969 resultados para CNPQ::CIENCIAS BIOLOGICAS: BIOTECNOLOGIA
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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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The currently accepted model of sensory processing states that different senses are processed in parallel, and that the activity of specific cortical regions define the sensorial modality perceived by the subject. In this work we used chronic multielectrode extracellular recordings to investigate to which extent neurons in the visual and tactile primary cortices (V1 and S1) of anesthetized rats would respond to sensory modalities not traditionaly associated with these cortices. Visual stimulation yielded 87% of responsive neurons in V1, while 82% of S1 neurons responded to tactile stimulation. In the same stimulation sessions, we found 23% of V1 neurons responding to tactile stimuli and 22% of S1 neurons responding to visual stimuli. Our data supports an increasing body of evidence that indicates the existence multimodal processing in primary sensory cortices. Our data challenge the unimodal sensory processing paradigm, and suggest the need of a reinterpretation of the currently accepted model of cortical hierarchy.
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In the present work, we investigated behavioral changes associated with the increase in Zif268 protein expression within telencephalic areas of the tropical lizard Tropidurus hispidus that correspond to the mammalian hippocampus (HC). We used 13 male individuals of this species, collected at the Federal Agrotechnical School of Rio Grande do Norte, under SISBIO license number 19561-1. Four animals had their brains removed and were submitted to a Western blot with antibodies for the Zif268 protein. The remaining animals were separated in two different groups: a control group (n=4) and an exploration group (n=5). Animals from the exploration group were exposed to an enriched environment with many sensory cues novel to them. Control group animals stayed in the environment they were already habituated to. After 90 min from the onset of exposure to the new environment, animals from both groups were submitted to intracardiac perfusion with fixative, and the brains were removed, cryoprotected and frozen. After that, brains were sectioned at 20 μm and the sections were subjected to immunohistochemistry for the Zif268 protein. We verified that the Zif268 protein is likely conserved in the brain of T. hispidus, which showed antigenicity for the antibody anti-Zif268 made in mammals. In animals from the exploration group, we detected an increase of the Zif268 protein in the Septum, Striatum, Dorsoventricular Area and in cortical areas corresponding to the HC. This increase was proportional to the amount of environmental exploration, with maximum positive correlation in the hippocampal subareas Medial Cortex (R = 0.94 and p = 0.004) and Dorsomedial Cortex (R = 0.92 and p = 0.006). The data corroborate the notion that the reptilian hippocampus, as well as the mammalian HC, plays an important role in spatial exploration.
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Seeing colors can be advantageous, because they are an important signal for providing information about the environment, such as the location of food. However, not every animals sees these chromatic signals in the same way. In primates, the group of Plathyrrhini has polymorphic sex-linked vision with males always dichromats and dichromats or trichromats females. Studies indicate that trichromats during foraging would benefit by seeing better than dichromats ripe fruits against the green foliage background. On the other hand, dichromats appear to distinguish camouflaged insects better than trichromats. The marmoset (Callihtrix jacchus) is a neotropical primate species that have color vision polymorphism. This species establishes family groups with highly reproductive bias, with breeding females often having preferential access to food. This work aims to study whether the social context influences the foraging ability of camouflaged and red items in groups of C. jacchus. Four groups of captive marmosets were presented to four food tasks, involving difficult, easy, reddish and camouflaged food targets. Foods were presented in a concentrated and dispersed manner, to check whether there was monopolization of the resources by the dominant subjects and if this would affect the ability of individuals to find the food targets. Success was measured by latency to food acquisition and number of targets consumed. Males and females differed in their foraging success for camouflaged and reddish items, although this difference has not appeared in all situations and experimental conditions. In general males were more successful for detecting camouflaged items while females succeeded more in identifying reddish items. There were no differences in foraging success between individuals of different social status, however, there were differences in the success of consumption of food items for different situations when food was concentrate compared with dispersed food. Taken as a role, there was a greater difficulty in detecting food items when they were presented in concentrated arrangement, which is supposed to be related to a higher difficulty to approach and stay near the food. Although it appears that there was no direct competition seems to have group's indirect influence on the detection of food items and foraging success of individuals, affecting mainly those items more difficult to detect
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In the school environment is fundamental the knowledge about the sleep-wake cycle (SWC), because we find children and adolescents with excessive sleepiness and learning difficulties. Furthermore, teachers with high demand and with different work schedule, which may contribute to changes in SWC. The aim of this study was to describe the SWC of high school teachers in Natal/RN. Habits and knowledge about sleep, chronotype, SWC, daytime sleepiness, sleep quality and job satisfaction were described in 98 high school teachers from public and private school. These parameters were compared according to the characteristics of work, family structure and gender. Data collection was performed with the use of questionnaires in two stages: 1) "health and sleep" (general characterization of sleep habits), Horne & Ostberg questionnaire (characterization of chronotype), Epworth Sleepiness Scale and the Index of Pittsburg Sleep Quality, 2) The sleep diary for 14 days. From the results, we observe that the teachers woke up and went to bed earlier in the week and showed a reduction of time in bed around 42min comparing to weekend. This reduction in time in bed during the week was accompanied by an increase in nap duration on weekend. In addition the teachers woke up earlier on Saturdays than on Sundays, probably due to housework and leisure. The teachers' knowledge about sleep was low in relation to individual differences and effect of alcoholic beverages on sleep, and high in the consequences of sleep deprivation. The differences found in comparisons on the characteristics of work, family structure and gender were punctual, except concerning the work schedule. The teacher who started work in the morning and finished in the night, woke up earlier, went to bed later and had less time in bed, when compared to teachers who work only in two shifts. In addition, teachers with late chronotypes who begin the work in the morning had a greater irregularity in the wake up time compared to teachers with earlier and intermediate chronotypes. Half of teachers have excessive sleepiness, which was positive correlated with work dissatisfaction. In general, teachers showed IPSQ averages equivalent to poor sleep quality and the women showed worst averages. From the results, it is suggested that the SWC of teachers varies according to work schedule, leading to irregularity and partial sleep deprivation in the week, although these responses vary according to chronotype. These changes are accompanied by excessive daytime sleepiness and poor sleep quality. However, it is necessary to expand the sample to clarify the influence of variables related to work, family structure and gender together
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Mothers with good vitamin A nutritional status during gestation and lactation are better able to nourish and protect their infant with maternal milk. Our hypothesis is that women with more serum retinol have more retinol and secretory immunoglobulin A in colostrum. 190 healthy puerperal women from a Brazilian public maternity were recruited and divided according to the cutoff point for serum retinol (30 μg/dL). A number of the women was supplemented with 200000 UI (60 mg) of retinyl palmitate in the immediate postpartum. Serum and colostrum were collected on the 1st day postpartum and colostrum again on the following day. Retinol (serum and colostrum) was analyzed by HPLC and SIgA (colostrum) by turbidimetry. The mothers presented with adequate biochemical indicators of nutritional status, according to serum retinol (44.6 μg/dL). There were significant differences (p= 0.0017 and p= 0.043, respectively) in retinol and SIgA levels in the colostrum of mothers with serum retinol > 30 μg/dL and < 30 μg/dL. The concentration of SIgA in the colostrum of non-supplemented mothers on the 1st day postpartum was 822.6 mg/dL, decreasing after 24 hours to 343.7 mg/dL. Supplemented mothers showed levels of SIgA in colostrum of 498.9 mg/dL on the 2nd day postpartum (p= 0.00006). The colostrum of women with good vitamin A nutritional status had more retinol and SIgA. Additionally, maternal supplementation increases the levels of SIgA in colostrum. The higher levels of SIgA on the 1st day postpartum showed the importance of early breastfeeding, given that it provides considerable immunological benefits to newborn infants
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Food is essential for the survival of all animals. Its temporal availability is an important enviromental cue for the behavioral and physiological organization throughout the 24 hours of day in different species. Rats and mice, for example, show increased locomotion in the hours before food availability when it is presented in a recurrent manner, a behavior named foodanticipatory activity. Several lines of evidence indicate that this anticipation is mediated by a circadian oscillator. In this work, based on the hypothesis that pre- or post-ingestive humoral signals are involved in the entrainment process, we tested whether the daily intake of glucose is sufficient to induce anticipatory activity in rats. The rhythms of motor activity and central temperature were recorded in animals undergoing 10 days of temporal glucose (solution at 50%) or chow restriction in light-dark (LD) and constant darkness (DD). Animals under temporal glucose restriction increase motor activity and and central temperature in the hours preceding glucose availability and such aticipation is extremely similar to that observed in animals under temporal chow restriction. Glucose ingestion is, therefore, a sufficient temporal cue to induce anticipation in rats. It is possible that the increase in plasma glucose after food ingestion constitutes one of the signals involved in the behavioral entrainment process to food availability
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Four areas are known as of frequent usage by Guiana dolphins (Sotalia guianensis) in the south coast of Rio Grande do Norte state, northeast Brazil: Tabatinga, Pipa, Lagoa de Guaraíras and Baia Formosa. This extension of 40 km of shoreline is under increasing anthropogenic impacts due to continuous development of the coastal areas and vessel traffic. The objective of this study was to investigate aspects of population biology and habitat use of the population of Sotalia guianensis in the south coast of Rio Grande do Norte. It was applied the photo-identification technique and posterior methods of capture-recapture for population estimation (POPAN extension in MARK). The distribution, movement and site fidelity of the dolphins were analyzed trough the geographic information system (GIS) and group characteristics and behavior trough non-parametric statistics. Field work was conducted on board a 10m motor vessel from March 2008 to March 2009. Photo-identification effort was 329h with 113h of direct observation of the dolphins. The population estimatives for each area: Tabatinga: 75 (63-92); Pipa 105 (88-129); Lagoa de Guaraíras: 27 (18-54) e Baia Formosa: 112 (89-129) individuals. Total population estimative was: 223 (192 a 297). High site fidelity was detected for only part of the population (<15%) as low site fidelity and transients individuals were also detected (>20%). It was observed frequent movements between Tabatinga, Lagoa de Guaraíras and Pipa, but not Baía Formosa. This suggests a division in two communities along this shore extension: one in Pipa and other in Baía Formosa. Group size was small, most groups with up to 10 dolphins. The areas were use intensively, only in Lagoa de Guaraíras dolphins were not seen in all field trips. Lagoa de Guaraíras is an area used by small groups exclusively for foraging. In Tabatinga and Pipa dolphins concentrated close to the shore, in the inner sector of the area and the main activity is also foraging. Significant larger groups were seen in socializing behavior but there was no difference in group size between the inner and external sectors of the area. The presence of calves and juveniles were significant greater in the inner areas of Tabatinga and Pipa, confirming the hypothesis that these beaches are also used for parental care. In Baia Formosa dolphins concentrated in the outer sector and foraging was also predominant. Significant larger groups were seen in the outer sector, mainly engaged in mixed behaviors of travel/foraging, possibly in some kind of group foraging. Calves and juveniles were significant more present in the outer sector where group size was also larger. In general there was no difference in area usage and period of the day. Sotalia guianensis has characteristics that make the species vulnerable to human activities such as small population concentrated in patches of suitable habitats restrict to coastal areas. We hope that this study bring new information for the species and help for the adequate management of the area in order to assure the presence of the dolphins as well as its behavior pattern and gene flow betweencommunities.
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Food access, territory or reproductive partner can generate conflicts between individuals in many species with occurrence of aggressive behaviors. However some species respond less aggressively to intrusion by neighbors than non-neighbors in its territory to minimize the costs of continuous fight. This difference in aggression is called Dear Enemy Effect described in various vertebrates and invertebrates. To investigate if this phenomenon occurs in Dinoponera quadriceps (Hymenopetra, Formicidae) three colonies, two neighbors and one non-neighbor, were captured in its natural environment then transfered to the laboratory where we did experimental confrontation intra and inter colonies involving one pair of workers. We compared the behavioral frequency exhibited by each worker, the intensity and duration of the confrontation between a neighbor and a non-neighbor referring the place where they were collected. Our results revealed that Dear Enemy Effect does not apply to D. quadriceps due aggressive response is more intense and longest toward neighbor than non-neighbor, probably due intra specific competition, ecological factors and characteristic of the species
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
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The lost of phase relationship between rhythms and behaviour can, and often do, undesirable consequences. The purpose os study was to ascertain the effect of circadian desynchronization in T22 about metabolism of wistar rats. The subjects consisted of 24 animals separated in two groups: control (n=12) T24 with 8 weeks of aged and experimental group (n=12) T22, also with 8 weeks of aged. Both the groups were subject to register of locomotor actitivity, body temperature, body weight and food intake in all the experiment. And more, both the groups were subject to food deprivation, running in treadmill and forced swimming. The results show rhythm of locomotor activity and body temperature desynchronized. Dont exist diference in body weight between both the groups (T24 = 386,75±40,78g e T22 380,83±44,28g) . However, the food intake was different between the phases, light and dark, in intergroup and intragroup. The body temperature was not different in food deprivation. The same ocurred for running in treadmill and forced swimming. Since similar alterations occur in shift workers, it is proposed that the experimental paradigm presented in this manuscript is a useful model of shift work. That is, alterations in activity/rest cycles and consummatory behavior can affect the health of organism
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The genus Callithrix, like other marmosets, presents a cooperative breeding system, characterized by the contribution of parents and non-breeding individuals of the social group in the care of infants. This care is provided through lactation, transport, supervision of infants and food transfers. In this study, we investigated the care of offspring in Callithrix jacchus through the food transfers in family groups under conditions of abundance and scarcity of food resources. We also attempted to verify the relationship between the participation of individuals in the transport of infants and in the food sharing. We observed four families at the Núcleo de Primatologia of the Universidade Federal do Rio Grande do Norte, in a total of seven infants, six twins and a single infant. Each infant was observed twice a week, from 1st to 20th week of life using the methods focal continuous and focal instantaneous sampling with one minute intervals. The observations were carried by 10 minutes and beginning with the supply of food for each family. Two families were tested under conditions of scarcity of food resources (experimental condition) and two others were subjected to conditions of abundant food, both conditions with restricted access to food supply. The condition of food scarcity did not influence the rate of food sharing with the infants that, in general, was considered low. All shares observed were passive sharings. Only one family showed higher levels of food begging, probably due to the loss of the mother during the period of lactation of her offspring. In this family, the dominant and subadult males were primarily responsible for the food sharing. The experimental condition influenced the distance of infants in relation to food source, so the infants in families that received abundant food remained closer to the source. However, it is believed that the place of food consumption was not influenced by experimental condition. There was no relationship between the participation of individuals in the transport and food sharing with their young. Therefore, it is suggested that, in general, the transfer of food in C. jacchus is characterized by tolerance to the demands of caregivers, represented by the passive sharing. Rates of sharing with infants were low, probably due to intra-group competition for food generated by the experiment.
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The new Evolutionary Psychology (E. P.) paradigm has been trying to understand how the human beings make their decisions over time regarding the most diverse variables, always bearing in mind that such a cognitive process is due to a complex natural selection process that occurred millions of years ago. One of the main topics discussed by this new paradigm is the issue of parental investment, i.e., the care the parents provide to an offspring at the expense of the investment into a new one. The present work sought to integrate these two topics, trying to understand how some variables modulate the process of decision making in a sample of the city of Natal, Rio Grande do Norte state. It was investigated the hypothesis that the presence of both parents, along the individual development, could signal a more favorable environment, providing clues to the individual that he could assume a competitive position at the socio-biological market. His decisions, therefore, could be guided by long-term investments with aims to obtain more robust rewards. On the contrary, those who has suffered for some moment the absence of one the parents could develop theirselves in a not so competitive way, starting to choose immediate benefits - but lesser ones -, since the future would be less predictable due to their worse development conditions. This study involved 152 individuals from three higher education institutions, one of them being public and the others being private ones. In the results found, there was no difference between children of coupled parents and children of deceased or divorced parents concerning discount rates. The levels of hopelessness did not affect the discount rates of children of single parents when compared to children of coupled parents. Not having one of the parents because of divorce made the child to tend to present lower scores in the domain of social relations of WHOQOL - Bref, whilst the absence of the father by death made the scores lower in the domain of environment. The results indicate that loosing one of the parents along the development influences the individual's quality of life perception, but the measurement method of future discounting rates by means of financial choices is not sensitive to this variation
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The sleep patterns of students entering the university, is accompanied by many factors that can lead to changes in sleep habits, such as academic demands, new social opportunities, reduced parental care and irregular teaching schedules. The irregular pattern of sleep-wake cycle is usually accompanied by several daytime consequences, for example, reduced levels of motivation, performance, concentration, alertness and mood as well as increased fatigue and sleepiness.Thus, there are numerous reasons to support the fact that these students may suffer damage in their academic performance. The aim of this study was to evaluate the sleep-wake cycle (SWC) and cognition in medical students with different schemes teaching schedules. One group started classes at 08am, while the other started at 07am. We analyzed the data from 88 volunteers, 39 from each group. However, only those who participated in both stages of the study (n = 78) underwent cognitive testing. For subjective evaluation of the SWC was used questionnaires to check the quality of sleep, chronotype, daytime sleepiness and sleep habits. For objective evaluation was used actigraphy. For cognitive assessment was used the test MoCA (Montreal Cognitive Assessment). The results indicate that the group has class earlier had a greater irregularity of the SWC and a worse performance in cognitive testing. There was a difference between the schedules the week and weekend in the subjective variables, bedtime, wake up and sleep duration in both groups. The objective variables, time in bed showed difference between the schedules the week and weekend to the group started class at 08am and the variables bedtime, get up time, actual sleep time, time in bed and wake bouts in the class at 07am. In the cognitive test, there were differences between the groups in overall score and in the areas of executive function and memory recall. Thus, it is suggested that the class starting time may cause irregularity of the SWC and the irregularity may cause mild cognitive impairment. Moreover, cognitive testing MoCA was sensitive to detect differences among students, although the difference between the schedules is small
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In most primates, the mother is primarily responsible for care in early life of the infants, since, as in other mammals, infants depend on their mother to nutritional conditions. However, unlike most of them, in some species, infants are also dependent on other individuals with respect to transportation, supervision, and food sharing. To understand the distribution of care to offspring is essential to understand the social dynamics of the group. Several studies conducted in the natural environment, during the infant have been studied mainly through the careful transport of the infants. Our study approached the different forms of care to infants (transport, supervision and food sharing) and the development of behavioral repertoire throughout all phases of infant and juvenile seeking to better understand how to establish the development and survival of offspring of Callithrix jacchus, in natural environment. The seasonality in the caatinga was striking in this study and the collection had two distinct seasons for each of the sets observed, one dry and one rainy. These environmental changes seem to have influenced the distribution of activities in animal development. Yet the greater availability of resources in the rainy season seems to have been the main factor influencing the pattern of activities. Results will be presented in two manuscripts