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PubMedDate not supplied

[Origin and evolution of life and intellect from the point of view of information processing].

Beginning of life and intellect on the Earth is determined by the fact that synthesis of semantic information about algorithms of chemical transformation for appointed classes of chemical compounds is not accompanied by the information synthesis, but is controlled by chance in genetic material. Genetic information as memorizing accidental choice always arises as a result of the environment interaction, when memorizing realization in the form of repeated reproduction occurs on the basis of processes radically different from those which created initial genetic chance. Such stepped synthesis of information has hierarchical character and it is described by entropy of different dimensions. Entropy is determined by conditional probabilities. Therefore as a form of life becomes complicated, the entropy is decreased within the limits of the given hierarchical step. The part of entropy depending on the number of elements of the system (cells, individuals, etc.) always increases in the memorizing process, i. e. life defines the maximum of entropy production (but not the minimum like in nature). This fact settles paradoxes of chance in Darwinism: as a result of entropy decrease within higher hierarchical step the simbiotic processes for more complex forms of life can arise with great probability. For instance, rapidity of evolution of human brain given by supplementary chance in the mechanism of fecundation under the conditions of biochemical pressure of androgenes both, on the brain development and on muscular force at the same time. Synthesis of information in the brain is determined by the same principles, but extremums of the thermo-dynamic potential (their analogues in logic) are based on an arbitrary system of axioms. As a whole life and intellect are not fluctuations pointed against entropy increases, but they arose according to spontaneous process of entropy development.

Biological Evolution↗
PubMed2003

[Francis Bacon on the origin and preservation of life: theory and experiments].

The paper analyses Bacon's views of life, as contained in De Sapientia Veterum, Historia vitae et mortis, and in a newly published manuscript, entitled De vijs mortis. Bacon saw the prolongation of life as one of the main goals of science and medicine, According to him, life is the result of the action of spirits on matter. In order to preserve life, it is necessary to investigate various kinds of generation, notably, those which occurr without seeds. The study of putrefaction is also crucial for the prolongation of life.

England↗
PubMed1999

A nonhyperthermophilic common ancestor to extant life forms.

The G+C nucleotide content of ribosomal RNA (rRNA) sequences is strongly correlated with the optimal growth temperature of prokaryotes. This property allows inference of the environmental temperature of the common ancestor to all life forms from knowledge of the G+C content of its rRNA sequences. A model of sequence evolution, assuming varying G+C content among lineages and unequal substitution rates among sites, was devised to estimate ancestral base compositions. This method was applied to rRNA sequences of various species representing the major lineages of life. The inferred G+C content of the common ancestor to extant life forms appears incompatible with survival at high temperature. This finding challenges a widely accepted hypothesis about the origin of life.

Animals↗
PubMed2001

Cybernetic formulation of the definition of life.

A definition of life (a living individual) in cybernetic terms is proposed. In this formulation, life (a living individual) is defined as a network of inferior negative feedbacks (regulatory mechanisms) subordinated to (being at service of) a superior positive feedback (potential of expansion). It is suggested that this definition is the minimal definition, necessary and sufficient, for life to be distinguished from inanimate phenomena and, as such, it describes the essence of life. Subsequently, a quantitative expression for the amount of the biologically relevant ("purposeful") information (as opposed to the amount of information in the thermodynamic sense) is proposed. This is followed by the application of the formulated approach to different phenomena of a dubious status existing presently on the Earth as well as to the process of origination of life on our planet.

Animals↗
PubMed2000

The quality of life of women of Chinese origin.

This paper draws upon qualitative data to explore the quality of life of Chinese mothers with preschool children in the central part of Manchester. In doing this it considers their own self-reported health conditions. Both semi-structured and conversational face-to-face interviews were used with mothers in their homes. The names of Chinese mothers were drawn from the immunization records of the Health Authority and Hospital Trust of Central Manchester. The final interview sample of 30 had a Chinese surname in the record. 'Lee' as a surname was excluded because it was used both by Chinese and English people. The mothers' socio-economic background and their quality of life in terms of work conditions and leisure, housing and residential environment, marital support and life satisfaction were examined. The findings indicate that since they settled in the United Kingdom, the women have been under great psychological stress from a variety of sources. These sources included hardship and overwork, poverty and deprivation, poor social support and social isolation, unhappy family relationships, gambling husbands and domestic violence, together with language and cultural difficulties. All of these contributed to poor quality of living standards as well as indirectly causing negative psychosocial health outcomes. The unsatisfactory self-reported health conditions and poor quality of life of Chinese mothers were naturally interrelated and might be determined by the disadvantages of migration. However, the mothers themselves expressed little satisfaction with the health services and it may be that improvements are necessary in this area to ameliorate some of the disadvantages of migration.

Journal Article↗
PubMed2002

Childhood growth and coronary heart disease in later life.

Coronary heart disease (CHD) originates early in life and numerous studies have shown inverse associations between body size at birth and CHD in adult life. Recently it has been shown that the increased risk for CHD associated with a small body size at birth is modified by growth during childhood. The greatest risk for CHD is noted in individuals with small body size at birth and who 'catch-up' in weight and body size during childhood. An increase in body weight and body mass index during the first year of life is however associated with a reduced risk of CHD. These recent findings add to the evidence that optimizing early growth is an important area in primary prevention of CHD. There are several potential mechanisms explaining the association between a non-optimal early growth and CHD. Behavioral, physiological, hormonal and genetic factors influence growth. Although socio-economic factors influence the risk of CHD, the association between slow fetal growth and CHD is not caused by confounding socio-economic factors. Biological programming - the process whereby a stimulus during critical periods of development has long lasting or lifelong effects on metabolism - is proposed to mediate the effects between early growth and adult diseases.

Adult↗
PubMed1997

Major "anastrophes" in the origin and early evolution of biological energy conversion.

The metabolism of living organisms has long been usefully divided into anabolism and catabolism. Anabolism is constructive, being concerned with the assembly of complex molecules, whereas catabolism is destructive in the sense that it involves the degradation of molecules. In addition to the well-known word catastrophe for sudden, drastic destruction and its consequences, it has been found practical to introduce in the evolutionary context the word "anastrophe" (an old greek word for turning back, in the opposite direction-from anastrephein, where ana = back and strephein = to turn) to cover sudden, drastic constructive events and their consequences. Mutations in genes and genomes giving selective advantage to an organism are typical anastrophic events. A single site mutation in a gene coding for a protein may be good, neutral or bad, or anastrophic, neutral or catastrophic, respectively, for the organism. The consequence of an anastrophic mutation may be a decisive first step on the long way to a new species, whereas a catastrophic mutation may lead to major cell damage or death. This example of the use of the anastrophe concept in biological evolution leads to the question about its applicability to other parts and paths of the cosmic evolutionary process, such as physical, chemical, social and cultural evolution. Here it will be mainly considered in connection with the energy conversion aspects of the chemical evolution leading to the origin of life and of the subsequent early biological evolution. More specifically, it will be attempted to describe possible major anastrophes in energy conversion both before and after the first occurrence of life on earth.

Animals↗
PubMed1991

Origin of fatty acid synthesis: thermodynamics and kinetics of reaction pathways.

The primitiveness of contemporary fatty acid biosynthesis was evaluated by using the thermodynamics and kinetics of its component reactions to estimate the extent of its dependence on powerful and selective catalysis by enzymes. Since this analysis indicated that the modern pathway is not primitive because it requires sophisticated enzymatic catalysis, we here propose an alternative pathway of primitive fatty acid synthesis that uses glycolaldehyde as a substrate. In contrast to the modern pathway, this primitive pathway is not dependent on an exogenous source of phosphoanhydride energy (ATP). Furthermore, the chemical spontaneity of its reactions suggests that it could have been readily catalyzed by the rudimentary biocatalysts available at an early stage in the origin of life.

Acetaldehyde↗
PubMed1996

Synthesis of RNA oligomers on heterogeneous templates.

The concept of an RNA world in the chemical origin of life is appealing, as nucleic acids are capable of both information storage and acting as templates that catalyse the synthesis of complementary molecules. Template-directed synthesis has been demonstrated for homogeneous oligonucleotides that, like natural nucleic acids, have 3',5' linkages between the nucleotide monomers. But it seems likely that prebiotic routes to RNA-like molecules would have produced heterogeneous molecules with various kinds of phosphodiester linkages and both linear and cyclic nucleotide chains. Here we show that such heterogeneity need be no obstacle to the templating of complementary molecules. Specifically, we show that heterogeneous oligocytidylates, formed by the montmorillonite clay-catalysed condensation of actuated monomers, can serve as templates for the synthesis of oligoguanylates. Furthermore, we show that oligocytidylates that are exclusively 2',5'-linked can also direct synthesis of oligoguanylates. Such heterogeneous templating reactions could have increased the diversity of the pool of protonucleic acids from which life ultimately emerged.

Biopolymers↗
PubMedDate not supplied

The lipid world.

The continuity of abiotically formed bilayer membranes with similar structures in contemporary cellular life, and the requirement for microenvironments in which large and small molecules could be compartmentalized, support the idea that amphiphilic boundary structures contributed to the emergence of life. As an extension of this notion, we propose here a 'Lipid World' scenario as an early evolutionary step in the emergence of cellular life on Earth. This concept combines the potential chemical activities of lipids and other amphiphiles, with their capacity to undergo spontaneous self-organization into supramolecular structures such as micelles and bilayers. In particular, the documented chemical rate enhancements within lipid assemblies suggest that energy-dependent synthetic reactions could lead to the growth and increased abundance of certain amphiphilic assemblies. We further propose that selective processes might act on such assemblies, as suggested by our computer simulations of mutual catalysis among amphiphiles. As demonstrated also by other researchers, such mutual catalysis within random molecular assemblies could have led to a primordial homeostatic system displaying rudimentary life-like properties. Taken together, these concepts provide a theoretical framework, and suggest experimental tests for a Lipid World model for the origin of life.

Catalysis↗