio de um quadro teórico onde prevalece uma outra ontologia que destaca o fato de que os organismos e as circunstâncias são totalmente integrados. A etapa preliminar necessária para esta reconsideração consiste em passar de uma lógica prescritiva para uma lógica proscritiva. Isto é, da idéia de que tudo que não é permitido, é proibido; à idéia que o que não é proibido, é permitido. Propomos que a idéia de que os sistemas vivos especificam o mundo no qual eles vivem pode modificar nossa maneira de encarar os processos adaptativos.
Resumo:
Los trabajos de campo son experiencias que docentes y alumnos pueden utilizar como estrategia didáctica para desarrollar destrezas y aumentar la motivación al abordar el tema ciencias. En el presente trabajo se describe una metodología puesta en práctica con alumnos del Profesorado en Ciencias Biológicas, que se propone a los docentes para planificar sus salidas de campo. A partir del trabajo de campo desarrollado se pudo evidenciar la importancia de éste tipo de actividades didácticas extra-áulicas para el desarrollo de actitudes y destrezas, tales como la organización de tareas, colaboración entre pares, redacción de informes científicos, además, sobre la base de hipótesis y objetivos previos, el abordaje interdisciplinario para la observación y análisis del ambiente en estudio.
Resumo:
Los trabajos de campo son experiencias que docentes y alumnos pueden utilizar como estrategia didáctica para desarrollar destrezas y aumentar la motivación al abordar el tema ciencias. En el presente trabajo se describe una metodología puesta en práctica con alumnos del Profesorado en Ciencias Biológicas, que se propone a los docentes para planificar sus salidas de campo. A partir del trabajo de campo desarrollado se pudo evidenciar la importancia de éste tipo de actividades didácticas extra-áulicas para el desarrollo de actitudes y destrezas, tales como la organización de tareas, colaboración entre pares, redacción de informes científicos, además, sobre la base de hipótesis y objetivos previos, el abordaje interdisciplinario para la observación y análisis del ambiente en estudio.
Resumo:
The use of fossil fuels has been considered one of reason for the increase of pollution in the atmosphere and it may be related to the climate changes. Then, the research of the new sources of fuels will be important. Considering this, the use of biodiesel has been considered not as bad as petrol. The castor bean (Ricinus communis L.) is an important oilseed, which belongs to Euphorbiaceae family, and the oil found in the seed has important characteristics for biodiesel. This plant is considered as “rustic” as it does not need so much water for its development and oil production. Due to this, this plant has been considered to be ideal in semi-arid regions, such as the Northeast of Brazil. The aim of his study is to better understand the responses to abiotic stresses (drought and salinity) from castor bean plants using morphological, physiological and molecular tools. In order to do this, the castor bean plants were subjected to salt stress (50, 100, 150 and 200 mM NaCl) in a controlled environment and drought stress (5, 10, 15 days and 10 days cyclic). After these treatments, these plants were subjected to different analyzes: a) the expansion and retention of water from leaves; b) anatomy using leaves and roots. Based on these results, we found that castor suffered decrease in leaf area with increase drought stress, however restricted water loss, probably by accumulation of compatible solutes in the leaves. The anatomy data showed modifications in the vascular system. These modifications observed suggested that castor bean plant may be resistant to stress as it was verified in 5 days of drought as well as in 100 mM NaCl. In both conditions, these plants were fine. Probably these plants keep some solutes in the cell and then maintain the cell tugor. The data obtained in this study gave a better idea how castor bean plant responds to abiotic stress conditions - drought and salt stress
Resumo:
The environmental characteristics can modify the acoustics of a species due to habitat, time of day and year. Therefore, this study investigated the relationships between seasons, tide, daily cycle of tides, times of day and different habitat and noise emission of S. guianensis. Sound recordings occurred in the Curral’s Cove and Lagoon Complex of Guaraíras (CLG) in the municipality of Tibau do Sul/RN. Whistles are emitted with lower frequency during rainy season and spring tide while clicks are higher; whistles, clicks and calls have higher frequency during ebb tide. These modifications can be related with turbidity and prey availability. The whistles and clicks occurrence are higher at night probably because luminosity is lower. Furthermore, the whistles and clicks frequency reduction overnight allows the sound to travel longer distance and helps the view which is limited; but the minimum frequency increase was needed to catch the prey. The low occurrence of calls could be related to the small group size. The acoustic changes at night may be partly influenced by light levels as prey availability that is larger in this period. Whistle frequencies and click initial frequency are higher in CLG than Curral’s cove that permitted good precision. However, click central frequency is lower and may be connected to tracking the area. Several factors may be associated with such modifications as background noise, bottom and others. This study supports the hypothesis that S. guianensis presents an acoustic plasticity according to the local conditions where the species is embedded and adapts to the environmental changes.
Resumo:
The behavioral decisions of animals do not occur randomly, because behaviors are adjusted to ensure the survival and reproduction of the animal. In this research, I examined behavioral decisions in the foraging context of the ant Dinoponera quadriceps with regard to orientation, food avaliation and foraging dynamic to individual level. The study was conducted at the Laboratory of Behavioral Biology at UFRN and in an area of secondary Atlantic Forest in FLONA-ICMBio Nísia Floresta/RN. In all observations and experiments, ants were marked individually with an alphanumeric code label fixed on the thorax. In the first part of the study, I analyzed the orientation cues used by D. quadriceps. The tests were performed in a maze of 17 compartments. Each forager was tested for 10 min in three sessions for six different treatments. The treatments consisted of the presence or absence of odor and superior or frontal visual cues. The workers demonstrated that the presence of odor is indispensable and front visual cues are more effective than superior visual cues. In the second part, I investigated the discrimination of food, considering the parameters, size, weight and volume. In a 'cafeteria' experiment, I offered cylindrical pieces of food (mortadella) in a Petri dish, within an experimental arena 1m². Initially, the pieces were of four different sizes; in a second step, the pieces were of the same size but with different weight; in the last step, the pieces had the same weight but different volumes. The results showed the effect of the size and weight parameters for food choice. In the third part of the study, I evaluated the influence of the activity of active foragers on inactive ones. In this part, the colonies were observed in a natural environment. The observations took place on three consecutive days in 10 episodes, total of 30 days for each colony, 12 hours/day. On the first day, I registered the output and input of workers; on the second day, the most active ants on the first day were taken and given back at the end of the observations; on the third day, the observations were similar to the first day. As a result, the workers of D. quadriceps show autostimulation and they do not show social facilitation and the colony compensates the absence of the most active workers. Based on the stated, I conclude that workers of D. quadriceps use chemical, frontal and superior visual orientation cues during their displacements. They discriminate the chosen food by size and weight. The regulation of activity dynamics of foragers is by autostimulation, an active worker does not influence the activity of an inactive worker, the successful search previous is the stimulus to the successful worker itself to continue foraging activity.
Resumo:
Chondroitin sulfate (CS) is a naturally glycosaminoglycan found in the extracellular matrix of connective tissues and it may be extracted and purified those tissues. CS is involved in various biological functions, which may be related to the having structural variability, despite the simplicity of the linear chain structure from this molecule. Researches in biotechnology and pharmaceutical field with wastes from aquaculture has been developed in Brazil. In recent decades, tilapia (Oreochromis niloticus), native fish from Africa, has been one of the most cultivated species in various regions of the world, including Brazil. The tilapia farming is a cost-effective activity, however, it generates large amount of wastes that are discarded by producers. It is understood that waste from tilapia can be used in research as a source of molecules with important biotechnological applications, which also helps in reducing environmental impacts and promote the development of an ecofriendly activity. Thus, nile tilapia viscera were subjected to proteolysis, then the glycosaminoglycans were complexed with ion exchange resin (Lewatit), it was fractionated with increasing volumes of acetone and purified by ion exchange chromatography DEAE-Sephacel. Further, the fraction was analyzed by agarose gel electrophoresis and nuclear magnetic resonance (NMR). The electrophoretic profile of the compound together the analysis of 1H NMR spectra and the HSQC correlation allow to affirm that the compound corresponds to a molecule like chondroitin sulfate. MTT assay was used to assess cell viability in the presence of CS tilapia isolated and showed that the compound is not cytotoxic to normal cells such as cells from the mouse embryo fibroblast (3T3). Then, this compound was tested for the ability to reduce the influx of leukocytes in model of acute peritonitis (in vivo) induced by sodium thioglycolate. In this context, it was done total and differential leukocytes counting in the blood and peritoneal fluid collected respectively from vena cava and the peritoneal cavity of the animals subjected to the experiment. The chondroitin sulfate for the first time isolated from tilapia (CST ) was able to reduce the migration of leukocytes to the peritoneal cavity of inflamed mice until 80.4 per cent at a dose 10µg/kg. The results also show that there was a significant reduction (p<0.001) of the population of polymorphonuclear leukocytes from peritoneal cavity in the three tested doses (0.1µg/kg; 1µg/kg and 10µg/kg) when it was compared to the positive control (just thioglycolate). Therefore, since the CST structure and mechanism of action has been completely elucidated, this compound may have potential for therapeutic use in inflammatory diseases