845 resultados para sensory ecology


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Asphodelus tenuifolius is becoming a more common weed in rain-fed area in Pakistan. Laboratory and greenhouse experiments were conducted to determine the effect of different environmental factors on germination and emergence of A.tenuifolius. Results showed that A.tenuifolius can tolerate a wide range of varying environmental factors. Greatest percentage of germination (80%) was recorded at 15 ºC constant temperature; however, considerable germination occurred at 20 and 25 ºC. Light for 10 h photoperiod stimulate germination of Asphodelus tenuifolius compared with complete darkness. Germination was totally inhibited at osmotic stress higher than -0.8 MPa. There was no significant difference in germination at pH 6 to 8; however, there was a slightly decrease at pH 9, compared with distilled water. Asphodelus tenuifolius was very sensitive to salinity; however, a few seeds of A.tenuifolius were able to germinate even at 150 mM NaCl concentration. Greatest emergence occurred with seed placed at soil surface and emergence decreased with increase in burial depth. No emergence occurred from 4 cm or greater. This information may aid in developing tools and strategies for management.

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Aspects of population dynamics and life history of Paepalanthus polyanthus (Bong.) Kunth, a sand dune monocarpic plant, were evaluated. A five year study was carried out on three permanent plots (5 m x 5 m) in a sand dune slack at Joaquina beach, Santa Catarina State, Brazil. From December 1986 to June 1989, the population decreased due to the death of the post reproductive plants and a low emergence of seedlings. In June 1989, a great recruitment occurred, but no plants survived. The population re-established itself by 1990-1991. The emergence and high survival of seedlings depended on periods of high pluviosity. Nevertheless, the summer flooding and episodes of drought represented key factors in mortality. The birth and mortality rates varied among the areas. It is suggested that these differences are related with depth of the ground water and with vegetation cover at each site. Paepalanthus polyanthus can reproduce in the second year of life, but few plants do this. The chances of survival and reproduction increase with the size of the basal leaf rosette. Although the production of seeds increases with size, the risk of unexpected flooding, for instance, suggest that a great delay in reproduction might not be the most favorable strategy.

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The pollination ecology and breeding systems of Tabebuia aurea (Manso) Benth. & Hook., and T. ochracea (Cham.) Standl. were investigated in an area of cerrado vegetation in the Federal District of Brazil. These species occur sympatrically, flower massively and synchronously for a month, during the dry season (July to September). Both have diurnal anthesis, with similar floral structures, a yellow tubular corolla and produce nectar. Fourteen species of bees visited both Tabebuia species, but, only three Centris species and Bombus morio, were considered potential pollinators, because of their high frequency on the flowers and their efficiency in carrying pollen. Tests on the breeding systems of T. aurea and T. ochracea demonstrated that boths species are self-incompatible, with late-acting self-incompatibility. The proportion of fruit set from cross pollination (T. aurea 17.2% and T. ochracea 12.3%) in both species was low considering the great number of flowers displayed. This suggests a lack of maternal resources for fruit-set. The great amount of seeds per fruit (about 92 in T. aurea and 285 in T. ochracea) may represent an investment of maternal resources allocated on higher quality of fertilized ovules.

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This is a review of the research undertaken since 1971 on the behavior and physiological ecology of sloths. The animals exhibit numerous fascinating features. Sloth hair is extremely specialized for a wet tropical environment and contains symbiotic algae. Activity shows circadian and seasonal variation. Nutrients derived from the food, particularly in Bradypus, only barely match the requirements for energy expenditure. Sloths are hosts to a fascinating array of commensal and parasitic arthropods and are carriers of various arthropod-borne viruses. Sloths are known reservoirs of the flagellate protozoan which causes leishmaniasis in humans, and may also carry trypanosomes and the protozoan Pneumocystis carinii.

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The rate of axonal regeneration, after sciatic nerve lesion in adult C57BL/6J mice, is reduced when compared to other isogenic strains. It was observed that such low regeneration was not due just to a delay, since neuronal death was observed. Two general mechanisms of cell death, apoptosis and necrosis, may be involved. By using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) technique, we demonstrated that a large number of sensory neurons, as well as satellite cells found in the dorsal root ganglia, were intensely labeled, thus indicating that apoptotic mechanisms were involved in the death process. Although almost no labeled neurons or satellite cells were observed one week after transection, a more than ten-fold increase in TUNEL labeling was detected after two weeks. The results obtained with the C57BL/6J strain were compared with those of the A/J strain, which has a much higher peripheral nerve regeneration potential. In A/J mice, almost no labeling of sensory neurons or satellite cells was observed after one or two weeks, indicating the absence of neuronal loss. Our data confirm previous observations that approximately 40% of C57BL/6J sensory neurons die after sciatic nerve transection, and indicate that apoptotic events are involved. Also, our observations reinforce the hypothesis that the low rate of axonal regeneration occurring in C57BL/6J mice may be the result of a mismatch in the timing of the neurons need for neurotrophic substances, and production of the latter by non-neuronal cells in the distal stump.

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This article is an edited transcription of a virtual symposium promoted by the Brazilian Society of Neuroscience and Behavior (SBNeC). Although the dynamics of sensory and motor representations have been one of the most studied features of the central nervous system, the actual mechanisms of brain plasticity that underlie the dynamic nature of sensory and motor maps are not entirely unraveled. Our discussion began with the notion that the processing of sensory information depends on many different cortical areas. Some of them are arranged topographically and others have non-topographic (analytical) properties. Besides a sensory component, every cortical area has an efferent output that can be mapped and can influence motor behavior. Although new behaviors might be related to modifications of the sensory or motor representations in a given cortical area, they can also be the result of the acquired ability to make new associations between specific sensory cues and certain movements, a type of learning known as conditioning motor learning. Many types of learning are directly related to the emotional or cognitive context in which a new behavior is acquired. This has been demonstrated by paradigms in which the receptive field properties of cortical neurons are modified when an animal is engaged in a given discrimination task or when a triggering feature is paired with an aversive stimulus. The role of the cholinergic input from the nucleus basalis to the neocortex was also highlighted as one important component of the circuits responsible for the context-dependent changes that can be induced in cortical maps.

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The goal of the present research was to elucidate the roles and mechanisms by which the sensory nervous system, through the actions of potent vasodilator neuropeptides, regulates cardiovascular function in both the normal state and in the pathophysiology of hypertension. The animal models of acquired hypertension studied were deoxycorticosterone-salt (DOC-salt), subtotal nephrectomy-salt (SN-salt), and Nomega-nitro-L-arginine methyl ester (L-NAME)-induced hypertension during pregnancy in rats. The genetic model was the spontaneously hypertensive rat (SHR). Calcitonin gene-related peptide (CGRP) and substance P (SP) are potent vasodilating neuropeptides. In the acquired models of hypertension, CGRP and SP play compensatory roles to buffer the blood pressure (BP) increase. Their synthesis and release are increased in the DOC-salt model but not in the SN-salt model. This suggests that the mechanism by which both models lower BP in SN-salt rats is by increased vascular sensitivity. CGRP functions in a similar manner in the L-NAME model. In the SHR, synthesis of CGRP and SP is decreased. This could contribute to the BP elevation in this model. The CGRP gene knockout mouse has increased baseline mean arterial pressure. The long-term synthesis and release of CGRP is increased by nerve growth factor, bradykinin, and prostaglandins and is decreased by alpha2-adrenoreceptor agonists and glucocorticoids. In several animal models, sensory nervous system vasoactive peptides play a role in chronic BP elevation. In the acquired models, they play a compensatory role. In the genetic model, their decreased levels may contribute to the elevated BP. The roles of CGRP and SP in human hypertension are yet to be clarified.

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Sensory analysis was used to get an overall flavour description of a reaction mixtures containing 5'-IMP and Cysteine. Ribose/cysteine systems were used as reference systems. Results from triangle and aroma profiling show a clear correlation between the terms used and the volatile analysis described in literature for these model systems. For instance reactions at pH 3.0 and 4.5 for 5'-IMP/cysteine systems, which were described as "meaty" and "boiled meat" by panellists, presented, in the literature, the higher number of "meaty" compounds in volatile analysis (1, 7, 8, 20) .

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ICT contributed to about 0.83 GtCO2 emissions where the 37% comes from the telecoms infrastructures. At the same time, the increasing cost of energy has been hindering the industry in providing more affordable services for the users. One of the sources of these problems is said to be the rigidity of the current network infrastructures which limits innovations in the network. SDN (Software Defined Network) has emerged as one of the prominent solutions with its idea of abstraction, visibility, and programmability in the network. Nevertheless, there are still significant efforts needed to actually utilize it to create a more energy and environmentally friendly network. In this paper, we suggested and developed a platform for developing ecology-related SDN applications. The main approach we take in realizing this goal is by maximizing the abstractions provided by OpenFlow and to expose RESTful interfaces to modules which enable energy saving in the network. While OpenFlow is made to be the standard for SDN protocol, there are still some mechanisms not defined in its specification such as settings related to Quality of Service (QoS). To solve this, we created REST interfaces for setting of QoS in the switches which can maximize network utilization. We also created a module for minimizing the required network resources in delivering packets across the network. This is achieved by utilizing redundant links when it is needed, but disabling them when the load in the network decreases. The usage of multi paths in a network is also evaluated for its benefit in terms of transfer rate improvement and energy savings. Hopefully, the developed framework can be beneficial for developers in creating applications for supporting environmentally friendly network infrastructures.

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The purpose of research was to investigate the bacterial ecology of tilapia (Oreochromis niloticus) fresh fillets and some factors that can influence its microbial quality. Samples of fish cultivation water (n = 20), tilapia tegument and gut (n = 20) and fresh fillets (n = 20) were collected in an experimental tilapia aquaculture located in the city of Lavras, Minas Gerais, Brazil. Staphylococcus spp., Aeromonas spp., Enterococcus spp. and Enterobacteriaceae were quantified using selective plating. For the enumeration of Pseudomonas spp., the most probable number technique (MPN) was utilized. Bacterial colonies (n = 198) were identified by Gram strain and biochemical tests. Aeromonas spp., Pseudomonas spp., Enterococcus spp. and Enterobacteriaceae were found in the cultivation water (water from a fishpond cultivation), tegument, gut, and fresh fillets. Staphylococcus spp. was not isolated in the cultivation water. Salmonella spp. was not detected. The count variable of 10 to 10³ CFU or MPN.(g or mL)-1. Associated to freshwater tilapia fillet processing, there is a large variety of microorganisms related to foodborne illnesses and fish products deterioration.

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The oil obtained from Brazilian roasted coffee by supercritical CO2 extraction shows considerable aromatic properties, mainly composed by five aromatic compounds, 2-methylpyrazine; 2-furfurylalcohol, 2,5-dimethylpyrazine; γ-butyrolactone and 2-furfurylacetate. Sensory analyses were used to verify the influence of a mixture of these important classes of aromatic coffee compounds (pyrazines, furans and lactones) and of the roasted coffee aromatic oil on the coffee aroma and flavour of black instant freeze and spray-dried coffee beverages. In the acceptance evaluation of the aroma, the samples prepared with freeze-dried instant coffee without the mixture of volatile compounds (sample 4) were not significantly different from the freeze-dried instant coffee in which the aromatic coffee oil was added (sample 5) and from the sample prepared with freeze-dried coffee in which the mixture of the five volatile was added (sample 3), coincidentally from the same drying process. Therefore, sample (3) did not differ from samples prepared with spray dried instant coffee without (sample 1) and to which (sample 2) the mixture of volatile was added. Therefore, with respect to this attribute, the addition of this mixture did not interfere in this drink acceptance. Taking into consideration the flavor, samples prepared with freeze-dried instant coffee in which the aromatic coffee oil was added (5) and the samples with (3) and without (4) the mixture of the five volatile was added did not differ significantly, however sample (4) did not differ from samples (1) and (2). Regarding this attribute, the addition of the aromatic oil of roasted coffee or a mixture of volatile in samples of freeze-dried instant coffee had a better acceptance than those dried by spray dryer (1) and (2). Thus, the enrichment of drinks with the aromatic oil of roasted coffee, or even with the mixture of the five components did not influence the consumer acceptance with respect to the aroma, but exerts influence with respect to flavour.

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Despite its high nutritional value, soymilk consumption in Western countries is limited mainly due to undesirable flavors developed during the traditional elaboration process. Brazil nut (Bertholletia excelsa) has pleasant flavor and recognized nutritional value. Thus, the aim of this work was to elaborate a soy and Brazil nut beverage exploring the use of two national products of high nutritional quality. The process for manufacturing a soy and Brazil nut beverage consisted of elaboration, formulation, and homogenization of soymilk and Brazil nut milk. The addition of five levels (10, 20, 30, 40, and 50%) of Brazil nut milk to soy beverages was investigated. Although no significant differences in consumer average preference (p > 0.05) were observed among the beverages, analyzing both the consumer preference frequency distribution of the products and the Internal Preference Mapping (IPM), it was possible to conclude that the beverage with 30% of Brazil nut milk reached the most adequate performance demonstrating the sensory benefits Brazil nuts brought to the product. Regarding proximate composition, it did not present a better performance in terms of nutritional value, except for the oil content. The soy and Brazil nut beverage presented visual stability and no phase separation despite the non-stability shown by Brazil nut beverage itself. When Brazil nut milk was added to soy beverage, the final product became whiter than soy beverage, which is appealing to consumers who normally search for a clearer soymilk. The soy and Brazil nut beverage processing can be considered an alternative to increase the use of Brazil nuts in the Brazilian diet.

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The use of hydrolysed meat in diets contributes to the improvement of protein, vitamin and mineral supply. This work aims at checking the acceptance pattern in meat hydrolysates. Four preparations have been developed with three types of hydrolysates in domestic-like conditions. Acceptance was verified by means of sensory analysis using the nine-point hedonic scale. Sensory tests have been carried out in three sessions (according to the kind of hydrolysates). In the evaluation file, information on age groups has been included. The statistical analysis has been made by ANOVA and Tukey test. The best accepted preparation have been the turkey and chicken hydrolysed balls. Hydrolysates can be used in many different kinds of preparations, but it is necessary to know both the age group it will be used to and its sensory and chemical-physical features to ensure the taste and the original appearance of the final product.

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The objective of this study was to examine sensory differences between conventional rice and iron-fortified Ultra Rice rice (UR) and determine consumer acceptance. Differences between both types of rice were analyzed using the Duo-Trio Test on 37 non-trained judges. The Acceptance Test evaluated general rice appearance, color, aroma and taste by 43 non-trained judges, using a 7-point hedonic scale with extremes ranging from "really disliked" and "really liked." There were no significant differences between the analyzed samples of conventional rice and UR rice using Duo-Trio Test. Mean values from the Acceptance Test for the evaluated attributes (general appearance, color, aroma e taste) were 5.6 and 5.9, corresponding to "liked" and "really liked" according to the hedonic scale, respectively. The iron did not alter the sensory characteristics of the final product, and the iron-fortified rice was well accepted.

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The quality of flat breads depends in part on the textural properties of breads during storage. These properties are largely affected by flour protein quality and quantity. The present study aimed to examine differences between sensory properties, textural and staling of Tandoori breads made from flours of different quality and different quantities of protein. This was implemented by using three flours with 9.4, 11.5 and 13.5% protein contents and different protein qualities shown by Zeleney sedimentation volume 16.25, 22.75 and 23.25 mL respectively. Bread strips were submitted to uniaxial compression between two parallel plates on an Instron Universal Testing machine, and firmness of the breads was determined. Results indicated the differences in the sensory attributes of breads produced by flours of different protein content and quality, demonstrating that high protein high quality flours are not able to sheet and expand under the high temperature - short time conditions employed in Taftoon bread production and are therefore not suitable for this kind of bread. Results showed that flour with 11.5% protein content, produced bread with better sensory characteristics and acceptable storage time.