985 resultados para Shelf life extension


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The biological species (biospecies) concept applies only to sexually reproducing species, which means that until sexual reproduction evolved, there were no biospecies. On the universal tree of life, biospecies concepts therefore apply only to a relatively small number of clades, notably plants and animals. I argue that it is useful to treat the various ways of being a species (species modes) as traits of clades. By extension from biospecies to the other concepts intended to capture the natural realities of what keeps taxa distinct, we can treat other modes as traits also, and so come to understand that the plurality of species concepts reflects the biological realities of monophyletic groups. We should expect that specialists in different organisms will tend to favour those concepts that best represent the intrinsic mechanisms that keep taxa distinct in their clades. I will address the question whether modes of reproduction such as asexual and sexual reproduction are natural classes, given that they are paraphyletic in most clades.

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We have previously shown that exposing rats to a relatively high dose of ethanol during early postnatal life can result in an alteration in spatial learning ability. The hippocampal formation is known to be involved in the control of this ability. The purpose of the present study was to determine whether exposure of rats to ethanol during early postnatal life had either immediate or delayed effects on the numbers of pyramidal cells in the CA1-CA3 subregion of the hippocampus. Wistar rats were exposed to a relatively high daily dose of ethanol at postnatal day 10-15 by placing them for 3 h/day in a chamber containing ethanol vapor. Groups of ethanol-treated (ET), separation control (SC), and mother-reared control (MRC) rats were anesthetized and killed at 16 and 30 days of age by perfusion with phosphate-buffered 2.5% glutaraldehyde. The Cavalieri principle was used to determine the volumes of the CA1 and CA2+CA3 regions. The physical disector method was used to estimate the numerical density of neurons in each of the subdivisions. The total number of pyramidal cells was calculated by multiplying the appropriate estimates of the numerical density by the volume. There were significant age-related reductions in the total numbers of pyramidal cells at 16-30 days of age irrespective of the groups examined. Ethanol treated rats were found to have slightly but significantly fewer pyramidal cell neurons than either the MRC or SC groups. These observations indicate that pyramidal cells in the hippocampus may be vulnerable to a relatively high dose of ethanol exposure during this short period of early postnatal life. (C) 2003 Wiley-Liss, Inc.

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In this paper, we investigate the effects of societal values and life stage on subordinate influence ethics. Based on the evolving crossvergence theory of macro-level predictors of values evolution, we demonstrate the applicability of crossvergence theory in the micro-level context. Furthermore, our study provides the first empirical multi-level analysis of influence ethics utilizing a multi pie-country sample. Thus, we illustrate how the breath of crossvergence can be expanded to provide a multi-level theoretical foundation of values and behavior evolution across cultures. Specifically, we integrate micro-level life stage theory and macro-level societal culture theory to concurrently assess the contributions of each theory in explaining subordinate influence ethics across the diverse societies of Brazil. China, Germany and the U.S. Consistent with previous research, we found significant societal differences in influence ethics. However, we also found that life stage theory played a significant role in understanding influence ethics. Thus, our findings expand the crossvergence perspective on societal change, indicating that key micro-level predictors (e.g., life stage) should be included in cross-cultural research. (C) 2009 Elsevier Inc. All rights reserved.

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Extension of overthickened continental crust is commonly characterized by an early core complex stage of extension followed by a later stage of crustal-scale rigid block faulting. These two stages are clearly recognized during the extensional destruction of the Alpine orogen in northeast Corsica, where rigid block faulting overprinting core complex formation eventually led to crustal separation and the formation of a new oceanic backarc basin (the Ligurian Sea). Here we investigate the geodynamic evolution of continental extension by using a novel, fully coupled thermomechanical numerical model of the continental crust. We consider that the dynamic evolution is governed by fault weakening, which is generated by the evolution of the natural-state variables (i.e., pressure, deviatoric stress, temperature, and strain rate) and their associated energy fluxes. Our results show the appearance of a detachment layer that controls the initial separation of the brittle crust on characteristic listric faults, and a core complex formation that is exhuming strongly deformed rocks of the detachment zone and relatively undeformed crustal cores. This process is followed by a transitional period, characterized by an apparent tectonic quiescence, in which deformation is not localized and energy stored in the upper crust is transferred downward and causes self-organized mobilization of the lower crust. Eventually, the entire crust ruptures on major crosscutting faults, shifting the tectonic regime from core complex formation to wholesale rigid block faulting.

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To study the correlation between caries experience in individuals with cerebral palsy (CP) and the quality of life of their primary caregivers. Sixty-five non-institutionalized individuals, presenting CP, aged 2-21 years old, were evaluated for caries experience. Their respective caregivers aged 20-74 years old answered the Short Form 36 (SF-36) health survey and Independence Measure for Children. Fifty-eight non-disabled individuals (ND group), aged 2-21 years old, and their respective caregivers, aged 25-56 years old, were submitted to the same evaluation process as the CP group. Primary caregivers of CP individuals exhibited significantly lower scores than the ND group in all subscales of the SF-36 health survey questionnaire: physical functioning, physical role, bodily pain, general health, vitality, social functioning, emotional role and mental health. The CP group presented significantly higher values for the Decayed, Missed and Filled (DMF-T) index than the ND group and a significant negative correlation was obtained between the SF-36 and DMF-T index. The results suggest that caregivers of CP individuals exhibited worse quality of life than those of the non-disabled. A negative correlation exists between caries experience of CP individuals and their caregivers` quality of life.

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Formation Of The Maritime Labor Force In Brazil: Culture And Daily Life, Tradition And Resistance (1808-1850). Since the 16(th) Century, Brazil has played a major role in the rise of a new economical and social order, in which ships represented a space of struggle and contradictions among rulers, captains and sailors. This article will study the proletarization process that transformed Indians, small farmers, free and slave black people in maritime labor force in Brazil during the first half of 19(th) century.

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Objectives: To evaluate clinical predictors of poor sleep quality and quality of life (QOL) in patients with hypertrophic cardiomyopathy (HCM). Methods: Consecutive stable patients with HCM were evaluated for the risk of obstructive sleep apnea (OSA) by the Berlin Questionnaire, daytime sleepiness by the Epworth Sleepiness Scale, sleep quality by the Pittsburgh Sleep Questionnaire Index and QOL by the Minnesota Living with Heart Failure Questionnaire. Asymptomatic subjects without HCM were used as controls. Results: We studied 84 patients with HCM and 42 controls who were similar with regard to gender (49 vs. 50% males), age [52 (38-62) vs. 47 (33-58) years] and body mass index (27 +/- 4 vs. 27 +/- 5). HCM diagnosis, high risk for OSA and female gender were independently associated with poor sleep quality in the entire population. Among patients with HCM, poor QOL was independently associated with poor sleep quality, New York Heart Association functional class and diuretic therapy. Conclusion: Poor sleep quality is very common in patients with HCM and may have a negative impact on the QOL, which in turn is an important marker of prognosis in patients with cardiomyopathies. Copyright (C) 2010 S. Karger AG, Basel

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The biphasic life cycle, characterised by metamorphosis from a pelagic larva to a benthic adult, is found throughout the Metazoa. So is sexual reproduction via eggs and sperm. Amidst a tangled web of hypotheses on the origin of metazoan biphasy, current weight of opinion lies with a simple, larva-like holopelagic ancestor that independently settled multiple times to incorporate a benthic phase into the life cycle. This school of thought derives from Haeckel's interpretation of the gastrula as the recapitulation of a gastrean ancestor that evolved via selection on a simple, planktonic hollow ball-of-cells to develop the capacity to feed. We suggest that a paradigm shift is required to accomodate accumulating evidence of the genomic and developmental complexity of the metazoan last common ancestor, which was likely to have already possessed a biphasic lifecycle. Here we incorporate recent evidence from basal metazoans, in particular poriferans, to argue that a more parsimonious theory of the origin of biphasy is as a direct consequence of sexual reproduction in an ancestral benthic adult form. The metazoan embryo can itself be considered the precursor to a biphasic life cycle, wherein the embryo represents one phase and the adult another. Embryos in the water column are subject to natural selection for longeveity and dispersal, which sets them on the evolutionary trajectory towards the crown metazoan planktonic larvae. This alternate view considers the conserved use of regulatory genes in disparate metazoans as a reflection of both the complexity of the LCA and the antiquity of the biphasic life cycle. It does not require that extant embryogenesis, including gastrulation, recapitulates evolution.