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The major challenge of this paper comprises an attempt to compare the wealth of folk-information based on "traditional knowledge" with the efficacy of a chemo-biological background based on scientific knowledge. Surprisingly, correlations between plant uses (as food and medicine) and evolutionary status according to morphology (as assigned by Sporne indices) and metabolism (as assigned by diversity of phytochemicals) obey strikingly uniform systematic and evolutionary trends. The resulting patterns suggest a dynamic chemical mechanism for the bioactivity in plants regulated by the antagonistic gallate/caffeate pair. This finding is an important step toward the construction of a coherent chemo-biological language by a dynamic holistic quantitative methodology, one of the most potent prospects for understanding the functioning of nature.  相似文献   

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The American mink’s relationship to the weasels in Mustela has been uncertain. Karyological, morphological, and phylogenetic comparisons to Eurasian Mustela support placing the mink outside the genus as Neovison vison. However, genetic comparisons that incorporate other endemic American Mustela suggest the interpretation of N. vison’s position to Mustela has been handicapped by biased geographic sampling. Here, we analyzed mitochondrial cytochrome-b from all weasels endemic to the Americas, including two poorly known South American species (M. felipei, M. africana), weasels native to North America (M. vison, M. frenata, M. nigripes), Mustela migrant to North America (M. erminea, M. nivalis), palearctic Mustela, and other American members of Mustelidae. Bayesian and likelihood inference methods were used to construct a phylogeny of Mustela, and relaxed Bayesian phylogenetic techniques estimated ages of divergence within the genus using priors calibrated by fossil ages. Our analyses show that the American mink and the smaller Mustela endemic to the Americas represent a distinct phylogenetic heritage apart from their Eurasian cousins, and biogeographic barriers like the Bering and Panamanian land bridges have influenced the evolutionary history of Mustela in the Americas.  相似文献   

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Lee  Raymond L. M. 《Dreaming》2010,20(4):288
Why are dreams easily forgotten or difficult to remember? Dream memory is usually attributed to stored fantasies and imaginations in sleep that have distant or no relevance to waking consciousness. Lack of dream recall suggests the modern emphasis on the significance of waking realities at the expense of oneiric experiences. Yet, in the ancient West and many contemporary non-Western societies, dreaming constitutes an unbroken chain of memory to the organization of everyday life. However, reenchantment in the modern context has given new importance to dream consciousness as vital to the development of the creative self. Emphasis on dream practices or dreamwork as leading to various forms of dream control suggests a quest for mastery of inner space. In this regard, training and motivation in dream recall provide an essential tool for advancing the self's well-being. Dreams are not treated as forgotten fantasies but dynamic pathways to new meanings of the self. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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We report a case of mental retardation associated with multiple congenital anomalies suggesting an F.G. syndrome. We discuss problems concerning genetic counselling and the management of future pregnancies. Unfortunately, no concrete strategy, concerning prenatal diagnosis, can be proposed.  相似文献   

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Senile dementia of Alzheimer's type (AD) is commonly characterized as a neurodegenerative disorder, which exhibits gradual changes of consciousness, loss of memory, perception and orientation as well as loss of personality and intellect. AD prevalence increases dramatically with age and is the fourth cause of death in Europe and in the USA. Currently, there are no available biological markers, which gives clinicians no other alternative than to rely upon clinical diagnosis by exclusion. There is no assay of objective ante mortem biochemical phenomena that relate to the pathophysiology of this disease. The pathophysiology of AD is connected with alterations in neurotransmission, plaque formation, cytoskeletal abnormalities and disturbances of calcium homeostasis. The search for a test, which is non-invasive, simple, cheap and user-friendly, should be directed at accessible body fluids. Only abnormalities replicated in large series across different laboratories fulfilling the criteria for a biological marker are likely to be of relevance in diagnosing AD. To date, only the combination of cerebrospinal fluid tau and Abeta42 most closely approximate an ideal biomarker of Alzheimer's disease. A short review on the role of biological markers in AD on the basis of the literature, contemporary knowledge and our own recent findings are presented.  相似文献   

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The conceptual gulf that separates the 'metabolism first' and 'replication first' mechanisms for the emergence of life continues to cloud the origin of life debate. In the present paper we analyze this aspect of the origin of life problem and offer arguments in favor of the 'replication first' school. Utilizing Wicken's two-tier approach to causation we argue that a causal connection between replication and metabolism can only be demonstrated if replication would have preceded metabolism. In conjunction with existing empirical evidence and theoretical reasoning, our analysis concludes that there is no substantive evidence for a 'metabolism first' mechanism for life's emergence, while a coherent case can be made for the 'replication first' group of mechanisms. The analysis reaffirms our conviction that life is an extreme expression of kinetic control, and that the emergence of metabolic pathways can be understood by considering life as a manifestation of 'replicative chemistry'.  相似文献   

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Hartmann  Ernest 《Dreaming》2010,20(3):149
Is a dream a meteorite—a bit of material arriving from a distant place that needs to be carefully analyzed to give us knowledge about that place (outside or inside us)? Is it a strange text which has come to us in a foreign language, that needs to be translated into our own? This “meteorite view” is held by some religious and spiritual persons, by many orthodox psychoanalysts and other therapists, and implicitly by many researchers. They all see the dream as something alien, something totally different from our ordinary mental functioning. This paper presents a great deal of research favoring an alternate view—that the dream is an earth-stone, not an alien stone. It may be impressive and beautiful (gemstone), but it's still an earth-stone. The dream is part of our mental functioning. It is one end of a continuum, running from focused waking thought, through looser thought, fantasy, daydreaming, reverie and dreaming. We review reasons why dreams are often considered “totally different”: they're perceptual, not conceptual; they're bizarre; they are “so real”; they're so easily forgotten; they're involuntary; they occur in REM sleep—a totally different state. We demonstrate that none of these reasons are persuasive. In each sense, there is overlap between dreams and other forms of functioning. The continuum view leads to different kinds of research and a different style of dreamwork. It also helps answer questions the field has long struggled with including: Should we study “a dream” or “dreaming”? Are dreams meaningful or meaningless? (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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If heat generated through activity can substitute for heat required for thermoregulation, then activity in cold environments may be energetically free for endotherms. Although the possibility of activity-thermoregulatory heat substitution has been long recognized, its empirical generality and ecological implications remain unclear. We combine a review of the literature and a model of heat exchange to explore the generality of activity-thermoregulatory heat substitution, to assess the extent to which substitution is likely to vary with body size and ambient temperature, and to examine some potential macroecological implications. A majority of the 51 studies we located showed evidence of activity-thermoregulatory heat substitution (35 of 51 studies), with 28 of 32 species examined characterized by substitution in one or more study. Among studies that did detect substitution, the average magnitude of substitution was 57%, but its occurrence and extent varied taxonomically, allometrically, and with ambient temperature. Modeling of heat production and dissipation suggests that large birds and mammals, engaged in intense activity and exposed to relatively warm conditions, have more scope for substitution than do smaller endotherms engaged in less intense activity and experiencing cooler conditions. However, ambient temperature has to be less than the lower critical temperature (the lower bound of the thermal neutral zone) for activity-thermoregulatory heat substitution to occur and this threshold is lower in large endotherms than in small endotherms. Thus, in nature, substitution is most likely to be observed in intermediate-sized birds and mammals experiencing intermediate ambient temperatures. Activity-thermoregulatory heat substitution may be an important determinant of the activity patterns and metabolic ecology of endotherms. For example, a pattern of widely varying field metabolic rates (FMR) at low latitudes that converges to higher and less variable FMR at high latitudes has been interpreted as suggesting that warm environments at low latitudes allow a greater variety of feasible metabolic niches than do cool, high-latitude environments. However, activity-thermoregulatory heat substitution will generate this pattern of latitudinal FMR variation even if endotherms from cold and warm climates are metabolically and behaviorally identical, because the metabolic rates of resting and active animals are more similar in cold than in warm environments. Activity-thermoregulatory heat substitution is an understudied aspect of endotherm thermal biology that is apt to be a major influence on the physiological, behavioral and ecological responses of free-ranging endotherms to variation in temperature.  相似文献   

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Women's preferences for masculine male partners have been explained in terms of heritable health. The evidence between masculinity and health, however, is controversial and therefore, alternative explanations for masculinity preferences reflecting income inequality and protection from violence have been proposed. This study thus aimed to test the effect of exposure to violence (i.e., experiences of robberies and perceptions of danger) on the individual masculinity preferences of women and men from the capital city of Colombia, Bogota, and surrounding small towns. One hundred and fifty three adult participants (mean age ± S.D. = 31.3 ± 9.4), all heterosexual, were surveyed in reference to indicators related to health (e.g., drinking water access, frequency of illnesses), access to media (e.g., television and internet access), education (e.g., graduating from high school, attending university) and exposure to violence (e.g., frequency of robberies/attacks, feelings of danger from violence). Participants made two alternatives, preference forced-choice for masculinized and feminized versions of both rural Salvadoran and European male faces. We found that men and women exposed to higher levels of violence preferred less masculine male faces, although this effect was only significant for women. Additionally, the effect of violence exposure was more relevant for the Salvadoran stimuli. Violence contributed significantly to explaining masculinity preferences after controlling for participant age, education, access to media, and health-related factors. These preferences may reflect women's strategy to avoid male violence demonstrating that exposure to violence matters in interpersonal attraction.  相似文献   

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What has the past reaction to the COVID-19 pandemic taught us? We have seen that many low and middle-income countries (LMICs) still lack access to vaccines, and it seems little progress has been made in the last few months and year. This article discusses whether the current strategies, most notably, vaccine donations by the international community and the COVID-19 global access facility COVAX, offer meaningful solutions to tackle the problem. At the centre of our analysis, we compare the concepts of “donations” and “charity” with “vaccine equity” and the “empowerment” of poorer countries. We suggest that the achievement of fair global vaccine production requires that our global approach is supportive of the idea of empowerment. We, therefore, need structural reforms, which would most importantly include capacity building, to positively impact this goal and to take the interests of the global poor seriously.  相似文献   

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The rapid evolution of drug resistance remains a major obstacle for HIV therapy. The capacity of the virus for recombination is widely believed to facilitate the evolution of drug resistance. Here, we challenge this intuitive view. We develop a population genetic model of HIV replication that incorporates the processes of mutation, cellular superinfection, and recombination. We show that cellular superinfection increases the abundance of low fitness viruses at the expense of the fittest strains due to the mixing of viral proteins during virion assembly. Moreover, we argue that whether recombination facilitates the evolution of drug resistance depends critically on how resistance mutations interact to determine viral fitness. Contrary to the commonly held belief, we find that, under the most plausible biological assumptions, recombination is expected to slow down the rate of evolution of multi-drug-resistant virus during therapy.  相似文献   

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