71 resultados para Comunidade de peixes


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This thesis is defined as a reflection on the mechanisms of expression and insertion of the homo situs in the participatory governance in Mozambique. For a better understanding of this social fact, it was settled a periodization which covered the decline of colonialism at the time of the independence, which was proclaimed in June 1975, the civil war that lasted over 16 years and the period of the democratic State, further established. Therefore, we sought to understand the mechanisms and failures of the participation of the homo situs in local development projects that absorbed the needs and problems of these peasants, not mobilizing the skills and social competences of these communities. It would be essential for the homo situs a genuine democratic practice involving a political culture based on the social construction of the territories of the traditional man which was characterized by being procedural and historical, finding in participation its higher base. In this context, it would be desirable that the community development in Mozambique could contemplate and respect the choices of the homo situs. For this purpose, it would be fundamental the consistency between theory and practice, which builds and rebuilds, continually the competence of the peasants, facilitating the possibility of realization of their primordial aspirations. In the research, it became apparent that there is not a continuous process of participation of the rural communities, which appear as participants, only at the time of the implementation of the activities. Therefore, even having the participation of the communities expected by the law, with predictable moments of discussion and necessary conditions for that, the State failed to establish an ongoing process of democratic dialogue with traditional populations, as well as it failed to organize, properly, accurate informational bases to help solve the problems of rural areas. These facts have led to obstacles to the process of conquest of the human and civil rights of the traditional communities

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The food chain theory predict that presence of omnivory prevent the trophic cascade and could be a strong stabilizing factor over resource and consumer community dynamics, and that the nutrient enrichment destabilize populations dynamics. Most of the freshwater tropical reservoirs are eutrophic, and strategies that seek improve the water quality through the control of phytoplankton biomass and nutrient input, become essential for the improvement and preservation of water quality. The aim of this study was test the zooplanktivory (when larvae) and omnivory (when young and adult) effects of Nile Tilapia over the structure and dynamics of plankton communities, in addition or absence of nutrients enrichment. For this, one field experiment was performed with a factorial design 2x3 resulting in six treatments: control, without fish and nutrient (C); with omnivorous fish (O); with zooplanktivorous fish (Z); without fish and with enrichment of nutrients (NP); with omnivorous fish and nutrients (ONP); and, with zooplanktivorous fish and nutrients (ZNP). The two planktivory types reduced the zooplankton biomass and increased the phytoplankton biomass, but the omnivory of filter-feeding fish attenuated the trophic cascade magnitude. The fertilization by nutrients increases the nutrient concentrations in water and the phytoplankton biomass, but the effect on zooplankton is dependent of the trophic structure. In a general way, the effects of the fish and nutrient addition were addictive, but significant interactions among those factors were observed in the answer of some zooplankton groups. The effects of omnivorous fish over the temporal variability of phytoplankton and zooplankton biomass were very variable, the increase or reduce in variability of the plankton depending of the level of nutrients and of the analyzed variable. With base in this study, we conclude that the planktivory type exercised by the fish and the concentrations of nutrients in the water affects the force of pelagic trophic cascades and probably the success of biomanipulation programs for the handling of water quality in lakes and tropical reservoirs

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The omnivorous filter-feeding fish, Nile tilapia (Oreochromis niloticus), can have negative effects on water quality enhancing the eutrophication process. These effects depend on the nutrient enrichment level in the water. We carried out a mesocosm experiment for five weeks in a tropical man-made lake in Brazil to test ifthe effects of tilapias depend on of the level of nutrient enrichment. The experiment lasted for 5 weeks and a factorial 2x5 experimental design was used where the presence and absence of tilapias were manipulated in combination to 5 different levels of nutrient load in a total of 10 treatments. A two way repeated measure ANOVA was performed to evaluate the effects of time (t), tilapia (F), nutrients (NP) and the interactions among these factors on: chlorophyll a, water transparency, total phosphorous, total nitrogen, N:P ratio, zooplankton biomass and phytoplankton biovolume. The tilapia effect was evident, but nutrient enrichment didn t have any effect on the variables analyzed. Tilapia decreased the water transparency, total zooplankton biomass, calanoid copepod biomass, nauplii copepod biomass and cladocerans biomass. On the other hand, tilapia had no effect on phytoplankton biovolume. This lack of effect on phytoplankton is probably due to tilapia grazing that may counteract the positive effect of tilapia on phytoplankton via trophic cascades and nutrient recycling. Hence, a reduction in tilapia stock would not be an effective way to reduce phytoplankton biomass and improve water quality

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Nile tilapia, Oreochromis niloticus, is an important omnivorous fish in the reservoirs of the semi-arid region of Brazil. Throughout its growth tilapia s feeding behavior changes from a visual predator of zooplankton to a filter-feeder, collecting suspended particulate matter, including planktonic organisms, through pumping. This feature results in different impacts of tilapia on plankton community as the fish grows. Aiming to quantify the functional response of different sizes of Nile tilapia on zooplankton experiments in microcosms scale in the laboratory and in mesocosm scale in the field were carried out. The data were fitted to four different models of functional response. The best fits were obtained for nonlinear models in laboratory experiments. While the experiments in mesocosms were the best settings for responses of type I (juvenile and adult tilapia) and type III (fry). The Manly's alpha index was used to evaluate the feeding selectivity of tilapia on the three main groups of the zooplankton in the experiments in mesocosms. The results show that: (i) rotifers were the preferred prey of fingerlings,(ii) copepods were rejected by fry and juvenile tilapia and (iii) adult fish fed non-selectively on copepods, cladocerans and rotifers. The functional response models obtained in this research can be applied to population models and help in modeling the dynamics of interactions between Nile tilapia and the planktonic communities in the reservoirs of the semi-arid

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Cytogenetic studies in fish have been contributed significantly to a better understanding of the marine biodiversity, presenting information related to characterization, evolution and conservation of species e fisheries stocks. Among the marine species which cytogenetic data are less well known pelagic forms are detached, that despite the economic importance and conservation efforts have been suffering great pressure from the artisanal and industrial fisheries. The present work characterized cytogenetically six species of large pelagic fish in the Atlantic, belonging to the Order Perciformes, among them, four species of Scombridae, Thunnus albacares, T. obesus, Scomberomorus brasiliensis and Acanthocybium solandri and two Coryphaenidae, Coryphaena equiselis and C. hippurus using Classical cytogenetic methods as conventional staining, C-banding and Ag-NORs and molecular through staining fluorochromes AT and GC-specific and mapping of ribosomal multigene families, 18S and 5S. The identification of phylogenetic patterns and cytotaxonomic markers between the species and the presence of sex chromosomes in at least one species of Coryphaenidae, are particularly useful in the formulating of phylogenetic hypotheses, as well as comparisons between groups and populations

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Brazilian Northeast is the most vulnerable region to climatic variability risks. For the Brazilian semi-arid is expected a reduction in the overall rates of precipitation and an increase in the number of dry days. These changes predicted by the IPCC (2007) will intensify the rainfall and droughts period that could promote the dominance of cyanobacteria, thus affecting the water quality of reservoirs, that are most used for water supply, in the semi-arid. The aim of this study was to evaluate the effects of increasing temperature combined with nutrient enrichment on the functional structure of the phytoplankton community of a mesotrophic reservoir in the semi-arid, in the worst case scenario of climate change predicted by the IPCC (2007). Two experiments were performed, one in a rainy season and another in the dry season. In the water sampled, nutrients (nitrate and orthophosphate) were added in different concentrations. The microcosms were submitted to two different temperatures, five-year average of air temperature in the reservoir (control) and 4°C above the control temperature (warming). The results of this study showed that warming and nutrient enrichment benefited mainly the functional groups of cyanobacteria. During the rainy season it was verified the increasing biomass of small functional groups of unicellular and opportunists algae such as F (colonial green algae with mucilage) and X1 (nanoplanktonic algae of eutrophic lake systems). It was also observed an increasing in total biomass, in the richness and diversity of the community. In the dry season experiment there was a greater contribution in the relative biomass of filamentous algae, with a replacement of the group S1 (non-filamentous cyanobacteria with heterocytes) for H1 (filamentous cyanobacteria with heterocytes) in nutrient- enriched treatments. Moreover, there was also loss in total biomass, species richness and diversity of the community. The effects of temperature and nutrients manipulation on phytoplankton community of reservoir Ministro João Alves provoked changes in species richness, the diversity of the community and its functional composition, being the dry period which showed the highest susceptibility to the increase in the contribution of potentially toxic cyanobacteria with heterocytes

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The black communities, nowadays known as quilombolas, have long been segregated in social and cultural distances in relation to other groups in the country. Gradually, the establishment of public policy has enabled the inclusion of these social communities in new instances, favoring the improvement of standards of learning. In order to know the route of the school in relation to its surroundings, this paper presents a reflection on the educational history of the Municipal School Padre Armando de Paiva, inserted in the context of afrodescendência (African descendants), in the community called Sibaúma, municipality of Tibau do Sul - RN, characterized as the object of this study. Methodologically, this study is limited in a descriptive research of the historical reconstruction of the school, a case considered worthy of analysis. From a reflection on the presence of African descent in Brazil and in Rio Grande do Norte, the study also presents information on education in Brazil. Finally, it presents the trajectories directed to the analysis of physical conditions, the dynamics of registration, and avoidance of repetition of its students and the qualifications of its teaching staff. Survey selected for analysis five-year academic periods, a series which began in the year nineteen eighty and ends in the year two thousand and ten

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The research was carried out in the urban area in Codó-MA, a small city the east part of Maranhão, which has 4,228.000 km2 (IBGE, 2000) and population of 113,768 hab. (IBGE, 2008). The city is also inside Codó-MA micro-region. The city is located in one of the lacking area in Brazil, where the Human Development Index (IDH) is approximately 0,558. It does not present an adequate model of management when talking about solid residue collecting. All of the solid residue produced and collected in the city is stored in an open area that they call lixão , which is located in a residence area in the suburbs. Because of that, a problem that involves public health and environmental areas, we understand it is necessary to investigate the way the local government treats and manages the solid residue collecting, as well as, the social, economical and productive reality of those who are directly involved in the collecting itself, its productive chain of the material, including the handling, transportation and its final destiny. It means a social, productive, economical diagnosis, that in a such way,the local society and the organs of inspection can act in a better way to control the problems that include solid urban residue and come from a bad administration. That way, this work proposes to carry out a study that has as result a diagnosis with feasible alternatives on management, taking as basis, social and economical aspects that compound this productive chain. This work can bring great contributions to a better local reality through the introduction of an integrated and supported system of management of solid residue that includes a selective collecting and the creation of a sanitary area. Taking that into consideration, we can contribute to minimize the environmental impacts in Codó Novo, caused by the garbage

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Youngsters and teenagers are still a very vulnerable group of DST/AIDS. In order to combat this vulnerability the community intervention project being developed in Mãe Luiza neighborhood in the city of Natal-RN, entitled Strengthening Community Action Network for Prevention in HIV/AIDS: knowledge and Intervene emerged, popularly known as Project Viva Mãe Luiza. The project develops workshops of educomunication whose approach involves the DST/AIDS subject with the following media: video, photography, and theater playbook. This research integrates the activities of the project and has as main objective to investigate how strategies and practices of media communication developed in Project Viva Mãe Luiza through workshops of educomunication, assisted learning for the prevention of DST/AIDS and contributed to the reduction of vulnerability to DST/AIDS among adolescents and young participants of the project residents of Mãe Luiza community. The methodological basis was based on intervention research, with the technique of gathering daily field data, literature and documentary, in-depth interviews and ethnographic observation. The qualitative analysis was based on the monitoring of video workshops, photography, theater and primer, respectively, crossed by transverse to the prevention of DST/AIDS, conducted between June 2012 and December 2013 issues. Interviews with eight multipliers, aiming to understand their perceptions of vulnerability, prevention, multiplication and use of media that were part of the project were conducted. The analyzes show that learning workshops educomunication community health repercussions both in the development of individual skills in communication as changing perceptions about the vulnerabilities to which they are exposed, the awareness about prevention at the individual and differentiated actions multiplication in the community

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Human aging is physiological process causes alterations in several systems of the organism. In the musculoskeletal system, a main change is the decreased muscle strength, that in the lower extremity, compromises the ability to respond quickly with enough strength to prevent falls, causing alterations in postural balance. Currently, many researchers have study the human frailty, defined as a multifactorial syndrome, with excess of vulnerability to stressors, reducing ability in maintaining or regulating homeostasis. Its characteristics are directly related to physical function. Aim: To analyze muscle performance and postural balance in frail and pre-frail elderly women, and to compare them according with the frailty phenotypes criteria proposed by Fried 2001. Method: 39 frail elderly women living in the community, aged 65 years and older, were assessed muscle performance of lower extremity using isokinetic dynamometer and postural balance using Berg s balance scale and computerized baropodometry. Results: There was significant difference in plantar flexor, knee flexor and knee extensor strength, in anteroposterior (AP) oscillation with eyes open and on Berg s scores between groups. A weak correlation was observed between strength and balance. Conclusion: The results suggest that the frail elderly present worse muscle performance in lower extremity and worse postural balance compared to the pre-frail elderly. There were correlations between muscle performance and balance impairments in these elderly, but several variables are also involved in maintaining postural balance

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Introduction: The SPPB provides information about physical function and is a predictor of adverse events in the elderly. Frailty is a multidimensional syndrome that increases susceptibility to diseases and disability. However it may be possible to prevent or postpone frailty if is identified early. Our objective is to analyze SPPB s ability in screening for frailty a community-dwelling young elderly from cities with distinct socioeconomic conditions. Methods: Data were originated from community dwelling adults (65-74 years old) in Canada (Saint Bruno; n = 60) and Brazil (Santa Cruz; n = 64). SPPB was used to assess physical performance. Frailty was defined as the presence of ≥ 3 of these criteria: weight loss, exhaustion, weakness, mobility limitation and low physical activity. One point was given for each criterion met, totalizing a frailty score ranged from 0 to 5. The Linear Regression and Receiver Operating Characteristics analyses were performed to evaluate the SPPB s screening ability. Results: Mean age was 69.48, 10.0% of the Saint Bruno s sample and 28.1% of Santa Cruz s were frail (p = 0.001), the SPPB score means were 9.6 and 8.5 respectively (p = 0.01). SPPB correlated with the frailty score (R2 = 0.33), with better results for Saint Bruno. A cutoff of 9 in SPPB had good sensitivity and specificity in discriminating frail from non frail in Saint Bruno (AUC = 0.81) but showed fair results in Santa Cruz (AUC = 0.61). Conclusion: The SPPB has moderate ability in predicting frailty among older adult s population, and is an useful test to identify people with good functionality and low frailty when SPPB scores are ≥9

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Introduction: The frailty in the elderly is the result of a complex interplay between many social and clinical factors involved in its genesis. Although there is an understanding of its association with increased risk of adverse clinical outcomes, still it is unclear whether this syndrome can be aggravated due to lack of social support. So, the objective of this study was to analyze the association between social support and frailty syndrome in elderly community residents. Materials and methods: Observational analytical cross-sectional study, with a sample of 300 elderly living in the city of Natal-RN. Were collected informations about socialdemographic, economics and physical health data. The Social support was assessed by the status of cohabitation; marital status; contact frequency and diversity rate; received and given attendance frequency rate; and Map Minimum Relations of the Elderly. The frailty was assessed using the following criteria: unintentional weight loss, weakness, low physical activity, exhaustion and Slowness. To observe any possible associations, we performed the Pearson chi-square test, the Student t test and multivariate analysis using binary logistic regression, adopting a significance level of 5%. Results: It was observed that there were no associations of frailty with the social support variables, except for housekeeping mode (p = 0.046) of the MMRI. For the sociodemographic, economic, physical health and social support data, only age (p <0.001), sedentary lifestyle (p = 0.002) and poor perceived health (p = 0.001) were the ones that remained in the logistic regression model, with strong association for the presence of frailty. Conclusion: Among the variables related to social support, only to help with housekeeping was significantly associated with frailty. However, more studies need to be developed to characterize the social vulnerability, as well as health services need to recognize the importance of social support as an integral part of care for the elderly

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Introdução: Vem sendo crescente o número de pesquisas que buscam o entendimento das relações entre os desfechos adversos à saúde e as concentrações do cortisol salivar, o qual é um marcador de estresse biológico. O cortisol parece seguir dois estágios de resposta: em situações de baixo/moderado estresse ocorre ativação do eixo Hipotálamo-Pituitária-Adrenal, aumentando o nível do cortisol, entretanto, quando o estresse persiste, o eixo HPA parece tornar-se hipoativo. A sintomatologia depressiva parece ter relação com as concentrações do cortisol, no entanto, essa relação é controversa na literatura. Objetivo: Analisar a relação entre sintomatologia depressiva e concentrações do cortisol em uma amostra de idosos do Nordeste brasileiro, residentes na comunidade. Métodos: Estudo observacional analítico, de caráter transversal, em uma amostra de 256 idosos (≥ 65 anos), residentes na comunidade. A sintomatologia depressiva foi avaliada pela versão brasileira da Center for Epidemiologic Studies-Depression Scale (≥ 16) e as concentrações do cortisol através da coleta salivar (ao acordar, 30 minutos após acordar, 60 minutos após acordar, às 15 horas e antes de dormir), além de medidas compostas. Como co-variáveis foram avaliadas condições sociodemográficas e de saúde. Para análise das medidas do cortisol entre idosos com e sem presença da sintomatologia depressiva, e entre os sexos, foi realizado o teste t de Student. Para verificar as diferenças entre as medidas do cortisol em cada curva foi utilizada a Análise de Variância (ANOVA) de medidas repetidas, com teste post-hoc de Bonferroni. Resultados: Houve diferença significativa para a medida de cortisol salivar ao acordar, entre os idosos com presença e ausência da sintomatologia depressiva (p=0,04). Não houve significância em relação ao sexo. Na análise entre as medidas de cada curva, foi observado que nos idosos com sintomatologia depressiva a 1ª medida não teve diferença significativa em relação à 2ª e 3ª medidas. Além disso, não houve diferença significativa da 4ª medida em relação à 5ª, demonstrando um maior nível noturno de cortisol para os idosos com sintomatologia depressiva, sem declínio, com aspecto plano da curva. Conclusão: Parece existir relação entre sintomatologia depressiva e hipocortisolismo. Entretanto, no Brasil, as condições adversas de vida podem levar ao estresse crônico e serem fatores fortes suficientes para sobrepor maiores diferenças que pudessem existir em relação à presença da sintomatologia depressiva

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Cytogenetic studies have been revealing a great diversity not detected, until then, in several families of fishes. Many of these groups, especially those that exhibit great diversity, like Perciformes and Siluriformes, possess species with difficult morphologic characterization, called cryptic species, commonly detected through karyotypic analyses, which reveals outstanding interespecific variations with relationship to the number and its chromosomal structures. Thus, the present work intends to contribute for the cytogenetic knowledge of marine and brackish fish species, because they peculiar life habits and by lack of cytogenetic data of your genetic aspects. Therefore, cytogenetic studies were developed in a species of Apogonidae (Perciformes), two species of sea catfishes of the family Ariidae (Siluriformes) and brackish fish Paurachenipterus galeatus (Siluriformes, Auchenipteridae), through C banding, Ag-NOR, use of base-specific flourochromes (DAPI and CMA3), as well as FISH (Fluorescent in situ hybridization) using ribosomal DNA probes 5S and 18S. The present results contribute to a better understanding of the processes of differentiation patterns and chromosome evolution in these groups. The use of other approaches (the morphology and molecular tools) will allow a larger understanding of the genetic and biological diversity of the Brazilian ichthyofauna.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Cytogenetics analyses in fish are important because they compose a private group among the vertebrates, occupying a central position in the animal evolution. The Perciforms Order, dominant in the marine and freshwater environment, it constitutes a model potentially useful in the genetic evaluation of populations, as well as in the understanding of its evolutionary processes. In spite of this, cytogenetics studies in this great group is scarce, above all for the inhabitants of sandy bottom and pelagics habits. The present work proposed to contribute for the cytogenetic characterization of nine species of fish marine of sandy bottom of the coast of Rio Grande do Norte (Brazil), identifying the evolutionary patterns related to the karyotype in these species and the existence of filogenetics affinities between them and other Perciformes. The animals were collected in the beaches of the Redinha, Ponta Negra and Búzios (Coast of Rio Grande do Norte) and in Saint Peter and Saint Paul Archipelago. Later on they were submitted to the cytogenetics technical that consist of mitotic estimulation, obtaining of mitotics chromosomes, proceeded by techniques of conventional coloration (Giemsa) and chromosomic bands (Ag-RONs and C band). Diploid number and fundamental number equal to 48 were observed in most of the species: Menticirrhus americanus, Ophioscion punctatissimus, Pareques acuminatus (Sciaenidae); Chloroscombrus chrysurus (Carangidae); Echeneis sp. 2 (Echeneidae); Archosargus probatocephalus (Sparidae) and Orthopristis ruber (Haemulidae). Trachinotus goodei (NF=52) (Carangidae) and Echeneis sp. 1 (Echeneidae) (NF=54) presented variation in NF, staying constant a diploid number equal to 48. RONs was situated in pericentromeric position in whole the scianids, and in the species Echeneis sp. 2 (22° pair), O. ruber and A. probatocephalus (1° pair), coinciding with great heterocromatics blocks in M. americanus (1° pair), P. acuminatus (2° pairl) and O. ruber (1° pair). RONs was also located in the telomeric area of the short arm of the 5° and 11° acrocentrics pairs in T. goodei, 4° and 19° pairs of C. chrysurus, 1° pair (sm) of Echeneis sp. 1. The C band detected centromeric blocks in most of the chromosomes of the species of Sciaenidae, Carangidae and Echeneidae, with great blocks in A. probatocephalus (4° pair). Heterocromatic blocks in telomeric areas in submetacentrics of Echeneis sp. 1, and pericentromerics in M. americanus (1° and 8° pairs), O. punctatissimus (1° pair) and P. acuminatus (2° pair) were also observed. It is noticed a marked conservatism cromossomic in the species of the family Scianidae and Haemulidae in what says respect to the number of acrocentrics chromosomes and the location of RONs. Even so it is outstanding the presence of heterocromatinization events during the karyotypic evolution of this family. Already in the families Sparidae and Carangidae, the obtained results reaffirm examples of small variations structural resultants of inversion and translocation Robertsonian, as important mechanisms of diversification karyotipical, as well as a pattern numerical evolutionary conserved, also observed in representatives of Echeneidae of Atlantic in relation to Pacific. The presence of RONs multiple, observed in the species T. goodei and C. chrysurus seems to represent a character derived in the family Carangidae. The results for the species O. ruber and A. probatocephalus suggest the presence of possible geographical or climatic barriers among populations of NE of Brazil in relationship the one of the SE