Perda de calor por evaporação cutânea associada às características morfológicas do pelame de cabras leiteiras criadas em ambiente tropical

A perda de calor por evaporação cutânea e as características morfológicas do pelame (espessura da capa, comprimento médio dos pêlos, número de pêlos por unidade de área e diâmetro médio dos pêlos) foram avaliadas em 254 cabras das raças Saanen, Alpina e mestiças ½ Boer ½ Saanen. Utilizou-se uma cápsula ventilada para medir a evaporação cutânea, determinada em três regiões do corpo (próximo ao pescoço, meio do flanco e quarto traseiro), enquanto as características morfológicas do pelame foram avaliadas a partir de amostras de pêlos, tomadas 18 cm abaixo da coluna vertebral, exceto a espessura da capa, que foi medida in situ. Os resultados indicaram que os animais apresentam pelame pouco denso, formado por pêlos finos e compridos. Animais mestiços (½ Bôer ½ Saanen) apresentaram taxas de evaporação cutânea mais elevadas que os puros das raças Saanen e Alpina.

Variação anual de características morfológicas e da temperatura de superfície do pelame de vacas da raça Holandesa em ambiente semiárido

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Variação de temperatura e umidade e suas influências nas características físicas e mecânicas dos fios de algodão

Cotton is a hydrofilic textile fiber and, for this reason, it changes its properties according to the environment changes. Moisture and Temperature are the two most important factors that lead a cotton Spinning sector and influence its quality. Those two properties can change the entire Spinning process. Understanding this, moisture and temperature must be kept under control when used during the Spinning process, once the environment is hot and dry, the cotton yarns absorb moisture and lose the minimal consistency. According to this information, this paper was developed testing four types of cotton yarns, one kind of cotton from Brazil and the others from Egypt. The yarns were exposed to different temperatures and moisture in five different tests and in each test, six samples that were examined through physical and mechanical tests: resistance, strength, tenacity, yarn´s hairness, yarn´s evenness and yarn´s twisting. All the analysis were accomplished at Laboratório de Mecânica dos Fluídos and at COATS Corrente S.A., where, it was possible to use the equipments whose were fundamental to develop this paper, such as the STATIMAT ME that measures strength, tenacity, Zweigler G566, that measure hairiness in the yarn, a skein machine and a twisting machine. The analysis revealed alterations in the yarn´s characteristics in a direct way, for example, as moisture and temperature were increased, the yarn´s strength, tenacity and hairness were increased as well. Having the results of all analysis, it is possible to say that a relatively low temperature and a high humidity, cotton yarns have the best performance

Detecção de predadores por dicromatas e tricromatas humanos e a sua implicação na evolução da visão de cores em primatas

Among placental mammals, primates are the only ones to present trichromatic color vision. However, the distribution of trichromacy among primates is not homogeneous: Old World primates shows an uniform trichromacy (with all individuals being trichromats) and New World primates exhibit a color vision polymorphism (with dichromatic males and dichromatic or trichromatic females). Visual ecology studies have investigated which selective pressures may have been responsible for the evolution of trichromacy in primates, diverging from the dichromat standard found in other mammals. Cues associated with foraging and the socio-reproductive status were analyzed, indicating a trichromatic advantage for the rapid detection of visually conspicuous objects against a green background. However, dichromats are characterized by an efficient capture of cryptic and camouflaged stimuli. These advantages regarding phenotype may be responsible for the maintenance of the visual polymorphism in New World primates and for the high incidence of color blindness in humans (standing around 8% in Caucasian men). An important factor that has not yet been experimentally taken into account is the predation risk and its effect on the evolution of trichromacy in primates. To answer this question, we prepared and edited pictures of animals with different coats: oncillas (Leopardus spp.), puma (Puma concolor) and ferret (Galictis cuja). The specimens were taxidermized and the photographs were taken in three different vegetation scenarios (dense forest, cerrado and grassland). The images of the predators were manipulated so that they fit into two categories of stimulus size (small or large). After color calibration and photo editing, these were presented to 40 humans (20 dichromats and 20 trichromats) by a computer program, which presented a set of four photos at a time (one picture containing the taxidermized animal amid the background vegetation and three depicting only the background vegetation) and recorded the response latency and success rate of the subjects. The results show a trichromatic advantage in detecting potential predators. The predator detection was influenced by the background, the predator species, the dimension of the stimulus and the observer s visual phenotype. As humans have a high rate of dyschromatopsias, when compared to wild Catarrhini or human tribal populations, it is possible that the increased rate of dichromats is a result of reduced pressure for rapid predator detection. Since our species came to live in more cohesive groups and resistant to attack by predators, with the advent of agriculture and the formation of villages, it is possible that the lower risk of predation has reduced the selection in favor of trichromats

Comportamento Alimentar da Tilápia Vermelha (Oreochromis niloticus x Oreochromis aureus) Arraçoada com Diferentes Aditivos

The objective of this study was to evaluate the attractive capacity and palatability of a commercial extruded diet flavored with the following coats: fish oil (1%); fish oil (1%) + citric acid (.1%); fish oil (1%) + phosphoric acid (.1%); commercial coat (1%) and dende oil (1%), and the control treatment (absence of coat). The red tilapias feeding behavior was evaluated using a complete randomized experimental design, with 72 observations per treatment. Six 750-L aquariums were used; with three fish (100 +/- .50 g) per aquarium. They had access to the diets, through a couple choice (control x test), in a surface round feeder (feedings), disposed on the opposite lateral of the aquariums. The animals were evaluated during fifteen minutes, twice a day. Due to the use of the chemical substances that did not potencialyzed the feeding response of the red tilapia, it was observed that the usual commercial coat and fish oil did not present an effective addictive to stimulate the ingestion of the extruded diet. Only the commercial coat was lightly capable to provoke confrontation during the feeding process.

Response of human pulps following acid conditioning and application of a bonding agent in deep cavities

Objectives. The aim of this in vivo study was to evaluate the human dental pulp response when a one-bottle adhesive system was applied on etched or unetched deep dentine.Methods. Eighteen class V deep cavity preparations were divided in three groups: group 1-total etching + two coats of single bond (SB) + composite resin (Z-100); group 2-enamel etching + two coats of SB + Z-100, group 3-cavity floor lined with a calcium hydroxide liner (Dycal) + acid-etching of enamel and lateral walls + two coats of SB + Z-100. Two teeth were used as intact control group. After 30 days the teeth were extracted and processed through H and E, Masson's trichrome and Brown and Brenn staining techniques.Results. Moderate inflammatory response, disorganization of pulp tissue, as well as, deposition of thin layer of reactionary dentin were observed in group 1 teeth in which the remaining dentin thickness (RDT) was less than 300 mum. These histological findings appear to be related to long resin tags formation and bonding agent diffusion through dentinal tubules. In group 2, slight inflammatory response was observed only in one tooth in which the RDT was 162 mum. In group 3, all the teeth showed normal histological characteristics which were similar to the intact control group. Presence of bacteria was not correlated with the intensity of pulpal response. The patients reported no symptoms during the experiment. Radiographic evaluation showed no periapical pathology for any of the teeth,Significance and conclusions. Acid-etched deep dentin (RDT less than 300 mum) lined with SB causes more intense pulpal response than unetched deep dentin. Based on the results observed in the present study and the conditions in which it was carried out, we recommend the application of a biocompatible liner before etching deep dentin and applying SB. (C) 2002 Academy of Dental Materials. Published by Elsevier B.V. Ltd. All rights reserved.

Imbibition of Swietenia macrophylla (Meliaceae) seeds: the role of stomata

Background and Aims the occurrence of stomata in seed coats is uncommon and there is limited information about their function(s). The aim of this study was to verify the distribution of stomata in seed coats of Swietenia macrophylla and to relate it to the imbibition process and aspects of the structure of the outer integument layers.Methods For the structural and ultrastructural studies, the seeds were processed using the usual techniques and studied under light and scanning electron microscopes. Histochemical tests were employed to identify the cell wall composition in the different seed coat portions. To assess the role of the stomata in the imbibition, non-impervious seeds were compared with partially impervious ones, in which only the embryo, median or hilar regions were left free. Further, the apoplastic pathway marker was employed to confirm the role of the stomata as sites of water passage during imbibition.Key Results A positive relationship was observed between seed coat thickness and stomata density. The stomata were devoid of movement, with a large pore. They occurred in large numbers in the embryo region and extended with lower frequency towards the wing. Imbibition rates were related to stomata density, suggesting that the stomata act as preferential sites for water entry in the S. macrophylla seeds.Conclusions At maturity, the stomata in the seed coat play a significant role in seed imbibition. The data may also infer that these permanently opened stomata have an important role in gas exchange during seed development, aiding embryo respiration.

Multiple pleurograms in Chamaecrista moench (Leguminosae, caesalpinioideae)

According to the literature, the seeds of Chamaecrista lack pleurograms and have pitted testas aligned in vertical lines. Preliminary observations have revealed that these small structures consist of superficial alterations of the testa that are coloured differently to the rest of the seed coat and stand out as pits. However, no anatomical inspection has yet determined the precise composition of these pits. The present work examined the morphology, surface micromorphology, anatomy, and histochemistry of the seed coat of mature seeds of C. desvauxii var. latistipula, C. flexuosa, and C. nictitans var. patellaria in order to elucidate the structural nature of the seed coat pits. For this, seed coats were studied using scanning electron microscopy and light microscopy. Structural modifications were examined in the seed coats of the studied species, and variations were noted in the mucilaginous layer, in the thickness of the palisade layer, and in the presence of larger hypodermic cells. Based on the anatomical features observed, and comparing these with published data on pleurograms in the Caesalpinioideae, it was determined that the structures referred to previously as tegumental pits on Chamaecrista seeds are actually small and numerous pleurograms, reported here for the first time. (c) 2008 The Linnean Society of London.

LENTIL TANNIN-GLOBULIN INTERACTIONAND and IN VITRO HYDROLYSIS

As frações protéicas foram isoladas dos cotiledones e os taninos isolados e purificados da casca da lentilha. A fração globulina correspondeu a 42,7 % do nitrogenio total da farinha de lentilha representando a fração protéica majoritária. Comparativamente ao metanol e metanol-HCl 1% a mistura acetona:água (7:3) representou o melhor meio extrator para os taninos da casca. A fração globulina isolada, nativa e aquecida (99oC/15 min), e caseína foram hidrolisadas com tripsina e pepsina na ausência de taninos e na presença de relações tanino:proteína de 1:40, 1:20, 1:10, 1:5 e 1:2,5. A hidrólise tríptica e péptica das proteínas não-aquecidas foram reduzidas com o aumento da relação tanino-proteína. A caseína não aquecida mostrou ser mais susceptível à tripsina que à globulina, o oposto sendo observado com a pepsina. O aquecimento seguido de interação com os taninos e hidrólise teve um efeito mais pronunciado sobre a digestão com tripsina que com pepsina para ambas proteínas.

Environmental and genetic variation of the effective radiative properties of the coat of Holstein cows under tropical conditions

Morphological characteristics, coat effective radiative properties, and the percentage of white colour were measured in the coats of 973 Holstein cows, and estimates of the genetic parameters were obtained for these traits, except morphological characteristics. The results showed that white coats are more dense with long, thin hairs, while the black coats are less dense with short, thick hairs. Effective transmissivity is greater in the less-dense coats with short, thin hairs, independently of coat colour. Effective reflectivity depends more on the variation in the radiative properties of the coat and skin surface rather than on the morphological characteristics of the coat. Effective absorptivity is greater in black and dense coats with long, thick hairs, than in the white and less-dense coat with short, thin hairs. All heritability estimates were of low magnitude, except for the percentage of white coat colour.

Radiative properties of the skin and haircoat of cattle and other animals

Radiative properties (reflectance rho, transmittance tau, and absorptance alpha) were determined for wavelengths from 300 to 850 nm in the haircoat and the skin of water buffalo, deer (Pantanal deer, Blastocerus dichotomus), and cattle of the Holstein, Simmental, Canchim, Brangus, and Nelore breeds. The results showed that white hairs have higher rho (0.60 to 0.67) than the other coat colors, but the gray coats (mixed white and dark hair) of the Nelore cattle presented higher rho than that of the white coats of the European breeds at wavelengths lower than 600 nm. The light gray colored skin of the Canchim cattle had higher rho (0. 66) than the non-pigmented skin of Holstein (0.53). Red skins presented rho values higher than those of dark gray and black skins. Buffalo skin (dark gray) presented an average rho of 0.23+/-0.02 and alpha of 0.77+/-0.02. The red haircoat of the deer presented rho lower (0.37) than that of cattle of the same color (0.58). However, there was little difference between deer and cattle with respect to reflectance and absorptance of the skin. As for the spectral transmittance of the skin, it was very low and about the same for both species, until 600 nm. In the range 600 to 850 nm, the tau values for cattle rose to 0. 17, while those for deer increased only to 0.12.

Fungus incidence on peanut grains as affected by drying method and Ca nutrition

An experiment was conducted to study the effects of liming and drying method on Ca nutrition, fungus infection and aflatoxin production potential on peanut (Arachis hypogea) grains. Peanut cv. Botutatu was grown in the absence or presence of liming to raise the base saturation of the soil from 20 to 56%. Calcium contents of the soil were increased from 5.5 to 14.6 mmol((c))kg-1 and pH from 4.2 to 4.9. After harvest, plants and pods were dried in (1) shade, (2) field down to 100 g water kg-1 (3) field down to 250 g water kg-1 and transferred to a forced-air oven at 30°C, (4) field down to 360 g water kg-1 and transferred to a forced-air oven at 30°C. Calcium contents were analyzed in the grains, pericarps and seed coats. The incidence of Aspergillus spp., Penicillium spp., Rhizopus spp. and potential aflatoxin production in vitro were evaluated, as well as the seed coat thickness. The seed coat was thicker when peanut was grown in the presence of lime, leading to a decrease in seed infection by Aspergillus spp. and Penicillium spp. When plants were dried in shade, the growth of aflatoxinogenic fungi was independent of liming. However, in plants dried in the field or field + oven, the development of these fungi was decreased and even suppressed when the Ca content of the seed coat was increased from 2.2 to 5.5 g kg-1.

Study of the venom glands in Ectatomma quadridens (Hymenoptera: Formicidae). Evolutionary hypothesis in subfamily ponerinae

The venom glands of worker ants of the species Ectatomma quadridens morphologically resemble an elongated sac or reservoir ending in a narrower portion that has the function of releasing the secretion to the exterior. Two external secretory filaments are individually inserted into the proximal portion of the gland and end inside the convoluted gland. The venom gland of workers of E. quadridens is, therefore, morphologically subdivided into four distinct portions: a) sac-shaped reservoir measuring approximately 1mm in length; b) excretory duct, proximal portion of the reservoir that joins the gland to the sting apparatus; c) convoluted gland, final portion of the external secretory filaments located inside the reservoir; and d) two secretory filaments measuring about 2 mm in length; their free extremities end blindly and are individually inserted into the reservoir wall at the proximal region of the venom gland. The histological data showed that the filaments and the convoluted gland are composed of cubic cells of secretory function. The reservoir consists of a simple cubical epithelium externally surrounded by muscle fibers. A thick cuticle internally coats the epithelium of the reservoir. The application of histochemical tests allowed us to establish that the final secretion of the venom gland of Ectatomma quadridens is of glycoproteic nature. This secretion undergoes several modifications at the secretory filaments, at the convoluted gland, and in the reservoir before reaching the excretory duct, the point at which the secretion is released in its final composition, namely the venom. Based on the differences among various Ponerinae species we propose a hypothesis suggesting a probable evolutionary process that the venom glands of members of this subfamily might have undergone.

Carotid arteries in the dog: Structure and histophysiology

Light microscopy analysis of the mural structure of the common carotid artery, internal carotid artery and external carotid artery in mongrel dog revealed variability in the middle values of vascular diameter and thickness of the intimal plus medial coats and adventitial coat. The vascular diameter did not differ between the internal carotid artery and external carotid artery, but was significantly increased in the common carotid artery from which the other two arteries had origin. The increased thickness of the intimal plus medial coats of the common carotid artery revealed the constant mechanical adjustment of the arterial wall and local shearing stress that occurred among the arterial coats. The adventitial coat of the internal carotid artery was significantly thicker than those of the common carotid and external carotid arteries, with no significant difference noted between the latter arteries. These histomorphometric results were related to the qualitative observations regarding the mural structure of the three arteries analyzed, especially regarding to the increased thickness and structural complexity of the adventitial coat of the internal carotid artery. Perhaps it acted as an external protective sheath of the vascular wall during its long course until the carotid channel. © 2006 Sociedad Chilena de Anatomía.

Quebra de dormência em sementes de Sesbania virgata (Cav.) Pers

Forest species with hard seeds often pose considerable problems to nursery managers because their hard and impermeable seed coats hinder and delay germination. Therefore, this work aimed to determine the most efficient, practical and low cost methodology to overcome dormancy in Sesbania virgata (Cav.) Pers. Seed, a specie with potential for recovery of degraded areas. The seeds were submitted to chemical scarification by immersion in sulfuric acid during a period of 5, 10, 20 and 30 minutes, mechanical scarification and heat treatment. After the scarification the seeds were submitted to germ test in germination chambers at 25oC and photoperiod of 14 h. Treatment with mechanical scarification showed the highest germination percentage (98%), followed by chemical scarification for 30 minutes (57%). The heat treatment in spite of obtaining a higher germination percentage than the controls had abnormal development of seedlings and is not therefore recommended for seeds of S. virgata. From the parameters utilized in this study, we recommend the use of the mechanical scarification to overcome dormancy of S. virgata seeds.