14 resultados para display behavior
em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"
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The Cock-tailed Tyrant (Alectrurus tricolor, Vielliot 1816) is reported here for the first time in the Brazilian Pantanal. The species was seen twice (August and September 2005) in the northern portion of Fazenda Rio Negro, in the region of Nhecolândia. Sexual displays were observed, suggesting that reproduction is occuring in this area.
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In this study, the reproductive behavior exhibited by Arenaeus cribrarius in captivity was described, and the duration of each behavioral stage was measured. Swimming crabs were trawled in Ubatuba, northern littoral of São Paulo State, Brazil, and maintained in aquaria. Water conditions and food items were provided according to this species' natural requirements in the wild. In the presence of premolt females, intermolt males exhibited a courtship display that became intensified when the potential mate was visually perceived. After mate selection, the male carried the female under itself (precopulatory position) for 29.8 +/- 5.1 d until the female molted. Afterwards, the male manipulated the recently molted female, and inverted her position under itself as to penetrate her with his first pair of pleopods (copulation), a process that took 17.1 +/- 4.6 h. After copulation the male continued to carry his soft-shelled mate for 29.7 +/- 5.8 d (postcopulatory position). The time elapsed between copulation and spawning was 57.8 +/- 3.8 d and the time interval between successive spawns 33.8 +/- 7.1 d. Total embryonic development took 13.5 +/- 2.1 d in temperature conditions of 25.0 +/- 2.0 degrees C. During the last 4.7 +/- 1.4 d embryos' eyes were already visible. The reproductive behavior pattern in A. cribrarius is very similar to those previously described in other portunids.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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O comportamento reprodutivo e a ocorrência sazonal de Psecas viridipurpureus foram estudados na Estação Ecológica do Noroeste Paulista, uma pequena área de conservação na região noroeste do Estado de São Paulo, Brasil (49º22'50W e 20º48'36S). P. viridipurpureus ocorreu em gravatás, uma bromeliácea (Bromelia balansae, Bromeliaceae) que não acumula água de chuva. Durante a exibição de corte, o casal ocupou a região mediana das folhas de gravatás, com o macho sempre localizado em uma posição superior à da fêmea. Os machos de P. viridipurpureus apresentaram um comportamento de corte complexo, que incluiu cinco padrões motores. O comportamento de corte e a cópula ocorreram preponderantemente durante a estação chuvosa e o recrutamento de jovens entre dezembro e julho. O abrigo de P. viridipurpureus difere do padrão de Salticidae, pois as ootecas são recobertas por uma cobertura de seda plana e não são incluídas em casulos.
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Cellulose acetate (CA) is one of the most important cellulose derivatives and its main applications are its use in membranes, films, fibers, plastics and filters. CAs are produced from cellulose sources such as: cotton, sugar cane bagasse, wood and others. One promissory source of cellulose is bacterial cellulose (BC). In this work, CA was produced from the homogeneous acetylation reaction of bacterial cellulose. Degree of substitution (DS) values can be controlled by the acetylation time. The characterization of CA samples showed the formation of a heterogeneous structure for CA samples submitted to a short acetylation time. A more homogeneous structure was produced for samples prepared with a long acetylation time. This fact changes the thermal behavior of the CA samples. Thermal characterization revealed that samples submitted to longer acetylation times display higher crystallinity and thermal stability than samples submitted to a short acetylation time. The observation of these characteristics is important for the production of cellulose acetate from this alternative source. (C) 2008 Elsevier B.V. All rights reserved.
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A series of N-isopropylacrylamide (NIPAM)-acrylic acid-ethyl methacrylate terpolymers with varied monomer compositions was prepared by radical polymerization. The solution behavior of these polymers was studied in dilute aqueous solution using spectrophotometry, fluorescence spectroscopy and high-sensitivity differential scanning calorimetry. The results obtained revealed that the lower critical solution temperatures depend strongly on the copolymer composition, solution pH and ionic strength. At a high pH, the ionization of acrylic acid (AA) units leads to an increase in solution cloud points (T-c). Solutions of polymers containing 10% or less of AA display a constant T-c for pH above 5.5, with 15% there is a continuous increase in T-c with pH and, for higher AA contents, no clouding was observed within the studied temperature range. Fluorescence probe studies were conducted by following the I (1)/I (3) ratio of pyrene vibronic bands and the emission of anilinonaphtalene sulfonic acid, sodium salt (ANS), both approaches revealing the existence of hydrophobic domains for polymers with higher ethyl methacrylate content at temperatures lower than T-c, suggesting some extent of aggregation and/or a coil-to-globule transition. Scanning calorimetry measurements showed an endothermic transition at temperatures agreeing with the previously detected cloud points. Moreover, the transition curves became broader and with a smaller transition enthalpy, as both the AA content and the solution pH were increased. These broader transitions were interpreted to be the result of a wider molecular distribution upon polymer ionization, hence, displaying varied solution properties. The decrease in transition enthalpy was rationalized as a consequence of reminiscent hydration of NIPAM units, even after phase separation, owing to the presence of electric charges along the polymer chain.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Rheology has the purpose to study the flux and deformation of materials when submitted to some tension or outer mechanical solicitation. In practice, the effective scientific field broached by rheology is restricted only to the study of homogeneous fluids behavior, in which are included eminent liquids, particles suspensions, and emulsions. The viscosity (η) and the yield stress (τ 0) are the two basic values that define the fluids' behavior. The first one is the proportionality constant that relates the shear rate (γ) with the shear stress (τ) applied, while the second indicates the minimal tension for the flowage beginning. The fluids that obey the Newton's relation - Newtonians fluids - display the constant viscosity and the null yield stress. It's the case of diluted suspensions and grate amount of the pure liquids (water, acetone, alcohol, etc.) in which the viscosity is an intrinsic characteristic that depends on temperature and, in a less significant way, pressure. The suspension, titled Cement Paste, is defined as being a mixture of water and cement with, or without, a superplasticizer additive. The cement paste has a non-Newtonian fluid behavior (pseudoplastic), showing a viscosity that varies in accord to the applied shear stress and significant deformations are obtained from a delimited yield stress. In some cases, systems can also manifest the influence of chemical additives used to modify the interactions fluid/particles, besides the introduced modifications by the presence of incorporated air. To the cement paste the rheometric rehearsals were made using the rheometer R/S Brookfield that controls shear stress and shear rate in accord to the rheological model of Herschel-Bulkley that seems to better adapt to this kind of suspension's behavior. This paper shows the results of rheometrical rehearsals on the cement paste that were produced with cements HOLCIM MC-20 RS and CPV-ARI RS with the addition of superplasticizer additives based of napthaline and polycarboxilate, with and without a constant agitation of the mixture. The obtainment of dosages of superplasticizer additives, as well as the water/cement ratio, at the cement at the fluidify rate determination, was done in a total of 12 different mixtures. It's observed that the rheological parameters seem to vary according to the cement type, the superplasticizer type, and the methodology applied at the fluidity rate determination.
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The aim of this paper is to verify the correlation between environmental indicators and behaviors expressed by laying hens kept in cages. The birds react to a severe environment through their behaviors, end the behaviors can be monitored to identify the birds' welfare conditions. The behaviors birds display ere the result of stress caused by the combination of environmental temperature, relative humidity, radiant heat, and air speed (environmental temperature being the most important). In order to check the influence of the environment, an experiment was carried out on a commercial poultry farm, located in the city of Bastos. The study was initiated in March 2007, during four non-consecutive weeks. The birds' behaviors were recorded using video, by cameras installed in the cages. The birds behaviors were identified and noted for the frequency of occurrence for each bird, and the average duration of each behavior (in seconds), using video samples of 15 minutes recorded from 1 PM to 4 PM. The environmental variables collected were: air temperature, concentration of ammonia, relative air humidity, velocity of the air, noise, roof temperature, and light intensity. The observed behaviors were: opening wings, stretching, threatening, ruffling feathers, drinking water, aggressive pecking, eating, running, lying down, stretching head out of the cage, preening, mounting and prostrating. Principal Components Analysis was used to determine associations between the behavior variables and environmental variables described above. In this experiment, there were no significant correlations between behavioral variables and environmental variables.
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This study reviews published data on the behavior and natural history of Chartergellus and presents the first observations on social interactions in this genus of tropical swarm-founding wasps. Observations of Chartergellus golfitensis in Costa Rica and C. punctatior in Colombia showed that queens perform a post-oviposition egg-guarding vigil, and a bending display like that characteristic of epiponine social wasps that lack consistent morphological differences between workers and queens and have caste determination in the adult stage. Young, old, and queen (egg-laying) females of C. golfitensis showed small differences that indicate color changes with age, and structural differences that could be due to seasonal or colony-cycle changes in developmental conditions, but do not rule out the possibility of pre-adult caste determination, a phenomenon that needs to be carefully distinguished from pre-adult caste bias. Sexual dimorphism and the behavior of males at the nest in C. golfitensis is described, as well as the aggressive and avoidance behavior of females toward males. Nest structure in both species is as described previously for Chartergellus species, but some anomalies and their possible evolutionary significance are discussed. Cell initiation by an egg-laying queen, a behavior never seen by workers, and by a young female with slightly developed ovaries, may be vestiges of ancestral solitary reproductive traits where developed ovaries are associated with cell construction. © 2010 Dipartimento di Biologia Evoluzionistica dell'Università, Firenze, Italia.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)