42 resultados para Novos vínculos
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
Mira and R Coronae Borealis (R CrB) variable stars are evolved objects surrounded by circumstellar envelopes (CSE) composed of the ejected stellar material. We present a detailed high-spatial resolution morfological study of the CSE of three stars: IRC+10216, the closest and more studied Carbon-Rich Mira; o Ceti, the prototype of the Mira class; and RY Sagitarii (RY Sgr), the brightest R CrB variable of the south hemisphere. JHKL near-infrared adaptive optics images of IRC+10216 with high dynamic range and Vband images with high angular resolution and high depth, collected with the VLT/NACO and VLT/FORS1 instruments, were analyzed. NACO images of o Ceti were also analyzed. Interferometric observations of RY Sgr collected with the VLTI/MIDI instrument allowed us to explore its CSE innermost regions (»20 40 mas). The CSE of IRC+10216 exhibit, in near-infrared, clumps with more complex relative displacements than proposed in previous studies. In V-band, the majority of the non-concentric shells, located in the outer CSE layers, seem to be composed of thinner elongated shells. In a global view, the morphological connection between the shells and the bipolar core of the nebulae, located in the outer layers, together with the clumps, located in the innermost regions, has a difficult interpretation. In the CSE of o Ceti, preliminar results would be indicating the presence of possible clumps. In the innermost regions (.110 UA) of the CSE of RY Sgr, two clouds were detected in different epochs, embedded in a variable gaussian envelope. Based on a rigorous verification, the first cloud was located at »100 R¤ (or »30 AU) from the centre, toward the east-north-east direction (modulo 180o) and the second one was almost at a perpendicular direction, having aproximately 2£ the distance of the first cloud. This study introduces new constraints to the mass-loss history of these kind of variables and to the morphology of their innermost CSE regions
Resumo:
VANTI, Nadia. Links hipertextuais na comunicação científica: análise webométrica dos sítios acadêmicos latino-americanos em Ciências Sociais. Porto Alegre, 2007. 292 f. Tese (Doutorado em Comunicação e Informação) – Universidade Federal do Rio Grande do Sul. Porto Alegre, 2007.
Resumo:
Dopamine (DA) is known to regulate both sleep and memory formations, while sleep plays a critical role in the consolidation of different types of memories. We believe that pharmacological manipulation of dopaminergic pathways might disrupt the sleep-wake cycle, leading to mnemonic deficits, which can be observed in both behavioral and molecular levels. Therefore, here we investigated how systemic injections of haloperidol (0.3 mg/kg), immediately after training in dark and light periods, affects learning assessed in the novel object preference test (NOPT) in mice. We also investigated the hippocampal levels of the plasticity-related proteins Zif-268, brain-derived neurotrophic factor (BDNF) and phosphorylated Ca2+/calmodulin-dependent protein kinases II (CaMKII-P) in non-exposed (naïve), vehicle-injected controls and haloperidol-treated mice at 3, 6 and 12 hours after training in the light period. Haloperidol administration during the light period led to a subsequent impairment in the NOPT. In contrast, preference was not observed during the dark period neither in mice injected with haloperidol, nor in vehicle-injected animals. A partial increase of CaMKII-P in the hippocampal field CA3 of vehicle-injected mice was detected at 3h. Haloperidol-treated mice showed a significant decrease in the dentate gyrus of CaMKII-P levels at 3, 6 and 12h; of Zif-268 levels at 6h, and of BDNF levels at 12h after training. Since the mnemonic effects of haloperidol were only observed in the light period when animals tend to sleep, we suggest that these effects are related to REM sleep disruption after haloperidol injection
Resumo:
Nowadays, composite resins are the direct restorative materials more important in dental clinical performance, due to their versatility and aesthetic excellence. Bis-GMA (2,2-bis[4(2-hydroxy-3-metacryloxypropoxy)phenil]propane) is the base monomer more frequently used in restorative composite resins. However, this monomer presents some disadvantages, such as high viscosity and two aromatic rings in its structure that can promote allergic reactions to the humans. In this work, the main purpose was to synthesize new monomers from glycidyl methacrylate to use in dental restorative materials. Structural characterization of the monomers was carried out through FTIR and NMR 1H, and eight composites were produced from the new monomers, by addition of silane-treated alumino silicate particles (inorganic filler) and a photocuring system (camphorquinone and ethyl 4-dimethylaminebenzoate). The composites were analyzed by environmental scanning electronic microscopy and the water sorption and solubility, compressive strength and elastic modulus were determined. A commercial composite resin [Z100 (3M)] was used to comparison effect. The new composites presented general characteristics similar to the commercial ones; however, they didn t present the properties expected. This behavior was attributed to the lower degree of monomer reaction and to the granulometry and size distribution of the mineral filler in the polymeric matrix
Resumo:
Sugar esters are substances which possess surfactant, antifungical and bactericidal actions and can be obtained through two renewable sources of raw materials: sugars and vegetable oils. Their excellent biodegradability, allied to lhe fact that they are non toxic, insipid, inodorous, biocompatible, no-ionic, digestible and because they can resist to adverse conditions of temperature, pH and salinity, explain lhe crescent use of these substances in several sections of lhe industry. The objective of this thesis was to synthesize and characterize surfactants and polymers containing sugar branched in their structures, through enzymatic transesterification of vinyl esters and sugars, using alkaline protease from Bacillus subtilis as catalyst, in organic medium (DMF).Three types of sugars were used: L-arabinose, D-glucose and sucrose and two types of vinyl esters: vinyl laurate and vinyl adipate. Aiming to reach high conversions from substrates to products for a possible future large scale industrial production, a serie of variables was optimized, through Design of Experiments (DOE), using Response Surface Methodology (RSM).The investigated variables were: (1) enzyme concentration; (2) molar reason of substrates; (3) water/solvent rale; (4) temperature and (5) time. We obtained six distinct sugar esters: 5-0-lauroyl L-arabinose, 6-0-lauroyl D-glucose, 1'-O-lauroyl sucrose, 5-0-vinyladipoyl L-arabinose, 6-0-vinyladipoyl D-glucose and 1 '-O-vinyladipoyl sucrose, being lhe last three polymerizable. The progress of lhe reaction was monitored by HPLC analysis, through lhe decrease of sugar concentration in comparison to lhe blank. Qualitative analysis by TLC confirmed lhe formation of lhe products. In lhe purification step, two methodologies were adopted: (1) chromatographic column and (2) extraction with hot acetone. The acylation position and lhe chemical structure were determined by 13C-RMN. The polymerization of lhe three vinyl sugar esters was possible, through chemical catalysis, using H2O2 and K2S2O8 as initiators, at 60°C, for 24 hours. IR spectra of lhe monomers and respective polymers were compared revealing lhe disappearance of lhe vinyl group in lhe polymer spectra. The molar weights of lhe polymers were determined by GPC and presented lhe following results: poly (5-0-vinyladipoyl L-arabinose): Mw = 7.2 X 104; PD = 2.48; poly (6-0-vinyladipoyl D-glucose): Mw = 2.7 X 103; PD = 1.75 and poly (1'-O-vinyladipoyl sucrose): Mw = 4.2 X 104; PD = 6.57. The six sugar esters were submitted to superficial tension tests for determination of the critical micelle concentrations (CMC), which varied from 122 to 167 ppm. Finally, a study of applicability of these sugar esters, as lubricants for completion fluids of petroleum wells was' accomplished through comparative analysis of lhe efficiency of these sugar esters, in relation to three commercial lubricants. The products synthesized in this thesis presented equivalent or superior action to lhe tested commercial products
Resumo:
Industrial activities, oil spills and its derivatives, as well as the incomplete combustion of fossil fuels have caused a great accumulation of hydrocarbons in the environment. The number of microorganisms on the planet is estimated at 1030 and prokaryotes the most abundant. They colonized diverse environments for thousands of years, including those considered extreme and represent an untapped source of metabolic and genetic diversity with a large biotechnological potential. It is also known that certain microorganisms have the enzymatic capacity to degrade petroleum hydrocarbons and, in many ecosystems, there is an indigenous community capable of performing this function. The metagenomic has revolutionized the microbiology allowing access uncultured microbial communities, being a powerful tool for elucidation of their ecological functions and metabolic profiles, as well as for identification of new biomolecules. Thus, this study applied metagenomic approaches not only for functional selection of genes involved in biodegradation and emulsification processes of the petroleum-derived hydrocarbons, but also to describe the taxonomic and metabolic composition of two metagenomes from aquatic microbiome. We analyzed 123.116 (365 ± 118 bp) and 127.563 sequences (352 ± 120 bp) of marine and estuarine metagenomes, respectively. Eight clones were found, four involved in the petroleum biodegradation and four were able to emulsify kerosene indicating their abilities in biosurfactants synthesis. Therefore, the metagenomic analyses performed were efficient not only in the search of bioproducts of biotechnological interest and in the analysis of the functional and taxonomic profile of the metagenomes studied as well
Resumo:
The aim of this work was to perform the extraction and characterization of xylan from corn cobs and prepare xylan-based microcapsules. For that purpose, an alkaline extraction of xylan was carried out followed by the polymer characterization regarding its technological properties, such as angle of repose, Hausner factor, density, compressibility and compactability. Also, a low-cost and rapid analytical procedure to identify xylan by means of infrared spectroscopy was studied. Xylan was characterized as a yellowish fine powder with low density and poor flow properties. After the extraction and characterization of the polymer, xylan-based microcapsules were prepared by means of interfacial crosslinking polymerization and their characterization was performed in order to obtain gastroresistant multiparticulate systems. This work involved the most suitable parameters of the preparation of microcapsules as well as the study of the process, scale-up methodology and biological analysis. Magnetic nanoparticles were used as a model system to be encapsulated by the xylan microcapsules. According to the results, xylan-based microcapsules were shown to be resistant to several conditions found along the gastrointestinal tract and they were able to avoid the early degradation of the magnetic nanoparticles
Resumo:
Since Demirjian's system of estimating dental maturity was first described, many researchers from different countries have tested its accuracy among diverse populations. Some of these studies have pointed out a need to determine population-specific standards. In Brazil, the Northeast region is the one that most suffers the negative impact of exodus, specially related to the increase of abandoned children in the cities. The aim of this study was to test the accuracy of Demirjian's system for assessing the dental maturity of northeastern Brazilian children, so as to present a scale for maturity score conversion into dental age developed specifically for this population. This could be used for forensic, anthropological and legal matters, and also as a model for other countries attempting to formulate their own conversion scales. Panoramic radiographs of 1,491 children (821 females and 670 males), aged 7 to 13 years, from Ceará state, northeast Brazil, were assessed by a single observer to determine dental age (DA) according to Demirjian's system. The mean percentage of intra-observer agreement was 86.6%, with a mean Cohen's Kappa coefficient of 0.67 (substantial agreement). The DA was compared by paired t-test to subjects' chronological age (CA). The differences between CA and DA in all age groups were statistically significant (p<0.0001), demonstrating a great advancement in DA among Brazilians. Scatter plots were drawn for both genders, and the data were fitted to a growth curve, y = 100/ (1 + e-a(x b)). Graphs corresponding to the 50th percentile curves were produced. A table with new values for the conversion of maturity score into dental age for northeastern Brazilian children is presented. The great advancement in DA, as obtained by Demirjian's system in this population, justified the determination of specific scores for dental maturity assessment
Resumo:
The dynamics of social fights in Santa Maria district, Aracaju, represents, in this study, the search process for understanding and analyzing the articulations of the social movements, their victories, and their ways of practicing politics, it proposes, therefore, a search for explanations and to reflect upon some issues such as: what are the dynamics of social fights and victories of the popular social movements is Santa Maria District? How do they work to solve their problems and to answer the demands along with the institutions that are responsible for the public policies in the district? With the answers to these and other questions, an analysis of the population‟s fights with the support of local social movements will be conducted. It will be done based on the historical-critical perspective of the social movements within the context of social live, through a qualitative approach based on semi=structured interviews applied to people who are close observers of the district‟s reality, and on the analysis of News contents that were published in two newspapers from Aracaju in previous years, especially from 2004 to 2008. In face of the material studied about the News from newspapers and the contents of magazines, it is evident that the local popular movements began as a new way of practicing politics that was characterized by a reproductive practice of the status quo. There is one perspective left for the population from Santa Maria District, that they demand the local leadership to take actions in face of their dynamic of fights
Resumo:
Esta dissertação é um estudo sobre as representações e práticas sociais relativas à construção da conjugalidade homoafetiva e o direito de reconhecimento. Nesse contexto, são analisados os embates ideológicos decorrentes das tentativas de redefinição das representações e práticas sociais relativas à família e a conjugalidade, em sua feição heterocêntrica, a partir das disputas em torno do reconhecimento social e jurídico das uniões homoafetivas, desencadeadas no contexto da sociedade brasileira, a partir da apresentação, no Congresso Nacional, do Projeto de Lei n° 1.151/95, da Deputada Marta Suplicy, que disciplina a união civil entre pessoas do mesmo sexo
Resumo:
This work has the main goal on the recognition of the inherent value of nonhuman animals, under the constitutional framework. It is presented the main philosophical formulations of the current pattern of behavior that rules the relationship between man and animals: first those that have excluded animals from moral consideration and then the thinkers which do have included, in some way, in order to elucidate the origin of the anthropocentric thought over the natural world. In this way, the analysis these thinkers that have included animals in moral consideration will contribute to a paradigm change from the anthropocentric view, initiating legal debates. It will be made a simplified analysis of different philosophical and legal points of view that have been demonstrating the posture in which the human beings have been dealing with the environment, with the replacement of the anthropocentric thinking for the biocentric view, in which life becomes the center of existence. Life is life, no matter whether it is human or not, has a value in itself, and must be protected and respected by the legal system. Then, it will be analized the constitutionalization of the nonhuman animal dignity in comparative law; the infraconstitutional legislation which concerning the intrinsic value of all life forms and, finally, the 1988 Constitution. It will be advocated for non-human animals the condition of subjects, presenting some cases that the Habeas Corpus was used in animal defense. In this new Brazilian Habeas Corpus theory of for apes the argument of genetic proximity was used in order to overcome the literal meaning of natural person to achieve hominids in order to assure the fundamental right of physical freedom. It is realized that the fact that the great apes being recognized as a person does not preclude the possibility of other living beings be recognized as subjects of law. In this way, animals can be considered non-human subjects of law, according to the theory of depersonalized entities and may enjoy a legal category that allows a respect for existential minimum, and can hold constitutional fundamental rights
Resumo:
This work is a case study to investigate the dynamics of the historians thought as they produce a knowledge about the history of the area measurement systems as forms of historical expressions and representations. We refer to some of the ideas of David Bohm (1989, 1992, 1994, 1996) to support our theoretical understanding about the operation of thought. We chose a period that is recognized by the theorists as the origin of the geometrical thought -embracing the knowledge developed by the Egyptians, Babylonians, Chinese, Hindus, Greeks and Romans- and is referred to as containing a cycle in the development of this knowledge, described as beginning, apogee and decline. We assume this history, as told by the theorists, as a version that we organize and tell with the help of three sets of categories. The first refers to the elements that take part in the measurement practices; the second refers to the historians understanding about the development of the scientific knowledge. This exercise allowed us to extract the theorists main beliefs, that we criticized in the light of the knowledge about Cubação (Dal Pian, 1990). We stress the importance of the methodological approach adopted in this study to the teaching of Geometry and its history
Resumo:
This work has its genesis in the life of a teacher. It contemplates the report of a great story that expresses the political will of anonymous people who sought/seek to overcome challenges and prejudices, a joint effort to make real the right to literacy. The reported story was developed in the Pedagogic Clinic Teacher Heitor Carrilho, Natal-RN which, concerned about the sentence of 'unable to learn the written language' attributed to children and young public school students, decided to invest in overcoming prejudices and fight against school failure of these underprivileged. The problem that motivated the study was thus set up: What particularities characterize a pedagogical practice which aims to teach literacy to children and youth from public schools, considered not capable of learning the written language? What theoretical and methodological procedures are shown as a boost to literacy in the development of a pedagogical practice systematically targeted to reflect the perspective of educating those students in public schools? Aiming to answer these questions, we conducted a qualitative research having as methodology, Life Stories and Research/Formation. For the construction of the data, it was decided to use the participative observation, semi-structured interviews and document analysis. Guided by the principles of content analysis the data analysis was built, from which emerged two categories: theoretical and methodological procedures aligned to the major axes of literacy and Procedures of the specific theoretical and methodological fundamentals of literacy. As subsets of the transverse procedures others were seized: didactic-pedagogic procedures; social affective procedures. Regarding these ones, the research shows the importance of the teacher to build a relationship of listening to the students and their families in order to organize the pedagogical work, looking at multiple dimensions of the subject: the intellect, the creative, the affective, moral, noting that between the methodology and didactics or as part of it, the links built represent great opportunities to promote literacy. Regarding the specific procedures, others were built: procedures that emphasize oral communication, procedures that favor writing and procedures that privilege reading. Under these procedures, the results of research show that you can only promote literacy if the teacher provides the students effective conditions of understanding the principles of alphabetical notation from the use of various kinds of texts, leading them to comprehend and use them in different contexts. Therefore, instructors must meet the learners' prior knowledge, their language, and the learning real needs that will bring new challenges consistent with their possibilities. The research confirms the importance of the Educational Support extra school. However, it is essential to emphasize that it is a function of the school to promote literacy for all students in the early years of schooling. It is recorded, however, that for the implementation of this desire, we must break the school model characterized by a rigid tradition, in which there is only room for those who learn the content taught in a minimum time. Unfortunately, despite the discourse of inclusion and ensuring the right to education, the school remains exclusive and selective separating the school learning of interpersonal relations and social integration and performance. On the one hand, research showed the difficulties of conducting studies and/or strategies that address the particularities of children and young people believed not capable of learning. On the other hand, the political commitment and motivation have increased the perception that it is possible to mitigate the existing deficits in the educational context, beginning with the everyday teaching practice, in which new knowledge can be learned, methodologies can be improved and, despite everything, the educational success can be built
Resumo:
This work, named Teaching conditions: a study in municipal schools of Currais Novos RN (2009 to 2012) aims to analyze the status of teaching in schools in the municipality of Currais Novos RN in the period ranging from 2009 - 2012, considering infrastructure, initial and continued training and intensification and casualization of teaching factors in the context of the 1990s educational reformations. It, also, assumes that teaching is a constitutive part of capitalist society, and has been reconfigured with based on the new requirements demanded by the labor market. In order to conduct this study the considered data included the survey research Teaching Work in Basic Education in Brazil (2009 to 2010) , held in seven Brazilian states being: Pará, Rio Grande do Norte, Minas Gerais, Goiás, Paraná, Santa Catarina and Espírito Santo. Specifically selected for deepening of the study, there were schools in the municipality of Currais Novos in which semi-structured interviews were performed with teachers of the said municipality. This research is constituted of a qualitative and quantitative approach whose survey instruments adopted were, namely: documental research, literature review, interviews and surveys. The obtained data analysis allows us to infer that the teaching work performed by teachers in the states which participated in the survey has been influenced the changes in the labor market and educational reformations and has been taking on characteristics such as flexibility, tendency to precariousness and intensification; and this trend is also present in schools that were surveyed in the municipality of Currais Novos. As pertaining to the teachers conditions in classroom, these signs are more evident, considering that they had their duties and responsibilities extended beyond the classroom environment. The data also show that in general working conditions of teachers in national, state and local levels are unprofitable and heterogeneous, increasingly deepening the gap between school units and education networks. Therefore, the implantation of public policies that enhance the teaching work and improve their working conditions in all dimensions that directly interfere in their work are crucial
Resumo:
It is about a study of an exploratory/descriptive type with a qualitative approach whose aim was to analyze the actuation of nursing technicians in Family Health Strategy (FHS), taking into consideration the defined attributions by the Ministry of Health (MH). Thus, it was sought to identify what activities they carry out, the difficulties encountered, what contributed to their professional performance, and what vision they have about FHS and about themselves in the context. Based on the assumption that the practice of Nursing Technician is not still geared to completeness and that the developed actions by this professional are predominantly individual and curative. We know that FHS proposes the work organization as a team, with territory definition, prioritization of promotion actions, protection and recovery of the individual/family/community health, choosing as a central point the establishment of entails between the professionals and the same ones. However, the team work pass through interdisciplinary, tying and competence, starting making the difference in the way of thinking and doing health. To the accomplishment of this study were interviewed twenty one Nursing Technicians of Family Health Units from Sanitário Oeste district in Natal-RN, using semistructured instrument. From the analysis, three empiric categories emerged: starting from the first, The reality of a dream: what FHS is for the Nursing Technician, we obtained two classifications: one inherent to the own conception they have about FHS, nominated The realization of a dream in the possible and another that corresponds to what they think about FHS, while project that doesn't take place fully, denominated of The beauty of a dream that doesn't take place. The second category was The FHS: a dream built in the daily of Nursing Technician treats of the day by day information of that professional; the activities they perform and how those are established. This created three other items, to know: The role of a Nursing Technician: a project that became routine; The pre-determined role of a Nursing Technician: the scale as factor of (non-)autonomy; and, Knowledge about the practice in FHS: challenges that are presented to the role of Nursing Technician. The third category, denominated of Charms and disenchantment in the beginning of a new practice, it is related to the facilities or difficulties in professional's actuation and how he sees himself in the context. From it emerged the "flowers" and the "thorns" found on the construction of a dream, which gave this study the title. The results indicate that, being considered the characteristics of researched professional category, it becomes fundamental the resizing of labor relations in FHS, being imperative that new glances is conducted, so that the way as those Nursing Technicians interacts with the families can become compatible, together with the team, as well as to return the attention for their possibilities and limits in face of the work process in FHS. Besides, it is necessary changes in the professional formation, so that it can guarantee the conceptual bases in the construction of new practices, seeking to answer to the model of current attention.