990 resultados para 670103 Fish products
Resumo:
A wide range of peptides produced from milk proteins have been demonstrated to produce a physiological response in model systems. These peptides may be released from intact proteins in the gastrointestinal tract by proteolytic digestion, but are also present in fermented products such as cheese and yogurt, as a result of the action of inherent proteases, such as plasmin, and/or bacterial proteases released by the starter culture. This study investigated the presence of peptides, previously reported to have bioactive properties, in commercially available yogurts and cheeses.
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Recruiting coral reef fish larvae from 38 species and 19 families from New Caledonia were examined for parasites. We found 13 parasite species (Platyhelminthes: Monogenea, Cestoda and Trematoda) but no acanthocephalan, crustacean or nematode parasites. Over 23% of individual fish were infected. Didymozoid metacercariae were the most abundant parasites. We conclude that most of the parasites are pelagic species that become 'lost' once the fish larvae have recruited to the reef. Larval coral reef fish probably contribute little to the dispersal of the parasites of the adult fish so that parasite dispersal is more difficult than that of the fish themselves. (C) 2000 Australian Society for Parasitology Inc. Published by Elsevier Science Ltd. All rights reserved.
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Tarpon have high resting or routine hematocrits (Hct) (37.6+/-3.4%) and hemoglobin concentrations (120.6+/-7.3 g 1(-1)) that increased significantly following bouts of angling-induced exercise (51.9+/-3.7% and 142.8+/-13.5 g 1(-1), respectively). Strenuous exercise was accompanied by an approximately tenfold increase in blood lactate and a muscle metabolite profile indicative of a high energy demand teleost. Routine blood values were quickly restored only when this facultative air-breathing fish was given access to atmospheric air. In vitro studies of oxygen transport capacity, a function of carrying capacity and viscosity, revealed that the optimal Hct range corresponded to that observed in fish under routine behaviour. During strenuous exercise however, further increase in viscosity was largely offset by a pronounced reduction in the shear-dependence of blood which conformed closely to an ideal Newtonian fluid. The mechanism for this behaviour of the erythrocytes appears to involve the activation of surface adrenergic receptors because pre-treatment with propranolol abolished the response. High levels of activity in tarpon living in hypoxic habitats are therefore supported by an elevated Hct with adrenergically mediated viscosity reduction, and air-breathing behaviour that enables rapid metabolic recovery. (C) 2002 Elsevier Science Inc. All rights reserved.
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The colors of 51 species of Hawaiian reef fish have been measured using a spectrometer and therefore can be described in objective terms that are not influenced by the human visual experience. In common with other known reef fish populations, the colors of Hawaiian reef fish occupy spectral positions from 300-800nm; yellow or orange with blue, yellow with black, and black with white are the most frequently combined colors; and there is no link between possession of ultraviolet (UV) reflectance and UV visual sensitivity or the potential for UV visual sensitivity. In contrast to other reef systems, blue, yellow, and orange appear more frequently in Hawaiian reef fish. Based on spectral quality of reflections from fish skin, trends in fish colors can be seen that are indicative of both visually driven selective pressures and chemical or physical constraints on the design of colors. UV-reflecting colors can function as semiprivate communication signals. White or yellow with black form highly contrasting patterns that transmit well through clear water. Labroid fishes display uniquely complex colors but lack the ability to see the UV component that is common in their pigments. Step-shaped spectral curves are usually long-wavelength colors such as yellow or red, and colors with a peak-shaped spectral curves are green, blue, violet, and UV.
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Overcommitment of development capacity or development resource deficiencies are important problems in new product development (NPD). Existing approaches to development resource planning have largely neglected the issue of resource magnitude required for NPD. This research aims to fill the void by developing a simple higher-level aggregate model based on an intuitive idea: The number of new product families that a firm can effectively undertake is bound by the complexity of its products or systems and the total amount of resources allocated to NPD. This study examines three manufacturing companies to verify the proposed model. The empirical results confirm the study`s initial hypothesis: The more complex the product family, the smaller the number of product families that are launched per unit of revenue. Several suggestions and implications for managing NPD resources are discussed, such as how this study`s model can establish an upper limit for the capacity to develop and launch new product families.
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The object of this article is to estimate demand elasticities for a basket of staple food important for providing the caloric needs of Brazilian households. These elasticities are useful in the measurement of the impact of structural reforms on poverty. A two-stage demand system was constructed, based on data from Household Expenditure Surveys (POF) produced by IBGE (The Brazilian Bureau of Statistics) in 1987/88 and 1995/96. We have used panel data to estimate the model, and have calculated income, own-price, and cross-price elasticities for eight groups of goods and services and, in the second stage, for 11 sub groups of staple food products. We estimated those elasticities for the whole sample of consumers and for two income groups.
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Consumers worldwide are increasingly concerned with sustainable production and consumption. Recently, a comprehensive study ranked 17 countries in regard to their environmentally friendly behaviour among consumers. Brazil was one of the top countries in the list. Yet, several studies highlight significant differences between consumers` intentions to consume ethically, and their actual purchase behaviour: the so-called `Attitude-Behaviour Gap`. In developing countries, few studies have been conducted on this issue. The objective of this study is therefore to investigate the gap between citizens` sustainability-related attitudes and food purchasing behaviour using empirical data from Brazil. To this end, Brazilian citizens` attitudes towards pig production systems were mapped through conjoint analysis and their coexistence with relevant pork product-related purchasing behaviour of consumers was investigated through cluster analysis. The conjoint experiment was carried Out with empirical data collected from 475 respondents surveyed in the South and Center-West regions of Brazil. The results of the conjoint analysis were used for a subsequent cluster analysis in order to identify clusters of Brazilian citizens with diversified attitudes towards pig production systems, using socio-demographics, attitudes towards sustainability-related themes that are expected to influence the way they evaluate pig production systems, and consumption frequency of various pork products as clusters` background information. Three clusters were identified as `indifferent`, `environmental conscious` and `sustainability-oriented` citizens. Although attitudes towards environment and nature had indeed an influence on citizens` specific attitudes towards pig farming at the cluster level, the relationship between `citizenship` and consumption behaviour was found to be weak. This finding is similar to previous research conducted with European consumers: what people (in their role of citizens) think about pig production systems does not appear to significantly influence their pork consumption choices. Improvements in the integrated management of this chain would better meet consumers` sustainability-related expectations towards pig production systems.
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Loss of connectivity in impounded rivers is among the impacts imposed by dams, and mitigation measures such as fish passages might not accomplish their purpose of reestablishing an efficient bi-directional gene flow in the fish populations affected. As a consequence, fish populations remain fragmented, and a new interpopulational structure may develop, with increased risk of reduced genetic diversity and stochastic extinction. In order to evaluate the effects of the Gavio Peixoto Dam, which was constructed almost a century ago on the Jacar,-Gua double dagger u River in the Upper Parana River basin, Brazil, a comparative morphometric study was undertaken on the populations of the Neotropical migratory characid fish Salminus hilarii living up- and downstream of this dam. Population dynamics, spatial segregation, and habitat use by different age classes were monitored for 2 years. We found that segregation caused by the dam and long periods with no efficient connection by fish passages have led to fragmentation and interpopulational structuring of S. hilarii, as revealed by canonical variable analysis of morphometric features. The fish populations occupying the up- and downstream sections have succeeded in performing short-distance reproductive migrations in the main river and tributaries, have found suitable habitats for completing their life cycle, and have been able to maintain distinct small-sized populations so far.
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A sensitive and precise stir bar sorptive extraction (SBSE) combined with LC (SBSE/LC) analysis is described for simultaneous determination of methyl, ethyl, propyl, and butyl parabens in commercial cosmetic products in agreement with the European Union Cosmetics Directive 76/768/EEC. Important factors in the optimization of SB SE efficiency are discussed, such as time and temperature of extraction, pH, and ionic strength of the sample, matrix effects, and liquid desorption conditions by different modes (magnetic stirring, ultrasonic). The LOQs of the SBSE/LC method ranged from 30 to 200 ng/mg, with linear response over a dynamic range, from the LOQ to 2.5 mu g/mg, with a coefficient of determination higher than 0.993. The interday precision of the SBSE/LC method presented a coefficient of variation lower than 5%. The effectiveness of the proposed method was proven for analysis of commercial cosmetic products such as body creams, antiperspirant creams, and sunscreens.
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Recently, conservationists have debated whether consumers of animal and plant potency products used to treat erectile dysfunction (ED) in traditional Chinese medicine (TCM) might be switching to Viagra, consequently consuming fewer of these animals and plants. To address this question, a survey examined the medical decisions of male consumers of TCM in Hong Kong who were over the age of 50. As predicted, these consumers reported selectively switching to Western medicines to treat ED, but not to treat other health ailments. These findings provide support for the possibility that Viagra may have conservation benefits for certain species.
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In recent years our understanding of the control of ion and urea metabolism in elasmobranch fish has increased with many more species being investigated. This has demonstrated that many species regarded as stenohaline marine are at least, partially euryhaline and may survive in environments less concentrated than full seawater. This presentation will review these recent findings and then compare the osmoregulatory strategies of a partially euryhaline species, Scyliorhinus canicula, with a fully euryhaline migratory species Carcharinus leucas. This will include new data for both species and will generate new models for the control of ion and urea metabolism in elasmobranchs on which to base future research.
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To date very Few families of critical sets for latin squares are known. The only previously known method for constructing critical sets involves taking a critical set which is known to satisfy certain strong initial conditions and using a doubling construction. This construction can be applied to the known critical sets in back circulant latin squares of even order. However, the doubling construction cannot be applied to critical sets in back circulant latin squares of odd order. In this paper a family of critical sets is identified for latin squares which are the product of the latin square of order 2 with a back circulant latin square of odd order. The proof that each element of the critical set is an essential part of the reconstruction process relies on the proof of the existence of a large number of latin interchanges.
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The products formed by a fructan:fructan fructosyltransferase (FFT) activity purified from Lolium rigidum Gaudin were identified after gas chromatography-mass spectrometry of partially methylated alditol acetates, electrospray ionization-mass spectrometry and reversed-phase high-performance liquid chromatography. The FFT activity synthesized oligofructans up to degree of polymerization (DP) 6, but did not synthesize fructans of DP > 6 even when assayed with (1,1,1)-kestopentaose for up to 10 h. The FFT activity when assayed with 1-kestose or 6(G)-kestose synthesized fructan with fructosyl residues almost exclusively linked by beta-2,1-glycosidic linkages. When assayed with 1-kestose, the FFT activity synthesized tetrasaccharides and pentasaccharides with an internal glucosyl residue. The predominant tetrasaccharide was (1&6(G))-kestotetraose and the predominant pentasaccharide was (1&6(G),1)-kestopentaose. By comparison, tetrasaccharides and pentasaccharides extracted from L. rigidum also contained predominantly beta-2,1-glycosidic linked fructans with an internal glucosyl residue. The only exception was that one of the pentasaccharides contained beta-2,1- and beta-2,6-glycosidic linked fructosyl residues. This pentasaccharide was not synthesized by the FFT activity. The role of this FFT activity in formation of oligofructans in L. rigidum is discussed.
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Bothriocephalus acheilognathi was collected from 13 of 38 carp (Cyprinus carpio), 2 of 4 mosquito fish (Gambusia holbrooki), and 2 of 12 western carp gudgeon (Hypseleotris klunzingeri) in waterways of the Australian Capital Territory and New South Wales. This is the first record of this parasite in Australia, and its presence in H. klunzingeri is a new host record. B. acheilognathi presumably arrived in Australia with its introduced fish hosts and has since crossed into native fishes, This cestode may infect other native fish species, a potential that is significant given the high pathogenicity associated with infection in other known hosts.
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The fatty acid composition of 11 species of fish caught off the northeast coast of Australia was determined. No fatty acid profiles have been previously published for fish from this area nor for nine of these species. Although the percentage of polyunsaturated fatty acid (PU FA) was the same as the calculated average for Australian fish (42.3%), the percentage of n-3 fatty acids was lower (24.4 +/- 5.4% vs. 30.7 +/- 10.1%) and the n-6 fatty acids higher (16.5 +/- 4.5% vs. 11.2 +/- 5.9%), P < 0.001 in each case. The major n-3 PUFA were docosahexaenoic (15.6 +/- 6.3%) and eicosapentaenoic acid (4.3 +/- 1.1%) while the major n-6 PUFA were arachidonic (8.3 +/- 3.2%) and n-6 docosatetraenoic acid (3.1 +/- 1.3%). The second-most abundant class of fatty acid was the saturates (31.6 +/- 3.5%) while the monounsaturates accounted for 17.4 +/- 4.3% of the total fatty acids. The monounsaturate with the highest concentration was octadecenoic acid (11.8 +/- 2.6%). There was a positive correlation between the total lipid content and saturated and monounsaturated fatty acids (r = 0.675 and 0.567, respectively) and a negative correlation between the total lipid content and PUFA(r = 0.774).