25 resultados para Coexistência

em Universidade Federal do Rio Grande do Norte(UFRN)


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How ecologically similar species are able to coexist has always generated great interest in the scientific community. Classical niche theory predicts that species coexistence is only possible when they segregate in at least one dimension of the ecological niche, thus leading to ecological differentiation among species. However, recent work has shown that species that are more similar in some ecological traits are the ones more prone to be able to coexist (environmental filter). The knowledge of how these forces act shaping ecological communities can reveal co-existence strategies, providing important information for management and conservation of the species. This study tested these hypotheses using a pair of coexisting species of Herpsilochmus, H. pectoralis and H. sellowi. In this study I use high resolution (50 x 50 m) ecological niche models to Identify which environmental factors best predict species occurrence. Next, I calculate the overlap in habitat use by species and build null models to test the hypothesis of spatial niche segregation. In addition, I obtain the selectivity parameters of habitat use to test whether the species H. pectoralis (larger body size) is less selective than H. sellowi (smaller body size) as stated in the literature for other species. The results reject the ecological equivalence among species, revealing that the species of Herpsilochmus explore the habitat differently, having different environmental niches. The hypothesis of environmental filter was not observed in my analysis, the observed overlap in habitat use among species was lower than expected by chance. Evidence that Herpsilochmus are spatially segregating reinforces the hypothesis of interspecific competition as the predominant force in the selection of microhabitat of the species. However, more data and experiments are necessary to state categorically that the observed pattern is a result of current or past competition

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The increasing demand for Internet data traffic in wireless broadband access networks requires both the development of efficient, novel wireless broadband access technologies and the allocation of new spectrum bands for that purpose. The introduction of a great number of small cells in cellular networks allied to the complimentary adoption of Wireless Local Area Network (WLAN) technologies in unlicensed spectrum is one of the most promising concepts to attend this demand. One alternative is the aggregation of Industrial, Science and Medical (ISM) unlicensed spectrum to licensed bands, using wireless networks defined by Institute of Electrical and Electronics Engineers (IEEE) and Third Generation Partnership Project (3GPP). While IEEE 802.11 (Wi-Fi) networks are aggregated to Long Term Evolution (LTE) small cells via LTE / WLAN Aggregation (LWA), in proposals like Unlicensed LTE (LTE-U) and LWA the LTE air interface itself is used for transmission on the unlicensed band. Wi-Fi technology is widespread and operates in the same 5 GHz ISM spectrum bands as the LTE proposals, which may bring performance decrease due to the coexistence of both technologies in the same spectrum bands. Besides, there is the need to improve Wi-Fi operation to support scenarios with a large number of neighbor Overlapping Basic Subscriber Set (OBSS) networks, with a large number of Wi-Fi nodes (i.e. dense deployments). It is long known that the overall Wi-Fi performance falls sharply with the increase of Wi-Fi nodes sharing the channel, therefore there is the need for introducing mechanisms to increase its spectral efficiency. This work is dedicated to the study of coexistence between different wireless broadband access systems operating in the same unlicensed spectrum bands, and how to solve the coexistence problems via distributed coordination mechanisms. The problem of coexistence between different networks (i.e. LTE and Wi-Fi) and the problem of coexistence between different networks of the same technology (i.e. multiple Wi-Fi OBSSs) is analyzed both qualitatively and quantitatively via system-level simulations, and the main issues to be faced are identified from these results. From that, distributed coordination mechanisms are proposed and evaluated via system-level simulations, both for the inter-technology coexistence problem and intra-technology coexistence problem. Results indicate that the proposed solutions provide significant gains when compare to the situation without distributed coordination.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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Intending to explain the extraordinary lizard coexistence levels found in Australian deserts, Morton & James (1988) figured out a hypothesis which defends that the termite diversity would bring about lizard radiation. This study aims to verify the validation of that hypothesis in Caatinga lizard assemblages. This study also objectives verifying if the termite defense mechanisms influence their consuming levels by lizards and if this pattern differs between different lizard lineages. Termites were collected using a standardized sampling protocol of termites. Besides using haphazard sampling, we collect lizards with 108 pitfall traps in each area. Intending to check the linkage between the termite and lizard assemblages, the lizard stomach contents were analyzed and then a canonical correspondence analysis was performed. The presence of nonrandom patterns of diet overlap among the lizard species was also examined. Aiming to check if the defense mechanisms of termite influence their consuming pattern by lizards it was performed a laboratory experiment where termite with different defense mechanisms were offered to lizards of two different lineages. We verified that lizard assemblages do not consume termites according to termite abundance in ecosystems. Furthermore, mean niche overlap lizard species did not differ significantly from that expected by chance. We found that termite chemical defense mechanism does influence the termite s pattern consuming by lizards. These results do not corroborate premises which support Morton & James hypothesis (1988) and point out that lizard do not chose termites based on their abundance, but, trying to avoid consuming termites which exhibit chemical defense mechanisms. This defense mechanism, however, may not be the only explanation to patterns of termite s consuming by lizards.

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Understand the origin, maintenance and the mechanisms that operate in the current biodiversity is the major goal of ecology. Species ecology can be influenced by different factors at different scales. There are three approaches about the ecological differences between species: the first brings that differences result from current processes on niche characteristics (e.g. diet, time, space); the second that species differences are explained by random patterns of speciation, extinction and dispersion, the third that historical events explain the formation and composition of species in communities. This study aims to evaluate the influence of phylogenetic relationships in determining ecological characteristics in amphibians (globally) and test with that, if ecological differences between species of frogs are the result of ancient pre-existing differences or as result of current interactions. Another objective of this study is to verify if ecological, historical or current characteristics determine the size of species geographical distribution. The diet data for analysis of trophic ecology were collected from published literature. We performed a non-parametric MANOVA to test the existence of phylogenetic effects in diet shifts on frogs history. Thus, it is expected to know the main factors that allow the coexistence of anuran species. We performed a phylogenetic regression to analyze if niche breadth, body size and evolutionary age variables determine the size of the geographical distribution of amphibians in the Amazon. In the present study, new contributions to knowledge of major ecological patterns of anurans are discussed under a phylogenetic perspective

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Successive curricular changes that occurred in professional education altered pedagogical practices, and these practices being developed by means of integrating projects, at Centro Federal de Educação Tecnológica de Sergipe (CEFET-SE), between 2001 and 2003, originated some questions which became the study object of this thesis. We search for theoretical support mainly in GEPEM research (GEPEM/UFRN) works and practices in order to analyze elements that emerged from this pedagogical practice. To do so, we take as main reference the research of qualitative approach. We developed documents analysis, interviews, considering three aspects: the scenery where these changes took place, the conception and implementation of the Integrating Projects for what, we ask support in pedagogy of projects studies and principles of interdisciplinary, and contextualization as curriculum structuring elements. This research brought out some difficulties, conflicts and possible consensus in developing the methodological strategies for the Projects. In this process of coexistence of the traditional and the new, of an unavoidable distance between what was thought and what was effectively done, elements for a new pedagogical practice emerged. This could be noticed in terms of participative work, formative moments, teacher s autonomy related to the pedagogical work. A new door could be open to the possibilities of taking conscience of accepting the differences and oneself autoexperimentation. These are the possibilities that make men, not being mere information deposit, can dialog and transform, producing his existence by this means. In the present case, the existence of being teacher, the build himself in the time of possibilities

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This dissertation aims to develop a software applied to a communication system for a wireless sensor network (WSN) for tracking analog and digital variables and control valve of the gas flow in artificial oil s elevation units, Plunger Lift type. The reason for this implementation is due to the fact that, in the studied plant configuration, the sensors communicate with the PLC (Programmable and Logic Controller) by the cables and pipelines, making any changes in that system, such as changing the layout of it, as well as inconveniences that arise from the nature of the site, such as the vicinity s animals presence that tend to destroy the cables for interconnection of sensors to the PLC. For software development, was used communication polling method via SMAC protocol (Simple Medium Access ControlIEEE 802.15.4 standard) in the CodeWarrior environment to which generated a firmware, loaded into the WSN s transceivers, present in the kit MC13193-EVK, (all items described above are owners of Freescale Semiconductors Inc.). The network monitoring and parameterization used in its application, was developed in LabVIEW software from National Instruments. The results were obtained through the observation of the network s behavior of sensors proposal, focusing on aspects such as: indoor and outdoor quantity of packages received and lost, general aspects of reliability in data transmission, coexistence with other types of wireless networks and power consumption under different operating conditions. The results were considered satisfactory, which showed the software efficiency in this communication system

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The construction of a mapping of the practices of reading and writing printed and digital texts, declared by graduating students from the Bachelor s degree in Science and Technology (BCT), has provided us the analysis of the course they are making in such a socio-historical moment characterized by the revolution of the post-paper. In this sense, the general objective of this research is to understand how that construction works under the point of view of those graduating students. For this, our reflection has been guided by the search of answers for some questions which have presented to us: what reading and writing conceptions BCT graduating students have; what reading and writing practices those collaborators develop; what collections they declare to have access to; what differences they declare to have between printed and digital reading and writing along the different social roles they develop; what the reader/writer identity relations of those collaborators are. To achieving the plausible answers, we have gathered a corpus composed by texts of three genres of the argument order: academic profiles (or self-portrait), opinion articles and argumentative letters. Besides, we have made semi-structured interviews and questionnaires in the online tool of the Google Docs. The methodology which supports this academic work is the qualitative research (SIGNORINI; CAVALCANTI, 1998)of ethnographic direction (THOMAS, 1993; ANDRÉ, 1995) in Applied Linguistics (CELANI, 2000; MOITA-LOPES, 2006) and the theoretical contribution comes from the bakhtinian perspective of language conception (BAKHTIN [1929] 1981); the socio-historical writing construction (LÉVY, 1996; CHARTIER, R., 1998, 2002, 2007; COSCARELLI, 2006; CHARTIER, A., 2007; ARAÚJO, 2007; COSCARELLI; RIBEIRO, 2007; XAVIER, 2009; MARCUSCHI; XAVIER, 2010); from the studies of the pedagogy of the writing (GIROUX, 1997); from the literacy studies understood as sociocultural practice, plural and situated (TFOUNI, 1988; KLEIMAN, 1995; TINOCO, 2003, 2008; OLIVEIRA; KLEIMAN, 2008), from the studies about identity in postmodernity (HALL, 2003; BAUMAN, 2005). The results of the analysis have pointed at a multiplicity of reading/writing practices of printed and digital texts developed by the BCT graduating students due to the coexistence of the modality printed and that one derived from the new mobile devices. In that multiplicity, the prevalent idea of the collaborators is that there is a continuum between printed texts and digital texts (not a dichotomy), since the option of reading/writing printed texts or digital ones is always linked to specific communication situations, which involve participants, objectives, strategies, values, (dis)advantages, besides (re)creation of discursive genres in function of the mobile devices to which those collaborators have access in the different spheres of activities that they participate. All of that has caused a deep intersection in the identity traces of college students readers/writers in the 21st century which cannot be ignored by academic formation

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A fundamentação metafísica do direito a que nos propomos a esclarecer na filosofia de Kant assume não somente uma análise de temas jurídicos. Temos uma questão filosófica de fundo a tratar: a justiça é possível? Tal indagação não é o tema do texto, mas o que está pressuposto. A análise kantiana, de certo modo, assume metafisicamente a possibilidade da justiça a partir do conceito de liberdade. Mas, com base na liberdade, demonstra a possibilidade da justiça na ética e no direito. A dissertação é composta por três capítulos. No primeiro capítulo, partindo da reconstrução inicial do conceito de liberdade na Crítica da Razão Pura, descrevemos a construção do conceito cosmológico de liberdade transcendental a partir do terceiro conflito antinômico e de sua solução na Dialética Transcendental. Feito isso, descrevemos o conceito de liberdade no capítulo do Cânon da Razão Pura e discutimos o problema de como compatibilizar liberdade transcendental e liberdade prática. No segundo capítulo, fazemos uma análise da distinção entre a legislação moral e a legislação jurídica das ações humanas partindo da análise da liberdade prática interna (moral) e distinguindo-a da liberdade prática externa (ou jurídica). Nesse contexto, desenvolvemos os pressupostos de uma metafísica do direito, tomando como ponto de partida o conceito de liberdade e o imperativo categórico como princípio da autonomia da vontade, base normativa para a lei universal do direito. No terceiro capítulo, a partir da relação entre ética e direito, reconstruímos o conceito de Direito e esclarecemos o fundamento da legitimidade da coerção a partir do princípio normativo de coexistência das liberdades individuais. Analisamos também os aspectos fundamentais do direito que derivam deste princípio, tal como os conceitos de Contrato Originário, Estado, Lei, Coerção,bem como a proposta kantiana de uma paz universal com base numa legislação internacional. No fim, discutimos o aspecto metafísico presente no fundamento do Direito

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This study evaluated the spatial, time and alimentary niches of Tropidurus hispidus and Tropidurus semitaeniatus in sympatry in a caatinga of Rio Grande do Norte, Brazil, as well as their foraging and termoregulatory behaviors, the activity body temperature and their reproductive and fat body cycles. Monthly excursions, from October 2006 to May 2008, were conducted at the Ecological Station of the Seridó (ESEC Seridó), Serra Negra do Norte municipality, using specific methodology for investigation of the aforementioned objectives. The two species presented similarities in space niche use, mainly in rocky habitat, however they differed in vertical microhabitat use with T. hispidus using a larger vertical microhabitat range. In the dry season the time of activity of both species was bimodal. In the wet season T. semitaeniatus showed a unimodal activity period, while T. hispidus maintained an bimodal activity period. In terms of importance in the diet, to both species, Hymenoptera/Formicidae and Isoptera predominated during the dry season. In the wet season, although Hymenoptera/Formicidae had larger importance among the prey items, lizards opportunistically predated on Lepidoptera larvae, Coleoptera larvae/adults and Orthoptera nymphs/adults. The foraging intensity revealed differences between the species, mainly in the wet season, when T. semitaeniatus was more active than T. hispidus. The mean activity body temperature of T. semitaeniatus was significantly higher than that of T. hispidus. The thermoregulatory behavior showed that during the dry season T. hispidus and T. semitaeniatus spent more time in shade or under filtered sun. In the wet season, T. hispidus did not show differences in the amount of time spent among the light exposure locations, however T. semitaeniatus spent most of their time exposed to direct sun or filtered sun. The reproductive cicle of T. hispidus and T. semitaeniatus occurred from the middle of the dry season to the beginning of the wet season. In both species, female reproductive activity was influenced by precipitation, whereas males exhibited spermatozoa in their testes throughout the year, and their reproductive activity was not related with any of the climatic variables analysed. In the two species, the fat storage varied inversely with reproductive activity, and there was no difference in fat body mass between females and males. We concluded that the segregation between T. hispidus and T. semitaeniatus in this caatinga area occurs in vertical space use, in the largest vagility of T. hispidus in microhabitat use and larger range size of their alimentary xviii items. Additionally, significant seasonal differences in relation to the activity period, body temperature, and foraging and termoregulatory behaviors between these two Tropidurus species facilitate their coexistence.

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Tropidurus semitaeniatus and Tropidurus hispidus are lizard species that are widely distributed in Brazil. The former is endemic to the Caatingas, where they live in syntopy with the latter, which is distributed in other ecosystems and biomes. In this work, diet was evaluated including seasonal variations as well as foraging behavior, to determine the importance of these factors in the structure of these populations and the coexistence of these species in syntopy. No significant difference was found in diet composition between the two species, although T. hispidus feed on larger preys than do T. semitaeniatus; this fact, along with the different foraging behavior in the rainy season, are ecological factors that contribute to the syntopic coexistence of these species in the Caatinga area studied

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As part of a broader project, Diversity and Distribution Patterns of Floristic and Faunistic composition of remnants of Potiguar s Atlantic Forest, as subsidies to conservation , that subsidizes a group of institutional research, This study aimed to evaluate the structure of the assemblage of lizards a remnant of the of the northern Atlantic Forest, identifying ecological factor (s) that contribute to the coexistence of sympatric species. Additionally, we studied the thermal ecology and thermoregulatory behavior of umbrophily and heliophily species live the Parque Estadual Mata da Pipa (PEMP), a remnant of Atlantic forest located in the Tibau do Sul municipality of, Rio Grande do Norte State, Brazil. It is one of the largest remnants of the Atlantic Forest and has an area of approximately 290 ha. The study was performed by four excursions to the field for 20 days each, when active search and pitfalls traps were used to record and colleted specimens in different habitats of the area. We recorded the presence of 19 species of lizards, of which seven are typical of forest areas, three are endemic Atlantic Forest, these two northern and one are new record for the Rio Grande do Norte. The use of resources, the results showed that phylogenetically related species do not always use a similar way the resources available; the feeding niche was the segregated component of the species that overlapped extensively in the use of space and vice versa. To examine the thermal ecology and thermoregulatory behavior of Kentropyx calcarata and Coleodactylus natalensis, we recorded the clocal temperature (Tc), oh the substrate (Ts) and of the air (Ta) to investigate what of these are the source of heat more important to the temperature s body of these lizards. Behavioral observations were conducted to analyze strategies to optimize the acquisition of heat. The air temperature explained most strongly to variation in body temperature of K. calcarata, while the temperature of the substrate to C. natalensis. As for the behavioral observations, they confirmed that K. calcarata is an active thermoregulatory; C. natalensis is a passive thermoregulatory.

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School psychology can be considered a growing professional field in Brazil, in spite of the difficulties concerning both the role of the psychologists in the schools and the restrictions of the labor market. Professional training is one of the most problems faced by the area. The present study is an attempt to investigate the conceptions of school psychology and the practice of the school psychologists inside de educational agencies, from the point of view of the professional training, expressed by curricular supervised training. The reason for this choice was the important role played by supervised training in the process of professional training. To carry out this study, supervised training reports written in the 1980s and the 1990s used in the student evaluation process were examined. As the main results, we point out the co-existence during the 1980-decade of two models of psychological practice: the clinical and the educational, with the dominance of the first one. During the 1990-decade, we can observe the co-existence of the same models with the dominance (but not the hegemony) of the educational model, as shown by the activities of the students. In the 1980s, for instance, the most common activities were observation of the children (45.9%), teachers guidance (40.5%) and psychodiagnostic (37.8%). In the 1990s, the main activities were participation in staff briefings (66.6%), parents guidance (58.0%), teachers guidance (50.0%) and students counseling (41.6%). Aspects related to the importance of professional training - represented by curricular supervised training - to the professional practice are discussed

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Many studies on environmental ecosystems quality related to polycyclic aromatic hydrocarbons (PAH) have been carried out routinely due to their ubiquotus presence worldwide and to their potential toxicity after its biotransformation. PAH may be introduced into the environmet by natural and anthropogenic processes from direct runoff and discharges and indirect atmospheric deposition. Sources of naturally occurring PAHs include natural fires, natural oil seepage and recent biological or diagenetic processes. Anthropogenic sources of PAHs, acute or chronic, are combustion of organic matter (petroleum, coal, wood), waste and releases/spills of petroleum and derivatives (river runoff, sewage outfalls, maritime transport, pipelines). Besides the co-existence of multiples sources of PAH in the environmental samples, these compounds are subject to many processes that lead to geochemical fates (physical-chemical transformation, biodegradation and photo-oxidation), which leads to an alteration of their composition. All these facts make the identification of the hydrocarbons sources, if petrogenic, pyrolytic or natural, a challenge. One of the objectives of this study is to establish tools to identify the origin of hydrocarbons in environmental samples. PAH diagnostic ratios and PAH principal component analysis were tested on a critical area: Guanabara Bay sediments. Guanabara Bay is located in a complex urban area of Rio de Janeiro with a high anthropogenic influence, being an endpoint of chronic pollution from the Greater Rio and it was the scenario of an acute event of oil release in January 2000. It were quantified 38 compounds, parental and alkylated PAH, in 21 sediment samples collected in two surveys: 2000 and 2003. The PAH levels varied from 400 to 58439 ng g-1. Both tested techniques for origin identification of hydrocarbons have shown their applicability, being able to discriminate the PAH sources for the majority of the samples analysed. The bay sediments were separated into two big clusters: sediments with a clear pattern of petrogenic introduction of hydrocarbons (from intertidal area) and sediments with combustion characteristics (from subtidal region). Only a minority of the samples could not display a clear contribution of petrogenic or pyrolytic input. The diagnostic ratios that have exhibited high ability to distinguish combustion- and petroleum-derived PAH inputs for Guanabara Bay sediments were Phenanthrene+Anthracene/(Phenanthrene+Anthracene+C1Phenanthrene); Fluorantene/(Fluorantene+Pyrene); Σ (other 3-6 ring PAHs)/ Σ (5 alkylated PAH series). The PCA results prooved to be a useful tool for PAH source identification in the environment, corroborating the diagnostic indexes. In relation to the temporal evaluation carried out in this study, it was not verified significant changes on the class of predominant source of the samples. This result indicates that the hydrocarbons present in the Guanabara Bay sediments are mainly related to the long-term anthropogenic input and not directly related to acute events such as the oil spill of January 2000. This findings were similar to various international estuarine sites. Finally, this work had a complementary objective of evaluating the level of hydrocarbons exposure of the aquatic organisms of Guanabara Bay. It was a preliminary study in which a quantification of 12 individual biliar metabolites of PAH was performed in four demersal fish representing three different families. The analysed metabolites were 1-hydroxynaphtalene, 2-hidroxinaphtalene, 1hydroxyphenanthrene, 9-hydroxyphenanthrene, 2-hydroxyphenanthrene, 1hydroxypyrene, 3-hidroxibiphenil, 3- hydroxyphenanthrene, 1-hydroxychrysene, 9hydroxyfluorene, 4-hydroxyphenanthrene, 3-hydroxybenz(a)pyrene. The metabolites concentrations were found to be high, ranging from 13 to 177 µg g-1, however they were similar to worldwide regions under high anthropogenic input. Besides the metabolites established by the used protocol, it was possible to verified high concentrations of three other compounds not yet reported in the literature. They were related to pyrolytic PAH contribution to Guanabara Bay aquatic biota: 1-hydroxypyrine and 3-hydroxybenz(a)pyrine isomers