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1.
Life is a complex phenomenon that not only requires individual self-producing and self-sustaining systems but also a historical-collective organization of those individual systems, which brings about characteristic evolutionary dynamics. On these lines, we propose to define universally living beings as autonomous systems with open-ended evolution capacities, and we claim that all such systems must have a semi-permeable active boundary (membrane), an energy transduction apparatus (set of energy currencies) and, at least, two types of functionally interdependent macromolecular components (catalysts and records). The latter is required to articulate a 'phenotype-genotype' decoupling that leads to a scenario where the global network of autonomous systems allows for an open-ended increase in the complexity of the individual agents. Thus, the basic-individual organization of biological systems depends critically on being instructed by patterns (informational records) whose generation and reliable transmission cannot be explained but take into account the complete historical network of relationships among those systems. We conclude that a proper definition of life should consider both levels, individual and collective: living systems cannot be fully constituted without being part of the evolutionary process of a whole ecosystem. Finally, we also discuss a few practical implications of the definition for different programs of research.  相似文献   

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Kolombet  V. A.  Lesnykh  V. N.  Elistratov  A. V.  Kolombet  E. V.  Fedorov  M. V.  Shnoll  S. E. 《Biophysics》2019,64(2):300-308
Biophysics - The universal period-tripling system has been discovered in various astronomical, geophysical, and biological phenomena in the range of periods from 1.64 billion years to 50 years; we...  相似文献   

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Many theories on origin of life at the end of the XIXth century and the beginning of the XXth, generally use conceptions of life instead of explicit definitions of life. This paper presents ideas on the origin of life as studied by Buffon (1707–1788), Lamarck (1744–1829), Darwin (1809–1882), Huxley (1825–1895), Oparin (1894–1980) and Haldane (1892–1964). We show that their conceptions on the evolution of matter and life reveal their conceptions of life rather than their definitions of life.  相似文献   

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Welfare improvements for nonhuman animals should aim to satisfy the needs of visitors as well as those of the animals. Little research has been conducted, however, and existing work is confined to zoos in developed countries. This article reports the behavioral responses of Chinese visitors to environmental enrichment improvements in a zoo enclosure. Visit, viewing, and stopping behaviors significantly increased at the transformed exhibit, indicating that it provoked greater visitor interest. Furthermore, increased intragroup behaviors suggested that the exhibit probably motivated visitors to interact socially. The positive impact of the exhibit changes supports the enrichment efforts taking place in zoos around the world. The changes also provide encouragement for zoos in developing countries such as China because greater visitor interest provides a strong argument and an incentive for improving welfare standards.  相似文献   

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《Endocrine practice》2011,17(1):122-131
ObjectiveTo present a case of primary menopausal insomnia with hot flashes to introduce recent changes in technology and nomenclature of sleep medicine and to review presentation, diagnosis, and therapies for menopausal insomnia.MethodsClinical findings and results of sleep evaluation in the menopausal study patient are presented with details about polysomnography performed before and after therapy with pregabalin.ResultsA 56.5-year-old female athlete with severe hot flashes and insomnia of 12 years duration was treated with pregabalin, which ameliorated the hot flashes and sweats and improved sleep quality and architecture. Menopause is associated with hormonal and metabolic changes that disrupt sleep. Disruption of sleep can in turn lead to morbidity and metabolic sequelae. Hormonal treatment, although effective, carries risks unacceptable to many patients and physicians. To date, nonhormonal therapies of symptomatic menopause have not been objectively studied for effects on sleep efficiency and architecture. Primary menopausal insomnia is insomnia associated with menopause and not attributable to secondary causes. Polysomnographically, it seems characterized by a high percentage of slow-wave (N3) sleep, decreased rapid eye movement sleep, cyclic alternating pattern, and arousals.ConclusionsPrimary menopausal insomnia is probably mediated through a mechanism separate from hot flashes, and one can occur without the other. Thermal dysregulation and sleep abnormalities of menopause are probably related to more general changes mediated through loss of estrogenic effects on neuronal modulation of energy metabolism, and more clinical direction is expected as this research field develops. Identification of sleep disorders in menopausal women is important, and polysomnographic evaluation is underused in both clinical and research evaluations of metabolic disturbances. (Endocr Pract. 2011; 17:122-131)  相似文献   

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During the 19th and early 20th centuries, ideas related to the possible origin in space of bioorganic molecules, or seeds, or even germs and organisms (and how they reached the Earth) included the Panspermia theory. Based on the idea of the eternity of life proposed by eminent physicists – such as Arrhenius and Kelvin – Panspermia is mainly divided into two branches: lithopanspermia (transport of germs inside stones traveling in space) and radiopanspermia (transport of spores by radiative pressure of stellar light). We point out some arguments to help to understand whether Panspermia could exist nowadays as the same theory defined one century ago. And we wonder about the kind of evolution Panspermia could have undergone during only a few decades. This possible evolution of the Panspermia concept takes place in the framework of the emergence of a new field, Bioastronomy. We present how this discipline has emerged during a few decades and how it has evolved. We consider its relationship with the progression of other scientific fields, and finally we examine how it is now included in different projects of space agencies. Bioastronomy researches having become more and more robust during the last few years, we emphasize several questions about new ideas and their consequences for the current hypothesis of Panspermia and of universal life.  相似文献   

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A statistical method is proposed for recognition of a bacterial species or for differentiation of two groups of bacterial strains. Comparison between two groups is done by the “t”-test. When the mean S-values (similarity value) of two groups are A and B, and the mean S-value for all possible combinations between strains of both groups is S, a condition necessary for defining the two groups as different species is to demonstrate the existence of equations A > S and B > S. Unless this condition is fulfilled, the two groups should be considered unseparable. The condition necessary for recognition of two groups as one species is to demonstrate the existence of equations A:= S and B = S. A few examples of the test were shown using the mycobacteria, and it was suggested that this statistical method is useful in the recognition of a species.  相似文献   

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Based on the hypotheses that (1) a physiological organization exists inside each activity of daily life and (2) the pattern of evolution of physiological variables is characteristic of each activity, pattern changes should be detected on daily life physiological recordings. The present study aims at investigating whether a simple segmentation method can be set up to detect pattern changes on physiological recordings carried out during daily life. Heart and breathing rates and skin temperature have been non-invasively recorded in volunteers following scenarios made of “daily life” steps (13 records). An observer, undergoing the scenario, wrote down annotations during the recording time. Two segmentation procedures have been compared to the annotations, a visual inspection of the signals and an automatic program based on a trends detection algorithm applied to one physiological signal (skin temperature). The annotations resulted in a total number of 213 segments defined on the 13 records, the best visual inspection detected less segments (120) than the automatic program (194). If evaluated in terms of the number of correspondences between the times marks given by annotations and those resulting from both physiologically based segmentations, the automatic program was better than the visual inspection. The mean time lags between annotation and program time marks remain <60 s (the precision of annotation times marks). We conclude that physiological variables time series recorded in common life conditions exhibit different successive patterns that can be detected by a simple trends detection algorithm. Theses sequences are coherent with the corresponding annotated activity.  相似文献   

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A generalized autocatalytic model for chiral polymerization is investigated in detail. Apart from enantiomeric cross-inhibition, the model allows for the autogenic (non-catalytic) formation of left and right-handed monomers from a substrate with reaction rates epsilon L and epsilon R, respectively. The spatiotemporal evolution of the net chiral asymmetry is studied for models with several values of the maximum polymer length, N. For N = 2, we study the validity of the adiabatic approximation often cited in the literature. We show that the approximation obtains the correct equilibrium values of the net chirality, but fails to reproduce the short time behavior. We show also that the autogenic term in the full N = 2 model behaves as a control parameter in a chiral symmetry-breaking phase transition leading to full homochirality from racemic initial conditions. We study the dynamics of the N--> infinity model with symmetric (epsilon L = epsilon R) autogenic formation, showing that it only achieves homochirality for epsilon > epsilon c, where epsilon c is an N-dependent critical value. For epsilon 相似文献   

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The strong version of the life-mind continuity thesis claims that mind can be understood as an enriched version of the same functional and organizational properties of life. Contrary to this view, in this paper I argue that mental phenomena offer distinctive properties, such as intentionality or representational content, that have no counterpart in the phenomenon of life, and that must be explained by appealing to a different level of functional and organizational principles. As a strategy, and following Maturana’s autopoietic theory of cognition, I introduce a conceptual distinction between mind and cognition. I argue that cognition corresponds to the natural behaviour that every living being exhibits in the realization of its existence, and that, viewed in that way, cognition is a dynamic process of structural coupling that, unlike mental phenomena, involves no representational contents. On the basis of this distinction, I try to show that while life suffices for cognition, it does not suffice for mind. That is, that the strong continuity is not between life and mind but between life and cognition.  相似文献   

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In several jurisdictions, sex offenders may be offered chemical castration as an alternative to further incarceration. In some, agreement to chemical castration may be made a formal condition of parole or release. In others, refusal to undergo chemical castration can increase the likelihood of further incarceration though no formal link is made between the two. Offering chemical castration as an alternative to further incarceration is often said to be partially coercive, thus rendering the offender’s consent invalid. The dominant response to this objection has been to argue that any coercion present in such cases is compatible with valid consent. In this article, we take a different tack, arguing that, even if consent would not be valid, offering chemical castration will often be supported by the very considerations that underpin concerns about consent: considerations of autonomy. This is because offering chemical castration will often increase the offender’s autonomy, both at the time the offer is made and in the future.  相似文献   

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Mercury (Hg) contamination in the Brazilian Amazon constitutes a serious environmental and public health issue. This study is part of the CARUSO Project, which uses an ecosystem approach to human health to examine the sources, transmission, and effects of Hg in the Brazilian Amazon, with a view to developing preventive intervention strategy. To date, studies have focused on measures of Hg exposure through fish consumption in relation to health effects; little attention has been given to quality of life (QoL). The objective of this study was to examine the relations between QoL and health perceptions, Hg exposure, sociodemographics, living conditions, and lifestyle in communities along the Tapajós River. A total of 456 adults from 13 villages were interviewed and provided hair samples for Hg analysis. Results showed that perceptions of QoL and health are relatively positive, despite elevated Hg exposure. Logistic regression analyses showed that a positive perception of QoL was associated with the absence of chronic illnesses, not smoking, fruit consumption, residing on the banks of the Tapajós, and living in an in-migrants’ community. The positive perception of health was associated with younger age, the absence of reported symptoms of chronic illnesses, and drinking alcoholic beverages. Cluster analysis revealed that the group that reported the highest QoL had a traditional lifestyle, involving daily fishing and high fish consumption. However, this traditional lifestyle is associated with elevated Hg levels and early reported symptoms potentially linked to Hg exposure. These findings underline the importance of understanding the factors underlying QoL to develop adequate strategies to reduce Hg exposure and promote well-being.  相似文献   

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Background

Research in the end-of-life context has explored the sense of dignity experienced by patients with advanced disease, examining the factors associated with it. Whereas certain perspectives regard dignity as an intrinsic quality, independent of external factors, in the clinical setting it is generally equated with the person’s sense of autonomy and control, and it appears to be related to patients’ quality of life. This study aims to explore the relationship between perceived dignity, autonomy and sense of control in patients at the end of life.

Methods

We conducted a systematic review and meta-ethnography using reciprocal translation and line-of-argument synthesis. The search strategy used MeSH terms in combination with free-text searching of the Pubmed, Web of Science, CINAHL, PsycINFO and Cochrane databases, from their inception until 2015. This identified 186 articles, after excluding duplicates. The inclusion criterion was primary qualitative studies in which dignity, autonomy and control at the end of life were explored. Studies were evaluated using the CASP guidelines.

Results

Twenty-one studies recording the experiences of 400 participants were identified. Three themes emerged: a) dignity mediated by the loss of functionality, linked to the loss of control; b) dignity as identity; and c) autonomy as a determining factor of perceived dignity, understood as the desire for control over the dying process and the desire for self-determination. We propose an explanatory model which highlights that those patients with an intrinsic sense of dignity maintained a positive view of themselves in the face of their illness.

Conclusion

This synthesis illustrates how dignity and autonomy are intertwined and can be perceived as a multidimensional concept, one that is close to the notion of personal identity. The ability to regard dignity as an intrinsic quality has a positive impact on patients, and the design of care strategies should take this into account.  相似文献   

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文章采用问卷调查的方式,从员工价值观取向、员工对组织文化建设的认可状况、员工的文化需求和期待等方面展开调查,把握员工对组织文化的整体认知情况,提出要从和谐社会的高度去构建医疗卫生机构组织文化,增强员工的归属感、幸福感,形成特色鲜明、内涵丰富的组织文化。  相似文献   

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