A Review of Ideas Concerning Life Origin

NASA Astrophysics Data System (ADS)

Gindilis, L. M.

2014-10-01

Since the times of Antiquity the and for a long time the idea of self-origination of life was the dominant one. It reappeared again after microorganisms were discovered (XVII century). The possibility of abiogenesis at microbial level was discussed for more than a century. Pateur demonstrated that spontaneous origination of microorganisms in sterile broth was due to those same microorganisms transported by dust particles. Thus proving that every form of life originates from the parental life form. So the question arises: how did the first microorganisms appear on the Earth. There are three possible versions: 1) accidental origination of a viable form; 2) primal organisms were transported to the Earth from outer space; 3) they were formed on the Earth in the process of prebiotic chemical evolution. We discuss the problems of prebiotic evolution from simple monomers up to living cells. An important item of nowadays conceptions of life origination is the hypothesis of the ancient world of RNA as possible precursor of life on Earth. The discovery in carbonaceous chondrites of traces of bacterial life evidences the existence of life in the Solar System even before the formation of the Earth. The idea of life as brought to the Earth out of Cosmos originated under the impression of self-origination hypothesis downfall. It went through several stages (Helmholtz, W. Thompson, XIX century; Arrhenius, early XX century; Hoyle and Wickramasinghe, second half of XX century) and presently evokes constantly growing interest. The panspermia theory does not solve the problem of origination of life, only moves it onto other planets. According to V.A. Mazur, the probability of accidental formation of RNA molecule is negligible not only on the Earth, but in the whole Universe over all the time span of its existence. But it is practically equal to unit in the domain formed at the inflation stage of the evolution of the Universe. A.D.Panov considered panspermia in the Galaxy at the level

Charles Darwin and the origin of life.

PubMed

Peretó, Juli; Bada, Jeffrey L; Lazcano, Antonio

2009-10-01

When Charles Darwin published The Origin of Species 150 years ago he consciously avoided discussing the origin of life. However, analysis of some other texts written by Darwin, and of the correspondence he exchanged with friends and colleagues demonstrates that he took for granted the possibility of a natural emergence of the first life forms. As shown by notes from the pages he excised from his private notebooks, as early as 1837 Darwin was convinced that "the intimate relation of Life with laws of chemical combination, & the universality of latter render spontaneous generation not improbable". Like many of his contemporaries, Darwin rejected the idea that putrefaction of preexisting organic compounds could lead to the appearance of organisms. Although he favored the possibility that life could appear by natural processes from simple inorganic compounds, his reluctance to discuss the issue resulted from his recognition that at the time it was possible to undertake the experimental study of the emergence of life.

Multiple origins of life

NASA Technical Reports Server (NTRS)

Raup, D. M.; Valentine, J. W.

1983-01-01

There is some indication that life may have originated readily under primitive earth conditions. If there were multiple origins of life, the result could have been a polyphyletic biota today. Using simple stochastic models for diversification and extinction, we conclude: (1) the probability of survival of life is low unless there are multiple origins, and (2) given survival of life and given as many as 10 independent origins of life, the odds are that all but one would have gone extinct, yielding the monophyletic biota we have now. The fact of the survival of our particular form of life does not imply that it was unique or superior.

Early evolution without a tree of life.

PubMed

Martin, William F

2011-06-30

Life is a chemical reaction. Three major transitions in early evolution are considered without recourse to a tree of life. The origin of prokaryotes required a steady supply of energy and electrons, probably in the form of molecular hydrogen stemming from serpentinization. Microbial genome evolution is not a treelike process because of lateral gene transfer and the endosymbiotic origins of organelles. The lack of true intermediates in the prokaryote-to-eukaryote transition has a bioenergetic cause.

Inversion Concept of the Origin of Life

NASA Astrophysics Data System (ADS)

Kompanichenko, V. N.

2012-06-01

The essence of the inversion concept of the origin of life can be narrowed down to the following theses: 1) thermodynamic inversion is the key transformation of prebiotic microsystems leading to their transition into primary forms of life; 2) this transformation might occur only in the microsystems oscillating around the bifurcation point under far-from-equilibrium conditions. The transformation consists in the inversion of the balance "free energy contribution / entropy contribution", from negative to positive values. At the inversion moment the microsystem radically reorganizes in accordance with the new negentropy (i.e. biological) way of organization. According to this approach, the origin-of-life process on the early Earth took place in the fluctuating hydrothermal medium. The process occurred in two successive stages: a) spontaneous self-assembly of initial three-dimensional prebiotic microsystems composed mainly of hydrocarbons, lipids and simple amino acids, or their precursors, within the temperature interval of 100-300°C (prebiotic stage); b) non-spontaneous synthesis of sugars, ATP and nucleic acids started at the inversion moment under the temperature 70-100°C (biotic stage). Macro- and microfluctuations of thermodynamic and physico-chemical parameters able to sustain this way of chemical conversion have been detected in several contemporary hydrothermal systems. A minimal self-sufficient unit of life on the early Earth was a community of simplest microorganisms (not a separate microorganism).

Microbes, Mineral Evolution, and the Rise of Microcontinents-Origin and Coevolution of Life with Early Earth.

PubMed

Grosch, Eugene G; Hazen, Robert M

2015-10-01

Earth is the most mineralogically diverse planet in our solar system, the direct consequence of a coevolving geosphere and biosphere. We consider the possibility that a microbial biosphere originated and thrived in the early Hadean-Archean Earth subseafloor environment, with fundamental consequences for the complex evolution and habitability of our planet. In this hypothesis paper, we explore possible venues for the origin of life and the direct consequences of microbially mediated, low-temperature hydrothermal alteration of the early oceanic lithosphere. We hypothesize that subsurface fluid-rock-microbe interactions resulted in more efficient hydration of the early oceanic crust, which in turn promoted bulk melting to produce the first evolved fragments of felsic crust. These evolved magmas most likely included sialic or tonalitic sheets, felsic volcaniclastics, and minor rhyolitic intrusions emplaced in an Iceland-type extensional setting as the earliest microcontinents. With the further development of proto-tectonic processes, these buoyant felsic crustal fragments formed the nucleus of intra-oceanic tonalite-trondhjemite-granitoid (TTG) island arcs. Thus microbes, by facilitating extensive hydrothermal alteration of the earliest oceanic crust through bioalteration, promoted mineral diversification and may have been early architects of surface environments and microcontinents on young Earth. We explore how the possible onset of subseafloor fluid-rock-microbe interactions on early Earth accelerated metavolcanic clay mineral formation, crustal melting, and subsequent metamorphic mineral evolution. We also consider environmental factors supporting this earliest step in geosphere-biosphere coevolution and the implications for habitability and mineral evolution on other rocky planets, such as Mars.

Organic Minerals in the Origin of Life

NASA Astrophysics Data System (ADS)

Benner, S.; Biondi, E.; Kim, H. J.

2017-12-01

Models for the origin of life are plagued by fundamental problems that, due to their difficulty, are called "paradoxes". One of these, known to anyone who has ever worked in a kitchen, is that organics, when given energy and left to itself, does not generate life. Rather, organics devolve to give tarry mixtures that become increasingly complex and increasingly less likely to support life (like asphalt). However, even if those mixtures escape devolution to create something useful for Darwinism, like building blocks for RNA, the water in which they must work is corrosive, leading to their destruction. Even if RNA is created, it is itself easily degraded. One current trend to manage those paradoxes turns to minerals in environments on early Earth. Inorganic minerals containing borate have now been shown to prevent the destruction of ribose (the R in RNA) and other carbohydrates essential for early Earth. Evaporite desert basins supplied with aqueous runoff from tourmaline-containing basalts are ideal environments for forming borate minerals, especially if they are made alkaline by serpentinizing peridotite. In the evaporite environments, drying cycles mitigate the destructive capability of water. Further, we have shown that phosphate is segregated from calcium (avoiding formation of relatively unreacted apatites) if magnesium and borate are present. Further, a common magnesium borophosphate (luneburgite) not only makes phosphate available for prebiotic synthesis, but selectively phosphorylates RNA building blocks as it releases borate to stabilize them against further degradation. Finally, a variety of minerals bind and stabilize RNA itself. Research in this area has also discovered organic minerals that might have been relevant to the origins of life on Earth. Such minerals are scarce on Earth today, since they are easily consumed by microbial communities. However, on a prebiotic Earth, organic minerals could have stored organic species as intermediates towards our

The early life origin theory in the development of cardiovascular disease and type 2 diabetes.

PubMed

Lindblom, Runa; Ververis, Katherine; Tortorella, Stephanie M; Karagiannis, Tom C

2015-04-01

Life expectancy has been examined from a variety of perspectives in recent history. Epidemiology is one perspective which examines causes of morbidity and mortality at the population level. Over the past few 100 years there have been dramatic shifts in the major causes of death and expected life length. This change has suffered from inconsistency across time and space with vast inequalities observed between population groups. In current focus is the challenge of rising non-communicable diseases (NCD), such as cardiovascular disease and type 2 diabetes mellitus. In the search to discover methods to combat the rising incidence of these diseases, a number of new theories on the development of morbidity have arisen. A pertinent example is the hypothesis published by David Barker in 1995 which postulates the prenatal and early developmental origin of adult onset disease, and highlights the importance of the maternal environment. This theory has been subject to criticism however it has gradually gained acceptance. In addition, the relatively new field of epigenetics is contributing evidence in support of the theory. This review aims to explore the implication and limitations of the developmental origin hypothesis, via an historical perspective, in order to enhance understanding of the increasing incidence of NCDs, and facilitate an improvement in planning public health policy.

The Limits of Life in the Deep Subsurface - Implications for the Origin of Life

NASA Astrophysics Data System (ADS)

Baross, John

2013-06-01

There are very few environments on Earth where life is absent. Microbial life has proliferated into habitats that span nearly every imaginable physico-chemical variable. Only the availability of liquid water and temperature are known to prevent the growth of organisms. The other extreme physical and chemical variables, such as pH, pressure, high concentrations of solutes, damaging radiation, and toxic metals, are life-prohibiting factors for most organisms but not for all. The deep subsurface environments span all of the extreme conditions encountered by life including habitat conditions not yet explored, such as those that combine high temperature, high and low pH and extreme pressures. Some of the ``extremophile'' microorganisms inhabiting the deep subsurface environments have been shown to be among the most ``ancient'' of extant life. Their genomes and physiologies have led to a broader understanding of the geological settings of early life, the most ancient energy pathways, and the importance of water/rock interactions and tectonics in the origin and early evolution of life. The case can now be made that deep subsurface environments contributed to life's origin and provided the habitat(s) for the earliest microbial communities. However, there is much more to be done to further our understanding on the role of moderate to high pressures and temperatures on the chemical and biochemical ``steps'' leading to life, and on the evolution and physiology of both ancient and present-day subsurface microbial communities.

Developmental origins of cardiovascular disease: Impact of early life stress in humans and rodents.

PubMed

Murphy, M O; Cohn, D M; Loria, A S

2017-03-01

The Developmental Origins of Health and Disease (DOHaD) hypothesizes that environmental insults during childhood programs the individual to develop chronic disease in adulthood. Emerging epidemiological data strongly supports that early life stress (ELS) given by the exposure to adverse childhood experiences is regarded as an independent risk factor capable of predicting future risk of cardiovascular disease. Experimental animal models utilizing chronic behavioral stress during postnatal life, specifically maternal separation (MatSep) provides a suitable tool to elucidate molecular mechanisms by which ELS increases the risk to develop cardiovascular disease, including hypertension. The purpose of this review is to highlight current epidemiological studies linking ELS to the development of cardiovascular disease and to discuss the potential molecular mechanisms identified from animal studies. Overall, this review reveals the need for future investigations to further clarify the molecular mechanisms of ELS in order to develop more personalized therapeutics to mitigate the long-term consequences of chronic behavioral stress including cardiovascular and heart disease in adulthood. Copyright © 2016 Elsevier Ltd. All rights reserved.

Early evolution without a tree of life

PubMed Central

2011-01-01

Life is a chemical reaction. Three major transitions in early evolution are considered without recourse to a tree of life. The origin of prokaryotes required a steady supply of energy and electrons, probably in the form of molecular hydrogen stemming from serpentinization. Microbial genome evolution is not a treelike process because of lateral gene transfer and the endosymbiotic origins of organelles. The lack of true intermediates in the prokaryote-to-eukaryote transition has a bioenergetic cause. This article was reviewed by Dan Graur, W. Ford Doolittle, Eugene V. Koonin and Christophe Malaterre. PMID:21714942

On the possibility of life on early Mars

NASA Technical Reports Server (NTRS)

Oberbeck, V. R.; Fogleman, G.

1990-01-01

Prebiotic reactants, liquid water, and temperatures low enough for organic compounds to be stable are requirements for the origination of life as we know it. Prebiotic reactants and sufficiently low temperatures were present on Mars before liquid water vanished. Early in this time period, however, large planetesimal impacts may have periodically sterilized Mars, pyrolyzed organic compounds, and interrupted chemical origination of life. However, the calculated time interval between such impacts on Mars was larger just before liquid water vanished 3.8 Gyr (billion years) ago than it was on earth just before life originated. Therefore, there should have been sufficient time for life to originate on Mars. Ideal sites to search for microfossils are in the heavily cratered terrain of Upper Noachian age. Craters and channels in this terrain may have been the sites of ancient lakes and streams that could have provided habitats for the first microorganisms.

Homochirality and the origin of life

NASA Astrophysics Data System (ADS)

Pohl, Robert; Leitner, J. J.; Firneis, M. G.

2012-05-01

Homochirality is generally considered a crucial signature for life on Earth, which uses left-handed amino acids and right-handed sugars. A mirror-image life, using right-handed amino acids and left- handed sugars, is perfectly conceivable and might have developed on another planet. Life which would simultaneously use both right- and left-handed forms of the same biological molecules is unlikely for geometrical reasons. Secondary peptide structures are not possible without one-handedness. Various theories try to explain the origin of homochirality. Physicists used as argument the phenomenon of parity violation discovered on 60Co, which does not explain homochirality on prebiotic substances. Astrophysicists suggested that the observed enantiomeric excesses could have been induced by circularly polarized light arising from dust scattering in regions of high mass star formations or even due to super nova remnants or pulsars. An extraterrestrial origin of homochiral substances is discusses as well as catalytic processes on early Earth using different mineral surfaces. Thermodynamics i.e. its 2nd law is considered to explain homochirality as consequence of increasing entropy. There are many questions not yet answered. The author looks forward to discuss some of them with interested scientists.

Environmental Adaptation from the Origin of Life to the Last Universal Common Ancestor

NASA Astrophysics Data System (ADS)

Cantine, Marjorie D.; Fournier, Gregory P.

2018-03-01

Extensive fundamental molecular and biological evolution took place between the prebiotic origins of life and the state of the Last Universal Common Ancestor (LUCA). Considering the evolutionary innovations between these two endpoints from the perspective of environmental adaptation, we explore the hypothesis that LUCA was temporally, spatially, and environmentally distinct from life's earliest origins in an RNA world. Using this lens, we interpret several molecular biological features as indicating an environmental transition between a cold, radiation-shielded origin of life and a mesophilic, surface-dwelling LUCA. Cellularity provides motility and permits Darwinian evolution by connecting genetic material and its products, and thus establishing heredity and lineage. Considering the importance of compartmentalization and motility, we propose that the early emergence of cellularity is required for environmental dispersal and diversification during these transitions. Early diversification and the emergence of ecology before LUCA could be an important pre-adaptation for life's persistence on a changing planet.

Early-Life Social Origins of Later-Life Body Weight: The Role of Socioeconomic Status and Health Behaviors over the Life Course

PubMed Central

Logan, Ellis Scott; Richman, Aliza

2014-01-01

Using the 1957-2004 data from the Wisconsin Longitudinal Study, we apply structural equation modeling to examine gender-specific effects of family socioeconomic status (SES) at age 18 on body weight at age 65. We further explore SES and health behaviors over the life course as mechanisms linking family background and later-life body weight. We find that early-life socioeconomic disadvantage is related to higher body weight at age 65 and a steeper weight increase between midlife and late life. These adverse effects are stronger among women than men. Significant mediators of the effect of parents' SES include adolescent body mass (especially among women) as well as exercise and SES in midlife. Yet, consistent with the critical period mechanism, the effect of early-life SES on late-life body weight persists net of all mediating variables. This study expands current understanding of life-course mechanisms that contribute to obesity and increase biological vulnerability to social disadvantage. PMID:24767590

Geochemistry and the origin of life

NASA Technical Reports Server (NTRS)

Kvenvolden, K. A.

1974-01-01

The origin of life on earth is examined from a viewpoint stressing the validity of the concept of chemical evolution. The different geological formations supporting the mechanisms of the theory are described; the stage of chemical evolution (preceding that of biological evolution) would have taken place from the time of the origin of the earth and meteorites, 4.6 billion years ago, to the early Precambrian period, about 3.2 billion years ago. Specific aspects of the problem discussed include amino acids from spark discharges and their comparison with the Murchison meteorite amino acids, the properties and theory of genesis of the carbonaceous complex within the cold Bokevelt meteorite, ammonion ion concentration in the primitive ocean, the oxygen isotope chemistry of ancient charts, the origin and rise of oxygen concentration in the earth's atmosphere, Precambrian microorganisms and evolutionary events prior to the origin of vascular plants, and biogenicity and significance of the oldest known stromatolites.

Cometary material and the origins of life on earth

NASA Technical Reports Server (NTRS)

Lazcano-Araujo, A.; Oro, J.

1981-01-01

The role of cometary material in determining the environmental conditions of the prebiotic earth is reviewed. The organic synthesis pathways that occur in dense interstellar clouds and in comets are examined, and complex organic molecules believed to exist (amino acids, carboxylic acids, purines, pyrimidines and hydrocarbons) based on spectral detections of degradation products are noted. Estimates of the amount of terrestrial volatiles of cometary origin that may have been acquired in collisions during the early history of the earth are considered, and shown to dominate any estimated contributions to terrestrial carbon from other extraterrestrial sources. Current evidence that the origin and early evolution of life began about four billion years ago is discussed in relation to the cometary bombardment processes occurring at the time and the resultant shock waves, reducing atmospheres and reactive chemical species. It is thus concluded that comets contributed significantly to the processes of chemical evolution necessary for the emergence of life on earth.

Chance of Necessity: Modeling Origins of Life

NASA Technical Reports Server (NTRS)

Pohorille, Andrew

2006-01-01

The fundamental nature of processes that led to the emergence of life has been a subject of long-standing debate. One view holds that the origin of life is an event governed by chance, and the result of so many random events is unpredictable. This view was eloquently expressed by Jacques Monod in his book Chance or Necessity. In an alternative view, the origin of life is considered a deterministic event. Its details need not be deterministic in every respect, but the overall behavior is predictable. A corollary to the deterministic view is that the emergence of life must have been determined primarily by universal chemistry and biochemistry rather than by subtle details of environmental conditions. In my lecture I will explore two different paradigms for the emergence of life and discuss their implications for predictability and universality of life-forming processes. The dominant approach is that the origin of life was guided by information stored in nucleic acids (the RNA World hypothesis). In this view, selection of improved combinations of nucleic acids obtained through random mutations drove evolution of biological systems from their conception. An alternative hypothesis states that the formation of protocellular metabolism was driven by non-genomic processes. Even though these processes were highly stochastic the outcome was largely deterministic, strongly constrained by laws of chemistry. I will argue that self-replication of macromolecules was not required at the early stages of evolution; the reproduction of cellular functions alone was sufficient for self-maintenance of protocells. In fact, the precise transfer of information between successive generations of the earliest protocells was unnecessary and could have impeded the discovery of cellular metabolism. I will also show that such concepts as speciation and fitness to the environment, developed in the context of genomic evolution also hold in the absence of a genome.

Original Research: Metabolic alterations from early life thyroxine replacement therapy in male Ames dwarf mice are transient.

PubMed

Darcy, Justin; Fang, Yimin; Hill, Cristal M; McFadden, Sam; Sun, Liou Y; Bartke, Andrzej

2016-10-01

Ames dwarf mice are exceptionally long-lived due to a Prop1 loss of function mutation resulting in deficiency of growth hormone, thyroid-stimulating hormone and prolactin. Deficiency in thyroid-stimulating hormone and growth hormone leads to greatly reduced levels of circulating thyroid hormones and insulin-like growth factor 1, as well as a reduction in insulin secretion. Early life growth hormone replacement therapy in Ames dwarf mice significantly shortens their longevity, while early life thyroxine (T4) replacement therapy does not. Possible mechanisms by which early life growth hormone replacement therapy shortens longevity include deleterious effects on glucose homeostasis and energy metabolism, which are long lasting. A mechanism explaining why early life T4 replacement therapy does not shorten longevity remains elusive. Here, we look for a possible explanation as to why early life T4 replacement therapy does not impact longevity of Ames dwarf mice. We found that early life T4 replacement therapy increased body weight and advanced the age of sexual maturation. We also find that early life T4 replacement therapy does not impact glucose tolerance or insulin sensitivity, and any deleterious effects on oxygen consumption, respiratory quotient and heat production are transient. Lastly, we find that early life T4 replacement therapy has long-lasting effects on bone mineral density and bone mineral content. We suggest that the transient effects on energy metabolism and lack of effects on glucose homeostasis are the reasons why there is no shortening of longevity after early life T4 replacement therapy in Ames dwarf mice. © 2016 by the Society for Experimental Biology and Medicine.

The case for a Martian origin for Earth life

NASA Astrophysics Data System (ADS)

Benner, Steven A.; Kim, Hyo-Joong

2015-09-01

Classical prebiotic chemistry, which has for the last half century explored the reactivity of small organic molecules in glassware environments under the control of chemists, has left unanswered multiple paradoxes with respect to the origins of life. Many of these can be approached, and possibly solved, by placing organic molecular reactivity within the context of the rocks, minerals, hydrosphere, and atmosphere of a prebiotic earth. This new direction in prebiotic chemistry is discussed here, with special emphasis on the role of minerals in constraining the inherent propensity of carbohydrates to devolve to form unproductively complex mixtures of materials. We focus in particular on minerals containing the elements boron and molybdenum, which is produced in discontinuous synthesis model for the emergence of RNA as the first Darwinian molecule. Further, the role of desert environments to manage the "water paradox" is discussed in the context of many classes of processes that have been proposed to deliver RNA under prebiotic conditions. If current models are correct to suggest that early Earth may have been largely flooded at the time when life originated, Then those desert environments may not have been available. However, the inventory of water on Mars has always been less than on Earth and, as Kirschvink has pointed out, intercourse between the two planets was frequent during the time when life is emerging on either planets. This suggests that desert like environments may have been present on early Mars, if they were not present on early Earth.

Is there a single origin of life?

NASA Astrophysics Data System (ADS)

Soffen, Gerald A.

The emergence of the first life on the earth is now established as an early event, and closely related to the evolving earth. Laboratory experiments examining possible chemical events have revealed a multitude of plausible pathways. Lack of knowledge of the primitive terrestrial conditions contemporary with the evolving prebolic organic chemistry limits reconstruction techniques. The primitive earth's aqueous history is essential to unraveling this problem. Based on our current knowledge of other planets of the solar system, we do not expect close analogues to the early earth. We still do not know if there was a second origin or if only earth has life. This may depend upon the question of the survival of information bearing chemical systems in a dynamic or chaotic environment and the chemical protection afforded within such a system. Water is the central molecule of controversy: the blessing and the curse of the chemist. New and novel chemical mechanisms and systems abound.

Could the early environment of Mars have supported the development of life?

NASA Technical Reports Server (NTRS)

Mckay, Christopher P.; Stoker, Carol R.

1990-01-01

The environment of Mars and its correlation to the origin of life on earth are examined. Evidence of liquid water and nitrogen on early Mars is discussed. The similarities between the early Mars and early earth environments are described.

The Intestinal Microbiome in Early Life: Health and Disease

PubMed Central

Arrieta, Marie-Claire; Stiemsma, Leah T.; Amenyogbe, Nelly; Brown, Eric M.; Finlay, Brett

2014-01-01

Human microbial colonization begins at birth and continues to develop and modulate in species abundance for about 3 years, until the microbiota becomes adult-like. During the same time period, children experience significant developmental changes that influence their health status as well as their immune system. An ever-expanding number of articles associate several diseases with early-life imbalances of the gut microbiota, also referred to as gut microbial dysbiosis. Whether early-life dysbiosis precedes and plays a role in disease pathogenesis, or simply originates from the disease process itself is a question that is beginning to be answered in a few diseases, including IBD, obesity, and asthma. This review describes the gut microbiome structure and function during the formative first years of life, as well as the environmental factors that determine its composition. It also aims to discuss the recent advances in understanding the role of the early-life gut microbiota in the development of immune-mediated, metabolic, and neurological diseases. A greater understanding of how the early-life gut microbiota impacts our immune development could potentially lead to novel microbial-derived therapies that target disease prevention at an early age. PMID:25250028

Energy sources, self-organization, and the origin of life.

PubMed

Boiteau, Laurent; Pascal, Robert

2011-02-01

The emergence and early developments of life are considered from the point of view that contingent events that inevitably marked evolution were accompanied by deterministic driving forces governing the selection between different alternatives. Accordingly, potential energy sources are considered for their propensity to induce self-organization within the scope of the chemical approach to the origin of life. Requirements in terms of quality of energy locate thermal or photochemical activation in the atmosphere as highly likely processes for the formation of activated low-molecular weight organic compounds prone to induce biomolecular self-organization through their ability to deliver quanta of energy matching the needs of early biochemical pathways or the reproduction of self-replicating entities. These lines of reasoning suggest the existence of a direct connection between the free energy content of intermediates of early pathways and the quanta of energy delivered by available sources of energy.

Energy Sources, Self-organization, and the Origin of Life

NASA Astrophysics Data System (ADS)

Boiteau, Laurent; Pascal, Robert

2011-02-01

The emergence and early developments of life are considered from the point of view that contingent events that inevitably marked evolution were accompanied by deterministic driving forces governing the selection between different alternatives. Accordingly, potential energy sources are considered for their propensity to induce self-organization within the scope of the chemical approach to the origin of life. Requirements in terms of quality of energy locate thermal or photochemical activation in the atmosphere as highly likely processes for the formation of activated low-molecular weight organic compounds prone to induce biomolecular self-organization through their ability to deliver quanta of energy matching the needs of early biochemical pathways or the reproduction of self-replicating entities. These lines of reasoning suggest the existence of a direct connection between the free energy content of intermediates of early pathways and the quanta of energy delivered by available sources of energy.

Osteoporosis in survivors of early life starvation.

PubMed

Weisz, George M; Albury, William R

2013-01-01

The objective of this study was to provide evidence for the association of early life nutritional deprivation and adult osteoporosis, in order to suggest that a history of such deprivation may be an indicator of increased risk of osteoporosis in later life. The 'fetal programming' of a range of metabolic and cardiovascular disorders in adults was first proposed in the 1990s and more recently extended to disorders of bone metabolism. Localised famines during World War II left populations in whom the long-term effects of maternal, fetal and infantile nutritional deprivation were studied. These studies supported the original concept of 'fetal programming' but did not consider bone metabolism. The present paper offers clinical data from another cohort of World War II famine survivors - those from the Holocaust. The data presented here, specifically addressing the issue of osteoporosis, report on 11 Holocaust survivors in Australia (five females, six males) who were exposed to starvation in early life. The cases show, in addition to other metabolic disorders associated with early life starvation, various levels of osteoporosis, often with premature onset. The cohort studied is too small to support firm conclusions, but the evidence suggests that the risk of adult osteoporosis in both males and females is increased by severe starvation early in life - not just in the period from gestation to infancy but also in childhood and young adulthood. It is recommended that epidemiological research on this issue be undertaken, to assist planning for the future health needs of immigrants to Australia coming from famine affected backgrounds. Pending such research, it would be prudent for primary care health workers to be alert to the prima facie association between early life starvation and adult osteoporosis, and to take this factor into account along with other indicators when assessing a patient's risk of osteoporosis in later life.

Origins of Early Adolescents' Hope: Personality, Parental Attachment, and Stressful Life Events

ERIC Educational Resources Information Center

Otis, Kristin L.; Huebner, E. Scott; Hills, Kimberly J.

2016-01-01

Psychology has recently increased attention to identifying psychological qualities in individuals that indicate positive mental health, such as hope. In an effort to understand further the origins of hope, we examined the relations among parental attachment, stressful life events, personality variables, and hope in a sample of 647 middle school…

The origin of life in alkaline hydrothermal vents

NASA Astrophysics Data System (ADS)

Sojo, V.; Herschy, B.; Whicher, A.; Camprubí, E.; Lane, N.

2016-12-01

The origin of life remains one of Science's greatest unresolved questions. The answer will no doubt involve almost all the basic disciplines, including Physics, Chemistry, Astronomy, Geology, and Biology. Chiefly, it is the link between the latter two that must be elucidated: how geochemistry gave rise to biochemistry. Serpentinizing systems such as alkaline hydrothermal vents offer the most robust combination of conditions to have hosted the origin of life on the early Earth, while bearing many parallels to modern living cells. Stark gradients of concentration, pH, oxidation/reduction, and temperature provided the ability to synthesise and concentrate organic products, drive polymerisation reactions, and develop an autotrophic lifestyle independent of foreign sources of organics. In the oxygen-depleted waters of the Hadean, alkaline vents would have acted as electrochemical flow reactors, in which alkaline fluids saturated in H2 mixed with the relatively acidic CO2-rich waters of the ocean, through interconnected micropores made of thin inorganic walls containing catalytic Fe(Ni)S minerals. Perhaps not coincidentally, the unit cells of these Fe(Ni)S minerals closely resemble the active sites of crucial ancestral bioenergetic enzymes. Meanwhile, differences in pH across the thin barriers produced natural proton gradients similar to those used for carbon fixation in modern archaea and bacteria. At the earliest stages, the problem of the origin of life is the problem of the origin of carbon fixation. I will discuss work over the last decade that suggests several possible hypotheses for how simple one-carbon molecules could have given rise to more complex organics, particularly within a serpentinizing alkaline hydrothermal vent. I will discuss the perplexing differences in carbon and energy metabolism in methanogenic archaea and acetogenic bacteria, thought to be the earliest representatives of each domain, to propose a possible ancestral mechanism of CO2 reduction in

Records of our Early Biosphere Illuminate our Origins and Guide our Search for Life Beyond Earth

NASA Technical Reports Server (NTRS)

DesMarais, David J.

2003-01-01

A scientific "mission of exploration to early Earth" will help us chart the distribution of life elsewhere. We must discriminate between attributes of biospheres that are universal versus those attributes that represent principally the outcomes of long-term survival specifically on Earth. In addition to the basic physics and chemistry of matter, the geologic evolution of rocky habitable planets and their climates might be similar elsewhere in the Universe. Certain key agents that drive long-term environmental change (e.g., stellar evolution, impacts, geothermal heat flow, tectonics, etc.) can help us to reconstruct ancient climates and to compare their evolution among populations of Earth- like planets. Early Earth was tectonically more active than today and therefore it exhaled reduced chemical species into the more oxidized surface environment at greater rates. This tectonic activity thus sustained oxidation-reduction reactions that provided the basis for the development of biochemical pathways that harvest chemical energy ("bioenergetics"). Most examples of bioenergetics today that extract energy by reacting oxidized and reduced chemicals in the environment were likely more pervasive among our microbial ancestors than are the presently known examples of photosynthesis. The geologic rock record indicates that, as early as 3.5 billion years ago (3.5 Ga), microbial biofilms were widespread within the coastal environments of small continents and tectonically unstable volcanic islands. Non oxygen-producing (non-oxygenic) photosynthesis preceded oxygenic photosynthesis, but all types of photosynthesis contributed substantially to the long-term increase in global primary biological productivity. Evidence of photosynthesis is tentative by 3.5 Ga and compelling by 2.7 Ga. Evidence of oxygenic photosynthesis is strong by 2.7 Ga and compelling by 2.3 Ga. These successive innovations transformed life from local communities that survived principally by catalyzing chemical

Re-conceptualizing the origins of life

NASA Astrophysics Data System (ADS)

Walker, Sara I.; Packard, N.; Cody, G. D.

2017-11-01

Over the last several hundred years of scientific progress, we have arrived at a deep understanding of the non-living world. We have not yet achieved an analogous, deep understanding of the living world. The origins of life is our best chance at discovering scientific laws governing life, because it marks the point of departure from the predictable physical and chemical world to the novel, history-dependent living world. This theme issue aims to explore ways to build a deeper understanding of the nature of biology, by modelling the origins of life on a sufficiently abstract level, starting from prebiotic conditions on Earth and possibly on other planets and bridging quantitative frameworks approaching universal aspects of life. The aim of the editors is to stimulate new directions for solving the origins of life. The present introduction represents the point of view of the editors on some of the most promising future directions. This article is part of the themed issue 'Reconceptualizing the origins of life'.

Early life nutritional programming of health and disease in The Gambia.

PubMed

Moore, S E

2016-04-01

Exposures during the early life (periconceptional, prenatal and early postnatal) period are increasingly recognized as playing an important role in the aetiology of chronic non-communicable diseases (NCD), including coronary heart disease, stroke, hypertension, Type 2 diabetes and osteoporosis. The 'Developmental Origins of Health and Disease' (DOHaD) hypothesis states that these disorders originate through unbalanced nutrition early in life and risk is highest when there is a 'mismatch' between the early- and later-life environments. Thus, the DOHaD hypothesis would predict highest risk in countries where an excess of infants are born with low birth weight and where there is a rapid transition to nutritional adequacy or excess in adulthood. Here, I will review data from work conducted in rural Gambia, West Africa. Using demographic data dating back to the 1940s, the follow-up of randomized controlled trials of nutritional supplementation in pregnancy and the 'experiment of nature' that seasonality in this region provides, we have investigated the DOHaD hypothesis in a population with high rates of maternal and infant under-nutrition, a high burden from infectious disease, and an emerging risk of NCDs.

Until the sun dies. [Book on origin of universe, life and intelligence on earth

NASA Technical Reports Server (NTRS)

Jastrow, R.

1977-01-01

This book gives a popular account of the forces that have shaped human beings into their present form and created the power of human intelligence, and considers the prospects for intelligent life on other planets in the solar system and elsewhere in the universe. The chain of events leading from the big bang to the origin of life on earth is reviewed together with the observations that established the expansion of the universe. Philosophical difficulties with the concept of a universe that has both a beginning and an end are pondered, steady-state cosmology is briefly explained, and the discovery of the relict microwave background is discussed. The formation of the solar system is recounted along with the scientific view of the origin of terrestrial life. Attention is given to the origin of cells and the evolution of oxygen-breathing life, multicelled creatures, armored animals, fishes, amphibians, early reptiles, dinosaurs, and mammals. The development of mammalian intelligence is traced from the early tree dwellers through monkeys, apes, ape men, humanoid tool makers, and primitive members of the genus Homo, to Homo sapiens. Possible evidence for the existence of life on Mars is evaluated together with prospects for communication or other contact with extraterrestrial intelligence.

The habitat and nature of early life.

PubMed

Nisbet, E G; Sleep, N H

2001-02-22

Earth is over 4,500 million years old. Massive bombardment of the planet took place for the first 500-700 million years, and the largest impacts would have been capable of sterilizing the planet. Probably until 4,000 million years ago or later, occasional impacts might have heated the ocean over 100 degrees C. Life on Earth dates from before about 3,800 million years ago, and is likely to have gone through one or more hot-ocean 'bottlenecks'. Only hyperthermophiles (organisms optimally living in water at 80-110 degrees C) would have survived. It is possible that early life diversified near hydrothermal vents, but hypotheses that life first occupied other pre-bottleneck habitats are tenable (including transfer from Mars on ejecta from impacts there). Early hyperthermophile life, probably near hydrothermal systems, may have been non-photosynthetic, and many housekeeping proteins and biochemical processes may have an original hydrothermal heritage. The development of anoxygenic and then oxygenic photosynthesis would have allowed life to escape the hydrothermal setting. By about 3,500 million years ago, most of the principal biochemical pathways that sustain the modern biosphere had evolved, and were global in scope.

Chemical Origins of Life

ERIC Educational Resources Information Center

Fox, J. Lawrence

1972-01-01

Reviews ideas and evidence bearing on the origin of life. Shows that evidence to support modifications of Oparin's theories of the origin of biological constituents from inorganic materials is accumulating, and that the necessary components are readily obtained from the simple gases found in the universe. (AL)

The early Earth atmosphere and early life catalysts.

PubMed

Ramírez Jiménez, Sandra Ignacia

2014-01-01

Homochirality is a property of living systems on Earth. The time, the place, and the way in which it appeared are uncertain. In a prebiotic scenario two situations are of interest: either an initial small bias for handedness of some biomolecules arouse and progressed with life, or an initial slight excess led to the actual complete dominance of the known chiral molecules. A definitive answer can probably never be given, neither from the fields of physics and chemistry nor biology. Some arguments can be advanced to understand if homochirality is necessary for the initiation of a prebiotic homochiral polymer chemistry, if this homochirality is suggesting a unique origin of life, or if a chiral template such as a mineral surface is always required to result in an enantiomeric excess. A general description of the early Earth scenario will be presented in this chapter, followed by a general description of some clays, and their role as substrates to allow the concentration and amplification of some of the building blocks of life.

Attic still life southsoutheast looking northnorthwest. Shows an early toilet, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Attic still life south-southeast looking north-northwest. Shows an early toilet, what is possibly the original front door, and a lead lined reservoir. Also shows the attic framing. - Samuel P. Grindle House, 13 School Street, Castine, Hancock County, ME

Early Life Exposures and Cancer

Cancer.gov

Early-life events and exposures have important consequences for cancer development later in life, however, epidemiological studies of early-life factors and cancer development later in life have had significant methodological challenges.

Conceptualizing the origin of life in terms of evolution

NASA Astrophysics Data System (ADS)

Takeuchi, N.; Hogeweg, P.; Kaneko, K.

2017-11-01

In this opinion piece, we discuss how to place evolution in the context of origin-of-life research. Our discussion starts with a popular definition: `life is a self-sustained chemical system capable of undergoing Darwinian evolution'. According to this definition, the origin of life is the same as the origin of evolution: evolution is the `end' of the origin of life. This perspective, however, has a limitation, in that the ability of evolution in and of itself is insufficient to explain the origin of life as we know it, as indicated by Spiegelman's and Lincoln and Joyce's experiments. This limitation provokes a crucial question: What conditions are required for replicating systems to evolve into life? From this perspective, the origin of life includes the emergence of life through evolution: evolution is a `means' of the origin of life. After reviewing Eigen's pioneering work on this question, we mention our ongoing work suggesting that a key condition might be conflicting multi-level evolution. Taken together, there are thus two questions regarding the origin of life: how evolution gets started, and how evolution produces life. Evolution is, therefore, at the centre of the origin of life, where the two lines of enquiry must meet. This article is part of the themed issue 'Reconceptualizing the origins of life'.

Early-Life Nutritional Programming of Health and Disease in The Gambia.

PubMed

Moore, Sophie E

2017-01-01

Exposures during early life are increasingly being recognised as factors that play an important role in the aetiology of chronic non-communicable diseases (NCDs). The "Developmental Origins of Health and Disease" (DOHaD) hypothesis asserts that adverse early-life exposures - most notably unbalanced nutrition - leads to an increased risk for a range of NCDs and that disease risk is highest when there is a "mismatch" between the early- and later-life environments. Thus, the DOHaD hypothesis would predict highest risk in settings undergoing a rapid nutrition transition. We investigated the link between early-life nutritional exposures and long-term health in rural Gambia, West Africa. Using demographic data dating back to the 1940s, the follow-up of randomised controlled trials of nutritional supplementation in pregnancy, and the "experiment of nature" that seasonality in this region provides, we investigated the DOHaD hypothesis in a population with high rates of maternal and infant under-nutrition, a high burden from infectious disease, and an emerging risk of NCDs. Key Messages: Our work in rural Gambia suggests that in populations with high rates of under-nutrition in early life, the immune system may be sensitive to nutritional deficiencies early in life, resulting in a greater susceptibility to infection-related morbidity and mortality. © 2017 S. Karger AG, Basel.

Molecules from Space and the Origin of Life

NASA Technical Reports Server (NTRS)

Bernstein Max P.; Sandford, Scott A.; Allamandola, Louis J.; DeVincenzi, Donald (Technical Monitor)

1999-01-01

There is a growing concensus among space scientists that frozen molecules from space helped to make the Earth the pleasant place that it is today, and helped Life start on Earth, and perhaps elsewhere. The chain of logic that led scientists to posit a connection between extraterrestrial molecules and the origin of life is as follows. 1) The rapidity with which life arose demands that conditions on Earth were conducive to the formation of life very early on. 2) There is reason to believe that comets and meteorites fell oil the Earth from its inception. 3) We now know that comets and meteorites are replete with complex organic compounds, some of which resemble those in living systems. 4) Perhaps the input of molecules from comets and meteorites provided crucial constituents to the primordial soup and Jump started life on Earth. 5) These molecules formed out in deep space long before the Earth ever existed, by processes that we can reproduce in the laboratory. 6) The fact that organic molecules are seen by astronomers throughout our galaxy and in others makes it seem likely that they were (and are) available to help start life in other planetary systems.

Exploring the Origin, Extent, and Future of Life

NASA Astrophysics Data System (ADS)

Bertka, Constance M.

2009-09-01

1. Astrobiology in societal context Constance Bertka; Part I. Origin of Life: 2. Emergence and the experimental pursuit of the origin of life Robert Hazen; 3. From Aristotle to Darwin, to Freeman Dyson: changing definitions of life viewed in historical context James Strick; 4. Philosophical aspects of the origin-of-life problem: the emergence of life and the nature of science Iris Fry; 5. The origin of terrestrial life: a Christian perspective Ernan McMullin; 6. The alpha and the omega: reflections on the origin and future of life from the perspective of Christian theology and ethics Celia Deane-Drummond; Part II. Extent of Life: 7. A biologist's guide to the Solar System Lynn Rothschild; 8. The quest for habitable worlds and life beyond the Solar System Carl Pilcher; 9. A historical perspective on the extent and search for life Steven J. Dick; 10. The search for extraterrestrial life: epistemology, ethics, and worldviews Mark Lupisella; 11. The implications of discovering extraterrestrial life: different searches, different issues Margaret S. Race; 12. God, evolution, and astrobiology Cynthia S. W. Crysdale; Part III. Future of Life: 13. Planetary ecosynthesis on Mars: restoration ecology and environmental ethics Christopher P. McKay; 14. The trouble with intrinsic value: an ethical primer for astrobiology Kelly C. Smith; 15. God's preferential option for life: a Christian perspective on astrobiology Richard O. Randolph; 16. Comparing stories about the origin, extent, and future of life: an Asian religious perspective Francisca Cho; Index.

The Role of Extraterrestrial Materials in the Origin of Life

NASA Technical Reports Server (NTRS)

Sandford, Scott A.

2016-01-01

It has been well established for some time now that C-rich organic materials are relatively common in a number of environments in space. This is known through the telescopic detection of these materials using spectroscopy techniques in the infrared and sub-millimeter wavelength ranges and through the identification of organics in extraterrestrial materials. Extraterrestrial materials in which organics have been found include collected meteorites and interplanetary dust particles, and samples returned by NASA spacecraft from comets. These organics are produced by a variety of astrochemical processes. Despite their abiotic origins, these organic materials of are considerable interest to astrobiology for several reasons. First, organic materials of any composition are important as a means of delivering the elements C, H, O, and N to the surfaces of newly formed planets, and these elements are likely critical to the origin and subsequent evolution of life (certainly for life as we know it). In addition, it is clear that at least a portion of the organics found in space are in the form of molecules that play important roles in modern biology - for example, molecules like amino acids, amphiphiles, quinones, etc. Thus, the delivery of extraterrestrial organics to planetary surfaces brings not only bulk C, H, O, and N, but also molecular complexity in forms that are potentially useful for the origin and early evolution of life. This suggests that the production and delivery of cosmic organic compounds may have played key roles in the origin of life on Earth and, by extension, on other planets in the universe.

General order of the origin of life in the Universe

NASA Astrophysics Data System (ADS)

Kompanichenko, V. N.

2007-08-01

The principal succession of transformations of organic matter leading to its transition into the primary living units is theoretically substantiated in the framework of the systemic approach to the origin of life (Kompanichenko, 2004). The succession is conditionally divided into three stages. For 1st stage significant change of conditions in the host aquatic medium constrains an organic prebiotic microsystem to leave the current stable state with the following transition into a new stable state through the unstable critical (bifurcation) point. At the critical point the microsystem acquires the original properties without of which life cannot exist (self-maintaining heterogeneous structure, incessant fluctuations and rearrangement of molecules, exchange with the surroundings by matter and energy, etc.). During 2nd stage its unstable (nonequilibrium) state relatively stabilizes by means of the balanced oscillations around the bifurcation point (there appears the paradoxical state "stabilized instability"). In this way the microsystem keeps the original critical properties and acquires biforked structure. This rare and unusual type of natural systems was called a bistate system. 3rd stage is characterized with the radical turn in the network of chemical reactions (from in Vitro into in Vivo): the free energy contribution begins to prevail over entropy contribution. As a result, constructive transformations proceed faster than destructive ones. Just at this stage the key properties of biological organization appeared: the ability to concentrate free energy and information, ability for intensified counteraction to external influences, expedient behaviour, persistent self-renovating. In accordance with the conception, on the early Earth such successive transformation of organic matter occurred in the changeable conditions of hydrothermal medium. Most of the scientific knowledge that was put in background of the elaborated systemic conception of the origin of life

Conditions on Early Mars Might Have Fostered Rapid and Early Development of Life

NASA Technical Reports Server (NTRS)

Gibson, Everett K.; McKay, David S.; Thomas-Keprta, Kathie L.; Clemett, Simon J.; Wentworth, Susan J.

2007-01-01

The exploration of Mars during the past decades has begun to unveil the history of the planet. The combinations of remote sensing, in situ geochemical compositional measurements and photographic observations from both above and on the surface have shown Mars to have a dynamic and active geologic evolution. Mars geologic evolution clearly had conditions that were suitable for supporting life. For a planet to be able to be habitable, it must have water, carbon sources, energy sources and a dynamic geologic past. Mars meets all of these requirements. The first 600 My of Martian history were ripe for life to develop because of the abundance of (i) Water-carved canyons and oceans or lakes with the early presence of near surface water shown by precipitated carbonates in ALH84001 well-dated at approx.3.9 Gy., (ii) Energy from the original accretional processes, a molten core which generated a strong magnetic field leaving a permanent record in the early crust, early active volcanism continuing throughout Martian history, and, and continuing impact processes, (iii) Carbon and water from possibly extensive volcanic outgassing (i.e. H2O, CO2, CH4, CO, O2, N2, H2S, SO2, etc.) and (iv) some crustal tectonics as revealed by faulting and possible plate movement reflected by the magnetic pattern in the crust. The question arises: "Why would life not evolve from these favorable conditions on early Mars in its first 600 My?" During this period, it seems likely that environmental near-surface conditions on Mars were more favorable to life than at any later time. Standing bodies of water, precipitation and flowing surface water, and possibly abundant hydrothermal energy would all favor the formation of early life. Even if life developed elsewhere (on Earth, Venus, or on other solar systems) and was transported to Mars, the surface conditions were likely very hospitable for that introduced life to multiply and evolve.

Sudden Unexpected Death in Fetal Life Through Early Childhood

PubMed Central

Kinney, Hannah C.; Willinger, Marian

2016-01-01

In March 2015, the Eunice Kennedy Shriver National Institute of Child Health and Human Development held a workshop entitled “Sudden Unexpected Death in Fetal Life Through Early Childhood: New Opportunities.” Its objective was to advance efforts to understand and ultimately prevent sudden deaths in early life, by considering their pathogenesis as a potential continuum with some commonalities in biological origins or pathways. A second objective of this meeting was to highlight current issues surrounding the classification of sudden infant death syndrome (SIDS), and the implications of variations in the use of the term “SIDS” in forensic practice, and pediatric care and research. The proceedings reflected the most current knowledge and understanding of the origins and biology of vulnerability to sudden unexpected death, and its environmental triggers. Participants were encouraged to consider the application of new technologies and “omics” approaches to accelerate research. The major advances in delineating the intrinsic vulnerabilities to sudden death in early life have come from epidemiologic, neural, cardiac, metabolic, genetic, and physiologic research, with some commonalities among cases of unexplained stillbirth, SIDS, and sudden unexplained death in childhood observed. It was emphasized that investigations of sudden unexpected death are inconsistent, varying by jurisdiction, as are the education, certification practices, and experience of death certifiers. In addition, there is no practical consensus on the use of “SIDS” as a determination in cause of death. Major clinical, forensic, and scientific areas are identified for future research. PMID:27230764

Conditions for the emergence of life on the early Earth: summary and reflections

PubMed Central

Jortner, Joshua

2006-01-01

This review attempts to situate the emergence of life on the early Earth within the scientific issues of the operational and mechanistic description of life, the conditions and constraints of prebiotic chemistry, together with bottom-up molecular fabrication and biomolecular nanofabrication and top-down miniaturization approaches to the origin of terrestrial life. PMID:17008225

The Porto Alegre Early Life Nutrition and Health Study.

PubMed

Chaffee, Benjamin Wilk; Vítolo, Márcia Regina; Feldens, Carlos Alberto

2014-12-01

Early childhood caries is a persistent worldwide problem. The etiologic contribution of feeding practices has been less frequently investigated in prospective studies of young children. The Porto Alegre Early Life Nutrition and Health Study has followed a birth cohort of 715 mother-child pairs, recruited from municipal health centers, originally involved in a cluster-randomized controlled trial of healthcare worker training. The birth cohort links prospectively collected socio-demographic, infant feeding, and general and oral health information. To date, oral health data, including caries status and oral health-related quality of life, have been collected for 458 children at the age of 2-3 years. Studies are underway to investigate possible determinants and consequences of oral health among these children.

Constraining the Time Interval for the Origin of Life on Earth.

PubMed

Pearce, Ben K D; Tupper, Andrew S; Pudritz, Ralph E; Higgs, Paul G

2018-03-01

Estimates of the time at which life arose on Earth make use of two types of evidence. First, astrophysical and geophysical studies provide a timescale for the formation of Earth and the Moon, for large impact events on early Earth, and for the cooling of the early magma ocean. From this evidence, we can deduce a habitability boundary, which is the earliest point at which Earth became habitable. Second, biosignatures in geological samples, including microfossils, stromatolites, and chemical isotope ratios, provide evidence for when life was actually present. From these observations we can deduce a biosignature boundary, which is the earliest point at which there is clear evidence that life existed. Studies with molecular phylogenetics and records of the changing level of oxygen in the atmosphere give additional information that helps to determine the biosignature boundary. Here, we review the data from a wide range of disciplines to summarize current information on the timings of these two boundaries. The habitability boundary could be as early as 4.5 Ga, the earliest possible estimate of the time at which Earth had a stable crust and hydrosphere, or as late as 3.9 Ga, the end of the period of heavy meteorite bombardment. The lack of consensus on whether there was a late heavy meteorite bombardment that was significant enough to prevent life is the largest uncertainty in estimating the time of the habitability boundary. The biosignature boundary is more closely constrained. Evidence from carbon isotope ratios and stromatolite fossils both point to a time close to 3.7 Ga. Life must have emerged in the interval between these two boundaries. The time taken for life to appear could, therefore, be within 200 Myr or as long as 800 Myr. Key Words: Origin of life-Astrobiology-Habitability-Biosignatures-Geochemistry-Early Earth. Astrobiology 18, 343-364.

Development of Life on Early Mars

NASA Technical Reports Server (NTRS)

Gibson, Everett K.; McKay, David S.; Thomas-Keprta, Kathie L.; Clemett, Simon J.; Wentworth, Susan J.

2009-01-01

Exploration of Mars has begun to unveil the history of the planet. Combinations of remote sensing, in situ compositional measurements and photographic observations have shown Mars had a dynamic and active geologic evolution. Mars geologic evolution encompassed conditions that were suitable for supporting life. A habitable planet must have water, carbon and energy sources along with a dynamic geologic past. Mars meets all of these requirements. The first 600 My of Martian history were ripe for life to develop because of the abundance of (i) Water- as shown by carved canyons and oceans or lakes with the early presence of near surface water shown by precipitated carbonates in ALH84001, well-dated at 3.9 Gy, (ii) Energy from the original accretional processes, a molten core which generated a strong magnetic field leaving a permanent record in the early crust, active volcanism continuing throughout Martian history, and continuing impact processes, (iii) Carbon, water and a likely thicker atmosphere from extensive volcanic outgassing (i.e. H20, CO2, CH4, CO, O2, N2, H2S, SO2, etc.) and (iv) crustal tectonics as revealed by faulting and possible plate movement reflected by the magnetic pattern in the crust [1]. The question arises: "Why would life not develop from these favorable conditions on Mars in its first 600 My?" During this period, environmental near-surface conditions on Mars were more favorable to life than at any later time. Standing bodies of water, precipitation and flowing surface water, and possibly abundant hydrothermal energy would favor the formation of early life. (Even if life developed elsewhere on Earth, Venus, or on other bodies-it was transported to Mars where surface conditions were suitable for life to evolve). The commonly stated requirement that life would need hundreds of millions of year to get started is only an assumption; we know of no evidence that requires such a long interval for the development of life, if the proper habitable

Origins of Life; A cosmic perspective

NASA Astrophysics Data System (ADS)

Whittet, Douglas

2017-11-01

'Origins of Life: A Cosmic Perspective' presents an overview of the concepts, methods, and theories of astrobiology and origins of life research while presenting a summary of the latest findings. The book provides insight into the environments and processes that gave birth to life on our planet, which naturally informs our assessment of the probability that has arisen (or will arise) elsewhere. In addition, the book encourages readers to go beyond basic concepts, to explore topics in greater depth, and to engage in lively discussions.

Origin of life: LUCA and extracellular membrane vesicles (EMVs)

NASA Astrophysics Data System (ADS)

Gill, S.; Forterre, P.

2016-01-01

Cells from the three domains of life produce extracellular membrane vesicles (EMVs), suggesting that EMV production is an important aspect of cellular physiology. EMVs have been implicated in many aspects of cellular life in all domains, including stress response, toxicity against competing strains, pathogenicity, detoxification and resistance against viral attack. These EMVs represent an important mode of inter-cellular communication by serving as vehicles for transfer of DNA, RNA, proteins and lipids between cells. Here, we review recent progress in the understanding of EMV biology and their various roles. We focus on the role of membrane vesicles in early cellular evolution and how they would have helped shape the nature of the last universal common ancestor. A membrane-protected micro-environment would have been a key to the survival of spontaneous molecular systems and efficient metabolic reactions. Interestingly, the morphology of EMVs is strongly reminiscent of the morphology of some virions. It is thus tempting to make a link between the origin of the first protocell via the formation of vesicles and the origin of viruses.

Estimates of the maximum time required to originate life

NASA Technical Reports Server (NTRS)

Oberbeck, Verne R.; Fogleman, Guy

1989-01-01

Fossils of the oldest microorganisms exist in 3.5 billion year old rocks and there is indirect evidence that life may have existed 3.8 billion years ago (3.8 Ga). Impacts able to destroy life or interrupt prebiotic chemistry may have occurred after 3.5 Ga. If large impactors vaporized the oceans, sterilized the planets, and interfered with the origination of life, life must have originated in the time interval between these impacts which increased with geologic time. Therefore, the maximum time required for the origination of life is the time that occurred between sterilizing impacts just before 3.8 Ga or 3.5 Ga, depending upon when life first appeared on earth. If life first originated 3.5 Ga, and impacts with kinetic energies between 2 x 10 the the 34th and 2 x 10 to the 35th were able to vaporize the oceans, using the most probable impact flux, it is found that the maximum time required to originate life would have been 67 to 133 million years (My). If life originated 3.8 Ga, the maximum time to originate life was 2.5 to 11 My. Using a more conservative estimate for the flux of impacting objects before 3.8 Ga, a maximum time of 25 My was found for the same range of impactor kinetic energies. The impact model suggests that it is possible that life may have originated more than once.

Chance, necessity and the origins of life: a physical sciences perspective.

PubMed

Hazen, Robert M

2017-12-28

Earth's 4.5-billion-year history has witnessed a complex sequence of high-probability chemical and physical processes, as well as 'frozen accidents'. Most models of life's origins similarly invoke a sequence of chemical reactions and molecular self-assemblies in which both necessity and chance play important roles. Recent research adds two important insights into this discussion. First, in the context of chemical reactions, chance versus necessity is an inherently false dichotomy-a range of probabilities exists for many natural events. Second, given the combinatorial richness of early Earth's chemical and physical environments, events in molecular evolution that are unlikely at limited laboratory scales of space and time may, nevertheless, be inevitable on an Earth-like planet at time scales of a billion years.This article is part of the themed issue 'Reconceptualizing the origins of life'. © 2017 The Author(s).

Chance, necessity and the origins of life: a physical sciences perspective

NASA Astrophysics Data System (ADS)

Hazen, Robert M.

2017-11-01

Earth's 4.5-billion-year history has witnessed a complex sequence of high-probability chemical and physical processes, as well as `frozen accidents'. Most models of life's origins similarly invoke a sequence of chemical reactions and molecular self-assemblies in which both necessity and chance play important roles. Recent research adds two important insights into this discussion. First, in the context of chemical reactions, chance versus necessity is an inherently false dichotomy-a range of probabilities exists for many natural events. Second, given the combinatorial richness of early Earth's chemical and physical environments, events in molecular evolution that are unlikely at limited laboratory scales of space and time may, nevertheless, be inevitable on an Earth-like planet at time scales of a billion years. This article is part of the themed issue 'Reconceptualizing the origins of life'.

The Martian subsurface as a potential window into the origin of life

NASA Astrophysics Data System (ADS)

Michalski, Joseph R.; Onstott, Tullis C.; Mojzsis, Stephen J.; Mustard, John; Chan, Queenie H. S.; Niles, Paul B.; Johnson, Sarah Stewart

2018-01-01

Few traces of Earth's geologic record are preserved from the time of life's emergence, over 3,800 million years ago. Consequently, what little we understand about abiogenesis — the origin of life on Earth — is based primarily on laboratory experiments and theory. The best geological lens for understanding early Earth might actually come from Mars, a planet with a crust that's overall far more ancient than our own. On Earth, surface sedimentary environments are thought to best preserve evidence of ancient life, but this is mostly because our planet has been dominated by high photosynthetic biomass production at the surface for the last 2,500 million years or more. By the time oxygenic photosynthesis evolved on Earth, Mars had been a hyperarid, frozen desert with a surface bombarded by high-energy solar and cosmic radiation for more than a billion years, and as a result, photosynthetic surface life may never have occurred on Mars. Therefore, one must question whether searching for evidence of life in Martian surface sediments is the best strategy. This Perspective explores the possibility that the abundant hydrothermal environments on Mars might provide more valuable insights into life's origins.

A Strategy for Origins of Life Research.

PubMed

Scharf, Caleb; Virgo, Nathaniel; Cleaves, H James; Aono, Masashi; Aubert-Kato, Nathanael; Aydinoglu, Arsev; Barahona, Ana; Barge, Laura M; Benner, Steven A; Biehl, Martin; Brasser, Ramon; Butch, Christopher J; Chandru, Kuhan; Cronin, Leroy; Danielache, Sebastian; Fischer, Jakob; Hernlund, John; Hut, Piet; Ikegami, Takashi; Kimura, Jun; Kobayashi, Kensei; Mariscal, Carlos; McGlynn, Shawn; Menard, Brice; Packard, Norman; Pascal, Robert; Pereto, Juli; Rajamani, Sudha; Sinapayen, Lana; Smith, Eric; Switzer, Christopher; Takai, Ken; Tian, Feng; Ueno, Yuichiro; Voytek, Mary; Witkowski, Olaf; Yabuta, Hikaru

2015-12-01

Contents 1. Introduction 1.1. A workshop and this document 1.2. Framing origins of life science 1.2.1. What do we mean by the origins of life (OoL)? 1.2.2. Defining life 1.2.3. How should we characterize approaches to OoL science? 1.2.4. One path to life or many? 2. A Strategy for Origins of Life Research 2.1. Outcomes-key questions and investigations 2.1.1. Domain 1: Theory 2.1.2. Domain 2: Practice 2.1.3. Domain 3: Process 2.1.4. Domain 4: Future studies 2.2. EON Roadmap 2.3. Relationship to NASA Astrobiology Roadmap and Strategy documents and the European AstRoMap   Appendix I   Appendix II   Supplementary Materials  References.

Chemical evolution and the origin of life: cumulative keyword subject index 1970-1986

NASA Technical Reports Server (NTRS)

Roy, A. C.; Powers, J. V.; Rummel, J. D. (Principal Investigator)

1990-01-01

This cumulative subject index encompasses the subject indexes of the bibliographies on Chemical Evolution and the Origin of Life that were first published in 1970 and have continued through publication of the 1986 bibliography supplement. Early bibliographies focused on experimental and theoretical material dealing directly with the concepts of chemical evolution and the origin of life, excluding the broader areas of exobiology, biological evolution, and geochemistry. In recent years, these broader subject areas have also been incorporated as they appear in literature searches relating to chemical evolution and the origin of life, although direct attempts have not been made to compile all of the citations in these broad areas. The keyword subject indexes have also undergone an analogous change in scope. Compilers of earlier bibliographies used the most specific term available in producing the subject index. Compilers of recent bibliographies have used a number of broad terms relating to the overall subject content of each citation and specific terms where appropriate. The subject indexes of these 17 bibliographies have, in general, been cumulatively compiled exactly as they originally appeared. However, some changes have been made in an attempt to correct errors, combine terms, and provide more meaningful terms.

A Radical Pathway for Organic Phosphorylation during Schreibersite Corrosion with Implications for the Origin of Life

NASA Technical Reports Server (NTRS)

Pasek, Matthew A.; Dworkin, Jason P.; Lauretta, Dante S.

2007-01-01

Phosphorylated compounds (e.g. DNA, RNA, phospholipids, and many coenzymes) are critical to biochemistry. Thus, their origin is of prime interest to origin of life studies. The corrosion of the meteoritic mineral schreibersite ((Fe,Ni)3P) may have significantly contributed to the origin of phosphorylated biomolecules. Corrosion of synthetic schreibersite in a variety of solutions was analyzed by nuclear magnetic resonance spectroscopy, mass spectrometry, and electron paramagnetic resonance spectroscopy. These methods suggest a radical reaction pathway for the corrosion of schreibersite to form phosphite radicals (raised dot PO3 sup 2-)) aqueous solution. These radicals can form activated polyphosphates and can phosphorylate organic compounds such as acetate (3% yield). Phosphonates (O3P-C) are found in the organic P inventory of the carbonaceous meteorite Murchison. While phosphonates are rare in biochemistry, the ubiquity of corroding iron meteorites on the early Earth could have provided an accessible source of organophosphorous for the origin of life allowing the invention of the organophosphates in modern biology as a product of early evolution.

A Strategy for Origins of Life Research

PubMed Central

Scharf, Caleb; Virgo, Nathaniel; Aono, Masashi; Aubert-Kato, Nathanael; Aydinoglu, Arsev; Barahona, Ana; Barge, Laura M.; Benner, Steven A.; Biehl, Martin; Brasser, Ramon; Butch, Christopher J.; Chandru, Kuhan; Cronin, Leroy; Danielache, Sebastian; Fischer, Jakob; Hernlund, John; Hut, Piet; Ikegami, Takashi; Kimura, Jun; Kobayashi, Kensei; Mariscal, Carlos; McGlynn, Shawn; Menard, Brice; Packard, Norman; Pascal, Robert; Pereto, Juli; Rajamani, Sudha; Sinapayen, Lana; Smith, Eric; Switzer, Christopher; Takai, Ken; Tian, Feng; Ueno, Yuichiro; Voytek, Mary; Witkowski, Olaf; Yabuta, Hikaru

2015-01-01

Contents 1. Introduction 1.1. A workshop and this document 1.2. Framing origins of life science 1.2.1. What do we mean by the origins of life (OoL)? 1.2.2. Defining life 1.2.3. How should we characterize approaches to OoL science? 1.2.4. One path to life or many? 2. A Strategy for Origins of Life Research 2.1. Outcomes—key questions and investigations 2.1.1. Domain 1: Theory 2.1.2. Domain 2: Practice 2.1.3. Domain 3: Process 2.1.4. Domain 4: Future studies 2.2. EON Roadmap 2.3. Relationship to NASA Astrobiology Roadmap and Strategy documents and the European AstRoMap  Appendix I  Appendix II  Supplementary Materials  References PMID:26684503

Early Mars: A Warm Wet Niche for Life

NASA Technical Reports Server (NTRS)

Gibson, Everett K.; McKay, David S.; Thomas-Keprta, Kathie L.; Clemett, Simon J.

2010-01-01

Exploration of Mars has begun to unveil the history of the planet. Combinations of remote sensing, in situ compositional measurements and photographic observations have shown Mars had a dynamic and active geologic evolution. Mars geologic evolution had conditions that were suitable for supporting life. A habitable planet must have water, carbon and energy sources along with a dynamic geologic past. Mars meets all of these requirements. The first 600 Ma of Martian history were ripe for life to develop because of the abundance of: (i) Water-as shown by carved canyons and oceans or lakes with the early presence of near surface water shown by precipitated carbonates in ALH84001, well-dated at approx.3.9 Ga, (ii) Energy from the original accretional processes, a molten core which generated a strong magnetic field leaving a permanent record in the early crust, active volcanism continuing throughout Martian history, and continuing impact processes, (iii) Carbon, water and a likely thicker atmosphere from extensive volcanic outgassing (i.e. H2O, CO2, CH4, CO, O2, N2, H2S, SO2, etc.) and (iv) crustal tectonics as revealed by faulting and possible plate movement reflected by the magnetic patterns in the crust [1]. The question arises: "Why would life not develop from these favorable conditions on Mars in its first 600 Ma?" During this period, environmental near-surface conditions on Mars were more favorable to life than at any later time. Standing bodies of water, precipitation and flowing surface water, and possibly abundant hydrothermal energy would favor the formation of early life. (Even if life developed elsewhere on Earth, Venus, or on other bodies-it was transported to Mars where surface conditions were suitable for life to evolve)

Chirality and the origin of life

NASA Astrophysics Data System (ADS)

Bailey, Jeremy

2000-06-01

The homochirality of biological molecules (the use of only left handed amino acids and only right handed sugars) has long been known to be an important characteristic of life. Current ideas on the origin of life do not explain the origin of homochirality, yet the widely accepted 'RNA world' model cannot work without it. The recent discoveries of chiral asymmetry in the Murchison meteorite, and of strong circular polarization in star formation regions lead to a plausible model for an extraterrestrial origin of homochirality. UV light circularly polarized by scattering can introduce chiral asymmetry into interstellar molecules. These molecules can then be delivered to the surface of the Earth by comets and meteorites during the heavy bombardment phase in the first few hundred million years of the solar system. This model suggests that the probability of finding life on planets of other stars may depend on the polarization environment in the star formation region from which they came. Our solar system may well have been particularly favoured in having the right conditions for the emergence of life.

Planetary Systems and the Origins of Life

NASA Astrophysics Data System (ADS)

Pudritz, Ralph; Higgs, Paul; Stone, Jonathon

2013-01-01

Preface; Part I. Planetary Systems and the Origins of Life: 1. Observations of extrasolar planetary systems Shay Zucker; 2. The atmospheres of extrasolar planets L. Jeremy Richardson and Sara Seager; 3. Terrestrial planet formation Edward Thommes; 4. Protoplanetary disks, amino acids and the genetic code Paul Higgs and Ralph Pudritz; 5. Emergent phenomena in biology: the origin of cellular life David Deamer; Part II. Life on Earth: 6. Extremophiles: defining the envelope for the search for life in the Universe Lynn Rothschild; 7. Hyperthermophilic life on Earth - and on Mars? Karl Stetter; 8. Phylogenomics: how far back in the past can we go? Henner Brinkmann, Denis Baurain and Hervé Philippe; 9. Horizontal gene transfer, gene histories and the root of the tree of life Olga Zhaxybayeva and J. Peter Gogarten; 10. Evolutionary innovation versus ecological incumbency Adolf Seilacher; 11. Gradual origins for the Metazoans Alexandra Pontefract and Jonathan Stone; Part III. Life in the Solar System?: 12. The search for life on Mars Chris McKay; 13. Life in the dark dune spots of Mars: a testable hypothesis Eörs Szathmary, Tibor Ganti, Tamas Pocs, Andras Horvath, Akos Kereszturi, Szaniszlo Berzci and Andras Sik; 14. Titan: a new astrobiological vision from the Cassini-Huygens data François Raulin; 15. Europa, the Ocean Moon: tides, permeable ice, and life Richard Greenberg; Index.

Evidence from Meteorites for Multiple Possible Amino Acid Alphabets for the Origins of Life

NASA Technical Reports Server (NTRS)

Burton, A. S.; Elsila, J. E.; Callahan, M. P.; Glavin, D. P.; Dworkin, J. P.

2015-01-01

A key question for the origins of life is understanding which amino acids made up the first proteins synthesized during the origins of life. The canonical set of 20 - 22 amino acids used in proteins are all alpha-amino, alpha-hydrogen isomers that, nevertheless, show considerable variability in properties including size, hydrophobicity, and ionizability. Abiotic amino acid synthesis experiments such as Miller-Urey spark discharge reactions produce a set of up to 23 amino acids, depending on starting materials and reaction conditions, with significant abundances of both alpha- and non-alpha-amino acid isomers. These two sets of amino acids do not completely overlap; of the 23 spark discharge amino acids, only 11 are used in modern proteins. Furthermore, because our understanding of conditions on the early Earth are limited, it is unclear which set(s) of conditions employed in spark discharge or hydrothermal reactions are correct, leaving us with significant uncertainty about the amino acid alphabet available for the origins of life on Earth. Meteorites, the surviving remnants of asteroids and comets that fall to the Earth, offer the potential to study authentic samples of naturally-occurring abiotic chemistry, and thus can provide an alternative approach to constraining the amino acid library during the origins of life.

A Hot Spring Origin of Life and Early Adaptive Pathway from Woese Progenotes to Marine Stromatolites

NASA Astrophysics Data System (ADS)

Norkus, R.; Damer, B. F.; Deamer, D. W.

2017-07-01

An origin of life on land is visualized as: organic compounds accumulating in hydrothermal pools, wet-dry cycling of protocells encapsulating synthesized polymers, arising of a Woese progenote and its evolution into living microbial communities.

Age Validation in the Long Life Family Study Through a Linkage to Early-Life Census Records

PubMed Central

2013-01-01

Objectives. Studies of health and longevity require accurate age reporting. Age misreporting among older adults in the United States is common. Methods. Participants in the Long Life Family Study (LLFS) were matched to early-life census records. Age recorded in the census was used to evaluate age reporting in the LLFS. The study population was 99% non-Hispanic white. Results. About 88% of the participants were matched to 1910, 1920, or 1930 U.S. censuses. Match success depended on the participant’s education, place of birth, and the number of censuses available to be searched. Age at the time of the interview based on the reported date of birth and early-life census age were consistent for about 89% of the participants, and age consistency within 1 year was found for about 99% of the participants. Discussion. It is possible to match a high fraction of older study participants to their early-life census records when detailed information is available on participants’ family of origin. Such record linkage can provide an important source of information for evaluating age reporting among the oldest old participants. Our results are consistent with recent studies suggesting that age reporting among older whites in the United States appears to be quite good. PMID:23704206

The violent environment of the origin of life - Progress and uncertainties

NASA Technical Reports Server (NTRS)

Chyba, Christopher F.

1993-01-01

Dating of terrestrial fossils and returned lunar samples reveals that the origin of life on Earth occurred not in a quiescent, peaceful environment, but rather in a violent, impact-ridden one. This realization has important consequences. On the one hand, sufficiently large and fast impactors can erode planetary atmospheres, and the very largest of these may have sterilized the surface of the Earth. In this regard, deep-sea hydrothermal vents become especially interesting for the history of early life, as they provide an environment protected against all but the greatest impact devastation. At the same time, impactors would have been delivering key biogenic elements (such as carbon and nitrogen) to Earth's surface, and (with much greater difficulty) intact organic molecules as well. Estimates of the various sources of prebiotic organics suggest that the heavy bombardment either produced or delivered quantities of organics comparable to those produced by other energy sources. However, substantial uncertainties exist. After reviewing the current understanding of the role of the heavy bombardment in the origins of life, a number of remaining key uncertainties are considered, and attempts are made to both quantify their magnitude and point to means of resolving them.

Predicting Later-Life Outcomes of Early-Life Exposures

EPA Science Inventory

Background: In utero exposure of the fetus to a stressor can lead to disease in later life. Epigenetic mechanisms are likely mediators of later-life expression of early-life events.Objectives: We examined the current state of understanding of later-life diseases resulting from ea...

Chemical Evolution and the Origin of Life: Bibliography 1975

NASA Technical Reports Server (NTRS)

West, Martha W. (Compiler); Koch, Rowena A. (Compiler); Chang, Sherwood (Compiler)

1977-01-01

This bibliography is the sixth annual supplement to the comprehensive bibliography on the same subject which was published in Space Life Sci.We would like to draw attention to a recently published cumulative bibliography on this same subject: Biochemical Origin of Life: Chemistry and Life. Soil and Water and Its Relationship to Origin of Life. MR - Studies of Prebiotic Polypeptides. Energy, Matter, and Life. Prospects for the Future Orientation of Scientific Research. Photochemical Formation of Self Sustaining Coacervates. Photochemical Formation of Self-Sustaining Coacervates. Comparative Study of Abiogenesis of Cysteine and Other Amino Acids Catalyzed by Various Metal Ions. Protein Structure and the Molecular Evolution of Biological Energy Conversion. Origin of Life. Clues from Relations Between Chemical Compositions of Living Organisms and Natural Environments. Shock Synthesis of Amino Acids II.', Origins of Life 6(1-2). Dynamics of the Chemical Evolution of Earth's Primitive Atmosphere. The Mechanisms of Amino Acids Synthesis by High Temperature Shock-Waves. Theory of Chemical Evolution. Physical Foundations of Probability of Biogenesis.

Extraterrestrial Organic Chemistry: From the Interstellar Medium to the Origins of Life

NASA Technical Reports Server (NTRS)

Pohorille, Andrew; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

Extraterrestrially delivered organics in the origin of cellular life. Various processes leading to the emergence of cellular life from organics delivered from space to earth or other planetary bodies in the solar system will be reviewed. The focus will be on: (1) self-assembly of amphiphilic material to vesicles and other structures, such as micelles and multilayers, and its role in creating environments suitable for chemical catalysis, (2) a possible role of extraterrestrial delivery of organics in the formation of the simplest bioenergetics (3) mechanisms leading from amino acids or their precursors to simple peptides and, subsequently, to the evolution of metabolism. These issues will be discussed from two opposite points of view: (1) Which molecules could have been particularly useful in the protobiological evolution; this may provide focus for searching for these molecules in interstellar media. (2) Assuming that a considerable part of the inventory of organic matter on the early earth was delivered extraterrestrially, what does relative abundance of different organics in space tell us about the scenario leading to the origin of life.

"Origin," "creation," and "origin of life" some conceptual considerations.

PubMed

Charpa, Ulrich

2012-01-01

This paper opens by drawing attention to the fact that there is some conceptual confusion with regard to "origin" and "creation." This has its historical roots in the beginnings of modern science and undoubtedly affects our positioning towards the evolutionism/creationism-debate. This article argues that there are relevant ontological, epistemological, thematic, methodological, and logical differences between "origin" and "creation." As a result, the analysis suggests keeping the usage of both concepts strictly quite separate. Creation is not simply another word for origin nor does it stand for an (from a rigid scientific point of view) awkward example of an origin. Irrespective of the apparent similarities as explanatory factors, origin and creation belong to fundamentally different types of concepts. Consequently, "origin of life" and those scientific projects connected to it present themselves as something distinct that neither competes nor meshes with thinking about creation.

Early life risk factors and their cumulative effects as predictors of overweight in Spanish children.

PubMed

Iguacel, Isabel; Escartín, Laura; Fernández-Alvira, Juan M; Iglesia, Iris; Labayen, Idoia; Moreno, Luis A; Samper, María Pilar; Rodríguez, Gerardo

2018-05-01

To explore early life risk factors of overweight/obesity at age 6 years and their cumulative effects on overweight/obesity at ages 2, 4 and 6 years. Altogether 1031 Spanish children were evaluated at birth and during a 6-year follow-up. Early life risk factors included: parental overweight/obesity, parental origin/ethnicity, maternal smoking during pregnancy, gestational weight gain, gestational age, birth weight, caesarean section, breastfeeding practices and rapid infant weight gain collected via hospital records. Cumulative effects were assessed by adding up those early risk factors that significantly increased the risk of overweight/obesity. We conducted binary logistic regression models. Rapid infant weight gain (OR 2.29, 99% CI 1.54-3.42), maternal overweight/obesity (OR 1.93, 99% CI 1.27-2.92), paternal overweight/obesity (OR 2.17, 99% CI 1.44-3.28), Latin American/Roma origin (OR 3.20, 99% CI 1.60-6.39) and smoking during pregnancy (OR 1.61, 99% CI 1.01-2.59) remained significant after adjusting for confounders. A higher number of early life risk factors accumulated was associated with overweight/obesity at age 6 years but not at age 2 and 4 years. Rapid infant weight gain, parental overweight/obesity, maternal smoking and origin/ethnicity predict childhood overweight/obesity and present cumulative effects. Monitoring children with rapid weight gain and supporting a healthy parental weight are important for childhood obesity prevention.

Early-Life Toxic Insults and Onset of Sporadic Neurodegenerative Diseases-an Overview of Experimental Studies.

PubMed

Tartaglione, Anna Maria; Venerosi, Aldina; Calamandrei, Gemma

2016-01-01

The developmental origin of health and disease hypothesis states that adverse fetal and early childhood exposures can predispose to obesity, cardiovascular, and neurodegenerative diseases (NDDs) in adult life. Early exposure to environmental chemicals interferes with developmental programming and induces subclinical alterations that may hesitate in pathophysiology and behavioral deficits at a later life stage. The mechanisms by which perinatal insults lead to altered programming and to disease later in life are still undefined. The long latency between exposure and onset of disease, the difficulty of reconstructing early exposures, and the wealth of factors which the individual is exposed to during the life course make extremely difficult to prove the developmental origin of NDDs in clinical and epidemiological studies. An overview of animal studies assessing the long-term effects of perinatal exposure to different chemicals (heavy metals and pesticides) supports the link between exposure and hallmarks of neurodegeneration at the adult stage. Furthermore, models of maternal immune activation show that brain inflammation in early life may enhance adult vulnerability to environmental toxins, thus supporting the multiple hit hypothesis for NDDs' etiology. The study of prospective animal cohorts may help to unraveling the complex pathophysiology of sporadic NDDs. In vivo models could be a powerful tool to clarify the mechanisms through which different kinds of insults predispose to cell loss in the adult age, to establish a cause-effect relationship between "omic" signatures and disease/dysfunction later in life, and to identify peripheral biomarkers of exposure, effects, and susceptibility, for translation to prospective epidemiological studies.

Cumulative early life adversity predicts longevity in wild baboons

PubMed Central

Tung, Jenny; Archie, Elizabeth A.; Altmann, Jeanne; Alberts, Susan C.

2016-01-01

In humans and other animals, harsh circumstances in early life predict morbidity and mortality in adulthood. Multiple adverse conditions are thought to be especially toxic, but this hypothesis has rarely been tested in a prospective, longitudinal framework, especially in long-lived mammals. Here we use prospective data on 196 wild female baboons to show that cumulative early adversity predicts natural adult lifespan. Females who experience ≥3 sources of early adversity die a median of 10 years earlier than females who experience ≤1 adverse circumstances (median lifespan is 18.5 years). Females who experience the most adversity are also socially isolated in adulthood, suggesting that social processes partially explain the link between early adversity and adult survival. Our results provide powerful evidence for the developmental origins of health and disease and indicate that close ties between early adversity and survival arise even in the absence of health habit and health care-related explanations. PMID:27091302

Origins of Life Research: a Bibliometric Approach

NASA Astrophysics Data System (ADS)

Aydinoglu, Arsev Umur; Taşkın, Zehra

2018-03-01

This study explores the collaborative nature and interdisciplinarity of the origin(s) of life (OoL) research community. Although OoL research is one of the oldest topics in philosophy, religion, and science; to date there has been no review of the field utilizing bibliometric measures. A dataset of 5647 publications that are tagged as OoL, astrobiology, exobiology, and prebiotic chemistry is analyzed. The most prolific authors (Raulin, Ehrenfreund, McKay, Cleaves, Cockell, Lazcano, etc.), most cited scholars and their articles (Miller 1953, Gilbert 1986, Chyba & Sagan 1992, Wolchtershauser 1988, etc.), and popular journals ( Origins of Life and Evolution of Biospheres and Astrobiology) for OoL research are identified. Moreover, interdisciplinary research conducted through research networks, institutions (NASA, Caltech, University of Arizona, University of Washington, CNRS, etc.), and keywords & concepts (astrobiology, life, Mars, amino acid, prebiotic chemistry, evolution, RNA) are explored.

Early Origins of Child Obesity: Bridging Disciplines and Phases of Development - September 30–October 1, 2010

PubMed Central

Christoffel, Katherine Kaufer; Wang, Xiaobin; Binns, Helen J.

2012-01-01

This report summarizes a conference: “Early Origins of Child Obesity: Bridging Disciplines and Phases of Development”, held in Chicago on September 30–October 1, 2010. The conference was funded in part by the National Institutes of Health and the Williams Heart Foundation, to achieve the conference objective: forging a next-step research agenda related to the early origins of childhood obesity. This research agenda was to include working with an array of factors (from genetic determinants to societal ones) along a continuum from prenatal life to age 7, with an emphasis on how the developing child deals with the challenges presented by his/her environment (prenatal, parental, nutritional, etc.). The conference offered a unique opportunity to facilitate communication and planning of future work among a variety of researchers whose work separately addresses different periods in early life. Over the span of two days, speakers addressed existing, critical research topics within each of the most-studied age ranges. On the final day, workshops fostered the discussion needed to identify the highest priority research topics related to linking varied early factor domains. These are presented for use in planning future research and research funding. PMID:23443002

Symbiosis in cell evolution: Life and its environment on the early earth

NASA Technical Reports Server (NTRS)

Margulis, L.

1981-01-01

The book treats cell evolution from the viewpoint of the serial endosymbiosis theory of the origin of organelles. Following a brief outline of the symbiotic theory, which holds that eukaryotes evolved by the association of free-living bacteria with a host prokaryote, the diversity of life is considered, and five kingdoms of organisms are distinguished: the prokaryotic Monera and the eukaryotic Protoctista, Animalia, Fungi and Plantae. Symbiotic and traditional direct filiation theories of cell evolution are compared. Recent observations of cell structure and biochemistry are reviewed in relation to early cell evolution, with attention given to the geological context for the origin of eukaryotic cells, the origin of major bacterial anaerobic pathways, the relationship between aerobic metabolism and atmospheric oxygen, criteria for distinguishing symbiotic organelles from those that originated by differentiation, and the major classes of eukaryotic organelles: mitochondria, cilia, microtubules, the mitotic and meiotic apparatuses, and pastids. Cell evolution during the Phanerozoic is also discussed with emphasis on the effects of life on the biosphere

The Origin(s) of Whales

NASA Astrophysics Data System (ADS)

Uhen, Mark D.

2010-05-01

Whales are first found in the fossil record approximately 52.5 million years ago (Mya) during the early Eocene in Indo-Pakistan. Our knowledge of early and middle Eocene whales has increased dramatically during the past three decades to the point where hypotheses of whale origins can be supported with a great deal of evidence from paleontology, anatomy, stratigraphy, and molecular biology. Fossils also provide preserved evidence of behavior and habitats, allowing the reconstruction of the modes of life of these semiaquatic animals during their transition from land to sea. Modern whales originated from ancient whales at or near the Eocene/Oligocene boundary, approximately 33.7 Mya. During the Oligocene, ancient whales coexisted with early baleen whales and early toothed whales. By the end of the Miocene, most modern families had originated, and most archaic forms had gone extinct. Whale diversity peaked in the late middle Miocene and fell thereafter toward the Recent, yielding our depauperate modern whale fauna.

Origin of life. The role of experiments, basic beliefs, and social authorities in the controversies about the spontaneous generation of life and the subsequent debates about synthesizing life in the laboratory.

PubMed

Deichmann, Ute

2012-01-01

For centuries the question of the origin of life had focused on the question of the spontaneous generation of life, at least primitive forms of life, from inanimate matter, an idea that had been promoted most prominently by Aristotle. The widespread belief in spontaneous generation, which had been adopted by the Church, too, was finally abandoned at the beginning of the twentieth century, when the question of the origin of life became related to that of the artificial generation of life in the laboratory. This paper examines the role of social authorities, researchers' basic beliefs, crucial experiments, and scientific advance in the controversies about spontaneous generation from the seventeenth to the nineteenth centuries and analyzes the subsequent debates about the synthesis of artificial life in the changing scientific contexts of the nineteenth and early-twentieth centuries. It shows that despite the importance of social authorities, basic beliefs, and crucial experiments scientific advances, especially those in microbiology, were the single most important factor in the stepwise abandoning of the doctrine of spontaneous generation. Research on the origin of life and the artificial synthesis of life became scientifically addressed only when it got rid of the idea of constant smooth transitions between inanimate matter and life and explored possible chemical and physical mechanisms of the specificity of basic molecules and processes of life.

Toward Understanding How Early-Life Stress Reprograms Cognitive and Emotional Brain Networks.

PubMed

Chen, Yuncai; Baram, Tallie Z

2016-01-01

Vulnerability to emotional disorders including depression derives from interactions between genes and environment, especially during sensitive developmental periods. Adverse early-life experiences provoke the release and modify the expression of several stress mediators and neurotransmitters within specific brain regions. The interaction of these mediators with developing neurons and neuronal networks may lead to long-lasting structural and functional alterations associated with cognitive and emotional consequences. Although a vast body of work has linked quantitative and qualitative aspects of stress to adolescent and adult outcomes, a number of questions are unclear. What distinguishes 'normal' from pathologic or toxic stress? How are the effects of stress transformed into structural and functional changes in individual neurons and neuronal networks? Which ones are affected? We review these questions in the context of established and emerging studies. We introduce a novel concept regarding the origin of toxic early-life stress, stating that it may derive from specific patterns of environmental signals, especially those derived from the mother or caretaker. Fragmented and unpredictable patterns of maternal care behaviors induce a profound chronic stress. The aberrant patterns and rhythms of early-life sensory input might also directly and adversely influence the maturation of cognitive and emotional brain circuits, in analogy to visual and auditory brain systems. Thus, unpredictable, stress-provoking early-life experiences may influence adolescent cognitive and emotional outcomes by disrupting the maturation of the underlying brain networks. Comprehensive approaches and multiple levels of analysis are required to probe the protean consequences of early-life adversity on the developing brain. These involve integrated human and animal-model studies, and approaches ranging from in vivo imaging to novel neuroanatomical, molecular, epigenomic, and computational

Comets: Cosmic connections with carbonaceous meteorites, interstellar molecules and the origin of life

NASA Technical Reports Server (NTRS)

Chang, S.

1979-01-01

The ions, radicals, and molecules observed in comets may be derived intact or by partial decomposition from parent compounds of the sort found either in the interstellar medium or in carbonaceous meteorites. The early loss of highly reducing primitive atmosphere and its replacement by a secondary atmosphere dominated by H2O, CO2, and N2, as depicted in current models of the earth's evolution, pose a dilemma for the origin of life: the synthesis of organic compounds necessary for life from components of the secondary atmosphere appears to be difficult, and plausible mechanisms have not been evaluated. Both comets and carbonaceous meteorites are implicated as sources for the earth's atmophilic and organogenic elements. A mass balance argument involving the estimated ratios of hydrogen to carbon in carbonaceous meteorites, comets, and the crust and upper mantle suggests that comets supplied the earth with a large fraction of its volatiles. The probability that comets contributed significantly to the earth's volatile inventory suggests a chemical evolutionary link between comets, prebiotic organic synthesis, and the origin of life.

Sunlight-initiated chemistry of aqueous pyruvic acid: building complexity in the origin of life.

PubMed

Griffith, Elizabeth C; Shoemaker, Richard K; Vaida, Veronica

2013-10-01

Coupling chemical reactions to an energy source is a necessary step in the origin of life. Here, we utilize UV photons provided by a simulated sun to activate aqueous pyruvic acid and subsequently prompt chemical reactions mimicking some of the functions of modern metabolism. Pyruvic acid is interesting in a prebiotic context due to its prevalence in modern metabolism and its abiotic availability on early Earth. Here, pyruvic acid (CH3COCOOH, a C3 molecule) photochemically reacts to produce more complex molecules containing four or more carbon atoms. Acetoin (CH3CHOHCOCH3), a C4 molecule and a modern bacterial metabolite, is produced in this chemistry as well as lactic acid (CH3CHOHCOOH), a molecule which, when coupled with other abiotic chemical reaction pathways, can provide a regeneration pathway for pyruvic acid. This chemistry is discussed in the context of plausible environments on early Earth such as near the ocean surface and atmospheric aerosol particles. These environments allow for combination and exchange of reactants and products of other reaction environments (such as shallow hydrothermal vents). The result could be a contribution to the steady increase in chemical complexity requisite in the origin of life.

Early-life disruption of amphibian microbiota decreases later-life resistance to parasites.

PubMed

Knutie, Sarah A; Wilkinson, Christina L; Kohl, Kevin D; Rohr, Jason R

2017-07-20

Changes in the early-life microbiota of hosts might affect infectious disease risk throughout life, if such disruptions during formative times alter immune system development. Here, we test whether an early-life disruption of host-associated microbiota affects later-life resistance to infections by manipulating the microbiota of tadpoles and challenging them with parasitic gut worms as adults. We find that tadpole bacterial diversity is negatively correlated with parasite establishment in adult frogs: adult frogs that had reduced bacterial diversity as tadpoles have three times more worms than adults without their microbiota manipulated as tadpoles. In contrast, adult bacterial diversity during parasite exposure is not correlated with parasite establishment in adult frogs. Thus, in this experimental setup, an early-life disruption of the microbiota has lasting reductions on host resistance to infections, which is possibly mediated by its effects on immune system development. Our results support the idea that preventing early-life disruption of host-associated microbiota might confer protection against diseases later in life.Early-life microbiota alterations can affect infection susceptibility later in life, in animal models. Here, Knutie et al. show that manipulating the microbiota of tadpoles leads to increased susceptibility to parasitic infection in adult frogs, in the absence of substantial changes in the adults' microbiota.

Exogenous determinants of early-life conditions, and mortality later in life.

PubMed

van den Berg, Gerard J; Doblhammer, Gabriele; Christensen, Kaare

2009-05-01

We analyze causal effects of conditions early in life on the individual mortality rate later in life. Conditions early in life are captured by transitory features of the macro-environment around birth, notably the state of the business cycle around birth, but also food price deviations, weather indicators, and demographic indicators. We argue that these features can only affect high-age mortality by way of the individual early-life conditions. Moreover, they are exogenous from the individual point of view, which is a methodological advantage compared to the use of unique characteristics of the newborn individual or his or her family or household as early-life indicators. We collected national annual time-series data on the above-mentioned indicators, and we combine these to the individual data records from the Danish Twin Registry covering births in 1873-1906. The empirical analyses (mostly based on the estimation of duration models) indicate a significant negative causal effect of economic conditions early in life on individual mortality rates at higher ages. If the national economic performance in the year of birth exceeds its trend value (i.e., if the business cycle is favorable) then the mortality rate later in life is lower. The implied effect on the median lifetime of those who survive until age 35 is about 10 months. A systematic empirical exploration of all macro-indicators reveals that economic conditions in the first years after birth also affect mortality rates later in life.

The Origin and Early Evolution of Membrane Proteins

NASA Technical Reports Server (NTRS)

Pohorille, Andrew; Schweighofter, Karl; Wilson, Michael A.

2006-01-01

The origin and early evolution of membrane proteins, and in particular ion channels, are considered from the point of view that the transmembrane segments of membrane proteins are structurally quite simple and do not require specific sequences to fold. We argue that the transport of solute species, especially ions, required an early evolution of efficient transport mechanisms, and that the emergence of simple ion channels was protobiologically plausible. We also argue that, despite their simple structure, such channels could possess properties that, at the first sight, appear to require markedly larger complexity. These properties can be subtly modulated by local modifications to the sequence rather than global changes in molecular architecture. In order to address the evolution and development of ion channels, we focus on identifying those protein domains that are commonly associated with ion channel proteins and are conserved throughout the three main domains of life (Eukarya, Prokarya, and Archaea). We discuss the potassium-sodium-calcium superfamily of voltage-gated ion channels, mechanosensitive channels, porins, and ABC-transporters and argue that these families of membrane channels have sufficiently universal architectures that they can readily adapt to the diverse functional demands arising during evolution.

RNA catalysis and the origins of life

NASA Technical Reports Server (NTRS)

Orgel, Leslie E.

1986-01-01

The role of RNA catalysis in the origins of life is considered in connection with the discovery of riboszymes, which are RNA molecules that catalyze sequence-specific hydrolysis and transesterification reactions of RNA substrates. Due to this discovery, theories positing protein-free replication as preceding the appearance of the genetic code are more plausible. The scope of RNA catalysis in biology and chemistry is discussed, and it is noted that the development of methods to select (or predict) RNA sequences with preassigned catalytic functions would be a major contribution to the study of life's origins.

Philosophical Approaches towards Sciences of Life in Early Cybernetics

NASA Astrophysics Data System (ADS)

Montagnini, Leone

2008-07-01

The article focuses on the different conceptual and philosophical approaches towards the sciences of life operating in the backstage of Early Cybernetics. After a short reconstruction of the main steps characterizing the origins of Cybernetics, from 1940 until 1948, the paper examines the complementary conceptual views between Norbert Wiener and John von Neumann, as a "fuzzy thinking" versus a "logical thinking", and the marked difference between the "methodological individualism" shared by both of them versus the "methodological collectivism" of most of the numerous scientists of life and society attending the Macy Conferences on Cybernetics. The main thesis sustained here is that these different approaches, quite invisible to the participants, were different, maybe even opposite, but they could provoke clashes, as well as cooperate in a synergic way.

Early Life Stages

EPA Pesticide Factsheets

Childhood should be viewed as a sequence of lifestages, from birth through infancy and adolescence. When assessing early life risks, consideration is given to risks resulting from fetal exposure via the pregnant mother, as well as postnatal exposures.

The ancient history of the structure of ribonuclease P and the early origins of Archaea

PubMed Central

2010-01-01

Background Ribonuclease P is an ancient endonuclease that cleaves precursor tRNA and generally consists of a catalytic RNA subunit (RPR) and one or more proteins (RPPs). It represents an important macromolecular complex and model system that is universally distributed in life. Its putative origins have inspired fundamental hypotheses, including the proposal of an ancient RNA world. Results To study the evolution of this complex, we constructed rooted phylogenetic trees of RPR molecules and substructures and estimated RPP age using a cladistic method that embeds structure directly into phylogenetic analysis. The general approach was used previously to study the evolution of tRNA, SINE RNA and 5S rRNA, the origins of metabolism, and the evolution and complexity of the protein world, and revealed here remarkable evolutionary patterns. Trees of molecules uncovered the tripartite nature of life and the early origin of archaeal RPRs. Trees of substructures showed molecules originated in stem P12 and were accessorized with a catalytic P1-P4 core structure before the first substructure was lost in Archaea. This core currently interacts with RPPs and ancient segments of the tRNA molecule. Finally, a census of protein domain structure in hundreds of genomes established RPPs appeared after the rise of metabolic enzymes at the onset of the protein world. Conclusions The study provides a detailed account of the history and early diversification of a fundamental ribonucleoprotein and offers further evidence in support of the existence of a tripartite organismal world that originated by the segregation of archaeal lineages from an ancient community of primordial organisms. PMID:20334683

How the discovery of ribozymes cast RNA in the roles of both chicken and egg in origin-of-life theories.

PubMed

Sankaran, Neeraja

2012-12-01

Scientific theories about the origin-of-life theories have historically been characterized by the chicken-and-egg problem of which essential aspect of life was the first to appear, replication or self-sustenance. By the 1950s the question was cast in molecular terms and DNA and proteins had come to represent the carriers of the two functions. Meanwhile, RNA, the other nucleic acid, had played a capricious role in origin theories. Because it contained building blocks very similar to DNA, biologists recognized early that RNA could store information in its linear sequences. With the discovery in the 1980s that RNA molecules were capable of biological catalysis, a function hitherto ascribed to proteins alone, RNA took on the role of the single entity that could act as both chicken and egg. Within a few years of the discovery of these catalytic RNAs (ribozymes) scientists had formulated an RNA World hypothesis that posited an early phase in the evolution of life where all key functions were performed by RNA molecules. This paper traces the history the role of RNA in origin-of-life theories with a focus on how the discovery of ribozymes influenced the discourse. Copyright © 2012 Elsevier Ltd. All rights reserved.

Origin and evolution of life on terrestrial planets.

PubMed

Brack, A; Horneck, G; Cockell, C S; Bérces, A; Belisheva, N K; Eiroa, Carlos; Henning, Thomas; Herbst, Tom; Kaltenegger, Lisa; Léger, Alain; Liseau, Réne; Lammer, Helmut; Selsis, Franck; Beichman, Charles; Danchi, William; Fridlund, Malcolm; Lunine, Jonathan; Paresce, Francesco; Penny, Alan; Quirrenbach, Andreas; Röttgering, Huub; Schneider, Jean; Stam, Daphne; Tinetti, Giovanna; White, Glenn J

2010-01-01

The ultimate goal of terrestrial planet-finding missions is not only to discover terrestrial exoplanets inside the habitable zone (HZ) of their host stars but also to address the major question as to whether life may have evolved on a habitable Earth-like exoplanet outside our Solar System. We note that the chemical evolution that finally led to the origin of life on Earth must be studied if we hope to understand the principles of how life might evolve on other terrestrial planets in the Universe. This is not just an anthropocentric point of view: the basic ingredients of terrestrial life, that is, reduced carbon-based molecules and liquid H(2)O, have very specific properties. We discuss the origin of life from the chemical evolution of its precursors to the earliest life-forms and the biological implications of the stellar radiation and energetic particle environments. Likewise, the study of the biological evolution that has generated the various life-forms on Earth provides clues toward the understanding of the interconnectedness of life with its environment.

African ancestry, early life exposures, and respiratory morbidity in early childhood.

PubMed

Kumar, R; Tsai, H-J; Hong, X; Gignoux, C; Pearson, C; Ortiz, K; Fu, M; Pongracic, J A; Burchard, E G; Bauchner, H; Wang, X

2012-02-01

Racial disparities persist in early childhood wheezing and cannot be completely explained by known risk factors. To evaluate the associations of genetic ancestry and self-identified race with early childhood recurrent wheezing, accounting for socio-economic status (SES) and early life exposures. We studied 1034 children in an urban, multi-racial, prospective birth cohort. Multivariate logistic regression was used to evaluate the association of genetic ancestry as opposed to self-identified race with recurrent wheezing (>3 episodes). Sequential models accounted for demographic, socio-economic factors and early life risk factors. Genetic ancestry, estimated using 150 ancestry informative markers, was expressed in deciles. Approximately 6.1% of subjects (mean age 3.1 years) experienced recurrent wheezing. After accounting for SES and demographic factors, African ancestry (OR: 1.16, 95% CI: 1.02-1.31) was significantly associated with recurrent wheezing. By self-reported race, hispanic subjects had a borderline decrease in risk of wheeze compared with African Americans (OR: 0.44, 95% CI: 0.19-1.00), whereas white subjects (OR: 0.46, 95% CI: 0.14-1.57) did not have. After further adjustment for known confounders and early life exposures, both African (OR: 1.19, 95% CI: 1.05-1.34) and European ancestry (OR: 0.84, 95% CI: 0.74-0.94) retained a significant association with recurrent wheezing, as compared with self-identified race (OR(whites) : 0.31, 95% CI: 0.09-1.14; OR(hispanic) : 0.47, 95% CI: 0.20-1.08). There were no significant interactions between ancestry and early life factors on recurrent wheezing. In contrast to self-identified race, African ancestry remained a significant, independent predictor of early childhood wheezing after accounting for early life and other known risk factors associated with lung function changes and asthma. Genetic ancestry may be a powerful way to evaluate wheezing disparities and a proxy for differentially distributed genetic and

African ancestry, early life exposures, and respiratory morbidity in early childhood

PubMed Central

Kumar, R.; Tsai, H.-J.; Hong, X.; Gignoux, C.; Pearson, C.; Ortiz, K.; Fu, M.; Pongracic, J. A.; Burchard, E. G.; Bauchner, H.; Wang, X.

2012-01-01

Summary Background Racial disparities persist in early childhood wheezing and cannot be completely explained by known risk factors. Objective To evaluate the associations of genetic ancestry and self-identified race with early childhood recurrent wheezing, accounting for socio-economic status (SES) and early life exposures. Methods We studied 1034 children in an urban, multi-racial, prospective birth cohort. Multivariate logistic regression was used to evaluate the association of genetic ancestry as opposed to self-identified race with recurrent wheezing (>3 episodes). Sequential models accounted for demographic, socio-economic factors and early life risk factors. Genetic ancestry, estimated using 150 ancestry informative markers, was expressed in deciles. Results Approximately 6.1% of subjects (mean age 3.1 years) experienced recurrent wheezing. After accounting for SES and demographic factors, African ancestry (OR: 1.16, 95% CI: 1.02–1.31) was significantly associated with recurrent wheezing. By self-reported race, hispanic subjects had a borderline decrease in risk of wheeze compared with African Americans (OR: 0.44, 95% CI: 0.19–1.00), whereas white subjects (OR: 0.46, 95% CI: 0.14–1.57) did not have. After further adjustment for known confounders and early life exposures, both African (OR: 1.19, 95% CI: 1.05–1.34) and European ancestry (OR: 0.84, 95% CI: 0.74–0.94) retained a significant association with recurrent wheezing, as compared with self-identified race (ORwhites: 0.31, 95% CI: 0.09–1.14; ORhispanic: 0.47, 95% CI: 0.20–1.08). There were no significant interactions between ancestry and early life factors on recurrent wheezing. Conclusions and Clinical Relevance In contrast to self-identified race, African ancestry remained a significant, independent predictor of early childhood wheezing after accounting for early life and other known risk factors associated with lung function changes and asthma. Genetic ancestry may be a powerful way to

Early-life nutritional effects on the female reproductive system.

PubMed

Chan, K A; Tsoulis, M W; Sloboda, D M

2015-02-01

There is now considerable epidemiological and experimental evidence indicating that early-life environmental conditions, including nutrition, affect subsequent development in later life. These conditions induce highly integrated responses in endocrine-related homeostasis, resulting in persistent changes in the developmental trajectory producing an altered adult phenotype. Early-life events trigger processes that prepare the individual for particular circumstances that are anticipated in the postnatal environment. However, where the intrauterine and postnatal environments differ markedly, such modifications to the developmental trajectory may prove maladaptive in later life. Reproductive maturation and function are similarly influenced by early-life events. This should not be surprising, because the primordial follicle pool is established early in life and is thus vulnerable to early-life events. Results of clinical and experimental studies have indicated that early-life adversity is associated with a decline in ovarian follicular reserve, changes in ovulation rates, and altered age at onset of puberty. However, the underlying mechanisms regulating the relationship between the early-life developmental environment and postnatal reproductive development and function are unclear. This review examines the evidence linking early-life nutrition and effects on the female reproductive system, bringing together clinical observations in humans and experimental data from targeted animal models. © 2015 Society for Endocrinology.

Non-terrestrial origin of life: a transformative research paradigm shift.

PubMed

Wickramasinghe, N Chandra; Trevors, J T

2013-06-01

Theories and hypotheses in science are continually subject to verification, critical re-evaluation, revision and indeed evolution, in response to new observations and discoveries. Theories of the origin of life have been more constrained than other scientific theories and hypotheses in this regard, through the force of social and cultural pressures. There has been a tendency to adhere too rigidly to a class of theory that demands a purely terrestrial origin of life. For nearly five decades evidence in favour of a non-terrestrial origin of life and panspermia has accumulated which has not been properly assessed. A point has now been reached that demands the serious attention of biologists to a possibly transformative paradigm shift of the question of the origin of life, with profound implications across many disciplines.

Preventing Obesity Across Generations: Evidence for Early Life Intervention.

PubMed

Haire-Joshu, Debra; Tabak, Rachel

2016-01-01

To prevent the intergenerational transfer of obesity and end the current epidemic, interventions are needed across the early life stages, from preconception to prenatal to infancy through the age of 2 years. The foundation for obesity is laid in early life by actions and interactions passed from parent to child that have long-lasting biologic and behavioral consequences. The purpose of this paper is to examine the best evidence about (a) factors in parents and offspring that promote obesity during the early life stages, (b) the social determinants and dimensions of obesity in early life, (c) promising and effective interventions for preventing obesity in early life, and (d) opportunities for future research into strategies to disrupt the intergenerational cycle of obesity that begins early in life. The pathway for halting the intergenerational obesity epidemic requires the discovery and development of evidence-based interventions that can act across multiple dimensions of influence on early life.

Preventing Obesity Across Generations: Evidence for Early Life Intervention

PubMed Central

Haire-Joshu, Debra; Tabak, Rachel

2017-01-01

To prevent the intergenerational transfer of obesity and end the current epidemic, interventions are needed across the early life stages, from preconception to prenatal to infancy through the age of 2 years. The foundation for obesity is laid in early life by actions and interactions passed from parent to child that have long-lasting biologic and behavioral consequences. The purpose of this paper is to examine the best evidence about (a) factors in parents and offspring that promote obesity during the early life stages, (b) the social determinants and dimensions of obesity in early life, (c) promising and effective interventions for preventing obesity in early life, and (d) opportunities for future research into strategies to disrupt the intergenerational cycle of obesity that begins early in life. The pathway for halting the intergenerational obesity epidemic requires the discovery and development of evidence-based interventions that can act across multiple dimensions of influence on early life. PMID:26989828

A developmental perspective on early-life exposure to neurotoxicants.

PubMed

Bellinger, David C; Matthews-Bellinger, Julia A; Kordas, Katarzyna

2016-09-01

Studies of early-life neurotoxicant exposure have not been designed, analyzed, or interpreted in the context of a fully developmental perspective. The goal of this paper is to describe the key principles of a developmental perspective and to use examples from the literature to illustrate the relevance of these principles to early-life neurotoxicant exposures. Four principles are discussed: 1) the effects of early-life neurotoxicant exposure depend on a child's developmental context; 2) deficits caused by early-life exposure initiate developmental cascades that can lead to pathologies that differ from those observed initially; 3) early-life neurotoxicant exposure has intra-familial and intergenerational impacts; 4) the impacts of early-life neurotoxicant exposure influence a child's ability to respond to future insults. The first principle is supported by considerable evidence, but the other three have received much less attention. Incorporating a developmental perspective in studies of early-life neurotoxicant exposures requires prospective collection of data on a larger array of covariates than usually considered, using analytical approaches that acknowledge the transactional processes between a child and the environment and the phenomenon of developmental cascades. Consideration of early-life neurotoxicant exposure within a developmental perspective reveals that many issues remain to be explicated if we are to achieve a deep understanding of the societal health burden associated with early-life neurotoxicant exposures. Copyright © 2016 Elsevier Ltd. All rights reserved.

An origin of life on Mars.

PubMed

McKay, Christopher P

2010-04-01

Evidence of past liquid water on the surface of Mars suggests that this world once had habitable conditions and leads to the question of life. If there was life on Mars, it would be interesting to determine if it represented a separate origin from life on Earth. To determine the biochemistry and genetics of life on Mars requires that we have access to an organism or the biological remains of one-possibly preserved in ancient permafrost. A way to determine if organic material found on Mars represents the remains of an alien biological system could be based on the observation that biological systems select certain organic molecules over others that are chemically similar (e.g., chirality in amino acids).

Iron catalysis at the origin of life.

PubMed

Camprubi, Eloi; Jordan, Sean F; Vasiliadou, Rafaela; Lane, Nick

2017-06-01

Iron-sulphur proteins are ancient and drive fundamental processes in cells, notably electron transfer and CO 2 fixation. Iron-sulphur minerals with equivalent structures could have played a key role in the origin of life. However, the 'iron-sulphur world' hypothesis has had a mixed reception, with questions raised especially about the feasibility of a pyrites-pulled reverse Krebs cycle. Phylogenetics suggests that the earliest cells drove carbon and energy metabolism via the acetyl CoA pathway, which is also replete in Fe(Ni)S proteins. Deep differences between bacteria and archaea in this pathway obscure the ancestral state. These differences make sense if early cells depended on natural proton gradients in alkaline hydrothermal vents. If so, the acetyl CoA pathway diverged with the origins of active ion pumping, and ancestral CO 2 fixation might have been equivalent to methanogens, which depend on a membrane-bound NiFe hydrogenase, energy converting hydrogenase. This uses the proton-motive force to reduce ferredoxin, thence CO 2 . The mechanism suggests that pH could modulate reduction potential at the active site of the enzyme, facilitating the difficult reduction of CO 2 by H 2 . This mechanism could be generalised under abiotic conditions so that steep pH differences across semi-conducting Fe(Ni)S barriers drives not just the first steps of CO 2 fixation to C1 and C2 organics such as CO, CH 3 SH and CH 3 COSH, but a series of similar carbonylation and hydrogenation reactions to form longer chain carboxylic acids such as pyruvate, oxaloacetate and α-ketoglutarate, as in the incomplete reverse Krebs cycle found in methanogens. We suggest that the closure of a complete reverse Krebs cycle, by regenerating acetyl CoA directly, displaced the acetyl CoA pathway from many modern groups. A later reliance on acetyl CoA and ATP eliminated the need for the proton-motive force to drive most steps of the reverse Krebs cycle. © 2017 IUBMB Life, 69(6):373-381, 2017. �

Good daily habits during the early stages of life determine success throughout life.

PubMed

Kohyama, Jun

2016-01-01

This paper assesses hypothesis that sufficient sleep duration and proper circadian rhythms during the early stages of life are indispensable to a successful life. Successful life was defined according to the famous cohort studies of Mischel's and Dunedin. To assess the hypothesis, neuronal elements presumably affecting early daily habits and successful life are reviewed. The effect of sufficient sleep duration and proper circadian rhythms during early stages of life on the development of the prefrontal cortex has been found to be the key issue to verify the hypothesis. Socioeconomic status is found to be another issue to be studied.

Life sciences and space research 24 (4): Planetary biology and origins of life; Topical Meeting of the COSPAR Interdisciplinary Scientific Commission F (Meeting F3) of the COSPAR Plenary Meeting, 29th, Washington, DC, Aug. 28-Sep. 5, 1992

NASA Technical Reports Server (NTRS)

Greenberg, J. M. (Editor); Oro, J. (Editor); Brack, A. (Editor); Devincenzi, D. L. (Editor); Banin, A. (Editor); Friedmann, E. I. (Editor); Rummel, J. D. (Editor); Raulin, F. (Editor); Mckay, C. P. (Editor); Baltscheffsky, H. (Editor)

1995-01-01

The proceedings include sessions on extraterrestrial organic chemistry and the origins of life; life on Mars: past, present and future; planetary protection of Mars missions; chemical evolution on Titan; origins and early evolution of biological (a) energy transduction and membranes (b) information and catalysis; and carbon chemistry and isotopic fractionations in astrophysical environments.

The Early Years: "Life" Science

ERIC Educational Resources Information Center

Ashbrook, Peggy

2013-01-01

Talking about death as part of a life cycle is often ignored or spoken about in hushed tones in early childhood. Books with "life cycle" in the title often do not include the death of the living organism in the information about the cycle. The concept of a complete life cycle does not appear in "A Framework for K-12 Science…

Origins of Life: Open Questions and Debates

NASA Astrophysics Data System (ADS)

Brack, André

2017-10-01

Stanley Miller demonstrated in 1953 that it was possible to form amino acids from methane, ammonia, and hydrogen in water, thus launching the ambitious hope that chemists would be able to shed light on the origins of life by recreating a simple life form in a test tube. However, it must be acknowledged that the dream has not yet been accomplished, despite the great volume of effort and innovation put forward by the scientific community. A minima, primitive life can be defined as an open chemical system, fed with matter and energy, capable of self-reproduction (i.e., making more of itself by itself), and also capable of evolving. The concept of evolution implies that chemical systems would transfer their information fairly faithfully but make some random errors. If we compared the components of primitive life to parts of a chemical automaton, we could conceive that, by chance, some parts self-assembled to generate an automaton capable of assembling other parts to produce a true copy. Sometimes, minor errors in the building generated a more efficient automaton, which then became the dominant species. Quite different scenarios and routes have been followed and tested in the laboratory to explain the origin of life. There are two schools of thought in proposing the prebiotic supply of organics. The proponents of a metabolism-first call for the spontaneous formation of simple molecules from carbon dioxide and water to rapidly generate life. In a second hypothesis, the primeval soup scenario, it is proposed that rather complex organic molecules accumulated in a warm little pond prior to the emergence of life. The proponents of the primeval soup or replication first approach are by far the more active. They succeeded in reconstructing small-scale versions of proteins, membranes, and RNA. Quite different scenarios have been proposed for the inception of life: the RNA world, an origin within droplets, self-organization counteracting entropy, or a stochastic approach merging

Where/when/how did life begin? A philosophical key for systematizing theories on the origin of life

NASA Astrophysics Data System (ADS)

Świeżyński, Adam

2016-10-01

The question of the origin of life interested people for centuries. All existing views on this subject can be classified into different areas of human knowledge about the world: natural sciences, philosophy, and theology (religion). It is interesting to look at them closer and to classify all the typical groups of the theories about the origins of life. We can then see links existing between them and relationships that indicate their own nature. Nowadays, driving forces of prebiological chemical evolution and the mode of explanation of the transition 'non-life into life' give a great variety of solutions. The differences between the theories, however, as well as the current controversies in the scientific community (what 'in the beginning' was?; where and when the prebiotic evolution may took place? etc.) will be shown as of secondary importance for the theories' systematization in comparison with several much more profound philosophical assumptions underlying the origin-of-life-studies. My proposal to organize and classify different types of the theories of genesis of life allows for extracting conceptions of different kind: metaphysical and scientific, and also for comparing them with each other. Some of them answer the question of the emergence of life in general and others on the question of the origin of life on the Earth only. In the perspective of contemporary scientific research on the origin of life it seems interesting that two main ideas concerning the problem of the origin of life, spontaneous generation and panspermia, are still present as presuppositions of certain theories but have been modified. Thus a 'philosophical key' seems to be the most appropriate to systematize all kinds of theories on the origin of life. This paper is an attempt to justify the position adopted. Most important conclusion is that the philosophical basis or implications, which are irreducibly present and possible to be found within the scientific theories of the origin of life

An Origin of Life on Mars

PubMed Central

McKay, Christopher P.

2010-01-01

Evidence of past liquid water on the surface of Mars suggests that this world once had habitable conditions and leads to the question of life. If there was life on Mars, it would be interesting to determine if it represented a separate origin from life on Earth. To determine the biochemistry and genetics of life on Mars requires that we have access to an organism or the biological remains of one—possibly preserved in ancient permafrost. A way to determine if organic material found on Mars represents the remains of an alien biological system could be based on the observation that biological systems select certain organic molecules over others that are chemically similar (e.g., chirality in amino acids). PMID:20452949

Role of Phosphorus Minerals in the Origin of Life on Earth

NASA Astrophysics Data System (ADS)

Gull, M.; Pasek, M. A.

2013-12-01

In the origin of life, phosphorus (P) plays a vital role as it is a key biologic element (1). However, a big question still remains as to how P was incorporated into the first biomolecules as the availability of dissolved P in water is low. Orthophosphate minerals such as apatite, whitelockite and monetite are the major carriers of phosphate on Earth, but these are poorly soluble in water and are inert. The recent discovery of phosphite in Archean rocks (2) suggests that it is likely that some other source of P was present on the early Earth which could very well mix with Hadean Ocean to generate biomolecules. The meteoritic mineral schreibersite (SC thereafter) may have provided reduced P that would corrode into water and generate reactive inorganic P. In this study we present the significance of some important P minerals including apatite, whitelockite, monazite, struvite, monetite and meteoritic mineral SC (or its synthetic analogue Fe3P). Two major aspects of these P minerals were studied; first the release of P into water and second whether phosphorylation of organic compound (glycerol) could be carried out. It was seen all the phosphate minerals such as apatite, whitelockite, monazite and monetite when heated (65-75oC for 8-10 days) with an aqueous solution of 0.5 M glycerol gave no prominent phosphorylated products (P31NMR & mass spectrometry) and released very little amount of phosphate into water and remained inert. Struvite on heating with glycerol gave around 8-10 % of glycerol monophosphates along with phosphate release in the water. When SC (or Fe3P) was heated in an aqueous solution of glycerol it not only yielded 3-6 % glycerol monophosphates but also some glycerol-di-phosphate along with rich species of inorganic P compounds. SC from the meteorite Seymchan also demonstrated phosphorylation of glycerol. Since the prebiotic role of struvite mineral as a prebiotic P mineral is not clearly known (3), this suggests SC was a potential prebiotic P source

Quantifying the origins of life on a planetary scale

NASA Astrophysics Data System (ADS)

Scharf, Caleb; Cronin, Leroy

2016-07-01

A simple, heuristic formula with parallels to the Drake Equation is introduced to help focus discussion on open questions for the origins of life in a planetary context. This approach indicates a number of areas where quantitative progress can be made on parameter estimation for determining origins of life probabilities, based on constraints from Bayesian approaches. We discuss a variety of “microscale” factors and their role in determining “macroscale” abiogenesis probabilities on suitable planets. We also propose that impact ejecta exchange between planets with parallel chemistries and chemical evolution could in principle amplify the development of molecular complexity and abiogenesis probabilities. This amplification could be very significant, and both bias our conclusions about abiogenesis probabilities based on the Earth and provide a major source of variance in the probability of life arising in planetary systems. We use our heuristic formula to suggest a number of observational routes for improving constraints on origins of life probabilities.

Quantifying the origins of life on a planetary scale

PubMed Central

Scharf, Caleb; Cronin, Leroy

2016-01-01

A simple, heuristic formula with parallels to the Drake Equation is introduced to help focus discussion on open questions for the origins of life in a planetary context. This approach indicates a number of areas where quantitative progress can be made on parameter estimation for determining origins of life probabilities, based on constraints from Bayesian approaches. We discuss a variety of “microscale” factors and their role in determining “macroscale” abiogenesis probabilities on suitable planets. We also propose that impact ejecta exchange between planets with parallel chemistries and chemical evolution could in principle amplify the development of molecular complexity and abiogenesis probabilities. This amplification could be very significant, and both bias our conclusions about abiogenesis probabilities based on the Earth and provide a major source of variance in the probability of life arising in planetary systems. We use our heuristic formula to suggest a number of observational routes for improving constraints on origins of life probabilities. PMID:27382156

Quantifying the origins of life on a planetary scale.

PubMed

Scharf, Caleb; Cronin, Leroy

2016-07-19

A simple, heuristic formula with parallels to the Drake Equation is introduced to help focus discussion on open questions for the origins of life in a planetary context. This approach indicates a number of areas where quantitative progress can be made on parameter estimation for determining origins of life probabilities, based on constraints from Bayesian approaches. We discuss a variety of "microscale" factors and their role in determining "macroscale" abiogenesis probabilities on suitable planets. We also propose that impact ejecta exchange between planets with parallel chemistries and chemical evolution could in principle amplify the development of molecular complexity and abiogenesis probabilities. This amplification could be very significant, and both bias our conclusions about abiogenesis probabilities based on the Earth and provide a major source of variance in the probability of life arising in planetary systems. We use our heuristic formula to suggest a number of observational routes for improving constraints on origins of life probabilities.

RNA Relics and Origin of Life

PubMed Central

Demongeot, Jacques; Glade, Nicolas; Moreira, Andrés; Vial, Laurent

2009-01-01

A number of small RNA sequences, located in different non-coding sequences and highly preserved across the tree of life, have been suggested to be molecular fossils, of ancient (and possibly primordial) origin. On the other hand, recent years have revealed the existence of ubiquitous roles for small RNA sequences in modern organisms, in functions ranging from cell regulation to antiviral activity. We propose that a single thread can be followed from the beginning of life in RNA structures selected only for stability reasons through the RNA relics and up to the current coevolution of RNA sequences; such an understanding would shed light both on the history and on the present development of the RNA machinery and interactions. After presenting the evidence (by comparing their sequences) that points toward a common thread, we discuss a scenario of genome coevolution (with emphasis on viral infectious processes) and finally propose a plan for the reevaluation of the stereochemical theory of the genetic code; we claim that it may still be relevant, and not only for understanding the origin of life, but also for a comprehensive picture of regulation in present-day cells. PMID:20111682

Mineral Surface-Templated Self-Assembling Systems: Case Studies from Nanoscience and Surface Science towards Origins of Life Research.

PubMed

Gillams, Richard J; Jia, Tony Z

2018-05-08

An increasing body of evidence relates the wide range of benefits mineral surfaces offer for the development of early living systems, including adsorption of small molecules from the aqueous phase, formation of monomeric subunits and their subsequent polymerization, and supramolecular assembly of biopolymers and other biomolecules. Each of these processes was likely a necessary stage in the emergence of life on Earth. Here, we compile evidence that templating and enhancement of prebiotically-relevant self-assembling systems by mineral surfaces offers a route to increased structural, functional, and/or chemical complexity. This increase in complexity could have been achieved by early living systems before the advent of evolvable systems and would not have required the generally energetically unfavorable formation of covalent bonds such as phosphodiester or peptide bonds. In this review we will focus on various case studies of prebiotically-relevant mineral-templated self-assembling systems, including supramolecular assemblies of peptides and nucleic acids, from nanoscience and surface science. These fields contain valuable information that is not yet fully being utilized by the origins of life and astrobiology research communities. Some of the self-assemblies that we present can promote the formation of new mineral surfaces, similar to biomineralization, which can then catalyze more essential prebiotic reactions; this could have resulted in a symbiotic feedback loop by which geology and primitive pre-living systems were closely linked to one another even before life’s origin. We hope that the ideas presented herein will seed some interesting discussions and new collaborations between nanoscience/surface science researchers and origins of life/astrobiology researchers.

Darwin's warm little pond revisited: from molecules to the origin of life.

PubMed

Follmann, Hartmut; Brownson, Carol

2009-11-01

All known cosmic and geological conditions and laws of chemistry and thermodynamics allow that complex organic matter could have formed spontaneously on pristine planet Earth about 4,000 mya. Simple gasses and minerals on the surface and in oceans of the early Earth reacted and were eventually organized in supramolecular aggregates and enveloped cells that evolved into primitive forms of life. Chemical evolution, which preceded all species of extant organisms, is a fact. In this review, we have concentrated on experimental and theoretical research published over the last two decades, which has added a wealth of new details and helped to close gaps in our previous understanding of this multifaceted field. Recent exciting progress in the molecular and genetic analyses of existing life, in particular microorganisms of ancient origin, even supports the possibility that a cellular, self-reproducing common ancestor might be assembled and resurrected in anaerobic cultures at some time in the future. Charles Darwin did not, and indeed, could not, address and specify the earliest phases of life which preceded the Origin of Species. However, in a famous letter, he sketched "a warm little pond with all sorts of... (chemicals, in which) ...a protein was chemically formed." We try to trace the impact of his charming clear-sighted metaphor up to the present time.

Darwin's warm little pond revisited: from molecules to the origin of life

NASA Astrophysics Data System (ADS)

Follmann, Hartmut; Brownson, Carol

2009-11-01

All known cosmic and geological conditions and laws of chemistry and thermodynamics allow that complex organic matter could have formed spontaneously on pristine planet Earth about 4,000 mya. Simple gasses and minerals on the surface and in oceans of the early Earth reacted and were eventually organized in supramolecular aggregates and enveloped cells that evolved into primitive forms of life. Chemical evolution, which preceded all species of extant organisms, is a fact. In this review, we have concentrated on experimental and theoretical research published over the last two decades, which has added a wealth of new details and helped to close gaps in our previous understanding of this multifaceted field. Recent exciting progress in the molecular and genetic analyses of existing life, in particular microorganisms of ancient origin, even supports the possibility that a cellular, self-reproducing common ancestor might be assembled and resurrected in anaerobic cultures at some time in the future. Charles Darwin did not, and indeed, could not, address and specify the earliest phases of life which preceded the Origin of Species. However, in a famous letter, he sketched “a warm little pond with all sorts of… (chemicals, in which) …a protein was chemically formed.” We try to trace the impact of his charming clear-sighted metaphor up to the present time.

Early Adolescent Temperament, Parental Monitoring, and Substance Use in Mexican-Origin Adolescents

PubMed Central

Clark, D. Angus; Donnellan, M. Brent; Robins, Richard W.; Conger, Rand D.

2015-01-01

Previous studies suggest that temperamental dispositions are associated with substance use. However, most research supporting this association has relied on European American samples (Stautz & Cooper, 2013). We addressed this gap by evaluating the prospective relations between 5th grade temperament and 9th grade substance use in a longitudinal sample of Mexican-origin youth (N = 674). Effortful control and trait aggressiveness predicted 9th grade substance use, intentions, and expectations, even after controlling for 5th grade substance use. Additionally, we found an interaction between temperament and parental monitoring such that monitoring is a protective factor for early substance use primarily for youth with temperamental tendencies associated with risk for substance use (e.g., low effortful control and aggression). Results add to the growing literature demonstrating that early manifestations of self-control are related to consequential life outcomes. PMID:25841175

Question 1: Origin of Life and the Living State

NASA Astrophysics Data System (ADS)

Kauffman, Stuart

2007-10-01

The aim of this article is to discuss four topics: First, the origin of molecular reproduction. Second, the origin of agency the capacity of a system to act on its own behalf. Agency is a stunning feature of human and some wider range of life. Third, to discuss a still poorly articulated feature of life noticed by the philosopher Immanuel Kant over 200 years ago: A self propagating organization of process. We have no theory for this aspect of life, yet it is central to life. Fourth, I will discuss constraints, as in Schroedinger’s aperiodic crystal (Schroedinger E, What is life? The physical aspect of the living cell, 1944), as information, part of the total non-equilibrium union of matter, energy, work, work cycles, constraints, and information that appear to comprise the living state.

Question 1: origin of life and the living state.

PubMed

Kauffman, Stuart

2007-10-01

The aim of this article is to discuss four topics: First, the origin of molecular reproduction. Second, the origin of agency - the capacity of a system to act on its own behalf. Agency is a stunning feature of human and some wider range of life. Third, to discuss a still poorly articulated feature of life noticed by the philosopher Immanuel Kant over 200 years ago: A self propagating organization of process. We have no theory for this aspect of life, yet it is central to life. Fourth, I will discuss constraints, as in Schroedinger's aperiodic crystal (Schroedinger E, What is life? The physical aspect of the living cell, 1944), as information, part of the total non-equilibrium union of matter, energy, work, work cycles, constraints, and information that appear to comprise the living state.

Autocatalytic sets and chemical organizations: modeling self-sustaining reaction networks at the origin of life

NASA Astrophysics Data System (ADS)

Hordijk, Wim; Steel, Mike; Dittrich, Peter

2018-01-01

Two related but somewhat different approaches have been proposed to formalize the notion of a self-sustaining chemical reaction network. One is the notion of collectively autocatalytic sets, formalized as RAF theory, and the other is chemical organization theory. Both formalisms have been argued to be relevant to the origin of life. RAF sets and chemical organizations are defined differently, but previously some relationships between the two have been shown. Here, we refine and explore these connections in more detail. In particular, we show that so-called closed RAFs are chemical organizations, but that the converse is not necessarily true. We then introduce and apply a procedure to show how chemical organizations can be used to find all closed RAFs within any chemical reaction system. We end with a discussion of why and how closed RAFs could be important in the context of the origin and early evolution of life.

Early-life conditions and older adult health in low- and middle-income countries: a review

PubMed Central

McEniry, M.

2012-01-01

Population aging and subsequent projected large increases in chronic conditions will be important health concerns in low- and middle-income countries. Although evidence is accumulating, little is known regarding the impact of poor early-life conditions on older adult (50 years and older) health in these settings. A systematic review of 1141 empirical studies was conducted to identify population-based and community studies in low- and middle-income countries, which examined associations between early-life conditions and older adult health. The resulting review of 20 studies revealed strong associations between (1) in utero/early infancy exposures (independent of other early life and adult conditions) and adult heart disease and diabetes; (2) poor nutrition during childhood and difficulties in adult cognition and diabetes; (3) specific childhood illnesses such as rheumatic fever and malaria and adult heart disease and mortality; (4) poor childhood health and adult functionality/disability and chronic diseases; (5) poor childhood socioeconomic status (SES) and adult mortality, functionality/disability and cognition; and (6) parental survival during childhood and adult functionality/disability and cognition. In several instances, associations remained strong even after controlling for adult SES and lifestyle. Although exact mechanisms cannot be identified, these studies reinforce to some extent the importance of early-life environment on health at older ages. Given the paucity of cohort data from the developing world to examine hypotheses of early-life conditions and older adult health, population-based studies are relevant in providing a broad perspective on the origins of adult health. PMID:23316272

Early life determinants of frailty in old age: the Helsinki Birth Cohort Study.

PubMed

Haapanen, M J; Perälä, M M; Salonen, M K; Kajantie, E; Simonen, M; Pohjolainen, P; Eriksson, J G; von Bonsdorff, M B

2018-04-12

there is evidence suggesting that several chronic diseases have their origins in utero and that development taking place during sensitive periods may affect the aging process. We investigated whether early life determinants would be associated with frailty in old age. at a mean age of 71 years, 1,078 participants belonging to the Helsinki Birth Cohort Study were assessed for frailty according to the Fried frailty criteria. Early life measurements (birth weight, length, mother body mass index [BMI] and parity) were obtained from birth, child welfare and school health records. Multinomial regression analysis was used to assess the association between early life determinants and frailty in old age. weight, length and BMI at birth were all inversely associated with frailty in old age. A 1 kg increase in birth weight was associated with a lower relative risk ratio (RRR) of frailty (age and sex-adjusted RRR = 0.40, 95% CI: 0.19, 0.82) compared to non-frailty. Associations persisted after adjusting for several confounding factors. Compared to cohort members in the upper middle class, those who as adults worked as manual workers or belonged to the lower middle class, were at an increased risk of frailty. those who were small at birth were at an increased risk of developing frailty in old age, suggesting that frailty is at least partly programmed in early life. A less privileged socioeconomic status in adulthood was associated with an increased risk of frailty in old age.

The influence of living conditions in early life on life satisfaction in old age.

PubMed

Deindl, Christian

2013-03-01

This article examines the influence of living conditions in early life on life satisfaction in old age in eleven Western European countries. It combines the influence of individual conditions, for example housing and family background, with country characteristics in the decade of birth. Using pooled data from the second and third wave of the Survey of Health, Ageing and Retirement in Europe, multilevel models show that early life living conditions have an influence on life satisfaction in old age. Furthermore, interaction effects between current and past living conditions show that adverse living conditions strengthen the effect of early life on life satisfaction in later life and therefore are an indication of cumulative inequality over the life course. Copyright © 2012 Elsevier Ltd. All rights reserved.

Retinal vascular imaging in early life: insights into processes and risk of cardiovascular disease

PubMed Central

Li, Ling‐Jun; Ikram, Mohammad Kamran

2015-01-01

Abstract Cardiovascular disease (CVD) is the leading cause of morbidity and mortality globally. In recent years, studies have shown that the origins of CVD may be traced to vascular and metabolic processes in early life. Retinal vascular imaging is a new technology that allows detailed non‐invasive in vivo assessment and monitoring of the microvasculature. In this systematic review, we described the application of retinal vascular imaging in children and adolescents, and we examined the use of retinal vascular imaging in understanding CVD risk in early life. We reviewed all publications with quantitative retinal vascular assessment in two databases: PubMed and Scopus. Early life CVD risk factors were classified into four groups: birth risk factors, environmental risk factors, systemic risk factors and conditions linked to future CVD development. Retinal vascular changes were associated with lower birth weight, shorter gestational age, low‐fibre and high‐sugar diet, lesser physical activity, parental hypertension history, childhood hypertension, childhood overweight/obesity, childhood depression/anxiety and childhood type 1 diabetes mellitus. In summary, there is increasing evidence supporting the view that structural changes in the retinal microvasculature are associated with CVD risk factors in early life. Thus, the retina is a useful site for pre‐clinical assessment of microvascular processes that may underlie the future development of CVD in adulthood. PMID:26435039

Origin of life in a digital microcosm

NASA Astrophysics Data System (ADS)

C G, Nitash; LaBar, Thomas; Hintze, Arend; Adami, Christoph

2017-11-01

While all organisms on Earth share a common descent, there is no consensus on whether the origin of the ancestral self-replicator was a one-off event or whether it only represented the final survivor of multiple origins. Here, we use the digital evolution system Avida to study the origin of self-replicating computer programs. By using a computational system, we avoid many of the uncertainties inherent in any biochemical system of self-replicators (while running the risk of ignoring a fundamental aspect of biochemistry). We generated the exhaustive set of minimal-genome self-replicators and analysed the network structure of this fitness landscape. We further examined the evolvability of these self-replicators and found that the evolvability of a self-replicator is dependent on its genomic architecture. We also studied the differential ability of replicators to take over the population when competed against each other, akin to a primordial-soup model of biogenesis, and found that the probability of a self-replicator outcompeting the others is not uniform. Instead, progenitor (most-recent common ancestor) genotypes are clustered in a small region of the replicator space. Our results demonstrate how computational systems can be used as test systems for hypotheses concerning the origin of life. This article is part of the themed issue 'Reconceptualizing the origins of life'.

Origins of life: a problem for physics, a key issues review

NASA Astrophysics Data System (ADS)

Imari Walker, Sara

2017-09-01

The origins of life stands among the great open scientific questions of our time. While a number of proposals exist for possible starting points in the pathway from non-living to living matter, these have so far not achieved states of complexity that are anywhere near that of even the simplest living systems. A key challenge is identifying the properties of living matter that might distinguish living and non-living physical systems such that we might build new life in the lab. This review is geared towards covering major viewpoints on the origin of life for those new to the origin of life field, with a forward look towards considering what it might take for a physical theory that universally explains the phenomenon of life to arise from the seemingly disconnected array of ideas proposed thus far. The hope is that a theory akin to our other theories in fundamental physics might one day emerge to explain the phenomenon of life, and in turn finally permit solving its origins.

Universal biology and the statistical mechanics of early life.

PubMed

Goldenfeld, Nigel; Biancalani, Tommaso; Jafarpour, Farshid

2017-12-28

All known life on the Earth exhibits at least two non-trivial common features: the canonical genetic code and biological homochirality, both of which emerged prior to the Last Universal Common Ancestor state. This article describes recent efforts to provide a narrative of this epoch using tools from statistical mechanics. During the emergence of self-replicating life far from equilibrium in a period of chemical evolution, minimal models of autocatalysis show that homochirality would have necessarily co-evolved along with the efficiency of early-life self-replicators. Dynamical system models of the evolution of the genetic code must explain its universality and its highly refined error-minimization properties. These have both been accounted for in a scenario where life arose from a collective, networked phase where there was no notion of species and perhaps even individuality itself. We show how this phase ultimately terminated during an event sometimes known as the Darwinian transition, leading to the present epoch of tree-like vertical descent of organismal lineages. These examples illustrate concrete examples of universal biology: the quest for a fundamental understanding of the basic properties of living systems, independent of precise instantiation in chemistry or other media.This article is part of the themed issue 'Reconceptualizing the origins of life'. © 2017 The Author(s).

Universal biology and the statistical mechanics of early life

NASA Astrophysics Data System (ADS)

Goldenfeld, Nigel; Biancalani, Tommaso; Jafarpour, Farshid

2017-11-01

All known life on the Earth exhibits at least two non-trivial common features: the canonical genetic code and biological homochirality, both of which emerged prior to the Last Universal Common Ancestor state. This article describes recent efforts to provide a narrative of this epoch using tools from statistical mechanics. During the emergence of self-replicating life far from equilibrium in a period of chemical evolution, minimal models of autocatalysis show that homochirality would have necessarily co-evolved along with the efficiency of early-life self-replicators. Dynamical system models of the evolution of the genetic code must explain its universality and its highly refined error-minimization properties. These have both been accounted for in a scenario where life arose from a collective, networked phase where there was no notion of species and perhaps even individuality itself. We show how this phase ultimately terminated during an event sometimes known as the Darwinian transition, leading to the present epoch of tree-like vertical descent of organismal lineages. These examples illustrate concrete examples of universal biology: the quest for a fundamental understanding of the basic properties of living systems, independent of precise instantiation in chemistry or other media. This article is part of the themed issue 'Reconceptualizing the origins of life'.

Early Life Stress, Mood, and Anxiety Disorders.

PubMed

Syed, Shariful A; Nemeroff, Charles B

2017-02-01

Early life stress has been shown to exert profound short- and long-term effects on human physiology both in the central nervous system and peripherally. Early life stress has demonstrated clear association with many psychiatric disorders including major depression, posttraumatic stress disorder, and bipolar disorder. The Diagnostic and Statistics Manuel of Mental Disorders (DSM) diagnostic categorical system has served as a necessary framework for clinical service, delivery, and research, however has not been completely matching the neurobiological research perspective. Early life stress presents a complex dynamic featuring a wide spectrum of physiologic alterations: from epigenetic alterations, inflammatory changes, to dysregulation of the hypothalamic pituitary axis and has further added to the challenge of identifying biomarkers associated with psychiatric disorders. The National Institute of Mental Health's proposed Research Domain Criteria initiative incorporates a dimensional approach to assess discrete domains and constructs of behavioral function that are subserved by identifiable neural circuits. The current neurobiology of early life stress is reviewed in accordance with dimensional organization of Research Domain Criteria matrix and how the findings as a whole fit within the Research Domain Criteria frameworks.

Formamide and the origin of life

NASA Astrophysics Data System (ADS)

Saladino, Raffaele; Crestini, Claudia; Pino, Samanta; Costanzo, Giovanna; Di Mauro, Ernesto

2012-03-01

The complexity of life boils down to the definition: “self-sustained chemical system capable of undergoing Darwinian evolution” (Joyce, 1994) [1]. The term “self-sustained” implies a set of chemical reactions capable of harnessing energy from the environment, using it to carry out programmed anabolic and catabolic functions. We briefly present our opinion on the general validity of this definition. Running anabolic and catabolic functions entails complex chemical information whose stability, reproducibility and evolution constitute the core of what is dubbed genetics. Life as-we-know-it is made of the intimate interaction of metabolism and genetics, both built around the chemistry of the most common elements of the Universe (hydrogen, oxygen, nitrogen, carbon). Other elements like phosphorus and sulphur play important but ancillary and potentially replaceable roles. The reproducible interaction of metabolic and genetic cycles results in the hypercycles of organization and de-organization of chemical information that we consider living entities. In order to approach the problem of the origin of life it is therefore reasonable to start from the assumption that both metabolism and genetics had a common origin, shared a common chemical frame, were embedded in physical-chemical conditions favourable for the onset of both. The most abundant three-atoms organic compound in interstellar environment is hydrogen cyanide HCN, the most abundant three-atoms inorganic compound is water H2O. The combination of the two results in the formation of formamide H2NCOH. We have explored the chemistry of formamide in conditions compatible with the synthesis and the stability of compounds of potential pre-genetic and pre-metabolic interest. We discuss evidence showing (i) that all the compounds necessary for the build-up of nucleic acids are easily obtained abiotically, (ii) that essentially all the steps leading to the spontaneous generation of RNA are abiotically possible, (iii

Kinetics of Organic Transformations Under Mild Aqueous Conditions: Implications for the Origin of Life and Its Metabolism

NASA Technical Reports Server (NTRS)

Weber, Arthur L.

2003-01-01

The rates of thermal transformation of organic molecules containing carbon, hydrogen, and oxygen were systematically examined in order to identify the kinetic constraints that governed origin-of-life organic chemistry under mild aqueous conditions. Arrhenius plots of the kinetic data were used to estimate the reaction half-life at 50 C, and to reveal the effect of functional groups on reactivity. This survey showed that hydrocarbons and organic substances containing a single oxygenated group were kinetically the most stable (i. e. acetate decarboxylation half-life was l0(exp 18) years at 50 C); whereas, organic substances containing two oxygenated groups in which one group was a beta-positioned carbonyl group were the most reactive (i. e. acetoacetate decarboxylation half-life was l0(exp-2) years at 50 C). Of all functional groups the beta-positioned carbonyl group (aldehyde or ketone) was the strongest activating group, giving rates of reaction that were up to 10(exp 24)-times faster than rates of similar molecules lacking the beta-carbonyl group. From this knowledge of organic reactivity and the inherent constraints of autocatalytic processes, we concluded that an origins-of-life process based on autocatalytic transformation of C,H,O-substrates was constrained to using the most reactive organic molecules that contain alpha- or beta-carbonyl groups, since small autocatalytic domains of plausible catalytic power that used less reactive substrates could not carry out chemical transformations fast enough to prevent catastrophic efflux (escape) of reaction intermediates. Knowledge of the kinetics of organic transformations is useful, not only in constraining the chemistry of the earliest autocatalytic process related to the origin of life, but also in establishing the relative reactivity of organic molecules on the early Earth and other planets that may or may not be related to the origin of life.

[Thermodynamics of the origin of life, evolution and aging].

PubMed

Gladyshev, G P

2014-01-01

Briefly discusses the history of the search of thermodynamic approach to explain the origin of life, evolution and aging of living beings. The origin of life is the result of requirement by the quasi-equilibrium hierarchical thermodynamics, in particular, the supramolecular thermodynamics. The evolution and aging of living beings is accompanied with changes of chemical and supramolecular compositions of living bodies, as well as with changes in the composition and structure of all hierarchies of the living world. The thermodynamic principle of substance stability predicts the existence of a single genetic code in our universe. The thermodynamic theory optimizes physiology and medicine and recommends antiaging diets and medicines. Hierarchical thermodynamics forms the design diversity of culture and art. The thermodynamic theory of origin of life, evolution and aging is the development of Clausius-Gibbs thermodynamics. Hierarchical thermodynamics is the mirror of Darwin-Wallace's-theory.

Transgenerational latent early-life associated regulation unites environment and genetics across generations

PubMed Central

Lahiri, Debomoy K; Maloney, Bryan; Bayon, Baindu L; Chopra, Nipun; White, Fletcher A; Greig, Nigel H; Nurnberger, John I

2016-01-01

The origin of idiopathic diseases is still poorly understood. The latent early-life associated regulation (LEARn) model unites environmental exposures and gene expression while providing a mechanistic underpinning for later-occurring disorders. We propose that this process can occur across generations via transgenerational LEARn (tLEARn). In tLEARn, each person is a ‘unit’ accumulating preclinical or subclinical ‘hits’ as in the original LEARn model. These changes can then be epigenomically passed along to offspring. Transgenerational accumulation of ‘hits’ determines a sporadic disease state. Few significant transgenerational hits would accompany conception or gestation of most people, but these may suffice to ‘prime’ someone to respond to later-life hits. Hits need not produce symptoms or microphenotypes to have a transgenerational effect. Testing tLEARn requires longitudinal approaches. A recently proposed longitudinal epigenome/envirome-wide association study would unite genetic sequence, epigenomic markers, environmental exposures, patient personal history taken at multiple time points and family history. PMID:26950428

Actinides and Life's Origins.

PubMed

Adam, Zachary

2007-12-01

There are growing indications that life began in a radioactive beach environment. A geologic framework for the origin or support of life in a Hadean heavy mineral placer beach has been developed, based on the unique chemical properties of the lower-electronic actinides, which act as nuclear fissile and fertile fuels, radiolytic energy sources, oligomer catalysts, and coordinating ions (along with mineralogically associated lanthanides) for prototypical prebiotic homonuclear and dinuclear metalloenzymes. A four-factor nuclear reactor model was constructed to estimate how much uranium would have been required to initiate a sustainable fission reaction within a placer beach sand 4.3 billion years ago. It was calculated that about 1-8 weight percent of the sand would have to have been uraninite, depending on the weight percent, uranium enrichment, and quantity of neutron poisons present within the remaining placer minerals. Radiolysis experiments were conducted with various solvents with the use of uraniumand thorium-rich minerals (metatorbernite and monazite, respectively) as proxies for radioactive beach sand in contact with different carbon, hydrogen, oxygen, and nitrogen reactants. Radiation bombardment ranged in duration of exposure from 3 weeks to 6 months. Low levels of acetonitrile (estimated to be on the order of parts per billion in concentration) were conclusively identified in 2 setups and tentatively indicated in a 3(rd) by gas chromatography/mass spectrometry. These low levels have been interpreted within the context of a Hadean placer beach prebiotic framework to demonstrate the promise of investigating natural nuclear reactors as power production sites that might have assisted the origins of life on young rocky planets with a sufficiently differentiated crust/mantle structure. Future investigations are recommended to better quantify the complex relationships between energy release, radioactive grain size, fissionability, reactant phase, phosphorus

Actinides and Life's Origins

NASA Astrophysics Data System (ADS)

Adam, Zachary

2007-12-01

There are growing indications that life began in a radioactive beach environment. A geologic framework for the origin or support of life in a Hadean heavy mineral placer beach has been developed, based on the unique chemical properties of the lower-electronic actinides, which act as nuclear fissile and fertile fuels, radiolytic energy sources, oligomer catalysts, and coordinating ions (along with mineralogically associated lanthanides) for prototypical prebiotic homonuclear and dinuclear metalloenzymes. A four-factor nuclear reactor model was constructed to estimate how much uranium would have been required to initiate a sustainable fission reaction within a placer beach sand 4.3 billion years ago. It was calculated that about 1-8 weight percent of the sand would have to have been uraninite, depending on the weight percent, uranium enrichment, and quantity of neutron poisons present within the remaining placer minerals. Radiolysis experiments were conducted with various solvents with the use of uranium- and thorium-rich minerals (metatorbernite and monazite, respectively) as proxies for radioactive beach sand in contact with different carbon, hydrogen, oxygen, and nitrogen reactants. Radiation bombardment ranged in duration of exposure from 3 weeks to 6 months. Low levels of acetonitrile (estimated to be on the order of parts per billion in concentration) were conclusively identified in 2 setups and tentatively indicated in a 3rd by gas chromatography/mass spectrometry. These low levels have been interpreted within the context of a Hadean placer beach prebiotic framework to demonstrate the promise of investigating natural nuclear reactors as power production sites that might have assisted the origins of life on young rocky planets with a sufficiently differentiated crust/mantle structure. Future investigations are recommended to better quantify the complex relationships between energy release, radioactive grain size, fissionability, reactant phase, phosphorus

The Origin of Life--Did It Occur at High Temperatures

NASA Technical Reports Server (NTRS)

Miller, Stanley L.; Lazcano, Antonio

1995-01-01

A high-temperature origin of life has been proposed, largely for the reason that the hyperthermophiles are claimed to be the last common ancestor of modern organisms. Even if they are the oldest extant organisms, which is in dispute, their existence can say nothing about the temperatures of the origin of life, the RNA world, and organisms preceding the hyperthermophiles. There is no geological evidence for the physical setting of the origin of life because there are no unmetamorphosed rocks from that period. Prebiotic chemistry points to a low-temperature origin because most biochemicals decompose rather rapidly at temperatures of 100 C (e.g., half-lives are 73 min for ribose, 21 days for cytosine, and 204 days for adenine). Hyperthermophiles may appear at the base of some phylogenetic trees because they outcompeted the mesophiles when they adapted to lower temperatures, possibly due to enhanced production of heat-shock proteins.

Impacts and the origin of life

NASA Technical Reports Server (NTRS)

Oberbeck, Verne R.; Fogleman, Guy

1989-01-01

Consideration is given to the estimate of Maher and Stevenson (1988) of the time at which life could have developed on earth through chemical evolution within a time interval between impact events, assuming chemical or prebiotic evolution times of 100,000 to 10,000,000 yrs. An error in the equations used to determine the time periods between impact events in estimating this time is noted. A revised equation is presented and used to calculate the point in time at which impact events became infrequent enough for life to form. By using this equation, the finding of Maher and Stevenson that life could have first originated between 4,100 and 4,300 million years ago is changed to 3,700 to 4,000 million years ago.

Sixth Symposium on Chemical Evolution and the Origin and Evolution of Life

NASA Technical Reports Server (NTRS)

Acevedo, Sara (Editor); DeVincenzi, Donald L. (Editor); Chang, Sherwood (Editor)

1998-01-01

The 6th Symposium on Chemical Evolution and the Origin and Evolution of Life was convened at NASA Ames Research Center, November 17-20, 1997. This Symposium is convened every three years under the auspices of NASA's Exobiology Program Office. All Principal Investigators funded by this Program present their most recent research accomplishments at the Symposium. Scientific papers were presented in the following areas: cosmic evolution of the biogenic elements, prebiotic evolution (both planetary and chemical), evolution of early organisms and evolution of organisms in extreme environments, solar system exploration, and star and planet formation. The Symposium was attended by over 200 scientists from NASA centers and Universities nationwide.

Origins of life and biochemistry under high-pressure conditions.

PubMed

Daniel, Isabelle; Oger, Philippe; Winter, Roland

2006-10-01

Life on Earth can be traced back to as far as 3.8 billion years (Ga) ago. The catastrophic meteoritic bombardment ended between 4.2 and 3.9 Ga ago. Therefore, if life emerged, and we know it did, it must have emerged from nothingness in less than 400 million years. The most recent scenarios of Earth accretion predict some very unstable physico-chemical conditions at the surface of Earth, which, in such a short time period, would impede the emergence of life from a proto-biotic soup. A possible alternative would be that life originated in the depth of the proto-ocean of the Hadean Earth, under high hydrostatic pressure. The large body of water would filter harmful radiation and buffer physico-chemical variations, and therefore would provide a more stable radiation-free environment for pre-biotic chemistry. After a short introduction to Earth history, the current tutorial review presents biological and physico-chemical arguments in support of high-pressure origin for life on Earth.

Early-Life Socioeconomic Status and Adult Physiological Functioning: A Life Course Examination of Biosocial Mechanisms.

PubMed

Yang, Yang Claire; Gerken, Karen; Schorpp, Kristen; Boen, Courtney; Harris, Kathleen Mullan

2017-01-01

A growing literature has demonstrated a link between early-life socioeconomic conditions and adult health at a singular point in life. No research exists, however, that specifies the life course patterns of socioeconomic status (SES) in relation to the underlying biological processes that determine health. Using an innovative life course research design consisting of four nationally representative longitudinal datasets that collectively cover the human life span from early adolescence to old age (Add Health, MIDUS, NSHAP, and HRS), we address this scientific gap and assess how SES pathways from childhood into adulthood are associated with biophysiological outcomes in different adult life stages. For each dataset, we constructed standardized composite measures of early-life SES and adult SES and harmonized biophysiological measurements of immune and metabolic functioning. We found that the relative importance of early-life SES and adult SES varied across young, mid, and late adulthood, such that early-life SES sets a life course trajectory of socioeconomic well-being and operates through adult SES to influence health as adults age. We also documented evidence of the detrimental health effects of downward mobility and persistent socioeconomic disadvantage. These findings are the first to specify the life course patterns of SES that matter for underlying biophysiological functioning in different stages of adulthood. The study thus contributes new knowledge critical for improving population health by identifying the particular points in the life course at which interventions might be most effective in preventing disease and premature mortality.

[Problems of exobiology: the origin of life on Earth].

PubMed

Tairbekov, M G; Klimovitskiĭ, V Ia; Il'in, E A

2003-01-01

The basic problem of exobiology is origin and evolution of life as a space phenomenon. Consideration is given to the facts for the space origin, spreading in the interstellar space of and invasion of the surface of planets by organic compounds, constituents of archetypes of living systems. The authors bring up to discussion the issues of life development under the conditions of Earth, and formation of the main properties of the living organisms differing in the level of organization. Outlined are some international projects on exobiological research in experiments with bio-objects on space platforms.

From cytoplasm to environment: the inorganic ingredients for the origin of life.

PubMed

Novoselov, Alexey A; Serrano, Paloma; Pacheco, Mírian Liza Alves Forancelli; Chaffin, Michael Scott; O'Malley-James, Jack Thomas; Moreno, Susan Carla; Ribeiro, Filipe Batista

2013-03-01

Early in its history, Earth's surface developed from an uninhabitable magma ocean to a place where life could emerge. The first organisms, lacking ion transporters, fixed the composition of their cradle environment in their intracellular fluid. Later, though life adapted and spread, it preserved some qualities of its initial environment within. Modern prokaryotes could thus provide insights into the conditions of early Earth and the requirements for the emergence of life. In this work, we constrain Earth's life-forming environment through detailed analysis of prokaryotic intracellular fluid. Rigorous assessment of the constraints placed on the early Earth environment by intracellular liquid will provide insight into the conditions of abiogenesis, with implications not only for our understanding of early Earth but also the formation of life elsewhere in the Universe.

Causation and the origin of life. Metabolism or replication first?

PubMed

Pross, Addy

2004-06-01

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'.

Chemical defense of early life stages of benthic marine invertebrates.

PubMed

Lindquist, Niels

2002-10-01

Accurate knowledge of factors affecting the survival of early life stages of marine invertebrates is critically important for understanding their population dynamics and the evolution of their diverse reproductive and life-history characteristics. Chemical defense is an important determinant of survival for adult stages of many sessile benthic invertebrates, yet relatively little consideration has been given to chemical defenses at the early life stages. This review examines the taxonomic breadth of early life-stage chemical defense in relation to various life-history and reproductive characteristics, as well as possible constraints on the expression of chemical defense at certain life stages. Data on the localization of defensive secondary metabolites in larvae and the fitness-related consequences of consuming even a small amount of toxic secondary metabolites underpin proposals regarding the potential for Müllerian and Batesian mimicry to occur among marine larvae. The involvement of microbial symbionts in the chemical defense of early life stages illustrates its complexity for some species. As our knowledge of chemical defenses in early life stages grows, we will be able to more rigorously examine connections among phylogeny, chemical defenses, and the evolution of reproductive and life-history characteristics among marine invertebrates.

Shock Waves and the Origin of Life

DTIC Science & Technology

1977-01-01

Augustine, St. Thomas Aquinas, Alexander Neckham, Cardinal Damien, Paracelsus, Goethe, Copernicus , Galileo, Harvey, Francis Bacon, Descartes, Hegel and... astronomy and geology. It became thus quite inevitable that the question of how life originated be reopened and examined again in view of the newly

Effects of early life factors on the health and quality of life of older adults.

PubMed

Yilmaz, Fikriye; N Tekin, Rukiye

2018-01-01

Few studies on the effects of early life factors on the health and quality of life of adults have been conducted in Turkey. We aimed to investigate the effects of early life factors on the health and quality of life of older adults. We administered a questionnaire to 350 adults, aged 50-89 years, living in Cankaya, Ankara. The questionnaire covered sociodemographic characteristics, early life characteristics, health status, and the World Health Organization Quality of Life-Ageing scale. Data were analyzed using χ 2 tests, independent samples t-tests, one-way anova, and binary logistic regression analysis. The analyses showed that the most important risk factors for chronic disease were being ≥65 years (odds ratio (OR) = 2.34), having a chronic health problem before 18 years of age (OR = 2.48), experiencing prolonged hospitalization or bed rest before 18 years of age (OR = 2.65), and experiencing parental unconcern during early life (OR = 2.13) (P < 0.05). In addition, having a high school education or less includes people who have primary or secondary or high school diploma (OR = 1.65), having lived in a village (OR = 1.65), having a low family economic status (OR = 2.40), and having experienced one negative event (OR = 1.41) or two or more negative events (OR = 1.39) during their early lives were identified as important risk factors for low quality of life (P < 0.05). Early life factors are among the important determinants of the health and quality of life of older adults in Turkey. © 2017 Japanese Psychogeriatric Society.

Humic first, A new theory on the origin of life

NASA Astrophysics Data System (ADS)

Daei, Mohammad Ali; Daei, Manijeh

2016-04-01

necessarily they had extra terrestrial origin. In fact Ziechman et al7, in 1994 by finding humic material in Miller's experimental vessels proved that humic substances could be generate on early earth conditions by polymerizing simple organic molecules. Which evidences support our Ideas? 1- Suppose a wet land located in a warm area of primitive earth, covered with a layer of black humic materials, ready to action and reaction. Under this umbrella, basic molecules of life can interact freely and benefit from catalyzing and stimulating effects of HS. Amino and nucleic acid molecules may line up, grow, and develop mutually. Protein molecules can appear and do practices and before decaying a strand of nucleotides is ready to save their information and can rebuilt them for further practices. Thus, chemical evolution on a bed of humic acid can promote targeted, firmly and continuously towards a large network that be able to support a self replicating cell! We deliberately suggested, land and not the sea, as cradle of life. Because sodium, the most prevalent cation in oceans could not participate in primitive life, instead potassium played an important role. 2- There are strong evidences that show HS, really acted as the main elemental selector and even chairal selector for life on early earth. HS, show strong affinity and fast releasing tendency for macro nutrients (N, P, K).There is moderate affinity and releasing tendency for Ca, Mg, S. Also there is weak affinity and reluctance for liberating micronutrients. More interesting, HS generate insoluble compounds with nearly all toxic elements. As you see not only HS selected some and rejected other elements but also definite their proportions in the cell structure. 3- What is the reason of homochairality in living organism? As you know, none of previous theories in this field provided an easy explanation for this difficult and fundamental question. But, humic theory has a simple answer. Humic substances accepted some and rejected the

A Hydrothermal-Sedimentary Context for the Origin of Life

PubMed Central

Hickman-Lewis, K.; Hinman, N.; Gautret, P.; Campbell, K.A.; Bréhéret, J.G.; Foucher, F.; Hubert, A.; Sorieul, S.; Dass, A.V.; Kee, T.P.; Georgelin, T.; Brack, A.

2018-01-01

Abstract Critical to the origin of life are the ingredients of life, of course, but also the physical and chemical conditions in which prebiotic chemical reactions can take place. These factors place constraints on the types of Hadean environment in which life could have emerged. Many locations, ranging from hydrothermal vents and pumice rafts, through volcanic-hosted splash pools to continental springs and rivers, have been proposed for the emergence of life on Earth, each with respective advantages and certain disadvantages. However, there is another, hitherto unrecognized environment that, on the Hadean Earth (4.5–4.0 Ga), would have been more important than any other in terms of spatial and temporal scale: the sedimentary layer between oceanic crust and seawater. Using as an example sediments from the 3.5–3.33 Ga Barberton Greenstone Belt, South Africa, analogous at least on a local scale to those of the Hadean eon, we document constant permeation of the porous, carbonaceous, and reactive sedimentary layer by hydrothermal fluids emanating from the crust. This partially UV-protected, subaqueous sedimentary environment, characterized by physical and chemical gradients, represented a widespread system of miniature chemical reactors in which the production and complexification of prebiotic molecules could have led to the origin of life. Key Words: Origin of life—Hadean environment—Mineral surface reactions—Hydrothermal fluids—Archean volcanic sediments. Astrobiology 18, 259–293. PMID:29489386

Different nucleosomal architectures at early and late replicating origins in Saccharomyces cerevisiae.

PubMed

Soriano, Ignacio; Morafraile, Esther C; Vázquez, Enrique; Antequera, Francisco; Segurado, Mónica

2014-09-13

Eukaryotic genomes are replicated during S phase according to a temporal program. Several determinants control the timing of origin firing, including the chromatin environment and epigenetic modifications. However, how chromatin structure influences the timing of the activation of specific origins is still poorly understood. By performing high-resolution analysis of genome-wide nucleosome positioning we have identified different chromatin architectures at early and late replication origins. These different patterns are already established in G1 and are tightly correlated with the organization of adjacent transcription units. Moreover, specific early and late nucleosomal patterns are fixed robustly, even in rpd3 mutants in which histone acetylation and origin timing have been significantly altered. Nevertheless, higher histone acetylation levels correlate with the local modulation of chromatin structure, leading to increased origin accessibility. In addition, we conducted parallel analyses of replication and nucleosome dynamics that revealed that chromatin structure at origins is modulated during origin activation. Our results show that early and late replication origins present distinctive nucleosomal configurations, which are preferentially associated to different genomic regions. Our data also reveal that origin structure is dynamic and can be locally modulated by histone deacetylation, as well as by origin activation. These data offer novel insight into the contribution of chromatin structure to origin selection and firing in budding yeast.

Origin and evolution of the atmospheres of early Venus, Earth and Mars

NASA Astrophysics Data System (ADS)

Lammer, Helmut; Zerkle, Aubrey L.; Gebauer, Stefanie; Tosi, Nicola; Noack, Lena; Scherf, Manuel; Pilat-Lohinger, Elke; Güdel, Manuel; Grenfell, John Lee; Godolt, Mareike; Nikolaou, Athanasia

2018-05-01

We review the origin and evolution of the atmospheres of Earth, Venus and Mars from the time when their accreting bodies were released from the protoplanetary disk a few million years after the origin of the Sun. If the accreting planetary cores reached masses ≥ 0.5 M_Earth before the gas in the disk disappeared, primordial atmospheres consisting mainly of H_2 form around the young planetary body, contrary to late-stage planet formation, where terrestrial planets accrete material after the nebula phase of the disk. The differences between these two scenarios are explored by investigating non-radiogenic atmospheric noble gas isotope anomalies observed on the three terrestrial planets. The role of the young Sun's more efficient EUV radiation and of the plasma environment into the escape of early atmospheres is also addressed. We discuss the catastrophic outgassing of volatiles and the formation and cooling of steam atmospheres after the solidification of magma oceans and we describe the geochemical evidence for additional delivery of volatile-rich chondritic materials during the main stages of terrestrial planet formation. The evolution scenario of early Earth is then compared with the atmospheric evolution of planets where no active plate tectonics emerged like on Venus and Mars. We look at the diversity between early Earth, Venus and Mars, which is found to be related to their differing geochemical, geodynamical and geophysical conditions, including plate tectonics, crust and mantle oxidation processes and their involvement in degassing processes of secondary N_2 atmospheres. The buildup of atmospheric N_2, O_2, and the role of greenhouse gases such as CO_2 and CH_4 to counter the Faint Young Sun Paradox (FYSP), when the earliest life forms on Earth originated until the Great Oxidation Event ≈ 2.3 Gyr ago, are addressed. This review concludes with a discussion on the implications of understanding Earth's geophysical and related atmospheric evolution in relation

Trans-Agency Early-Life Exposures and Cancer Working Group

Cancer.gov

The Trans-Agency Early-Life Exposures and Cancer Working Group promotes integration of early-life events and exposures into public health cancer research, control, prevention, and policy strategies to reduce the cancer burden in the United States and globally.

The origin of cellular life.

PubMed

Ingber, D E

2000-12-01

This essay presents a scenario of the origin of life that is based on analysis of biological architecture and mechanical design at the microstructural level. My thesis is that the same architectural and energetic constraints that shape cells today also guided the evolution of the first cells and that the molecular scaffolds that support solid-phase biochemistry in modern cells represent living microfossils of past life forms. This concept emerged from the discovery that cells mechanically stabilize themselves using tensegrity architecture and that these same building rules guide hierarchical self-assembly at all size scales (Sci. Amer 278:48-57;1998). When combined with other fundamental design principles (e.g., energy minimization, topological constraints, structural hierarchies, autocatalytic sets, solid-state biochemistry), tensegrity provides a physical basis to explain how atomic and molecular elements progressively self-assembled to create hierarchical structures with increasingly complex functions, including living cells that can self-reproduce.

The origin of cellular life

NASA Technical Reports Server (NTRS)

Ingber, D. E.

2000-01-01

This essay presents a scenario of the origin of life that is based on analysis of biological architecture and mechanical design at the microstructural level. My thesis is that the same architectural and energetic constraints that shape cells today also guided the evolution of the first cells and that the molecular scaffolds that support solid-phase biochemistry in modern cells represent living microfossils of past life forms. This concept emerged from the discovery that cells mechanically stabilize themselves using tensegrity architecture and that these same building rules guide hierarchical self-assembly at all size scales (Sci. Amer 278:48-57;1998). When combined with other fundamental design principles (e.g., energy minimization, topological constraints, structural hierarchies, autocatalytic sets, solid-state biochemistry), tensegrity provides a physical basis to explain how atomic and molecular elements progressively self-assembled to create hierarchical structures with increasingly complex functions, including living cells that can self-reproduce.

Early-Life State-of-Residence Characteristics and Later Life Hypertension, Diabetes, and Ischemic Heart Disease.

PubMed

Rehkopf, David H; Eisen, Ellen A; Modrek, Sepideh; Mokyr Horner, Elizabeth; Goldstein, Benjamin; Costello, Sadie; Cantley, Linda F; Slade, Martin D; Cullen, Mark R

2015-08-01

We examined how state characteristics in early life are associated with individual chronic disease later in life. We assessed early-life state of residence using the first 3 digits of social security numbers from blue- and white-collar workers from a US manufacturing company. Longitudinal data were available from 1997 to 2012, with 305 936 person-years of observation. Disease was assessed using medical claims. We modeled associations using pooled logistic regression with inverse probability of censoring weights. We found small but statistically significant associations between early-state-of-residence characteristics and later life hypertension, diabetes, and ischemic heart disease. The most consistent associations were with income inequality, percentage non-White, and education. These associations were similar after statistically controlling for individual socioeconomic and demographic characteristics and current state characteristics. Characteristics of the state in which an individual lives early in life are associated with prevalence of chronic disease later in life, with a strength of association equivalent to genetic associations found for these same health outcomes.

Marine origin of retroviruses in the early Palaeozoic Era

NASA Astrophysics Data System (ADS)

Aiewsakun, Pakorn; Katzourakis, Aris

2017-01-01

Very little is known about the ancient origin of retroviruses, but owing to the discovery of their ancient endogenous viral counterparts, their early history is beginning to unfold. Here we report 36 lineages of basal amphibian and fish foamy-like endogenous retroviruses (FLERVs). Phylogenetic analyses reveal that ray-finned fish FLERVs exhibit an overall co-speciation pattern with their hosts, while amphibian FLERVs might not. We also observe several possible ancient viral cross-class transmissions, involving lobe-finned fish, shark and frog FLERVs. Sequence examination and analyses reveal two major lineages of ray-finned fish FLERVs, one of which had gained two novel accessory genes within their extraordinarily large genomes. Our phylogenetic analyses suggest that this major retroviral lineage, and therefore retroviruses as a whole, have an ancient marine origin and originated together with, if not before, their jawed vertebrate hosts >450 million years ago in the Ordovician period, early Palaeozoic Era.

The Origin of Dust in the Early Universe

NASA Technical Reports Server (NTRS)

Dwek, Eli

2011-01-01

In this talk I will describe the origin of dust in the early universe. I will be presenting observations of the spectral energy distribution of the galaxy J1148+5251, and present estimates of the dust mass in this high redshift (z=6.4) object. I will then discuss the origin of this dust, and the role of SN and AGB stars as dust sources, and the effect of SNRs on the destruction of dust in the interstellar medium of this galaxy.

The Origin of Dust in the Early Universe

NASA Technical Reports Server (NTRS)

Dwek, Eliahu

2010-01-01

In this talk I will describe the origin of dust in the early universe. I will be presenting observations of the spectral energy distribution of the galaxy J1148+5251, and present estimates of the dust mass in this high redshift (z=6.4) object. I will then discuss the origin of this dust, and the role of SN and AGB stars as dust sources, and the effect of SNRs on the destruction of dust in the interstellar medium of this galaxy.

Sex differences in the consequences of early-life exposure to epidemiological stress--a life-history approach.

PubMed

Störmer, Charlotte

2011-01-01

Exposure to infectious disease in early life has been suggested to have a negative effect on later-life survival,possibly through the induction of inflammatory responses. Although a life-course perspective emphasizes the importance of both survival and reproduction for individual fitness, to date, no studies have investigated whether early-life exposure to infectious disease has an impact on reproduction as it has been suggested for later survival. To address this question, I have used family reconstitution data from a historical (18th and 19th century) human population in the Krummhörn (Germany) comparing survival and reproduction between an exposed and a non-exposed group. The exposed group comprised those exposed to a high-infectious disease load during prenatal and early postnatal development. The results show a marked sex difference in the impact of early-life exposure to infectious disease. Exposed females show no effect on their life expectancy but significantly reduced fertility (number of children). For exposed males, however, the effect on survival is opponent over time: mortality is increased during childhood but decreased in late adulthood. Above that, exposed males reproduce earlier and have a smaller proportion of surviving children. This study does not support former studies indicating a negative association between early-life disease load and later survival. I argue that due to differences in male and female life strategies, males in general are more vulnerable especially early in life. Hence, adverse environmental conditions may have a stronger effect on male survivability and reproductive performance.

Early life adversity potentiates the effects of later life stress on cumulative physiological dysregulation.

PubMed

Dich, Nadya; Hansen, Åse Marie; Avlund, Kirsten; Lund, Rikke; Mortensen, Erik Lykke; Bruunsgaard, Helle; Rod, Naja Hulvej

2015-01-01

Previous research indicates that early life adversity may heighten stress reactivity and impair mechanisms for adaptive coping, suggesting that experience of stress in early life may also potentiate adults' physiological vulnerability to stress in later life. The study tested this hypothesis by investigating whether the experience of stressful events and circumstances (SEC) in childhood or adolescence amplified the effect of adulthood SEC on physiological dysregulation (allostatic load, AL) in later midlife. Observational data were used in the present study. Physiological functioning was measured in later midlife (participants' age ranged from 49 to 63 years). Both childhood/adolescence and adulthood SEC were reported retrospectively on the same occasion. Participants were 5309 Danish men and women from Copenhagen Aging and Midlife Biobank (CAMB). SEC included socioeconomic and family factors. The AL index was based on nine cardiovascular, metabolic, and immune biomarkers. Experience of SEC in both early life and adulthood independently predicted higher AL. In men, experience of SEC in early life also potentiated the effect of SEC in adulthood on AL. The results provide further insight into the mechanisms behind the "biological embedding" of childhood stress.

The expression of human natural killer cell receptors in early life.

PubMed

Sundström, Y; Nilsson, C; Lilja, G; Kärre, K; Troye-Blomberg, M; Berg, L

2007-01-01

Natural killer (NK) cells play an important role in tumour immunosurveillance and the early defence against viral infections. Recognition of altered cells (i.e. infected- or tumour-cells) is achieved through a multiple receptor recognition strategy which gives the NK cells inhibitory or activating signals depending on the ligands present on the target cell. NK cells originate from the bone marrow where they develop and proliferate. However, further maturation processes and homeostasis of NK cells in peripheral blood are not well understood. To determine the proportions of cells and the expression of NK cell receptors, mononuclear cells from children at three time points during early childhood were compared, i.e. cord blood (CB), 2 and 5 years of age. The proportion of NK cells was high in CB, but the interferon-gamma (IFN-gamma) production low compared to later in life. In contrast, the proportion of T cells was low in CB. This may indicate a deviation of the regulatory function of NK cells in CB compared to later in life, implying an importance of innate immunity in early life before the adaptive immune system matures. Additionally, we found that the proportion of LIR-1(+) NK cells increased with increasing age while CD94(+)NKG2C(-) (NKG2A(+)) NK cells and the level of expression of NKG2D, NKp30 and NKp46 decreased with age. These age related changes in NK cell populations defined by the expression of activating and inhibitory receptors may be the result of pathogen exposure and/or a continuation of the maturation process that begins in the bone marrow.

The Big Bang, Superstring Theory and the origin of life on the Earth.

PubMed

Trevors, J T

2006-03-01

This article examines the origin of life on Earth and its connection to the Superstring Theory, that attempts to explain all phenomena in the universe (Theory of Everything) and unify the four known forces and relativity and quantum theory. The four forces of gravity, electro-magnetism, strong and weak nuclear were all present and necessary for the origin of life on the Earth. It was the separation of the unified force into four singular forces that allowed the origin of life.

Life's Late Digital Revolution and Why It Matters for the Study of the Origins of Life.

PubMed

Baum, David A; Lehman, Niles

2017-08-25

The information contained in life exists in two forms, analog and digital. Analog information is manifest mainly in the differing concentrations of chemicals that get passed from generation to generation and can vary from cell to cell. Digital information is encoded in linear polymers such as DNA and RNA, whose side chains come in discrete chemical forms. Here, we argue that the analog form of information preceded the digital. Acceptance of this dichotomy, and this progression, can help direct future studies on how life originated and initially complexified on the primordial Earth, as well as expected trajectories for other, independent origins of complex life.

Commentary: On the Importance of Early Life Cognitive Abilities in Shaping Later Life Outcomes.

PubMed

Hofer, Scott M; Clouston, Sean

2014-01-01

Early life cognitive ability is likely to be dynamically related to life course factors including educational attainment, occupational outcomes, health behaviors, activities, health, and subsequent cognitive health. Disentangling the selective and causal processes contributing to cognitive functioning across the lifespan is challenging and requires long-term investments in longitudinal data. We discuss results from several analyses using data from the Individual Development and Adaptation longitudinal research program (Bergman, 2000; Magnusson, 1988) that provide fresh insights into the relation of early life cognition, particularly high levels of cognitive capabilities, to educational achievement, emotional adjustment, and career success. These papers and the longitudinal data provide a remarkable window into the development and impacts of cognition, and high cognitive functioning, on a variety of important life outcomes that we hope will continue to inform us about additional outcomes in middle life, transition to retirement, and cognition and health in later years and to robustly examine how the early years matter across the whole lifespan.

Life Detection on the Early Earth

NASA Technical Reports Server (NTRS)

Runnegar, B.

2004-01-01

Finding evidence for first the existence, and then the nature of life on the early Earth or early Mars requires both the recognition of subtle biosignatures and the elimination of false positives. The history of the search for fossils in increasingly older Precambrian strata illustrates these difficulties very clearly, and new observational and theoretical approaches are both needed and being developed. At the microscopic level of investigation, three-dimensional morphological characterization coupled with in situ chemical (isotopic, elemental, structural) analysis is the desirable first step. Geological context is paramount, as has been demonstrated by the controversies over AH84001, the Greenland graphites, and the Apex chert microfossils . At larger scales, the nature of sedimentary bedforms and the structures they display becomes crucial, and here the methods of condensed matter physics prove most useful in discriminating between biological and non-biological constructions. Ultimately, a combination of geochemical, morphological, and contextural evidence may be required for certain life detection on the early Earth or elsewhere.

Early Life Conditions, Adverse Life Events, and Chewing Ability at Middle and Later Adulthood

PubMed Central

Watt, Richard G.; Tsakos, Georgios

2014-01-01

Objectives. We sought to determine the extent to which early life conditions and adverse life events impact chewing ability in middle and later adulthood. Methods. Secondary analyses were conducted based on data from waves 2 and 3 of the Survey of Health, Ageing, and Retirement in Europe (SHARE), collected in the years 2006 to 2009 and encompassing information on current chewing ability and the life history of persons aged 50 years or older from 13 European countries. Logistic regression models were estimated with sequential inclusion of explanatory variables representing living conditions in childhood and adverse life events. Results. After controlling for current determinants of chewing ability at age 50 years or older, certain childhood and later life course socioeconomic, behavioral, and cognitive factors became evident as correlates of chewing ability at age 50 years or older. Specifically, childhood financial hardship was identified as an early life predictor of chewing ability at age 50 years or older (odds ratio = 1.58; 95% confidence interval = 1.22, 2.06). Conclusions. Findings suggest a potential enduring impact of early life conditions and adverse life events on oral health in middle and later adulthood and are relevant for public health decision-makers who design strategies for optimal oral health. PMID:24625140

Asperger syndrome and "non-verbal learning problems" in a longitudinal perspective: neuropsychological and social adaptive outcome in early adult life.

PubMed

Hagberg, Bibbi S; Nydén, Agneta; Cederlund, Mats; Gillberg, Christopher

2013-12-15

Co-existence of Asperger syndrome (AS) and non-verbal learning disability (NLD) has been proposed based on the observation that people with AS tend to have significantly higher verbal than performance IQ (VIQ > PIQ by ≥ 15 points), one of the core features of NLD. In the present study we examined neuropsychological and social adaptive profiles with "non-verbal learning problems" associated with NLD in a group of individuals with AS followed from childhood into early adult life. The group was divided into three subgroups: (i) persistent NLD (P-NLD), i.e. NLD (VIQ > PIQ) both in childhood and early adulthood occasions, (ii) childhood NLD (CO-NLD), i.e. NLD (VIQ > PIQ) only at original diagnosis, or (iii) No NLD (VIQ > PIQ) ever (NO-NLD). All three subgroups were followed prospectively from childhood into adolescence and young adult life. One in four to one in five of the whole group of males with AS had P-NLD. The P-NLD subgroup had poorer neuropsychological outcome in early adult life than did those with CO-NLD and those with NO-NLD. There were no unequivocal markers in early childhood that predicted subgroup status in early adult life, but early motor delay and a history of early speech-language problems tended to be associated with P-NLD. © 2013 Elsevier Ireland Ltd. All rights reserved.

Astrobiology: exploring the origins, evolution, and distribution of life in the Universe.

PubMed

Des Marais, D J; Walter, M R

1999-01-01

The search for the origins of life and its presence beyond Earth is strengthened by new technology and by evidence that life tolerates extreme conditions and that planets are widespread. Astrobiologists learn how planets develop and maintain habitable conditions. They combine biological and information sciences to decipher the origins of life. They examine how biota, particularly microorganisms, evolve, at scales from the molecular to the biosphere level, including interactions with long-term planetary changes. Astrobiologists learn how to recognize the morphological, chemical, and spectroscopic signatures of life in order to explore both extraterrestrial samples and electromagnetic spectra reflected from extrasolar planets.

Astrobiology: exploring the origins, evolution, and distribution of life in the Universe

NASA Technical Reports Server (NTRS)

Des Marais, D. J.; Walter, M. R.

1999-01-01

The search for the origins of life and its presence beyond Earth is strengthened by new technology and by evidence that life tolerates extreme conditions and that planets are widespread. Astrobiologists learn how planets develop and maintain habitable conditions. They combine biological and information sciences to decipher the origins of life. They examine how biota, particularly microorganisms, evolve, at scales from the molecular to the biosphere level, including interactions with long-term planetary changes. Astrobiologists learn how to recognize the morphological, chemical, and spectroscopic signatures of life in order to explore both extraterrestrial samples and electromagnetic spectra reflected from extrasolar planets.

The Origin of Life from the Astrophysical Point of View

NASA Astrophysics Data System (ADS)

Yeghikyan, Ararat

2017-11-01

Тhe problem of the origin of life is discussed from the astrophysical point of view. Most biologists and geologists up to the present time believe that Life was originated on the Earth in some initial natural chemical pre-reactors, where a mixture of water, ammonia, methane containing species and some other substances, under the influence of an energy source like, e.g. lightning, turned into quite complex compounds such as amino acids and complex hydrocarbons. In fact, under conditions of the primordial Earth, it is not possible to obtain such pre-biological molecules by a-bio-chemical methods, as discussed in this lecture. Instead, an astrophysical view of the problem of the origin of life on the Earth is proposed and it is recalled that the biological evolution on the Earth was preceded by the chemical evolution of complex chemical compounds, mostly under extraterrestrial conditions, where it is only possible to form optically active amino acids, sugars and hydrocarbon is necessary for constructing the first pre-biomolecules .

Accounting Early for Life Long Learning: The AcE Project.

ERIC Educational Resources Information Center

University Coll. Worcester (England). Centre for Research in Early Childhood Education.

Building upon the work of the Effective Early Learning (EEL) Project in raising the quality of early learning for young children in the United Kingdom, the 3-year Accounting Early for Life Long Learning Project (AcE Project) focuses on enhancing in 3- to 6-year-olds those attitudes and dispositions that are important to life-long learning. This…

Fragmentation and Unpredictability of Early-Life Experience in Mental Disorders

PubMed Central

Baram, Tallie Z.; Solodkin, Ana; Davis, Elysia P.; Stern, Hal; Obenaus, Andre; Sandman, Curt A.; Small, Steven L.

2012-01-01

Maternal sensory signals in early life play a crucial role in programming the structure and function of the developing brain, promoting vulnerability or resilience to emotional and cognitive disorders. In rodent models of early-life stress, fragmentation and unpredictability of maternally derived sensory signals provoke persistent cognitive and emotional dysfunction in offspring. Similar variability and inconsistency of maternal signals during both gestation and early postnatal human life may influence development of emotional and cognitive functions, including those that underlie later depression and anxiety. PMID:22885631

On the origin of synthetic life: attribution of output to a particular algorithm

NASA Astrophysics Data System (ADS)

Yampolskiy, Roman V.

2017-01-01

With unprecedented advances in genetic engineering we are starting to see progressively more original examples of synthetic life. As such organisms become more common it is desirable to gain an ability to distinguish between natural and artificial life forms. In this paper, we address this challenge as a generalized version of Darwin’s original problem, which he so brilliantly described in On the Origin of Species. After formalizing the problem of determining the samples’ origin, we demonstrate that the problem is in fact unsolvable. In the general case, if computational resources of considered originator algorithms have not been limited and priors for such algorithms are known to be equal, both explanations are equality likely. Our results should attract attention of astrobiologists and scientists interested in developing a more complete theory of life, as well as of AI-Safety researchers.

Planetary Sources for Reducing Sulfur Compounds for Cyanosulfidic Origins of Life Chemistry

NASA Astrophysics Data System (ADS)

Ranjan, S.; Todd, Z. R.; Sutherland, J.; Sasselov, D. D.

2017-12-01

A key challenge in origin-of-life studies is understanding the chemistry that lead to the origin of the key biomolecules of life, such as the components of nucleic acids, sugars, lipids, and proteins. Prebiotic reaction networks based upon reductive homologation of nitriles (e.g., Patel et al. 2015), are building a tantalizing picture of sustained abiotic synthesis of activated ribonucleotides, amino acids and lipid precursors under environmental conditions thought to have been available on early Earth. Sulfidic anions in aqueous solution (e.g., HS-, HSO3-) under near-UV irradiation play important roles in these chemical pathways. However, the sources and availability of these anions on early Earth have not yet been quantitatively constrained. Here, we evaluate the potential for the atmosphere to serve as a source of sulfidic anions, via dissolution of volcanically-outgassed SO2 and H2S into water reservoirs. We combine photochemical modeling from the literature (Hu et al. 2013) with equilibrium chemistry calculations to place constraints on the partial pressures of SO2 and H2S required to reach the elevated concentrations of sulfidic anions (≥1 μM) thought to be necessary for prebiotic chemistry. We find that micromolar levels of SO2-derived anions (HSO3-, SO3(2-)) are possible through simple exposure of aqueous reservoirs like shallow lakes to the atmosphere, assuming total sulfur emission flux comparable to today. Millimolar levels of these compounds are available during the epochs of elevated volcanism, due to elevated sulfur emission flux. Radiative transfer modeling suggests the atmospheric sulfur will not block the near-UV radiation also required for the cyanosulfidic chemistry. However, H2S-derived anions (e.g., HS-) reach only sub-micromolar levels from atmospheric sources, meaning that prebiotic chemistry invoking such molecules must invoke specialized, local sources. Prebiotic chemistry invoking SO2-derived anions may be considered more robust than

Are comets connected to the origin of life

NASA Technical Reports Server (NTRS)

Delsemme, A. H.

1981-01-01

Possible connections between comets and the origin of life on earth are discussed. The orbital evolution of comets and their origin are considered within a framework for the origin of the solar system, with particular attention given to the origin of the biosphere, and the origin of the Oort cloud. Evidence suggesting that cometary nuclei are undifferentiated throughout is considered, and a model of the average composition of a mean new comet is obtained from observational data which is similar to that of an interstellar frost. The chemistry of the model composition giving rise to the species observed in cometary spectra is considered, as well as the relations of cometary to cosmic abundances of oxygen, carbon and sulfur. The characteristics of possible sites for prebiotic chemistry, including interstellar clouds, the protosolar nebula, comets in the Oort cloud, periodic comets and the primitive earth, are examined, and a possible role of comets in bringing the interstellar prebiotic chemistry to earth is suggested.

Effect of Early- and Adult-Life Socioeconomic Circumstances on Physical Inactivity.

PubMed

Cheval, Boris; Sieber, Stefan; Guessous, Idris; Orsholits, Dan; Courvoisier, Delphine S; Kliegel, Matthias; Stringhini, Silvia; Swinnen, Stephan P; Burton-Jeangros, Claudine; Cullati, Stéphane; Boisgontier, Matthieu P

2018-03-01

This study aimed to investigate the associations between early- and adult-life socioeconomic circumstances and physical inactivity (level and evolution) in aging using large-scale longitudinal data. This study used the Survey of Health Ageing and Retirement in Europe, a 10-yr population-based cohort study with repeated measurements in five waves, every 2 yr between 2004 and 2013. Self-reported physical inactivity (waves 1, 2, 4, and 5), household income (waves 1, 2, 4, and 5), educational attainment (wave of the first measurement occasion), and early-life socioeconomic circumstance (wave 3) were collected in 22,846 individuals 50 to 95 yr of age. Risk of physical inactivity was increased for women with the most disadvantaged early-life socioeconomic circumstances (odds ratio [OR], 1.49; 95% confidence interval [CI], 1.20-1.86). With aging, the risk of physical inactivity increased for both sexes and was strongest for those with the most disadvantaged early-life socioeconomic circumstances (OR, 1.04 (95% CI, 1.02-1.06) for women; OR, 1.02 (95% CI, 1.00-1.05) for men), with the former effect being more robust than the latter one. The association between early-life socioeconomic circumstances and physical inactivity was mediated by adult-life socioeconomic circumstances, with education being the strongest mediator. Early-life socioeconomic circumstances predicted high levels of physical inactivity at older ages, but this effect was mediated by socioeconomic indicators in adult life. This finding has implications for public health policies, which should continue to promote education to reduce physical inactivity in people at older ages and to ensure optimal healthy aging trajectories, especially among women with disadvantaged early-life socioeconomic circumstances.

Life on Mars

NASA Technical Reports Server (NTRS)

McKay, Christopher P.; Cuzzi, Jeffrey (Technical Monitor)

1996-01-01

Although the Viking results may indicate that Mars has no life today, the possibility exists that Mars may hold the best record of the events that led to the origin of life. There is direct geomorphological evidence that in the past Mars had large amounts of liquid water on its surface. Atmospheric models would suggest that this early period of hydrological activity was due to the presence of a thick atmosphere and the resulting warmer temperatures. From a biological perspective the existence of liquid water, by itself motivates the question of the origin of life on Mars. From studies of the Earth's earliest biosphere we know that by 3.5 Gyr. ago, life had originated on Earth and reached a fair degree of biological sophistication. Surface activity and erosion on Earth make it difficult to trace the history of life before the 3.5 Gyr timeframe. If Mars did maintain a clement environment for longer than it took for life to originate on Earth, then the question of the origin of life on Mars follows naturally.

Jigsaw model of the origin of life

NASA Astrophysics Data System (ADS)

McGowan, John F.

2002-02-01

It is suggested that life originated in a three-step process referred to as the jigsaw model. RNA, proteins, or similar organic molecules polymerized in a dehydrated carbon-rich environment, on surfaces in a carbon-rich environment, or in another environment where polymerization occurs. These polymers subsequently entered an aqueous environment where they folded into compact structures. It is argued that the folding of randomly generated polymers such as RNA or proteins in water tends to partition the folded polymer into domains with hydrophobic cores and matching shapes to minimize energy. In the aqueous environment hydrolysis or other reactions fragmented the compact structures into two or more matching molecules, occasionally producing simple living systems, also knows as autocatalytic sets of molecules. It is argued that the hydrolysis of folded polymers such as RNA or proteins is not random. The hydrophobic cores of the domains are rarely bisected due to the energy requirements in water. Hydrolysis preferentially fragments the folded polymers into pieces with complementary structures and chemical affinities. Thus the probability of producing a system of matched, interacting molecules in prebiotic chemistry is much higher than usually estimated. Environments where this process may occur are identified. For example, the jigsaw model suggests life may have originated at a seep or carbonaceous fluids beneath the ocean. The polymerization occurred beneath the sea floor. The folding and fragmentation occurred in the ocean. The implications of this hypothesis for seeking life or prebiotic chemistry in the Solar System are explored.

Early childhood growth failure and the developmental origins of adult disease: Do enteric infections and malnutrition increase risk for the metabolic syndrome?

PubMed Central

DeBoer, Mark D.; Lima, Aldo A. M.; Oría, Reinaldo B.; Scharf, Rebecca J.; Moore, Sean R.; Luna, Max A.; Guerrant, Richard L.

2012-01-01

Hypotheses regarding the developmental origins of health and disease postulate that developing fetuses–and potentially young children—undergo adaptive epigenetic changes with longstanding effects on metabolism and other processes. Ongoing research explores whether these adaptations occur during early life following malnutrition. In the developing world there remains a high degree of nutritional stunting—linear growth failure due to inadequate calories that may be exacerbated by inflammation from ongoing infections. In areas with poor sanitation children experience vicious cycles of enteric infections and malnutrition, resulting in poor nutrient absorption from intestinal mucosa changes now termed “environmental enteropathy.” Emerging evidence links early childhood diarrhea and/or growth failure with increased CVD risk factors in later life, including dyslipidemia, hypertension and glucose intolerance. The mechanisms for these associations remain poorly understood and may relate to epigenetic responses to poor nutrition, increased inflammation or both. Given increases in CVD in developing areas of the world, associations between childhood malnutrition, early life infections and increased CVD risk factors underscore further reasons to improve nutrition and infection-related outcomes for young children worldwide. PMID:23110643

Development of the Life Story in Early Adolescence

ERIC Educational Resources Information Center

Steiner, Kristina L.; Pillemer, David B.

2018-01-01

Life span developmental psychology proposes that the ability to create a coherent life narrative does not develop until early adolescence. Using a novel methodology, 10-, 12-, and 14-year-old participants were asked to tell their life stories aloud to a researcher. Later, participants separated their transcribed narratives into self-identified…

Darwin and the origin of life: public versus private science.

PubMed

Strick, James E

2009-12-01

In the first twenty years after the publication of Darwin's On the Origin of Species, an intense debate took place within the ranks of Darwin's supporters over exactly what his theory implied about the means by which the original living organism formed on Earth. Many supporters of evolutionary science also supported the doctrine of spontaneous generation: life forming from nonliving material not just once but many times up to the present day. Darwin was ambivalent on this topic. He feared its explosive potential to drive away liberal-minded Christians who might otherwise be supporters. His ambivalent wording created still more confusion, both among friends and foes, about what Darwin actually believed about the origin of life. A famous lecture by Thomas H. Huxley in 1870 set forth what later became the 'party line' Darwinian position on the subject.

Amino Acids in Asteroids and Comets: Implications for the Origin of Life on Earth and Possibly Elsewhere

NASA Technical Reports Server (NTRS)

Glavin, Daniel

2012-01-01

Meteorites provide a record of the chemical processes that occurred in the early solar system before life began on Earth. The delivery of organic matter by asteroids, comets, and their fragments to the Earth and other planetary bodies in our solar system could have been an important source of the prebiotic organic inventory needed for the emergence of life. Amino acids are essential components of proteins and enzymes in life on Earth and these prebiotic organic compounds have been detected in a wide variety of carbon-rich meteorites, the majority of which have been determined to be extraterrestrial in origin. In addition, many amino acids are structurally chiral (they possess handedness) and with a few very rare exceptions, only left handed (L) amino acids are found in biology, while all known abiotic syntheses of amino acids result in equal mixtures of left and right handed (LD) amino acids. The discovery of a significant left handed amino acid imbalance of up to 20% in several different carbonaceous meteorites, could point toward a possible prebiotic contribution to the origin of biological homochirality by the exogenous delivery of extraterrestrial organic material to the early Earth. In this talk, I will focus on recent state-of-the-art measurements of the distribution, chirality, and isotopic composition of amino acids in meteorites and cometary samples carried out at the Goddard Astrobiology Analytical Laboratory. Results from the analyses of a variety of Antarctic meteorites, samples from comet Wild 2 returned by the STARDUST mission, and meteorite fragments of asteroid 2008 TC3 called Almahata Sitta recovered from northern Sudan will be discussed

Impact Chemistry and the Origin of Life

NASA Astrophysics Data System (ADS)

Melosh, H. J.; Pasek, M.

2012-12-01

Most discussions of global environmental effects of large impacts focus on changes deleterious to extant life. However, impacts may also produce changes that enhance or even create conditions beneficial to the origin of life. Many other authors have discussed impact delivery of organic molecules, and some have shown the shock synthesis of prebiotic molecules such as amino acids during impact. Our past work on the chemistry of impacts demonstrated that strong chemical reduction occurs in impact melt ejecta (spherules and melt droplets; tektites). Here we focus on the element phosphorus (P), whose role is crucial in biology as the backbone of DNA and RNA, and in metabolic biochemical energy transfer. Pasek previously showed that reduced P readily enters into interesting biological compounds with organic molecules in aqueous solution, and that these reduced P compounds may generate structures similar to sugar phosphates, which are critical to life as we know it. In this talk we argue that impact reduction of P transforms terrestrial and meteoritic phosphates bearing an oxidation state of +5 to the lower redox states of +3 (phosphites) and 0 as an alloy with metal (phosphides). We base this argument on studies of fulgurites—glasses formed by cloud-to-ground lightning—that bear phosphides and phosphites as major carriers of P. Fulgurite chemistry frequently parallels that of impact glasses. Additionally, thermodynamic calculations show that separation of an O-rich vapor from a melt readily results in the transformation of phosphate to phosphites and metal phosphides. These results are confirmed by the presence of metal phosphides within tektites. The impact reduction of phosphates followed by global dispersal of reduced P in the form of glassy droplets likely played a major role in the origin of life on Earth and perhaps on other young planets.

Mineral-organic interfacial processes: potential roles in the origins of life.

PubMed

Cleaves, H James; Michalkova Scott, Andrea; Hill, Frances C; Leszczynski, Jerzy; Sahai, Nita; Hazen, Robert

2012-08-21

Life is believed to have originated on Earth ∼4.4-3.5 Ga ago, via processes in which organic compounds supplied by the environment self-organized, in some geochemical environmental niches, into systems capable of replication with hereditary mutation. This process is generally supposed to have occurred in an aqueous environment and, likely, in the presence of minerals. Mineral surfaces present rich opportunities for heterogeneous catalysis and concentration which may have significantly altered and directed the process of prebiotic organic complexification leading to life. We review here general concepts in prebiotic mineral-organic interfacial processes, as well as recent advances in the study of mineral surface-organic interactions of potential relevance to understanding the origin of life.

Early-Life Stress, HPA Axis Adaptation, and Mechanisms Contributing to Later Health Outcomes

PubMed Central

Maniam, Jayanthi; Antoniadis, Christopher; Morris, Margaret J.

2014-01-01

Stress activates the hypothalamic–pituitary–adrenal (HPA) axis, which then modulates the degree of adaptation and response to a later stressor. It is known that early-life stress can impact on later health but less is known about how early-life stress impairs HPA axis activity, contributing to maladaptation of the stress–response system. Early-life stress exposure (either prenatally or in the early postnatal period) can impact developmental pathways resulting in lasting structural and regulatory changes that predispose to adulthood disease. Epidemiological, clinical, and experimental studies have demonstrated that early-life stress produces long term hyper-responsiveness to stress with exaggerated circulating glucocorticoids, and enhanced anxiety and depression-like behaviors. Recently, evidence has emerged on early-life stress-induced metabolic derangements, for example hyperinsulinemia and altered insulin sensitivity on exposure to a high energy diet later in life. This draws our attention to the contribution of later environment to disease vulnerability. Early-life stress can alter the expression of genes in peripheral tissues, such as the glucocorticoid receptor and 11-beta hydroxysteroid dehydrogenase (11β-HSD1). We propose that interactions between altered HPA axis activity and liver 11β-HSD1 modulates both tissue and circulating glucocorticoid availability, with adverse metabolic consequences. This review discusses the potential mechanisms underlying early-life stress-induced maladaptation of the HPA axis, and its subsequent effects on energy utilization and expenditure. The effects of positive later environments as a means of ameliorating early-life stress-induced health deficits, and proposed mechanisms underpinning the interaction between early-life stress and subsequent detrimental environmental exposures on metabolic risk will be outlined. Limitations in current methodology linking early-life stress and later health outcomes will also be

Life Origination and Development Hydrate theory (LOH-Theory): new approaches to the problems of the optimal nutrition and life prolongation

NASA Astrophysics Data System (ADS)

Kadyshevich, E. A.; Ostrovskii, V. E.

2014-04-01

Life Origination Hydrate Theory (LOH-Theory) and Mitosis and Replication Hydrate Theory (MRHTheory), both grounded on the notion of honeycomb gas-hydrate structures formation/destruction as the physicochemical phenomenon governing the DNA origination and replication, allow new approaches to the optimal nutrition and life prolongation problems.

The positive and negative consequences of stressors during early life.

PubMed

Monaghan, Pat; Haussmann, Mark F

2015-11-01

We discuss the long-term effects of stress exposure in pre- and early postnal life. We present an evolutionary framework within which such effects can be viewed, and describe how the outcomes might vary with species life histories. We focus on stressors that induce increases in glucocorticoid hormones and discuss the advantages of an experimental approach. We describe a number of studies demonstrating how exposure to these hormones in early life can influence stress responsiveness and have substantial long-term, negative consequences for adult longevity. We also describe how early life exposure to mild levels of stressors can have beneficial effects on resilience to stress in later life, and discuss how the balance of costs and benefits is likely dependent on the nature of the adult environment. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

IGF-1 deficiency in a critical period early in life influences the vascular aging phenotype in mice by altering miRNA-mediated post-transcriptional gene regulation: implications for the developmental origins of health and disease hypothesis.

PubMed

Tarantini, Stefano; Giles, Cory B; Wren, Jonathan D; Ashpole, Nicole M; Valcarcel-Ares, M Noa; Wei, Jeanne Y; Sonntag, William E; Ungvari, Zoltan; Csiszar, Anna

2016-08-01

Epidemiological findings support the concept of Developmental Origins of Health and Disease, suggesting that early-life hormonal influences during a sensitive period of development have a fundamental impact on vascular health later in life. The endocrine changes that occur during development are highly conserved across mammalian species and include dramatic increases in circulating IGF-1 levels during adolescence. The present study was designed to characterize the effect of developmental IGF-1 deficiency on the vascular aging phenotype. To achieve that goal, early-onset endocrine IGF-1 deficiency was induced in mice by knockdown of IGF-1 in the liver using Cre-lox technology (Igf1 f/f mice crossed with mice expressing albumin-driven Cre recombinase). This model exhibits low-circulating IGF-1 levels during the peripubertal phase of development, which is critical for the biology of aging. Due to the emergence of miRNAs as important regulators of the vascular aging phenotype, the effect of early-life IGF-1 deficiency on miRNA expression profile in the aorta was examined in animals at 27 months of age. We found that developmental IGF-1 deficiency elicits persisting late-life changes in miRNA expression in the vasculature, which significantly differed from those in mice with adult-onset IGF-1 deficiency (TBG-Cre-AAV8-mediated knockdown of IGF-1 at 5 month of age in Igf1 f/f mice). Using a novel computational approach, we identified miRNA target genes that are co-expressed with IGF-1 and associate with aging and vascular pathophysiology. We found that among the predicted targets, the expression of multiple extracellular matrix-related genes, including collagen-encoding genes, were downregulated in mice with developmental IGF-1 deficiency. Collectively, IGF-1 deficiency during a critical period during early in life results in persistent changes in post-transcriptional miRNA-mediated control of genes critical targets for vascular health, which likely contribute to the

Second Symposium on Chemical Evolution and the Origin of Life

NASA Technical Reports Server (NTRS)

Devincenzi, D. L. (Editor); model. (Editor)

1986-01-01

Recent findings by NASA Exobiology investigators are reported. Scientific papers are presented in the following areas: cosmic evolution of biogenic compounds, prebiotic evolution (planetary and molecular), early evolution of life (biological and geochemical), evolution of advanced life, solar system exploration, and the Search for Extraterrestrial Intelligence (SETI).

Second Symposium on Chemical Evolution and the Origin of Life

DOE Office of Scientific and Technical Information (OSTI.GOV)

Devincenzi, D.L.; Dufour, P.A.

1986-05-01

Recent findings by NASA Exobiology investigators are reported. Scientific papers are presented in the following areas: cosmic evolution of biogenic compounds, prebiotic evolution (planetary and molecular), early evolution of life (biological and geochemical), evolution of advanced life, solar system exploration, and the Search for Extraterrestrial Intelligence (SETI).

Early Silurian Foraminifera from Gondwana - an early origin of the multichambered globothalamids?

NASA Astrophysics Data System (ADS)

Kaminski, Michael

2017-04-01

Early Silurian foraminifera until now have been regarded to consist of simple single-chambered monothalamids and two-chambered tubothalamids with an agglutinated wall. Although pseudo-multichambered agglutinated foraminifera first appeared in the mid-Ordovician (Kaminski et al. 2009), the origin of true multichambered forms was not believed to have taken place until the early or middle Devonian at the earliest (Holcová, 2002). New discoveries from the Lower Silurian Qusaiba Shale Member in Saudi Arabia point to an earlier origin of the multichambered globothalamid Foraminifera than the currently accepted estimate of 350 Ma (Pawlowski et al. 2003). The agglutinated foraminiferal genera Ammobaculites and Sculptobaculites have been recovered from dark graptolite-bearing claystones of Telychian age, from the transitional facies between the Qusaiba and Sharawa Members of the Qasim Formation at the type locality near Qusaiba town, Saudi Arabia. The multichambered lituolids occur as rare components in a foraminiferal assemblage consisting mostly of monothalamids. This new finding revises our understanding of the early evolution of the multichambered globothalamid foraminifera. The fossil record now shows that the globothalamids were already present in Gondwana by 435 m.y. Holcová, K. 2002. Silurian and Devonian foraminifers and other acid-resistant microfossils from the Barrandian area. Acta Musei Nationalis Pragae, Series B, Historia Naturalis, 58 (3-4), 83-140. Kaminski, M.A., Henderson, A.S., Cetean, C.G. & Waskowska-Oliwa, A. 2009. A new family of agglutinated foraminifera: the Ammolagenidae n.fam., and the evolution of multichambered tests. Micropaleontology, 55 (5), 487-494. Pawlowski, J., Holzmann, M., Berney, C., Fahrni, J.F., Gooday, Aj., Cedhagen, T., Habura, A., & Bowser, SS. 2003. The evolution of early Foraminifera. Proceedings of the National Academy of Sciences, 100 (20), 11494-11498

What Does "the RNA World" Mean to "the Origin of Life"?

PubMed

Ma, Wentao

2017-11-29

Corresponding to life's two distinct aspects: Darwinian evolution and self-sustainment, the origin of life should also split into two issues: the origin of Darwinian evolution and the arising of self-sustainment. Because the "self-sustainment" we concern about life should be the self-sustainment of a relevant system that is "defined" by its genetic information, the self-sustainment could not have arisen before the origin of Darwinian evolution, which was just marked by the emergence of genetic information. The logic behind the idea of the RNA world is not as tenable as it has been believed. That is, genetic molecules and functional molecules, even though not being the same material, could have emerged together in the beginning and launched the evolution-provided that the genetic molecules can "simply" code the functional molecules. However, due to these or those reasons, alternative scenarios are generally much less convincing than the RNA world. In particular, when considering the accumulating experimental evidence that is supporting a de novo origin of the RNA world, it seems now quite reasonable to believe that such a world may have just stood at the very beginning of life on the Earth. Therewith, we acquire a concrete scenario for our attempts to appreciate those fundamental issues that are involved in the origin of life. In the light of those possible scenes included in this scenario, Darwinian evolution may have originated at the molecular level, realized upon a functional RNA. When two or more functional RNAs emerged, for their efficient cooperation, there should have been a selective pressure for the emergence of protocells. But it was not until the appearance of the "unitary-protocell", which had all of its RNA genes linked into a chromosome, that Darwinian evolution made its full step towards the cellular level-no longer severely constrained by the low-grade evolution at the molecular level. Self-sustainment did not make sense before protocells emerged

Origin of microbial life: Nano- and molecular events, thermodynamics/entropy, quantum mechanisms and genetic instructions.

PubMed

Trevors, J T

2011-03-01

Currently, there are no agreed upon mechanisms and supporting evidence for the origin of the first microbial cells on the Earth. However, some hypotheses have been proposed with minimal supporting evidence and experimentation/observations. The approach taken in this article is that life originated at the nano- and molecular levels of biological organization, using quantum mechanic principles that became manifested as classical microbial cell(s), allowing the origin of microbial life on the Earth with a core or minimal, organic, genetic code containing the correct instructions for cell(s) for growth and division, in a micron dimension environment, with a local entropy range conducive to life (present about 4 billion years ago), and obeying the laws of thermodynamics. An integrated approach that explores all encompassing factors necessary for the origin of life, may bring forth plausible hypotheses (and mechanisms) with much needed supporting experimentation and observations for an origin of life theory. Copyright © 2010 Elsevier B.V. All rights reserved.

Precedents of perceived social support: personality and early life experiences.

PubMed

Kitamura, T; Kijima, N; Watanabe, K; Takezaki, Y; Tanaka, E

1999-12-01

In order to examine the effects of personality and early life experiences on perceived social support, a total of 97 young Japanese women were investigated. Current interpersonal relationships were measured by an interview modified from Henderson et al.'s Interview Schedule for Social Interaction (ISSI). Personality was measured by Cloninger et al.'s Temperament and Character Inventory. Early life experiences at home and outside of home were also identified in the interview. The number of sources of perceived support was correlated with self-directness, while satisfaction with perceived support was correlated with novelty seeking and with low harm avoidance. No early life experiences--early loss of a parent, perceived parenting, childhood abuse experiences, experiences of being bullied and/or other life events--showed significant correlations with the number or satisfaction of supportive people. The quantity and quality of perception of social support differ in their link to personality, and perceived social support may, to some extent, be explainable in terms of personality.

Linguistic ability in early life and cognitive function and Alzheimer's disease in late life. Findings from the Nun Study.

PubMed

Snowdon, D A; Kemper, S J; Mortimer, J A; Greiner, L H; Wekstein, D R; Markesbery, W R

1996-02-21

To determine if linguistic ability in early life is associated with cognitive function and Alzheimer's disease in late life. Two measures of linguistic ability in early life, idea density and grammatical complexity, were derived from autobiographies written at a mean age of 22 years. Approximately 58 years later, the women who wrote these autobiographies participated in an assessment of cognitive function, and those who subsequently died were evaluated neuropathologically. Convents in the United States participating in the Nun Study; primarily convents in the Milwaukee, Wis, area. Cognitive function was investigated in 93 participants who were aged 75 to 95 years at the time of their assessments, and Alzheimer's disease was investigated in the 14 participants who died at 79 to 96 years of age. Seven neuropsychological tests and neuropathologically confirmed Alzheimer's disease. Low idea density and low grammatical complexity in autobiographies written in early life were associated with low cognitive test scores in late life. Low idea density in early life had stronger and more consistent associations with poor cognitive function than did low grammatical complexity. Among the 14 sisters who died, neuropathologically confirmed Alzheimer's disease was present in all of those with low idea density in early life and in none of those with high idea density. Low linguistic ability in early life was a strong predictor of poor cognitive function and Alzheimer's disease in late life.

The "Origin-of-Life Reactor" and Reduction of CO2 by H2 in Inorganic Precipitates.

PubMed

Jackson, J Baz

2017-08-01

It has been suggested that inorganic membranes were forerunners of organic membranes at the origin of life. Such membranes, interposed between alkaline fluid in submarine vents and the more acidic Hadean ocean, were thought to house inorganic molecular machines. H + flowed down the pH gradient (ΔpH) from ocean to vent through the molecular machines to drive metabolic reactions for early life. A set of experiments was performed by Herschy et al. (J Mol Evol 79:213-227, 2014) who followed earlier work to construct inorganic precipitate membranes which, they argued, would be transected by a ΔpH. They supposed that inorganic molecular machines might assemble by chance in the precipitate membranes, and be capable of using the ΔpH to drive unfavourable reduction of CO 2 by H 2 to formate and formaldehyde. Indeed, these workers detected both of these compounds in their origin-of-life reaction vessel and contend this was proof of principle for their hypothesis. However, it is shown here by a straightforward calculation that the formate produced was only that which reached on approach to equilibrium without any driving force from ΔpH. We conclude that the reaction was facilitated by isotropic catalysts in the precipitate membrane but not by an anisotropic ΔpH-driven molecular machine.

The origin of life is a spatially localized stochastic transition

PubMed Central

2012-01-01

Background Life depends on biopolymer sequences as catalysts and as genetic material. A key step in the Origin of Life is the emergence of an autocatalytic system of biopolymers. Here we study computational models that address the way a living autocatalytic system could have emerged from a non-living chemical system, as envisaged in the RNA World hypothesis. Results We consider (i) a chemical reaction system describing RNA polymerization, and (ii) a simple model of catalytic replicators that we call the Two’s Company model. Both systems have two stable states: a non-living state, characterized by a slow spontaneous rate of RNA synthesis, and a living state, characterized by rapid autocatalytic RNA synthesis. The origin of life is a transition between these two stable states. The transition is driven by stochastic concentration fluctuations involving relatively small numbers of molecules in a localized region of space. These models are simulated on a two-dimensional lattice in which reactions occur locally on single sites and diffusion occurs by hopping of molecules to neighbouring sites. Conclusions If diffusion is very rapid, the system is well-mixed. The transition to life becomes increasingly difficult as the lattice size is increased because the concentration fluctuations that drive the transition become relatively smaller when larger numbers of molecules are involved. In contrast, when diffusion occurs at a finite rate, concentration fluctuations are local. The transition to life occurs in one local region and then spreads across the rest of the surface. The transition becomes easier with larger lattice sizes because there are more independent regions in which it could occur. The key observations that apply to our models and to the real world are that the origin of life is a rare stochastic event that is localized in one region of space due to the limited rate of diffusion of the molecules involved and that the subsequent spread across the surface is

Early trace of life from 3.95 Ga sedimentary rocks in Labrador, Canada

NASA Astrophysics Data System (ADS)

Tashiro, Takayuki; Ishida, Akizumi; Hori, Masako; Igisu, Motoko; Koike, Mizuho; Méjean, Pauline; Takahata, Naoto; Sano, Yuji; Komiya, Tsuyoshi

2017-09-01

The vestiges of life in Eoarchean rocks have the potential to elucidate the origin of life. However, gathering evidence from many terrains is not always possible, and biogenic graphite has thus far been found only in the 3.7-3.8 Ga (gigayears ago) Isua supracrustal belt. Here we present the total organic carbon contents and carbon isotope values of graphite (δ13Corg) and carbonate (δ13Ccarb) in the oldest metasedimentary rocks from northern Labrador. Some pelitic rocks have low δ13Corg values of -28.2, comparable to the lowest value in younger rocks. The consistency between crystallization temperatures of the graphite and metamorphic temperature of the host rocks establishes that the graphite does not originate from later contamination. A clear correlation between the δ13Corg values and metamorphic grade indicates that variations in the δ13Corg values are due to metamorphism, and that the pre-metamorphic value was lower than the minimum value. We concluded that the large fractionation between the δ13Ccarb and δ13Corg values, up to 25‰, indicates the oldest evidence of organisms greater than 3.95 Ga. The discovery of the biogenic graphite enables geochemical study of the biogenic materials themselves, and will provide insight into early life not only on Earth but also on other planets.

Early trace of life from 3.95 Ga sedimentary rocks in Labrador, Canada.

PubMed

Tashiro, Takayuki; Ishida, Akizumi; Hori, Masako; Igisu, Motoko; Koike, Mizuho; Méjean, Pauline; Takahata, Naoto; Sano, Yuji; Komiya, Tsuyoshi

2017-09-27

The vestiges of life in Eoarchean rocks have the potential to elucidate the origin of life. However, gathering evidence from many terrains is not always possible, and biogenic graphite has thus far been found only in the 3.7-3.8 Ga (gigayears ago) Isua supracrustal belt. Here we present the total organic carbon contents and carbon isotope values of graphite (δ 13 C org ) and carbonate (δ 13 C carb ) in the oldest metasedimentary rocks from northern Labrador. Some pelitic rocks have low δ 13 C org values of -28.2, comparable to the lowest value in younger rocks. The consistency between crystallization temperatures of the graphite and metamorphic temperature of the host rocks establishes that the graphite does not originate from later contamination. A clear correlation between the δ 13 C org values and metamorphic grade indicates that variations in the δ 13 C org values are due to metamorphism, and that the pre-metamorphic value was lower than the minimum value. We concluded that the large fractionation between the δ 13 C carb and δ 13 C org values, up to 25‰, indicates the oldest evidence of organisms greater than 3.95 Ga. The discovery of the biogenic graphite enables geochemical study of the biogenic materials themselves, and will provide insight into early life not only on Earth but also on other planets.

Early-life gut microbiome and egg allergy.

PubMed

Fazlollahi, M; Chun, Y; Grishin, A; Wood, R A; Burks, A W; Dawson, P; Jones, S M; Leung, D Y M; Sampson, H A; Sicherer, S H; Bunyavanich, S

2018-07-01

Gut microbiota may play a role in egg allergy. We sought to examine the association between early-life gut microbiota and egg allergy. We studied 141 children with egg allergy and controls from the multicenter Consortium of Food Allergy Research study. At enrollment (age 3 to 16 months), fecal samples were collected, and clinical evaluation, egg-specific IgE measurement, and egg skin prick test were performed. Gut microbiome was profiled by 16S rRNA sequencing. Analyses for the primary outcome of egg allergy at enrollment, and the secondary outcomes of egg sensitization at enrollment and resolution of egg allergy by age 8 years, were performed using Quantitative Insights into Microbial Ecology, Phylogenetic Investigation of Communities by Reconstruction of Unobserved States, and Statistical Analysis of Metagenomic Profiles. Compared to controls, increased alpha diversity and distinct taxa (PERMANOVA P = 5.0 × 10 -4 ) characterized the early-life gut microbiome of children with egg allergy. Genera from the Lachnospiraceae, Streptococcaceae, and Leuconostocaceae families were differentially abundant in children with egg allergy. Predicted metagenome functional analyses showed differential purine metabolism by the gut microbiota of egg-allergic subjects (Kruskal-Wallis P adj  = 0.021). Greater gut microbiome diversity and genera from Lachnospiraceae and Ruminococcaceae were associated with egg sensitization (PERMANOVA P = 5.0 × 10 -4 ). Among those with egg allergy, there was no association between early-life gut microbiota and egg allergy resolution by age 8 years. The distinct early-life gut microbiota in egg-allergic and egg-sensitized children identified by our study may point to targets for preventive or therapeutic intervention. © 2018 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

Early life factors in the pathogenesis of osteoporosis.

PubMed

Winsloe, Chivon; Earl, Susie; Dennison, Elaine M; Cooper, Cyrus; Harvey, Nicholas C

2009-12-01

Osteoporosis is a major public health burden through associated fragility fractures. Bone mass, a composite of bone size and volumetric density, increases through early life and childhood to a peak in early adulthood. The peak bone mass attained is a strong predictor of future risk of osteoporosis. Evidence is accruing that environmental factors in utero and in early infancy may permanently modify the postnatal pattern of skeletal growth to peak and thus influence risk of osteoporosis in later life. This article describes the latest data in this exciting area of research, including novel epigenetic and translation work, which should help to elucidate the underlying mechanisms and give rise to potential public health interventions to reduce the burden of osteoporotic fracture in future generations.

40 CFR 797.1600 - Fish early life stage toxicity test.

Code of Federal Regulations, 2014 CFR

2014-07-01

... the test solution concentrations. The test terminates following 60 days of post-hatch exposure (for an... 40 Protection of Environment 32 2014-07-01 2014-07-01 false Fish early life stage toxicity test... Fish early life stage toxicity test. (a) Purpose. This guideline is intended to be used for assessing...

40 CFR 797.1600 - Fish early life stage toxicity test.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the test solution concentrations. The test terminates following 60 days of post-hatch exposure (for an... 40 Protection of Environment 32 2011-07-01 2011-07-01 false Fish early life stage toxicity test... Fish early life stage toxicity test. (a) Purpose. This guideline is intended to be used for assessing...

Early life influences on cognitive impairment among oldest old Chinese.

PubMed

Zhang, Zhenmei; Gu, Danan; Hayward, Mark D

2008-01-01

This article examines the effects of early life socioeconomic conditions on the risk of cognitive impairment among oldest old persons in China. We also examine whether adult socioeconomic status mediates the association between early life socioeconomic status and cognitive impairment in old age. Data derived from two waves (1998-2000) of the Chinese Longitudinal Healthy Longevity Survey. We estimated logistic and multinomial regression models of cognitive impairment for a nationwide sample of people aged 80 to 105 (N = 8,444). Among both men and women, urban residence in early life as well as education was associated with lower odds of cognitive impairment at baseline. We found modest support for a protective effect of advantaged childhood background on the odds of cognitive impairment onset during the 2-year follow-up, especially among women. Our findings suggest that socioeconomic environment throughout the life course, early life in particular, can influence the risk of cognitive impairment in old age. Not only can public policy that targets illiteracy, hunger, and poverty improve the lives of tens of thousands of children, but ultimately such investments will pay significant dividends many decades later in enhancing the cognitive well-being of older persons.

The OBELIX project: early life exposure to endocrine disruptors and obesity.

PubMed

Legler, Juliette; Hamers, Timo; van Eck van der Sluijs-van de Bor, Margot; Schoeters, Greet; van der Ven, Leo; Eggesbo, Merete; Koppe, Janna; Feinberg, Max; Trnovec, Tomas

2011-12-01

The hypothesis of whether early life exposure (both pre- and early postnatal) to endocrine-disrupting chemicals (EDCs) may be a risk factor for obesity and related metabolic diseases later in life will be tested in the European research project OBELIX (OBesogenic Endocrine disrupting chemicals: LInking prenatal eXposure to the development of obesity later in life). OBELIX is a 4-y project that started in May 2009 and which has the following 5 main objectives: 1) to assess early life exposure in humans to major classes of EDCs identified as potential inducers of obesity (ie, dioxin-like compounds, non-dioxin-like polychlorinated biphenyls, organochlorine pesticides, brominated flame retardants, phthalates, and perfluorinated compounds) by using mother-child cohorts from 4 European regions with different food-contaminant exposure patterns; 2) to relate early life exposure to EDCs with clinical markers, novel biomarkers, and health-effect data related to obesity; 3) to perform hazard characterization of early life exposure to EDCs for the development of obesity later in life by using a mouse model; 4) to determine mechanisms of action of obesogenic EDCs on developmental programming with in vivo and in vitro genomics and epigenetic analyses; and 5) to perform risk assessments of prenatal exposure to obesogenic EDCs in food by integrating maternal exposure through food-contaminant exposure and health-effect data in children and hazard data in animal studies.

Early Life on Earth: the Ancient Fossil Record

NASA Astrophysics Data System (ADS)

Westall, F.

2004-07-01

The evidence for early life and its initial evolution on Earth is lin= ked intimately with the geological evolution of the early Earth. The environment of the early Earth would be considered extreme by modern standards: hot (50-80=B0C), volcanically and hydrothermally active, a= noxic, high UV flux, and a high flux of extraterrestrial impacts. Habitats = for life were more limited until continent-building processes resulted in= the formation of stable cratons with wide, shallow, continental platforms= in the Mid-Late Archaean. Unfortunately there are no records of the first appearance of life and the earliest isotopic indications of the exist= ence of organisms fractionating carbon in ~3.8 Ga rocks from the Isua greenst= one belt in Greenland are tenuous. Well-preserved microfossils and micro= bial mats (in the form of tabular and domical stromatolites) occur in 3.5-= 3.3 Ga, Early Archaean, sedimentary formations from the Barberton (South Afri= ca) and Pilbara (Australia) greenstone belts. They document life forms that = show a relatively advanced level of evolution. Microfossil morphology inclu= des filamentous, coccoid, rod and vibroid shapes. Colonial microorganism= s formed biofilms and microbial mats at the surfaces of volcaniclastic = and chemical sediments, some of which created (small) macroscopic microbi= alites such as stromatolites. Anoxygenic photosynthesis may already have developed. Carbon, nitrogen and sulphur isotopes ratios are in the r= ange of those for organisms with anaerobic metabolisms, such as methanogenesi= s, sulphate reduction and photosynthesis. Life was apparently distribute= d widely in shallow-water to littoral environments, including exposed, evaporitic basins and regions of hydrothermal activity. Biomass in t= he early Archaean was restricted owing to the limited amount of energy t= hat could be produced by anaerobic metabolisms. Microfossils resembling o= xygenic photosynthesisers, such as cyanobacteria, probably first occurred in

Early life linguistic ability, late life cognitive function, and neuropathology: findings from the Nun Study.

PubMed

Riley, Kathryn P; Snowdon, David A; Desrosiers, Mark F; Markesbery, William R

2005-03-01

The relationships between early life variables, cognitive function, and neuropathology were examined in participants in the Nun Study who were between the ages of 75 and 95. Our early life variable was idea density, which is a measure of linguistic ability, derived from autobiographies written at a mean age of 22 years. Six discrete categories of cognitive function, including mild cognitive impairments, were evaluated, using the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) battery of cognitive tests. Neuropathologic data included Braak staging, neurofibrillary tangle and senile plaque counts, brain weight, degree of cerebral atrophy, severity of atherosclerosis, and the presence of brain infarcts. Early-life idea density was significantly related to the categories of late-life cognitive function, including mild cognitive impairments: low idea density was associated with greater impairment. Low idea density also was significantly associated with lower brain weight, higher degree of cerebral atrophy, more severe neurofibrillary pathology, and the likelihood of meeting neuropathologic criteria for Alzheimer's disease.

Early life stress paradigms in rodents: potential animal models of depression?

PubMed

Schmidt, Mathias V; Wang, Xiao-Dong; Meijer, Onno C

2011-03-01

While human depressive illness is indeed uniquely human, many of its symptoms may be modeled in rodents. Based on human etiology, the assumption has been made that depression-like behavior in rats and mice can be modulated by some of the powerful early life programming effects that are known to occur after manipulations in the first weeks of life. Here we review the evidence that is available in literature for early life manipulation as risk factors for the development of depression-like symptoms such as anhedonia, passive coping strategies, and neuroendocrine changes. Early life paradigms that were evaluated include early handling, separation, and deprivation protocols, as well as enriched and impoverished environments. We have also included a small number of stress-related pharmacological models. We find that for most early life paradigms per se, the actual validity for depression is limited. A number of models have not been tested with respect to classical depression-like behaviors, while in many cases, the outcome of such experiments is variable and depends on strain and additional factors. Because programming effects confer vulnerability rather than disease, a number of paradigms hold promise for usefulness in depression research, in combination with the proper genetic background and adult life challenges.

The Origin of Life--Out of the Blue.

PubMed

Sutherland, John D

2016-01-04

Either to sustain autotrophy, or as a prelude to heterotrophy, organic synthesis from an environmentally available C1 feedstock molecule is crucial to the origin of life. Recent findings augment key literature results and suggest that hydrogen cyanide--"Blausäure"--was that feedstock. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

New insights into a hot environment for early life.

PubMed

Dai, Jianghong

2017-06-01

Investigating the physical-chemical setting of early life is a challenging task. In this contribution, the author attempted to introduce a provocative concept from cosmology - cosmic microwave background (CMB), which is the residual thermal radiation from a hot early Universe - to the field. For this purpose, the author revisited a recently deduced biomarker, the 1,6-anhydro bond of sugars in bacteria. In vitro, the 1,6-anhydro bond of sugars reflects and captures residual thermal radiation in thermochemical processes and therefore is somewhat analogous to CMB. In vivo, the formation process of the 1,6-anhydro bond of sugars on the peptidoglycan of prokaryotic cell wall is parallel to in vitro processes, suggesting that the 1,6-anhydro bond is an ideal CMB-like analogue that suggests a hot setting for early life. The CMB-like 1,6-anhydro bond is involved in the life cycle of viruses and the metabolism of eukaryotes, underlying this notion. From a novel perspective, the application of the concept of the CMB to microbial ecology may give new insights into a hot environment, such as hydrothermal vents, supporting early life and providing hypotheses to test in molecular palaeontology. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Beating the acetyl coenzyme A-pathway to the origin of life

PubMed Central

Nitschke, Wolfgang; Russell, Michael J.

2013-01-01

Attempts to draft plausible scenarios for the origin of life have in the past mainly built upon palaeogeochemical boundary conditions while, as detailed in a companion article in this issue, frequently neglecting to comply with fundamental thermodynamic laws. Even if demands from both palaeogeochemistry and thermodynamics are respected, then a plethora of strongly differing models are still conceivable. Although we have no guarantee that life at its origin necessarily resembled biology in extant organisms, we consider that the only empirical way to deduce how life may have emerged is by taking the stance of assuming continuity of biology from its inception to the present day. Building upon this conviction, we have assessed extant types of energy and carbon metabolism for their appropriateness to conditions probably pertaining in those settings of the Hadean planet that fulfil the thermodynamic requirements for life to come into being. Wood–Ljungdahl (WL) pathways leading to acetyl CoA formation are excellent candidates for such primordial metabolism. Based on a review of our present understanding of the biochemistry and biophysics of acetogenic, methanogenic and methanotrophic pathways and on a phylogenetic analysis of involved enzymes, we propose that a variant of modern methanotrophy is more likely than traditional WL systems to date back to the origin of life. The proposed model furthermore better fits basic thermodynamic demands and palaeogeochemical conditions suggested by recent results from extant alkaline hydrothermal seeps. PMID:23754811

Life satisfaction in early adolescence: personal, neighborhood, school, family, and peer influences.

PubMed

Oberle, Eva; Schonert-Reichl, Kimberly A; Zumbo, Bruno D

2011-07-01

Drawing from an ecological assets framework as well as research and theory on positive youth development, this study examined the relationship of early adolescents' satisfaction with life to trait optimism and assets representing the social contexts in which early adolescents spend most of their time. Self-reports of satisfaction with life, optimism, and ecological assets in the school (school connectedness), neighborhood (perceived neighborhood support), family (perceived parental support), and peer group (positive peer relationships) were assessed in a sample of 1,402 4th to 7th graders (47% female) from 25 public elementary schools. Multilevel modeling (MLM) was conducted to analyze the variability in life satisfaction both at the individual and the school level. As hypothesized, adding optimism and the dimensions representing the ecology of early adolescence to the model significantly reduced the variability in life satisfaction at both levels of analysis. Both personal (optimism) and all of the ecological assets significantly and positively predicted early adolescents' life satisfaction. The results suggest the theoretical and practical utility of an assets approach for understanding life satisfaction in early adolescence.

Information-Theoretic Considerations Concerning the Origin of Life

NASA Astrophysics Data System (ADS)

Adami, Christoph

2015-09-01

Research investigating the origins of life usually either focuses on exploring possible life-bearing chemistries in the pre-biotic Earth, or else on synthetic approaches. Comparatively little work has explored fundamental issues concerning the spontaneous emergence of life using only concepts (such as information and evolution) that are divorced from any particular chemistry. Here, I advocate studying the probability of spontaneous molecular self-replication as a function of the information contained in the replicator, and the environmental conditions that might enable this emergence. I show (under certain simplifying assumptions) that the probability to discover a self-replicator by chance depends exponentially on the relative rate of formation of the monomers. If the rate at which monomers are formed is somewhat similar to the rate at which they would occur in a self-replicating polymer, the likelihood to discover such a replicator by chance is increased by many orders of magnitude. I document such an increase in searches for a self-replicator within the digital life system avida.

Formal and Informal Early Education of Turkish-Origin Children in Germany

ERIC Educational Resources Information Center

Becker, Birgit; Boldin, Elena; Klein, Oliver

2016-01-01

A lack of adequate German language skills is often discussed as a major reason for the disadvantage of children of immigrants in the German educational system. This article analyses the access to formal and informal early education of Turkish-origin children in Germany and the influence of these early education contexts on the children's German…

The origin of introns and their role in eukaryogenesis: a compromise solution to the introns-early versus introns-late debate?

PubMed Central

Koonin, Eugene V

2006-01-01

Background Ever since the discovery of 'genes in pieces' and mRNA splicing in eukaryotes, origin and evolution of spliceosomal introns have been considered within the conceptual framework of the 'introns early' versus 'introns late' debate. The 'introns early' hypothesis, which is closely linked to the so-called exon theory of gene evolution, posits that protein-coding genes were interrupted by numerous introns even at the earliest stages of life's evolution and that introns played a major role in the origin of proteins by facilitating recombination of sequences coding for small protein/peptide modules. Under this scenario, the absence of spliceosomal introns in prokaryotes is considered to be a result of "genome streamlining". The 'introns late' hypothesis counters that spliceosomal introns emerged only in eukaryotes, and moreover, have been inserted into protein-coding genes continuously throughout the evolution of eukaryotes. Beyond the formal dilemma, the more substantial side of this debate has to do with possible roles of introns in the evolution of eukaryotes. Results I argue that several lines of evidence now suggest a coherent solution to the introns-early versus introns-late debate, and the emerging picture of intron evolution integrates aspects of both views although, formally, there seems to be no support for the original version of introns-early. Firstly, there is growing evidence that spliceosomal introns evolved from group II self-splicing introns which are present, usually, in small numbers, in many bacteria, and probably, moved into the evolving eukaryotic genome from the α-proteobacterial progenitor of the mitochondria. Secondly, the concept of a primordial pool of 'virus-like' genetic elements implies that self-splicing introns are among the most ancient genetic entities. Thirdly, reconstructions of the ancestral state of eukaryotic genes suggest that the last common ancestor of extant eukaryotes had an intron-rich genome. Thus, it appears that

Extremophiles may be irrelevant to the origin of life.

PubMed

Cleaves, H James; Chalmers, John H

2004-01-01

In recent years, Bacteria and Archaea have been discovered living in practically every conceivable terrestrial environment, including some previously thought to be too extreme for survival. Exploration of our solar system has revealed a number of extraterrestrial bodies that harbor environments analogous to many of the terrestrial environments in which extremophiles flourish. The recent discovery of more than 105 extrasolar planets suggests that planetary systems are quite common. These three findings have led some to speculate that life is therefore common in the universe, as life as we know it can seemingly survive almost anywhere there is liquid water. It is suggested here that while environments capable of supporting life may be common, this does not in itself support the notion that life is common in the universe. Given that interplanetary transfer of life may be unlikely, the actual origin of life may require specific environmental and geological conditions that may be much less common than the mere existence of liquid water.

Maternal Smoking and the Risk of Cancer in Early Life - A Meta-Analysis.

PubMed

Rumrich, Isabell Katharina; Viluksela, Matti; Vähäkangas, Kirsi; Gissler, Mika; Surcel, Heljä-Marja; Hänninen, Otto

2016-01-01

In spite of the well-known harmful effects on the fetus, many women continue smoking during pregnancy. Smoking as an important source of toxic chemicals may contribute to the developmental origin of diseases. The aim of this work was to pursue the possible association between maternal smoking and cancer in early life. Specifically, we wanted to identify the associated early life cancer types, and to quantify the associations. In a systematic literature search 825 articles were identified in PubMed and Web of Science, and 55 more through the reference lists. Of these 62 fulfilled the criteria for inclusion in meta-analyses. Using Mantel-Haenszel or DerSimonian and Laird method, depending on heterogeneity of the studies, pooled estimates and 95% confidence intervals for eight cancer types were calculated. Smoking during pregnancy was associated with an increased risk for for brain and central nervous system tumors (OR = 1.09; 95% CI = 1.02-1.17). Although the risk for lymphoma was also associated (OR = 1.21; 95% CI = 1.05-1.34), it did not hold up in subgroup analyses. Leukemia was not found to be associated with maternal smoking. Five other cancer types (bone, soft tissue, renal, hepatic, and germ cell cancer) were also examined, but the number of studies was too limited to exclude the possibility of maternal smoking as a risk factor for cancer in offspring. According to our meta-analyses, maternal smoking is associated with nervous system cancers, but not with leukemia in early life. Confirming or rejecting associations of maternal smoking with lymphoma and the five other cancer types requires further studies.

Early life socioeconomic position and immune response to persistent infections among elderly Latinos.

PubMed

Meier, Helen C S; Haan, Mary N; Mendes de Leon, Carlos F; Simanek, Amanda M; Dowd, Jennifer B; Aiello, Allison E

2016-10-01

Persistent infections, such as cytomegalovirus (CMV), herpes simplex virus-1 (HSV-1), Helicobacter pylori (H. pylori), and Toxoplasma gondii (T. gondii), are common in the U.S. but their prevalence varies by socioeconomic status. It is unclear if early or later life socioeconomic position (SEP) is a more salient driver of disparities in immune control of these infections. Using data from the Sacramento Area Latino Study on Aging, we examined whether early or later life SEP was the strongest predictor of immune control later in life by contrasting two life course models, the critical period model and the chain of risk model. Early life SEP was measured as a latent variable, derived from parental education and occupation, and food availability. Indicators for SEP in later life included education level and occupation. Individuals were categorized by immune response to each pathogen (seronegative, low, medium and high) with increasing immune response representing poorer immune control. Cumulative immune response was estimated using a latent profile analysis with higher total immune response representing poorer immune control. Structural equation models were used to examine direct, indirect and total effects of early life SEP on each infection and cumulative immune response, controlling for age and gender. The direct effect of early life SEP on immune response was not statistically significant for the infections or cumulative immune response. Higher early life SEP was associated with lower immune response for T. gondii, H. pylori and cumulative immune response through pathways mediated by later life SEP. For CMV, higher early life SEP was both directly associated and partially mediated by later life SEP. No association was found between SEP and HSV-1. Findings from this study support a chain of risk model, whereby early life SEP acts through later life SEP to affect immune response to persistent infections in older age. Copyright © 2016 Elsevier Ltd. All rights

The composition of the gut microbiota throughout life, with an emphasis on early life

PubMed Central

Rodríguez, Juan Miguel; Murphy, Kiera; Stanton, Catherine; Ross, R. Paul; Kober, Olivia I.; Juge, Nathalie; Avershina, Ekaterina; Rudi, Knut; Narbad, Arjan; Jenmalm, Maria C.; Marchesi, Julian R.; Collado, Maria Carmen

2015-01-01

The intestinal microbiota has become a relevant aspect of human health. Microbial colonization runs in parallel with immune system maturation and plays a role in intestinal physiology and regulation. Increasing evidence on early microbial contact suggest that human intestinal microbiota is seeded before birth. Maternal microbiota forms the first microbial inoculum, and from birth, the microbial diversity increases and converges toward an adult-like microbiota by the end of the first 3–5 years of life. Perinatal factors such as mode of delivery, diet, genetics, and intestinal mucin glycosylation all contribute to influence microbial colonization. Once established, the composition of the gut microbiota is relatively stable throughout adult life, but can be altered as a result of bacterial infections, antibiotic treatment, lifestyle, surgical, and a long-term change in diet. Shifts in this complex microbial system have been reported to increase the risk of disease. Therefore, an adequate establishment of microbiota and its maintenance throughout life would reduce the risk of disease in early and late life. This review discusses recent studies on the early colonization and factors influencing this process which impact on health. PMID:25651996

Life Origination Hydrate Hypothesis (LOH-Hypothesis)

PubMed Central

Ostrovskii, Victor; Kadyshevich, Elena

2012-01-01

The paper develops the Life Origination Hydrate Hypothesis (LOH-hypothesis), according to which living-matter simplest elements (LMSEs, which are N-bases, riboses, nucleosides, nucleotides), DNA- and RNA-like molecules, amino-acids, and proto-cells repeatedly originated on the basis of thermodynamically controlled, natural, and inevitable processes governed by universal physical and chemical laws from CH4, niters, and phosphates under the Earth's surface or seabed within the crystal cavities of the honeycomb methane-hydrate structure at low temperatures; the chemical processes passed slowly through all successive chemical steps in the direction that is determined by a gradual decrease in the Gibbs free energy of reacting systems. The hypothesis formulation method is based on the thermodynamic directedness of natural movement and consists ofan attempt to mentally backtrack on the progression of nature and thus reveal principal milestones alongits route. The changes in Gibbs free energy are estimated for different steps of the living-matter origination process; special attention is paid to the processes of proto-cell formation. Just the occurrence of the gas-hydrate periodic honeycomb matrix filled with LMSEs almost completely in its final state accounts for size limitation in the DNA functional groups and the nonrandom location of N-bases in the DNA chains. The slowness of the low-temperature chemical transformations and their “thermodynamic front” guide the gross process of living matter origination and its successive steps. It is shown that the hypothesis is thermodynamically justified and testable and that many observed natural phenomena count in its favor. PMID:25382120

The origin and evolution of model organisms

NASA Technical Reports Server (NTRS)

Hedges, S. Blair

2002-01-01

The phylogeny and timescale of life are becoming better understood as the analysis of genomic data from model organisms continues to grow. As a result, discoveries are being made about the early history of life and the origin and development of complex multicellular life. This emerging comparative framework and the emphasis on historical patterns is helping to bridge barriers among organism-based research communities.

How life began.

PubMed

Cloud, P

1986-11-01

Study of the origin of life has become a legitimate scientific inquiry, with an international, multidisciplinary membership and a cogent body of data. Experiments involving plausible early Earth conditions and biogeochemical analyses of carbonaceous meteorites imply a variety of available starting molecules. Biogeological evidence indicates microbial beginnings about 3800 million years (3.8 aeons) ago. By then the known universe had been in existence for perhaps 15 aeons and galaxies abundant for ten. Conditions suitable for the origin of life may require a long prior cosmic evolution. The natural origin of life on the early Earth is now widely agreed upon but not the pathways. The beginnings of catalysis, replication and a functional cell remain moot. Much discussion has centered on the templating role that crystals such as clays and zeolites might have played in prebiotic evolution. Recent discovery of the catalytic and replicative functions of RNA recommend it as the key molecule in the transition from chemical to biological evolution. Copyright © 1986. Published by Elsevier Ltd.

The die is cast - Arsenic exposure in early life and disease susceptibility

EPA Science Inventory

Abstract Early life exposure to arsenic in humans and mice produces similar patterns of disease in later life. Given the long interval between exposure and effect, epigenetic effects of early life exposure to arsenic may account for development and progression of disease in bo...

Association of early- and adult-life socioeconomic circumstances with muscle strength in older age.

PubMed

Cheval, Boris; Boisgontier, Matthieu P; Orsholits, Dan; Sieber, Stefan; Guessous, Idris; Gabriel, Rainer; Stringhini, Silvia; Blane, David; van der Linden, Bernadette W A; Kliegel, Matthias; Burton-Jeangros, Claudine; Courvoisier, Delphine S; Cullati, Stéphane

2018-05-01

socioeconomic circumstances (SEC) during a person's lifespan influence a wide range of health outcomes. However, solid evidence of the association of early- and adult-life SEC with health trajectories in ageing is still lacking. This study assessed whether early-life SEC are associated with muscle strength in later life-a biomarker of health-and whether this relationship is caused by adult-life SEC and health behaviours. we used data from the Survey of Health Ageing and Retirement in Europe, a 12-year population-based cohort study with repeated measurement in six waves (2004-15) and retrospective collection of life-course data. Participants' grip strength was assessed by using a handheld dynamometer. Confounder-adjusted logistic mixed-effect models were used to examine the associations of early- and adult-life SEC with the risk of low muscle strength (LMS) in older age. a total of 24,179 participants (96,375 observations) aged 50-96 living in 14 European countries were included in the analyses. Risk of LMS was increased with disadvantaged relative to advantaged early-life SEC. The association between risk of LMS and disadvantaged early-life SEC gradually decreased when adjusting for adult-life SEC for both sexes and with unhealthy behaviours for women. After adjusting for these factors, all associations between risk of LMS and early-life SEC remained significant for women. early-life SEC are associated with muscle strength after adjusting for adult-life SEC and behavioural lifestyle factors, especially in women, which suggests that early life may represent a sensitive period for future health.

The origin of life at the origin of ageing?

PubMed

Currais, Antonio

2017-05-01

At first glance, the ageing of unicellular organisms would appear to be different from the ageing of complex, multicellular organisms. In an attempt to describe the nature of ageing in diverse organisms, the intimate links between the origins of life and ageing are examined. Departing from Leslie Orgel's initial ideas on why organisms age, it is then discussed how the potentially detrimental events characteristic of ageing are continuous, cell-autonomous and universal to all organisms. The manifestation of these alterations relies on the balance between their production and cellular renewal. Renewal is achieved not only by repair and maintenance mechanisms but, importantly, by the process of cell division such that every time cells divide ageing-associated effects are diluted. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparison of early maladaptive schemas and parenting origins in patients with opioid abuse and non-abusers.

PubMed

Jalali, Mohammad Reza; Zargar, Mohammad; Salavati, Mojgan; Kakavand, Ali Reza

2011-01-01

The aim of this study was to examine the difference of early maladaptive schemas and parenting origins in opioid abusers and non-opioid abusers. The early maladaptive schemas and parenting origins were compared in 56 opioid abusers and 56 non-opioids abusers. Schemas were assessed by the Young Schema Questionnaire 3rd (short form); and parenting origins were assessed by the Young Parenting Inventory. Data were analyzed by multivariate analysis of variance (MANOVA). The analysis showed that the means for schemas between opioid abusers and non-opioid abusers were different. Chi square test showed that parenting origins were significantly associated with their related schemas. The early maladaptive schemas and parenting origins in opioid abusers were more than non-opioid abusers; and parenting origins were related to their Corresponding schemas.

Early-Life Effects on Adult Physical Activity: Concepts, Relevance, and Experimental Approaches.

PubMed

Garland, Theodore; Cadney, Marcell D; Waterland, Robert A

Locomotion is a defining characteristic of animal life and plays a crucial role in most behaviors. Locomotion involves physical activity, which can have far-reaching effects on physiology and neurobiology, both acutely and chronically. In human populations and in laboratory rodents, higher levels of physical activity are generally associated with positive health outcomes, although excessive exercise can have adverse consequences. Whether and how such relationships occur in wild animals is unknown. Behavioral variation among individuals arises from genetic and environmental factors and their interactions as well as from developmental programming (persistent effects of early-life environment). Although tremendous progress has been made in identifying genetic and environmental influences on individual differences in behavior, early-life effects are not well understood. Early-life effects can in some cases persist across multiple generations following a single exposure and, in principle, may constrain or facilitate the rate of evolution at multiple levels of biological organization. Understanding the mechanisms of such transgenerational effects (e.g., exposure to stress hormones in utero, inherited epigenetic alterations) may prove crucial to explaining unexpected and/or sex-specific responses to selection as well as limits to adaptation. One area receiving increased attention is early-life effects on adult physical activity. Correlational data from epidemiological studies suggest that early-life nutritional stress can (adversely) affect adult human activity levels and associated physiological traits (e.g., body composition, metabolic health). The few existing studies of laboratory rodents demonstrate that both maternal and early-life exercise can affect adult levels of physical activity and related phenotypes. Going forward, rodents offer many opportunities for experimental studies of (multigenerational) early-life effects, including studies that use maternal

The human early-life exposome (HELIX): project rationale and design.

PubMed

Vrijheid, Martine; Slama, Rémy; Robinson, Oliver; Chatzi, Leda; Coen, Muireann; van den Hazel, Peter; Thomsen, Cathrine; Wright, John; Athersuch, Toby J; Avellana, Narcis; Basagaña, Xavier; Brochot, Celine; Bucchini, Luca; Bustamante, Mariona; Carracedo, Angel; Casas, Maribel; Estivill, Xavier; Fairley, Lesley; van Gent, Diana; Gonzalez, Juan R; Granum, Berit; Gražulevičienė, Regina; Gutzkow, Kristine B; Julvez, Jordi; Keun, Hector C; Kogevinas, Manolis; McEachan, Rosemary R C; Meltzer, Helle Margrete; Sabidó, Eduard; Schwarze, Per E; Siroux, Valérie; Sunyer, Jordi; Want, Elizabeth J; Zeman, Florence; Nieuwenhuijsen, Mark J

2014-06-01

Developmental periods in early life may be particularly vulnerable to impacts of environmental exposures. Human research on this topic has generally focused on single exposure-health effect relationships. The "exposome" concept encompasses the totality of exposures from conception onward, complementing the genome. The Human Early-Life Exposome (HELIX) project is a new collaborative research project that aims to implement novel exposure assessment and biomarker methods to characterize early-life exposure to multiple environmental factors and associate these with omics biomarkers and child health outcomes, thus characterizing the "early-life exposome." Here we describe the general design of the project. In six existing birth cohort studies in Europe, HELIX will estimate prenatal and postnatal exposure to a broad range of chemical and physical exposures. Exposure models will be developed for the full cohorts totaling 32,000 mother-child pairs, and biomarkers will be measured in a subset of 1,200 mother-child pairs. Nested repeat-sampling panel studies (n = 150) will collect data on biomarker variability, use smartphones to assess mobility and physical activity, and perform personal exposure monitoring. Omics techniques will determine molecular profiles (metabolome, proteome, transcriptome, epigenome) associated with exposures. Statistical methods for multiple exposures will provide exposure-response estimates for fetal and child growth, obesity, neurodevelopment, and respiratory outcomes. A health impact assessment exercise will evaluate risks and benefits of combined exposures. HELIX is one of the first attempts to describe the early-life exposome of European populations and unravel its relation to omics markers and health in childhood. As proof of concept, it will form an important first step toward the life-course exposome.

Early-life income inequality and adolescent health and well-being.

PubMed

Elgar, Frank J; Gariépy, Geneviève; Torsheim, Torbjørn; Currie, Candace

2017-02-01

A prevailing hypothesis about the association between income inequality and poor health is that inequality intensifies social hierarchies, increases stress, erodes social and material resources that support health, and subsequently harms health. However, the evidence in support of this hypothesis is limited by cross-sectional, ecological studies and a scarcity of developmental studies. To address this limitation, we used pooled, multilevel data from the Health Behaviour in School-aged Children study to examine lagged, cumulative, and trajectory associations between early-life income inequality and adolescent health and well-being. Psychosomatic symptoms and life satisfaction were assessed in surveys of 11- to 15-year-olds in 40 countries between 1994 and 2014. We linked these data to national Gini indices of income inequality for every life year from 1979 to 2014. The results showed that exposure to income inequality from 0 to 4 years predicted psychosomatic symptoms and lower life satisfaction in females after controlling lifetime mean income inequality, national per capita income, family affluence, age, and cohort and period effects. The cumulative income inequality exposure in infancy and childhood (i.e., average Gini index from birth to age 10) related to lower life satisfaction in female adolescents but not to symptoms. Finally, individual trajectories in early-life inequality (i.e., linear slopes in Gini indices from birth to 10 years) related to fewer symptoms and higher life satisfaction in females, indicating that earlier exposures mattered more to predicting health and wellbeing. No such associations with early-life income inequality were found in males. These results help to establish the antecedent-consequence conditions in the association between income inequality and health and suggest that both the magnitude and timing of income inequality in early life have developmental consequences that manifest in reduced health and well-being in adolescent girls

Serpentinization and its implications for life on the early Earth and Mars.

PubMed

Schulte, Mitch; Blake, David; Hoehler, Tori; McCollom, Thomas

2006-04-01

Ophiolites, sections of ocean crust tectonically displaced onto land, offer significant potential to support chemolithoautotrophic life through the provision of energy and reducing power during aqueous alteration of their highly reduced mineralogies. There is substantial chemical disequilibrium between the primary olivine and pyroxene mineralogy of these ophiolites and the fluids circulating through them. This disequilibrium represents a potential source of chemical energy that could sustain life. Moreover, E (h)-pH conditions resulting from rock- water interactions in ultrabasic rocks are conducive to important abiotic processes antecedent to the origin of life. Serpentinization--the reaction of olivine- and pyroxene-rich rocks with water--produces magnetite, hydroxide, and serpentine minerals, and liberates molecular hydrogen, a source of energy and electrons that can be readily utilized by a broad array of chemosynthetic organisms. These systems are viewed as important analogs for potential early ecosystems on both Earth and Mars, where highly reducing mineralogy was likely widespread in an undifferentiated crust. Secondary phases precipitated during serpentinization have the capability to preserve organic or mineral biosignatures. We describe the petrology and mineral chemistry of an ophiolite-hosted cold spring in northern California and propose criteria to aid in the identification of serpentinizing terranes on Mars that have the potential to harbor chemosynthetic life.

Serpentinization and Its Implications for Life on the Early Earth and Mars

NASA Astrophysics Data System (ADS)

Schulte, Mitch; Blake, David; Hoehler, Tori; McCollom, Thomas

2006-04-01

Ophiolites, sections of ocean crust tectonically displaced onto land, offer significant potential to support chemolithoautotrophic life through the provision of energy and reducing power during aqueous alteration of their highly reduced mineralogies. There is substantial chemical disequilibrium between the primary olivine and pyroxene mineralogy of these ophiolites and the fluids circulating through them. This disequilibrium represents a potential source of chemical energy that could sustain life. Moreover, E h-pH conditions resulting from rock- water interactions in ultrabasic rocks are conducive to important abiotic processes antecedent to the origin of life. Serpentinization-the reaction of olivine- and pyroxene-rich rocks with water-produces magnetite, hydroxide, and serpentine minerals, and liberates molecular hydrogen, a source of energy and electrons that can be readily utilized by a broad array of chemosynthetic organisms. These systems are viewed as important analogs for potential early ecosystems on both Earth and Mars, where highly reducing mineralogy was likely widespread in an undifferentiated crust. Secondary phases precipitated during serpentinization have the capability to preserve organic or mineral biosignatures. We describe the petrology and mineral chemistry of an ophiolite-hosted cold spring in northern California and propose criteria to aid in the identification of serpentinizing terranes on Mars that have the potential to harbor chemosynthetic life.

Children of Misfortune: Early Adversity and Cumulative Inequality in Perceived Life Trajectories1

PubMed Central

Schafer, Markus H.; Ferraro, Kenneth F.; Mustillo, Sarah A.

2011-01-01

Adversity early in life may alter pathways of aging, but what interpretive processes can soften the blow of early insults? Drawing from cumulative inequality theory, the authors analyze trajectories of life evaluations and then consider whether early adversity offsets favorable expectations for the future. Results reveal that early adversity contributes to more negative views of the past but rising expectations for the future. Early adversity also has enduring effects on life evaluations, offsetting the influence of buoyant expectations. The findings draw attention to the limits of human agency under the constraints of early adversity—a process described as biographical structuration. PMID:21648247

Xenohormesis in early life: New avenues of research to explore anti-aging strategies through the maternal diet.

PubMed

de Medina, Philippe

2017-11-01

Aging is a progressive internal physiological deterioration of the organism, leading to the occurrence of age-related lethal diseases. It has become a major societal challenge to understand the processes that drive aging and to develop rational pharmacological agents and dietary approaches to fight against age-related deterioration and diseases. Interestingly, several lines of evidence highlight an influence of the developmental period on the risk of age-related diseases later in life. This field is known as the developmental origins of health and disease. Following this logic, studying the modification of maternal diet during early life may provide innovative new anti-aging approaches. Nutritional and psychological stresses during gestation are associated with poorer offspring health conditions in late life, and must be avoided during pregnancy. Besides these recommendations, very little has been published about the possible use of maternal diet to program offspring for healthy aging and an extended lifespan. Such health benefits may be provided by different foreign molecules, and particularly the phytochemicals produced by stressed plants, or xenohormetins. The xenohormesis hypothesis proposes that xenohormetins are signals of environmental change and trigger a beneficial adaptive response in individuals who consume them. No studies to date have investigated whether the consumption of stressed plants during pregnancy and lactation could provide chemical cues that impact early life programming and thus influence the future health and lifespan of offspring. Investigating the effect of xenohormesis in early life will involve adding edible plants exposed to different stressors (i.e. UV light, heat, ozone, etc.) to maternal diet and the exposure of offspring to this xenohormetin-enriched maternal diet at different periods of their prenatal life. The hypothesis proposed in this article is a potential tool to decipher the possible impact of xenohormesis during early

Global Research Trends on Early-Life Feeding Practices and Early Childhood Caries: a Systematic Review

PubMed Central

Cheng, Ashley

2014-01-01

Objective Describe the epidemiologic literature related to early-life feeding practices and early childhood caries (ECC) with regard to publication attributes and trends in these attributes over time. Methods Systematic literature review including electronic and manual searches (in BIOSIS, CINAHL, Cochrane Library, LILACS, MEDLINE, Web of Science, and WHOLIS), covering the years 1990–2013. Attributes of publications meeting a priori inclusion criteria were abstracted and organized by global region and trends over time. Attributes included country of origin and study design of included publications and age and caries prevalence of the populations studied. Results 244 publications drawn from 196 independent study populations were included. The number of publications and the countries represented increased over time, although some world regions remained underrepresented. Most publications were cross sectional (75%); while this percentage remained fairly constant over time, the percentage of studies to account for confounding factors increased. Publications varied with respect to the caries experience and age range of children included in each study. Conclusions Publication productivity regarding feeding practices and ECC research has grown, but this growth has not been evenly distributed globally. Individual publication attributes (i.e. methods and context) can differ significantly and should be considered when interpreting and synthesizing the literature. PMID:25328911

Modeling old-age wealth with endogenous early-life outcomes: The case of Mexico

PubMed Central

DeGraff, Deborah S.; Wong, Rebeca

2014-01-01

This paper contributes to the literature on the life course and aging by examining the association between early-life outcomes and late-life well being, using data from the Mexican Health and Aging Study. Empirical research in this area has been challenged by the potential endogeneity of the early-life outcomes of interest, an issue which most studies ignore or downplay. Our contribution takes two forms: (1) we examine in detail the potential importance of two key life-cycle outcomes, age at marriage (a measure of family formation) and years of educational attainment (a measure of human capital investment) for old-age wealth, and (2) we illustrate the empirical value of past context variables that could help model the association between early-life outcomes and late-life well being. Our illustrative approach, matching macro-level historical policy and census variables to individual records to use as instruments in modeling the endogeneity of early-life behaviors, yields a statistically identified two-stage model of old-age wealth with minimum bias. We use simulations to show that the results for the model of wealth in old age are meaningfully different when comparing the approach that accounts for endogeneity with an approach that assumes exogeneity of early-life outcomes. Furthermore, our results suggest that in the Mexican case, models which ignore the potential endogeneity of early-life outcomes are likely to under-estimate the effects of such variables on old-age wealth. PMID:25170434

Impact of solar system exploration on theories of chemical evolution and the origin of life

NASA Technical Reports Server (NTRS)

Devincenzi, D. L.

1983-01-01

The impact of solar system exploration on theories regarding chemical evolution and the origin of life is examined in detail. Major findings from missions to Mercury, Venus, the moon, Mars, Jupiter, Saturn, and Titan are reviewed and implications for prebiotic chemistry are discussed. Among the major conclusions are: prebiotic chemistry is widespread throughout the solar system and universe; chemical evolution and the origin of life are intimately associated with the origin and evolution of the solar system; the rate, direction, and extent of prebiotic chemistry is highly dependent upon planetary characteristics; and continued exploration will increase understanding of how life originated on earth and allow better estimates of the likelihood of similar processes occurring elsewhere.

Dietary factors during early life program bone formation in female rats

USDA-ARS?s Scientific Manuscript database

Nutritional status during intrauterine and early postnatal life impacts the risk of chronic diseases; however, evidence for an association between early life dietary factors and bone health in adults is limited. Soy protein isolate (SPI) may be one such dietary factor that promotes bone accretion du...

Meteoritic Input of Amino Acids and Nucleobases: Methodology and Implications for the Origins of Life

NASA Technical Reports Server (NTRS)

Burton, Aaron S.; Stern, Jennifer C.; Elsila, Jamie E.; Glavin, Daniel P.; Dworkin, Jason P.

2012-01-01

The discoveries of amino acids of extraterrestrial origin in many meteorites over the last 40 years have revolutionized the Astrobiology field. A variety of non-terrestrial amino acids similar to those found in life on Earth have been detected in meteorites. A few amino acids have even been found with chiral excesses, suggesting that meteorites could have contributed to the origin of homochirality in life on Earth. In addition to amino acids, which have been productively studied for years, sugar-like molecules, activated phosphates, and nucleobases have also been determined to be indigenous to numerous meteorites. Because these molecules are essential for life as we know it, and meteorites have been delivering them to the Earth since accretion, it is plausible that the origin(s) of life on Earth were aided by extraterrestrially-synthesized molecules. Understanding the origins of life on Earth guides our search for life elsewhere, helping to answer the question of whether biology is unique to Earth. This tutorial review focuses on meteoritic amino acids and nucleobases, exploring modern analytical methods and possible formation mechanisms. We will also discuss the unique window that meteorites provide into the chemistry that preceded life on Earth, a chemical record we do not have access to on Earth due to geologic recycling of rocks and the pervasiveness of biology across the planet. Finally, we will address the future of meteorite research, including asteroid sample return mIssIons.

Earliest evidence of modern human life history in North African early Homo sapiens.

PubMed

Smith, Tanya M; Tafforeau, Paul; Reid, Donald J; Grün, Rainer; Eggins, Stephen; Boutakiout, Mohamed; Hublin, Jean-Jacques

2007-04-10

Recent developmental studies demonstrate that early fossil hominins possessed shorter growth periods than living humans, implying disparate life histories. Analyses of incremental features in teeth provide an accurate means of assessing the age at death of developing dentitions, facilitating direct comparisons with fossil and modern humans. It is currently unknown when and where the prolonged modern human developmental condition originated. Here, an application of x-ray synchrotron microtomography reveals that an early Homo sapiens juvenile from Morocco dated at 160,000 years before present displays an equivalent degree of tooth development to modern European children at the same age. Crown formation times in the juvenile's macrodont dentition are higher than modern human mean values, whereas root development is accelerated relative to modern humans but is less than living apes and some fossil hominins. The juvenile from Jebel Irhoud is currently the oldest-known member of Homo with a developmental pattern (degree of eruption, developmental stage, and crown formation time) that is more similar to modern H. sapiens than to earlier members of Homo. This study also underscores the continuing importance of North Africa for understanding the origins of human anatomical and behavioral modernity. Corresponding biological and cultural changes may have appeared relatively late in the course of human evolution.

Community living long before man: fossil and living microbial mats and early life

NASA Technical Reports Server (NTRS)

Margulis, L.; Lopez Baluja, L.; Awramik, S. M.; Sagan, D.

1986-01-01

Microbial mats are layered communities of bacteria that form cohesive structures, some of which are preserved in sedimentary rocks as stromatolites. Certain rocks, approximately three and a half thousand million years old and representing the oldest known fossils, are interpreted to derive from microbial mats and to contain fossils of microorganisms. Modern microbial mats (such as the one described here from Matanzas, Cuba) and their fossil counterparts are of great interest in the interpretation of early life on Earth. Since examination of microbial mats and stromatolites increases our understanding of long-term stability and change, within the global environment, such structures should be protected wherever possible as natural science preserves. Furthermore, since they have existed virtually from the time of life's origin, microbial mats have developed exemplary mechanisms of local community persistence and may even play roles in the larger global environment that we do not understand.

The Relationship Between Early Life Events, Parental Attachment, and Psychopathic Tendencies in Adolescent Detainees.

PubMed

Christian, Erica J; Meltzer, Christine L; Thede, Linda L; Kosson, David S

2017-04-01

Despite increasing interest in understanding psychopathic traits in youth, the role of early environmental factors in the development of psychopathic traits is not well understood. No prior studies have directly examined the relationship between early life events and psychopathic traits. We examined links between life events in the first 4 years of life and indices of the core affective and interpersonal components of psychopathy. Additionally, we examined relationships between early life events, psychopathic traits, and attachment to parents among 206 adjudicated adolescents. Results indicated that the total number of early life events was positively correlated with indices of the affective component of psychopathy. Moreover, psychopathic traits moderated the relationship between the number of early life events and later reports of attachment to parents. Findings suggest that early environmental factors could have important implications for the development of psychopathic traits and may impact attachment to parents for youth with psychopathic traits.

The importance of early life in childhood obesity and related diseases: a report from the 2014 Gravida Strategic Summit.

PubMed

Macaulay, E C; Donovan, E L; Leask, M P; Bloomfield, F H; Vickers, M H; Dearden, P K; Baker, P N

2014-12-01

Obesity and its related non-communicable diseases (NCDs), such as type 2 diabetes, heart disease and cancer, impose huge burdens on society, particularly the healthcare system. Until recently, public health and policy were primarily focused on secondary prevention and treatment of NCDs. However, epidemiological and experimental evidence indicates that early-life exposures influence the risk of childhood obesity and related diseases later in life, and has now focused attention on the health of both mother and child. During pregnancy and the early neonatal period, individuals respond to their environment by establishing anatomical, physiological and biochemical trajectories that shape their future health. This period of developmental plasticity provides an early window of opportunity to mitigate the environmental insults that may increase an individual's sensitivity to, or risk of, developing obesity or related diseases later in life. Although much investigation has already occurred in the area of Developmental Origins of Health and Disease research, the science itself is still in its infancy. It remains for researchers to tackle the important outstanding questions and translate their knowledge into workable solutions for the public good. The challenge, however, is to decide which areas to focus on. With these opportunities and challenges in mind, the 2014 Gravida Summit convened to examine how its early-life research program can determine which areas of research into mechanisms, biomarkers and interventions could contribute to the international research strategy to fight childhood obesity and its related diseases.

The RNA World as a Model System to Study the Origin of Life.

PubMed

Pressman, Abe; Blanco, Celia; Chen, Irene A

2015-10-05

Understanding how life arose is a fundamental problem of biology. Much progress has been made by adopting a synthetic and mechanistic perspective on originating life. We present a current view of the biochemistry of the origin of life, focusing on issues surrounding the emergence of an RNA World in which RNA dominated informational and functional roles. There is cause for optimism on this difficult problem: the prebiotic chemical inventory may not have been as nightmarishly complex as previously thought; the catalytic repertoire of ribozymes continues to expand, approaching the goal of self-replicating RNA; encapsulation in protocells provides evolutionary and biophysical advantages. Nevertheless, major issues remain unsolved, such as the origin of a genetic code. Attention to this field is particularly timely given the accelerating discovery and characterization of exoplanets. Copyright © 2015 Elsevier Ltd. All rights reserved.

Life's origin: the cosmic, planetary and biological processes

NASA Technical Reports Server (NTRS)

Scattergood, T.; Des Marais, D.; Jahnke, L.

1987-01-01

From elements formed in interstellar furnaces to humans peering back at the stars, the evolution of life has been a long, intricate and perhaps inevitable process. Life as we know it requires a planet orbiting a star at just the right distance so that water can exist in liquid form. It needs a rich supply of chemicals and energy sources. On Earth, the combination of chemistry and energy generated molecules that evolved ways of replicating themselves and of passing information from one generation to the next. Thus, the thread of life began. This chart traces the thread, maintained by DNA molecules for much of its history, as it weaves its way through the primitive oceans, gaining strength and diversity along the way. Organisms eventually moved onto the land, where advanced forms, including humans, ultimately arose. Finally, assisted by a technology of its own making, life has reached back out into space to understand its own origins, to expand into new realms, and to seek other living threads in the cosmos.

Early life nutrition, epigenetics and programming of later life disease.

PubMed

Vickers, Mark H

2014-06-02

The global pandemic of obesity and type 2 diabetes is often causally linked to marked changes in diet and lifestyle; namely marked increases in dietary intakes of high energy diets and concomitant reductions in physical activity levels. However, less attention has been paid to the role of developmental plasticity and alterations in phenotypic outcomes resulting from altered environmental conditions during the early life period. Human and experimental animal studies have highlighted the link between alterations in the early life environment and increased risk of obesity and metabolic disorders in later life. This link is conceptualised as the developmental programming hypothesis whereby environmental influences during critical periods of developmental plasticity can elicit lifelong effects on the health and well-being of the offspring. In particular, the nutritional environment in which the fetus or infant develops influences the risk of metabolic disorders in offspring. The late onset of such diseases in response to earlier transient experiences has led to the suggestion that developmental programming may have an epigenetic component, as epigenetic marks such as DNA methylation or histone tail modifications could provide a persistent memory of earlier nutritional states. Moreover, evidence exists, at least from animal models, that such epigenetic programming should be viewed as a transgenerational phenomenon. However, the mechanisms by which early environmental insults can have long-term effects on offspring are relatively unclear. Thus far, these mechanisms include permanent structural changes to the organ caused by suboptimal levels of an important factor during a critical developmental period, changes in gene expression caused by epigenetic modifications (including DNA methylation, histone modification, and microRNA) and permanent changes in cellular ageing. A better understanding of the epigenetic basis of developmental programming and how these effects may be

Trans-generational Effects of Early Life Stress: The Role of Maternal Behavior

PubMed Central

Schmauss, Claudia; Lee-McDermott, Zoe; Medina, Liorimar Ramos

2014-01-01

Using a rodent paradigm of early life stress, infant maternal separation (IMS), we examined whether IMS-triggered behavioral and epigenetic phenotypes of the stress-susceptible mouse strain Balb/c are propagated across generations. These phenotypes include impaired emotional behavior and deficits in executive cognitive functions in adulthood, and they are associated with increased acetylation of histone H4K12 protein (acH4K12) in the forebrain neocortex. These behavioral and epigenetic phenotypes are transmitted to the first progeny of IMS Balb/c mothers, but not fathers, and cross-fostering experiments revealed that this transmission is triggered by maternal behavior and modulated by the genetic background of the pups. In the continued absence of the original stressor, this transmission fades in later progenies. An adolescent treatment that lowers the levels of acH4K12 in IMS Balb/c mice augments their emotional abnormality but abolishes their cognitive deficits. Conversely, a treatment that further elevates the levels of acH4K12 improved the emotional phenotype but had no effects on the cognitive deficits. Moreover, treatments that prevent the emergence of either emotional or cognitive deficits in the mother also prevent the establishment of such deficits in her offspring, indicating that trans-generational effects of early life stress can be prevented. PMID:24786242

Mrc1 Marks Early-Firing Origins and Coordinates Timing and Efficiency of Initiation in Fission Yeast ▿ †

PubMed Central

Hayano, Motoshi; Kanoh, Yutaka; Matsumoto, Seiji; Masai, Hisao

2011-01-01

How early- and late-firing origins are selected on eukaryotic chromosomes is largely unknown. Here, we show that Mrc1, a conserved factor required for stabilization of stalled replication forks, selectively binds to the early-firing origins in a manner independent of Cdc45 and Hsk1 kinase in the fission yeast Schizosaccharomyces pombe. In mrc1Δ cells (and in swi1Δ cells to some extent), efficiency of firing is stimulated, and its timing is advanced selectively at those origins that are normally bound by Mrc1. In contrast, the late or inefficient origins which are not bound by Mrc1 are not activated in mrc1Δ cells. The enhanced firing and precocious Cdc45 loading at Mrc1-bound early-firing origins are not observed in a checkpoint mutant of mrc1, suggesting that non-checkpoint function is involved in maintaining the normal program of early-firing origins. We propose that prefiring binding of Mrc1 is an important marker of early-firing origins which are precociously activated by the absence of this protein. PMID:21518960

Stardust: The Cosmic Seeds of Life

NASA Astrophysics Data System (ADS)

Kwok, Sun

How did life originate on Earth? For over 50 years, scientists believed that life was the result of chemistry involving simple molecules such as methane and ammonia cooking in a primordial soup. Recent space observations have revealed that old stars are capable of making very complex organic compounds. The stars then ejected the organics and spread them all over the Milky Way Galaxy. There is evidence that these organic dust particles actually reached the early Solar System. Through bombardments by comets and asteroids, the early Earth inherited significant amounts of star dust. Was the development of life assisted by the arrival of these extraterrestrial materials? In this book, we describe stunning discoveries in astronomy and solar system science over the last 10 years that resulted in a new perspective on the origin of life.

Acute mesenteric ischemia of arterial origin: importance of early revascularization.

PubMed

Plumereau, F; Mucci, S; Le Naoures, P; Finel, J B; Hamy, A

2015-02-01

The goal of our study was to show that survival was better when early revascularization was performed rather than gastrointestinal resection in the management of acute mesenteric ischemia of arterial origin. The reports of patients managed in our center between January 2005 and May 2012 for acute mesenteric ischemia of arterial origin were analyzed retrospectively. Data on clinical, laboratory and radiologic findings, the interval before treatment, the operative findings and the surgical procedures were collected. Follow-up information included the postoperative course, and mortality at 48 h, 30 days and 1 year, the latter being compared between patients undergoing revascularization versus gastrointestinal resection. Of 43 patients treated during this period, 20 had gastrointestinal lesions deemed to be beyond all therapeutic resources, 13 were treated with gastrointestinal resection without revascularization, while 10 underwent early revascularization. There were no statistically significant differences found in the extent of involvement between the two groups (P=0.22). Mortality at 48 h, 30 days and 1 year was 8% (n=1), 30% (n=4) and 68% (n=8) in patients who underwent enterectomy vs. 0% (n=0), 0% (n=0) and 10% (n=1) in patients who underwent revascularization procedures. The difference at 1 year was statistically significant (P=0.02). At 1 year, two patients in the revascularized group had a short bowel syndrome vs. one in the non-revascularized group. Acute mesenteric ischemia of arterial origin is associated with high morbidity and mortality. Optimal management should include early revascularization. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Astrobiology: Life on Earth (and Elsewhere?)

NASA Technical Reports Server (NTRS)

Des Marais, David J.

2016-01-01

Astrobiology investigates the origins, evolution and distribution of life in the universe. Scientists study how stellar systems and their planets can create planetary environments that sustain biospheres. They search for biosignatures, which are objects, substances and or patterns that indicate the presence of life. Studies of Earth's early biosphere enhance these search strategies and also provide key insights about our own origins.

The march from early life food sensitization to allergic disease: a systematic review and meta-analyses of birth cohort studies.

PubMed

Alduraywish, S A; Lodge, C J; Campbell, B; Allen, K J; Erbas, B; Lowe, A J; Dharmage, S C

2016-01-01

There is growing evidence for an increase in food allergies. The question of whether early life food sensitization, a primary step in food allergies, leads to other allergic disease is a controversial but important issue. Birth cohorts are an ideal design to answer this question. We aimed to systematically investigate and meta-analyse the evidence for associations between early food sensitization and allergic disease in birth cohorts. MEDLINE and SCOPUS databases were searched for birth cohorts that have investigated the association between food sensitization in the first 2 years and subsequent wheeze/asthma, eczema and/or allergic rhinitis. We performed meta-analyses using random-effects models to obtain pooled estimates, stratified by age group. The search yielded fifteen original articles representing thirteen cohorts. Early life food sensitization was associated with an increased risk of infantile eczema, childhood wheeze/asthma, eczema and allergic rhinitis and young adult asthma. Meta-analyses demonstrated that early life food sensitization is related to an increased risk of wheeze/asthma (pooled OR 2.9; 95% CI 2.0-4.0), eczema (pooled OR 2.7; 95% CI 1.7-4.4) and allergic rhinitis (pooled OR 3.1; 95% CI 1.9-4.9) from 4 to 8 years. Food sensitization in the first 2 years of life can identify children at high risk of subsequent allergic disease who may benefit from early life preventive strategies. However, due to potential residual confounding in the majority of studies combined with lack of follow-up into adolescence and adulthood, further research is needed. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Scientific and Religious Beliefs about the Origin of Life and Life after Death: Validation of a Scale

ERIC Educational Resources Information Center

Bautista, Jesús Silva; Escobar, Venazir Herrera; Miranda, Rodolfo Corona

2017-01-01

The variety of explanations to questions about the origin of life, life after death or about the role itself of being in the world are built on the rational reflection that integrates the ideology of human beings as well as less rational practices and more emotional ones than in the whole nourish what has been called "beliefs".…

The origin and early radiation of dinosaurs

NASA Astrophysics Data System (ADS)

Brusatte, Stephen L.; Nesbitt, Sterling J.; Irmis, Randall B.; Butler, Richard J.; Benton, Michael J.; Norell, Mark A.

2010-07-01

Dinosaurs were remarkably successful during the Mesozoic and one subgroup, birds, remain an important component of modern ecosystems. Although the extinction of non-avian dinosaurs at the end of the Cretaceous has been the subject of intense debate, comparatively little attention has been given to the origin and early evolution of dinosaurs during the Late Triassic and Early Jurassic, one of the most important evolutionary radiations in earth history. Our understanding of this keystone event has dramatically changed over the past 25 years, thanks to an influx of new fossil discoveries, reinterpretations of long-ignored specimens, and quantitative macroevolutionary analyses that synthesize anatomical and geological data. Here we provide an overview of the first 50 million years of dinosaur history, with a focus on the large-scale patterns that characterize the ascent of dinosaurs from a small, almost marginal group of reptiles in the Late Triassic to the preeminent terrestrial vertebrates of the Jurassic and Cretaceous. We provide both a biological and geological background for early dinosaur history. Dinosaurs are deeply nested among the archosaurian reptiles, diagnosed by only a small number of characters, and are subdivided into a number of major lineages. The first unequivocal dinosaurs are known from the late Carnian of South America, but the presence of their sister group in the Middle Triassic implies that dinosaurs possibly originated much earlier. The three major dinosaur lineages, theropods, sauropodomorphs, and ornithischians, are all known from the Triassic, when continents were joined into the supercontinent Pangaea and global climates were hot and arid. Although many researchers have long suggested that dinosaurs outcompeted other reptile groups during the Triassic, we argue that the ascent of dinosaurs was more of a matter of contingency and opportunism. Dinosaurs were overshadowed in most Late Triassic ecosystems by crocodile-line archosaurs and

Origins of life systems chemistry

NASA Astrophysics Data System (ADS)

Sutherland, J.

2015-10-01

By reconciling previously conflicting views about the origin of life - in which one or other cellular subsystem emerges first, and then 'invents' the others - a new modus operandi for its study is suggested. Guided by this, a cyanosulfidic protometabolism is uncovered which uses UV light and the stoichiometric reducing power of hydrogen sulfide to convert hydrogen cyanide, and a couple of other prebiotic feedstock molecules which can be derived therefrom, into nucleic acid, peptide and lipid building blocks. Copper plays several key roles in this chemistry, thus, for example, copper(I) catalysed cross coupling and copper(II) driven oxidative crosscoupling reactions generate key feedstock molecules. Geochemical scenarios consistent with this protometabolism are outlined. Finally, the transition of a system from the inanimate to the animate state is considered in the context of there being intermediate stages of partial 'aliveness'.

The origin of life: a problem of history, chemistry, and evolution.

PubMed

Ma, Wentao

2014-12-01

The origin of life is a field full of controversies, not only because of our vague understanding concerning the relevant issues, but also, perhaps more often, owing to our dim conceptual framework throughout the whole field. To improve this situation, an in-depth conceptual dissection is presented here. It is elucidated that, at its core, the origin of life has three aspects. The facts involved in the process are taken as the historical aspect, which is destined to be uncertain and often irrelevant to debate regarding details. The rules involved include two distinct aspects: chemical mechanisms operated in the whole process, while evolutionary mechanisms joined in only after the emergence of the first Darwinian entities - and then accounted for the subsequent buildup of complexity (this cannot be explained solely by natural selection). Basically, we can ask about the possibility of any assumed event in the origin of life: 'Is it evolutionarily plausible, chemically feasible, and historically likely?' Clues from any of the three aspects may be quite valuable in directing our explorations on the other two. This conceptual dissection provides a clearer context for the field, which may even be more useful than any sort of specific research. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.

The status of live viral vaccination in early life.

PubMed

Gans, Hayley A

2013-05-17

The need for neonatal vaccines is supported by the high disease burden during the first year of life particularly in the first month. Two-thirds of childhood deaths are attributable to infectious diseases of which viruses represent key pathogens. Many infectious diseases have the highest incidence, severity and mortality in the first months of life, and therefore early life vaccination would provide significant protection and life savings. For some childhood viral diseases successful vaccines exist, such as against measles, mumps, rubella, varicella, influenza poliovirus, and rotavirus, but their use in the first year particularly at birth is not yet practiced. Vaccines against other key pathogens continue to elude scientists such as against respiratory syncytial virus. The obstacles for early and neonatal vaccination are complex and include host factors, such as a developing immune system and the interference of passively acquired antibodies, as well vaccine-specific issues, such as optimal route of administration, titer and dosing requirements. Importantly, additional host and infrastructure barriers also present obstacles to neonatal vaccination in the developing world where morbidity and mortality rates are highest. This review will highlight the current live viral vaccines and their use in the first year of life, focusing on efficacy and entertaining the barriers that exist. It is important to understand the successes of current vaccines and use this knowledge to determine strategies that are successful in young infants and for the development of new vaccines for use in early life. Copyright © 2012 Elsevier Ltd. All rights reserved.

EARLY CRANIOFACIAL DEVELOPMENT: LIFE AMONG THE SIGNALS

EPA Science Inventory

Early Craniofacial Development: Life Among the Signals. Sid Hunter and Keith Ward. Reproductive Toxicology Division, NHEERL, US EPA, RTP, NC, 27711

Haloacetic acids (HAA) are chemicals formed during drinking water disinfection and present in finished tap water. Exposure o...

Prebiological evolution and the physics of the origin of life

NASA Astrophysics Data System (ADS)

Delaye, Luis; Lazcano, Antonio

2005-03-01

The basic tenet of the heterotrophic theory of the origin of life is that the maintenance and reproduction of the first living systems depended primarily on prebiotically synthesized organic molecules. It is unlikely that any single mechanism can account for the wide range of organic compounds that may have accumulated on the primitive Earth, suggesting that the prebiotic soup was formed by contributions from endogenous syntheses in reducing environments, metal sulphide-mediated synthesis in deep-sea vents, and exogenous sources such as comets, meteorites and interplanetary dust. The wide range of experimental conditions under which amino acids and nucleobases can be synthesized suggests that the abiotic syntheses of these monomers did not take place under a narrow range defined by highly selective reaction conditions, but rather under a wide variety of settings. The robustness of this type of chemistry is supported by the occurrence of most of these biochemical compounds in the Murchison meteorite. These results lend strong credence to the hypothesis that the emergence of life was the outcome of a long, but not necessarily slow, evolutionary processes. The origin of life may be best understood in terms of the dynamics and evolution of sets of chemical replicating entities. Whether such entities were enclosed within membranes is not yet clear, but given the prebiotic availability of amphiphilic compounds this may have well been the case. This scheme is not at odds with the theoretical models of self-organized emerging systems, but what is known of biology suggest that the essential traits of living systems could have not emerged in the absence of genetic material able to store, express and, upon replication, transmit to its progeny information capable of undergoing evolutionary change. How such genetic polymer first evolved is a central issue in origin-of-life studies.

Prebiological evolution and the physics of the origin of life.

PubMed

Delaye, Luis; Lazcano, Antonio

2005-03-01

The basic tenet of the heterotrophic theory of the origin of life is that the maintenance and reproduction of the first living systems depended primarily on prebiotically synthesized organic molecules. It is unlikely that any single mechanism can account for the wide range of organic compounds that may have accumulated on the primitive Earth, suggesting that the prebiotic soup was formed by contributions from endogenous syntheses in reducing environments, metal sulphide-mediated synthesis in deep-sea vents, and exogenous sources such as comets, meteorites and interplanetary dust. The wide range of experimental conditions under which amino acids and nucleobases can be synthesized suggests that the abiotic syntheses of these monomers did not take place under a narrow range defined by highly selective reaction conditions, but rather under a wide variety of settings. The robustness of this type of chemistry is supported by the occurrence of most of these biochemical compounds in the Murchison meteorite. These results lend strong credence to the hypothesis that the emergence of life was the outcome of a long, but not necessarily slow, evolutionary processes. The origin of life may be best understood in terms of the dynamics and evolution of sets of chemical replicating entities. Whether such entities were enclosed within membranes is not yet clear, but given the prebiotic availability of amphiphilic compounds this may have well been the case. This scheme is not at odds with the theoretical models of self-organized emerging systems, but what is known of biology suggest that the essential traits of living systems could have not emerged in the absence of genetic material able to store, express and, upon replication, transmit to its progeny information capable of undergoing evolutionary change. How such genetic polymer first evolved is a central issue in origin-of-life studies.

Early-Life Food Nutrition, Microbiota Maturation and Immune Development Shape Life-Long Health.

PubMed

Zhou, Xiaoli; Du, Lina; Shi, Ronghua; Chen, Zhidong; Zhou, Yiming; Li, Zongjie

2018-06-06

The current knowledge about early-life nutrition and environmental factors that affect the interaction between the symbiotic microbiota and the host immune system has demonstrated novel regulatory target for treating allergic diseases, autoimmune disorders and metabolic syndrome. Various kinds of food nutrients (such as dietary fiber, starch, polyphenols and proteins) can provide energy resources for both intestinal microbiota and the host. The indigestible food components are fermented by the indigenous gut microbiota to produce diverse metabolites, including short-chain fatty acids, bile acids and trimethylamine-N-oxide, which can regulate the host metabolized physiology, immunity homeostasis and health state. Therefore it is commonly believed early-life perturbation of the microbial community structure and the dietary nutrition interference on the child mucosal immunity contribute to the whole life susceptibility to chronic diseases. In all, the combined interrelationship between food ingredients nutrition, intestinal microbiota configurations and host system immunity provides new therapeutic targets to treat various kinds of pathogenic inflammations and chronic diseases.

An experimental demonstration that early-life competitive disadvantage accelerates telomere loss.

PubMed

Nettle, Daniel; Monaghan, Pat; Gillespie, Robert; Brilot, Ben; Bedford, Thomas; Bateson, Melissa

2015-01-07

Adverse experiences in early life can exert powerful delayed effects on adult survival and health. Telomere attrition is a potentially important mechanism in such effects. One source of early-life adversity is the stress caused by competitive disadvantage. Although previous avian experiments suggest that competitive disadvantage may accelerate telomere attrition, they do not clearly isolate the effects of competitive disadvantage from other sources of variation. Here, we present data from an experiment in European starlings (Sturnus vulgaris) that used cross-fostering to expose siblings to divergent early experience. Birds were assigned either to competitive advantage (being larger than their brood competitors) or competitive disadvantage (being smaller than their brood competitors) between days 3 and 12 post-hatching. Disadvantage did not affect weight gain, but it increased telomere attrition, leading to shorter telomere length in disadvantaged birds by day 12. There were no effects of disadvantage on oxidative damage as measured by plasma lipid peroxidation. We thus found strong evidence that early-life competitive disadvantage can accelerate telomere loss. This could lead to faster age-related deterioration and poorer health in later life.

Early feeding and early life housing conditions influence the response towards a noninfectious lung challenge in broilers.

PubMed

Simon, K; de Vries Reilingh, G; Bolhuis, J E; Kemp, B; Lammers, A

2015-09-01

Early life conditions such as feed and water availability immediately post hatch (PH) and housing conditions may influence immune development and therefore immune reactivity later in life. The current study addressed the consequences of a combination of these 2 early life conditions for immune reactivity, i.e., the specific antibody response towards a non-infectious lung challenge. Broiler chicks received feed and water either immediately p.h. or with a 72 h delay and were either reared in a floor or a cage system. At 4 weeks of age, chicks received either an intra-tracheally administered Escherichia coli lipopolysaccharide (LPS)/Human Serum Albumin (HUSA) challenge or a placebo, and antibody titers were measured up to day 14 after administration of the challenge. Chicks housed on the floor and which had a delayed access to feed p.h. showed the highest antibody titers against HuSA. These chicks also showed the strongest sickness response and poorest performance in response to the challenge, indicating that chicks with delayed access to feed might be more sensitive to an environment with higher antigenic pressure. In conclusion, results from the present study show that early life feeding strategy and housing conditions influence a chick's response to an immune challenge later in life. These 2 early life factors should therefore be taken into account when striving for a balance between disease resistance and performance in poultry. © 2015 Poultry Science Association Inc.

Early-life chemical exposures and risk of metabolic syndrome.

PubMed

De Long, Nicole E; Holloway, Alison C

2017-01-01

The global prevalence of obesity has been increasing at a staggering pace, with few indications of any decline, and is now one of the major public health challenges worldwide. While obesity and metabolic syndrome (MetS) have historically thought to be largely driven by increased caloric intake and lack of exercise, this is insufficient to account for the observed changes in disease trends. There is now increasing evidence to suggest that exposure to synthetic chemicals in our environment may also play a key role in the etiology and pathophysiology of metabolic diseases. Importantly, exposures occurring in early life (in utero and early childhood) may have a more profound effect on life-long risk of obesity and MetS. This narrative review explores the evidence linking early-life exposure to a suite of chemicals that are common contaminants associated with food production (pesticides; imidacloprid, chlorpyrifos, and glyphosate) and processing (acrylamide), in addition to chemicals ubiquitously found in our household goods (brominated flame retardants) and drinking water (heavy metals) and changes in key pathways important for the development of MetS and obesity.

Fluoride Exposure in Early Life as the Possible Root Cause of Disease In Later Life.

PubMed

Nakamoto, Tetsuo; Rawls, H Ralph

2018-05-15

Fluoride, one of the most celebrated ingredients for the prevention of dental caries in the 20th century, has also been controversial for its use in dentifrices and other applications. In the current review, we have concentrated primarily on early-life exposure to fluoride and how it may affect the various organs. The most recent controversial aspects of fluoride are related to toxicity of the developing brain and how it may possibly result in the decrease of intelligence quotient (IQ), autism, and calcification of the pineal gland. In addition, it has been reported to have possible effects on bone and thyroid glands. If nutritional stress is applied during a critical period of growth and development, the organ(s) and/or body will never recover once they pass through the critical period. For example, if animals are force-fed during experiments, they will simply get fat but never reach the normal size. Although early-life fluoride exposure causing fluorosis is well reported in the literature, the dental profession considers it primarily as an esthetic rather than a serious systemic problem. In the current review, we wanted to raise the possibility of future disease as a result of early-life exposure to fluoride. It is not currently known how fluoride will become a cause of future disease. Studies of other nutritional factors have shown that the effects of early nutritional stress are a cause of disease in later life.

Early-life adversity-induced long-term epigenetic programming associated with early onset of chronic physical aggression: Studies in humans and animals.

PubMed

Chistiakov, Dimitry A; Chekhonin, Vladimir P

2017-06-05

To examine whether chronic physical aggression (CPA) in adulthood can be epigenetically programmed early in life due to exposure to early-life adversity. Literature search of public databases such as PubMed/MEDLINE and Scopus. Children/adolescents susceptible for CPA and exposed to early-life abuse fail to efficiently cope with stress that in turn results in the development of CPA later in life. This phenomenon was observed in humans and animal models of aggression. The susceptibility to aggression is a complex trait that is regulated by the interaction between environmental and genetic factors. Epigenetic mechanisms mediate this interaction. Subjects exposed to stress early in life exhibited long-term epigenetic programming that can influence their behaviour in adulthood. This programming affects expression of many genes not only in the brain but also in other systems such as neuroendocrine and immune. The propensity to adult CPA behaviour in subjects experienced to early-life adversity is mediated by epigenetic programming that involves long-term systemic epigenetic alterations in a whole genome.

Early life family conflict, Social interactions and Carotid Artery Intima-Media Thickness in Adulthood

PubMed Central

John-Henderson, Neha A.; Kamarck, Thomas W.; Muldoon, Matthew F.; Manuck, Stephen B.

2015-01-01

Objective Conflict in early life family environments is known to affect psychosocial functioning and coping styles into adulthood and is reported to negatively affect access to psychosocial resources that are critical to the management of stress. However, it remains unknown whether early life family conflict similarly affects subclinical cardiovascular disease (CVD) in adulthood. We predicted that family conflict in early life would be associated with greater mean Intima-Media thickness (IMT), a subclinical marker of CVD risk, in adulthood. Methods Data were collected in a community sample of 503 adults (47.4 % male, mean age: 42.8 years [SD=7.3]). Associations between family conflict in early life with IMT (assessed using B-mode ultrasound) in adulthood were examined using regression analysis. We also tested for indirect effects of early life family conflict on mean IMT through ecological momentary assessment (EMA) reports of social interactions, diversity of social roles, and perceived social support. Results Linear regression analyses adjusted for demographics and physiological risk factors showed conflict in early life associated with greater mean IMT (β=0.08, t(447)=2.13, p=0.034, R2=0.46). Early life conflict was significantly related to diversity of social roles, perceived social support, and EMA reports of pleasant and social conflict interactions. Significant indirect effects of early life conflict on mean IMT were observed through fewer pleasant social interactions and more frequent social conflict interactions in adulthood (β = 0.001, 95% CI, 0.0001–0.0014 and β=0.001, 95% CI, 0.0002–0.0015, respectively). Conclusions These findings provide initial evidence that family conflict in early life heightens CVD risk in adulthood, in part by shaping the quality of adulthood social interactions. PMID:26809109

Early Life Family Conflict, Social Interactions, and Carotid Artery Intima-Media Thickness in Adulthood.

PubMed

John-Henderson, Neha A; Kamarck, Thomas W; Muldoon, Matthew F; Manuck, Stephen B

2016-04-01

Conflict in early life family environments is known to affect psychosocial functioning and coping styles into adulthood and is reported to negatively affect access to psychosocial resources that are critical to the management of stress. However, it remains unknown whether early life family conflict similarly affects subclinical cardiovascular disease (CVD) in adulthood. We predicted that family conflict in early life would be associated with greater mean intima-media thickness (IMT), a subclinical marker of CVD risk, in adulthood. Data were collected in a community sample of 503 adults (47.4 % male, mean [standard deviation] age = 42.8 [7.3] years). Associations between family conflict in early life with IMT (assessed using B-mode ultrasound) in adulthood were examined using regression analysis. We also tested for indirect effects of early life family conflict on mean IMT through ecological momentary assessment reports of social interactions, diversity of social roles, and perceived social support. Linear regression analyses adjusted for demographics and physiological risk factors showed conflict in early life associated with greater mean IMT (β = 0.08, t(447) = 2.13, p = .034, R = 0.46). Early life conflict was significantly related to diversity of social roles, perceived social support, and ecological momentary assessment reports of pleasant and social conflict interactions. Significant indirect effects of early life conflict on mean IMT were observed through fewer pleasant social interactions and more frequent social conflict interactions in adulthood (β = 0.001 [95% confidence interval = 0.0001-0.0014] and β = 0.001 [95% confidence interval = 0.0002-0.0015], respectively). These findings provide initial evidence that family conflict in early life heightens CVD risk in adulthood, in part by shaping the quality of adulthood social interactions.

Prebiological Synthesis Organic Matter and Origin of Life in Protoplanetary Disks

NASA Astrophysics Data System (ADS)

Snytnikov, V. N.

2017-05-01

Processes and conditions around new born Sun and possibly other young stars led to the origin of life in the circumstellar disc in a few million years. Than the circumsolar biosphere evolved to its current earth state. In agreement with the main results of the natural sciences and the theory of self-organization, several stages are necessary for the life to emerge on the Earth. Nowday we can specify "The cold prehistiry of the life", "RNA-world", "Preplanet biosphere", "Destructive biosphere", "Earth of bacteria".

Prevention of overweight and obesity in early life.

PubMed

Lanigan, Julie

2018-05-29

Childhood obesity is a serious challenge for public health. The problem begins early with most excess childhood weight gained before starting school. In 2016, the WHO estimated that 41 million children under 5 were overweight or obese. Once established, obesity is difficult to reverse, likely to persist into adult life and is associated with increased risk of CVD, type 2 diabetes and certain cancers. Preventing obesity is therefore of high importance. However, its development is multi-factorial and prevention is a complex challenge. Modifiable lifestyle behaviours such as diet and physical activity are the most well-known determinants of obesity. More recently, early-life factors have emerged as key influencers of obesity in childhood. Understanding risk factors and how they interact is important to inform interventions that aim to prevent obesity in early childhood. Available evidence supports multi-component interventions as effective in obesity prevention. However, relatively few interventions are available in the UK and only one, TrimTots, has been evaluated in randomised controlled trials and shown to be effective at reducing obesity risk in preschool children (age 1-5 years). BMI was lower in children immediately after completing TrimTots compared with waiting list controls and this effect was sustained at long-term follow-up, 2 years after completion. Developing and evaluating complex interventions for obesity prevention is a challenge for clinicians and researchers. In addition, parents encounter barriers engaging with interventions. This review considers early-life risk factors for obesity, highlights evidence for preventative interventions and discusses barriers and facilitators to their success.

Early-life stress and reproductive cost: A two-hit developmental model of accelerated aging?

PubMed

Shalev, Idan; Belsky, Jay

2016-05-01

Two seemingly independent bodies of research suggest a two-hit model of accelerated aging, one highlighting early-life stress and the other reproduction. The first, informed by developmental models of early-life stress, highlights reduced longevity effects of early adversity on telomere erosion, whereas the second, informed by evolutionary theories of aging, highlights such effects with regard to reproductive cost (in females). The fact that both early-life adversity and reproductive effort are associated with shorter telomeres and increased oxidative stress raises the prospect, consistent with life-history theory, that these two theoretical frameworks currently informing much research are tapping into the same evolutionary-developmental process of increased senescence and reduced longevity. Here we propose a mechanistic view of a two-hit model of accelerated aging in human females through (a) early-life adversity and (b) early reproduction, via a process of telomere erosion, while highlighting mediating biological embedding mechanisms that might link these two developmental aging processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Social anxiety and negative early life events in university students.

PubMed

Binelli, Cynthia; Ortiz, Ana; Muñiz, Armando; Gelabert, Estel; Ferraz, Liliana; S Filho, Alaor; Crippa, José Alexandre S; Nardi, Antonio E; Subirà, Susana; Martín-Santos, Rocío

2012-06-01

There is substantial evidence regarding the impact of negative life events during childhood on the aetiology of psychiatric disorders. We examined the association between negative early life events and social anxiety in a sample of 571 Spanish University students. In a cross-sectional survey conducted in 2007, we collected data through a semistructured questionnaire of sociodemographic variables, personal and family psychiatric history, and substance abuse. We assessed the five early negative life events: (i) the loss of someone close, (ii) emotional abuse, (iii) physical abuse, (iv) family violence, and (v) sexual abuse. All participants completed the Liebowitz Social Anxiety Scale. Mean (SD) age was 21 (4.5), 75% female, LSAS score was 40 (DP = 22), 14.2% had a psychiatric family history and 50.6% had negative life events during childhood. Linear regression analyses, after controlling for age, gender, and family psychiatric history, showed a positive association between family violence and social score (p = 0.03). None of the remaining stressors produced a significant increase in LSAS score (p > 0.05). University students with high levels of social anxiety presented higher prevalence of negative early life events. Thus, childhood family violence could be a risk factor for social anxiety in such a population.

Early Life Nutrition and Energy Balance Disorders in Offspring in Later Life

PubMed Central

Reynolds, Clare M.; Gray, Clint; Li, Minglan; Segovia, Stephanie A.; Vickers, Mark H.

2015-01-01

The global pandemic of obesity and type 2 diabetes is often causally linked to changes in diet and lifestyle; namely increased intake of calorically dense foods and concomitant reductions in physical activity. Epidemiological studies in humans and controlled animal intervention studies have now shown that nutritional programming in early periods of life is a phenomenon that affects metabolic and physiological functions throughout life. This link is conceptualised as the developmental programming hypothesis whereby environmental influences during critical periods of developmental plasticity can elicit lifelong effects on the health and well-being of the offspring. The mechanisms by which early environmental insults can have long-term effects on offspring remain poorly defined. However there is evidence from intervention studies which indicate altered wiring of the hypothalamic circuits that regulate energy balance and epigenetic effects including altered DNA methylation of key adipokines including leptin. Studies that elucidate the mechanisms behind these associations will have a positive impact on the health of future populations and adopting a life course perspective will allow identification of phenotype and markers of risk earlier, with the possibility of nutritional and other lifestyle interventions that have obvious implications for prevention of non-communicable diseases. PMID:26402696

Planetary Perspective on Life on Early Mars and the Early Earth

NASA Technical Reports Server (NTRS)

Sleep, Norman H.; Zahnle, Kevin

1996-01-01

Impacts of asteroids and comets posed a major hazard to the continuous existence of early life on Mars as on the Earth. The chief danger was presented by globally distributed ejecta, which for very large impacts takes the form of transient thick rock vapor atmospheres; both planets suffered such impacts repeatedly. The exposed surface on both planets was sterilized when it was quickly heated to the temperature of condensed rock vapor by radiation and rock rain. Shallow water bodies were quickly evaporated and sterilized. Any surviving life must have been either in deep water or well below the surface.

Amyloid and the origin of life: self-replicating catalytic amyloids as prebiotic informational and protometabolic entities.

PubMed

Maury, Carl Peter J

2018-05-01

A crucial stage in the origin of life was the emergence of the first molecular entity that was able to replicate, transmit information, and evolve on the early Earth. The amyloid world hypothesis posits that in the pre-RNA era, information processing was based on catalytic amyloids. The self-assembly of short peptides into β-sheet amyloid conformers leads to extraordinary structural stability and novel multifunctionality that cannot be achieved by the corresponding nonaggregated peptides. The new functions include self-replication, catalytic activities, and information transfer. The environmentally sensitive template-assisted replication cycles generate a variety of amyloid polymorphs on which evolutive forces can act, and the fibrillar assemblies can serve as scaffolds for the amyloids themselves and for ribonucleotides proteins and lipids. The role of amyloid in the putative transition process from an amyloid world to an amyloid-RNA-protein world is not limited to scaffolding and protection: the interactions between amyloid, RNA, and protein are both complex and cooperative, and the amyloid assemblages can function as protometabolic entities catalyzing the formation of simple metabolite precursors. The emergence of a pristine amyloid-based in-put sensitive, chiroselective, and error correcting information-processing system, and the evolvement of mutualistic networks were, arguably, of essential importance in the dynamic processes that led to increased complexity, organization, compartmentalization, and, eventually, the origin of life.

What Teachers Should Know about the Evolution-Intentional Design Debate on the Origin of Life.

ERIC Educational Resources Information Center

Brekke, Stewart E.

This paper discusses the beginning of life on Earth, the formation of life forms, evolution, and the origin of life. The paper suggests that how life first appeared on earth is not known and may never be known. (YDS)

Promoting Career Development and Life Design in the Early Years of a Person's Life

ERIC Educational Resources Information Center

Maree, Jacobus G.

2018-01-01

The article discusses the changing world of work and the attendant uncertainty and loss of work-life identity. Little research has been done on career development and life design in the early years of a person's life, especially in developing countries characterized by disadvantage. The underlying theoretical models of career development are…

An experimental demonstration that early-life competitive disadvantage accelerates telomere loss

PubMed Central

Nettle, Daniel; Monaghan, Pat; Gillespie, Robert; Brilot, Ben; Bedford, Thomas; Bateson, Melissa

2015-01-01

Adverse experiences in early life can exert powerful delayed effects on adult survival and health. Telomere attrition is a potentially important mechanism in such effects. One source of early-life adversity is the stress caused by competitive disadvantage. Although previous avian experiments suggest that competitive disadvantage may accelerate telomere attrition, they do not clearly isolate the effects of competitive disadvantage from other sources of variation. Here, we present data from an experiment in European starlings (Sturnus vulgaris) that used cross-fostering to expose siblings to divergent early experience. Birds were assigned either to competitive advantage (being larger than their brood competitors) or competitive disadvantage (being smaller than their brood competitors) between days 3 and 12 post-hatching. Disadvantage did not affect weight gain, but it increased telomere attrition, leading to shorter telomere length in disadvantaged birds by day 12. There were no effects of disadvantage on oxidative damage as measured by plasma lipid peroxidation. We thus found strong evidence that early-life competitive disadvantage can accelerate telomere loss. This could lead to faster age-related deterioration and poorer health in later life. PMID:25411450

The origin of life in a cosmic context

NASA Technical Reports Server (NTRS)

Sagan, C.

1974-01-01

It is shown that there is at present no aspect of contemporary biology where the contingent can be distinguished from the necessary, or the evolutionary accident from the biological sine qua non; and no amount of terrestrial experimentation alone is likely to make such distinctions possible. Hence, biology suffers from a deadening parochialism, much like the physics of falling bodies before Newton showed that the same laws applied to the motion of apples in England and to the planets about the sun. The deparochialization of biology can only come in the same way and must therefore await the search for extraterrestrial life. It is in this sense that the significance of explorations of the planets and their satellites, asteroids, comets, and the interplanetary medium for the origin of life is assessed.

Theory of the Origin, Evolution, and Nature of Life

PubMed Central

Andrulis, Erik D.

2011-01-01

Life is an inordinately complex unsolved puzzle. Despite significant theoretical progress, experimental anomalies, paradoxes, and enigmas have revealed paradigmatic limitations. Thus, the advancement of scientific understanding requires new models that resolve fundamental problems. Here, I present a theoretical framework that economically fits evidence accumulated from examinations of life. This theory is based upon a straightforward and non-mathematical core model and proposes unique yet empirically consistent explanations for major phenomena including, but not limited to, quantum gravity, phase transitions of water, why living systems are predominantly CHNOPS (carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur), homochirality of sugars and amino acids, homeoviscous adaptation, triplet code, and DNA mutations. The theoretical framework unifies the macrocosmic and microcosmic realms, validates predicted laws of nature, and solves the puzzle of the origin and evolution of cellular life in the universe. PMID:25382118

Probiotics in early life: a preventative and treatment approach.

PubMed

Hashemi, Ashkan; Villa, Christopher R; Comelli, Elena M

2016-04-01

Microbial colonization of the infant gut plays a key role in immunological and metabolic pathways impacting human health. Since the maturation of the gut microbiota coincides with early life development, failure to develop a health compatible microbiota composition may result in pathology and disease in later life. Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. Maternal transfer of microorganisms is possible during pregnancy and lactation, and the mother's diet and microbiota can influence that of her offspring. Furthermore, pre-term birth, Caesarean section birth, formula feeding, antibiotic use, and malnutrition have been linked to dysbiosis, which in turn is associated with several pathologies such as necrotizing enterocolitis, inflammatory bowel diseases, antibiotic associated diarrhea, colic, and allergies. Thus, early life should represent a preferred stage of life for probiotic interventions. In this context, they could be regarded as a means to 'program' the individual for health maintenance, in order to prevent pathologies associated with dysbiosis. In order to elucidate the mechanisms underlying the benefits of probiotic administration, pre-clinical studies have been conducted and found an array of positive results such as improved microbial composition, intestinal maturation, decreased pathogenic load and infections, and improved immune response. Moreover, specific probiotic strains administered during the perinatal period have shown promise in attenuating severity of necrotizing enterocolitis. The mechanisms elucidated suggest that probiotic interventions in early life can be envisaged for disease prevention in both healthy offspring and offspring at risk of chronic disease.

Early-late life trade-offs and the evolution of ageing in the wild.

PubMed

Lemaître, Jean-François; Berger, Vérane; Bonenfant, Christophe; Douhard, Mathieu; Gamelon, Marlène; Plard, Floriane; Gaillard, Jean-Michel

2015-05-07

Empirical evidence for declines in fitness components (survival and reproductive performance) with age has recently accumulated in wild populations, highlighting that the process of senescence is nearly ubiquitous in the living world. Senescence patterns are highly variable among species and current evolutionary theories of ageing propose that such variation can be accounted for by differences in allocation to growth and reproduction during early life. Here, we compiled 26 studies of free-ranging vertebrate populations that explicitly tested for a trade-off between performance in early and late life. Our review brings overall support for the presence of early-late life trade-offs, suggesting that the limitation of available resources leads individuals to trade somatic maintenance later in life for high allocation to reproduction early in life. We discuss our results in the light of two closely related theories of ageing-the disposable soma and the antagonistic pleiotropy theories-and propose that the principle of energy allocation roots the ageing process in the evolution of life-history strategies. Finally, we outline research topics that should be investigated in future studies, including the importance of natal environmental conditions in the study of trade-offs between early- and late-life performance and the evolution of sex-differences in ageing patterns. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Early-Life Intelligence Predicts Midlife Biological Age

PubMed Central

Caspi, Avshalom; Belsky, Daniel W.; Harrington, Honalee; Houts, Renate; Israel, Salomon; Levine, Morgan E.; Sugden, Karen; Williams, Benjamin; Poulton, Richie; Moffitt, Terrie E.

2016-01-01

Objectives: Early-life intelligence has been shown to predict multiple causes of death in populations around the world. This finding suggests that intelligence might influence mortality through its effects on a general process of physiological deterioration (i.e., individual variation in “biological age”). We examined whether intelligence could predict measures of aging at midlife before the onset of most age-related disease. Methods: We tested whether intelligence assessed in early childhood, middle childhood, and midlife predicted midlife biological age in members of the Dunedin Study, a population-representative birth cohort. Results: Lower intelligence predicted more advanced biological age at midlife as captured by perceived facial age, a 10-biomarker algorithm based on data from the National Health and Nutrition Examination Survey (NHANES), and Framingham heart age (r = 0.1–0.2). Correlations between intelligence and telomere length were less consistent. The associations between intelligence and biological age were not explained by differences in childhood health or parental socioeconomic status, and intelligence remained a significant predictor of biological age even when intelligence was assessed before Study members began their formal schooling. Discussion: These results suggest that accelerated aging may serve as one of the factors linking low early-life intelligence to increased rates of morbidity and mortality. PMID:26014827

Impact of early life adversity on EMG stress reactivity of the trapezius muscle.

PubMed

Luijcks, Rosan; Vossen, Catherine J; Roggeveen, Suzanne; van Os, Jim; Hermens, Hermie J; Lousberg, Richel

2016-09-01

Human and animal research indicates that exposure to early life adversity increases stress sensitivity later in life. While behavioral markers of adversity-induced stress sensitivity have been suggested, physiological markers remain to be elucidated. It is known that trapezius muscle activity increases during stressful situations. The present study examined to what degree early life adverse events experienced during early childhood (0-11 years) and adolescence (12-17 years) moderate experimentally induced electromyographic (EMG) stress activity of the trapezius muscles, in an experimental setting. In a general population sample (n = 115), an anticipatory stress effect was generated by presenting a single unpredictable and uncontrollable electrical painful stimulus at t = 3 minutes. Subjects were unaware of the precise moment of stimulus delivery and its intensity level. Linear and nonlinear time courses in EMG activity were modeled using multilevel analysis. The study protocol included 2 experimental sessions (t = 0 and t = 6 months) allowing for examination of reliability.Results show that EMG stress reactivity during the stress paradigm was consistently stronger in people with higher levels of early life adverse events; early childhood adversity had a stronger moderating effect than adolescent adversity. The impact of early life adversity on EMG stress reactivity may represent a reliable facet that can be used in both clinical and nonclinical studies.

Early life permethrin exposure leads to hypervitaminosis D, nitric oxide and catecholamines impairment.

PubMed

Fedeli, Donatella; Carloni, Manuel; Nasuti, Cinzia; Gambini, Anna; Scocco, Vitangelo; Gabbianelli, Rosita

2013-09-01

The aim of this study is to gain more knowledge on the impact of early life pesticide exposure on premature aging. The effect of a low dose of the insecticide permethrin administered to rats during early life (1/50 LD50, from 6th to 21st day of life) was analyzed by measuring some metabolites in plasma and urine of 500-day-old animals. Significant differences in early life treated rats compared to the control group were found in the plasma levels of Ca(++), Na(+), 25-hydroxy-vitamin D, adrenaline, noradrenaline, nitric oxide, cholesterol and urea while in urine only Na(+) content was different. These results add information on the impact of permethrin during the neonatal period, supporting the evidence that early life environmental exposure to xenobiotics has long-term effects, inducing modifications in adulthood that can be revealed by the analysis of some macroelements, metabolites and catecholamines in plasma, when rats are 500 days old. Copyright © 2013 Elsevier Inc. All rights reserved.

The interplay of early-life stress, nutrition, and immune activation programs adult hippocampal structure and function

PubMed Central

Hoeijmakers, Lianne; Lucassen, Paul J.; Korosi, Aniko

2015-01-01

Early-life adversity increases the vulnerability to develop psychopathologies and cognitive decline later in life. This association is supported by clinical and preclinical studies. Remarkably, experiences of stress during this sensitive period, in the form of abuse or neglect but also early malnutrition or an early immune challenge elicit very similar long-term effects on brain structure and function. During early-life, both exogenous factors like nutrition and maternal care, as well as endogenous modulators, including stress hormones and mediator of immunological activity affect brain development. The interplay of these key elements and their underlying molecular mechanisms are not fully understood. We discuss here the hypothesis that exposure to early-life adversity (specifically stress, under/malnutrition and infection) leads to life-long alterations in hippocampal-related cognitive functions, at least partly via changes in hippocampal neurogenesis. We further discuss how these different key elements of the early-life environment interact and affect one another and suggest that it is a synergistic action of these elements that shapes cognition throughout life. Finally, we consider different intervention studies aiming to prevent these early-life adversity induced consequences. The emerging evidence for the intriguing interplay of stress, nutrition, and immune activity in the early-life programming calls for a more in depth understanding of the interaction of these elements and the underlying mechanisms. This knowledge will help to develop intervention strategies that will converge on a more complete set of changes induced by early-life adversity. PMID:25620909

EARLY LIFE RISKS, ANTISOCIAL TENDENCIES, AND PRETEEN DELINQUENCY.

PubMed

Staff, Jeremy; Whichard, Corey; Siennick, Sonja; Maggs, Jennifer

2015-11-01

Early age-of-onset delinquency and substance use confer a major risk for continued criminality, alcohol and drug abuse, and other serious difficulties throughout the life course. Our objective is to examine the developmental roots of preteen delinquency and substance use. Using nationally representative longitudinal data from the UK Millennium Cohort Study ( n = 13,221), we examine the influence of early childhood developmental and family risks on latent pathways of antisocial tendencies from ages 3 to 7, and the influence of those pathways on property crime and substance use by age 11. We identified a normative, non-antisocial pathway; a pathway marked by oppositional behavior and fighting; a pathway marked by impulsivity and inattention; and a rare pathway characterized by a wide range of antisocial tendencies. Children with developmental and family risks that emerged by age 3-specifically difficult infant temperament, low cognitive ability, weak parental closeness, and disadvantaged family background-face increased odds of antisocial tendencies. There is minimal overlap between the risk factors for early antisocial tendencies and those for preteen delinquency. Children on an antisocial pathway are more likely to engage in preteen delinquency and substance use by age 11, even after accounting for early life risk factors.

EARLY LIFE RISKS, ANTISOCIAL TENDENCIES, AND PRETEEN DELINQUENCY*

PubMed Central

Staff, Jeremy; Whichard, Corey; Siennick, Sonja; Maggs, Jennifer

2015-01-01

Early age-of-onset delinquency and substance use confer a major risk for continued criminality, alcohol and drug abuse, and other serious difficulties throughout the life course. Our objective is to examine the developmental roots of preteen delinquency and substance use. Using nationally representative longitudinal data from the UK Millennium Cohort Study (n = 13,221), we examine the influence of early childhood developmental and family risks on latent pathways of antisocial tendencies from ages 3 to 7, and the influence of those pathways on property crime and substance use by age 11. We identified a normative, non-antisocial pathway; a pathway marked by oppositional behavior and fighting; a pathway marked by impulsivity and inattention; and a rare pathway characterized by a wide range of antisocial tendencies. Children with developmental and family risks that emerged by age 3—specifically difficult infant temperament, low cognitive ability, weak parental closeness, and disadvantaged family background—face increased odds of antisocial tendencies. There is minimal overlap between the risk factors for early antisocial tendencies and those for preteen delinquency. Children on an antisocial pathway are more likely to engage in preteen delinquency and substance use by age 11, even after accounting for early life risk factors. PMID:26900167

Attentional avoidance of fearful facial expressions following early life stress is associated with impaired social functioning.

PubMed

Humphreys, Kathryn L; Kircanski, Katharina; Colich, Natalie L; Gotlib, Ian H

2016-10-01

Early life stress is associated with poorer social functioning. Attentional biases in response to threat-related cues, linked to both early experience and psychopathology, may explain this association. To date, however, no study has examined attentional biases to fearful facial expressions as a function of early life stress or examined these biases as a potential mediator of the relation between early life stress and social problems. In a sample of 154 children (ages 9-13 years) we examined the associations among interpersonal early life stressors (i.e., birth through age 6 years), attentional biases to emotional facial expressions using a dot-probe task, and social functioning on the Child Behavior Checklist. High levels of early life stress were associated with both greater levels of social problems and an attentional bias away from fearful facial expressions, even after accounting for stressors occurring in later childhood. No biases were found for happy or sad facial expressions as a function of early life stress. Finally, attentional biases to fearful faces mediated the association between early life stress and social problems. Attentional avoidance of fearful facial expressions, evidenced by a bias away from these stimuli, may be a developmental response to early adversity and link the experience of early life stress to poorer social functioning. © 2016 Association for Child and Adolescent Mental Health.

FKBP5 genotype interacts with early life trauma to predict heavy drinking in college students.

PubMed

Lieberman, Richard; Armeli, Stephen; Scott, Denise M; Kranzler, Henry R; Tennen, Howard; Covault, Jonathan

2016-09-01

Alcohol use disorder (AUD) is debilitating and costly. Identification and better understanding of risk factors influencing the development of AUD remain a research priority. Although early life exposure to trauma increases the risk of adulthood psychiatric disorders, including AUD, many individuals exposed to early life trauma do not develop psychopathology. Underlying genetic factors may contribute to differential sensitivity to trauma experienced in childhood. The hypothalamic-pituitary-adrenal (HPA) axis is susceptible to long-lasting changes in function following childhood trauma. Functional genetic variation within FKBP5, a gene encoding a modulator of HPA axis function, is associated with the development of psychiatric symptoms in adulthood, particularly among individuals exposed to trauma early in life. In the current study, we examined interactions between self-reported early life trauma, past-year life stress, past-year trauma, and a single nucleotide polymorphism (rs1360780) in FKBP5 on heavy alcohol consumption in a sample of 1,845 college students from two university settings. Although we found no effect of early life trauma on heavy drinking in rs1360780*T-allele carriers, rs1360780*C homozygotes exposed to early life trauma had a lower probability of heavy drinking compared to rs1360780*C homozygotes not exposed to early life trauma (P < 0.01). The absence of an interaction between either current life stress or past-year trauma, and FKBP5 genotype on heavy drinking suggests that there exists a developmental period of susceptibility to stress that is moderated by FKBP5 genotype. These findings implicate interactive effects of early life trauma and FKBP5 genetic variation on heavy drinking. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Low-grade disease activity in early life precedes childhood asthma and allergy.

PubMed

Chawes, Bo Lund Krogsgaard

2016-08-01

Asthma and allergies are today the most common chronic diseases in children and the leading causes of school absences, chronic medication usage, emergency department visits and hospitalizations, which affect all members of the family and represent a significant societal and scientific challenge. These highly prevalent disorders are thought to originate from immune distortion in early childhood, but the etiology and heterogeneity of the disease mechanisms are not understood, which hampers preventive initiatives and makes treatment inadequate. The objective of this thesis is to investigate the presence of an early life disease activity prior to clinical symptoms to understand the anteceding pathophysiological steps towards childhood asthma and allergy. The thesis is built on seven studies from the Copenhagen Prospective Studies on Asthma in Childhood (COPSAC2000) birth cohort examining biomarkers of disease activity in 411 asymptomatic neonates in cord blood (I-II), urine (III), exhaled breath (IV-V) and infant lung function (VI-VII) in relation to the subsequent development of asthma and allergy during the first seven years of life. In papers I-II, we studied cord blood chemokines and 25(OH)-vitamin D, which represent a proxy of the inborn immature immune system, the intrauterine milieu, and the maternal immune health during pregnancy. High levels of the Th2-related chemokine CCL22 and high CCL22/CXCL11 ratio were positively correlated with total IgE level during preschool age (II). This suggests an inborn Th2 skewing of the immune system in healthy newborns subsequently developing elevated total IgE antibodies, which is considered to increase the risk of asthma and allergies later in life. Additionally, deficient cord blood 25(OH)-vitamin D levels were associated with a 2.7-fold increased risk of recurrent wheeze at age 0-7 years (I). Together, these findings support the concept that early life immune programming in the pre-symptomatic era plays an essential role

The possibility of life on Mars during a water-rich past

NASA Technical Reports Server (NTRS)

Mckay, C. P.; Mancinelli, R. L.; Stoker, C. R.; Wharton, R. A., Jr.

1992-01-01

Geomorphological evidence for past liquid water on Mars implies an early, warmer, epoch. In this review we compare this early warm environment to the first Gyr of Earth's history, the time within which we know life originated. We consider the key question about early Mars from the biological standpoint. How long was liquid water present? The range of answers encompasses the time interval for the origin of life on Earth. We use studies of early life on Earth as a guide, albeit a limited one, to the possible forms of evidence for past life on Mars. Presumptive evidence for microbial life on early Earth are stromatolites, layered deposits produced by microorganisms binding and trapping sediment. A search for fossils might be fruitful at sites on Mars that contained standing bodies of water over long periods of time. The ice-covered lakes of the dry valleys of Antarctica may provide analogs to the ultimate lakes on Mars as the surface pressure fell with a concomitant decrease in surface temperatures.

Kindling of Life Stress in Bipolar Disorder: Effects of Early Adversity.

PubMed

Shapero, Benjamin G; Weiss, Rachel B; Burke, Taylor A; Boland, Elaine M; Abramson, Lyn Y; Alloy, Lauren B

2017-05-01

Most theoretical frameworks regarding the role of life stress in bipolar disorders (BD) do not incorporate the possibility of a changing relationship between psychosocial context and episode initiation across the course of the disorder. The kindling hypothesis theorizes that over the longitudinal course of recurrent affective disorders, the relationship between major life stressors and episode initiation declines (Post, 1992). The present study aimed to test an extension of the kindling hypothesis in BD by examining the effect of early life adversity on the relationship between proximal life events and prospectively assessed mood episodes. Data from 145 bipolar participants (59.3% female, 75.2% Caucasian, and mean age of 20.19 years; SD = 1.75 years) were collected as part of the Temple-Wisconsin Longitudinal Investigation of Bipolar Spectrum Project (112 Bipolar II; 33 Cyclothymic disorder). Participants completed a self-report measure of early adversity at baseline and interview-assessed mood episodes and life events at regular 4-month follow-ups. Results indicate that early childhood adversity sensitized bipolar participants to the effects of recent stressors only for depressive episodes and not hypomanic episodes within BD. This was particularly the case with minor negative events. The current study extends prior research examining the kindling model in BD using a methodologically rigorous assessment of life stressors and mood episode occurrence. Clinicians should assess experiences of early adversity in individuals with BD as it may impact reactivity to developing depressive episodes in response to future stressors. Copyright © 2017. Published by Elsevier Ltd.

Life Satisfaction in Early Adolescence: Personal, Neighborhood, School, Family, and Peer Influences

ERIC Educational Resources Information Center

Oberle, Eva; Schonert-Reichl, Kimberly A.; Zumbo, Bruno D.

2011-01-01

Drawing from an ecological assets framework as well as research and theory on positive youth development, this study examined the relationship of early adolescents' satisfaction with life to trait optimism and assets representing the social contexts in which early adolescents spend most of their time. Self-reports of satisfaction with life,…

Early South Americans Cranial Morphological Variation and the Origin of American Biological Diversity

PubMed Central

Hubbe, Alex; Neves, Walter A.

2015-01-01

Recent South Americans have been described as presenting high regional cranial morphological diversity when compared to other regions of the world. This high diversity is in accordance with linguistic and some of the molecular data currently available for the continent, but the origin of this diversity has not been satisfactorily explained yet. Here we explore if this high morphological variation was already present among early groups in South America, in order to refine our knowledge about the timing and origins of the modern morphological diversity. Between-group (Fst estimates) and within-group variances (trace of within-group covariance matrix) of the only two early American population samples available to date (Lagoa Santa and Sabana de Bogotá) were estimated based on linear craniometric measurements and compared to modern human cranial series representing six regions of the world, including the Americas. The results show that early Americans present moderate within-group diversity, falling well within the range of modern human groups, despite representing almost three thousand years of human occupation. The between-group variance apportionment is very low between early Americans, but is high among recent South American groups, who show values similar to the ones observed on a global scale. Although limited to only two early South American series, these results suggest that the high morphological diversity of native South Americans was not present among the first human groups arriving in the continent and must have originated during the Middle Holocene, possibly due to the arrival of new morphological diversity coming from Asia during the Holocene. PMID:26465141

The die is cast: arsenic exposure in early life and disease susceptibility.

PubMed

Thomas, David J

2013-12-16

Early life exposure to arsenic in humans and mice produces similar patterns of disease in later life. Given the long interval between exposure and effect, epigenetic effects of early life exposure to arsenic may account for the development and progression of disease in both species. Mode of action and dosimetric studies in the mouse may help assess the role of age at exposure as a factor in susceptibility to the toxic and carcinogenic effects of arsenic in humans.

The Changing Life Space of Early Adolescence.

ERIC Educational Resources Information Center

Larson, Reed, Ed.; Richards, Maryse, H., Ed.

1989-01-01

Eight papers are presented that describe the daily experience of White American children in grades 5 through 9. Each paper examines a segment of daily activity (e.g., schoolwork, talking, sports) and the associated affective states for 401 participants to provide a picture of the life space of early adolescence. (SLD)

Solar UV Radiation and the Origin of Life On Earth

NASA Technical Reports Server (NTRS)

Heap, S. R.; Lanz, T.; Hubeny, I.; Gaidos, E.; Oegerle, William R. (Technical Monitor)

2002-01-01

We have embarked on a program aimed at understanding the atmosphere of the early Earth, because of its importance as a greenhouse, radiation shield and energy source for life. Here, we give a progress report on the first phase of this program to establish the UV radiation from the early Sun. We have obtained ultraviolet spectra (STIS, FUSE, EUVE) of carefully selected nearby, young solar-type stars, which act as surrogates for the early Sun We are making detailed non-LTE analyses of the spectra and constructing models of their photospheres + chromospheres. Once validated, these models will allow us to extrapolate our theoretical spectra to other metallicities and to unobserved spectral regions.

Examination of associations between early life victimisation and alcohol's harm from others.

PubMed

Kaplan, Lauren M; Greenfield, Thomas K; Karriker-Jaffe, Katherine J

2018-03-01

Study aims were to examine: (i) how physical and sexual victimisation in early life are associated with alcohol's harm from others; and (ii) whether respondents' current drinking is a mediator of the association between early life victimisation and alcohol's harm from others among men and women. Data were from national computer-assisted telephone interviews, using the landline sample (3335 men and 3520 women ages ≥18) from the 2010 US National Alcohol Survey. Harms from someone else's drinking included family/marital problems, financial troubles, assault and vandalism in the past 12 months. Victimisation was measured with severe physical abuse or sexual assault before age 18. Severe physical or sexual victimisation before age 18 was reported by 3.4% of men and 8.1% of women. Significantly more men (5.2%) than women (2.4%) reported assault by other drinkers, and significantly more women reported family/marital (5.3%) and financial problems (2.8%) than did men (2.6 and 1% respectively). Severe early life victimisation was robustly associated with a greater likelihood of experiencing past-year harms from other drinkers for both men and women. Men's drinking partially mediated associations between early life victimisation and recent assaults and vandalism by other drinkers. Early life victimisation may increase risk of harms from someone else's drinking. Health services and interventions that screen for histories of victimisation may help decrease risk of later harms from others' drinking. Reductions in drinking among men with histories of victimisation also could help reduce their exposure to such harms. [Kaplan LM, Greenfield TK, Karriker-Jaffe KJ. Examination of associations between early life victimisation and alcohol's harm from others. © 2017 Australasian Professional Society on Alcohol and other Drugs.

Natural selection and sex differences in morbidity and mortality in early life.

PubMed

Wells, J C

2000-01-07

Both morbidity and mortality are consistently reported to be higher in males than in females in early life, but no explanation for these findings has been offered. This paper argues that the sex difference in early vulnerability can be attributed to the natural selection of optimal maternal strategies for maximizing lifetime reproductive success, as modelled previously by Trivers and Willard. These authors theorized that males and females offer different returns on parental investment depending on the state of the environment. Natural selection has therefore favoured maternal ability to manipulate offspring sex in response to environmental conditions in early life, as shown in variation in the sex ratio at birth. This argument can be extended to the whole period of parental investment until weaning. Male vulnerability in response to environmental stress in early life is predicted to have been favoured by natural selection. This vulnerability is most evident in the harsh conditions resulting from pre-term birth, but can also be seen in term infants, and manifests as greater morbidity and mortality persisting into early childhood. Malnutrition, interacting with infection after birth, is suggested as the fundamental trigger mechanism. The model suggests that whatever improvements are made in medical care, any environmental stress will always affect males more severely than females in early life. Copyright 2000 Academic Press.

Barium distributions in teeth reveal early life dietary transitions in primates

PubMed Central

Austin, Christine; Smith, Tanya M.; Bradman, Asa; Hinde, Katie; Joannes-Boyau, Renaud; Bishop, David; Hare, Dominic J.; Doble, Philip; Eskenazi, Brenda; Arora, Manish

2013-01-01

Early life dietary transitions reflect fundamental aspects of primate evolution and are important determinants of health in contemporary human populations1,2. Weaning is critical to developmental and reproductive rates; early weaning can have detrimental health effects but enables shorter inter-birth intervals, which influences population growth3. Uncovering early life dietary history in fossils is hampered by the absence of prospectively-validated biomarkers that are not modified during fossilisation4. Here we show that major dietary shifts in early life manifest as compositional variations in dental tissues. Teeth from human children and captive macaques, with prospectively-recorded diet histories, demonstrate that barium (Ba) distributions accurately reflect dietary transitions from the introduction of mother’s milk and through the weaning process. We also document transitions in a Middle Palaeolithic juvenile Neanderthal, which shows a pattern of exclusive breastfeeding for seven months, followed by seven months of supplementation. After this point, Ba levels in enamel returned to baseline prenatal levels, suggesting an abrupt cessation of breastfeeding at 1.2 years of age. Integration of Ba spatial distributions and histological mapping of tooth formation enables novel studies of the evolution of human life history, dietary ontogeny in wild primates, and human health investigations through accurate reconstructions of breastfeeding history. PMID:23698370

Barium distributions in teeth reveal early-life dietary transitions in primates.

PubMed

Austin, Christine; Smith, Tanya M; Bradman, Asa; Hinde, Katie; Joannes-Boyau, Renaud; Bishop, David; Hare, Dominic J; Doble, Philip; Eskenazi, Brenda; Arora, Manish

2013-06-13

Early-life dietary transitions reflect fundamental aspects of primate evolution and are important determinants of health in contemporary human populations. Weaning is critical to developmental and reproductive rates; early weaning can have detrimental health effects but enables shorter inter-birth intervals, which influences population growth. Uncovering early-life dietary history in fossils is hampered by the absence of prospectively validated biomarkers that are not modified during fossilization. Here we show that large dietary shifts in early life manifest as compositional variations in dental tissues. Teeth from human children and captive macaques, with prospectively recorded diet histories, demonstrate that barium (Ba) distributions accurately reflect dietary transitions from the introduction of mother's milk through the weaning process. We also document dietary transitions in a Middle Palaeolithic juvenile Neanderthal, which shows a pattern of exclusive breastfeeding for seven months, followed by seven months of supplementation. After this point, Ba levels in enamel returned to baseline prenatal levels, indicating an abrupt cessation of breastfeeding at 1.2 years of age. Integration of Ba spatial distributions and histological mapping of tooth formation enables novel studies of the evolution of human life history, dietary ontogeny in wild primates, and human health investigations through accurate reconstructions of breastfeeding history.

Water and Life on Mars

NASA Technical Reports Server (NTRS)

McKay, Christopher P.; DeVincenzi, Donald (Technical Monitor)

2000-01-01

Mars appears to be cold dry and dead world. However there is good evidence that early in its history it had liquid water, more active volcanism, and a thicker atmosphere. Mars had this earth-like environment over three and a half billion years ago, during the same time that life appeared on Earth. The main question in the exploration of Mars then is the search for a independent origin of life on that planet. Ecosystems in cold, dry locations on Earth - such as the Antarctic - provide examples of how life on Mars might have survived and where to look for fossils. Although the Viking results may indicate that Mars has no life today, there is direct geomorphological evidence that, in the past, Mars had large amounts of liquid water on its surface - possibly due to a thicker atmosphere. From a biological perspective the existence of liquid water, by itself motivates the question of the origin of life on Mars. One of the martian meteorites dates back to this early period and may contain evidence consistent with life. From studies of the Earth's earliest biosphere we know that by 3.5 Gyr. ago, life had originated on Earth and reached a fair degree of biological sophistication. Surface activity and erosion on Earth make it difficult to trace the history of life before the 3.5 Gyr timeframe. Ecosystems in cold, dry locations on Earth - such as the Antarctic - provide examples of how life on Mars might have survived and where to look for fossils.

Bayesian analysis of the astrobiological implications of life's early emergence on Earth.

PubMed

Spiegel, David S; Turner, Edwin L

2012-01-10

Life arose on Earth sometime in the first few hundred million years after the young planet had cooled to the point that it could support water-based organisms on its surface. The early emergence of life on Earth has been taken as evidence that the probability of abiogenesis is high, if starting from young Earth-like conditions. We revisit this argument quantitatively in a bayesian statistical framework. By constructing a simple model of the probability of abiogenesis, we calculate a bayesian estimate of its posterior probability, given the data that life emerged fairly early in Earth's history and that, billions of years later, curious creatures noted this fact and considered its implications. We find that, given only this very limited empirical information, the choice of bayesian prior for the abiogenesis probability parameter has a dominant influence on the computed posterior probability. Although terrestrial life's early emergence provides evidence that life might be abundant in the universe if early-Earth-like conditions are common, the evidence is inconclusive and indeed is consistent with an arbitrarily low intrinsic probability of abiogenesis for plausible uninformative priors. Finding a single case of life arising independently of our lineage (on Earth, elsewhere in the solar system, or on an extrasolar planet) would provide much stronger evidence that abiogenesis is not extremely rare in the universe.

Early-life family structure and microbially induced cancer risk.

PubMed

Blaser, Martin J; Nomura, Abraham; Lee, James; Stemmerman, Grant N; Perez-Perez, Guillermo I

2007-01-01

Cancer may follow exposure to an environmental agent after many decades. The bacterium Helicobacter pylori, known to be acquired early in life, increases risk for gastric adenocarcinoma, but other factors are also important. In this study, we considered whether early-life family structure affects the risk of later developing gastric cancer among H. pylori+ men. We examined a long-term cohort of Japanese-American men followed for 28 y, and performed a nested case-control study among those carrying H. pylori or the subset carrying the most virulent cagA+ H. pylori strains to address whether family structure predicted cancer development. We found that among the men who were H. pylori+ and/or cagA+ (it is possible to be cagA+ and H. pylori- if the H. pylori test is falsely negative), belonging to a large sibship or higher birth order was associated with a significantly increased risk of developing gastric adenocarcinoma late in life. For those with cagA+ strains, the risk of developing gastric cancer was more than twice as high (odds ratio 2.2; 95% confidence interval 1.2-4.0) among those in a sibship of seven or more individuals than in a sibship of between one and three persons. These results provide evidence that early-life social environment plays a significant role in risk of microbially induced malignancies expressing five to eight decades later, and these findings lead to new models to explain these interactions.

Early-Life Exposure to Non-Nutritive Sweeteners and the Developmental Origins of Childhood Obesity: Global Evidence from Human and Rodent Studies.

PubMed

Archibald, Alyssa J; Dolinsky, Vernon W; Azad, Meghan B

2018-02-10

Non-nutritive sweeteners (NNS) are increasingly consumed by children and pregnant women around the world, yet their long-term health impact is unclear. Here, we review an emerging body of evidence suggesting that early-life exposure to NNS may adversely affect body composition and cardio-metabolic health. Some observational studies suggest that children consuming NNS are at increased risk for obesity-related outcomes; however, others find no association or provide evidence of confounding. Fewer studies have examined prenatal NNS exposure, with mixed results from different analytical approaches. There is a paucity of RCTs evaluating NNS in children, yielding inconsistent results that can be difficult to interpret due to study design limitations (e.g., choice of comparator, multifaceted interventions). The majority of this research has been conducted in high-income countries. Some rodent studies demonstrate adverse metabolic effects from NNS, but most have used extreme doses that are not relevant to humans, and few have distinguished prenatal from postnatal exposure. Most studies focus on synthetic NNS in beverages, with few examining plant-derived NNS or NNS in foods. Overall, there is limited and inconsistent evidence regarding the impact of early-life NNS exposure on the developmental programming of obesity and cardio-metabolic health. Further research and mechanistic studies are needed to elucidate these effects and inform dietary recommendations for expectant mothers and children worldwide.

Impact of early life adversity on EMG stress reactivity of the trapezius muscle

PubMed Central

Luijcks, Rosan; Vossen, Catherine J.; Roggeveen, Suzanne; van Os, Jim; Hermens, Hermie J.; Lousberg, Richel

2016-01-01

Abstract Human and animal research indicates that exposure to early life adversity increases stress sensitivity later in life. While behavioral markers of adversity-induced stress sensitivity have been suggested, physiological markers remain to be elucidated. It is known that trapezius muscle activity increases during stressful situations. The present study examined to what degree early life adverse events experienced during early childhood (0–11 years) and adolescence (12–17 years) moderate experimentally induced electromyographic (EMG) stress activity of the trapezius muscles, in an experimental setting. In a general population sample (n = 115), an anticipatory stress effect was generated by presenting a single unpredictable and uncontrollable electrical painful stimulus at t = 3 minutes. Subjects were unaware of the precise moment of stimulus delivery and its intensity level. Linear and nonlinear time courses in EMG activity were modeled using multilevel analysis. The study protocol included 2 experimental sessions (t = 0 and t = 6 months) allowing for examination of reliability. Results show that EMG stress reactivity during the stress paradigm was consistently stronger in people with higher levels of early life adverse events; early childhood adversity had a stronger moderating effect than adolescent adversity. The impact of early life adversity on EMG stress reactivity may represent a reliable facet that can be used in both clinical and nonclinical studies. PMID:27684800

Biodemography of Exceptional Longevity: Early-life and Mid-life predictors of Human Longevity

PubMed Central

Gavrilov, Leonid A.; Gavrilova, Natalia S.

2011-01-01

Effects of early-life and middle-life conditions on exceptional longevity are explored in this study using two matched case-control studies. The first study compares 198 validated centenarians born in the United States in 1890-1893 to their shorter-lived siblings. Family histories of centenarians were reconstructed and exceptional longevity validated using early U.S. censuses, Social Security Administration Death Master File, state death indexes, online genealogies and other supplementary data resources. Siblings born to young mothers (<25 years) had significantly higher chances to live to 100 compared to siblings born to older mothers (odds ratio = 2.03, 95% CI = 1.33 - 3.11, P = 0.001) while paternal age and birth order were not associated with exceptional longevity. The second study explores whether people living to 100 and beyond are any different in physical characteristics at young age from their shorter-lived peers. A random representative sample of 240 men born in 1887 and survived to age 100 was selected from the US Social Security Administration database and linked to the US WWI civil draft registration cards collected in 1917 when these men were 30 years old. These validated centenarians were then compared to randomly selected controls matched by calendar year of birth, race and place of draft registration in 1917. It was found that ‘stout’ body build (being in the heaviest 15% of population) was negatively associated with survival to age 100 years. Farmer occupation and large number of children (4+) at age 30 increased the chances of exceptional longevity. Detailed description of dataset development, data cleaning procedure and validation of exceptional longevity is provided for both studies. These results demonstrate that matched case-control design is a useful approach in exploring effects of early-life conditions and middle-life characteristics on exceptional longevity. PMID:22582891

Diversity of the gut microbiota and eczema in early life.

PubMed

Forno, Erick; Onderdonk, Andrew B; McCracken, John; Litonjua, Augusto A; Laskey, Daniel; Delaney, Mary L; Dubois, Andrea M; Gold, Diane R; Ryan, Louise M; Weiss, Scott T; Celedón, Juan C

2008-09-22

A modest number of prospective studies of the composition of the intestinal microbiota and eczema in early life have yielded conflicting results. To examine the relationship between the bacterial diversity of the gut and the development of eczema in early life by methods other than stool culture. Fecal samples were collected from 21 infants at 1 and 4 months of life. Nine infants were diagnosed with eczema by the age of 6 months (cases) and 12 infants were not (controls). After conducting denaturating gradient gel electrophoresis (DGGE) of stool samples, we compared the microbial diversity of cases and controls using the number of electrophoretic bands and the Shannon index of diversity (H') as indicators. Control subjects had significantly greater fecal microbial diversity than children with eczema at ages 1 (mean H' for controls = 0.75 vs. 0.53 for cases, P = 0.01) and 4 months (mean H' for controls = 0.92 vs. 0.59 for cases, P = 0.02). The increase in diversity from 1 to 4 months of age was significant in controls (P = 0.04) but not in children who developed eczema by 6 months of age (P = 0.32). Our findings suggest that reduced microbial diversity is associated with the development of eczema in early life.

Effects of early life stress on amygdala and striatal development

PubMed Central

Fareri, Dominic S.; Tottenham, Nim

2016-01-01

Species-expected caregiving early in life is critical for the normative development and regulation of emotional behavior, the ability to effectively evaluate affective stimuli in the environment, and the ability to sustain social relationships. Severe psychosocial stressors early in life (early life stress; ELS) in the form of the absence of species expected caregiving (i.e., caregiver deprivation), can drastically impact one’s social and emotional success, leading to the onset of internalizing illness later in life. Development of the amygdala and striatum, two key regions supporting affective valuation and learning, is significantly affected by ELS, and their altered developmental trajectories have important implications for cognitive, behavioral and socioemotional development. However, an understanding of the impact of ELS on the development of functional interactions between these regions and subsequent behavioral effects is lacking. In this review, we highlight the roles of the amygdala and striatum in affective valuation and learning in maturity and across development. We discuss their function separately as well as their interaction. We highlight evidence across species characterizing how ELS induced changes in the development of the amygdala and striatum mediate subsequent behavioral changes associated with internalizing illness, positing a particular import of the effect of ELS on their interaction. PMID:27174149

Effects of early life stress on amygdala and striatal development.

PubMed

Fareri, Dominic S; Tottenham, Nim

2016-06-01

Species-expected caregiving early in life is critical for the normative development and regulation of emotional behavior, the ability to effectively evaluate affective stimuli in the environment, and the ability to sustain social relationships. Severe psychosocial stressors early in life (early life stress; ELS) in the form of the absence of species expected caregiving (i.e., caregiver deprivation), can drastically impact one's social and emotional success, leading to the onset of internalizing illness later in life. Development of the amygdala and striatum, two key regions supporting affective valuation and learning, is significantly affected by ELS, and their altered developmental trajectories have important implications for cognitive, behavioral and socioemotional development. However, an understanding of the impact of ELS on the development of functional interactions between these regions and subsequent behavioral effects is lacking. In this review, we highlight the roles of the amygdala and striatum in affective valuation and learning in maturity and across development. We discuss their function separately as well as their interaction. We highlight evidence across species characterizing how ELS induced changes in the development of the amygdala and striatum mediate subsequent behavioral changes associated with internalizing illness, positing a particular import of the effect of ELS on their interaction. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Growth in early life and the development of obesity by age 9 years: are there critical periods and a role for an early life stressor?

PubMed

Giles, L C; Whitrow, M J; Rumbold, A R; Davies, C E; de Stavola, B; Pitcher, J B; Davies, M J; Moore, V M

2013-04-01

Rapid growth, possibly occurring in critical periods in early life, may be important for the development of obesity. It is unknown whether this is influenced by postnatal exposures such as age-relevant sources of stress. Frequent house moves may be one such stressor. We aimed to examine if there is a period of growth in early life critical for the development of child obesity by age 9 years and assess the role of house moves in modifying any relationships between early life growth and obesity at age 9 years. Prospective Australian birth cohort study. In all, 392 children with serial body size measurements from birth to age 9 years. Standardized body mass index (z-BMI) was available for six time points (spanning birth to 3½ years), and the total number of house moves between birth and 3½ years. The outcomes considered were z-BMI and % body fat (%BF) at age 9 years. Linear regression models were used to estimate the effects of serial measurements of z-BMI and number of house moves on the outcomes. Life-course plots showed that z-BMI at 3½ years was a statistically significant predictor of z-BMI at 9 years (β=0.80; standard error (s.e.), 0.04), whereas z-BMI at 9 months (β=-1.13; s.e., 0.40) and 3½ years (β=4.82; s.e., 0.42) were significant predictors of %BF at age 9 years. There were statistically significant interactions between the number of house moves and change in z-BMI between 9 and 12 months, such that ≥ 3 house moves in early life amplified the detrimental effects of earlier rapid growth on both body size and composition at age 9 years. In the absence of evidence for a single critical period, efforts to prevent overweight and obesity are required throughout childhood. In addition, modifiable postnatal stressors may exacerbate effects of early growth on obesity in later childhood.

Early-Life Intelligence Predicts Midlife Biological Age.

PubMed

Schaefer, Jonathan D; Caspi, Avshalom; Belsky, Daniel W; Harrington, Honalee; Houts, Renate; Israel, Salomon; Levine, Morgan E; Sugden, Karen; Williams, Benjamin; Poulton, Richie; Moffitt, Terrie E

2016-11-01

Early-life intelligence has been shown to predict multiple causes of death in populations around the world. This finding suggests that intelligence might influence mortality through its effects on a general process of physiological deterioration (i.e., individual variation in "biological age"). We examined whether intelligence could predict measures of aging at midlife before the onset of most age-related disease. We tested whether intelligence assessed in early childhood, middle childhood, and midlife predicted midlife biological age in members of the Dunedin Study, a population-representative birth cohort. Lower intelligence predicted more advanced biological age at midlife as captured by perceived facial age, a 10-biomarker algorithm based on data from the National Health and Nutrition Examination Survey (NHANES), and Framingham heart age (r = 0.1-0.2). Correlations between intelligence and telomere length were less consistent. The associations between intelligence and biological age were not explained by differences in childhood health or parental socioeconomic status, and intelligence remained a significant predictor of biological age even when intelligence was assessed before Study members began their formal schooling. These results suggest that accelerated aging may serve as one of the factors linking low early-life intelligence to increased rates of morbidity and mortality. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Predicting Negative Life Outcomes from Early Aggressive-Disruptive Behavior Trajectories: Gender Differences in Maladaptation across Life Domains

ERIC Educational Resources Information Center

Bradshaw, Catherine P.; Schaeffer, Cindy M.; Petras, Hanno; Ialongo, Nicholas

2010-01-01

Transactional theories of development suggest that displaying high levels of antisocial behavior early in life and persistently over time causes disruption in multiple life domains, which in turn places individuals at risk for negative life outcomes. We used longitudinal data from 1,137 primarily African American urban youth (49.1% female) to…

The fuel cell model of abiogenesis: a new approach to origin-of-life simulations.

PubMed

Barge, Laura M; Kee, Terence P; Doloboff, Ivria J; Hampton, Joshua M P; Ismail, Mohammed; Pourkashanian, Mohamed; Zeytounian, John; Baum, Marc M; Moss, John A; Lin, Chung-Kuang; Kidd, Richard D; Kanik, Isik

2014-03-01

In this paper, we discuss how prebiotic geo-electrochemical systems can be modeled as a fuel cell and how laboratory simulations of the origin of life in general can benefit from this systems-led approach. As a specific example, the components of what we have termed the "prebiotic fuel cell" (PFC) that operates at a putative Hadean hydrothermal vent are detailed, and we used electrochemical analysis techniques and proton exchange membrane (PEM) fuel cell components to test the properties of this PFC and other geo-electrochemical systems, the results of which are reported here. The modular nature of fuel cells makes them ideal for creating geo-electrochemical reactors with which to simulate hydrothermal systems on wet rocky planets and characterize the energetic properties of the seafloor/hydrothermal interface. That electrochemical techniques should be applied to simulating the origin of life follows from the recognition of the fuel cell-like properties of prebiotic chemical systems and the earliest metabolisms. Conducting this type of laboratory simulation of the emergence of bioenergetics will not only be informative in the context of the origin of life on Earth but may help in understanding whether life might emerge in similar environments on other worlds.

Expression of glucocorticoid receptor and early growth response gene 1 during postnatal development of two inbred strains of mice exposed to early life stress.

PubMed

Navailles, Sylvia; Zimnisky, Ross; Schmauss, Claudia

2010-07-01

Early life stress can elicit profound changes in adult gene expression and behavior. One consequence of early life stress is a decreased expression of glucocorticoid receptors (GRs) in the frontal cortex and hippocampus. However, neither the time of onset nor the mechanism(s) leading to decreased GR expression during postnatal development are known. The present study used two inbred strains of mice that differ in their behavioral responsiveness to stress (Balb/c and C57Bl/6), exposed them to an established paradigm of early life stress (infant maternal separation), and measured their expression of frontal cortical and hippocampal GRs and the putative transcriptional activator of the GR gene, early growth response gene (egr)-1, at defined stages of postnatal development. In both strains, real-time RT-PCR experiments revealed that decreased expression of GR in adolescence and adulthood is, in fact, preceded by increased GR expression during early life stress exposure. Thus, the early life stress-induced disruption of the normal stress-hyporesponsive period during infancy is accompanied by increased GR expression. Moreover, chronic treatment with the antidepressant drug fluoxetine during adolescence or adulthood reversed the effect of early life stress on adult GR mRNA expression. In contrast to the strain-independent effect of early life stress on GR expression, however, changes in egr-1 expression occurred only in Balb/c mice, and unlike the biphasic developmental changes in GR mRNA expression, egr-1 mRNA was decreased throughout postnatal development. Moreover, there was no consistent overlap of anatomic regions affected by decreased GR and egr-1 protein expression. Thus, in Balb/c mice, changes in GR and egr-1 expression can independently contribute to the phenotypes resulting from early life stress exposure. These findings illustrate that the impact of early life stress on gene expression changes is modulated by the genetic background and that the persistent

The Origin of Dwarf Early-Type Galaxies

NASA Astrophysics Data System (ADS)

Toloba, Elisa

2012-10-01

Abridge. We have conducted a spectrophotometric study of dwarf early-type galaxies (dEs) in the Virgo cluster and in regions of lower density. We have found that these galaxies show many properties in common with late-type galaxies but not with more massive early-types (E/S0). The properties of the dEs in Virgo show gradients within the cluster. dEs in the outer parts of the Virgo cluster are kinematically supported by rotation, while those in the center are supported by the random motions of their stars (i.e. pressure supported). The rotationally supported dEs have disky isophotes and faint underlying spiral/irregular substructures, they also show younger ages than those pressure supported, which have boxy isophotes and are smooth and regular, without any substructure. We compare the position of these dEs with massive early-type galaxies in the Faber-Jackson and Fundamental Plane relations, and we find that, although there is no difference between the position of rotationally and pressure supported dEs, both deviate from the relations of massive early-type galaxies in the direction of dwarf spheroidal systems (dSphs). We have used their offset with respect to the Fundamental Plane of E/S0 galaxies to estimate their dark matter fraction. All the properties studied in this work agree with a ram pressure stripping scenario, where late-type galaxies infall into the cluster, their interaction with the intergalactic medium blows away their gas and, as a result, they are quenched in a small amount of time. However, those dEs in the center of the cluster seem to have been fully transformed leaving no trace of their possible spiral origin, thus, if that is the case, they must have experienced a more violent mechanism in combination with ram pressure stripping.

Ammonia and urea handling by early life stages of fishes.

PubMed

Zimmer, Alex M; Wright, Patricia A; Wood, Chris M

2017-11-01

Nitrogen metabolism in fishes has been a focus of comparative physiologists for nearly a century. In this Review, we focus specifically on early life stages of fishes, which have received considerable attention in more recent work. Nitrogen metabolism and excretion in early life differs fundamentally from that of juvenile and adult fishes because of (1) the presence of a chorion capsule in embryos that imposes a limitation on effective ammonia excretion, (2) an amino acid-based metabolism that generates a substantial ammonia load, and (3) the lack of a functional gill, which is the primary site of nitrogen excretion in juvenile and adult fishes. Recent findings have shed considerable light on the mechanisms by which these constraints are overcome in early life. Perhaps most importantly, the discovery of Rhesus (Rh) glycoproteins as ammonia transporters and their expression in ion-transporting cells on the skin of larval fishes has transformed our understanding of ammonia excretion by fishes in general. The emergence of larval zebrafish as a model species, together with genetic knockdown techniques, has similarly advanced our understanding of ammonia and urea metabolism and excretion by larval fishes. It has also now been demonstrated that ammonia excretion is one of the primary functions of the developing gill in rainbow trout larvae, leading to new hypotheses regarding the physiological demands driving gill development in larval fishes. Here, we highlight and discuss the dramatic changes in nitrogen handling that occur over early life development in fishes. © 2017. Published by The Company of Biologists Ltd.

Early Life Stress Differentially Modulates Distinct Forms of Brain Plasticity in Young and Adult Mice

PubMed Central

Reichardt, Wilfried; Clark, Kristin; Geiger, Julia; Gross, Claus M.; Heyer, Andrea; Neagu, Valentin; Bhatia, Harsharan; Atas, Hasan C.; Fiebich, Bernd L.; Bischofberger, Josef; Haas, Carola A.; Normann, Claus

2012-01-01

Background Early life trauma is an important risk factor for many psychiatric and somatic disorders in adulthood. As a growing body of evidence suggests that brain plasticity is disturbed in affective disorders, we examined the short-term and remote effects of early life stress on different forms of brain plasticity. Methodology/Principal Findings Mice were subjected to early deprivation by individually separating pups from their dam in the first two weeks after birth. Distinct forms of brain plasticity were assessed in the hippocampus by longitudinal MR volumetry, immunohistochemistry of neurogenesis, and whole-cell patch-clamp measurements of synaptic plasticity. Depression-related behavior was assessed by the forced swimming test in adult animals. Neuropeptides and their receptors were determined by real-time PCR and immunoassay. Early maternal deprivation caused a loss of hippocampal volume, which returned to normal in adulthood. Adult neurogenesis was unaffected by early life stress. Long-term synaptic potentiation, however, was normal immediately after the end of the stress protocol but was impaired in adult animals. In the forced swimming test, adult animals that had been subjected to early life stress showed increased immobility time. Levels of substance P were increased both in young and adult animals after early deprivation. Conclusion Hippocampal volume was affected by early life stress but recovered in adulthood which corresponded to normal adult neurogenesis. Synaptic plasticity, however, exhibited a delayed impairment. The modulation of synaptic plasticity by early life stress might contribute to affective dysfunction in adulthood. PMID:23071534

In the Beginning was a Mutualism - On the Origin of Translation

NASA Astrophysics Data System (ADS)

Vitas, Marko; Dobovišek, Andrej

2018-04-01

The origin of translation is critical for understanding the evolution of life, including the origins of life. The canonical genetic code is one of the most dominant aspects of life on this planet, while the origin of heredity is one of the key evolutionary transitions in living world. Why the translation apparatus evolved is one of the enduring mysteries of molecular biology. Assuming the hypothesis, that during the emergence of life evolution had to first involve autocatalytic systems which only subsequently acquired the capacity of genetic heredity, we propose and discuss possible mechanisms, basic aspects of the emergence and subsequent molecular evolution of translation and ribosomes, as well as enzymes as we know them today. It is possible, in this sense, to view the ribosome as a digital-to-analogue information converter. The proposed mechanism is based on the abilities and tendencies of short RNA and polypeptides to fold and to catalyse biochemical reactions. The proposed mechanism is in concordance with the hypothesis of a possible chemical co-evolution of RNA and proteins in the origin of the genetic code or even more generally at the early evolution of life on Earth. The possible abundance and availability of monomers at prebiotic conditions are considered in the mechanism. The hypothesis that early polypeptides were folding on the RNA scaffold is also considered and mutualism in molecular evolutionary development of RNA and peptides is favoured.

The Role of Early-Life Educational Quality and Literacy in Explaining Racial Disparities in Cognition in Late Life

PubMed Central

Gross, Alden L.; Shih, Regina A.; Sachs, Bonnie C.; Glymour, M. Maria; Bangen, Katherine J.; Benitez, Andreana; Skinner, Jeannine; Schneider, Brooke C.; Manly, Jennifer J.

2015-01-01

Objectives. Racial disparities in late-life cognition persist even after accounting for educational attainment. We examined whether early-life educational quality and literacy in later life help explain these disparities. Method. We used longitudinal data from the Washington Heights-Inwood Columbia Aging Project (WHICAP). Educational quality (percent white students; urban/rural school; combined grades in classroom) was operationalized using canonical correlation analysis. Late-life literacy (reading comprehension and ability, writing) was operationalized using confirmatory factor analysis. We examined whether these factors attenuated race-related differences in late-life cognition. Results. The sample consisted of 1,679U.S.-born, non-Hispanic, community-living adults aged 65–102 (71% black, 29% white; 70% women). Accounting for educational quality and literacy reduced disparities by 29% for general cognitive functioning, 26% for memory, and 32% for executive functioning but did not predict differences in rate of cognitive change. Discussion. Early-life educational quality and literacy in late life explain a substantial portion of race-related disparities in late-life cognitive function. PMID:24584038

A 'Warm Formamide' Scenario for the Origins of Life Might Not Be so Hot Comment on 'Formamide and the Origin of Life' by E. Di Mauro Et Al.

NASA Technical Reports Server (NTRS)

Burton, Aaron S.

2012-01-01

In this review, Saladino et al. present an intriguing hypothesis surrounding the role of formamide in the originsof life on Earth, backed by experimental results supporting each step from formamide to RNA polymers [1]. The overall premise is that, from formamide and inorganic phosphate, RNA molecules over 100 nucleotides in length canbe produced. In addition, many carboxylic acids likely relevant to prebiotic metabolism are formed along the way. Thus, from a rather simple organic molecule that has been observed in outer space (formamide), you can generatemany of the compounds necessary for the origins of life. However, because high temperatures (160 C) are requiredfor the formamide reactions, it remains unclear where the warm formamide scenario could have occurred.Low-temperature, aqueous hydrogen counter to the observation that all protein-catalyzed ligation and polymerization reactions of RNA and DNA requireactivated substrates. Detailed mechanistic studies of the reported reactions are warranted and could provide important insights for understanding the chemistry behind the origins of life.Because the authors have produced many of the experimental results supporting their hypothesis, they coulddemonstrate the validity of their hypothesis by converting formamide into 100 nucleotide RNA oligomers, usingthe products of one reaction as the reactants for the next reaction, under specific conditions plausible on the pre-bioticEarth. Such a demonstration would represent a milestone for our understanding of the origins of life.cyanide-based prebiotic chemistry that we know actually happened has beenshown to produce many of the molecules invoked in the formamide hypothesis: amino acids, carboxylic acids, sugaracids, and nucleobases have all been found in meteorites recovered on Earth [e.g. [24

Depression is an independent determinant of life satisfaction early after stroke.

PubMed

Oosterveer, Daniëlla M; Mishre, Radha Rambaran; van Oort, Andrea; Bodde, Karin; Aerden, Leo A M

2017-03-06

Life satisfaction is reduced in stroke patients. However, as a rule, rehabilitation goals are not aimed at life satisfaction, but at activities and participation. In order to optimize life satisfaction in stroke patients, rehabilitation should take into account the determinants of life satisfaction. The aim of this study was therefore to determine what factors are independent determinants of life satisfaction in a large group of patients early after stroke. Stroke-surviving patients were examined by a specialized nurse 6 weeks after discharge from hospital or rehabilitation setting. A standardized history and several screening lists, including the Lisat-9, were completed. Step-wise regression was used to identify independent determinants of life satisfaction. A total of 284 stroke-surviving patients were included in the study. Of these, 117 answered all of the Lisat-9 questions. Most patients (66.5%) rated their life as a whole as "satisfying" or "very satisfying". More depressive symptoms were independently associated with lower life satisfaction (p < 0.001). Most stroke-surviving patients are satisfied with their life early after a stroke. The score on the Hospital Anxiety and Depression Scale depression items is independently associated with life satisfaction. Physicians should therefore pay close attention to the mood of these patients.

Key science questions from the second conference on early Mars: geologic, hydrologic, and climatic evolution and the implications for life.

PubMed

Beaty, David W; Clifford, Stephen M; Borg, Lars E; Catling, David C; Craddock, Robert A; Des Marais, David J; Farmer, Jack D; Frey, Herbert V; Haberle, Robert M; McKay, Christopher P; Newsom, Horton E; Parker, Timothy J; Segura, Teresa; Tanaka, Kenneth L

2005-12-01

In October 2004, more than 130 terrestrial and planetary scientists met in Jackson Hole, WY, to discuss early Mars. The first billion years of martian geologic history is of particular interest because it is a period during which the planet was most active, after which a less dynamic period ensued that extends to the present day. The early activity left a fascinating geological record, which we are only beginning to unravel through direct observation and modeling. In considering this time period, questions outnumber answers, and one of the purposes of the meeting was to gather some of the best experts in the field to consider the current state of knowledge, ascertain which questions remain to be addressed, and identify the most promising approaches to addressing those questions. The purpose of this report is to document that discussion. Throughout the planet's first billion years, planetary-scale processes-including differentiation, hydrodynamic escape, volcanism, large impacts, erosion, and sedimentation-rapidly modified the atmosphere and crust. How did these processes operate, and what were their rates and interdependencies? The early environment was also characterized by both abundant liquid water and plentiful sources of energy, two of the most important conditions considered necessary for the origin of life. Where and when did the most habitable environments occur? Did life actually occupy them, and if so, has life persisted on Mars to the present? Our understanding of early Mars is critical to understanding how the planet we see today came to be.

Bioaccumulation of lipophilic substances in fish early life stages

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petersen, G.I.; Kristensen, P.

1998-07-01

Accumulation of {sup 14}C-labeled polycyclic aromatic hydrocarbons, naphthalene, phenanthrene, pyrene, and benzo(a)pyrene and polychlorinated biphenyl (PCB) congeners PCB 31 and PCB 105 with a log octanol/water partition coefficient (K{sub ow}) range from 3.37 to 6.5 was investigated in eggs and larvae of zebra fish (Brachydanio rerio), and in larvae of cod (Gadus morhua), herring (Clupea harengus), and turbot (Scophthalmus maximus). Significant differences in the uptake and elimination rate constants between eggs and larvae of zebra fish were seen. The low rate of uptake and the lower elimination rate of eggs did, however, lead to bioconcentration factors (BCFs) comparable to thosemore » for larvae. As biotransformation of xenobiotics in embryonic and larval stages was indicated to be insignificant compared to juvenile/adult stages, body burdens of readily biotransformed chemicals may be higher in fish early life stages. Because weight and lipid content did not differ much between the investigated species, the main reason for the variability in BCFs between marine species and freshwater species was considered to be caused by differences in exposure temperatures that affect the degree of biotransformation. Due to the smaller size of larvae and thus an increased total surface of the membranes per unit fish weight, steady-state conditions were reached at a faster r/ate in early life stages than in juvenile/adult life stages. The lipid-normalized bioconcentration factors (BCF{sub L}) were linearly related to K{sub ow} but BCF{sub L} was, in general, higher than K{sub ow}, indicating that octanol is not a suitable surrogate for fish lipids. Differences in bioconcentration kinetics between larvae and juvenile/adult life stages are considered to be the main reason for the higher sensitivity, with respect to external effect concentrations, generally obtained for early life stages of fish.« less

Early life exposures and the risk of adult glioma.

PubMed

Anic, Gabriella M; Madden, Melissa H; Sincich, Kelly; Thompson, Reid C; Nabors, L Burton; Olson, Jeffrey J; LaRocca, Renato V; Browning, James E; Pan, Edward; Egan, Kathleen M

2013-09-01

Exposure to common infections in early life may stimulate immune development and reduce the risk for developing cancer. Birth order and family size are proxies for the timing of exposure to childhood infections with several studies showing a reduced risk of glioma associated with a higher order of birth (and presumed younger age at infection). The aim of this study was to examine whether birth order, family size, and other early life exposures are associated with the risk of glioma in adults using data collected in a large clinic-based US case-control study including 889 glioma cases and 903 community controls. A structured interviewer-administered questionnaire was used to collect information on family structure, childhood exposures and other potential risk factors. Logistic regression was used to calculate odds ratios (OR) and corresponding 95% confidence intervals (CI) for the association between early life factors and glioma risk. Persons having any siblings were at significantly lower risk for glioma when compared to those reporting no siblings (OR=0.64; 95% CI 0.44-0.93; p=0.020). Compared to first-borns, individuals with older siblings had a significantly lower risk (OR=0.75; 95% CI 0.61-0.91; p=0.004). Birth weight, having been breast fed in infancy, and season of birth were not associated with glioma risk. The current findings lend further support to a growing body of evidence that early exposure to childhood infections reduces the risk of glioma onset in children and adults.

Early-life exposure to substance abuse and risk of type 2 diabetes in adulthood.

PubMed

Vaiserman, A M

2015-08-01

Type 2 diabetes (T2D) is a chronic non-communicable disease that is driven by insulin resistance as a result of increasing obesity and decreasing activity levels that occur with increasing age. This disease generally develops after the age of 40, but it is now increasingly diagnosed in children and young adults. Increasing evidence, however, suggests that T2D can originate during early development. It has been repeatedly found that malnutrition during the gestational period can result in intrauterine growth restriction and low birth weight, which in combination with postnatal catch-up growth may subsequently lead to the development of T2D. There is ample evidence that T2D may also be programmed by maternal substance abuse (the harmful use of psychoactive substances such as illicit drugs or alcohol) during pregnancy and/or lactation. The research activity in this field is currently mainly focused on the childhood health problems following prenatal exposures to substance abuse. The delayed programming effects on adult-onset disorders, including metabolic syndrome and T2D, however, have been reported only rarely. This review provides animal and human evidence that early-life exposure to substance abuse, including alcohol, nicotine, and cocaine, may program not only childhood health outcomes but also life-long metabolic health status, including risk of T2D and related conditions.

The Suckling Rat as a Model for Immunonutrition Studies in Early Life

PubMed Central

Pérez-Cano, Francisco J.; Franch, Àngels; Castellote, Cristina; Castell, Margarida

2012-01-01

Diet plays a crucial role in maintaining optimal immune function. Research demonstrates the immunomodulatory properties and mechanisms of particular nutrients; however, these aspects are studied less in early life, when diet may exert an important role in the immune development of the neonate. Besides the limited data from epidemiological and human interventional trials in early life, animal models hold the key to increase the current knowledge about this interaction in this particular period. This paper reports the potential of the suckling rat as a model for immunonutrition studies in early life. In particular, it describes the main changes in the systemic and mucosal immune system development during rat suckling and allows some of these elements to be established as target biomarkers for studying the influence of particular nutrients. Different approaches to evaluate these immune effects, including the manipulation of the maternal diet during gestation and/or lactation or feeding the nutrient directly to the pups, are also described in detail. In summary, this paper provides investigators with useful tools for better designing experimental approaches focused on nutrition in early life for programming and immune development by using the suckling rat as a model. PMID:22899949

Disproportionate Exposure to Early-Life Adversity and Sexual Orientation Disparities in Psychiatric Morbidity

ERIC Educational Resources Information Center

McLaughlin, Katie A.; Hatzenbuehler, Mark L.; Xuan, Ziming; Conron, Kerith J.

2012-01-01

Objectives: Lesbian, gay, and bisexual (LGB) populations exhibit elevated rates of psychiatric disorders compared to heterosexuals, and these disparities emerge early in the life course. We examined the role of exposure to early-life victimization and adversity--including physical and sexual abuse, homelessness, and intimate partner violence--in…

Early-life predictors of leisure-time physical inactivity in midadulthood: findings from a prospective British birth cohort.

PubMed

Pinto Pereira, Snehal M; Li, Leah; Power, Chris

2014-12-01

Much adult physical inactivity research ignores early-life factors from which later influences may originate. In the 1958 British birth cohort (followed from 1958 to 2008), leisure-time inactivity, defined as activity frequency of less than once a week, was assessed at ages 33, 42, and 50 years (n = 12,776). Early-life factors (at ages 0-16 years) were categorized into 3 domains (i.e., physical, social, and behavioral). We assessed associations of adult inactivity 1) with factors within domains, 2) with the 3 domains combined, and 3) allowing for adult factors. At each age, approximately 32% of subjects were inactive. When domains were combined, factors associated with inactivity (e.g., at age 50 years) were prepubertal stature (5% lower odds per 1-standard deviation higher height), hand control/coordination problems (14% higher odds per 1-point increase on a 4-point scale), cognition (10% lower odds per 1-standard deviation greater ability), parental divorce (21% higher odds), institutional care (29% higher odds), parental social class at child's birth (9% higher odds per 1-point reduction on a 4-point scale), minimal parental education (13% higher odds), household amenities (2% higher odds per increase (representing poorer amenities) on a 19-point scale), inactivity (8% higher odds per 1-point reduction in activity on a 4-point scale), low sports aptitude (13% higher odds), and externalizing behaviors (i.e., conduct problems) (5% higher odds per 1-standard deviation higher score). Adjustment for adult covariates weakened associations slightly. Factors from early life were associated with adult leisure-time inactivity, allowing for early identification of groups vulnerable to inactivity. © The Author 2014. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Early life socioeconomic status, chronic physiological stress and hippocampal N-acetyl aspartate concentrations.

PubMed

McLean, John; Krishnadas, Rajeev; Batty, G David; Burns, Harry; Deans, Kevin A; Ford, Ian; McConnachie, Alex; McGinty, Agnes; McLean, Jennifer S; Millar, Keith; Sattar, Naveed; Shiels, Paul G; Tannahill, Carol; Velupillai, Yoga N; Packard, Chris J; Condon, Barrie R; Hadley, Donald M; Cavanagh, Jonathan

2012-12-01

Early life socioeconomic deprivation has been associated with cognitive and behavioural changes that persist through towards adulthood. In this study, we investigated whether early life socioeconomic status is associated with changes in the hippocampus N-acetyl aspartate (NAA), using the non-invasive technique of magnetic resonance spectroscopy (MRS). We performed proton magnetic resonance spectroscopy ((1)H-MRS) of the hippocampus at 3T in 30 adult males, selected from the PSOBID cohort. We conducted multiple regression analysis to examine the relationship between early socioeconomic status (SES) and concentration of N-acetyl-aspartate in the hippocampus. We also examined whether the relationship between these variables was mediated by markers of chronic physiological stress. Greater socioeconomic deprivation was associated with lower hippocampal NAA concentrations bilaterally. The relationship between early life SES and hippocampal NAA concentrations was mediated by allostatic load index - a marker of chronic physiological stress. Greater early life socioeconomic deprivation was associated with lower concentrations of NAA reflecting lesser neuronal integrity. This relationship was mediated by greater physiological stress. Further work, to better understand the biological processes underlying the effects of poverty, physiological stress on hippocampal metabolites is necessary. Copyright © 2012 Elsevier B.V. All rights reserved.

Early solar system. Stellar origin of the ¹⁸²Hf cosmochronometer and the presolar history of solar system matter.

PubMed

Lugaro, Maria; Heger, Alexander; Osrin, Dean; Goriely, Stephane; Zuber, Kai; Karakas, Amanda I; Gibson, Brad K; Doherty, Carolyn L; Lattanzio, John C; Ott, Ulrich

2014-08-08

Among the short-lived radioactive nuclei inferred to be present in the early solar system via meteoritic analyses, there are several heavier than iron whose stellar origin has been poorly understood. In particular, the abundances inferred for (182)Hf (half-life = 8.9 million years) and (129)I (half-life = 15.7 million years) are in disagreement with each other if both nuclei are produced by the rapid neutron-capture process. Here, we demonstrate that contrary to previous assumption, the slow neutron-capture process in asymptotic giant branch stars produces (182)Hf. This has allowed us to date the last rapid and slow neutron-capture events that contaminated the solar system material at ~100 million years and ~30 million years, respectively, before the formation of the Sun. Copyright © 2014, American Association for the Advancement of Science.

Work-Life Balance, Burnout, and Satisfaction of Early Career Pediatricians.

PubMed

Starmer, Amy J; Frintner, Mary Pat; Freed, Gary L

2016-04-01

Data describing factors associated with work-life balance, burnout, and career and life satisfaction for early career pediatricians are limited. We sought to identify personal and work factors related to these outcomes. We analyzed 2013 survey data of pediatricians who graduated residency between 2002 and 2004. Dependent variables included: (1) balance between personal and professional commitments, (2) current burnout in work, (3) career satisfaction, and (4) life satisfaction. Multivariable logistic regression examined associations of personal and work characteristics with each of the 4 dependent variables. A total of 93% of participants completed the survey (n = 840). A majority reported career (83%) and life (71%) satisfaction. Fewer reported current appropriate work-life balance (43%) or burnout (30%). In multivariable modeling, excellent/very good health, having support from physician colleagues, and adequate resources for patient care were all found to be associated with a lower prevalence of burnout and a higher likelihood of work-life balance and career and life satisfaction. Having children, race, and clinical specialty were not found to be significantly associated with any of the 4 outcome measures. Female gender was associated with a lower likelihood of balance and career satisfaction but did not have an association with burnout or life satisfaction. Burnout and struggles with work-life balance are common; dissatisfaction with life and career are a concern for some early career pediatricians. Efforts to minimize these outcomes should focus on encouragement of modifiable factors, including health supervision, peer support, and ensuring sufficient patient care resources. Copyright © 2016 by the American Academy of Pediatrics.

Early-Life Nutritional Programming of Type 2 Diabetes: Experimental and Quasi-Experimental Evidence.

PubMed

Vaiserman, Alexander M

2017-03-05

Consistent evidence from both experimental and human studies suggest that inadequate nutrition in early life can contribute to risk of developing metabolic disorders including type 2 diabetes (T2D) in adult life. In human populations, most findings supporting a causative relationship between early-life malnutrition and subsequent risk of T2D were obtained from quasi-experimental studies ('natural experiments'). Prenatal and/or early postnatal exposures to famine were demonstrated to be associated with higher risk of T2D in many cohorts around the world. Recent studies have highlighted the importance of epigenetic regulation of gene expression as a possible major contributor to the link between the early-life famine exposure and T2D in adulthood. Findings from these studies suggest that prenatal exposure to the famine may result in induction of persistent epigenetic changes that have adaptive significance in postnatal development but can predispose to metabolic disorders including T2D at the late stages of life. In this review, quasi-experimental data on the developmental programming of T2D are summarized and recent research findings on changes in DNA methylation that mediate these effects are discussed.

Early-Life Nutritional Programming of Type 2 Diabetes: Experimental and Quasi-Experimental Evidence

PubMed Central

Vaiserman, Alexander M.

2017-01-01

Consistent evidence from both experimental and human studies suggest that inadequate nutrition in early life can contribute to risk of developing metabolic disorders including type 2 diabetes (T2D) in adult life. In human populations, most findings supporting a causative relationship between early-life malnutrition and subsequent risk of T2D were obtained from quasi-experimental studies (‘natural experiments’). Prenatal and/or early postnatal exposures to famine were demonstrated to be associated with higher risk of T2D in many cohorts around the world. Recent studies have highlighted the importance of epigenetic regulation of gene expression as a possible major contributor to the link between the early-life famine exposure and T2D in adulthood. Findings from these studies suggest that prenatal exposure to the famine may result in induction of persistent epigenetic changes that have adaptive significance in postnatal development but can predispose to metabolic disorders including T2D at the late stages of life. In this review, quasi-experimental data on the developmental programming of T2D are summarized and recent research findings on changes in DNA methylation that mediate these effects are discussed. PMID:28273874

Arsenic and Immune Response to Infection During Pregnancy and Early Life.

PubMed

Attreed, Sarah E; Navas-Acien, Ana; Heaney, Christopher D

2017-06-01

Arsenic, a known carcinogen and developmental toxicant, is a major threat to global health. While the contribution of arsenic exposure to chronic diseases and adverse pregnancy and birth outcomes is recognized, its ability to impair critical functions of humoral and cell-mediated immunity-including the specific mechanisms in humans-is not well understood. Arsenic has been shown to increase risk of infectious diseases that have significant health implications during pregnancy and early life. Here, we review the latest research on the mechanisms of arsenic-related immune response alterations that could underlie arsenic-associated increased risk of infection during the vulnerable periods of pregnancy and early life. The latest evidence points to alteration of antibody production and transplacental transfer as well as failure of T helper cells to produce IL-2 and proliferate. Critical areas for future research include the effects of arsenic exposure during pregnancy and early life on immune responses to natural infection and the immunogenicity and efficacy of vaccines.

The effect of early-life education on later-life mortality.

PubMed

Black, Dan A; Hsu, Yu-Chieh; Taylor, Lowell J

2015-12-01

Many studies link cross-state variation in compulsory schooling laws to early-life educational attainment, thereby providing a plausible way to investigate the causal impact of education on various lifetime outcomes. We use this strategy to estimate the effect of education on older-age mortality of individuals born in the early twentieth century U.S. Our key innovation is to combine U.S. Census data and the complete Vital Statistics records to form precise mortality estimates by sex, birth cohort, and birth state. In turn we find that virtually all of the variation in these mortality rates is captured by cohort effects and state effects alone, making it impossible to reliably tease out any additional impact due to changing educational attainment induced by state-level changes in compulsory schooling. Copyright © 2015. Published by Elsevier B.V.

Solar UV Radiation and the Origin of Life on Earth

NASA Technical Reports Server (NTRS)

Heap, S. R.; Gaidos, E.; Hubeny, I.; Lanz, T. M.; Fisher, Richard R. (Technical Monitor)

2001-01-01

We have embarked on a program aimed at understanding the atmosphere of the early Earth, because of its importance as a greenhouse, radiation shield, and energy source for life. Here, we give a progress report on the first phase of this program: to establish the UV radiation from the early Sun. We are presently obtaining ultraviolet spectra (STIS, FUSE, EUVE) of carefully selected nearby, young solar-type stars, which act as surrogates for the early Sun. We are currently making detailed non-LTE analyses of the spectra and constructing models of their photospheres + chromospheres. once validated, these models will allow us to extrapolate our theoretical spectra to unobserved spectral regions, and to proceed to the next step: to develop photochemical models of the pre-biotic and Archean atmosphere of the Earth.

From chemical metabolism to life: the origin of the genetic coding process

PubMed Central

2017-01-01

Looking for origins is so much rooted in ideology that most studies reflect opinions that fail to explore the first realistic scenarios. To be sure, trying to understand the origins of life should be based on what we know of current chemistry in the solar system and beyond. There, amino acids and very small compounds such as carbon dioxide, dihydrogen or dinitrogen and their immediate derivatives are ubiquitous. Surface-based chemical metabolism using these basic chemicals is the most likely beginning in which amino acids, coenzymes and phosphate-based small carbon molecules were built up. Nucleotides, and of course RNAs, must have come to being much later. As a consequence, the key question to account for life is to understand how chemical metabolism that began with amino acids progressively shaped into a coding process involving RNAs. Here I explore the role of building up complementarity rules as the first information-based process that allowed for the genetic code to emerge, after RNAs were substituted to surfaces to carry over the basic metabolic pathways that drive the pursuit of life. PMID:28684991

Co-evolution of atmospheres, life, and climate.

PubMed

Grenfell, J Lee; Rauer, Heike; Selsis, Franck; Kaltenegger, Lisa; Beichman, Charles; Danchi, William; Eiroa, Carlos; Fridlund, Malcolm; Henning, Thomas; Herbst, Tom; Lammer, Helmut; Léger, Alain; Liseau, René; Lunine, Jonathan; Paresce, Francesco; Penny, Alan; Quirrenbach, Andreas; Röttgering, Huub; Schneider, Jean; Stam, Daphne; Tinetti, Giovanna; White, Glenn J

2010-01-01

After Earth's origin, our host star, the Sun, was shining 20-25% less brightly than today. Without greenhouse-like conditions to warm the atmosphere, our early planet would have been an ice ball, and life may never have evolved. But life did evolve, which indicates that greenhouse gases must have been present on early Earth to warm the planet. Evidence from the geological record indicates an abundance of the greenhouse gas CO(2). CH(4) was probably present as well; and, in this regard, methanogenic bacteria, which belong to a diverse group of anaerobic prokaryotes that ferment CO(2) plus H(2) to CH(4), may have contributed to modification of the early atmosphere. Molecular oxygen was not present, as is indicated by the study of rocks from that era, which contain iron carbonate rather than iron oxide. Multicellular organisms originated as cells within colonies that became increasingly specialized. The development of photosynthesis allowed the Sun's energy to be harvested directly by life-forms. The resultant oxygen accumulated in the atmosphere and formed the ozone layer in the upper atmosphere. Aided by the absorption of harmful UV radiation in the ozone layer, life colonized Earth's surface. Our own planet is a very good example of how life-forms modified the atmosphere over the planets' lifetime. We show that these facts have to be taken into account when we discover and characterize atmospheres of Earth-like exoplanets. If life has originated and evolved on a planet, then it should be expected that a strong co-evolution occurred between life and the atmosphere, the result of which is the planet's climate.

Air pollution in early life and adult mortality from chronic rheumatic heart disease.

PubMed

Phillips, David I W; Osmond, Clive; Williams, Martin L; Jones, Alexander

2017-08-01

Chronic rheumatic heart disease (RHD) remains a globally important cause of heart disease. The reasons for the continuing high prevalence of this disease are obscure, but it may have its origins in the poor social and economic conditions with which the disease has been consistently and strongly linked. Mortality studies from the UK have suggested the importance of adverse environmental factors in early life; these studies demonstrated specific geographical associations between high rates of chest infection during infancy and subsequent RHD. They raised the possibility that early air pollution, which is known to be strongly linked with chest infection during infancy, may predispose to RHD. We related estimates of air pollution and social conditions developed by Daly in 1951-52 for 78 urban areas in England and Wales to their subsequent RHD mortality rates at ages 35-74 in men and women during 1993-2012. There were strong relationships between domestic air pollution and RHD [relative risk per standard deviation (SD) increase in pollution 1.168, 95% confidence interval (CI): 1.128 to 1.210, P < 0.001). Inclusion of published data on social class, education, crowding and population density in multiple regression analyses showed that the air pollution association was independent of these; only overcrowding was separately linked with RHD. We present the first evidence of an association between air pollution in early life and RHD. Although there are several limitations to this study, the strength and consistency of the results, together with their biological plausibility, suggest a causal link. This deserves attention because it may have important consequences for the control of RHD in resource-poor countries where widespread use of biomass fuels and domestic pollution remain a problem. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association

A "Warm Formamide" Scenario for the Origins of Life Might not be so Hot: Comment on "Formamide and the Origin of Life"

NASA Technical Reports Server (NTRS)

Burton, Aaron S.

2012-01-01

In this review, Saladino et al. present an intriguing hypothesis surrounding the role of formamide in the origins of life on Earth, backed by experimental results supporting each step from formamide to RNA polymers. The overall premise is that, from formamide and inorganic phosphate, RNA molecules over 100 nucleotides in length can be produced. In addition, many carboxylic acids likely relevant to prebiotic metabolism, are formed along the way. Thus, from a rather simple organic molecule that has been observed in outer space (formamide), you can generate many of the compounds necessary for the origins of life. However, because high temperatures (160 C) are required for the formamide reactions, it remains unclear where the "warm formamide" scenario could have occurred. Low-temperature, aqueous hydrogen cyanide-based prebiotic chemistry that we know actually happened has been shown to produce many of the molecules invoked in the formamide hypothesis: amino acids, carboxylic acids, sugar acids, and nucleobases have all been found in meteorites recovered on Earth, providing a plausible route for their synthesis and delivery. In contrast, a large portion of the formamide hypothesis is based on relatively hightemperature reactions, A plausible milieu for high-temperature reactions with concentrated formamide is yet to be described, and is critical for this hypothesis to be validated. Hydrothermal vents are attractive heat sources, and the higher boiling point of formamide has been invoked as a mechanism to concentrate it from an aqueous solution, Unless the water can actually evaporate, however, there would be no net enrichment. For example, in the context of a deep-sea vent, any water "removed" by heating would be quickly replaced. Some of the individual reactions underpinning the present hypothesis have been met with skepticism because they go against conventional wisdom, To name a few of the surprising results: the observation that nucleosides can be converted to

Early life factors and dental caries in 5-year-old children in China.

PubMed

Sun, Xiangyu; Bernabé, Eduardo; Liu, Xuenan; Gallagher, Jennifer E; Zheng, Shuguo

2017-09-01

This study aimed to explore the association between early life factors and dental caries among 5-year-old Chinese children. Data from 9722 preschool children who participated in the third National Oral Health Survey of China were analysed. Information on early life (birth weight, breastfeeding and age when toothbrushing started), child (sex, ethnicity, birth order and dental behaviours) and family factors (parental education, household income, place of residence, number of children in the family, respondent's age and relation to the child) were obtained from parental questionnaires. Children were also clinically examined to assess dental caries experience using the decayed, missing and filled teeth (dmft) index. The association of early life factors with dmft was evaluated in negative binomial regression models. We found that birth weight was not associated with dental caries experience; children who were exclusively and predominantly formula-fed had lower dmft values than those exclusively breastfed; and children who started brushing later in life had higher dmft values than those who were brushing within the first year. Only one in seven of all children received regular toothbrushing twice per day, and only 34.7% had commenced toothbrushing by the age of 3 years. This study shows certain early life factors play a role in dental caries among Chinese preschool children and provides important insights to shape public health initiatives on the importance of introducing early toothbrushing. The early environment, especially the age when parents introduce toothbrushing to their children, can be an important factor to prevent childhood dental caries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Simulating the origins of life: The dual role of RNA replicases as an obstacle to evolution.

PubMed

Szostak, Natalia; Synak, Jaroslaw; Borowski, Marcin; Wasik, Szymon; Blazewicz, Jacek

2017-01-01

Despite years of study, it is still not clear how life emerged from inanimate matter and evolved into the complex forms that we observe today. One of the most recognized hypotheses for the origins of life, the RNA World hypothesis, assumes that life was sparked by prebiotic replicating RNA chains. In this paper, we address the problems caused by the interplay between hypothetical prebiotic RNA replicases and RNA parasitic species. We consider the coexistence of parasite RNAs and RNA replicases as well as the impact of parasites on the further evolution of replicases. For these purposes, we used multi-agent modeling techniques that allow for realistic assumptions regarding the movement and spatial interactions of modeled species. The general model used in this study is based on work by Takeuchi and Hogeweg. Our results confirm that the coexistence of parasite RNAs and replicases is possible in a spatially extended system, even if we take into consideration more realistic assumptions than Takeuchi and Hogeweg. However, we also showed that the presence of trade-off that takes into the account an RNA folding process could still pose a serious obstacle to the evolution of replication. We conclude that this might be a cause for one of the greatest transitions in life that took place early in evolution-the separation of the function between DNA templates and protein enzymes, with a central role for RNA species.

The role of early-life educational quality and literacy in explaining racial disparities in cognition in late life.

PubMed

Sisco, Shannon; Gross, Alden L; Shih, Regina A; Sachs, Bonnie C; Glymour, M Maria; Bangen, Katherine J; Benitez, Andreana; Skinner, Jeannine; Schneider, Brooke C; Manly, Jennifer J

2015-07-01

Racial disparities in late-life cognition persist even after accounting for educational attainment. We examined whether early-life educational quality and literacy in later life help explain these disparities. We used longitudinal data from the Washington Heights-Inwood Columbia Aging Project (WHICAP). Educational quality (percent white students; urban/rural school; combined grades in classroom) was operationalized using canonical correlation analysis. Late-life literacy (reading comprehension and ability, writing) was operationalized using confirmatory factor analysis. We examined whether these factors attenuated race-related differences in late-life cognition. The sample consisted of 1,679 U.S.-born, non-Hispanic, community-living adults aged 65-102 (71% black, 29% white; 70% women). Accounting for educational quality and literacy reduced disparities by 29% for general cognitive functioning, 26% for memory, and 32% for executive functioning but did not predict differences in rate of cognitive change. Early-life educational quality and literacy in late life explain a substantial portion of race-related disparities in late-life cognitive function. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Fourth Symposium on Chemical Evolution and the Origin and Evolution of Life

NASA Technical Reports Server (NTRS)

Wharton, Robert A., Jr. (Editor); Andersen, Dale T. (Editor); Bzik, Sara E. (Editor); Rummel, John D. (Editor)

1991-01-01

This symposium was held at the NASA Ames Research Center, Moffett Field, California, July 24-27, 1990. The NASA exobiology investigators reported their recent research findings. Scientific papers were presented in the following areas: cosmic evolution of biogenic compounds, prebiotic evolution (planetary and molecular), early evolution of life (biological and geochemical), evolution of advanced life, solar system exploration, and the Search for Extraterrestrial Intelligence (SETI).

Early life mortality and height in Indian states

PubMed Central

Coffey, Diane

2014-01-01

Height is a marker for health, cognitive ability and economic productivity. Recent research on the determinants of height suggests that postneonatal mortality predicts height because it is a measure of the early life disease environment to which a cohort is exposed. This article advances the literature on the determinants of height by examining the role of early life mortality, including neonatal mortality, in India, a large developing country with a very short population. It uses state level variation in neonatal mortality, postneonatal mortality, and pre-adult mortality to predict the heights of adults born between 1970 and 1983, and neonatal and postneonatal mortality to predict the heights of children born between 1995 and 2005. In contrast to what is found in the literature on developed countries, I find that state level variation in neonatal mortality is a strong predictor of adult and child heights. This may be due to state level variation in, and overall poor levels of, pre-natal nutrition in India. PMID:25499239

The first thousand days - intestinal microbiology of early life: establishing a symbiosis.

PubMed

Wopereis, Harm; Oozeer, Raish; Knipping, Karen; Belzer, Clara; Knol, Jan

2014-08-01

The development of the intestinal microbiota in the first years of life is a dynamic process significantly influenced by early-life nutrition. Pioneer bacteria colonizing the infant intestinal tract and the gradual diversification to a stable climax ecosystem plays a crucial role in establishing host-microbe interactions essential for optimal symbiosis. This colonization process and establishment of symbiosis may profoundly influence health throughout life. Recent developments in microbiologic cultivation-independent methods allow a detailed view of the key players and factors involved in this process and may further elucidate their roles in a healthy gut and immune maturation. Aberrant patterns may lead to identifying key microbial signatures involved in developing immunologic diseases into adulthood, such as asthma and atopic diseases. The central role of early-life nutrition in the developmental human microbiota, immunity, and metabolism offers promising strategies for prevention and treatment of such diseases. This review provides an overview of the development of the intestinal microbiota, its bidirectional relationship with the immune system, and its role in impacting health and disease, with emphasis on allergy, in early life. © 2014 Danone Nutricia Research. Pediatric Allergy and Immunology published by John Wiley & Sons Ltd.

Application of Diversity Indices to Quantify Early Life-History Diversity for Chinook Salmon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Gary E.; Sather, Nichole K.; Skalski, John R.

2014-03-01

We developed an index of early life history diversity (ELHD) for Pacific salmon (Oncorhynchus spp.) Early life history diversity is the variation in morphological and behavioral traits expressed within and among populations by individual juvenile salmon during their downstream migration. A standard quantitative method does not exist for this prominent concept in salmon biology.

The Relationship Between the Origins of Life on Earth and the Possibility of Life on Other Planets: A Nineteenth-Century Perspective

NASA Astrophysics Data System (ADS)

Tirard, Stéphane

In this chapter we examine how, during the second part of the nineteenth century and the beginning of the twentieth century, assumptions about the origins of life were specifically linked to the development of theories of evolution and how these conceptions influenced assumptions about the possibility of life on other planets. First we present the theories of the origins of life of Charles Darwin (1809-1882) and Herbert Spencer (1820-1903) and underline how they were linked to the knowledge of physical and chemical conditions of environments. These two examples lead us to think about the relationship between the origin of life, evolutionary biology, and geology, particularly the uniformitarian principle. An important point is the extension of the comprehension of terrestrial conditions of emergence and evolution of life to other planets. We claim that there was a sort of extended uniformitarian principle, based not only on time, but also on space. Second, after a brief look at panspermia theory, we compare two examples of assumptions about life on other planets. The French astronomer Camille Flammarion (1842-1925) and the French biologist Edmond Perrier (1844-1921) presented views that consisted in complex analogies between life on Earth and life on other planets. We analyze how they used neo-Lamarckian biological concepts to imagine living beings in other worlds. Each planet is characterized by a particular stage of biological evolution that they deduce from the state of living beings on Earth. The two scientists explained these different states with neo-Lamarckian principles, which were based on environmental constraints on organisms. Therefore these descriptions presented a sort of history of life, including the past and the future. We claim that their assumptions could be some intellectual exercises testing neo-Lamarckian theories. Moreover the description of human beings on other planets, and particularly the Martian epianthropus presented by Perrier, were

The effect of early-life stress on airway inflammation in adult mice.

PubMed

Vig, Rattanjeet; Gordon, John R; Thébaud, Bernard; Befus, A Dean; Vliagoftis, Harissios

2010-01-01

Neonatal stress induces permanent physiological changes that may influence the immune system. Early-life stress increases asthma disease severity in children. We investigated the effects of early-life stress on allergic airway inflammation using a murine model of asthma coupled to maternal separation as an early-life stress stimulus. Maternally separated (MS) and unseparated control (CON) mice were sensitized with ovalbumin (OVA) beginning at day 31 after birth. Challenging mice with OVA increased airway hyperresponsiveness (AHR) and the number of inflammatory cells recovered in the bronchoalveolar lavage (BAL), compared to saline-challenged mice. Challenging MS mice with OVA resulted in less total inflammatory cells, eosinophils, interferon-gamma, and interleukin-4 in BAL compared to CON mice. However, MS mice challenged with OVA exhibited AHR similar to CON mice challenged with OVA. In contrast, an enhanced stress protocol (MS+) involving removal of pups from their home cages following the removal of the dam resulted in inflammatory cell accumulation and cytokine levels in the BAL similar to CON mice and higher than MS mice. These findings indicate that the effect of early-life psychological factors on the development of airway inflammatory diseases such as asthma is very complex and depends on the quality of the psychological stress stimulus.

Early life exposure to malaria and cognition in adulthood: evidence from Mexico.

PubMed

Venkataramani, Atheendar S

2012-09-01

This study examines the impact of early life malaria exposure on cognition in sample of Mexican adults, using the nationwide introduction of malaria eradication efforts to identify causal impacts. The core findings are that birth year exposure to malaria eradication was associated with increases in Raven Progressive Matrices test scores and consumption expenditures, but not schooling. Additionally, cohorts born after eradication both entered and exited school earlier than their pre-eradication counterparts. These effects were only seen for men and explanations for this are assessed. Collectively, these findings suggest that improvements in infant health help explain secular increases in cognitive test scores, that better cognition may link early life health to adulthood earnings, and that human capital investments through childhood and young adulthood respond sensitively to market returns to early life endowment shocks. Copyright © 2012 Elsevier B.V. All rights reserved.

Psychological Study on the Origin of Life, Death and Life after Death: Differences between Beliefs According to Age and Schooling

ERIC Educational Resources Information Center

Silva Bautista, Jesús; Herrera Escobar, Venazir; Corona Miranda, Rodolfo

2018-01-01

The present work proposes a psychological study via beliefs, about the origin of life, death, and life after death. Beliefs have played a decisive role in the development of humanity, from the primitive man who gave to the unknown divine forces, the judgments of the Holy Inquisition in the Medieval Age, the impact provoked by the conviction that…

Latent carcinogenicity of early-life exposure to dichloroacetic acid in mice

EPA Science Inventory

AbstractEnvironmental exposures occurring early in life may have an important influence on cancer risk later in life. Here we investigated carryover effects of young-adult exposure to dichloroacetic acid (DCA), a small molecule analog of pyruvate and low-level environmental cont...

Life, Labor, and, Song in New England during the Early Republic.

ERIC Educational Resources Information Center

Scott, John W., Ed.; Scott, John A., Ed.

1998-01-01

Singing the tunes in this collection will help students understand many of the realities of life during the early years of the United States. From hearth and home to the perils of the sea, and from factory life to Presidential elections, this journal offers a selection of 19 songs to introduce the life and labor of New England people during the…

Bulk measurements of messy chemistries are needed for a theory of the origins of life

NASA Astrophysics Data System (ADS)

Guttenberg, Nicholas; Virgo, Nathaniel; Chandru, Kuhan; Scharf, Caleb; Mamajanov, Irena

2017-11-01

A feature of many of the chemical systems plausibly involved in the origins of terrestrial life is that they are complex and messy-producing a wide range of compounds via a wide range of mechanisms. However, the fundamental behaviour of such systems is currently not well understood; we do not have the tools to make statistical predictions about such complex chemical networks. This is, in part, due to a lack of quantitative data from which such a theory could be built; specifically, functional measurements of messy chemical systems. Here, we propose that the pantheon of experimental approaches to the origins of life should be expanded to include the study of `functional measurements'-the direct study of bulk properties of chemical systems and their interactions with other compounds, the formation of structures and other behaviours, even in cases where the precise composition and mechanisms are unknown. This article is part of the themed issue 'Reconceptualizing the origins of life'.

Nutrition in early life, and risk of cancer and metabolic disease: alternative endings in an epigenetic tale?

PubMed Central

Burdge, Graham C; Lillycrop, Karen A; Jackson, Alan A

2008-01-01

There is substantial evidence which shows that constraints in the early life environment is an important determinant of risk of metabolic and cardiovascular disease. There is emerging evidence that higher birth weight, which reflects a more abundant prenatal environment, is associated with increased risk of cancer, in particular breast cancer and childhood leukaemia. Using specific examples from epidemiology and experimental studies, this review discusses the hypothesis that increased susceptibility to cardiovascular, metabolic disease and cancer have a common origin in developmental changes induced in the developing fetus by aspects of the intra uterine environment including nutrition which involve stable changes to the epigenetic regulation of specific genes. However, the induction of specific disease risk is dependent upon the nature of the environmental challenge and interactions between the susceptibility set by the altered epigenome and the environment throughout the life course. PMID:19079817

The origin of dwarf early-type galaxies

NASA Astrophysics Data System (ADS)

Toloba, E.

2013-05-01

We have conducted a spectrophotometric study of dwarf early-type galaxies (dEs) in the Virgo cluster and in regions of lower density. We have found that these galaxies show many properties in common with late-type galaxies but not with more massive early-types (E/S0). The properties of the dEs in Virgo show gradients within the cluster. dEs in the outer parts of the Virgo cluster are kinematically supported by rotation, while those in the center are supported by the random motions of their stars (i.e. pressure supported). The rotationally supported dEs have disky isophotes and faint underlying spiral/irregular substructures, they also show younger ages than those pressure supported, which have boxy isophotes and are smooth and regular, without any substructure. We compare the position of these dEs with massive early-type galaxies in the Faber-Jackson and Fundamental Plane relations, and we find that, although there is no difference between the position of rotationally and pressure supported dEs, both deviate from the relations of massive early-type galaxies in the direction of dwarf spheroidal systems (dSphs). We have used their offset with respect to the Fundamental Plane of E/S0 galaxies to estimate their dark matter fraction. All the properties studied in this work agree with a ram pressure stripping scenario, where late-type galaxies infall into the cluster, their interaction with the intergalactic medium blows away their gas and, as a result, they are quenched in a small amount of time. However, those dEs in the center of the cluster seem to have been fully transformed leaving no trace of their possible spiral origin, thus, if that is the case, they must have experienced a more violent mechanism in combination with ram pressure stripping, the open problem is that even galaxy harassment does not fully explain the observed properties for the pressure supported dEs in the center of the Virgo cluster.

Enhanced transcription and translation in clay hydrogel and implications for early life evolution

PubMed Central

Yang, Dayong; Peng, Songming; Hartman, Mark R.; Gupton-Campolongo, Tiffany; Rice, Edward J.; Chang, Anna Kathryn; Gu, Zi; Lu, G. Q. (Max); Luo, Dan

2013-01-01

In most contemporary life forms, the confinement of cell membranes provides localized concentration and protection for biomolecules, leading to efficient biochemical reactions. Similarly, confinement may have also played an important role for prebiotic compartmentalization in early life evolution when the cell membrane had not yet formed. It remains an open question how biochemical reactions developed without the confinement of cell membranes. Here we mimic the confinement function of cells by creating a hydrogel made from geological clay minerals, which provides an efficient confinement environment for biomolecules. We also show that nucleic acids were concentrated in the clay hydrogel and were protected against nuclease, and that transcription and translation reactions were consistently enhanced. Taken together, our results support the importance of localized concentration and protection of biomolecules in early life evolution, and also implicate a clay hydrogel environment for biochemical reactions during early life evolution. PMID:24196527

Arsenic and Immune Response to Infection During Pregnancy and Early Life

PubMed Central

Attreed, Sarah E.; Navas-Acien, Ana

2017-01-01

Purpose of Review Arsenic, a known carcinogen and developmental toxicant, is a major threat to global health. While the contribution of arsenic exposure to chronic diseases and adverse pregnancy and birth outcomes is recognized, its ability to impair critical functions of humoral and cell-mediated immunity—including the specific mechanisms in humans—is not well understood. Arsenic has been shown to increase risk of infectious diseases that have significant health implications during pregnancy and early life. Here, we review the latest research on the mechanisms of arsenic-related immune response alterations that could underlie arsenic-associated increased risk of infection during the vulnerable periods of pregnancy and early life. Recent Findings The latest evidence points to alteration of antibody production and transplacental transfer as well as failure of T helper cells to produce IL-2 and proliferate. Summary Critical areas for future research include the effects of arsenic exposure during pregnancy and early life on immune responses to natural infection and the immunogenicity and efficacy of vaccines. PMID:28488132

Psychoneuroimmunology of Early-Life Stress: The Hidden Wounds of Childhood Trauma?

PubMed Central

Danese, Andrea; J Lewis, Stephanie

2017-01-01

The brain and the immune system are not fully formed at birth, but rather continue to mature in response to the postnatal environment. The two-way interaction between the brain and the immune system makes it possible for childhood psychosocial stressors to affect immune system development, which in turn can affect brain development and its long-term functioning. Drawing from experimental animal models and observational human studies, we propose that the psychoneuroimmunology of early-life stress can offer an innovative framework to understand and treat psychopathology linked to childhood trauma. Early-life stress predicts later inflammation, and there are striking analogies between the neurobiological correlates of early-life stress and of inflammation. Furthermore, there are overlapping trans-diagnostic patterns of association of childhood trauma and inflammation with clinical outcomes. These findings suggest new strategies to remediate the effect of childhood trauma before the onset of clinical symptoms, such as anti-inflammatory interventions and potentiation of adaptive immunity. Similar strategies might be used to ameliorate the unfavorable treatment response described in psychiatric patients with a history of childhood trauma. PMID:27629365

Assessing Susceptibility from Early-Life Exposure to Carcinogens

PubMed Central

Barton, Hugh A.; Cogliano, V. James; Flowers, Lynn; Valcovic, Larry; Setzer, R. Woodrow; Woodruff, Tracey J.

2005-01-01

Cancer risk assessment methods currently assume that children and adults are equally susceptible to exposure to chemicals. We reviewed available scientific literature to determine whether this was scientifically supported. We identified more than 50 chemicals causing cancer after perinatal exposure. Human data are extremely limited, with radiation exposures showing increased early susceptibility at some tumor sites. Twenty-seven rodent studies for 18 chemicals had sufficient data after postnatal and adult exposures to quantitatively estimate potential increased susceptibility from early-life exposure, calculated as the ratio of juvenile to adult cancer potencies for three study types: acute dosing, repeated dosing, and lifetime dosing. Twelve of the chemicals act through a mutagenic mode of action. For these, the geometric mean ratio was 11 for lifetime exposures and 8.7 for repeat exposures, with a ratio of 10 for these studies combined. The geometric mean ratio for acute studies is 1.5, which was influenced by tissue-specific results [geometric mean ratios for kidney, leukemia, liver, lymph, mammary, nerve, reticular tissue, thymic lymphoma, and uterus/vagina > 1 (range, 1.6–8.1); forestomach, harderian gland, ovaries, and thyroid < 1 (range, 0.033–0.45)]. Chemicals causing cancer through other modes of action indicate some increased susceptibility from postnatal exposure (geometric mean ratio is 3.4 for lifetime exposure, 2.2 for repeat exposure). Early exposures to compounds with endocrine activity sometimes produce different tumors after exposures at different ages. These analyses suggest increased susceptibility to cancer from early-life exposure, particularly for chemicals acting through a mutagenic mode of action. PMID:16140616

Mechanisms for the Formation of Thymine Under Astrophysical Conditions and Implications for the Origin of Life

PubMed Central

Bera, Partha P.; Nuevo, Michel; Materese, Christopher K.; Sandford, Scott A.; Lee, Timothy J.

2018-01-01

Nucleobases are the carriers of the genetic information in RNA and DNA for all life on Earth. Their presence in meteorites clearly indicates that compounds of biological importance can form via non-biological processes in extraterrestrial environments. Recent experimental studies have shown that the pyrimidine-based nucleobases uracil and cytosine can be easily formed from the ultraviolet irradiation of pyrimidine in H2O-rich ice mixtures that simulate astrophysical processes. In contrast, thymine, which is found only in DNA, is more difficult to form under the same experimental conditions, as its formation usually requires a higher photon dose. Earlier quantum chemical studies confirmed that the reaction pathways were favorable provided that several H2O molecules surrounded the reactants. However, the present quantum chemical study shows that the formation of thymine is limited because of the inefficiency of the methylation of pyrimidine and its oxidized derivatives in an H2O ice, as supported by the laboratory studies. Our results constrain the formation of thymine in astrophysical environments and thus the inventory of organic molecules delivered to the early Earth, and have implications for the role of thymine and DNA in the origin of life. PMID:27083722

Mechanisms for the formation of thymine under astrophysical conditions and implications for the origin of life

NASA Astrophysics Data System (ADS)

Bera, Partha P.; Nuevo, Michel; Materese, Christopher K.; Sandford, Scott A.; Lee, Timothy J.

2016-04-01

Nucleobases are the carriers of the genetic information in ribonucleic acid and deoxyribonucleic acid (DNA) for all life on Earth. Their presence in meteorites clearly indicates that compounds of biological importance can form via non-biological processes in extraterrestrial environments. Recent experimental studies have shown that the pyrimidine-based nucleobases uracil and cytosine can be easily formed from the ultraviolet irradiation of pyrimidine in H2O-rich ice mixtures that simulate astrophysical processes. In contrast, thymine, which is found only in DNA, is more difficult to form under the same experimental conditions, as its formation usually requires a higher photon dose. Earlier quantum chemical studies confirmed that the reaction pathways were favorable provided that several H2O molecules surrounded the reactants. However, the present quantum chemical study shows that the formation of thymine is limited because of the inefficiency of the methylation of pyrimidine and its oxidized derivatives in an H2O ice, as supported by the laboratory studies. Our results constrain the formation of thymine in astrophysical environments and thus the inventory of organic molecules delivered to the early Earth and have implications for the role of thymine and DNA in the origin of life.

Positive emotions in early life and longevity: findings from the nun study.

PubMed

Danner, D D; Snowdon, D A; Friesen, W V

2001-05-01

Handwritten autobiographies from 180 Catholic nuns, composed when participants were a mean age of 22 years, were scored for emotional content and related to survival during ages 75 to 95. A strong inverse association was found between positive emotional content in these writings and risk of mortality in late life (p < .001). As the quartile ranking of positive emotion in early life increased, there was a stepwise decrease in risk of mortality resulting in a 2.5-fold difference between the lowest and highest quartiles. Positive emotional content in early-life autobiographies was strongly associated with longevity 6 decades later. Underlying mechanisms of balanced emotional states are discussed.

An exposome perspective: Early-life events and immune development in a changing world.

PubMed

Renz, Harald; Holt, Patrick G; Inouye, Michael; Logan, Alan C; Prescott, Susan L; Sly, Peter D

2017-07-01

Advances in metagenomics, proteomics, metabolomics, and systems biology are providing a new emphasis in research; interdisciplinary work suggests that personalized medicine is on the horizon. These advances are illuminating sophisticated interactions between human-associated microbes and the immune system. The result is a transformed view of future prevention and treatment of chronic noncommunicable diseases, including allergy. Paradigm-shifting gains in scientific knowledge are occurring at a time of rapid global environmental change, urbanization, and biodiversity losses. Multifactorial and multigenerational implications of total environmental exposures, the exposome, require coordinated interdisciplinary efforts. It is clear that the genome alone cannot provide answers to urgent questions. Here we review the historical origins of exposome research and define a new concept, the metaexposome, which considers the bidirectional effect of the environment on human subjects and the human influence on all living systems and their genomes. The latter is essential for human health. We place the metaexposome in the context of early-life immune functioning and describe how various aspects of a changing environment, especially through microbiota exposures, can influence health and disease over the life course. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Early-Life Parent-Child Relationships and Adult Children's Support of Unpartnered Parents in Later Life.

PubMed

Lin, I-Fen; Wu, Hsueh-Sheng

2018-02-08

The proportion of older adults who are unpartnered has increased significantly over the past 25 years. Unpartnered older adults often rely on their adult children for support. Most previous studies have focused on proximal factors associated with adult children's support of their parents, while few have examined distal factors, such as parent-child relationships formed during childhood. This study fills the gap by investigating the direct and indirect associations between early-life parent-child relationships and adult children's upward transfers to unpartnered parents. Data came from two supplements to the Panel Study of Income Dynamics, in which respondents were asked about their relationships with mothers and fathers before age 17 and their transfers of time and money to parents in 2013. Path models were estimated for unpartnered mother-adult child dyads and father-adult child dyads separately. For adult children of unpartnered mothers, psychological closeness has a direct, positive association with time transfer, while physical violence has an indirect association with time transfer through adult children's marital status. For adult children of unpartnered fathers, psychological closeness has neither a direct nor an indirect association with time or money transfer, but physical violence has a direct, negative association with time transfer. Early-life parent-child relationships play a pivotal role in influencing adult children's caregiving behavior, both directly and indirectly. Our findings suggest that by improving their relationships with children early in life, parents may be able to increase the amount of time transfer that they receive in late life. © The Author(s) 2018. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The microbiome in early life: implications for health outcomes.

PubMed

Tamburini, Sabrina; Shen, Nan; Wu, Han Chih; Clemente, Jose C

2016-07-07

Recent studies have characterized how host genetics, prenatal environment and delivery mode can shape the newborn microbiome at birth. Following this, postnatal factors, such as antibiotic treatment, diet or environmental exposure, further modulate the development of the infant's microbiome and immune system, and exposure to a variety of microbial organisms during early life has long been hypothesized to exert a protective effect in the newborn. Furthermore, epidemiological studies have shown that factors that alter bacterial communities in infants during childhood increase the risk for several diseases, highlighting the importance of understanding early-life microbiome composition. In this review, we describe how prenatal and postnatal factors shape the development of both the microbiome and the immune system. We also discuss the prospects of microbiome-mediated therapeutics and the need for more effective approaches that can reconfigure bacterial communities from pathogenic to homeostatic configurations.

Early life experience alters behavior during social defeat: focus on serotonergic systems.

PubMed

Gardner, K L; Thrivikraman, K V; Lightman, S L; Plotsky, P M; Lowry, C A

2005-01-01

Early life experience can have prolonged effects on neuroendocrine, autonomic, and behavioral responses to stress. The objective of this study was to investigate the effects of early life experience on behavior during social defeat, as well as on associated functional cellular responses in serotonergic and non-serotonergic neurons within the dorsal raphe nucleus, a structure which plays an important role in modulation of stress-related physiology and behavior. Male Long Evans rat pups were exposed to either normal animal facility rearing or 15 min or 180 min of maternal separation from postnatal days 2-14. As adults, these rats were exposed to a social defeat protocol. Differences in behavior were seen among the early life treatment groups during social defeat; rats exposed to 180 min of maternal separation from postnatal days 2-14 displayed more passive-submissive behaviors and less proactive coping behaviors. Analysis of the distribution of tryptophan hydroxylase and c-Fos-like immunoreactivity in control rats exposed to a novel cage and rats exposed to social defeat revealed that, independent of the early life experience, rats exposed to social defeat showed an increase in the number of c-Fos-like immunoreactive nuclei in serotonergic neurons in the middle and caudal parts of the dorsal dorsal raphe nucleus and caudal part of the ventral dorsal raphe nucleus, regions known to contain serotonergic neurons projecting to central autonomic and emotional motor control systems. This is the first study to show that the dorsomedial part of the mid-rostrocaudal dorsal raphe nucleus is engaged by a naturalistic stressor and supports the hypothesis that early life experience alters behavioral coping strategies during social conflict; furthermore, this study is consistent with the hypothesis that topographically organized subpopulations of serotonergic neurons principally within the mid-rostrocaudal and caudal part of the dorsal dorsal raphe nucleus modulate stress

The Nun study: clinically silent AD, neuronal hypertrophy, and linguistic skills in early life.

PubMed

Iacono, D; Markesbery, W R; Gross, M; Pletnikova, O; Rudow, G; Zandi, P; Troncoso, J C

2009-09-01

It is common to find substantial Alzheimer disease (AD) lesions, i.e., neuritic beta-amyloid plaques and neurofibrillary tangles, in the autopsied brains of elderly subjects with normal cognition assessed shortly before death. We have termed this status asymptomatic AD (ASYMAD). We assessed the morphologic substrate of ASYMAD compared to mild cognitive impairment (MCI) in subjects from the Nun Study. In addition, possible correlations between linguistic abilities in early life and the presence of AD pathology with and without clinical manifestations in late life were considered. Design-based stereology was used to measure the volumes of neuronal cell bodies, nuclei, and nucleoli in the CA1 region of hippocampus (CA1). Four groups of subjects were compared: ASYMAD (n = 10), MCI (n = 5), AD (n = 10), and age-matched controls (n = 13). Linguistic ability assessed in early life was compared among all groups. A significant hypertrophy of the cell bodies (+44.9%), nuclei (+59.7%), and nucleoli (+80.2%) in the CA1 neurons was found in ASYMAD compared with MCI. Similar differences were observed with controls. Furthermore, significant higher idea density scores in early life were observed in controls and ASYMAD group compared to MCI and AD groups. 1) Neuronal hypertrophy may constitute an early cellular response to Alzheimer disease (AD) pathology or reflect compensatory mechanisms that prevent cognitive impairment despite substantial AD lesions; 2) higher idea density scores in early life are associated with intact cognition in late life despite the presence of AD lesions.

Alfonso Luis Herrera and the Beginnings of Evolutionism and Studies in the Origin of Life in Mexico.

PubMed

Ledesma-Mateos, Ismael; Cleaves, H James

2016-12-01

Alfonso Luis Herrera (1868-1942) was a Mexican biologist, and significant as the principal promoter of Darwinian thought in that country. However, Herrera's thinking went beyond the evolution of living beings, and extended to the question of the origin of life itself and the place of living phenomena in the larger context of the cosmos. Perhaps more significantly, though now largely forgotten, Herrera was among the first to embark on an experimental program to understand the origin of life, one which may be seen as foundational for later workers, most notably Sidney Fox and Alexander Oparin, and which has been resuscitated recently. We review here the development of Herrera's scientific thought on Darwinism and the origin of life and the context in which it developed.

Revealing the origin of the cold ISM in massive early-type galaxies

NASA Astrophysics Data System (ADS)

Davis, T. A.; Alatalo, K.; Bureau, M.; Young, L.; Blitz, L.; Crocker, A.; Bayet, E.; Bois, M.; Bournaud, F.; Cappellari, M.; Davies, R. L.; Duc, P.-A.; de Zeeuw, P. T.; Emsellem, E.; Falcon-Barroso, J.; Khochfar, S.; Krajnovic, D.; Kuntschner, H.; Lablanche, P.-Y.; McDermid, R. M.; Morganti, R.; Naab, T.; Sarzi, M.; Scott, N.; Serra, P.; Weijmans, A.

2013-07-01

Recently, massive early-type galaxies have shed their red-and-dead moniker, thanks to the discovery that many host residual star formation. As part of the ATLAS-3D project, we have conducted a complete, volume-limited survey of the molecular gas in 260 local early-type galaxies with the IRAM-30m telescope and the CARMA interferometer, in an attempt to understand the fuel powering this star formation. We find that around 22% of early-type galaxies in the local volume host molecular gas reservoirs. This detection rate is independent of galaxy luminosity and environment. Here we focus on how kinematic misalignment measurements and gas-to-dust ratios can be used to put constraints on the origin of the cold ISM in these systems. The origin of the cold ISM seems to depend strongly on environment, with misaligned, dust poor gas (indicative of externally acquired material) being common in the field but completely absent in rich groups and in the Virgo cluster. Very massive galaxies also appear to be devoid of accreted gas. This suggests that in the field mergers and/or cold gas accretion dominate the gas supply, while in clusters internal secular processes become more important. This implies that environment has a strong impact on the cold gas properties of ETGs.

The origins, early development and status of Bourdieu's concept of 'cultural capital'.

PubMed

Robbins, Derek

2005-03-01

The paper examines the context of the first introduction of the concept of 'cultural capital' in the sociology of education analyses undertaken in the early 1960s and published by Bourdieu in collaboration with Jean-Claude Passeron in 'Les etudiants et leurs etudes' (1964a) and Les Heritiers (1964b). It first considers the cultural contexts within which Bourdieu's thinking about culture originated--both in relation to his social origins and in relation to his intellectual training. It then examines the extent to which Bourdieu's early anthropological research in Algeria was influenced by his knowledge of American acculturation theory. It concludes that Bourdieu sought to use acculturation theory in a distinctive way--one which he articulated more confidently as he explored the relationship between agency and structural explanation in the late 1960s and early 1970s. The specific educational researches which stimulated the articulation of the concept of 'linguistic' or 'cultural' capital belonged to the period in which Bourdieu was only just beginning to refine his post-structuralist philosophy of social scientific explanation. To use these concepts now involves deploying them reflexively in accordance with Bourdieu's later thinking rather than at face value as they were first developed during the period in which he and Passeron were 'apprentice' researchers.

Effects of early-life malnutrition on neurodevelopment and neuropsychiatric disorders and the potential mechanisms.

PubMed

Yan, Xintian; Zhao, Xinzhi; Li, Juxue; He, Lin; Xu, Mingqing

2018-04-20

Lines of evidence have demonstrated that early-life malnutrition is highly correlated with neurodevelopment and adulthood neuropsychiatric disorders, while some findings are conflicting with each other. In addition, the biological mechanisms are less investigated. We systematically reviewed the evidence linking early-life nutrition status with neurodevelopment and clinical observations in human and animal models. We summarized the effects of special nutritious on neuropsychiatric disorders and explored the underlying potential mechanisms. The further understanding of the biological regulation of early-life nutritional status on neurodevelopment might shed light on precision nutrition at an integrative systems biology framework. Copyright © 2018 Elsevier Inc. All rights reserved.

Innate Immunity to Respiratory Infection in Early Life

PubMed Central

Lambert, Laura; Culley, Fiona J.

2017-01-01

Early life is a period of particular susceptibility to respiratory infections and symptoms are frequently more severe in infants than in adults. The neonatal immune system is generally held to be deficient in most compartments; responses to innate stimuli are weak, antigen-presenting cells have poor immunostimulatory activity and adaptive lymphocyte responses are limited, leading to poor immune memory and ineffective vaccine responses. For mucosal surfaces such as the lung, which is continuously exposed to airborne antigen and to potential pathogenic invasion, the ability to discriminate between harmless and potentially dangerous antigens is essential, to prevent inflammation that could lead to loss of gaseous exchange and damage to the developing lung tissue. We have only recently begun to define the differences in respiratory immunity in early life and its environmental and developmental influences. The innate immune system may be of relatively greater importance than the adaptive immune system in the neonatal and infant period than later in life, as it does not require specific antigenic experience. A better understanding of what constitutes protective innate immunity in the respiratory tract in this age group and the factors that influence its development should allow us to predict why certain infants are vulnerable to severe respiratory infections, design treatments to accelerate the development of protective immunity, and design age specific adjuvants to better boost immunity to infection in the lung. PMID:29184555

Understanding Early Decisions to Withdraw Life-Sustaining Therapy in Cardiac Arrest Survivors. A Qualitative Investigation.

PubMed

Dale, Craig M; Sinuff, Tasnim; Morrison, Laurie J; Golan, Eyal; Scales, Damon C

2016-07-01

Early withdrawal of life-sustaining therapy contributes to the majority of deaths following out-of-hospital cardiac arrest (OHCA), despite current recommendations for delayed neurological prognostication (≥72 h) after treatment with targeted temperature management. Little is known about clinicians' experiences of early withdrawal of life support decisions in patients with OHCA. To explore clinicians' experiences and perceptions of early withdrawal of life support decisions and barriers to guideline-concordant neurological prognostication in comatose survivors of OHCA treated with targeted temperature management. We conducted qualitative interviews with intensive care unit (ICU) physicians and nurses following withdrawal of life support in comatose patients with OHCA treated with targeted temperature management. The study was carried out across 18 academic and community hospitals participating in a multicenter, stepped-wedge, cluster-randomized controlled trial designed to improve quality-of-care processes for patients after OHCA in Ontario, Canada. We used a focused thematic analysis to capture barriers to guideline-concordant neurological prognostication and used these barriers to identify potentially modifiable issues. The core thematic finding was a high emotional burden of ICU family-team communication in which strong feelings inhibited information transfer and delayed decision making following OHCA. Four subthemes describing sources of communication strain were identified: (1) requests from family members to provide early outcome predictions, (2) incomplete family comprehension of critical care, (3) family requests for early withdrawal of life support based on their understanding of patients' preferences and values, and (4) family-team communication gaps related to prognostic uncertainty. Participants worried that gaps in timely and clear prognostic information contributed to surrogates' perceptions of a poor outcome and to inappropriately early decisions to

Humic First Theory: A New Theory on the Origin of Life

NASA Astrophysics Data System (ADS)

Daei, Mohammad Ali; Daei, Manijeh; Daei, Bijan

2017-04-01

In 1953, Miller & Urey through a brilliant experiment demonstrated that the building blocks of life could evolve in primitive earth conditions [1]. During the recent years scientists revealed that organic matters are not very rare compounds in comets, asteroids, and meteorites which have bombarded the ancient earth repeatedly [2]. So simple organic molecules on early earth could be quite enough to start chemical evolution and steadily, proceeded to the very simple form of life. Many theories have tried to explain how life emerged from non life, but failed, largely due to the lack of a distinct methodology. There is a huge gap between the simple building blocks, like amino acid, sugar, and lipid molecules, to a living cell with a very sophisticated structure and organization. It is unacceptable to fill this great distance, only by accidental reactions in a passive media (primitive soap) even, over a very long time. Obviously, manufacturing of a primitive cell required a natural factory with rather firm and resistant basement, plenty of organic and inorganic raw materials and qualified production line, plus some sources of energy. There were plenty of solar energy and water in the early Earth, but what about the other factors? Availability of essential minerals was not guaranteed at all, in primitive earth which covered with bare, dead rocks. While we are not able today, to multiply any microorganisms in ideal conditions of modern laboratory in the absence of only one of essential nutrients or elements, how can we expect primitive cells appear on early earth conditions without the support of soluble minerals and organic matters? Ideal production line must be active and protective, have catalyzing ability, could provide numerous opportunities for interaction between basic bio molecules (mainly RNA and proteins) and above all, have capability to react with different sources of energy. There are strong evidences that show only some form of stable, rich and active

Early-Life Stressors, Personality Development, and Fast Life Strategies: An Evolutionary Perspective on Malevolent Personality Features.

PubMed

Csathó, Árpád; Birkás, Béla

2018-01-01

Life history theory posits that behavioral adaptation to various environmental (ecological and/or social) conditions encountered during childhood is regulated by a wide variety of different traits resulting in various behavioral strategies. Unpredictable and harsh conditions tend to produce fast life history strategies, characterized by early maturation, a higher number of sexual partners to whom one is less attached, and less parenting of offspring. Unpredictability and harshness not only affects dispositional social and emotional functioning, but may also promote the development of personality traits linked to higher rates of instability in social relationships or more self-interested behavior. Similarly, detrimental childhood experiences, such as poor parental care or high parent-child conflict, affect personality development and may create a more distrustful, malicious interpersonal style. The aim of this brief review is to survey and summarize findings on the impact of negative early-life experiences on the development of personality and fast life history strategies. By demonstrating that there are parallels in adaptations to adversity in these two domains, we hope to lend weight to current and future attempts to provide a comprehensive insight of personality traits and functions at the ultimate and proximate levels.