Circadian variation with a diurnal bimodal profile on scent-marking behavior in captive common marmosets (callitrhix jacchus)

Scent-marking behavior is associated with different behavioral contexts in callitrichids, including signalizing a territory, location of feeding resources, and social rank. In marmosets and tamarins it is also associated with intersexual communication. Though it appears very important for the daily routine of the individuals, very few researchers have investigated distribution through the 24-h cycle. In a preliminary report, we described a preferential incidence of this behavior 2 h before nocturnal rest in families of common marmosets. We expand the data using 8 family groups (28 subjects), 8 fathers, 6 mothers, 8 nonreproductive adults (4 sons and 4 daughters), and 6 juvenile (3 sons and 3 daughters) offspring that we kept in outdoor cages under natural environmental conditions. We recorded the frequency of anogenital scent marking for each group during the light phase, twice a wk, for 4 consecutive wks, from March 1998 to September 1999. Cosinor test detected 24- and 8-h variations in 89.3% and 85.7% of the subjects, respectively, regardless of sex or reproductive status. The 8-h component is a consequence of the 2 peaks for the behavior, at the beginning and end of the light phase. Daily distribution of scent marking is similar to that others described previously for motor activity in marmosets. The coincident rhythmical patterns for both behaviors seem to be associated with feeding behavior, as described for callitrichids in free-ranging conditions, involving an increase in foraging activities early in the morning and shortly before nocturnal rest

Análise comparativa e teste empírico da validade dos modelos CAPM tradicional e condicional: o caso das ações da Petrobrás

ALVES, Janaína da Silva. Análise comparativa e teste empírico da validade dos modelos CAPM tradicional e condicional: o caso das ações da Petrobrás. Revista Ciências Administrativas, Fotaleza, v. 13, n. 1, p.147-157, ago. 2007.

Estudo da síntese e sinterização de pós compósitos do sistema Ta-Cu

Ta-Cu bulk composites combine high mechanical resistance of the Ta with high electrical and thermal conductivity of the Cu. These are important characteristics to electrical contacts, microwave absorber and heat skinks. However, the low wettability of Ta under Cu liquid and insolubility mutual these elements come hard sintering this composite. High-energy milling (HEM) produces composite powders with high homogeneity and refines the grain size. This work focus to study Ta-20wt%Cu composite powders prepared by mechanical mixture and HEM with two different conditions of milling in a planetary ball mill and then their sintering using hydrogen plasma furnace and a resistive vacuum furnace. After milling, the powders were pressed in a steel dye at a pressure of 200 MPa. The cylindrical samples pressed were sintered by resistive vacuum furnace at 10-4torr with a sintering temperature at 1100ºC / 60 minutes and with heat rate at 10ºC/min and were sintered by plasma furnace with sintering temperatures at 550, 660 and 800ºC without isotherm under hydrogen atmosphere with heat rate at 80ºC/min. The characterizations of the powders produced were analyzed by scanning electron microscopy (SEM), x-ray diffraction (XRD) and laser granulometry. After the sintering the samples were analyzed by SEM, XRD and density and mass loss tests. The results had shown that to high intense milling condition produced composite particles with shorter milling time and amorphization of both phases after 50 hours of milling. The composite particles can produce denser structure than mixed powders, if heated above the Cu melting point. After the Cu to arrive in the melting point, liquid copper leaves the composite particles and fills the pores

Análise da recuperação em reservatório de gás com baixa permeabilidade (TIGHT GAS) através do fraturamento hidráulico

With the increasing of energetic consumption in the worldwile, conventional reservoirs, known by their easy exploration and exploitation, are not being enough to satisfy this demand, what has made necessary exploring unconventional reservoirs. This kind of exploration demands developing more advanced technologies to make possible to exploit those hydrocarbons. Tight gas is an example of this kind of unconventional reservoir. It refers to sandstone fields with low porosity, around 8%, and permeabilities between 0.1 and 0.0001 mD, which accumulates considerable amounts of natural gas. That natural gas can only be extracted by applying hydraulic fracturing, aiming at stimulating the reservoir, by creating a preferential way through the reservoir to the well, changing and making easier the flow of fluids, thus increasing the productivity of those reservoirs. Therefore, the objective of this thesis is analyzing the recovery factor of a reservoir by applying hydraulic fracturing. All the studies were performed through simulations using the IMEX software, by CMG (Computer Modelling Group), in it 2012.10 version

Produção de forragem verde em sistema hidropônico usando esgoto tratado

In the urban areas of the cities a larger problem of destiny of effluents of the treatment stations is verified due to the junction of the sewages in great volumes. This way the hidroponic cultive becomes important, for your intensive characteristic, as alternative of reuse. This work presents as objective the improvement of the relation hidric-nutritious of the hidroponic cultive of green forage (FVH) using treaty sewage. The production of forage was with corn (Zea mays L.), using double hybrid AG1051, in the experimental field of the Federal University of Rio Grande do Norte (UFRN), in the city of Natal-RN-Brazil. The treated effluent essentially domestic had origin of anaerobic reactor, type decant-digester of two cameras in series followed by anaerobic filters drowned. The hidroponic experimental system was composed of 08 stonemasons, with limited contours for masonry of drained ceramic brick, measuring each one 2,5 meters in length for 1,0 meter of width, with inclination of 4% (m/m) in the longitudinal sense, leveled carefully, in way to not to allow preferential roads in the flow. These dimensions, the useful area of Isow was of 2 square meters. The stonemasons of cultive were waterproof (found and lateral) with plastic canvas of 200 micres of thickness, in the white color. Controlled the entrance and exit of the effluente in the stonemasons, with cycles of 12,68 minutes, it being water of 1,18 minutes. The treatments were constituted of: T1 - 24 hours/day under it waters with flow of 2 L/min; T2 - 12 hours/day under waters with flow of 4 L/min; T3 - 12 hours/day under waters with flow of 2 L/min; and T4 - 16 hours/day under waters with flow of 3 L/min. There were evaluations of the evapotranspirometric demand, of hidroponic system affluent and effluent seeking to characterize and to monitor physical-chemical parameters as: pH, temperature, Electric Conductivity and Fecal Coliforms. This last one was analyzed to the 11 days after isow (DAS) and to the 14 DAS. The others were analyzed daily. I sow it was accomplished in the dates of February 21, 2007, first experiment, and April 10, 2007, second experiment. The density of Isow was of 2 kg of seeds, germinated before 48 hours, for square meter of stonemason. The statistic delineament was it casual entirely with two repetitions, in two experiments. It was applied Tukey test of average to five percent of probability. The cultivation cycle was of 14 DAS with evapotranspirometric demand maximum, reached by T1, of 67,44 mm/day. The analyzed parameters, as mass of green matter - Kg, productivity-Kg/m2 and reason of production of seed FVH/Kg used in Isow, the best result was presented by T1, obtaining value of up to 19,01 Kg/m2 of cultive. Without significant difference, the T4 presented greats values with 16 hours under cycle of water. The Treatments 2 and 3 with 12 hours under cycle of water, they obtained inferior results to the other Treatments. As treatment system, came efficient in the reduction of the salinity. T1 obtained reduction medium maxim of 62,5%, to the 7 DAS, in the amount of salts that enter in the system in they are absorbed in the cultivation. The cultivation FVH acted reducing the microbiologic load. Significant percentile of reduction they were reached, with up to 90,23% of reduction of Units of Colonies (UFC), constituting, like this, the Hidroponic System as good alternative of treatment of effluents of Reactors of high Efficiency

Variação, mudança e ensino: o caso dos pronomes possessivos da gente e nosso(a)(s) em uma abordagem sociofuncionalista

In this work, we analyze the variation and change phenomenon involving the possessive pronouns da gente and nosso(a)(s) in the light of the theoretical referentials of the North-american linguistic functionalism and of the variationist sociolinguistics. At first we present the phenomenon itself, highlighting the fact that few studies have considered it as an object, gap which we will try to fill in with our contribution. In the following chapter, we emphasize concepts and principles of the functionalism and the sociolinguistics that are used as our background for the data analysis. In the third chapter, we present what the normative grammars inform about our object of study, besides synthesizing some works on variation and change involving the personal pronouns nós and a gente. In the following chapter, we analyze the data. We used data from the Discurso & Gramática a língua falada e escrita na cidade do Natal (FURTADO DA CUNHA, 1998) corpus. In this chapter we present the results for the groups of social and linguistic factors which we can control. Grounded on these results, we specify the preferential contexts for employing the pronouns da gente and nosso(a)(s) and we observe that the social motivations, the valorization credited to the forms and the identity marks underly the restrictions exercised in their use by social factor groups, besides obtaining signs of ongoing changes in apparent time (from the age factor groups) and possible use specializations of each form, what helped us verify the course of the grammaticalization process of the referred pronouns in the community of Natal. In the sixth chapter, we make some considerations on the teaching of grammar and propose activities which can be carried on in the classroom involving the possessive pronouns da gente and nosso(a)(s) considering the variation and change issue

Conexão entre as redes complexas e estatística de Kaniadakis e busca eficiente das propriedades críticas do processo epidêmico difusivo 1D

In this work we study a connection between a non-Gaussian statistics, the Kaniadakis statistics, and Complex Networks. We show that the degree distribution P(k)of a scale free-network, can be calculated using a maximization of information entropy in the context of non-gaussian statistics. As an example, a numerical analysis based on the preferential attachment growth model is discussed, as well as a numerical behavior of the Kaniadakis and Tsallis degree distribution is compared. We also analyze the diffusive epidemic process (DEP) on a regular lattice one-dimensional. The model is composed of A (healthy) and B (sick) species that independently diffusive on lattice with diffusion rates DA and DB for which the probabilistic dynamical rule A + B → 2B and B → A. This model belongs to the category of non-equilibrium systems with an absorbing state and a phase transition between active an inactive states. We investigate the critical behavior of the DEP using an auto-adaptive algorithm to find critical points: the method of automatic searching for critical points (MASCP). We compare our results with the literature and we find that the MASCP successfully finds the critical exponents 1/ѵ and 1/zѵ in all the cases DA =DB, DA DB. The simulations show that the DEP has the same critical exponents as are expected from field-theoretical arguments. Moreover, we find that, contrary to a renormalization group prediction, the system does not show a discontinuous phase transition in the regime o DA >DB.

Estudo de sistemas complexos com interações de longo alcance : percolação, redes e tráfego

In this thesis we investigate physical problems which present a high degree of complexity using tools and models of Statistical Mechanics. We give a special attention to systems with long-range interactions, such as one-dimensional long-range bondpercolation, complex networks without metric and vehicular traffic. The flux in linear chain (percolation) with bond between first neighbor only happens if pc = 1, but when we consider long-range interactions , the situation is completely different, i.e., the transitions between the percolating phase and non-percolating phase happens for pc < 1. This kind of transition happens even when the system is diluted ( dilution of sites ). Some of these effects are investigated in this work, for example, the extensivity of the system, the relation between critical properties and the dilution, etc. In particular we show that the dilution does not change the universality of the system. In another work, we analyze the implications of using a power law quality distribution for vertices in the growth dynamics of a network studied by Bianconi and Barabási. It incorporates in the preferential attachment the different ability (fitness) of the nodes to compete for links. Finally, we study the vehicular traffic on road networks when it is submitted to an increasing flux of cars. In this way, we develop two models which enable the analysis of the total flux on each road as well as the flux leaving the system and the behavior of the total number of congested roads

Análises estatísticas em redes complexas: propriedades topológicas, críticas e dinâmicas

In this thesis, we address two issues of broad conceptual and practical relevance in the study of complex networks. The first is associated with the topological characterization of networks while the second relates to dynamical processes that occur on top of them. Regarding the first line of study, we initially designed a model for networks growth where preferential attachment includes: (i) connectivity and (ii) homophily (links between sites with similar characteristics are more likely). From this, we observe that the competition between these two aspects leads to a heterogeneous pattern of connections with the topological properties of the network showing quite interesting results. In particular, we emphasize that there is a region where the characteristics of sites play an important role not only for the rate at which they get links, but also for the number of connections which occur between sites with similar and dissimilar characteristics. Finally, we investigate the spread of epidemics on the network topology developed, whereas its dissemination follows the rules of the contact process. Using Monte Carlo simulations, we show that the competition between states (infected/healthy) sites, induces a transition between an active phase (presence of sick) and an inactive (no sick). In this context, we estimate the critical point of the transition phase through the cumulant Binder and ratio between moments of the order parameter. Then, using finite size scaling analysis, we determine the critical exponents associated with this transition

Contribuições ao estudo das redes complexas: modelo de qualidade

In this work we analyse the implications of using a power law distribution of vertice's quality in the growth dynamics of a network studied by Bianconi anel Barabási. In particular, we start studying the random networks which characterize or are related to some real situations, for instance the tide movement. In this context of complex networks, we investigate several real networks, as well as we define some important concepts in the network studies. Furthermore, we present the first scale-free network model, which was proposed by Barabási et al., and a modified model studied by Bianconi and Barabási, where now the preferential attachment incorporates the different ability (fitness) of the nodes to compete for links. At the end, our results, discussions and conclusions are presented

Dinâmica populacional e alimentar de Stegastes fuscus, (Osteichthyes:pomacentridae) em arrecifes da praia de Búzius, no Rio Grande do Norte

The damselfish, Stegastes fuscus Cuvier, 1830 (Osteichthyes: Perciformes: Pomacentridae), is abundant in the coastal reefs of Búzios Beach, Rio Grande do Norte, Brazil and they play an important role in the reef community ecology. The present study investigated the feeding strategy of this species considering the food habits and morfo-histology of the digestive tract. Influence of the environmental correlates such as temperature, rainfall and luminosity in the tidal rock pools were studied. The fish were captured on a monthly basis from September 2004 to August 2005, during which period 842 individuals of S. fuscus were captured, 125 males, 437 females and 280 individuals without sex identification. The sex ratio observed was 1 M : 3,5 F. The total body length of males varied from 3.6 to 11.3 cm, with a mean of 7.77 cm; that of females varied from 2.9 to 11.4 cm, with a mean of 7.85 cm, and that of sex grouped individuals varied from 2.9 to 11.4 cm, with a mean of 7.83. However, there was no difference between males and females in total body length. This species presented a positive alometric growth and the equations obtained for the relation between body mass and total body length were: Wt =0,0174Lt 3,1123 for males; Wt =0,0137Lt 3,2294 for females and Wt = 0,0148Lt 3.1928 for sex grouped individuals. The relation between total body length and standard length was L t = 1 ,3223Ls + 0,1527 for sex grouped individual s. February to August was associated to a long period of gonadal resting. The fish spawned during January and in September -October. The frequency of fish with empty stomachs occurred during August to December, whereas frequency of fish with food contents i n stomachs occurred during January to July. This species is considered as a preferential herbivore based on the volume of macroalgae in its diet composition. The morfo -histological aspects of S. fuscus confirm herbivory. Among the environmental factors con sidered only rainfall showed a correlation with the feeding habits of this species

A influência do status social no forrageio de itens camuflados e avermelhados em sagüis (Callithrix jacchus) cativos

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

Doenças respiratórias associadas à atividade de mineração no município de Parelhas, região do seridó norte-riograndense

This work aims to characterize the workers in mineral activities exposed to lung injuries in Parelhas Municipality, Rio Grande do Norte State, seeking to relate respiratory diseases to the mining activity. The studied area (Parelhas City), with about 19,700 inhabitants, is located in the Serido region, approximately 232 km far from Natal City. The number of people involved in informal mining activity (garimpo) in the Seridó region reaches about 5,000. These workers generally do not use any kind of individual protection equipments and develop, at early ages of greater productivity, severe forms of diseases, which end up disabling them to professional activities, family and social life. Deceases by respiratory problems (e.g. silicosis) have been reported in very young adults. A descriptive observational study was conducted based on information from the records found in Dr. José Augusto Dantas Hospital, between the years 1996- 2006. The occupational and socio-economic features of the population, which was selected by using the hospital records, were achieved through individually answered forms. The purpose was to link the occupational activities with the respiratory diseases. The next stage of the research was an observational case-control study, in the 1:1 proportion. The achieved data allowed confirming the central hypothesis of the research, which states that the pneumoconiosis cases are due to the mineral-based activities in the studied area. The final step of the investigation tried to assess the knowledge of relatives of students in public and private elementary and high schools from Parelhas City, regarding silicosis. About 15.4% of urban schools were analyzed through application of a structured questionnaire. The results show distinct socio-economic levels and a difference in the perception of the relatives of students in public and private schools, concerning silicosis. It was possible to identify the characteristics of the population economically involved with mineral-based activities and to define the group that deserves preferential attention in preventive actions. The work indicates some environmental problems caused by inadequate mining operations in the region

Dinâmica Costeira dos Campos petrolíferos Macau/Serra, litoral setentrional do Estado do Rio Grande do Norte

This thesis describes the general behavior of the northern shore of the State of Rio Grande do Norte relating beach profile morphology with hydrodynamic and sedimentological parameters. The Macau and Serra Oil Field are inserted on this area and are under accelerated coastal erosion. At these oil fields are installed oil wells from PETROBRAS, nowadays located directly in the shoreline, under constant attacks of coastal processes (e.g. waves, tides and currents), which promote an intense morphodynamic variability of this sandy coast. The area was monitored for 24 months in three different stations (P01, P02 and P03). The methodology applied involved current techniques of beach profiles, hydrodynamical processes, remote sensing and geophysics. A synthesis of results obtained through the use of different time scales (monthly, lunar cycle, seasonal, annual) from a coastal dynamics study is presented. The average wind direction corresponded to 77ºAz (NE). The steepness of the berm and of the shoreface, as well as coastal current direction, do not present major changes, with an average of 36º for the steepness of the berm, 15º for the shoreface and 15º for the coastal current direction. This data set allows us to infer that the months of larger coastal erosion were November/2000 and April/2001, because of the largest wave parameter during this time. The months of worse coastal erosion in this area are related with the increasing wavy energy. This in turn, seems to be related to seasonal climatic variations, with the wave energy and tide currents speed increasing during months of minor precipitations (June to January). The months of worse coastal erosion were September and November, when the largest wave parameters and speed currents are measured in the area. Since these months are included on the period of minor precipitations, we related the coastal erosion to seasonal climatic variations. The results obtained during these 24 months of monitoring confirms a situation of accentuated erosion, mainly in Profile 03 (Barra do Corta-Cachorro), where the wave height, period, and coastal current speed are always larger than the values found in Profile 02 (Macau5). Probably these values are more expressive in Profile 03, because it does not present any natural structure of protection against the wave impacts, as the barrier island located at Ponta do Tubarão, or the sand banks in front of Macau5. The transport of the sediments occurs from East to West, and the sand accumulation is more pronounced on Profile 03 intertidal zone, where there are embrionary dunes in dryer months. The tidal currents speed, on the other hand, is more accentuated in the Macau5 area (Profile 02). At Ponta do Tubarão, the tidal currents presented a preferential direction for NE, at times of flood, currents and for NW, at times of ebb current; at Barra do Corta-Cachorro the direction of the currents were predominantly for NW, independent of the tide phase, coinciding with the preferential direction of the longshore current. This currents inversion at Ponta do Tubarão is attributed to the presence of the Ponta do Tubarão island barrier and by the communication channel of the lagoon with the sea. The tide currents are better observed in protected areas, as in the Ponta do Tubarão, when they present inversion in their direction accordingly to the flood and ebb tide. In open areas, as in Barra do Corta-Cachorro, the tide currents are overprinted by the longshore currents. Sediment analysis does not show important modifications in grain size related to seasonality (dry- and rainy seasons). On the foreshore and backshore zones, the sediments vary from fine to medium sand, while in the shoreface they very from fine to very sands. The grains are mostly spheres, varying from sub rounded to sub angled. Quartz is the main component alongside Feldspat and heavy minerals as accessory components. Biogenic content is also present and mainly represented by mollusks fragments. The calculated sediment transport show values around 100 m3/day. The morphodynamic studies indicated that this is a reflexive area from October to April, and intermediate from May to September. The Relative Tide Range-RTR for this area is 4 < RTR < 15, and so classified in the mixed wave-tide group. Having this exposed we can affirm that the more active natural factors in this area are the currents, followed by the tides and the winds. The anthropic factors are exclusively local and punctual (Macau and Serra Oil Field). Taking in account the economic importance of the area, as well as the intensity of coastal processes acting on this shore, it is important a continuity of the monthly environmental monitoring looking for variations on longer-period cycles. These data have been stored on the geo-referenced database of the projects MARPETRO and PETRORISCO (REDE 05), aiming to model the coastal and sea environment, susceptible to oil spills and their derivatives

Dinâmica e estrutura de redes complexas no modelo de afinidade

In this work we elaborate and discuss a Complex Network model which presents connectivity scale free probability distribution (power-law degree distribution). In order to do that, we modify the rule of the preferential attachment of the Bianconi-Barabasi model, including a factor which represents the similarity of the sites. The term that corresponds to this similarity is called the affinity, and is obtained by the modulus of the difference between the fitness (or quality) of the sites. This variation in the preferential attachment generates very interesting results, by instance the time evolution of the connectivity, which follows a power-law distribution ki / ( t t0 )fi, where fi indicates the rate to the site gain connections. Certainly this depends on the affinity with other sites. Besides, we will show by numerical simulations results for the average path length and for the clustering coefficient