119 resultados para Clotilde Sabattini


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Colección: Naturaleza y Parques Nacionales (serie Educación Ambiental)

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A low resolution coupled ocean-atmosphere general circulation model OAGCM is used to study the characteristics of the large scale ocean circulation and its climatic impacts in a series of global coupled aquaplanet experiments. Three configurations, designed to produce fundamentally different ocean circulation regimes, are considered. The first has no obstruction to zonal flow, the second contains a low barrier that blocks zonal flow in the ocean at all latitudes, creating a single enclosed basin, whilst the third contains a gap in the barrier to allow circumglobal flow at high southern latitudes. Warm greenhouse climates with a global average air surface temperature of around 27C result in all cases. Equator to pole temperature gradients are shallower than that of a current climate simulation. Whilst changes in the land configuration cause regional changes in temperature, winds and rainfall, heat transports within the system are little affected. Inhibition of all ocean transport on the aquaplanet leads to a reduction in global mean surface temperature of 8C, along with a sharpening of the meridional temperature gradient. This results from a reduction in global atmospheric water vapour content and an increase in tropical albedo, both of which act to reduce global surface temperatures. Fitting a simple radiative model to the atmospheric characteristics of the OAGCM solutions suggests that a simpler atmosphere model, with radiative parameters chosen a priori based on the changing surface configuration, would have produced qualitatively different results. This implies that studies with reduced complexity atmospheres need to be guided by more complex OAGCM results on a case by case basis.

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Muscle coenzyme Q(10) (CoQ(10) or ubiquinone) deficiency has been identified in more than 20 patients with presumed autosomal-recessive ataxia. However, mutations in genes required for CoQ(10) biosynthetic pathway have been identified only in patients with infantile-onset multisystemic diseases or isolated nephropathy. Our SNP-based genome-wide scan in a large consanguineous family revealed a locus for autosomal-recessive ataxia at chromosome 1q41. The causative mutation is a homozygous splice-site mutation in the aarF-domain-containing kinase 3 gene (ADCK3). Five additional mutations in ADCK3 were found in three patients with sporadic ataxia, including one known to have CoQ(10) deficiency in muscle. All of the patients have childhood-onset cerebellar ataxia with slow progression, and three of six have mildly elevated lactate levels. ADCK3 is a mitochondrial protein homologous to the yeast COQ8 and the bacterial UbiB proteins, which are required for CoQ biosynthesis. Three out of four patients tested showed a low endogenous pool of CoQ(10) in their fibroblasts or lymphoblasts, and two out of three patients showed impaired ubiquinone synthesis, strongly suggesting that ADCK3 is also involved in CoQ(10) biosynthesis. The deleterious nature of the three identified missense changes was confirmed by the introduction of them at the corresponding positions of the yeast COQ8 gene. Finally, a phylogenetic analysis shows that ADCK3 belongs to the family of atypical kinases, which includes phosphomositide and choline kinases, suggesting that ADCK3 plays an indirect regulatory role in ubiquinone biosynthesis possibly as part of a feedback loop that regulates ATP production.

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Introduction N-Acetylcysteine (NAC) may have efficacy in treating tobacco use disorder (TUD) by reducing craving and smoking reward. This study examines whether treatment with NAC may have a clinical efficacy in the treatment of TUD. Methods A 12-week double blind randomized controlled trial was conducted to compare the clinical efficacy of NAC 3 g/day versus placebo. We recruited 34 outpatients with therapy resistant TUD concurrently treated with smoking-focused group behavioral therapy. Participants had assessments of daily cigarette use (primary outcome), exhaled carbon monoxide (COEXH) (secondary outcome), and quit rates as defined by COEXH<6 ppm. Depression was measured with the Hamilton Depression Rating Scale (HDRS). Data were analyzed using conventional and modified intention-to-treat endpoint analyses. Results NAC treatment significantly reduced the daily number of cigarettes used (Δ mean±SD = -10.9 ± 7.9 in the NAC-treated versus -3.2 ± 6.1 in the placebo group) and COEXH (Δ mean± SD = -10.4 ± 8.6 ppm in the NAC-treated versus -1.5 ± 4.5 ppm in the placebo group); 47.1% of those treated with NAC versus 21.4% of placebo-treated patients were able to quit smoking as defined by COEXH<6 ppm. NAC treatment significantly reduced the HDRS score in patients with tobacco use disorder. Conclusions These data show that treatment with NAC may have a clinical efficacy in TUD. NAC combined with appropriate psychotherapy appears to be an efficient treatment option for TUD.

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No mundo, hoje, tudo está em movimento. Pessoas, objetos, valores, informação e imagens circulam cada dia mais intensa e extensamente em um ambiente social fluido, em rede e de riscos. Quando a mobilidade torna-se parte importante da experiência cotidiana e os deslocamentos físicos, geográficos, virtuais ou imaginativos tomam a frente nas relações e alteram radicalmente os modos de vida em todas as esferas - social, cultural, política e econômica -, nesse momento uma cultura da mobilidade se impõe e envolve a todos em novas possibilidades e experiências, assim como, em novos constrangimentos, riscos e discursos que devem ser estudados. O cada dia mais intenso imbricamento entre a cultura da mobilidade e o discurso publicitário constitui a base que sustenta a tese e que delineia as duas premissas fundamentais do estudo: a primeira, de que as coisas do mundo chegam até o sujeito apesar de sua imobilidade, por meio dos objetos, das informações e das imagens que circulam globalmente; e, a segunda premissa, de que a despeito de seu caráter comercial, persuasivo e de vendas, a publicidade também pode ser encarada como um bem cultural que expressa a cultura da qual faz parte. É na articulação destas duas premissas que reside o interesse primordial e o objeto de estudo da pesquisa: ao considerar o fazer publicitário como representação da sociedade, investigar, a partir da perspectiva do Paradigma das Novas Mobilidades, como o movimento é expresso discursivamente na publicidade das marcas globais. A interpretação do discurso publicitário global teve como objetivo validar a hipótese de que há um consumo de (i)mobilidade sendo feito quando o indivíduo sai em busca de objetos que, a partir de sua disponibilidade (ready-to-handness) e potencial de uso em relação ao ambiente (affordance), suportem sua (i)mobilidade cotidiana com certa estabilidade e menor risco. O locus da investigação é o Brasil e o estudo focou sua análise nos 32 anos relativos ao período de 1982 a 2014. Foram selecionados anúncios de marcas veiculados na revista Veja durante o período de três Copas do Mundo FIFA: de 1982, na Espanha; de 1998, na França; e de 2014, no Brasil, que cobrem o período proposto pela pesquisa.

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The use of non-human primates in scientific research has contributed significantly to the biomedical area and, in the case of Callithrix jacchus, has provided important evidence on physiological mechanisms that help explain its biology, making the species a valuable experimental model in different pathologies. However, raising non-human primates in captivity for long periods of time is accompanied by behavioral disorders and chronic diseases, as well as progressive weight loss in most of the animals. The Primatology Center of the Universidade Federal do Rio Grande do Norte (UFRN) has housed a colony of C. jacchus for nearly 30 years and during this period these animals have been weighed systematically to detect possible alterations in their clinical conditions. This procedure has generated a volume of data on the weight of animals at different age ranges. These data are of great importance in the study of this variable from different perspectives. Accordingly, this paper presents three studies using weight data collected over 15 years (1985-2000) as a way of verifying the health status and development of the animals. The first study produced the first article, which describes the histopathological findings of animals with probable diagnosis of permanent wasting marmoset syndrome (WMS). All the animals were carriers of trematode parasites (Platynosomum spp) and had obstruction in the hepatobiliary system; it is suggested that this agent is one of the etiological factors of the syndrome. In the second article, the analysis focused on comparing environmental profile and cortisol levels between the animals with normal weight curve evolution and those with WMS. We observed a marked decrease in locomotion, increased use of lower cage extracts and hypocortisolemia. The latter is likely associated to an adaptation of the mechanisms that make up the hypothalamus-hypophysis-adrenal axis, as observed in other mammals under conditions of chronic malnutrition. Finally, in the third study, the animals with weight alterations were excluded from the sample and, using computational tools (K-means and SOM) in a non-supervised way, we suggest found new ontogenetic development classes for C. jacchus. These were redimensioned from five to eight classes: infant I, infant II, infant III, juvenile I, juvenile II, sub-adult, young adult and elderly adult, in order to provide a more suitable classification for more detailed studies that require better control over the animal development

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Regarding the growing number of human beings with physical and mental pathologies associated to different stressor agents, attempts are being made to validate animal models with a close phylogenetic resemblance to man, to study stress response. Callithrix jacchus has been widely used in biomedical research, including on stress, but there is scarce information in the literature about how individual and social factors modulate stressor response in this species. This study uses 4 approaches to investigate the response of male and female adult C. jacchus, under situations of stress, and in the first we show evidence of the importance of this animal as an experimental model in research involving the hypothalamus-pituitary-adrenal axis. And we investigate if sex and baseline cortisol levels modulate the behavioral and hormonal response to separation. In two additional approaches investigate if type of social support (co-specific parent or non-parent) and social rank interfere in behavioral and hormonal when the animal are exposure to a new environment, paired with a co-specific (F2), exposure of the animal to a new environment, isolated (F3) or during reunion (F4). Finally, we also investigated the androgen levels in the males, with a focus on the challenge hypothesis, referring to environmental responsiveness and male-male exposure to relatives and non-relatives of C. jacchus. It was observed that: (1) the baseline cortisol of the animal is predictive of cortisol reactivity at separation; (2) males and females do not show dimorphism in the response of cortisol to stressors, although the females have higher baseline levels of this hormone and exhibit higher frequencies of anxiety-related behaviors; (3) only social support provided by relatives proved to be effective in buffering the cortisol response. In behavioral terms this response was dimorphic, showing that only the male dyads displayed an attenuated response to stress; (4) the males showed differences in cortisol levels as a function of social rank and study phases, whereas in the females no such alterations were observed. The males with indefinite dominance hierarchy (IDH) had reduced cortisol in F2 and F4, while the IDH females showed an increase in F3 and F4; (5) the males of relative and non-relative dyads did not exhibit variations in androgen levels as a function of a new environment. These results, taken together, (a) corroborate the use of C. jacchus as a good animal model for stress-related studies, given that they exhibit similar behavioral and physiological alterations to those of human beings in response to stressor agents; (b) point to the importance of considering individual and social modulating factors during experiments with stressors; (c) provide more reliable comparison parameters in studies where these primates are used as animal models, and (d) show that androgens vary as a function of genetic proximity (relative or non-relative) when the animals are faced with physical and social environmental challenges, thus providing important information for studying the challenge hypothesis in this species

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The use of animal models in biomedical research is ever increasing. Models that use primates might also have advantages in terms of low maintenance costs and availability of biological knowledge, thereby favoring their use in different experimental protocols. Many current stress studies use animal models at different developmental stages since biological response differs during ontogeny. The aims of this study were to perform a detailed characterization of the developmental stages of common marmosets (Callithrix jacchus), a very important animal model used in biomedical research. Ten subjects, 6 females and 4 males, were followed from birth to initial adult age (16 months). Behavioral and fecal collection for measurement of adrenal (cortisol) and sex (progesterone, estradiol and androgens) hormones took place twice a week during the first month of life and once a week for the remainder of the study. Behavior was observed for 30 minutes in the morning (0700-09:00h) and afternoon (12:00-14:00h). Behavioral profile showed changes during ontogeny, characterizing the 4 developmental stages and the respective phases proposed by Leão et al (2009).. Differentiation of developmental stages was considered using the onset, end, change and stabilization of the behavioral profile parental care (weaning and carrying), ingestion (solid food), affiliation (social grooming) and autogrooming, agonism (scent marking and piloerection) and play behavior and endocrine profile. Infant weaning and carrying terminated within the infantile stage and the peak of solid food ingestion was recorded in the infantile III phase. Receiving grooming was recorded earlier than grooming performed by the infant and autogrooming. The first episode of scent marking was recorded in the 4th week and it was the least variable behavior, in terms of its onset, which, in almost all animals, was between the 5th and 7th week of life. Solitary play and play with the twin started around the 7th week and play with other members of the group started 8 weeks later. Sex hormone secretion started to differ from basal levels between the 21st and 23rd week of life, in males and females, suggesting that puberty occurs simultaneously in both sexes. Basal cortisol, even at an early age, was higher in females than in males. However, cortisol was not correlated with the juvenile stage, as expected, since this stage corresponds to the transition between infancy and adult age and most behaviors are intensified by this time. The behavioral and endocrine profile of subadult animals did not differ from that of the adults. These results provide more detailed parameters for the developmental process of C. jacchus and open new perspectives for the use of experimental approaches focused on the intermediate ontogenetic phases of this species

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The cats (Felis catus) were domesticated about 9,500 years ago due to the advent of agriculture, being used to control the pests that devastated the food harvested. These animals went through an artificial selection and over generations and millennia had their behavior and morphology changed by humans. This process of domestication by man gave rise to a special ability, the understanding of human pointing gestures, clearly noticed while we feed our pets. Our goal in this study was to assess the comprehension of pointing gestures by cats and also verify the influence that social interactions exerts on the development of this ability. We found that experimental subjects from both groups, solitary animals and social animals, were able to follow human indication in order to find hidden food. However, social interaction had no effect on cats performances. The ability tested here probably evolved during the process of domestication of this species, and social interaction seems to exert little or no influence upon its expression

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Considering the Brazilian current context, where many children are in institutional shelter waiting for adoption, the aim of this study was to know the meaning that sheltered children (whose families had already lost their custody or were in the process of losing it, at the moment of the field work) gave to their adoption condition. The research was carried out with three children in the shelter where they lived, in Natal, Rio Grande do Norte, Brazil. The field work took six months approximately. In order to meet the objective of this research, individual procedures were structuralized using figures and drawing material. With these procedures the children could speak directly or indirectly about the application of the legal measure of institutional shelter, about their lives before the application of this legal measure and what happened since then, and their original families and future perspectives. The content of the procedures was tape recorded and registered in the field work diary. The analysis of the corpus occurred with the Thematic Content Analysis, considering the theoretical methodological perspective of the Net of Meanings approach. The analysis of the corpus showed the ambiguity of the children, who consider good to live in the institution where they are, recognizing the responsibility of the original caregivers for their sheltered condition and, at the same time, they miss their relatives and wish to be with them. The subjects recognize the perspective of adoption and imagine it in a positive way. However, when the children were questioned about what could happen to them in the future, they said that they did not know, expressing uncertainty concerning their destinations

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Objective - To determine effects of reducing the diameter of the left ventricle of dogs by plication of the left ventricular free wall. Animals - 8 healthy adult mixed-breed dogs. Procedure - Left lateral thoracotomy and a T-shaped pericardiotomy were performed. The free wall of the left ventricle was imbricated with 3 interrupted transfixing sutures applied in a horizontal mattress pattern, using 3-0 polypropylene suture assembled on a straight cutting needle. Surgeons were careful to avoid the coronary vessels. Echocardiography was performed 24 hours before and 48 hours after surgery. Electrocardiography was performed before and 1, 2, 7, 15, 21, 30, and 60 days after surgery. Results - Echocardiographic measurements revealed that the diameter of the left ventricle was reduced by a mean of 23.5%. Electrocardiography revealed ventricular premature complexes 24 hours after surgery that regressed without treatment during the first week after surgery. Conclusions and Clinical Relevance - Plication of the left ventricular free wall of dogs can reduce end-diastolic and end-systolic dimensions of the left ventricle. The technique is simple and does not require cardiopulmonary bypass. According to Laplace's law, the reduction of cardiac diameter leads to reduction on free-wall tension and may improve left ventricular function in dilatated hearts. Thus, additional studies involving dogs with dilated cardiomyopathy should be conducted.

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Purine nucleoside phosphorylase (PNP) catalyzes the phosphorolysis of the N-ribosidic bonds of purine nucleosides and deoxynucleosides. A genetic deficiency due to mutations in the gene encoding for human PNP causes T-cell deficiency as the major physiological defect. Inappropriate activation of T-cells has been implicated in several clinically relevant human conditions such as transplant tissue rejection, psoriasis, rheumatoid arthritis, lupus, and T-cell lymphomas. Human PNP is therefore a target for inhibitor development aiming at T-cell immune response modulation. In addition, bacterial PNP has been used as reactant in a fast and sensitive spectrophotometric method that allows both quantitation of inorganic phosphate (Pi) and continuous assay of reactions that generate P i such as those catalyzed by ATPases and GTPases. Human PNP may therefore be an important biotechnological tool for P i detection. However, low expression of human PNP in bacterial hosts, protein purification protocols involving many steps, and low protein yields represent technical obstacles to be overcome if human PNP is to be used in either high-throughput drug screening or as a reagent in an affordable P i detection method. Here, we describe PCR amplification of human PNP from a liver cDNA library, cloning, expression in Escherichia coli host, purification, and activity measurement of homogeneous enzyme. Human PNP represented approximately 42% of total soluble cell proteins with no induction being necessary to express the target protein. Enzyme activity measurements demonstrated a 707-fold increase in specific activity of cloned human PNP as compared to control. Purification of cloned human PNP was achieved by a two-step purification protocol, yielding 48 mg homogeneous enzyme from 1 L cell culture, with a specific activity value of 80 U mg -1. © 2002 Elsevier Science (USA). All rights reserved.

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António de Morais Silva publicou em 1789 a 1ª edição de seu Diccionario da Lingua Portugueza e em 1813, a sua 2ª edição, ambas em Lisboa. Partindo da relação entre gramática e dicionário, obras que se completam no ensino e aprendizagem de uma língua, estudamos neste trabalho a projeção gramatical do autor na elaboração dos verbetes da 2ª edição do Diccionario, numa tentativa de demonstrar que Morais, influenciado pelas idéias reformistas do Século das Luzes em Portugal, inovou em termos lexicográficos e gramaticais, registrando essas inovações e também algumas críticas às gramáticas de seu tempo, no interior dos verbetes de sua obra lexicográfica.