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Sample records for earliest life natural

  1. Reassessing the Evidence for the Earliest Traces of Life

    NASA Technical Reports Server (NTRS)

    vanZullen, Mark A.; Lepland, Alve; Arrhenlus, Gustaf

    2002-01-01

    The isotopic composition of graphite is commonly used as a biomarker in the oldest (>3.5 Gyr ago) highly metamorphosed terrestrial rocks. Earlier studies on isotopic characteristics of graphite occurring in rocks of the approximately 3.8-Gyr-old Isua supracrustal belt (ISB) in southern West Greenland have suggested the presence of a vast microbial ecosystem in the early Archean. This interpretation, however, has to be approached with extreme care. Here we show that graphite occurs abundantly in secondary carbonate veins in the ISB that are formed at depth in the crust by injection of hot fluids reacting with older crustal rocks (metasomatism). During these reactions, graphite forms from the disproportionation of Fe(II)-bearing carbonates at high temperature. These metasomatic rocks, which clearly lack biological relevance, were earlier thought to be of sedimentary origin and their graphite association provided the basis for inferences about early life. The new observations thus call for a reassessment of previously presented evidence for ancient traces of life in the highly metamorphosed Early Archaean rock record.

  2. Density-dependent settlement and mortality structure the earliest life phases of a coral population.

    PubMed

    Vermeij, Mark J A; Sandin, Stuart A

    2008-07-01

    The local densities of heterospecifics and conspecifics are known to have profound effects on the dynamics of many benthic species, including rates of settlement and early post-settlement survivorship. We described the early life history of the Caribbean coral, Siderastrea radians by tracking the population dynamics from recently settled planulae to juveniles. Through three years of observation, settlement correlated with the abundance of other benthic organisms, principally turf algae (negatively) and crustose coralline algae (positively). In addition, adult density showed independent effects on coral settlement and early post-settlement survivorship. Settlement rates increased across low levels of adult cover and saturated at a maximum around 10% cover. Early post-settlement survivorship decreased with adult cover, revealing structuring density dependence in coral settlers. The earliest life stages of corals are defined by low survivorship, with survivorship increasing appreciably with colony size. However, recent settlers (one-polyp individuals, < 1-year-old) are more likely to grow into two-polyp juveniles than older single polyps (> 1-year-old) that were delayed in their development. The early benthic phase of corals is defined by a severe demographic bottleneck for S. radians, with appreciable density-dependent and density-independent effects on survivorship. For effective management and restoration of globally imperiled coral reefs, we must focus more attention on this little studied, but dynamic, early life history period of corals. PMID:18705385

  3. The Earliest Fossil Evidence for Life on Land and the Freshwater Origin of Algae?

    NASA Astrophysics Data System (ADS)

    Battison, L.; Brasier, M. D.; Antcliffe, J. B.

    2009-04-01

    Some 150 years ago, in 1859, Charles Darwin was greatly puzzled by a seeming absence of fossils in rocks older than the Cambrian period. He drew attention to a veritable Lost World that it is now known to have spanned more than 80 per cent of Earth History. And he made a prediction that we here bring again into focus: 'The presence of phosphate nodules and bituminous matter in some of the lowest azoic rocks probably indicates the former existence of life at these periods (Darwin 1859, p.307). His prediction came to fruition in 1899, when Sir Archibald Geikie announced to the world the first discovery of genuine microfossils in Precambrian phosphatic rocks, made by Jephro Teall, Ben Peach and John Horne within the Torridonian rocks of Scotland. The Torridonian phosphate of NW Scotland has, however, been rather little studied until recently. It is remarkable for its fidelity of fossil preservation, and also for its non-marine depositional setting. Dating to the end of the Mesoproterozoic Era around 1Ga ago, thick packages of fluvial sandstones are found to serve the remains of very ancient intermontane lake ecosystems. Fossil assemblages from terrestrial settings are rarely seen before the Devonian ~ 350 Ma ago. Evidence for freshwater and terrestrial life in the Precambrian has therefore been circumstantial rather than detailed and none has yet come from freshwater phosphate. We here demonstrate that phosphate from ~ 1200-1000 Ma Mesoproterozoic lake sediments of the Torridon Group preserve a remarkable suite of organisms forming a freshwater, terrestrial, phototrophic ecosystem. Ephemeral lakes and streams developed in intermontane basins within the interior of the supercontinent of Rodinia and periodically experienced prolonged desiccation allowing phosphate precipitation. The microbiology of these lake sediments is being studied in detail, where they are yielding - with the aid of Automontage - fresh evidence for the earliest known terrestrial ecology and

  4. Evaluating the earliest traces of Archean sub-seafloor life by NanoSIMS

    NASA Astrophysics Data System (ADS)

    Mcloughlin, N.; Grosch, E. G.; Kilburn, M.; Wacey, D.

    2012-12-01

    The Paleoarchean sub-seafloor has been proposed as an environment for the emergence of life with titanite microtextures in pillow lavas argued to be the earliest traces of microbial micro-tunneling (Furnes et al. 2004). Here we use a nano-scale ion microprobe (NanoSIMS) to evaluate possible geochemical traces of life in 3.45 Ga pillow lavas of the Barberton Greenstone Belt, South Africa. We investigated both surface and drill core samples from the original "Biomarker" outcrop in the Hooggenoeg Fm. Pillow lava metavolcanic glass contain clusters of segmented microcrystalline titanite filaments, ~4μm across and <200μm in length. Their size, shape and distribution have been directly compared to those found in recent oceanic crust. Thus it has been argued that they are the mineralized remains of tunnels formed by microbes that etched volcanic glass in the Archean sub-seafloor (Furnes et al 2004; Banerjee et al. 2006). Elemental mapping by NanoSIMS was undertaken to investigate reports of enrichments in carbon (possibly also nitrogen) along the margins of the microtextures previously interpreted as decayed cellular remains. We mapped for 12C-, 26CN-, 32S- along with 16O-, 28Si-, 24Mg+,27Al+, 40Ca+, 48Ti+ and 56Fe+ in chlorite and quartz hosted examples. The 12C- or 26CN- linings were not found along the margins of the microtextures in neither the original, nor the drill core samples, despite NanoSIMS being a more sensitive and higher-spatial-resolution technique than earlier microprobe X-ray maps. The absence of organic linings in these samples excludes a key line of evidence previously used to support the biogenicity of the microtextures. Sulfur isotopes 32S and 34S were measured by NanoSIMS on two types of sulfide: i) small sulfides (1-15μm) intimately associated with the microtextures and; ii) larger sulfides (10-60μm) that cross-cut the microtextures and are disseminated near a quartz-carbonate vein. The sulfide inclusions in the microtextures have strongly

  5. Abiotic Earth - Establishing a Baseline for Earliest Life, Data from the Archean of Western Australia

    NASA Technical Reports Server (NTRS)

    Lindsay, J. F.; Brasier, M. D.; McLoughlin, N.; Green, O. R.; Fogel, M.; McNamara, K. M.; Steele, A.; Mertzman, S. A.

    2003-01-01

    Stromatolitic structures preserved at two stratigraphic levels within the 3.47-3.43 Ga Warrawoona Group of Western Australia have been interpreted as some of "the least controversial evidence of early life on earth" and "the oldest firmly established biogenic deposits now known from the geologic record". The structures were said to have formed in a shallow sub-tidal to intertidal setting as part of an evaporite succession. In an extensive field program we have re-evaluated exposures of the Strelley Pool Chert from which stromatolites have been described and carried out detailed mapping and sampling of the Strelley Pool West site 13.7 km west of the type locality. Data from our ongoing program cast considerable doubt on the biogenic origins of the stromatolitic structures and on the nature of their depositional setting.

  6. Functional Capabilities of the Earliest Peptides and the Emergence of Life

    PubMed Central

    Milner-White, E. James; Russell, Michael J.

    2011-01-01

    Considering how biological macromolecules first evolved, probably within a marine environment, it seems likely the very earliest peptides were not encoded by nucleic acids, or at least not via the genetic code as we know it. An objective of the present work is to demonstrate that sequence-independent peptides, or peptides with variable and unreliable lengths and sequences, have the potential to perform a variety of chemically useful functions such as anion and cation binding and membrane and channel formation as well as simple types of catalysis. These functions tend to be performed with the assistance of the main chain CONH atoms rather than the more variable or limited side chain atoms of the peptides presumed to exist then. PMID:24710286

  7. The breath of life: an essay on the earliest history of respiration: part ii.

    PubMed

    Gandevia, B

    1970-06-01

    It is to ancient Greek civilization that we must look for the first groping steps towards a naturalistic concept of respiration, although we shall not, of course, expect to find one which is consistent with modern views. Nearly a millennium before Christ, Homer wrote of the gods as more less predictable and very human beings, deserving more of admiration and emulation than worship; they took a fairly commonsense view of man's earthly pursuits, and left him a measure of control over his own destiny. From this relatively disrespectful state-by comparison with primitive or Old Testament views-it is but a stage to a rationalistic view of the universe, that is, to science, and this step was taken about three centuries later (6th century B.C.) by Thales, Anaximander and Anaximenes. We cannot pause to consider their views in detail, nor can we digress, as strictly we should, to consider the emerging relationship between philosophy and science. Suffice it to say that these first philosopher-scientists sought to explain the universe and life in rational terms, basing their rationalizations-we might say extrapolations-on certain specific observations of natural phenomena. The latter were concerned, in the main, with the interrelationships of basic substances (ultimately regarded as the four elements) such as fire, earth, air and water. Water, for example, could be condensed to form earth, or rarefied to form mist and vapour. PMID:25028124

  8. A hypothesis about cellular signaling with nitric oxide in the earliest life forms in evolution.

    PubMed

    Murad, Ferid; Barber, Roger

    2009-11-01

    We propose that nitric oxide participated as an extracellular and intracellular messenger in the early evolution of life. From a toxic and noxious substance it evolved into an important material for cellular communication and regulation with unique chemistry and properties. The presence of some nitric oxide complexes in extraterrestrial samples may support evidence for life forms in the past or present. Although nitric oxide probably participated in the evolution and maintenance of life, if pollution continues at an ever-increasing rate, it could also end life on the planet as we know it today. PMID:19439177

  9. Metasomatic origin of quartz-pyroxene rock, Akilia, Greenland, and implications for Earth's earliest life.

    PubMed

    Fedo, Christopher M; Whitehouse, Martin J

    2002-05-24

    A quartz-pyroxene rock interpreted as a banded iron formation (BIF) from the island of Akilia, southwest Greenland, contains (13)C-depleted graphite that has been claimed as evidence for the oldest (>3850 million years ago) life on Earth. Field relationships on Akilia document multiple intense deformation events that have resulted in parallel transposition of Early Archean rocks and significant boudinage, the tails of which commonly form the banding in the quartz-pyroxene rock. Geochemical data possess distinct characteristics consistent with an ultramafic igneous, not BIF, protolith for this lithology and the adjacent schists. Later metasomatic silica and iron introduction have merely resulted in a rock that superficially resembles a BIF. An ultramafic igneous origin invalidates claims that the carbon isotopic composition of graphite inclusions represents evidence for life at the time of crystallization. PMID:12029129

  10. Identification of candidate molecules for the building blocks of life's earliest polymers

    NASA Astrophysics Data System (ADS)

    Hud, Nicholas

    2016-07-01

    Chemists have yet to find a plausible prebiotic route to RNA polymers, and most proposed mechanisms for prebiotic peptide synthesis are inefficient. We are exploring the hypothesis that RNA and peptides have both evolved from polymers with different chemical structures. We have found that molecules closely related to amino acids and the nucleobases of RNA, which were likely present on the prebiotic Earth, greatly facilitate the formation of polypeptides and RNA-like structures (Chen et al., 2014; Forsythe et al., 2015). The identification of molecules that may have served as precursors to the building blocks of extant polymers, or as prebiotic catalysts for biopolymer formation, has direct implications regarding which molecules that should be considered as possible signs of chemistries that can support the emergence of life in the universe. Furthermore, the possibility that life started with molecules that can be repeatedly cycled between their monomeric and polymeric states, as is still the case with extant biopolymers, suggests environmental characteristics that would have facilitated the formation and early evolution of functional biopolymers (Walker et al., 2012). M. C. Chen, et al., J. Am. Chem. Soc., 2014, 136, 5640-5646 J. G. Forsythe, et al., Angew. Chem., Int. Ed. Engl., 2015, 54, 9871-9875. M.A. Walker, et al., PLoS ONE, 2012, 7, e34166.

  11. Web life: Ask Nature

    NASA Astrophysics Data System (ADS)

    2012-11-01

    Ask Nature is a site devoted to biomimicry, an interdisciplinary field in which practitioners study how animals and plants solve problems, and then use those solutions to develop better human technologies.

  12. From the Earliest Evidence of Life to Complex Single-cell Organisms: The First 3 Gyr on Earth

    NASA Astrophysics Data System (ADS)

    Buick, Roger

    2006-12-01

    Life has probably been present on Earth since the time of the oldest sedimentary rock record 3.8 Gyr ago, as indicated by graphite with light carbon isotope ratios consistent with derivation from organic matter. But certain evidence for life appears only at 3.52 Gyr, in the form of kerogen (insoluble organic matter) in sedimentary carbonate showing a -25‰ carbon isotope fractionation identical to that imparted by biological carbon fixation. Soon after, at 3.48 Gyr, the first visible evidence for life appears as stromatolites (sediment mounds constructed by microbes), as well as the first evidence for a specific metabolism (large negative sulfur isotope fractionations indicating microbial sulfate reduction). By 2.7 Gyr ago, molecular biomarkers (hydrocarbons derived from biomolecules with distinctive carbon skeletons such as steroids) indicate that all 3 Domains of life: bacteria, eukaryotes (organisms with compartmentalized cells like us) and archaea (bacteria-like organisms with different biochemistry, often inhabiting extreme environments); had evolved. The first multicellular eukaryotes appeared by 1.84 Gyr in the form of fossilized filamentous algae, after the atmosphere changed from anoxic to moderately oxygenated at 2.4 Gyr and following a series of extreme “Snowball Earth” glaciations between 2.4-2.2 Gyr. Planktonic algae diversified thereafter and modern algal groups arose 1.2 Gyr ago, apparently at the end of a prolonged period of ocean anoxia when the deep sea was sulfidic and presumably toxic. Animal evolution was delayed until 0.65 Gyr ago when biomarkers for sponges first appear in the record, evidently after a further rise in atmospheric oxygen to modern levels but surprisingly pre-dating the last of another series of “Snowball Earth” glaciations. These sponges co-existed with an enigmatic extinct group of large flat marine organisms called “Ediacaran fossils” that may have been ancestral to modern animal groups but might also have been

  13. The physical nature of life.

    PubMed

    Kalmijn, Ad J; Gonzalez, Ivan Fernando; McClune, Michael C

    2002-01-01

    Life evolved from the primeval world of physics. Sensory systems inform animals of the natural environment, enabling them to conduct responsively. The discovery of weak, DC bioelectric fields in the vicinity of aquatic organisms and the role they play in guiding sharks and rays to their prey have led to the recognition of fundamental, hitherto less well known, physical aspects of sensory biology. The inferred cybernetic algorithm of electric-field orientation in sharks and rays is highly effective and extremely robust. In orienting to the weak DC electric fields of ocean currents and to the earth's magnetic field, sharks and rays unwittingly practise the motional-electric principles that Einstein had in mind when he introduced the special theory of relativity. At the sense-organ, receptor-membrane, and ion-channel levels, the elasmobranch ampullae of Lorenzini operate on the basis of graded positive feedback driven by negative conductance, supposedly employing voltage-sensitive ion channels as the active, excitable elements. The electric sense of sharks and rays presents an exquisite implementation of the very biophysical principles that also govern the graded, much richer than all-or-none, integrative brain processes of animal and man. PMID:14692484

  14. Geological constraints on detecting the earliest life on Earth: a perspective from the Early Archaean (older than 3.7 Gyr) of southwest Greenland

    PubMed Central

    Fedo, Christopher M; Whitehouse, Martin J; Kamber, Balz S

    2006-01-01

    At greater than 3.7 Gyr, Earth's oldest known supracrustal rocks, comprised dominantly of mafic igneous with less common sedimentary units including banded iron formation (BIF), are exposed in southwest Greenland. Regionally, they were intruded by younger tonalites, and then both were intensely dynamothermally metamorphosed to granulite facies (the highest pressures and temperatures generally encountered in the Earth's crust during metamorphism) in the Archaean and subsequently at lower grades until about 1500 Myr ago. Claims for the first preserved life on Earth have been based on the occurrence of greater than 3.8 Gyr isotopically light C occurring as graphite inclusions within apatite crystals from a 5 m thick purported BIF on the island of Akilia. Detailed geologic mapping and observations there indicate that the banding, first claimed to be depositional, is clearly deformational in origin. Furthermore, the mineralogy of the supposed BIF, being dominated by pyroxene, amphibole and quartz, is unlike well-known BIF from the Isua Greenstone Belt (IGB), but resembles enclosing mafic and ultramafic igneous rocks modified by metasomatism and repeated metamorphic recrystallization. This scenario parsimoniously links the geology, whole-rock geochemistry, 2.7 Gyr single crystal zircon ages in the unit, an approximately 1500 Myr age for apatites that lack any graphite, non-MIF sulphur isotopes in the unit and an inconclusive Fe isotope signature. Although both putative body fossils and carbon-12 enriched isotopes in graphite described at Isua are better explained by abiotic processes, more fruitful targets for examining the earliest stages in the emergence of life remain within greater than 3.7 Gyr IGB, which preserves BIF and other rocks that unambiguously formed at Earth's surface. PMID:16754603

  15. Geological constraints on detecting the earliest life on Earth: a perspective from the Early Archaean (older than 3.7 Gyr) of southwest Greenland.

    PubMed

    Fedo, Christopher M; Whitehouse, Martin J; Kamber, Balz S

    2006-06-29

    At greater than 3.7 Gyr, Earth's oldest known supracrustal rocks, comprised dominantly of mafic igneous with less common sedimentary units including banded iron formation (BIF), are exposed in southwest Greenland. Regionally, they were intruded by younger tonalites, and then both were intensely dynamothermally metamorphosed to granulite facies (the highest pressures and temperatures generally encountered in the Earth's crust during metamorphism) in the Archaean and subsequently at lower grades until about 1500 Myr ago. Claims for the first preserved life on Earth have been based on the occurrence of greater than 3.8 Gyr isotopically light C occurring as graphite inclusions within apatite crystals from a 5 m thick purported BIF on the island of Akilia. Detailed geologic mapping and observations there indicate that the banding, first claimed to be depositional, is clearly deformational in origin. Furthermore, the mineralogy of the supposed BIF, being dominated by pyroxene, amphibole and quartz, is unlike well-known BIF from the Isua Greenstone Belt (IGB), but resembles enclosing mafic and ultramafic igneous rocks modified by metasomatism and repeated metamorphic recrystallization. This scenario parsimoniously links the geology, whole-rock geochemistry, 2.7 Gyr single crystal zircon ages in the unit, an approximately 1500 Myr age for apatites that lack any graphite, non-MIF sulphur isotopes in the unit and an inconclusive Fe isotope signature. Although both putative body fossils and carbon-12 enriched isotopes in graphite described at Isua are better explained by abiotic processes, more fruitful targets for examining the earliest stages in the emergence of life remain within greater than 3.7 Gyr IGB, which preserves BIF and other rocks that unambiguously formed at Earth's surface. PMID:16754603

  16. The Earliest Ion Channels

    NASA Astrophysics Data System (ADS)

    Pohorille, A.; Wilson, M. A.; Wei, C.

    2009-12-01

    Supplying protocells with ions required assistance from channels spanning their membrane walls. The earliest channels were most likely short proteins that formed transmembrane helical bundles surrounding a water-filled pore. These simple aggregates were capable of transporting ions with efficiencies comparable to those of complex, contemporary ion channels. Channels with wide pores exhibited little ion selectivity but also imposed only modest constraints on amino acid sequences of channel-forming proteins. Channels with small pores could have been selective but also might have required a more precisely defined sequence of amino acids. In contrast to modern channels, their protocellular ancestors had only limited capabilities to regulate ion flux. It is postulated that subsequent evolution of ion channels progressed primarily to acquire precise regulation, and not high efficiency or selectivity. It is further proposed that channels and the surrounding membranes co-evolved.

  17. The earliest matches.

    PubMed

    Goren-Inbar, Naama; Freikman, Michael; Garfinkel, Yosef; Goring-Morris, A Nigel; Goring-Morris, Nigel A; Grosman, Leore

    2012-01-01

    Cylindrical objects made usually of fired clay but sometimes of stone were found at the Yarmukian Pottery Neolithic sites of Sha'ar HaGolan and Munhata (first half of the 8(th) millennium BP) in the Jordan Valley. Similar objects have been reported from other Near Eastern Pottery Neolithic sites. Most scholars have interpreted them as cultic objects in the shape of phalli, while others have referred to them in more general terms as "clay pestles," "clay rods," and "cylindrical clay objects." Re-examination of these artifacts leads us to present a new interpretation of their function and to suggest a reconstruction of their technology and mode of use. We suggest that these objects were components of fire drills and consider them the earliest evidence of a complex technology of fire ignition, which incorporates the cylindrical objects in the role of matches. PMID:22870306

  18. The Earliest Matches

    PubMed Central

    Goren-Inbar, Naama; Freikman, Michael; Garfinkel, Yosef; Goring-Morris, Nigel A.; Grosman, Leore

    2012-01-01

    Cylindrical objects made usually of fired clay but sometimes of stone were found at the Yarmukian Pottery Neolithic sites of Sha‘ar HaGolan and Munhata (first half of the 8th millennium BP) in the Jordan Valley. Similar objects have been reported from other Near Eastern Pottery Neolithic sites. Most scholars have interpreted them as cultic objects in the shape of phalli, while others have referred to them in more general terms as “clay pestles,” “clay rods,” and “cylindrical clay objects.” Re-examination of these artifacts leads us to present a new interpretation of their function and to suggest a reconstruction of their technology and mode of use. We suggest that these objects were components of fire drills and consider them the earliest evidence of a complex technology of fire ignition, which incorporates the cylindrical objects in the role of matches. PMID:22870306

  19. Natural products in modern life science.

    PubMed

    Bohlin, Lars; Göransson, Ulf; Alsmark, Cecilia; Wedén, Christina; Backlund, Anders

    2010-06-01

    questions in Nature can be of value to increase the attraction for young students in modern life science. PMID:20700376

  20. Natural products in modern life science

    PubMed Central

    Göransson, Ulf; Alsmark, Cecilia; Wedén, Christina; Backlund, Anders

    2010-01-01

    questions in Nature can be of value to increase the attraction for young students in modern life science. PMID:20700376

  1. The earliest pigeon fanciers.

    PubMed

    Blasco, Ruth; Finlayson, Clive; Rosell, Jordi; Marco, Antonio Sánchez; Finlayson, Stewart; Finlayson, Geraldine; Negro, Juan José; Pacheco, Francisco Giles; Vidal, Joaquín Rodríguez

    2014-01-01

    Feral Pigeons have colonised all corners of the Earth, having developed a close association with humans and their activities. The wild ancestor of the Feral Pigeon, the Rock Dove, is a species of rocky habitats, nesting typically on cliff ledges and at the entrance to large caves. This habit would have brought them into close contact with cave-dwelling humans, a relationship usually linked to the development of dwellings in the Neolithic. We show that the association between humans and Rock Doves is an ancient one with its roots in the Palaeolithic and predates the arrival of modern humans into Europe. At Gorham's Cave, Gibraltar, the Neanderthals exploited Rock Doves for food for a period of over 40 thousand years, the earliest evidence dating to at least 67 thousand years ago. We show that the exploitation was not casual or sporadic, having found repeated evidence of the practice in different, widely spaced, temporal contexts within the cave. Our results point to hitherto unappreciated capacities of the Neanderthals to exploit birds as food resources on a regular basis. More so, they were practising it long before the arrival of modern humans and had therefore invented it independently. PMID:25101932

  2. The earliest pigeon fanciers

    PubMed Central

    Blasco, Ruth; Finlayson, Clive; Rosell, Jordi; Marco, Antonio Sánchez; Finlayson, Stewart; Finlayson, Geraldine; Negro, Juan José; Pacheco, Francisco Giles; Vidal, Joaquín Rodríguez

    2014-01-01

    Feral Pigeons have colonised all corners of the Earth, having developed a close association with humans and their activities. The wild ancestor of the Feral Pigeon, the Rock Dove, is a species of rocky habitats, nesting typically on cliff ledges and at the entrance to large caves. This habit would have brought them into close contact with cave-dwelling humans, a relationship usually linked to the development of dwellings in the Neolithic. We show that the association between humans and Rock Doves is an ancient one with its roots in the Palaeolithic and predates the arrival of modern humans into Europe. At Gorham's Cave, Gibraltar, the Neanderthals exploited Rock Doves for food for a period of over 40 thousand years, the earliest evidence dating to at least 67 thousand years ago. We show that the exploitation was not casual or sporadic, having found repeated evidence of the practice in different, widely spaced, temporal contexts within the cave. Our results point to hitherto unappreciated capacities of the Neanderthals to exploit birds as food resources on a regular basis. More so, they were practising it long before the arrival of modern humans and had therefore invented it independently. PMID:25101932

  3. The web of life: Natural science information on the Internet

    USGS Publications Warehouse

    Clement, Gail

    2000-01-01

    As society has come to equate economic prosperity with the health of our living resources, national science policy has called for the development of a comprehensive digital knowledge base to support informed decision making and wise resource management. The Internet and World Wide Web demonstrate the earliest stages of this evolving virtual library of the natural world, offering an increasing array of high-quality, innovative resources and services in the natural science arena. This article discusses the leading providers of natural science information on the Internet and highlights some of the exemplary resources they are delivering online. The discussion concludes with a brief discussion of the role of the librarian in developing the Web of natural science knowledge online and provides a short Webliography of starting points for further exploration of this subject area. PDF

  4. Using Plants to Explore the Nature & Structural Complexity of Life

    ERIC Educational Resources Information Center

    Howard, Ava R.

    2014-01-01

    Use of real specimens brings the study of biology to life. This activity brings easily acquired plant specimens into the classroom to tackle common alternative conceptions regarding life, size, complexity, the nature of science, and plants as multicellular organisms. The activity occurs after a discussion of the characteristics of life and engages…

  5. Ultraviolet selection pressure on the earliest organisms

    NASA Technical Reports Server (NTRS)

    Sagan, C.

    1973-01-01

    It had been proposed by Sagan (1957, 1961) that UV light, partially penetrating the primitive reducing atmosphere of the earth, posed a major problem for the earliest evolution of life. This argument is now updated and refined. The picture of a secondary reducing atmosphere is presented. It is assumed that an excess of hydrogen from this atmosphere has already escaped to space. The genetic material surrounded itself as a solution to the UV selection pressure with bases or nucleotides having no function whatever in replication or protein synthesis.

  6. The Purpose-Like Nature of Life

    NASA Astrophysics Data System (ADS)

    Radu, Popa

    According to Jeffrey Tze-Fei Wong (2002): A living system is one capable of reproduction and evolution, with a fundamental logic that demands an incessant search for performance with respect to its building blocks and arrangement of these building blocks. The search will end only when perfection or near perfection is reached. Without this built-in search, living systems could not have achieved the level of complexity and excellence to deserve the designation of life." The reader must understand that a distinction exists between how the common language defines purpose and what the theory of early life means by it. In Dexter's dictionary the word purpose' is anthropocentrically associated to performing an action with a conscious (deliberate) aim, intention and/or design. Yet life displays elaborate and suitable features that resemble the results of a purpose-like action (Szathmáry 2002). In fact any material-energetic order has the potential for a tendency' (or purposefulness') directed in the opposite sense to entropy (Valenzuela 2002). Because the purposefulness' of their function is such a vigorous and typical property of living organisms (Korzeniewski 2001, Szathmáry 2002), the search for a theory of life is more productive if it focuses on the best explanation for life (Bedau 1998).

  7. Earliest Life on Earth Preserved in Hotspring Deposits: Evidence from the 3.5 Ga Dresser Formation, Pilbara Craton, Australia, and Implications for the Search for Life on Mars

    NASA Astrophysics Data System (ADS)

    Van Kranendonk, M. J.; Djokic, T.; Campbell, K. A.; Walter, M. R.; Oto, T.; Nakamura, E.

    2016-05-01

    A variety of biosignatures preserved in hotspring facies from the c. 3.5 Ga Dresser Formation, Australia, lends support to an origin of life in terrestrial hotsprings, and have profound implications for the search for life on Mars.

  8. [Hans Jonas: Nature Conservation, Conservation of Life].

    PubMed

    Burgui Burgui, Mario

    2015-01-01

    This article discusses three of the problems that the German philosopher Hans Jonas studied. The first one addresses the need for a specific ethic dedicated to the moral dimension of environmental problems, from a different perspective to the traditional. The second problem is crucial in the discussion on environmental ethics: the value of the nature. Does the nature have an intrinsic value or an instrumental value only (to satisfy the interests of the human being)? The thesis of Jonas, which claimed that nature is a good in itself, were further elaborated here. And the third problem is the derivation of moral norms and the role of man in this ethic that recognizes a good in itself in nature. According to Jonas, the human being is not diminished by recognizing the intrinsic value of nature, since the man's uniqueness and value are unquestionable. From these three central issues, the paper highlights the importance of seeking the links between bioethics and environmental ethics to address the current environmental, social and economic crisis. PMID:26378598

  9. Natural disasters: forecasting economic and life losses

    USGS Publications Warehouse

    Nishenko, Stuart P.; Barton, Christopher C.

    1997-01-01

    Events such as hurricanes, earthquakes, floods, tsunamis, volcanic eruptions, and tornadoes are natural disasters because they negatively impact society, and so they must be measured and understood in human-related terms. At the U.S. Geological Survey, we have developed a new method to examine fatality and dollar-loss data, and to make probabilistic estimates of the frequency and magnitude of future events. This information is vital to large sectors of society including disaster relief agencies and insurance companies.

  10. The changing nature of life cycle assessment

    PubMed Central

    McManus, Marcelle C.; Taylor, Caroline M.

    2015-01-01

    LCA has evolved from its origins in energy analysis in the 1960s and 70s into a wide ranging tool used to determine impacts of products or systems over several environmental and resource issues. The approach has become more prevalent in research, industry and policy. Its use continues to expand as it seeks to encompass impacts as diverse as resource accounting and social well being. Carbon policy for bioenergy has driven many of these changes. Enabling assessment of complex issues over a life cycle basis is beneficial, but the process is sometimes difficult. LCA's use in framing is increasingly complex and more uncertain, and in some cases, irreconcilable. The charged environment surrounding biofuels and bioenergy exacerbates all of these. Reaching its full potential to help guide difficult policy discussions and emerging research involves successfully managing LCA's transition from attributional to consequential and from retrospective to prospective. This paper examines LCA's on-going evolution and its use within bioenergy deployment. The management of methodological growth in the context of the unique challenges associated with bioenergy and biofuels is explored. Changes seen in bioenergy LCA will bleed into other LCA arenas, especially where it is important that a sustainable solution is chosen. PMID:26664146

  11. Electron microscope methods in the search for the earliest life forms on Earth (in 3.5-3.3 GA cherts from the Barberton Greenstone Belt, South Africa): applications for extraterrestrial life studies

    NASA Astrophysics Data System (ADS)

    Westall, Frances; Gerneke, Dane

    1998-07-01

    A suite of previously unknown microfossils and related biogenic structures has been revealed in some of the oldest sediments on Earth using scanning electron microscopy. High resolution scanning electron microscopy of HF-etched, biolaminated charts has brought to light a variety of small fossil coccoid and rod-shaped bacteria and associated fossil biofilms containing bedding planes. These microfossils have ben completely replaced by minerals. This vastly improved early Archaean microfossil database sheds new light on the diversity of life on Earth relatively soon after the cessation of heavy bolide bombardment at about 3.8 Ga. This is the critical period when life may have been able to develop on Mars and these early Archaean terrestrial microfossils will serve as valuable analogues for possible extraterrestrial life.

  12. The earliest known sauropod dinosaur.

    PubMed

    Buffetaut, E; Suteethorn, V; Cuny, G; Tong, H; Le Loeuff, J; Khansubha, S; Jongautchariyakul, S

    2000-09-01

    Sauropods were a very successful group of dinosaurs during the Jurassic and Cretaceous periods, but their earlier history is poorly known. Until now, the earliest reported sauropod bones were from the Early Jurassic, and the only tentative evidence of earlier sauropods was in the form of controversial footprints. Here we report the discovery of an incomplete sauropod skeleton from the Late Triassic period of Thailand, which provides the first osteological evidence of pre-Jurassic sauropods. This dinosaur is markedly different from prosauropods and substantiates theoretical predictions that there was a fairly long period of sauropod evolution during the Triassic. PMID:10993074

  13. The earliest known holometabolous insects.

    PubMed

    Nel, André; Roques, Patrick; Nel, Patricia; Prokin, Alexander A; Bourgoin, Thierry; Prokop, Jakub; Szwedo, Jacek; Azar, Dany; Desutter-Grandcolas, Laure; Wappler, Torsten; Garrouste, Romain; Coty, David; Huang, Diying; Engel, Michael S; Kirejtshuk, Alexander G

    2013-11-14

    The Eumetabola (Endopterygota (also known as Holometabola) plus Paraneoptera) have the highest number of species of any clade, and greatly contribute to animal species biodiversity. The palaeoecological circumstances that favoured their emergence and success remain an intriguing question. Recent molecular phylogenetic analyses have suggested a wide range of dates for the initial appearance of the Holometabola, from the Middle Devonian epoch (391 million years (Myr) ago) to the Late Pennsylvanian epoch (311 Myr ago), and Hemiptera (310 Myr ago). Palaeoenvironments greatly changed over these periods, with global cooling and increasing complexity of green forests. The Pennsylvanian-period crown-eumetabolan fossil record remains notably incomplete, particularly as several fossils have been erroneously considered to be stem Holometabola (Supplementary Information); the earliest definitive beetles are from the start of the Permian period. The emergence of the hymenopterids, sister group to other Holometabola, is dated between 350 and 309 Myr ago, incongruent with their current earliest record (Middle Triassic epoch). Here we describe five fossils--a Gzhelian-age stem coleopterid, a holometabolous larva of uncertain ordinal affinity, a stem hymenopterid, and early Hemiptera and Psocodea, all from the Moscovian age--and reveal a notable penecontemporaneous breadth of early eumetabolan insects. These discoveries are more congruent with current hypotheses of clade divergence. Eumetabola experienced episodes of diversification during the Bashkirian-Moscovian and the Kasimovian-Gzhelian ages. This cladogenetic activity is perhaps related to notable episodes of drying resulting from glaciations, leading to the eventual demise in Euramerica of coal-swamp ecosystems, evidenced by floral turnover during this interval. These ancient species were of very small size, living in the shadow of Palaeozoic-era 'giant' insects. Although these discoveries reveal unexpected Pennsylvanian

  14. Oxygen requirements of the earliest animals

    PubMed Central

    Mills, Daniel B.; Ward, Lewis M.; Jones, CarriAyne; Sweeten, Brittany; Forth, Michael; Treusch, Alexander H.; Canfield, Donald E.

    2014-01-01

    A rise in the oxygen content of the atmosphere and oceans is one of the most popular explanations for the relatively late and abrupt appearance of animal life on Earth. In this scenario, Earth’s surface environment failed to meet the high oxygen requirements of animals up until the middle to late Neoproterozoic Era (850–542 million years ago), when oxygen concentrations sufficiently rose to permit the existence of animal life for the first time. Although multiple lines of geochemical evidence support an oxygenation of the Ediacaran oceans (635–542 million years ago), roughly corresponding with the first appearance of metazoans in the fossil record, the oxygen requirements of basal animals remain unclear. Here we show that modern demosponges, serving as analogs for early animals, can survive under low-oxygen conditions of 0.5–4.0% present atmospheric levels. Because the last common ancestor of metazoans likely exhibited a physiology and morphology similar to that of a modern sponge, its oxygen demands may have been met well before the enhanced oxygenation of the Ediacaran Period. Therefore, the origin of animals may not have been triggered by a contemporaneous rise in the oxygen content of the atmosphere and oceans. Instead, other ecological and developmental processes are needed to adequately explain the origin and earliest evolution of animal life on Earth. PMID:24550467

  15. Earliest recollections of childhood: a demographic analysis.

    PubMed

    Mullen, M K

    1994-07-01

    A theory has recently been advanced which proposes that the development autobiographical recollection is shaped by a child's participation in discussions of events with adults (e.g. Nelson, 1988; Snow, 1990). A logical prediction of the theory is that demographic factors related to the nature of linguistic environments might be associated with differences in the development of autobiographical recollection. Four questionnaire studies that test this prediction are presented. The results, on a total of 768 subjects, show that the age of earliest memory increases across birth order, is slightly earlier for females than for males, and is earlier for Caucasians than for Asians. These findings are discussed in light of previous research showing that parents interact and talk more with first-borns and with girls, and in light of differences between Western and Asian cultures in socialization goals and the significance of autobiography in the development of self-concept. PMID:7924199

  16. On the electro-magnetic nature of life.

    PubMed

    Jacobson, J I

    1989-01-01

    Man has wondered since the dawning of thought about the origin and the meaning of the spark of life. How does life work and what is the difference between life and non-life? This paper wonders about the part that electromagnetism plays in the life process. It proposes a new insight into the relation of in vivo electromagnetic fields and gravitational fields and discusses such manifestations as solitons, the quantum hall effect, gravity waves, biological strings, biologically closed electric circuits, phonos and the piezoelectric nature of living tissue. It proposes a new and fundamental form of resonance, called Jacobson resonance. The system unifies quantum genetic characters and associated structures with electromagnetic field interaction energies. The result is the reorientation of atomic crystal lattice structures of organic molecules critical to the sustenance of life. A new treatment methodology is proposed for genomic, viral and trophic factor disorders essentially in terms of the potential efficacy of the magnetic force to reorient the spin angular momenta of electrons and protons; to therein rearrange atomic and molecular magnetic domains regulating homeostasis on microscopic, mesosopic and macroscopic levels through biological amplification of quantum interactions. Finally it proposes that the equation, mc2 = Bvl coulomb, may indeed represent the achievement of fourfold physical unification, the unification of physics and medicine, and resultant production of a thorough understanding of what may be the most fundamental natural law of the universe representing the ultimate goal of Einsteinian equivalence and relativistic field theory. PMID:2633105

  17. Life-cycle analysis of shale gas and natural gas.

    SciTech Connect

    Clark, C.E.; Han, J.; Burnham, A.; Dunn, J.B.; Wang, M.

    2012-01-27

    The technologies and practices that have enabled the recent boom in shale gas production have also brought attention to the environmental impacts of its use. Using the current state of knowledge of the recovery, processing, and distribution of shale gas and conventional natural gas, we have estimated up-to-date, life-cycle greenhouse gas emissions. In addition, we have developed distribution functions for key parameters in each pathway to examine uncertainty and identify data gaps - such as methane emissions from shale gas well completions and conventional natural gas liquid unloadings - that need to be addressed further. Our base case results show that shale gas life-cycle emissions are 6% lower than those of conventional natural gas. However, the range in values for shale and conventional gas overlap, so there is a statistical uncertainty regarding whether shale gas emissions are indeed lower than conventional gas emissions. This life-cycle analysis provides insight into the critical stages in the natural gas industry where emissions occur and where opportunities exist to reduce the greenhouse gas footprint of natural gas.

  18. The Origin and Earliest History of the Earth

    NASA Astrophysics Data System (ADS)

    Halliday, A. N.

    2003-12-01

    treatment here. Furthermore, there are major gaps in our knowledge that render a comprehensive overview unworkable. The nature of the early crust (item (vii)) is poorly constrained, although some lines of evidence will be mentioned. The nature of the earliest life forms (item (viii)) is so loaded with projections into underconstrained hypothetical environments that not a great deal can be described as providing a factual basis suitable for inclusion in a reference volume at this time. Even in those areas in which geochemical constraints are more plentiful, it is essential to integrate them with astronomical observations and dynamic (physical) models of planetary growth and primary differentiation. In some cases, the various theoretical dynamic models can be tested with isotopic and geochemical methods. In other cases, it is the Earth's composition itself that has been used to erect specific accretion paradigms. Therefore, much of this background is provided in this chapter.All these models and interpretations of geochemical data involve some level of assumption in scaling the results to the big picture of the Earth. Without this, one cannot erect useful concepts that address the above issues. It is one of the main goals of this chapter to explain what these underlying assumptions are. As a consequence, this chapter focuses on the range of interpretations and uncertainties, leaving many issues "open." The chapter finishes by indicating where the main sources of uncertainty remain and what might be done about these in the future.

  19. 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

  20. Theory of the origin, evolution, and nature of life.

    PubMed

    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

  1. Sustainable Life Cycles of Natural-Precursor-Derived Nanocarbons.

    PubMed

    Bazaka, Kateryna; Jacob, Mohan V; Ostrikov, Kostya Ken

    2016-01-13

    Sustainable societal and economic development relies on novel nanotechnologies that offer maximum efficiency at minimal environmental cost. Yet, it is very challenging to apply green chemistry approaches across the entire life cycle of nanotech products, from design and nanomaterial synthesis to utilization and disposal. Recently, novel, efficient methods based on nonequilibrium reactive plasma chemistries that minimize the process steps and dramatically reduce the use of expensive and hazardous reagents have been applied to low-cost natural and waste sources to produce value-added nanomaterials with a wide range of applications. This review discusses the distinctive effects of nonequilibrium reactive chemistries and how these effects can aid and advance the integration of sustainable chemistry into each stage of nanotech product life. Examples of the use of enabling plasma-based technologies in sustainable production and degradation of nanotech products are discussed-from selection of precursors derived from natural resources and their conversion into functional building units, to methods for green synthesis of useful naturally degradable carbon-based nanomaterials, to device operation and eventual disintegration into naturally degradable yet potentially reusable byproducts. PMID:26717047

  2. Natural selection drives the evolution of ant life cycles

    PubMed Central

    Wilson, Edward O.; Nowak, Martin A.

    2014-01-01

    The genetic origin of advanced social organization has long been one of the outstanding problems of evolutionary biology. Here we present an analysis of the major steps in ant evolution, based for the first time, to our knowledge, on combined recent advances in paleontology, phylogeny, and the study of contemporary life histories. We provide evidence of the causal forces of natural selection shaping several key phenomena: (i) the relative lateness and rarity in geological time of the emergence of eusociality in ants and other animal phylads; (ii) the prevalence of monogamy at the time of evolutionary origin; and (iii) the female-biased sex allocation observed in many ant species. We argue that a clear understanding of the evolution of social insects can emerge if, in addition to relatedness-based arguments, we take into account key factors of natural history and study how natural selection acts on alleles that modify social behavior. PMID:25114217

  3. Fieldwork: man in the system of nature and priority of natural laws in human life.

    PubMed

    Tinyakova, Elena

    2007-06-01

    Fieldwork is a branch of inseparable unity of natural and humanitarian sciences; it is aimed at the cultural origin of humanity on the maximum level of its variety. Practically all natural sciences have some space determined by ethnic conscience in nature cognition: ethnodemography, ethnobotany, ethnozoology, etc. Fieldwork guides the research of human culture from the laws of nature. This kind of knowledge is useful to balance human relations with nature and avoid conflicts. Peoples should exchange their wisdom in the dialogue with nature to be more safe. Fieldwork understood as traditional culture only, explaining the variety of ethnoses on our earth, is just the narrow and diachronic level of this branch of knowledge. The cosmological knowledge, where fantasy and not exhausted in its cognition understanding the world of nature are mixed, forms the source of fieldwork and in many respects explains the direction of knowledge: the man finds himself under the open sky, he is the child of nature. Then as time went on there appeared a gradual transition--first nature was creating the man, then by and by he began turning to answer nature by his activity. Nowadays the man is actively creating nature. There are two levels of fieldwork: the ancient one which deals with the origin of ethnoses and the modern one which explores how contemporary life is determined by ethnic specific traits. Fieldwork is the core of multidisciplinary situation in man's knowledge. It is related to such humanitarian sciences: semiotics, culturology, sociology, history, philosophy, literature, linguistics. In the cycle of natural sciences fieldwork stands close to anthropology, geography, biology, demography. Fieldwork as a science has the two main levels--the "sophy" level and the logos "level". The first one discovers wisdom of human life, the second one is aimed at logical structuring of knowledge, here proceed various classifications of peoples. PMID:17847946

  4. Earth’s Earliest Atmospheres

    PubMed Central

    Zahnle, Kevin; Schaefer, Laura; Fegley, Bruce

    2010-01-01

    Earth is the one known example of an inhabited planet and to current knowledge the likeliest site of the one known origin of life. Here we discuss the origin of Earth’s atmosphere and ocean and some of the environmental conditions of the early Earth as they may relate to the origin of life. A key punctuating event in the narrative is the Moon-forming impact, partly because it made Earth for a short time absolutely uninhabitable, and partly because it sets the boundary conditions for Earth’s subsequent evolution. If life began on Earth, as opposed to having migrated here, it would have done so after the Moon-forming impact. What took place before the Moon formed determined the bulk properties of the Earth and probably determined the overall compositions and sizes of its atmospheres and oceans. What took place afterward animated these materials. One interesting consequence of the Moon-forming impact is that the mantle is devolatized, so that the volatiles subsequently fell out in a kind of condensation sequence. This ensures that the volatiles were concentrated toward the surface so that, for example, the oceans were likely salty from the start. We also point out that an atmosphere generated by impact degassing would tend to have a composition reflective of the impacting bodies (rather than the mantle), and these are almost without exception strongly reducing and volatile-rich. A consequence is that, although CO- or methane-rich atmospheres are not necessarily stable as steady states, they are quite likely to have existed as long-lived transients, many times. With CO comes abundant chemical energy in a metastable package, and with methane comes hydrogen cyanide and ammonia as important albeit less abundant gases. PMID:20573713

  5. Adults’ reports of their earliest memories: Consistency in events, ages, and narrative characteristics over time

    PubMed Central

    Bauer, Patricia J.; Tasdemir-Ozdes, Aylin; Larkina, Marina

    2014-01-01

    Earliest memories have been of interest since the late 1800s, when it was first noted that most adults do not have memories from the first years of life (so-called childhood amnesia). Several characteristics of adults’ earliest memories have been investigated, including emotional content, the perspective from which they are recalled, and vividness. The focus of the present research was a feature of early memories heretofore relatively neglected in the literature, namely, their consistency. Adults reported their earliest memories 2 to 4 times over a 4-year period. Reports of earliest memories were highly consistent in the events identified as the bases for earliest memories, the reported age at the time of the event, and in terms of qualities of the narrative descriptions. These findings imply stability in the boundary that marks the offset of childhood amnesia, as well as in the beginning of a continuous sense of self over time. PMID:24836979

  6. Adults' reports of their earliest memories: consistency in events, ages, and narrative characteristics over time.

    PubMed

    Bauer, Patricia J; Tasdemir-Ozdes, Aylin; Larkina, Marina

    2014-07-01

    Earliest memories have been of interest since the late 1800s, when it was first noted that most adults do not have memories from the first years of life (so-called childhood amnesia). Several characteristics of adults' earliest memories have been investigated, including emotional content, the perspective from which they are recalled, and vividness. The focus of the present research was a feature of early memories heretofore relatively neglected in the literature, namely, their consistency. Adults reported their earliest memories 2-4 times over a 4-year period. Reports of earliest memories were highly consistent in the events identified as the bases for earliest memories, the reported age at the time of the event, and in terms of qualities of the narrative descriptions. These findings imply stability in the boundary that marks the offset of childhood amnesia, as well as in the beginning of a continuous sense of self over time. PMID:24836979

  7. Convergent evolution as natural experiment: the tape of life reconsidered.

    PubMed

    Powell, Russell; Mariscal, Carlos

    2015-12-01

    Stephen Jay Gould argued that replaying the 'tape of life' would result in radically different evolutionary outcomes. Recently, biologists and philosophers of science have paid increasing attention to the theoretical importance of convergent evolution-the independent origination of similar biological forms and functions-which many interpret as evidence against Gould's thesis. In this paper, we examine the evidentiary relevance of convergent evolution for the radical contingency debate. We show that under the right conditions, episodes of convergent evolution can constitute valid natural experiments that support inferences regarding the deep counterfactual stability of macroevolutionary outcomes. However, we argue that proponents of convergence have problematically lumped causally heterogeneous phenomena into a single evidentiary basket, in effect treating all convergent events as if they are of equivalent theoretical import. As a result, the 'critique from convergent evolution' fails to engage with key claims of the radical contingency thesis. To remedy this, we develop ways to break down the heterogeneous set of convergent events based on the nature of the generalizations they support. Adopting this more nuanced approach to convergent evolution allows us to differentiate iterated evolutionary outcomes that are probably common among alternative evolutionary histories and subject to law-like generalizations, from those that do little to undermine and may even support, the Gouldian view of life. PMID:26640647

  8. Diet and the evolution of the earliest human ancestors.

    PubMed

    Teaford, M F; Ungar, P S

    2000-12-01

    Over the past decade, discussions of the evolution of the earliest human ancestors have focused on the locomotion of the australopithecines. Recent discoveries in a broad range of disciplines have raised important questions about the influence of ecological factors in early human evolution. Here we trace the cranial and dental traits of the early australopithecines through time, to show that between 4.4 million and 2.3 million years ago, the dietary capabilities of the earliest hominids changed dramatically, leaving them well suited for life in a variety of habitats and able to cope with significant changes in resource availability associated with long-term and short-term climatic fluctuations. PMID:11095758

  9. Diet and the evolution of the earliest human ancestors

    PubMed Central

    Teaford, Mark F.; Ungar, Peter S.

    2000-01-01

    Over the past decade, discussions of the evolution of the earliest human ancestors have focused on the locomotion of the australopithecines. Recent discoveries in a broad range of disciplines have raised important questions about the influence of ecological factors in early human evolution. Here we trace the cranial and dental traits of the early australopithecines through time, to show that between 4.4 million and 2.3 million years ago, the dietary capabilities of the earliest hominids changed dramatically, leaving them well suited for life in a variety of habitats and able to cope with significant changes in resource availability associated with long-term and short-term climatic fluctuations. PMID:11095758

  10. Age of the earliest african anthropoids.

    PubMed

    Fleagle, J G; Bown, T M; Obradovich, J D; Simons, E L

    1986-12-01

    The earliest fossil record of African anthropoid primates (monkeys and apes) comes from the Jebel Qatrani Formation in the Fayum depression of Egypt. Reevaluation of both geologic and faunal evidence indicates that this formation was deposited in the early part of the Oligocene Epoch, more than 31 million years ago, earlier than previous estimates. The great antiquity of the fossil higher primates from Egypt accords well with their primitive morphology compared with later Old World higher primates. Thus, the anthropoid primates and hystricomorph rodents from Fayum are also considerably older than the earliest higher primates and rodents from South America. PMID:17778006

  11. Phylogenomics supports microsporidia as the earliest diverging clade of sequenced fungi

    PubMed Central

    2012-01-01

    Background Microsporidia is one of the taxa that have experienced the most dramatic taxonomic reclassifications. Once thought to be among the earliest diverging eukaryotes, the fungal nature of this group of intracellular pathogens is now widely accepted. However, the specific position of microsporidia within the fungal tree of life is still debated. Due to the presence of accelerated evolutionary rates, phylogenetic analyses involving microsporidia are prone to methodological artifacts, such as long-branch attraction, especially when taxon sampling is limited. Results Here we exploit the recent availability of six complete microsporidian genomes to re-assess the long-standing question of their phylogenetic position. We show that microsporidians have a similar low level of conservation of gene neighborhood with other groups of fungi when controlling for the confounding effects of recent segmental duplications. A combined analysis of thousands of gene trees supports a topology in which microsporidia is a sister group to all other sequenced fungi. Moreover, this topology received increased support when less informative trees were discarded. This position of microsporidia was also strongly supported based on the combined analysis of 53 concatenated genes, and was robust to filters controlling for rate heterogeneity, compositional bias, long branch attraction and heterotachy. Conclusions Altogether, our data strongly support a scenario in which microsporidia is the earliest-diverging clade of sequenced fungi. PMID:22651672

  12. Earliest Recollections of Childhood: A Demographic Analysis.

    ERIC Educational Resources Information Center

    Mullen, Mary K.

    1994-01-01

    Four questionnaires examined the association of demographic factors with recollection for 768 adults. Found that the age of earliest memory increased across birth order, was slightly earlier for females than for males, and was earlier for Caucasians than for Asians. (Author/BC)

  13. The earliest record of human activity in northern Europe.

    PubMed

    Parfitt, Simon A; Barendregt, René W; Breda, Marzia; Candy, Ian; Collins, Matthew J; Coope, G Russell; Durbidge, Paul; Field, Mike H; Lee, Jonathan R; Lister, Adrian M; Mutch, Robert; Penkman, Kirsty E H; Preece, Richard C; Rose, James; Stringer, Christopher B; Symmons, Robert; Whittaker, John E; Wymer, John J; Stuart, Anthony J

    2005-12-15

    The colonization of Eurasia by early humans is a key event after their spread out of Africa, but the nature, timing and ecological context of the earliest human occupation of northwest Europe is uncertain and has been the subject of intense debate. The southern Caucasus was occupied about 1.8 million years (Myr) ago, whereas human remains from Atapuerca-TD6, Spain (more than 780 kyr ago) and Ceprano, Italy (about 800 kyr ago) show that early Homo had dispersed to the Mediterranean hinterland before the Brunhes-Matuyama magnetic polarity reversal (780 kyr ago). Until now, the earliest uncontested artefacts from northern Europe were much younger, suggesting that humans were unable to colonize northern latitudes until about 500 kyr ago. Here we report flint artefacts from the Cromer Forest-bed Formation at Pakefield (52 degrees N), Suffolk, UK, from an interglacial sequence yielding a diverse range of plant and animal fossils. Event and lithostratigraphy, palaeomagnetism, amino acid geochronology and biostratigraphy indicate that the artefacts date to the early part of the Brunhes Chron (about 700 kyr ago) and thus represent the earliest unequivocal evidence for human presence north of the Alps. PMID:16355223

  14. Examining the Factor Structure and Hierarchical Nature of the Quality of Life Construct

    ERIC Educational Resources Information Center

    Wang, Mian; Schalock, Robert L.; Verdugo, Miguel A.; Jenaro, Christina

    2010-01-01

    There is considerable debate in the area of individual quality of life research regarding the factor structure and hierarchical nature of the quality of life construct. Our purpose in this study was to test via structural equation modeling an a priori quality of life model consisting of eight first-order factors and one second-order factor. Data…

  15. Controlled Ecological Life Support Systems: Natural and Artificial Ecosystems

    NASA Technical Reports Server (NTRS)

    Macelroy, Robert D. (Editor); Thompson, Brad G. (Editor); Tibbitts, Theodore W. (Editor); Volk, Tyler (Editor)

    1989-01-01

    The scientists supported by the NASA sponsored Controlled Ecological Life Support Systems (CELSS) program have played a major role in creating a Committee on Space Research (COSPAR) section devoted to the development of bioregenerative life support for use in space. The series of 22 papers were sponsored by Subcommission F.4. The papers deal with many of the diverse aspects of life support, and with outgrowth technologies that may have commercial applications in fields such as biotechnology and bioengineering. Papers from researchers in France, Canada, Japan and the USSR are also presented.

  16. Considerations on Terrestrial Iron Depositing Analogs to Earliest Mars

    NASA Technical Reports Server (NTRS)

    Brown, Igor I.; Allen, Carlton C.; Sarkisova, S. A.; Garrison, D. H.; McKay, D. S.

    2007-01-01

    Iron oxide and hydroxide minerals, including hematite, can mineralize and preservemicrofossils and physical biomarkers (Allen at al., 2004). Preserved remnants of phototrophic microorganisms are recognized as biosignatures of past life on Earth (Schopf, 2006). To date, two types of surface iron depositing environments have been studied as analogs to possible habitable environments on earliest Mars: the highly acidified Rio Tinto River (Iberian Belt, Spain) [Gomez Ortis et al., 2007], and the nearneutral iron depositing Chocolate Pots Hot Spring (Yellowstone National Park, US) [Parenteau at al., 2005]. While phototrophs in the Rio Tinto are only represented by eukaryotic algae (Amaral Zettler et all., 2002), Chocolate Pots is mainly populated with cyanobacteria (Pierson et all., 2000; Brown et all., 2007). Which of these environments is the closer analog to a potentially habitable early Mars? Paleobiological data, combined with recent "tree of life" interpretations, suggest that phototrophic eukaryotes evolved not earlier than 2.5 - 2.8 b.y. after Earth s accretion (4.6 b.y.), while cyanobacteria and /or their iron-tolerant predecessors evolved between 1 - 1.5 b.y. after accretion (Brown et al., 2007). Lindsay and Brasier (2002) postulated that microbial life on Mars surface could have lasted no more than 1-1.5 b.y. after Mars accretion (also 4.6 b.y.). Recent multispectral mapping of Mars suggests that near-neutral wet environments prevailed at approximately this time (Bibring, et al., 2006). Thus, near-neutral iron depositing hot springs such as Chocolate Pots Hot Spring seem to be the more likely habitable analogs for earliest Mars.

  17. The earliest published electrocardiogram showing ventricular preexcitation.

    PubMed

    Von Knorre, Georg H

    2005-03-01

    When in 1930, Wolff, Parkinson, and White published what is today known as the WPW, or preexcitation syndrome, they, and subsequently others, found few comparable cases in the preceding literature. Among these the report of Cohn and Fraser, published in 1913, was the earliest. However, another even earlier documentation in a 1909 article by Hoffmann escaped notice till now. The ECG of a patient with paroxysmal tachycardia reveals a short PR interval and a delta-wave-induced widening of the QRS complex, even though the reproduced tachycardia was not preexcitation related. The interpretation of this poorly reproduced ECG can be confirmed by another and more detailed description of the patient in an electrocardiography textbook published in 1914 by the same author. Thus, the earliest publication of an ECG showing ventricular preexcitation now can be dated back to 1909. Moreover, the Hoffmann monograph contains two additional examples of the WPW syndrome not noticed until now. All three cases published by Hoffmann had their first ECG recordings in 1912 or earlier. PMID:15733183

  18. The Tuareg: Nature Changes a Life Style. Mini-Module.

    ERIC Educational Resources Information Center

    African-American Inst., New York, NY. School Services Div.

    This module contains a description of the Tuareg society in Africa, a list of resources for teachers and students to learn how the African drought is affecting Tuareg life-style, and a lesson plan with eight questions for class discussion. The social strata are described within the Tuareg, ranging from nomadic herd-tending nobles to servants who…

  19. The Dynamic Nature of Genomes across the Tree of Life

    PubMed Central

    Oliverio, Angela M.; Katz, Laura A.

    2014-01-01

    Genomes are dynamic in lineages across the tree of life. Among bacteria and archaea, for example, DNA content varies throughout life cycles, and nonbinary cell division in diverse lineages indicates the need for coordination of the inheritance of genomes. These observations contrast with the textbook view that bacterial and archaeal genomes are monoploid (i.e., single copied) and fixed both within species and throughout an individual’s lifetime. Here, we synthesize information on three aspects of dynamic genomes from exemplars representing a diverse array of bacterial and archaeal lineages: 1) ploidy level variation, 2) epigenetic mechanisms, and 3) life cycle variation. For example, the Euryarchaeota analyzed to date are all polyploid, as is the bacterium Epulopiscium that contains up to tens of thousands of copies of its genome and reproduces by viviparity. The bacterium Deinococcus radiodurans and the archaeon Halobacterium sp. NRC-1 can repair a highly fragmented genome within a few hours. Moreover, bacterial genera such as Dermocarpella and Planctomyces reproduce by fission (i.e., generating many cells from one cell) and budding, respectively, highlighting the need for regulation of genome inheritance in these lineages. Combining these data with our previous work on widespread genome dynamics among eukaryotes, we hypothesize that dynamic genomes are a rule rather than the exception across the tree of life. Further, we speculate that all domains may have the ability to distinguish germline from somatic DNA and that this ability may have been present the last universal common ancestor. PMID:24500971

  20. The dynamic nature of genomes across the tree of life.

    PubMed

    Oliverio, Angela M; Katz, Laura A

    2014-03-01

    Genomes are dynamic in lineages across the tree of life. Among bacteria and archaea, for example, DNA content varies throughout life cycles, and nonbinary cell division in diverse lineages indicates the need for coordination of the inheritance of genomes. These observations contrast with the textbook view that bacterial and archaeal genomes are monoploid (i.e., single copied) and fixed both within species and throughout an individual's lifetime. Here, we synthesize information on three aspects of dynamic genomes from exemplars representing a diverse array of bacterial and archaeal lineages: 1) ploidy level variation, 2) epigenetic mechanisms, and 3) life cycle variation. For example, the Euryarchaeota analyzed to date are all polyploid, as is the bacterium Epulopiscium that contains up to tens of thousands of copies of its genome and reproduces by viviparity. The bacterium Deinococcus radiodurans and the archaeon Halobacterium sp. NRC-1 can repair a highly fragmented genome within a few hours. Moreover, bacterial genera such as Dermocarpella and Planctomyces reproduce by fission (i.e., generating many cells from one cell) and budding, respectively, highlighting the need for regulation of genome inheritance in these lineages. Combining these data with our previous work on widespread genome dynamics among eukaryotes, we hypothesize that dynamic genomes are a rule rather than the exception across the tree of life. Further, we speculate that all domains may have the ability to distinguish germline from somatic DNA and that this ability may have been present the last universal common ancestor. PMID:24500971

  1. The earliest known case of a lithopaedion.

    PubMed Central

    Bondeson, J

    1996-01-01

    A lithopaedion, or stone-child, is a dead fetus, usually the result of a primary or secondary abdominal pregnancy, that has been retained by the mother and subsequently calcified. This paper describes the earliest known case of this phenomenon. It was discovered in 1582, at the autopsy of a 68-year-old woman in the French city of Sens, and described in a thesis by the physician Jean d'Ailleboust. The woman had carried her lithopaedion for 28 years. In this historical vignette, the lithopaedion of Sens is compared to later instances of this phenomenon. The ultimate fate of the lithopaedion specimen, which was widely traded throughout Europe in the 1600s before finally ending up in Copenhagen, is traced. PMID:8709075

  2. Earliest known crown-group salamanders.

    PubMed

    Gao, Ke-Qin; Shubin, Neil H

    2003-03-27

    Salamanders are a model system for studying the rates and patterns of the evolution of new anatomical structures. Recent discoveries of abundant Late Jurassic and Early Cretaceous salamanders are helping to address these issues. Here we report the discovery of well-preserved Middle Jurassic salamanders from China, which constitutes the earliest known record of crown-group urodeles (living salamanders and their closest relatives). The new specimens are from the volcanic deposits of the Jiulongshan Formation (Bathonian), Inner Mongolia, China, and represent basal members of the Cryptobranchidae, a family that includes the endangered Asian giant salamander (Andrias) and the North American hellbender (Cryptobranchus). These fossils document a Mesozoic record of the Cryptobranchidae, predating the previous record of the group by some 100 million years. This discovery provides evidence to support the hypothesis that the divergence of the Cryptobranchidae from the Hynobiidae had taken place in Asia before the Middle Jurassic period. PMID:12660782

  3. Reuniting Art and Nature in the Life of the Child

    ERIC Educational Resources Information Center

    Strauch-Nelson, Wendy

    2012-01-01

    Sometimes looking at the history of education can be a bit frustrating. Examination of the past is necessary, however, if people are to move forward responsibly for the sake of the child. In this article, the author examines the common ancestry of the kindergarten, art, and nature study. As the founder of the kindergarten, Friedrich Froebel played…

  4. 43 CFR 15.2 - Removal or destruction of natural features and marine life.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... LARGO CORAL REEF PRESERVE § 15.2 Removal or destruction of natural features and marine life. No person... this Preserve. No rope, wire or other contrivance shall be attached to any coral, rock or...

  5. 43 CFR 15.2 - Removal or destruction of natural features and marine life.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... LARGO CORAL REEF PRESERVE § 15.2 Removal or destruction of natural features and marine life. No person... this Preserve. No rope, wire or other contrivance shall be attached to any coral, rock or...

  6. 43 CFR 15.2 - Removal or destruction of natural features and marine life.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... LARGO CORAL REEF PRESERVE § 15.2 Removal or destruction of natural features and marine life. No person... this Preserve. No rope, wire or other contrivance shall be attached to any coral, rock or...

  7. 43 CFR 15.2 - Removal or destruction of natural features and marine life.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... LARGO CORAL REEF PRESERVE § 15.2 Removal or destruction of natural features and marine life. No person... this Preserve. No rope, wire or other contrivance shall be attached to any coral, rock or...

  8. 43 CFR 15.2 - Removal or destruction of natural features and marine life.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Removal or destruction of natural features and marine life. 15.2 Section 15.2 Public Lands: Interior Office of the Secretary of the Interior KEY LARGO CORAL REEF PRESERVE § 15.2 Removal or destruction of natural features and marine life. No person shall destroy, injure, deface, mar,...

  9. Learning Evolution and the Nature of Science Using Evolutionary Computing and Artificial Life

    ERIC Educational Resources Information Center

    Pennock, Robert T.

    2007-01-01

    Because evolution in natural systems happens so slowly, it is difficult to design inquiry-based labs where students can experiment and observe evolution in the way they can when studying other phenomena. New research in evolutionary computation and artificial life provides a solution to this problem. This paper describes a new A-Life software…

  10. The Earliest Ion Channels in Protocellular Membranes

    NASA Technical Reports Server (NTRS)

    Mijajlovic, Milan; Pohorille, Andrew; Wilson, Michael; Wei, Chenyu

    2010-01-01

    Cellular membranes with their hydrophobic interior are virtually impermeable to ions. Bulk of ion transport through them is enabled through ion channels. Ion channels of contemporary cells are complex protein molecules which span the membrane creating a cylindrical pore filled with water. Protocells, which are widely regarded as precursors to modern cells, had similarly impermeable membranes, but the set of proteins in their disposal was much simpler and more limited. We have been, therefore, exploring an idea that the first ion channels in protocellular membranes were formed by much smaller peptide molecules that could spontaneously selfassemble into short-lived cylindrical bundles in a membrane. Earlier studies have shown that a group of peptides known as peptaibols is capable of forming ion channels in lipid bilayers when they are exposed to an electric field. Peptaibols are small, non-genetically encoded peptides produced by some fungi as a part of their system of defense against bacteria. They are usually only 14-20 residues long, which is just enough to span the membrane. Their sequence is characterized by the presence of non-standard amino acids which, interestingly, are also expected to have existed on the early earth. In particular, the presence of 2-aminoisobutyric acid (AIB) gives peptaibols strong helix forming propensities. Association of the helices inside membranes leads to the formation of cylindrical bundles, typically containing 4 to 10 monomers. Although peptaibols are excellent candidates for models of the earliest ion channels their structures, which are stabilized only by van der Waals forces and occasional hydrogen bonds between neighboring helices, are not very stable. Although it might properly reflect protobiological reality, it is also a major obstacle in studying channel behavior. For this reason we focused on two members of the peptaibol family, trichotoxin and antiamoebin, which are characterized by a single conductance level. This

  11. The earliest ion channels in protocellular membranes

    NASA Astrophysics Data System (ADS)

    Mijajlovic, Milan; Pohorille, Andrew; Wilson, Michael; Wei, Chenyu

    Cellular membranes with their hydrophobic interior are virtually impermeable to ions. Bulk of ion transport through them is enabled through ion channels. Ion channels of contemporary cells are complex protein molecules which span the membrane creating a cylindrical pore filled with water. Protocells, which are widely regarded as precursors to modern cells, had similarly impermeable membranes, but the set of proteins in their disposal was much simpler and more limited. We have been, therefore, exploring an idea that the first ion channels in protocellular membranes were formed by much smaller peptide molecules that could spontaneously self-assemble into short-lived cylindrical bundles in a membrane. Earlier studies have shown that a group of peptides known as peptaibols is capable of forming ion channels in lipid bilayers when they are exposed to an electric field. Peptaibols are small, non-genetically encoded peptides produced by some fungi as a part of their system of defense against bacteria. They are usually only 14-20 residues long, which is just enough to span the membrane. Their sequence is characterized by the presence of non-standard amino acids which, interestingly, are also expected to have existed on the early earth. In particular, the presence of 2-aminoisobutyric acid (AIB) gives peptaibols strong helix forming propensities. Association of the helices inside membranes leads to the formation of cylindrical bundles, typically containing 4 to 10 monomers. Although peptaibols are excellent candidates for models of the earliest ion channels their struc-tures, which are stabilized only by van der Waals forces and occasional hydrogen bonds between neighboring helices, are not very stable. Although it might properly reflect protobiological real-ity, it is also a major obstacle in studying channel behavior. For this reason we focused on two members of the peptaibol family, trichotoxin and antiamoebin, which are characterized by a single conductance level. This

  12. Life Cycle GHG Emissions from Conventional Natural Gas Power Generation: Systematic Review and Harmonization (Presentation)

    SciTech Connect

    Heath, G.; O'Donoughue, P.; Whitaker, M.

    2012-12-01

    This research provides a systematic review and harmonization of the life cycle assessment (LCA) literature of electricity generated from conventionally produced natural gas. We focus on estimates of greenhouse gases (GHGs) emitted in the life cycle of electricity generation from conventionally produced natural gas in combustion turbines (NGCT) and combined-cycle (NGCC) systems. A process we term "harmonization" was employed to align several common system performance parameters and assumptions to better allow for cross-study comparisons, with the goal of clarifying central tendency and reducing variability in estimates of life cycle GHG emissions. This presentation summarizes preliminary results.

  13. Nature over nurture: temperament, personality, and life span development.

    PubMed

    McCrae, R R; Costa, P T; Ostendorf, F; Angleitner, A; Hrebícková, M; Avia, M D; Sanz, J; Sánchez-Bernardos, M L; Kusdil, M E; Woodfield, R; Saunders, P R; Smith, P B

    2000-01-01

    Temperaments are often regarded as biologically based psychological tendencies with intrinsic paths of development. It is argued that this definition applies to the personality traits of the five-factor model. Evidence for the endogenous nature of traits is summarized from studies of behavior genetics, parent-child relations, personality structure, animal personality, and the longitudinal stability of individual differences. New evidence for intrinsic maturation is offered from analyses of NEO Five-Factor Inventory scores for men and women age 14 and over in German, British, Spanish, Czech, and Turkish samples (N = 5,085). These data support strong conceptual links to child temperament despite modest empirical associations. The intrinsic maturation of personality is complemented by the culturally conditioned development of characteristic adaptations that express personality; interventions in human development are best addressed to these. PMID:10653513

  14. Earliest archaeological evidence of persistent hominin carnivory.

    PubMed

    Ferraro, Joseph V; Plummer, Thomas W; Pobiner, Briana L; Oliver, James S; Bishop, Laura C; Braun, David R; Ditchfield, Peter W; Seaman, John W; Binetti, Katie M; Seaman, John W; Hertel, Fritz; Potts, Richard

    2013-01-01

    The emergence of lithic technology by ≈ 2.6 million years ago (Ma) is often interpreted as a correlate of increasingly recurrent hominin acquisition and consumption of animal remains. Associated faunal evidence, however, is poorly preserved prior to ≈ 1.8 Ma, limiting our understanding of early archaeological (Oldowan) hominin carnivory. Here, we detail three large well-preserved zooarchaeological assemblages from Kanjera South, Kenya. The assemblages date to 2.0 Ma, pre-dating all previously published archaeofaunas of appreciable size. At Kanjera, there is clear evidence that Oldowan hominins acquired and processed numerous, relatively complete, small ungulate carcasses. Moreover, they had at least occasional access to the fleshed remains of larger, wildebeest-sized animals. The overall record of hominin activities is consistent through the stratified sequence - spanning hundreds to thousands of years - and provides the earliest archaeological evidence of sustained hominin involvement with fleshed animal remains (i.e., persistent carnivory), a foraging adaptation central to many models of hominin evolution. PMID:23637995

  15. Earliest Archaeological Evidence of Persistent Hominin Carnivory

    PubMed Central

    Ferraro, Joseph V.; Plummer, Thomas W.; Pobiner, Briana L.; Oliver, James S.; Bishop, Laura C.; Braun, David R.; Ditchfield, Peter W.; Seaman, John W.; Binetti, Katie M.; Seaman, John W.; Hertel, Fritz; Potts, Richard

    2013-01-01

    The emergence of lithic technology by ∼2.6 million years ago (Ma) is often interpreted as a correlate of increasingly recurrent hominin acquisition and consumption of animal remains. Associated faunal evidence, however, is poorly preserved prior to ∼1.8 Ma, limiting our understanding of early archaeological (Oldowan) hominin carnivory. Here, we detail three large well-preserved zooarchaeological assemblages from Kanjera South, Kenya. The assemblages date to ∼2.0 Ma, pre-dating all previously published archaeofaunas of appreciable size. At Kanjera, there is clear evidence that Oldowan hominins acquired and processed numerous, relatively complete, small ungulate carcasses. Moreover, they had at least occasional access to the fleshed remains of larger, wildebeest-sized animals. The overall record of hominin activities is consistent through the stratified sequence – spanning hundreds to thousands of years – and provides the earliest archaeological evidence of sustained hominin involvement with fleshed animal remains (i.e., persistent carnivory), a foraging adaptation central to many models of hominin evolution. PMID:23637995

  16. Earliest known Australian Tertiary mammal fauna

    NASA Astrophysics Data System (ADS)

    Godthelp, Henk; Archer, Michael; Cifelli, Richard; Hand, Suzanne J.; Gilkeson, Coral F.

    1992-04-01

    REMAINS of Early Eocene vertebrates from freshwater clays near Murgon, southeastern Queensland, represent Australia's oldest marsupials, bats, non-volant placentals, frogs, madtsoiid snakes, trionychid turtles1and birds. Radiometric dating of illites forming part of the matrix of the mammal-bearing zone has given a minimum age estimate of 54.6 +/- 0.05 x 106 years, which is roughly twice as old as any marsupials previously known from Australia2 and well before the 38 million year (Myr) separation of Australia from Antarctica/South America3. All marsupials so far known from the Tingamarra Local Fauna are more derived (being dilambdodont) than peradectids. None of them is clearly a member of a previously known Australian family, but some could be uniquely plesiomorphic dasyuroids or perameloids. Another is autapomorphically specialized and indicative of at least partial isolation of the Australian portion of Gondwana. Here we report on the discovery of a tooth of the earliest non-volant placental known from Australia, Tingamarra porterorum gen.et sp. nov., which seems to be a condylarth-like placental mammal. The presence of non-volant placentals in the Early Tertiary of Australia challenges a common presumption that marsupials dominated Australia's therian assemblages because of failure of such placentals to reach Australia before the Late Tertiary.

  17. Natural Learning: The Life of an Environmental Schoolyard. Creating Environments for Rediscovering Nature's Way of Teaching.

    ERIC Educational Resources Information Center

    Moore, Robin C.; Wong, Herb H.

    The "Environment Yard" project is a 10-year effort to transform an ordinary asphalt schoolyard into a lush, naturalized environment. This book describes the project from which a natural extension of the classroom was created, reducing student boredom and antisocial behavior as they became engaged in the landscape. It instructs on how to naturalize…

  18. Earliest evidence for the use of pottery.

    PubMed

    Craig, O E; Saul, H; Lucquin, A; Nishida, Y; Taché, K; Clarke, L; Thompson, A; Altoft, D T; Uchiyama, J; Ajimoto, M; Gibbs, K; Isaksson, S; Heron, C P; Jordan, P

    2013-04-18

    Pottery was a hunter-gatherer innovation that first emerged in East Asia between 20,000 and 12,000 calibrated years before present (cal bp), towards the end of the Late Pleistocene epoch, a period of time when humans were adjusting to changing climates and new environments. Ceramic container technologies were one of a range of late glacial adaptations that were pivotal to structuring subsequent cultural trajectories in different regions of the world, but the reasons for their emergence and widespread uptake are poorly understood. The first ceramic containers must have provided prehistoric hunter-gatherers with attractive new strategies for processing and consuming foodstuffs, but virtually nothing is known of how early pots were used. Here we report the chemical analysis of food residues associated with Late Pleistocene pottery, focusing on one of the best-studied prehistoric ceramic sequences in the world, the Japanese Jōmon. We demonstrate that lipids can be recovered reliably from charred surface deposits adhering to pottery dating from about 15,000 to 11,800 cal bp (the Incipient Jōmon period), the oldest pottery so far investigated, and that in most cases these organic compounds are unequivocally derived from processing freshwater and marine organisms. Stable isotope data support the lipid evidence and suggest that most of the 101 charred deposits analysed, from across the major islands of Japan, were derived from high-trophic-level aquatic food. Productive aquatic ecotones were heavily exploited by late glacial foragers, perhaps providing an initial impetus for investment in ceramic container technology, and paving the way for further intensification of pottery use by hunter-gatherers in the early Holocene epoch. Now that we have shown that it is possible to analyse organic residues from some of the world's earliest ceramic vessels, the subsequent development of this critical technology can be clarified through further widespread testing of hunter

  19. Evaluation of different end-of-life management alternatives for used natural cork stoppers through life cycle assessment.

    PubMed

    Demertzi, Martha; Dias, Ana Cláudia; Matos, Arlindo; Arroja, Luís Manuel

    2015-12-01

    An important aspect of sustainable development is the implementation of effective and sustainable waste management strategies. The present study focuses on a Life Cycle Assessment (LCA) approach to different waste management strategies for natural cork stoppers, namely incineration at a municipal solid waste incinerator, landfilling in a sanitary landfill, and recycling. In the literature, there are no LCA studies analyzing in detail the end-of-life stage of natural cork stoppers as well as other cork products. In addition, cork is usually treated as wood at the end-of-life stage. Thus, the outcome of this study can provide an important insight into this matter. The results showed that different management alternatives, namely incineration and recycling, could be chosen depending on the impact category considered. The former alternative presented the best environmental results in the impact categories of climate change, ozone depletion and acidification, while the latter for photochemical ozone formation and mineral and fossil resource depletion. The landfilling alternative did not present the best environmental performance in any of the impact categories. However, when the biogenic carbon dioxide emission was assessed for the climate change category, the landfilling alternative was found to be the most effective since most of the biogenic carbon would be permanently stored in the cork products and not emitted into the atmosphere. A sensitivity analysis was performed and the results showed that there are various parameters that can significantly influence the results (e.g., carbon content in cork and decay rate of cork in the landfill). Thus, LCA studies should include a detailed description concerning their assumptions when the end-of-life stage is included in the boundaries since they can influence the results, and furthermore, to facilitate the comparison of different end-of-life scenarios. The present study and the obtained results could be useful for the

  20. 29 CFR 4022.10 - Earliest PBGC Retirement Date.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... after the date the participant reaches age 55, the Earliest PBGC Retirement Date for the participant is... reaches age 55, the Earliest PBGC Retirement Date for the participant is the date the participant reaches... participant reaches age 55, the PBGC will make a determination, under the facts and circumstances, as...

  1. World assumptions, posttraumatic stress and quality of life after a natural disaster: A longitudinal study

    PubMed Central

    2012-01-01

    Background Changes in world assumptions are a fundamental concept within theories that explain posttraumatic stress disorder. The objective of the present study was to gain a greater understanding of how changes in world assumptions are related to quality of life and posttraumatic stress symptoms after a natural disaster. Methods A longitudinal study of 574 Norwegian adults who survived the Southeast Asian tsunami in 2004 was undertaken. Multilevel analyses were used to identify which factors at six months post-tsunami predicted quality of life and posttraumatic stress symptoms two years post-tsunami. Results Good quality of life and posttraumatic stress symptoms were negatively related. However, major differences in the predictors of these outcomes were found. Females reported significantly higher quality of life and more posttraumatic stress than men. The association between level of exposure to the tsunami and quality of life seemed to be mediated by posttraumatic stress. Negative perceived changes in the assumption “the world is just” were related to adverse outcome in both quality of life and posttraumatic stress. Positive perceived changes in the assumptions “life is meaningful” and “feeling that I am a valuable human” were associated with higher levels of quality of life but not with posttraumatic stress. Conclusions Quality of life and posttraumatic stress symptoms demonstrate differences in their etiology. World assumptions may be less specifically related to posttraumatic stress than has been postulated in some cognitive theories. PMID:22742447

  2. Computer Modeling of the Earliest Cellular Structures and Functions

    NASA Astrophysics Data System (ADS)

    Pohorille, Andrew

    2000-03-01

    In the absence of extinct or extant record of protocells (the earliest ancestors of contemporary cells), the most direct way to test ourunderstanding of the origin of cellular life is to construct laboratory models of protocells. Such efforts are currently underway in the NASA Astrobiology Program. They are accompanied by computational studies aimed at explaining self-organization of simple molecules into ordered structures and developing designs for molecules that perform protocellular functions. Many of these functions, such as import of nutrients, capture and storage of energy, and response to changes in the environment are carried out by proteins bound to membranes. We will discuss a series of large-scale, molecular-level computer simulations which demonstrate (a) how small proteins (peptides)organize themselves into ordered structures at water-membrane interfaces and insert into membranes, (b) how these peptides aggregate to form membrane-spanning structures (e.g. channels), and (c) by what mechanisms such aggregates perform essential protocellular functions, such as proton transport of protons across cell walls, a key step in cellular bioenergetics. The simulations were performed using the molecular dynamics method, in which Newton's equations of motion for each atom in the system are solved iteratively. The problems of interest required simulations on multi-nanosecond time scales, which corresponded to 10^6-10^8 time steps.

  3. Computer Modeling of the Earliest Cellular Structures and Functions

    NASA Technical Reports Server (NTRS)

    Pohorille, Andrew; Chipot, Christophe; Schweighofer, Karl

    2000-01-01

    In the absence of extinct or extant record of protocells (the earliest ancestors of contemporary cells). the most direct way to test our understanding of the origin of cellular life is to construct laboratory models of protocells. Such efforts are currently underway in the NASA Astrobiology Program. They are accompanied by computational studies aimed at explaining self-organization of simple molecules into ordered structures and developing designs for molecules that perform proto-cellular functions. Many of these functions, such as import of nutrients, capture and storage of energy. and response to changes in the environment are carried out by proteins bound to membrane< We will discuss a series of large-scale, molecular-level computer simulations which demonstrate (a) how small proteins (peptides) organize themselves into ordered structures at water-membrane interfaces and insert into membranes, (b) how these peptides aggregate to form membrane-spanning structures (eg. channels), and (c) by what mechanisms such aggregates perform essential proto-cellular functions, such as proton transport of protons across cell walls, a key step in cellular bioenergetics. The simulations were performed using the molecular dynamics method, in which Newton's equations of motion for each item in the system are solved iteratively. The problems of interest required simulations on multi-nanosecond time scales, which corresponded to 10(exp 6)-10(exp 8) time steps.

  4. Long life, natural death. The learned ideal of dying in late medieval commentaries on Avicenna's Canon.

    PubMed

    van 't Land, Karine

    2014-01-01

    Within late medieval learned medicine, natural death functioned both as a theoretical concept and as a goal for practice. Late medieval commentaries on Avicenna's Canon are used as source material in this study, in order to investigate the ways in which these learned medical authors envisaged natural death. The findings are compared to descriptions of natural death by natural philosophers, and to ideals of dying in broader medieval culture. According to the physicians, natural death was caused by the extinction of innate heat, due to a lack of innate moisture. They discussed natural death in relation to regimen, as the right regimen protected the body's heat and moisture, and thus helped a patient to keep natural death aloof. So, in order to think about natural death, the physicians turned to the whole of life, during which heat dried out moisture and regimens ought to be followed. By contrast, natural philosophers tended to focus on the moment of death itself. The comparison of natural death with the Good Death in broad medieval culture highlights the amoral nature of the natural death. PMID:25577929

  5. Father Nature: Fathers as Guides to the Natural World. American Land & Life Series.

    ERIC Educational Resources Information Center

    Piper, Paul S., Ed.; Tag, Stan, Ed.

    This book contains 19 personal essays on the role that fathers play in fostering connections between their children and the natural world. Written from the perspective of adult children or of fathers themselves, most essays show how outdoor activities, particularly hunting and fishing, are replicated across the generations and serve to foster…

  6. Life-cycle greenhouse gas emissions of shale gas, natural gas, coal, and petroleum.

    PubMed

    Burnham, Andrew; Han, Jeongwoo; Clark, Corrie E; Wang, Michael; Dunn, Jennifer B; Palou-Rivera, Ignasi

    2012-01-17

    The technologies and practices that have enabled the recent boom in shale gas production have also brought attention to the environmental impacts of its use. It has been debated whether the fugitive methane emissions during natural gas production and transmission outweigh the lower carbon dioxide emissions during combustion when compared to coal and petroleum. Using the current state of knowledge of methane emissions from shale gas, conventional natural gas, coal, and petroleum, we estimated up-to-date life-cycle greenhouse gas emissions. In addition, we developed distribution functions for key parameters in each pathway to examine uncertainty and identify data gaps such as methane emissions from shale gas well completions and conventional natural gas liquid unloadings that need to be further addressed. Our base case results show that shale gas life-cycle emissions are 6% lower than conventional natural gas, 23% lower than gasoline, and 33% lower than coal. However, the range in values for shale and conventional gas overlap, so there is a statistical uncertainty whether shale gas emissions are indeed lower than conventional gas. Moreover, this life-cycle analysis, among other work in this area, provides insight on critical stages that the natural gas industry and government agencies can work together on to reduce the greenhouse gas footprint of natural gas. PMID:22107036

  7. Assessment of dose during the life cycle of natural stone production.

    PubMed

    Turtiainen, Tuukka; Weltner, Anne

    2007-01-01

    The environmental impact during the life cycle of natural stone production was studied. One of the points of interest was radiation. Natural stone samples from 23 quarries were surveyed for the radioactivity. One quarry was selected for a case study where the effective dose to the workers was assessed. The use of these stones in buildings was also evaluated with respect to the excess dose caused to the residents. According to the results the excess effective dose to the workers does not exceed 1 mSv a(-1) at the quarries. In buildings, all natural stones studied can be used safely as surfacing materials. PMID:17525055

  8. Eliciting adults' earliest memories: does it matter how we ask the question?

    PubMed

    Jack, Fiona; Hayne, Harlene

    2007-08-01

    For more than a century, psychologists have debated the age of adults' earliest memories. To date, estimates have ranged from 2 to 6-8 years of age. In this experiment, we examined how the nature of the question used to elicit early memories influenced the age from which memories were retrieved. Young adults provided written descriptions of autobiographical memories and estimated their age at the time of each remembered event. One group was asked to report their six earliest memories. Three other groups were asked to describe memories associated with particular cue words. They were asked to report memories from any time in their lives, to report childhood memories, or to report their earliest memory associated with each word. When participants were asked to report their earliest memories, there was no effect of cue words on the ages of the memories reported. When participants were asked to sample different epochs of their lives, however, the age of the memories they reported differed substantially: asking participants to recall early memories yielded a higher density of events that occurred during the traditional childhood amnesia period. Thus, many early childhood memories may remain available, but may be less accessible than later memories. These data show that the way in which we ask adults to report their early memories affects the age of the memories that are reported, and thus influences the conclusions that may be drawn about the boundary of childhood amnesia. PMID:17654279

  9. Earliest evidence of pollution by heavy metals in archaeological sites

    NASA Astrophysics Data System (ADS)

    Monge, Guadalupe; Jimenez-Espejo, Francisco J.; García-Alix, Antonio; Martínez-Ruiz, Francisca; Mattielli, Nadine; Finlayson, Clive; Ohkouchi, Naohiko; Sánchez, Miguel Cortés; de Castro, Jose María Bermúdez; Blasco, Ruth; Rosell, Jordi; Carrión, José; Rodríguez-Vidal, Joaquín; Finlayson, Geraldine

    2015-09-01

    Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called “Anthropocene”. According to its heavy metal concentration, these sediments meet the present-day standards of “contaminated soil”. Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence.

  10. Earliest evidence of pollution by heavy metals in archaeological sites.

    PubMed

    Monge, Guadalupe; Jimenez-Espejo, Francisco J; García-Alix, Antonio; Martínez-Ruiz, Francisca; Mattielli, Nadine; Finlayson, Clive; Ohkouchi, Naohiko; Sánchez, Miguel Cortés; de Castro, Jose María Bermúdez; Blasco, Ruth; Rosell, Jordi; Carrión, José; Rodríguez-Vidal, Joaquín; Finlayson, Geraldine

    2015-01-01

    Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called "Anthropocene". According to its heavy metal concentration, these sediments meet the present-day standards of "contaminated soil". Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence. PMID:26388184

  11. Earliest evidence of pollution by heavy metals in archaeological sites

    PubMed Central

    Monge, Guadalupe; Jimenez-Espejo, Francisco J.; García-Alix, Antonio; Martínez-Ruiz, Francisca; Mattielli, Nadine; Finlayson, Clive; Ohkouchi, Naohiko; Sánchez, Miguel Cortés; de Castro, Jose María Bermúdez; Blasco, Ruth; Rosell, Jordi; Carrión, José; Rodríguez-Vidal, Joaquín; Finlayson, Geraldine

    2015-01-01

    Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called “Anthropocene”. According to its heavy metal concentration, these sediments meet the present-day standards of “contaminated soil”. Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence. PMID:26388184

  12. Hybrid life-cycle assessment of natural gas based fuel chains for transportation.

    PubMed

    Strømman, Anders Hammer; Solli, Christian; Hertwich, Edgar G

    2006-04-15

    This research compares the use of natural gas, methanol, and hydrogen as transportation fuels. These three fuel chains start with the extraction and processing of natural gas in the Norwegian North Sea and end with final use in Central Europe. The end use is passenger transportation with a sub-compact car that has an internal combustion engine for the natural gas case and a fuel cell for the methanol and hydrogen cases. The life cycle assessment is performed by combining a process based life-cycle inventory with economic input-output data. The analysis shows that the potential climate impacts are lowest for the hydrogen fuel scenario with CO2 deposition. The hydrogen fuel chain scenario has no significant environmental disadvantage compared to the other fuel chains. Detailed analysis shows that the construction of the car contributes significantly to most impact categories. Finally, it is shown how the application of a hybrid inventory model ensures a more complete inventory description compared to standard process-based life-cycle assessment. This is particularly significant for car construction which would have been significantly underestimated in this study using standard process life-cycle assessment alone. PMID:16683626

  13. Earliest land plants created modern levels of atmospheric oxygen.

    PubMed

    Lenton, Timothy M; Dahl, Tais W; Daines, Stuart J; Mills, Benjamin J W; Ozaki, Kazumi; Saltzman, Matthew R; Porada, Philipp

    2016-08-30

    The progressive oxygenation of the Earth's atmosphere was pivotal to the evolution of life, but the puzzle of when and how atmospheric oxygen (O2) first approached modern levels (∼21%) remains unresolved. Redox proxy data indicate the deep oceans were oxygenated during 435-392 Ma, and the appearance of fossil charcoal indicates O2 >15-17% by 420-400 Ma. However, existing models have failed to predict oxygenation at this time. Here we show that the earliest plants, which colonized the land surface from ∼470 Ma onward, were responsible for this mid-Paleozoic oxygenation event, through greatly increasing global organic carbon burial-the net long-term source of O2 We use a trait-based ecophysiological model to predict that cryptogamic vegetation cover could have achieved ∼30% of today's global terrestrial net primary productivity by ∼445 Ma. Data from modern bryophytes suggests this plentiful early plant material had a much higher molar C:P ratio (∼2,000) than marine biomass (∼100), such that a given weathering flux of phosphorus could support more organic carbon burial. Furthermore, recent experiments suggest that early plants selectively increased the flux of phosphorus (relative to alkalinity) weathered from rocks. Combining these effects in a model of long-term biogeochemical cycling, we reproduce a sustained +2‰ increase in the carbonate carbon isotope (δ(13)C) record by ∼445 Ma, and predict a corresponding rise in O2 to present levels by 420-400 Ma, consistent with geochemical data. This oxygen rise represents a permanent shift in regulatory regime to one where fire-mediated negative feedbacks stabilize high O2 levels. PMID:27528678

  14. The earliest known fully quadrupedal sirenian.

    PubMed

    Domning, D P

    2001-10-11

    Modern seacows (manatees and dugongs; Mammalia, Sirenia) are completely aquatic, with flipperlike forelimbs and no hindlimbs. Here I describe Eocene fossils from Jamaica that represent nearly the entire skeleton of a new genus and species of sirenian--the most primitive for which extensive postcranial remains are known. This animal was fully capable of locomotion on land, with four well-developed legs, a multivertebral sacrum, and a strong sacroiliac articulation that could support the weight of the body out of water as in land mammals. Aquatic adaptations show, however, that it probably spent most of its time in the water. Its intermediate form thus illustrates the evolutionary transition between terrestrial and aquatic life. Similar to contemporary primitive cetaceans, it probably swam by spinal extension with simultaneous pelvic paddling, unlike later sirenians and cetaceans, which lost the hindlimbs and enlarged the tail to serve as the main propulsive organ. Together with fossils of later sirenians elsewhere in the world, these new specimens document one of the most marked examples of morphological evolution in the vertebrate fossil record. PMID:11675784

  15. Life cycle water consumption for shale gas and conventional natural gas.

    PubMed

    Clark, Corrie E; Horner, Robert M; Harto, Christopher B

    2013-10-15

    Shale gas production represents a large potential source of natural gas for the nation. The scale and rapid growth in shale gas development underscore the need to better understand its environmental implications, including water consumption. This study estimates the water consumed over the life cycle of conventional and shale gas production, accounting for the different stages of production and for flowback water reuse (in the case of shale gas). This study finds that shale gas consumes more water over its life cycle (13-37 L/GJ) than conventional natural gas consumes (9.3-9.6 L/GJ). However, when used as a transportation fuel, shale gas consumes significantly less water than other transportation fuels. When used for electricity generation, the combustion of shale gas adds incrementally to the overall water consumption compared to conventional natural gas. The impact of fuel production, however, is small relative to that of power plant operations. The type of power plant where the natural gas is utilized is far more important than the source of the natural gas. PMID:24004382

  16. Life politics, nature and the state: Giddens' sociological theory and The Politics of Climate Change.

    PubMed

    Thorpe, Charles; Jacobson, Brynna

    2013-03-01

    Anthony Giddens' The Politics of Climate Change represents a significant shift in the way in which he addresses ecological politics. In this book, he rejects the relevance of environmentalism and demarcates climate-change policy from life politics. Giddens addresses climate change in the technocratic mode of simple rather than reflexive modernization. However, Giddens' earlier sociological theory provides the basis for a more reflexive understanding of climate change. Climate change instantiates how, in high modernity, the existential contradiction of the human relationship with nature returns in new form, expressed in life politics and entangled with the structural contradictions of the capitalist state. The interlinking of existential and structural contradiction is manifested in the tension between life politics and the capitalist nation-state. This tension is key for understanding the failures so far of policy responses to climate change. PMID:23488703

  17. Life-cycle assessment of diesel, natural gas and hydrogen fuel cell bus transportation systems

    NASA Astrophysics Data System (ADS)

    Ally, Jamie; Pryor, Trevor

    The Sustainable Transport Energy Programme (STEP) is an initiative of the Government of Western Australia, to explore hydrogen fuel cell technology as an alternative to the existing diesel and natural gas public transit infrastructure in Perth. This project includes three buses manufactured by DaimlerChrysler with Ballard fuel cell power sources operating in regular service alongside the existing natural gas and diesel bus fleets. The life-cycle assessment (LCA) of the fuel cell bus trial in Perth determines the overall environmental footprint and energy demand by studying all phases of the complete transportation system, including the hydrogen infrastructure, bus manufacturing, operation, and end-of-life disposal. The LCAs of the existing diesel and natural gas transportation systems are developed in parallel. The findings show that the trial is competitive with the diesel and natural gas bus systems in terms of global warming potential and eutrophication. Emissions that contribute to acidification and photochemical ozone are greater for the fuel cell buses. Scenario analysis quantifies the improvements that can be expected in future generations of fuel cell vehicles and shows that a reduction of greater than 50% is achievable in the greenhouse gas, photochemical ozone creation and primary energy demand impact categories.

  18. Land-Energy Nexus: Life Cycle Land Use of Natural Gas-Fired Electricity

    NASA Astrophysics Data System (ADS)

    Heath, G.; Jordaan, S.; Macknick, J.; Mohammadi, E.; Ben-Horin, D.; Urrea, V.

    2014-12-01

    Comparisons of the land required for different types of energy are challenging due to the fact that upstream land use of fossil fuel technologies is not well characterized. This research focuses on improving estimates of the life cycle land use of natural gas-fired electricity through the novel combination of inventories of the location of natural gas-related infrastructure, satellite imagery analysis and gas production data. Land area per unit generation is calculated as the sum of natural gas life cycle stages divided by the throughput of natural gas, combined with the land use of the power plant divided by the generation of the power plant. Five natural gas life cycle stages are evaluated for their area: production, gathering, processing, transmission and disposal. The power plant stage is characterized by a thermal efficiency ηth, which converts MegaJoules (MJ) to kilowatt hours (kWh). We focus on seven counties in the Barnett shale region in Texas that represent over 90% of total Barnett Shale gas production. In addition to assessing the gathering and transmission pipeline network, approximately 500 sites are evaluated from the five life cycle stages plus power plants. For instance, assuming a 50 foot right-of-way for transmission pipelines, this part of the Barnett pipeline network occupies nearly 26,000 acres. Site, road and water components to total area are categorized. Methods are developed to scale up sampled results for each component type to the full population of sites within the Barnett. Uncertainty and variability are charaterized. Well-level production data are examined by integrating commercial datasets with advanced methods for quantifying estimated ultimate recovery (EUR) for wells, then summed to estimate natural gas produced in an entire play. Wells that are spatially coincident are merged using ArcGIS. All other sites are normalized by an estimate of gas throughput. Prior land use estimates are used to validate the satellite imagery analysis

  19. Dietary specializations and diversity in feeding ecology of the earliest stem mammals.

    PubMed

    Gill, Pamela G; Purnell, Mark A; Crumpton, Nick; Brown, Kate Robson; Gostling, Neil J; Stampanoni, M; Rayfield, Emily J

    2014-08-21

    The origin and radiation of mammals are key events in the history of life, with fossils placing the origin at 220 million years ago, in the Late Triassic period. The earliest mammals, representing the first 50 million years of their evolution and including the most basal taxa, are widely considered to be generalized insectivores. This implies that the first phase of the mammalian radiation--associated with the appearance in the fossil record of important innovations such as heterodont dentition, diphyodonty and the dentary-squamosal jaw joint--was decoupled from ecomorphological diversification. Finds of exceptionally complete specimens of later Mesozoic mammals have revealed greater ecomorphological diversity than previously suspected, including adaptations for swimming, burrowing, digging and even gliding, but such well-preserved fossils of earlier mammals do not exist, and robust analysis of their ecomorphological diversity has previously been lacking. Here we present the results of an integrated analysis, using synchrotron X-ray tomography and analyses of biomechanics, finite element models and tooth microwear textures. We find significant differences in function and dietary ecology between two of the earliest mammaliaform taxa, Morganucodon and Kuehneotherium--taxa that are central to the debate on mammalian evolution. Morganucodon possessed comparatively more forceful and robust jaws and consumed 'harder' prey, comparable to extant small-bodied mammals that eat considerable amounts of coleopterans. Kuehneotherium ingested a diet comparable to extant mixed feeders and specialists on 'soft' prey such as lepidopterans. Our results reveal previously hidden trophic specialization at the base of the mammalian radiation; hence even the earliest mammaliaforms were beginning to diversify--morphologically, functionally and ecologically. In contrast to the prevailing view, this pattern suggests that lineage splitting during the earliest stages of mammalian evolution was

  20. Lessons from the life history of natural fertility societies on child growth and maturation.

    PubMed

    Gawlik, Aneta; Hochberg, Ze'ev

    2012-01-01

    During the evolution of hominids, childhood and adolescence have been added as new life-history phases. The transition from infancy to childhood (ICT) confers a predictive adaptive response to energetic cues that strongly influence adult height, whereas the transition from juvenility to adolescence establishes longevity and the age of fertility. Evolutionary short-term adaptations to energy crises apparently use epigenetic mechanisms that defer the ICT, culminating in short stature. The study of hunter-gatherers gives us an indication of pre-demographic transition populations and their life style that prevailed for 99% of homo's evolution. The secular trend for receding age of pubertal development has been an adaptive response to positive environmental cues in terms of energy balance. In natural fertility preindustrial societies with limited access to modern contraception and health care, and whose economies are primarily subsistence-based, most resources are invested as somatic capital in human body size and fertility. Here we review results from databases for natural fertility societies, with the information on life history, population density, height and body mass, indices of adolescence and fertility. By using them it was possible to verify the ICT model as well as to explore pubertal parameters that are related to evolutionary fitness. They confirmed that body size was adaptively smaller in hostile environments, and was tightly associated with reproductive fitness. PMID:22717937

  1. Bringing human, social, and natural capital to life: practical consequences and opportunities.

    PubMed

    Fisher, William P

    2011-01-01

    Capital is defined mathematically as the abstract meaning brought to life in the two phases of the development of "transferable representations," which are the legal, financial, and scientific instruments we take for granted in almost every aspect of our daily routines. The first, conceptual and gestational, and the second, parturitional and maturational, phases in the creation and development of capital are contrasted. Human, social, and natural forms of capital should be brought to life with at least the same amounts of energy and efficiency as have been invested in manufactured and liquid capital, and property. A mathematical law of living capital is stated. Two examples of well-measured human capital are offered. The paper concludes with suggestions for the ways that future research might best capitalize on the mathematical definition of capital. PMID:21512213

  2. Naturally-occurring expressive suppression in daily life depletes executive functioning.

    PubMed

    Franchow, Emilie I; Suchy, Yana

    2015-02-01

    The depleting impact of experimentally manipulated expressive suppression (ES) on cognition (especially executive functioning and related processes) has been well established (Baumeister, 2002a). However, the impact of ES that occurs naturally in the course of daily life has not been examined. Sixty two adults (M = 22.89 years old) completed questions about recent ES burden (over the past 2 weeks and on the test day) and completed cognitive measures assessing executive functioning, working memory, and speed of information processing. Individuals with higher-than-usual burden of ES on the test day exhibited poorer executive performance and those with high ES over the past 2 weeks exhibited poorer processing speed above and beyond depression, suggesting that ES burden as it occurs in the course of daily life is associated with compromised cognitive performance. PMID:25111882

  3. Malnutrition in Early Life and Adult Mental Health: Evidence From a Natural Experiment

    PubMed Central

    Huang, Cheng; Phillips, Michael R.; Zhang, Yali; Zhang, Jingxuan; Shi, Qichang; Song, Zhiqiang; Ding, Zhijie; Pang, Shutao; Martorell, Reynaldo

    2013-01-01

    As natural experiments, famines provide a unique opportunity to test the health consequences of nutritional deprivation during the critical period of early life. Using data on 4,972 Chinese born between 1956 and 1963 who participated in a large mental health epidemiology survey conducted between 2001 and 2005, we investigated the potential impact of famine exposure in utero and during the early postnatal life on adult mental illness. The risk of mental illness was assessed with the 12-item General Health Questionnaire (GHQ-12) and eight other risk factors, and the famine impact on adult mental illness was estimated by difference-in-difference models. Results show that compared with women born in 1963, women born during the famine years (1959–1961) had higher GHQ scores (increased by 0.95 points; CI: 0.26, 1.65) and increased risk of mental illness (OR= 2.80; CI: 1.23, 6.39); those born in 1959 were the most affected and had GHQ scores 1.52 points higher (CI: 0.42, 2.63) and an OR for mental illness of 4.99 (CI: 1.68, 14.84). Compared to men in the 1963 birth cohort, men born during the famine had lower GHQ scores (decreased by 0.89 points; CI: −1.59, −0.20) and a nonsignificant decrease in the risk of mental illness (OR = 0.60; CI: 0.26, 1.40). We speculate that the long-term consequences of early-life famine exposure include both the selection of the hardiest and the enduring deleterious effects of famine on those who survive. The greater biological vulnerability and stronger natural selection in utero of male versus female fetuses during severe famine may result in a stronger selection effect among men than women, obscuring the deleterious impact of famine exposure on the risk of mental illness in men later in life. PMID:23313495

  4. Earliest Recollections and Birth Order: Two Adlerian Exercises.

    ERIC Educational Resources Information Center

    Parrott, Les

    1992-01-01

    Presents two exercises designed to demonstrate the influence of two Adlerian principles on personality. Includes exercises dealing with birth order and earliest recollection. Concludes that the exercises actively demonstrate major concepts for counseling courses in Adlerian psychotherapy. Reports that students rated both exercises highly, with…

  5. Predicting the service life of platinized titanium anodes in hypochlorite production from natural waters

    SciTech Connect

    Mikhailova, L.A.; Khodkevich, S.D.; Yakimenko, L.M.; Rabinovich, A.B.

    1987-07-01

    Radiotracer measurements were used to study the rates of anodic dissolution of the platinum coatings as functions of the three major electrolysis parameters: the current density, electrolyte composition, and temperature. A mathematical expression was obtained from which one can calculate for any specific set of electrolysis conditions the wear of the platinum coating and the amount of platinum that must be plated in order to obtain the required service life of the electrolyzer in the production of active-chlorine solutions from natural waters.

  6. Natural autoantibodies in Bos taurus calves during the first twelve weeks of life.

    PubMed

    Mayasari, N; Van Knegsel, A T M; de Vries Reilingh, G; Kemp, B; Parmentier, H K

    2016-10-01

    Natural autoantibodies (NAAb) have a role in maintaining physiological homeostasis and prevention of infections, and have been found in mammalian species tested so far. Albeit NAAb levels rise with age, little is known about the origin, function, regulation and initiation of NAAb in young animals. The present study addressed the presence of IgM and IgG NAAb binding glutamate dehydrogenase (GD), carbonic anhydrase (CA), myosin (MYO) and transferrin (TRANS) from before drinking colostrum until the first 12 weeks of life in plasma of female calves. In addition, NAAb to these four self-antigens were also measured in colostrum and in plasma of their mothers during three weeks before calving. Titers of NAAb binding GD, CA, MYO and TRANS were detected in plasma of cows before calving, in colostrum, and in plasma of calves before and after drinking of colostrum. Levels of NAAb in colostrum were positively related with levels of NAAb in plasma of cows. Before colostrum intake, levels of NAAb in plasma of calves were not related with levels of NAAb in plasma of their mother but were influenced by parity of their mother. After colostrum intake, levels of NAAb in plasma of calves in the first week of life were positively related with levels of NAAb in colostrum. Low NAAb levels in colostrum were related with low NAAb in plasma of calves in the first week of life, but after two weeks of life the relation between colostrum and plasma of calves was absent. In conclusion, NAAb are already present in the unborn calf, and levels of neonatal NAAb during the early weeks of life are affected by levels of maternal NAAb obtained via colostrum. PMID:27496745

  7. 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.

  8. Ichnotaxonomy of the Laetoli trackways: The earliest hominin footprints

    NASA Astrophysics Data System (ADS)

    Meldrum, D. J.; Lockley, Martin G.; Lucas, Spencer G.; Musiba, Charles

    2011-04-01

    At 3.6 Ma, the Laetoli Pliocene hominin trackways are the earliest direct evidence of hominin bipedalism. Three decades since their discovery, not only is the question of their attribution still discussed, but marked differences in interpretation concerning the footprints' qualitative features and the inferred nature of the early hominin foot morphology remain. Here, we establish a novel ichnotaxon, Praehominipes laetoliensis, for these tracks and clarify the distinctions of these footprints from those of later hominins, especially modern humans. We also contrast hominin, human, and ape footprints to establish morphological features of these footprints correlated with a midtarsal break versus a stiff longitudinal arch. Original photos, including stereo photographs, and casts of footprints from the 1978 Laetoli excavation, confirm midtarsal flexibility, and repeatedly indicate an associated midfoot pressure ridge. In contrast, the modern human footprint reflects the derived arched-foot architecture, combined with a stiff-legged striding gait. Fossilized footprints of unshod modern human pedestrians in Hawaii and Nicaragua unambiguously illustrate these contrasts. Some points of comparisons with ape footprints are complicated by a variable hallucal position and the distinct manner of ape facultative bipedalism. In contrast to the comparatively rigid platform of the modern human foot, midtarsal flexibility is present in the chimpanzee foot. In ape locomotion, flexion at the transverse tarsal joint, referred to as the "midtarsal break," uncouples the respective functions of the prehensile forefoot and the propulsive hindfoot during grasp-climbing. At some point after the transition to habitual bipedalism, these grasp-climb adaptations, presumed to be present in the last common ancestor of apes and humans, were initially compromised by the loss of divergence of the hallux. An analogous trajectory is evident along an array of increasingly terrestrial extant ape species

  9. Genes and life-style factors in BELFAST nonagenarians: Nature, Nurture and Narrative.

    PubMed

    Rea, Jennifer Nicola M; Carvalho, Ashley; McNerlan, Susan E; Alexander, H Denis; Rea, Irene Maeve

    2015-10-01

    Understanding how to 'Age Longer and Age Well' is a priority for people personally, for populations globally and for government policy. Nonagenarians are the oldest members of our societies and survivors of their generation. Approximately 10 % of nonagenarians reach 90 years and beyond in good condition and seem to have a combination of both age-span and health-span. But what are the factors which help people reach their ninetieth birthday and beyond in good condition? Are they genetics, as in 'nature', or do they depend on 'nurture' and are related to environment, or are both factors inextricably intertwined within the concept of behavioural genetics? Nonagenarians have rich life experiences that can teach us much about ageing well; they are reservoirs of genetic, life-style and behavioural information which can help dissect out how to live not only longer but better. Personal family history and narrative are powerful tools that help to determine familial traits, beliefs and social behaviours and when used in parallel with new biotechnology methods inform and elaborate causality. Here we present themes and insights from personal narrative enquiry from nonagenarian participants from the Belfast Elderly Longitudinal Free-living Ageing STudy (BELFAST) about factors they consider important for good quality ageing and relate these insights to the emerging genetics and life-style evidence associated with healthy longevity. PMID:25773008

  10. Probabilistic Forecasting of Life and Economic Losses due to Natural Disasters

    NASA Astrophysics Data System (ADS)

    Barton, C. C.; Tebbens, S. F.

    2014-12-01

    The magnitude of natural hazard events such as hurricanes, tornadoes, earthquakes, and floods are traditionally measured by wind speed, energy release, or discharge. In this study we investigate the scaling of the magnitude of individual events of the 20th and 21stcentury in terms of economic and life losses in the United States and worldwide. Economic losses are subdivided into insured and total losses. Some data sets are inflation or population adjusted. Forecasts associated with these events are of interest to insurance, reinsurance, and emergency management agencies. Plots of cumulative size-frequency distributions of economic and life loss are well-fit by power functions and thus exhibit self-similar scaling. This self-similar scaling property permits use of frequent small events to estimate the rate of occurrence of less frequent larger events. Examining the power scaling behavior of loss data for disasters permits: forecasting the probability of occurrence of a disaster over a wide range of years (1 to 10 to 1,000 years); comparing losses associated with one type of disaster to another; comparing disasters in one region to similar disasters in another region; and, measuring the effectiveness of planning and mitigation strategies. In the United States, life losses due to flood and tornado cumulative-frequency distributions have steeper slopes, indicating that frequent smaller events contribute the majority of losses. In contrast, life losses due to hurricanes and earthquakes have shallower slopes, indicating that the few larger events contribute the majority of losses. Disaster planning and mitigation strategies should incorporate these differences.

  11. LIFE, Life Investigation For Enceladus

    NASA Astrophysics Data System (ADS)

    Tsou, Peter; Kanic, I.; Lane, C.; Sotin, C.; Spilker, L.; Spilker, T.; Strange, N.

    2009-09-01

    Enceladus, a small icy moon of Saturn, is one of NASA outer planet life search targets and unique in its current active jets. As with comets, this enables a low-cost flyby sample return mission like STARDUST. Samples from Enceladus will expand our in-depth knowledge of "life” and allow us to effectively plan for future missions. Cassini found Enceladus’ jets composed of fine icy particules and hydrocarbons. Saturn's E ring is sustained by these jets for at least the last 300 years. Clearly there is a subsurface heat source generating such jets. Several theories for the origin of life on Earth would also apply to Enceladus; thus, obtaining the samples from the plume will provide breakthrough understandings of the nature of current or past life markers. The highly detailed analyses of Apollo and STARDUST samples revolutionized our knowledge of the Moon and comets and provided fundamental insights into remarkable processes that occur early in the formation of the Solar System. These in-depth analyses are not possible with astronomical remote sensing or in-situ instrumentations. Since the duration of these plumes is unknown, it is imperative to capture these samples by the earliest flight opportunity- the Discovery AO by the fall of 2009. For LIFE, we have a trajectory to encounter the plume at less than 4 km/s ensuring a more gentle capture of organics than STARDUST at 6 km/s. With less than 14-year mission duration, the samples can be returned to Earth before 2029. By capitalizing on the STARDUST heritage of design-to-cost mindset, the mission cost can be controlled. For cost reduction, the upcoming Discovery AO offers unique free ASRGs and allows the use of Jupiter for gravity assist.

  12. ESA on the trail of the earliest stars

    NASA Astrophysics Data System (ADS)

    2003-01-01

    hi-res Size hi-res: 3054 kb Credits: NASA Simulated image of the distant Universe as seen by JWST This is a simulated image showing the abilities of the NGST. Compared to the Hubble Space Telescope the NGST will improve our 'sight' considerably. Artist's impression of JWST hi-res Size hi-res: 3960 kb Credits: ESA Artist's impression of JWST Image shows an artist's impression of the selected design for the JWST spacecraft. Northrop Grumman and Ball Aerospace are the prime contractors for JWST. Gamma-ray burst as seen by Integral Credits: ESA. Original image by the Integral IBIS team. Image processing by ESA/ECF Gamma-ray burst as seen by Integral A gamma-ray burst seen by ESA's Integral satellite. This picture was taken using the Imager on Board the Integral Satellite (IBIS). Astronomers suspect that some gamma-ray bursts are the explosions of individual population III stars. Astronomers know they must have been out there: only in this way could they solve the riddle of the origin and composition of stars in today's Universe. A couple of ESA missions will help astronomers search for this elusive population. When the Universe formed, there was just hydrogen and helium. Chemical elements such as oxygen, carbon, iron and so on were forged later, in the nuclear furnaces at the hearts of stars and then cast into space at the end of the star's life. Astronomers call everything that is heavier than helium a 'metal'. All stars we can observe today contain metals. The youngest contain the most metals and astronomers call them population I stars. The oldest contain only some metals and astronomers call these population II stars. Where do these metals come from? Astronomers have theorised that a first generation of stars, which they call population III, must have existed in the early Universe. This first generation of stars must have formed using only hydrogen and helium, the only elements available in the early cosmic history. After living for 'just' a million years, they

  13. Chemical and archaeological evidence for the earliest cacao beverages

    PubMed Central

    Henderson, John S.; Joyce, Rosemary A.; Hall, Gretchen R.; Hurst, W. Jeffrey; McGovern, Patrick E.

    2007-01-01

    Chemical analyses of residues extracted from pottery vessels from Puerto Escondido in what is now Honduras show that cacao beverages were being made there before 1000 B.C., extending the confirmed use of cacao back at least 500 years. The famous chocolate beverage served on special occasions in later times in Mesoamerica, especially by elites, was made from cacao seeds. The earliest cacao beverages consumed at Puerto Escondido were likely produced by fermenting the sweet pulp surrounding the seeds. PMID:18024588

  14. [Shi Ji Yao Yu, the earliest extant monograph on TCM nursery].

    PubMed

    Fu, W

    1999-07-01

    Nursery of traditional Chinese medicine (NTCM) has a long history. However, due to the change and influence of the era, society, life style, and many other factors, NTCM did not become an independent discipline for a long period. Although there have been many articles about NTCM appearing in various historical books of traditional Chinese medicine, books specializing on NTCM were not available until later. The earliest ancient book, which is still currently available, describing NTCM in details is the "Shi Ji Yao Yu" written by Qian Xiang in the Qing Dynasty. The book explains the key issues of taking care of a patient's emotional well-being, life style, diet, illness, and drug administration which are of great practical significance now and for the future. PMID:11624096

  15. Extending storage life of fresh-cut apples using natural products and their derivatives.

    PubMed

    Buta, J G; Moline, H E; Spaulding, D W; Wang, C Y

    1999-01-01

    Prevention of browning of apples slices has been difficult to achieve because of the rapidity of the enzymatic oxidation of phenolic substrates even under reduced atmospheric pressure storage. Combinations of enzymatic inhibitors, reducing agents, and antimicrobial compounds containing calcium to extend storage life were tested to decrease the browning of Red Delicious apple slices stored at 5 and 10 degrees C under normal atmospheric conditions. Treatments were devised to prevent browning for up to 5 weeks at 5 degrees C with no apparent microbial growth using dipping solutions of compounds derived from natural products consisting of 4-hexylresorcinol, isoascorbic acid, a sulfur-containing amino acid (N-acetylcysteine), and calcium propionate. Analyses of organic acids and the major sugars revealed that the slices treated with the combinations of antibrowning compounds retained higher levels of malic acid and had no deterioration in sugar levels at 5 and 10 degrees C, indicating that higher quality was maintained during storage. PMID:10563838

  16. Interfamily variation in amphibian early life-history traits: raw material for natural selection?

    PubMed Central

    Hopkins, Gareth R; Gall, Brian G; French, Susannah S; Brodie, Edmund D

    2012-01-01

    The embryonic development and time to hatching of eggs can be highly adaptive in some species, and thus under selective pressure. In this study, we examined the underlying interfamily variation in hatching timing and embryonic development in a population of an oviparous amphibian, the rough-skinned newt (Taricha granulosa). We found significant, high variability in degree of embryonic development and hatching timing among eggs from different females. Patterns of variation were present regardless of temperature. We also could not explain the differences among families by morphological traits of the females or their eggs. This study suggests that the variation necessary for natural selection to act upon is present in the early life history of this amphibian. PMID:22957168

  17. Teleomechanism redux? Functional physiology and hybrid models of life in early modern natural philosophy.

    PubMed

    Wolfe, Charles T

    2014-01-01

    The distinction between 'mechanical' and 'teleological' has been familiar since Kant; between a fully mechanistic, quantitative science of Nature and a teleological, qualitative approach to living beings, namely 'organisms' understood as purposive or at least functional entities. The beauty of this distinction is that it apparently makes intuitive sense and maps onto historico-conceptual constellations in the life sciences, regarding the status of the body versus that of the machine. I argue that the mechanism-teleology distinction is imprecise and flawed using examples including the 'functional' features present even in Cartesian physiology, the Oxford Physiologists' work on circulation and respiration, the fact that the model of the 'body-machine' is not a mechanistic reduction of organismic properties to basic physical properties but is focused on the uniqueness of organic life; and the concept of 'animal economy' in vitalist medicine, which I present as a 'teleomechanistic' concept of organism (borrowing a term of Lenoir's which he applied to nineteenth-century embryology)--neither mechanical nor teleological. PMID:25707100

  18. Primal Eukaryogenesis: On the Communal Nature of Precellular States, Ancestral to Modern Life

    PubMed Central

    Egel, Richard

    2012-01-01

    This problem-oriented, exploratory and hypothesis-driven discourse toward the unknown combines several basic tenets: (i) a photo-active metal sulfide scenario of primal biogenesis in the porespace of shallow sedimentary flats, in contrast to hot deep-sea hydrothermal vent conditions; (ii) an inherently complex communal system at the common root of present life forms; (iii) a high degree of internal compartmentalization at this communal root, progressively resembling coenocytic (syncytial) super-cells; (iv) a direct connection from such communal super-cells to proto-eukaryotic macro-cell organization; and (v) multiple rounds of micro-cellular escape with streamlined reductive evolution-leading to the major prokaryotic cell lines, as well as to megaviruses and other viral lineages. Hopefully, such nontraditional concepts and approaches will contribute to coherent and plausible views about the origins and early life on Earth. In particular, the coevolutionary emergence from a communal system at the common root can most naturally explain the vast discrepancy in subcellular organization between modern eukaryotes on the one hand and both archaea and bacteria on the other. PMID:25382122

  19. Process based life-cycle assessment of natural gas from the Marcellus Shale.

    PubMed

    Dale, Alexander T; Khanna, Vikas; Vidic, Radisav D; Bilec, Melissa M

    2013-05-21

    The Marcellus Shale (MS) represents a large potential source of energy in the form of tightly trapped natural gas (NG). Producing this NG requires the use of energy and water, and has varying environmental impacts, including greenhouse gases. One well-established tool for quantifying these impacts is life-cycle assessment (LCA). This study collected information from current operating companies to perform a process LCA of production for MS NG in three areas--greenhouse gas (GHG) emissions, energy consumption, and water consumption--under both present (2011-2012) and past (2007-2010) operating practices. Energy return on investment (EROI) was also calculated. Information was collected from current well development operators and public databases, and combined with process LCA data to calculate per-well and per-MJ delivered impacts, and with literature data on combustion for calculation of impacts on a per-kWh basis during electricity generation. Results show that GHG emissions through combustion are similar to conventional natural gas, with an EROI of 12:1 (90% confidence interval of 4:1-13:1), lower than conventional fossil fuels but higher than unconventional oil sources. PMID:23611587

  20. Deep microbial life in the Altmark natural gas reservoir: baseline characterization prior CO2 injection

    NASA Astrophysics Data System (ADS)

    Morozova, Daria; Shaheed, Mina; Vieth, Andrea; Krüger, Martin; Kock, Dagmar; Würdemann, Hilke

    2010-05-01

    Within the framework of the CLEAN project (CO2 Largescale Enhanced gas recovery in the Altmark Natural gas field) technical basics with special emphasis on process monitoring are explored by injecting CO2 into a gas reservoir. Our study focuses on the investigation of the in-situ microbial community of the Rotliegend natural gas reservoir in the Altmark, located south of the city Salzwedel, Germany. In order to characterize the microbial life in the extreme habitat we aim to localize and identify microbes including their metabolism influencing the creation and dissolution of minerals. The ability of microorganisms to speed up dissolution and formation of minerals might result in changes of the local permeability and the long-term safety of CO2 storage. However, geology, structure and chemistry of the reservoir rock and the cap rock as well as interaction with saline formation water and natural gases and the injected CO2 affect the microbial community composition and activity. The reservoir located at the depth of about 3500m, is characterised by high salinity fluid and temperatures up to 127° C. It represents an extreme environment for microbial life and therefore the main focus is on hyperthermophilic, halophilic anaerobic microorganisms. In consequence of the injection of large amounts of CO2 in the course of a commercial EGR (Enhanced Gas Recovery) the environmental conditions (e.g. pH, temperature, pressure and solubility of minerals) for the autochthonous microorganisms will change. Genetic profiling of amplified 16S rRNA genes are applied for detecting structural changes in the community by using PCR- SSCP (PCR-Single-Strand-Conformation Polymorphism) and DGGE (Denaturing Gradient Gel Electrophoresis). First results of the baseline survey indicate the presence of microorganisms similar to representatives from other saline, hot, anoxic, deep environments. However, due to the hypersaline and hyperthermophilic reservoir conditions, cell numbers are low, so that

  1. Implications of low natural gas prices on life cycle greenhouse gas emissions in the U.S. electricity sector

    NASA Astrophysics Data System (ADS)

    Jaramillo, P.; Venkatesh, A.; Griffin, M.; Matthews, S.

    2012-12-01

    Increased production of unconventional natural gas resources in the U.S. has drastically reduced the price of natural gas. While in 2005 prices went above 10/MMBtu, since 2011 they have been below 3/MMBtu. These low prices have encouraged the increase of natural gas utilization in the United States electricity sector. Natural gas can offset coal for power generation, reducing emissions such as greenhouse gases, sulfur and nitrogen oxides. In quantifying the benefit of offsetting coal by using natural gas, life cycle assessment (LCA) studies have shown up to 50% reductions in life cycle greenhouse gas (GHG) emissions can be expected. However, these studies predominantly use limited system boundaries that contain single individual coal and natural gas power plants. They do not consider (regional) fleets of power plants that are dispatched on the basis of their short-run marginal costs. In this study, simplified economic dispatch models (representing existing power plants in a given region) are developed for three U.S. regions - ERCOT, MISO and PJM. These models, along with historical load data are used to determine how natural gas utilization will increase in the short-term due to changes in natural gas price. The associated changes in fuel mix and life cycle GHG emissions are estimated. Results indicate that life cycle GHG emissions may, at best, decrease by 5-15% as a result of low natural gas prices, compared to almost 50% reductions estimated by previous LCAs. This study thus provides more reasonable estimates of potential reductions in GHG emissions from using natural gas instead of coal in the electricity sector in the short-term.

  2. Symptom Complexes at the Earliest Phases of Rheumatoid Arthritis: A Synthesis of the Qualitative Literature

    PubMed Central

    Stack, Rebecca J; Sahni, Melanie; Mallen, Christian D; Raza, Karim

    2013-01-01

    Objective Understanding the features and patterns of symptoms that characterize the earliest stages of rheumatoid arthritis (RA) is of considerable importance if patients are to be identified and started on treatment early. However, little is known about the characteristics of symptoms at the onset of a disease that eventually progresses to RA. Methods A systematic review of qualitative peer-reviewed publications was conducted to identify the earliest symptoms associated with the onset of RA. A total of 1,736 abstracts were searched to identify relevant publications. Twenty-six publications were identified, assessed for quality, and subjected to analysis informed by thematic and grounded theory frameworks. Results Several interacting themes describing the early symptoms of RA were identified, including swelling, pain and tenderness, stiffness, fatigue and weakness, and the emotional impact of symptoms. For each symptom, different and evolving intensities were described; in some cases, patterns of symptom onset and symptom complexes at the onset of RA were highlighted. Importantly, this review has emphasized major deficiencies in the literature. None of the studies reviewed originally aimed to explore symptoms at RA onset (often discussions about symptom onset were secondary to the study's primary aim). Also, many of the articles identified sampled people diagnosed with RA many years previously, making their recollection of symptoms at onset less reliable. Conclusion In order for clinicians to fully understand the earliest phases of disease, the nature of symptoms at onset needs to be understood. The current work represents a useful starting point, but this area needs further qualitative investigation, followed by quantitative explorations of symptom clusters and their associated features. PMID:23926091

  3. Archaeometallurgical characterization of the earliest European metal helmets

    PubMed Central

    Mödlinger, Marianne; Piccardo, Paolo; Kasztovszky, Zsolt; Kovács, Imre; Szőkefalvi-Nagy, Zoltán; Káli, György; Szilágyi, Veronika

    2013-01-01

    Archaeometric analyses on conical and decorated cap helmets from the Bronze Age are presented. The helmets are dated to the 14–12th century BC according to associated finds in hoards. Alloy composition, material structure and manufacturing processes are determined and shed light on the earliest development of weaponry production in Central and Eastern Europe. Analyses were carried out using light and dark field microscopy, SEM–EDXS, PIXE, TOF-ND and PGAA. The results allowed reconstructing the manufacturing process, the differences between the cap of the helmets and their knobs (i.e. alloy composition) and the joining technique of the two parts. PMID:26523114

  4. Mapping the lunar shadow - the earliest solar eclipse maps

    NASA Astrophysics Data System (ADS)

    van Gent, Robert H.

    The English astronomer Edmond Halley (1656-1742) is commonly credited as the first to draw and publish maps delineating the paths of totality for solar eclipses. Halley published such maps for the solar eclipses of 3 May 1715 and 22 May 1724, which were both visible from southern England. In this paper, the author presents examples of earlier maps depicting solar eclipse paths from Germany, the Netherlands and France. The earliest eclipse maps of this kind appear to be those showing the path of totality for the solar eclipses of 23 September 1699 and 12 May 1706.

  5. Analysis of Phenix end-of-life natural convection test with the MARS-LMR code

    SciTech Connect

    Jeong, H. Y.; Ha, K. S.; Lee, K. L.; Chang, W. P.; Kim, Y. I.

    2012-07-01

    The end-of-life test of Phenix reactor performed by the CEA provided an opportunity to have reliable and valuable test data for the validation and verification of a SFR system analysis code. KAERI joined this international program for the analysis of Phenix end-of-life natural circulation test coordinated by the IAEA from 2008. The main objectives of this study were to evaluate the capability of existing SFR system analysis code MARS-LMR and to identify any limitation of the code. The analysis was performed in three stages: pre-test analysis, blind posttest analysis, and final post-test analysis. In the pre-test analysis, the design conditions provided by the CEA were used to obtain a prediction of the test. The blind post-test analysis was based on the test conditions measured during the tests but the test results were not provided from the CEA. The final post-test analysis was performed to predict the test results as accurate as possible by improving the previous modeling of the test. Based on the pre-test analysis and blind test analysis, the modeling for heat structures in the hot pool and cold pool, steel structures in the core, heat loss from roof and vessel, and the flow path at core outlet were reinforced in the final analysis. The results of the final post-test analysis could be characterized into three different phases. In the early phase, the MARS-LMR simulated the heat-up process correctly due to the enhanced heat structure modeling. In the mid phase before the opening of SG casing, the code reproduced the decrease of core outlet temperature successfully. Finally, in the later phase the increase of heat removal by the opening of the SG opening was well predicted with the MARS-LMR code. (authors)

  6. Reducing Uncertainty in Life Cycle CH4 Emissions from Natural Gas using Atmospheric Inversions

    NASA Astrophysics Data System (ADS)

    Schwietzke, S.; Griffin, W.; Matthews, S.

    2012-12-01

    Methane emissions associated with the production and use of natural gas (NG) are highly uncertain because of challenges to accurately measure fugitive CH4 emissions from NG leaks and venting throughout a large and complex industry. Better understanding the CH4 emissions from the NG life cycle is important for two reasons. First, the rising interest in NG use associated with the recent development of unconventional sources, such as shale gas, may cause a shift in the future energy system from coal towards more NG. Given its relatively high greenhouse gas potency, fugitive CH4 emissions from the NG life cycle have the potential to outweigh lower CO2 emissions compared to coal use in terms of their climate impacts over the next few decades. Second, worldwide NG related CH4 emissions play a key role in understanding the global CH4 budget. According to current atmospheric inversion studies, NG and oil production account for about 12% of global CH4 emissions. However, these results largely depend on prior emissions estimates whose uncertainties are poorly documented. The objective of this research is to analyze which ranges of global fugitive CH4 emissions from the NG life cycle are reasonable given atmospheric observations as a constraint. We establish a prior global CH4 inventory for NG, oil, and coal using emissions data from the life cycle assessment (LCA) literature. This inventory includes uncertainty estimates for different fuels, world regions, and time periods based on LCA literature, which existing inventories do not account for. Furthermore, global CH4 inversion modeling will be used to test bottom-up hypotheses of high NG leakage and venting associated with the upper bound of the prior inventory. Given the use of detailed LCA emissions factors, we will test bottom-up scenarios regarding management and technology improvements over time. The emissions inventory will be established for the past decade, and inversion modeling will be carried out using NOAA

  7. Cattle Management for Dairying in Scandinavia’s Earliest Neolithic

    PubMed Central

    Gron, Kurt J.; Montgomery, Janet; Rowley-Conwy, Peter

    2015-01-01

    New evidence for cattle husbandry practices during the earliest period of the southern Scandinavian Neolithic indicates multiple birth seasons and dairying from its start. Sequential sampling of tooth enamel carbonate carbon and oxygen isotope ratio analyses and strontium isotopic provenancing indicate more than one season of birth in locally reared cattle at the earliest Neolithic Funnel Beaker (EN I TRB, 3950-3500 cal. B.C.) site of Almhov in Scania, Sweden. The main purpose for which cattle are manipulated to give birth in more than one season is to prolong lactation for the production of milk and dairy-based products. As this is a difficult, intensive, and time-consuming strategy, these data demonstrate complex farming practices by early Neolithic farmers. This result offers strong support for immigration-based explanations of agricultural origins in southern Scandinavia on the grounds that such a specialised skill set cannot represent the piecemeal incorporation of agricultural techniques into an existing hunter-gatherer-fisher economy. PMID:26146989

  8. Cattle Management for Dairying in Scandinavia's Earliest Neolithic.

    PubMed

    Gron, Kurt J; Montgomery, Janet; Rowley-Conwy, Peter

    2015-01-01

    New evidence for cattle husbandry practices during the earliest period of the southern Scandinavian Neolithic indicates multiple birth seasons and dairying from its start. Sequential sampling of tooth enamel carbonate carbon and oxygen isotope ratio analyses and strontium isotopic provenancing indicate more than one season of birth in locally reared cattle at the earliest Neolithic Funnel Beaker (EN I TRB, 3950-3500 cal. B.C.) site of Almhov in Scania, Sweden. The main purpose for which cattle are manipulated to give birth in more than one season is to prolong lactation for the production of milk and dairy-based products. As this is a difficult, intensive, and time-consuming strategy, these data demonstrate complex farming practices by early Neolithic farmers. This result offers strong support for immigration-based explanations of agricultural origins in southern Scandinavia on the grounds that such a specialised skill set cannot represent the piecemeal incorporation of agricultural techniques into an existing hunter-gatherer-fisher economy. PMID:26146989

  9. Natural mortality: Its ecology, how it shapes fish life histories, and why it may be increased by fishing

    NASA Astrophysics Data System (ADS)

    Jørgensen, Christian; Holt, Rebecca E.

    2013-01-01

    A stronger focus on natural mortality may be required to better understand contemporary changes in fish life histories and behaviour and their responses to anthropogenic drivers. Firstly, natural mortality is the selection under which fish evolved in the first place, so a theoretical understanding of effects of natural mortality alone is needed. Secondly, due to trade-offs, most organismal functions can only be achieved at some cost in terms of survival. Several trade-offs might need to be analysed simultaneously with effects on natural mortality being a common currency. Thirdly, there is scattered evidence that natural mortality has been increasing, some would say dramatically, in some fished stocks, which begs explanations. Fourthly, natural mortality most often implies transfer of mass and energy from one species to another, and therefore has foodweb and ecosystem consequences. We therefore analyse a model for evolution of fish life histories and behaviour, where state-dependent energy-allocation and growth strategies are found by optimization. Natural mortality is split into five different components, each specified as the outcome of individual traits and ecological trade-offs: a fixed baseline mortality; size-dependent predation; risk-dependent growth strategy; a fixed mortality when sexually mature; and mortality increasing with reproductive investment. The analysis is repeated with and without fishing. Each component of natural mortality has consequences for optimal life history strategies. Beyond earlier models, we show i) how the two types of reproductive mortality sometimes have similar and sometimes contrasting effects on life history evolution, ii) how ecosystem properties such as food availability and predation levels have stronger effects on optimal strategies than changing other mortality components, and iii) how expected changes in risk-dependent growth strategies are highly variable depending on the type of mortality changed.

  10. The complex nature of family support across the life span: Implications for psychological well-being.

    PubMed

    Fuller-Iglesias, Heather R; Webster, Noah J; Antonucci, Toni C

    2015-03-01

    This study examines the complex role of family networks in shaping adult psychological well-being over time. We examine the unique and interactive longitudinal influences of family structure (i.e., composition and size) and negative family relationship quality on psychological well-being among young (ages 18-34), middle-aged (ages 35-49), and older adults (ages 50+). A sample of 881 adults (72% White; 26% Black) was drawn from the longitudinal Social Relations, Age, and Health Study. Structural equation modeling indicated that among young and middle-aged adults, increasing family negativity was associated with increases in depressive symptoms over time. In contrast, among older adults, lowered proportion of family in network and an increasing number of family members in the network (i.e., family size) were associated with decreases in depressive symptoms. These findings were moderated by family negativity. Among older adults with low family negativity, having a lower proportion of family and larger family size were associated with decreasing depressive symptoms, but there was no effect among those reporting high family negativity. Overall, these results contribute to an increased understanding of the complex, developmental nature of how family support influences well-being across the life span and highlights unique age differences. PMID:25602936

  11. Reducing Uncertainty in Life Cycle CH4 Emissions from Natural Gas using Atmospheric Inversions

    NASA Astrophysics Data System (ADS)

    Schwietzke, S.; Griffin, W.; Matthews, H.; Bruhwiler, L.

    2013-12-01

    Rising interest in natural gas (NG) as a potentially cleaner alternative to coal and successful tapping of unconventional resources in North America, particularly shale gas, have led to numerous life cycle assessment (LCA) studies revisiting NG leakage rates, i.e., the fraction of produced NG, mostly methane, emitted to the atmosphere, intentionally or unintentionally. Accurately quantifying leakage rates of the full NG life cycle - extraction, processing, transport, and distribution - is challenging due to the size and complexity of the NG industry. Recent U.S. LCA estimates suggest that current NG leakage could be as high as 8% and 6%, from shale and conventional NG, respectively, compared to less than 2% in the latest EPA GHG emission inventory. Reducing uncertainty in the NG leakage rate is important for assessing potential climate benefits of NG over coal, and for understanding the global CH4 budget. The objective of this research is to analyze which ranges of the global average NG leakage rate are reasonable given existing atmospheric observations. We establish detailed prior global CH4 and C2H6 emission inventory scenarios for NG, oil, and coal using emissions data from the LCA literature including uncertainty estimates. Global CH4 and C2H6 inverse box-modeling is used to test the above hypotheses of various global NG leakage rates over the period 1984-2011. Forward simulations with NOAA's CarbonTracker-CH4 (CT-CH4) model provide additional spatial and seasonal information about CH4 atmospheric distribution. Box model inversion results indicate worst-case scenarios of current (2010) global average NG leakage rates of 7% (128 Tg CH4/yr) and 5% (92 Tg CH4/yr) based on CH4 isotope and C2H6 observations, respectively, as well as available raw gas composition data. Worst-case assumptions include upper bound estimates of the global CH4 and C2H6 budget, lower bound literature estimates of all CH4 and C2H6 sources other than NG simultaneously, and absence of a

  12. Characterization of the deep microbial life in the Altmark natural gas reservoir

    NASA Astrophysics Data System (ADS)

    Morozova, D.; Alawi, M.; Vieth-Hillebrand, A.; Kock, D.; Krüger, M.; Wuerdemann, H.; Shaheed, M.

    2010-12-01

    Within the framework of the CLEAN project (CO2 Largescale Enhanced gas recovery in the Altmark Natural gas field) technical basics with special emphasis on process monitoring are explored by injecting CO2 into a gas reservoir. Our study focuses on the investigation of the in-situ microbial community of the Rotliegend natural gas reservoir in the Altmark, located south of the city Salzwedel, Germany. In order to characterize the microbial life in the extreme habitat we aim to localize and identify microbes including their metabolism influencing the creation and dissolution of minerals. The ability of microorganisms to speed up dissolution and formation of minerals might result in changes of the local permeability and the long-term safety of CO2 storage. However, geology, structure and chemistry of the reservoir rock and the cap rock as well as interaction with saline formation water and natural gases and the injected CO2 affect the microbial community composition and activity. The reservoir located at the depth of approximately 3500 m, is characterised by high salinity (420 g/l) and temperatures up to 127°C. It represents an extreme environment for microbial life and therefore the main focus is on hyperthermophilic, halophilic anaerobic microorganisms. In consequence of the injection of large amounts of CO2 in the course of a commercial EGR (Enhanced Gas Recovery), the environmental conditions (e.g. pH, temperature, pressure and solubility of minerals) for the autochthonous microorganisms will change. Genetic profiling of amplified 16S rRNA genes are applied for detecting structural changes in the community by using PCR- SSCP (PCR-Single-Strand-Conformation Polymorphism), DGGE (Denaturing Gradient Gel Electrophoresis) and 16S rRNA cloning. First results of the baseline survey indicate the presence of microorganisms similar to representatives from other deep environments. The sequence analyses revealed the presence of several H2-oxidising bacteria (Hydrogenophaga sp

  13. Elevated Appraisals of the Negative Impact of Naturally Occurring Life Events: A Risk Factor for Depressive and Anxiety Disorders

    ERIC Educational Resources Information Center

    Espejo, Emmanuel Peter; Hammen, Constance; Brennan, Patricia A.

    2012-01-01

    The tendency to appraise naturally occurring life events (LEs) as having high negative impact may be a predisposing factor for the development of depression and anxiety disorders. In the current study, appraisals of the negative impact of recent LEs were examined in relationship to depressive and anxiety disorders in a sample of 653 adolescents…

  14. Early life history and survival of natural subyearling fall chinook salmon in the Snake and Clearwater rivers in 1995

    USGS Publications Warehouse

    Connor, William P.; Bjornn, Theodore C.; Burge, Howard L.; Garcia, Aaron P.; Rondorf, Dennis W.

    1997-01-01

    The objectives of this segment of our study were to (1) describe the early life history characteristics of naturally produced subyearling fall chinook salmon in the Snake and Clearwater rivers, and (2) estimate survival for juvenile fall chinook salmon emigrating from the Snake and Clearwater rivers to the tail race of Lower Granite Dam.

  15. Developmental Investigation of the Domain-Specific Nature of the Life Satisfaction Construct across the Post-School Transition

    ERIC Educational Resources Information Center

    Chen, Xidan; Morin, Alexandre J. S.; Parker, Philip D.; Marsh, Herbert W.

    2015-01-01

    This study evaluated the nature of the life satisfaction construct with an emphasis on the comparison between a global or domain-specific operationalization during the transition from adolescence to adulthood. A combination of person-centered and variable-centered methods were used to analyze 7 waves of data covering the postschool transition from…

  16. The earliest known tyrannosaur from the Lower Cretaceous of Thailand

    NASA Astrophysics Data System (ADS)

    Buffetaut, Eric; Suteethorn, Varavudh; Tong, Haiyan

    1996-06-01

    THE Tyrannosauridae were the dominant large carnivorous dinosaurs in Asia (excluding India) and western North America during the Late Cretaceous period1-3. Most of them are from the Campanian and Maastrichtian ages, and very little is known about their earlier history, although scanty remains have been reported from the early part of the Upper Cretaceous4-7. We describe a newly discovered incomplete skeleton of a large theropod from the Early Cretaceous Sao Khua Formation of northeastern Thailand as an early and primitive representative of the Tyrannosauridae. This new taxon, which is at least 20 million years older than the earliest previously known tyranno-saurids, suggests that the early evolution of tyrannosaurids may have taken place in Asia.

  17. Ultrasonic hearing and echolocation in the earliest toothed whales.

    PubMed

    Park, Travis; Fitzgerald, Erich M G; Evans, Alistair R

    2016-04-01

    The evolution of biosonar (production of high-frequency sound and reception of its echo) was a key innovation of toothed whales and dolphins (Odontoceti) that facilitated phylogenetic diversification and rise to ecological predominance. Yet exactly when high-frequency hearing first evolved in odontocete history remains a fundamental question in cetacean biology. Here, we show that archaic odontocetes had a cochlea specialized for sensing high-frequency sound, as exemplified by an Oligocene xenorophid, one of the earliest diverging stem groups. This specialization is not as extreme as that seen in the crown clade. Paired with anatomical correlates for high-frequency signal production in Xenorophidae, this is strong evidence that the most archaic toothed whales possessed a functional biosonar system, and that this signature adaptation of odontocetes was acquired at or soon after their origin. PMID:27072406

  18. Investigating the earliest epochs of the Milky Way halo

    NASA Astrophysics Data System (ADS)

    Starkenburg, Else; Starkenburg

    2016-08-01

    Resolved stellar spectroscopy can obtain knowledge about chemical enrichment processes back to the earliest times, when the oldest stars were formed. In this contribution I will review the early (chemical) evolution of the Milky Way halo from an observational perspective. In particular, I will discuss our understanding of the origin of the peculiar abundance patterns in various subclasses of extremely metal-poor stars, taking into account new data from our abundance and radial velocity monitoring programs, and their implications for our understanding of the formation and early evolution of both the Milky Way halo and the satellite dwarf galaxies therein. I conclude by presenting the ``Pristine'' survey, a program on the Canada-France-Hawaii Telescope to study this intriguing epoch much more efficiently.

  19. The earliest fossil evidence for sexual dimorphism in primates

    NASA Technical Reports Server (NTRS)

    Krishtalka, Leonard; Stucky, Richard K.; Beard, K. C.

    1990-01-01

    Recently obtained material of the early Eocene primate Notharctus venticolus, including two partial skulls from a single stratigraphic horizon, provides the geologically earliest evidence of sexual dimorphism in canine size and shape in primates and the only unequivocal evidence for such dimorphism in strepsirhines. By analogy with living platyrrhines, these data suggest that Notharctus venticolus may have lived in polygynous social groups characterized by a relatively high level of intermale competition for mates and other limited resources. The anatomy of the upper incisors and related evidence imply that Notharctus is not as closely related to extant lemuriform primates as has been recently proposed. The early Eocene evidence for canine sexual dimorphism reported here, and its occurrence in a nonanthropoid, indicates that in the order Primates such a condition is either primitive or evolved independently more than once.

  20. Observing the Earliest Galaxies: Looking for the Sources of Reionization

    NASA Astrophysics Data System (ADS)

    Illingworth, Garth

    2015-04-01

    Systematic searches for the earliest galaxies in the reionization epoch finally became possible in 2009 when the Hubble Space Telescope was updated with a powerful new infrared camera during the final Shuttle servicing mission SM4 to Hubble. The reionization epoch represents the last major phase transition of the universe and was a major event in cosmic history. The intense ultraviolet radiation from young star-forming galaxies is increasingly considered to be the source of the photons that reionized intergalactic hydrogen in the period between the ``dark ages'' (the time before the first stars and galaxies at about 100-200 million years after the Big Bang) and the end of reionization around 800-900 million years. Yet finding and measuring the earliest galaxies in this era of cosmic dawn has proven to a challenging task, even with Hubble's new infrared camera. I will discuss the deep imaging undertaken by Hubble and the remarkable insights that have accrued from the imaging datasets taken over the last decade on the Hubble Ultra-Deep Field (HUDF, HUDF09/12) and other regions. The HUDF datasets are central to the story and have been assembled into the eXtreme Deep Field (XDF), the deepest image ever from Hubble data. The XDF, when combined with results from shallower wide-area imaging surveys (e.g., GOODS, CANDELS) and with detections of galaxies from the Frontier Fields, has provided significant insights into the role of galaxies in reionization. Yet many questions remain. The puzzle is far from being fully solved and, while much will done over the next few years, the solution likely awaits the launch of JWST. NASA/STScI Grant HST-GO-11563.

  1. Earliest evidence for commensal processes of cat domestication

    PubMed Central

    Hu, Yaowu; Hu, Songmei; Wang, Weilin; Wu, Xiaohong; Marshall, Fiona B.; Chen, Xianglong; Hou, Liangliang; Wang, Changsui

    2014-01-01

    Domestic cats are one of the most popular pets globally, but the process of their domestication is not well understood. Near Eastern wildcats are thought to have been attracted to food sources in early agricultural settlements, following a commensal pathway to domestication. Early evidence for close human–cat relationships comes from a wildcat interred near a human on Cyprus ca. 9,500 y ago, but the earliest domestic cats are known only from Egyptian art dating to 4,000 y ago. Evidence is lacking from the key period of cat domestication 9,500–4,000 y ago. We report on the presence of cats directly dated between 5560–5280 cal B.P. in the early agricultural village of Quanhucun in Shaanxi, China. These cats were outside the wild range of Near Eastern wildcats and biometrically smaller, but within the size-range of domestic cats. The δ13C and δ15N values of human and animal bone collagen revealed substantial consumption of millet-based foods by humans, rodents, and cats. Ceramic storage containers designed to exclude rodents indicated a threat to stored grain in Yangshao villages. Taken together, isotopic and archaeological data demonstrate that cats were advantageous for ancient farmers. Isotopic data also show that one cat ate less meat and consumed more millet-based foods than expected, indicating that it scavenged among or was fed by people. This study offers fresh perspectives on cat domestication, providing the earliest known evidence for commensal relationships between people and cats. PMID:24344279

  2. Origin and earliest state of the earth's hydrosphere

    SciTech Connect

    Cogley, J.G.; Henderson-Sellers, A.

    1984-05-01

    The origin and earliest history of the earth's hydrosphere, the inventory of excess volatiles defined by Rubey in 1951, can be constrained within wide but useful limits by a consideration of empirical and theoretical evidence from astrophysics and geology. Models for the evolution of the solar system from the protoplanetary nebula and for the growth of the earth to its present dimensions suggest quite strongly that the hydrosphere came into being during accretion. Its format, with H/sub 2/O mostly in the oceans, CO/sub 2/ mostly in sediments, and a residual atmosphere dominated by N/sub 2/, CO/sub 2/, and H/sub 2/O was established at a very early data and has persisted without large, destabilizing climatic excursions until the present day. Alternative accounts of early history, in which the earth either loses a massive primordial atmosphere or acquires its secondary atmosphere by gradual degassing, seem improbable on the basis of a series of circumstantial but cumulatively persuasive arguments. The difficulty of dissipating a massive atmosphere of solar composition in reasonable times, the likelihood that accretion was a highly energetic process and that it triggered early segregation of the core, and the tendency of the planet to accumulate volatiles preferentially in the later stages of accretion are examples of arguments favoring an early origin for the hydrosphere. Several geological isotope systems which can be sampled today require early separation of the atmosphere and probably the hydrosphere ass a whole; these systems recorrd radiogenic enrichment patterns in the noble gases and stable isotope fractionations which suggest an early origin of the biosphere. Certain geological indicators of atmsopheric composition. and the broadly equable character of the rock record, are also consistent with a hydrosphere established in the earliest stages of history and having an initial neutral or weakly reduced composition.

  3. Boosting subsurface life: is subseafloor sediment a natural catalyst for radiolytic hydrogen production?

    NASA Astrophysics Data System (ADS)

    Sauvage, J.; Graham, D.; Spivack, A. J.; Dunlea, A. G.; Murray, R. W.; D'Hondt, S.

    2014-12-01

    Naturally occurring production of molecular hydrogen (H2) by water radiolysis may be a fundamentally important source of electron donors (energy) for life in subsurface environments where organic matter is scarce. Previous studies with very high gamma radiation rates and wet mineral phases have reported high H2 production relative to production from water radiolysis in the absence of solid phases. Numerical calculations by other previous studies have predicted enhanced H2 production from seawater radiolysis relative to pure water radiolysis, due to the interaction of anions with hydroxyl radicals. Given these reports, the potential catalytic influences of solid and dissolved chemical phases on radiolytic H2 production need to be carefully quantified in order to fully evaluate the role of radiolytic H2 as a microbial energy source. For such quantification, we undertook gamma-irradiation experiments with pure water, deep ocean water and mixtures (slurries, φ = 0.85) of seawater with: North Pacific abyssal clay and calcareous oozes, coastal sediment, zirconium dioxide, and zeolite. We carried out our experiments at the Rhode Island Nuclear Science Center using a 37Cesium source at low dose rates (up to 0.1 Gy/hr). Our results to date include the following. First, the per-dose radiolytic H2 yield of pure water at low dose rates is directly comparable to the per-dose yield at much higher dose rates (ca. 1 kGy/hr); this result indicates that H2 production rate is linearly related to radiation dose rate across four orders of magnitude. Second, there is no statistically significant difference (90% confidence limit) between the radiolytic H2 yield from pure water and that from seawater; this result rules out influence of abundant seawater salts on H2 yield from water radiolysis. Third, H2 production from a mixture of abyssal clay and seawater is 25% higher than the yield from pure water. This enhanced yield is consistent with catalysis of radiolytic H2 production by

  4. Stimulating Growth and Renewal of Public Libraries: The Natural Life Cycle as Framework. ERIC Digest.

    ERIC Educational Resources Information Center

    Parry, Norm

    This digest explores the life cycle of public libraries, presenting a "life stages" model and highlighting characteristics of each stage. It provides specific advice on what can be done in each stage to energize the library with "stage-appropriate" action. The characteristics that mark the Birth/Infant stage include: driving enthusiasm and effort…

  5. Curriculum as natural history: A life-history case study of an alternative science learning program

    NASA Astrophysics Data System (ADS)

    Windward, Rolfe

    The aim of this study is to further our understanding of the nexus between individual development and conceptions of science curriculum with particular emphasis upon root metaphors. The initial conceptual springboard is based upon the rather consistent conflation of selectionist (Darwinian) and developmental cosmologies in most scientific thinking about complex systems. A partial goal of this study then being the development of a visual metaphor that offers a more coherent heuristic of what it means to be a knowing individual within a changing ecosocial reality. This is a paradigmatic examination and it is conjectured that the root assumptions underlying the bulk of curriculum theory are unrealistic, that the appearance of stability in curriculum and practice is largely a byproduct of misclassification or even category error, and that reconceptualizing curriculum as a description of an adaptive system rather than a system-by-design will assist in unpacking a number of problems including the so-called theory-practice gap. The basic procedure is a life-history case study of seven participants--three female high school students, three male high school students, and their teacher--tracked between three learning contexts: the classroom, an extracurricular science "institute," and a virtual astronomy class. The biography of the researcher is incorporated both as a matter of methodology and as a matter of interventionist stance. It is concluded that the 'science institute' embodied a number of innovative features, including more equality among all participants, that also allowed masking-off of countervailing forces perceived as antithetical to its own development. Its organization was not stable but constituted a strongly expansive instrument in the individuation of all participants, allowing the students to more clearly visualize the multiple natures of science and themselves as individuals and scientists. It also allowed the teacher involved to leverage change in his

  6. Comparison of life cycle greenhouse gases from natural gas pathways for medium and heavy-duty vehicles.

    PubMed

    Tong, Fan; Jaramillo, Paulina; Azevedo, Inês M L

    2015-06-16

    The low-cost and abundant supply of shale gas in the United States has increased the interest in using natural gas for transportation. We compare the life cycle greenhouse gas (GHG) emissions from different natural gas pathways for medium and heavy-duty vehicles (MHDVs). For Class 8 tractor-trailers and refuse trucks, none of the natural gas pathways provide emissions reductions per unit of freight-distance moved compared to diesel trucks. When compared to the petroleum-based fuels currently used in these vehicles, CNG and centrally produced LNG increase emissions by 0-3% and 2-13%, respectively, for Class 8 trucks. Battery electric vehicles (BEVs) powered with natural gas-produced electricity are the only fuel-technology combination that achieves emission reductions for Class 8 transit buses (31% reduction compared to the petroleum-fueled vehicles). For non-Class 8 trucks (pick-up trucks, parcel delivery trucks, and box trucks), BEVs reduce emissions significantly (31-40%) compared to their diesel or gasoline counterparts. CNG and propane achieve relatively smaller emissions reductions (0-6% and 19%, respectively, compared to the petroleum-based fuels), while other natural gas pathways increase emissions for non-Class 8 MHDVs. While using natural gas to fuel electric vehicles could achieve large emission reductions for medium-duty trucks, the results suggest there are no great opportunities to achieve large emission reductions for Class 8 trucks through natural gas pathways with current technologies. There are strategies to reduce the carbon footprint of using natural gas for MHDVs, ranging from increasing vehicle fuel efficiency, reducing life cycle methane leakage rate, to achieving the same payloads and cargo volumes as conventional diesel trucks. PMID:25938939

  7. Use of lycopene as a natural antioxidant in extending the shelf-life of anhydrous cow milk fat.

    PubMed

    Siwach, Ruby; Tokas, Jayanti; Seth, Raman

    2016-05-15

    Oxidative rancidity in anhydrous cow milk fat leads to reduction in its shelf life. Use of synthetic antioxidants is prevalent in dairy industry to prevent the development of rancidity. Keeping in view the increasing demand for natural additives, the present study was carried out to explore the potential of lycopene as a natural antioxidant in anhydrous cow milk fat. Lycopene at five different levels (30, 60, 90, 120 and 150 ppm) and butylated hydroxyl anisole (200 ppm), were incorporated in anhydrous cow milk fat. Potential of lycopene extract to enhance the shelf life of anhydrous cow milk fat was evaluated by measuring Free Fatty Acids, peroxide value, Thiobarbituric Acid value and color value during 12 months of storage at ambient conditions (30°C). Lycopene significantly (p<0.05) prevented the development of oxidative rancidity. Lycopene containing samples scored significantly higher in terms of sensory attributes as compared to control. PMID:26776006

  8. Potential Biomarkers of the Earliest Clinical Stages of Parkinson's Disease

    PubMed Central

    Alieva, Anelya Kh.; Filatova, Elena V.; Karabanov, Aleksey V.; Illarioshkin, Sergey N.; Slominsky, Petr A.; Shadrina, Maria I.

    2015-01-01

    Parkinson's disease (PD) is a widespread neurodegenerative disorder. Despite the intensive studies of this pathology, in general, the picture of the etiopathogenesis has still not been clarified fully. To understand better the mechanisms underlying the pathogenesis of PD, we analyzed the expression of 10 genes in the peripheral blood of treated and untreated patients with PD. 35 untreated patients with PD and 12 treated patients with Parkinson's disease (Hoehn and Yahr scores 1-2) were studied. An analysis of the mRNA levels of ATP13A2, PARK2, PARK7, PINK1, LRRK2, SNCA, ALDH1A1, PDHB, PPARGC1A, and ZNF746 genes in the peripheral blood of patients was carried out using reverse transcription followed by real-time PCR. A statistically significant and specific increase by more than 1.5-fold in the expression of the ATP13A2, PARK7, and ZNF746 genes was observed in patients with PD. Based on these results, it can be suggested that the upregulation of the mRNA levels of ATP13A2, PARK7, and ZNF746 in untreated patients in the earliest clinical stages can also be observed in the preclinical stages of PD, and that these genes can be considered as potential biomarkers of the preclinical stage of PD. PMID:26483988

  9. A Jurassic mammaliaform and the earliest mammalian evolutionary adaptations.

    PubMed

    Zhou, Chang-Fu; Wu, Shaoyuan; Martin, Thomas; Luo, Zhe-Xi

    2013-08-01

    The earliest evolution of mammals and origins of mammalian features can be traced to the mammaliaforms of the Triassic and Jurassic periods that are extinct relatives to living mammals. Here we describe a new fossil from the Middle Jurassic that has a mandibular middle ear, a gradational transition of thoracolumbar vertebrae and primitive ankle features, but highly derived molars with a high crown and multiple roots that are partially fused. The upper molars have longitudinal cusp rows that occlude alternately with those of the lower molars. This specialization for masticating plants indicates that herbivory evolved among mammaliaforms, before the rise of crown mammals. The new species shares the distinctive dental features of the eleutherodontid clade, previously represented only by isolated teeth despite its extensive geographic distribution during the Jurassic. This eleutherodontid was terrestrial and had ambulatory gaits, analogous to extant terrestrial mammals such as armadillos or rock hyrax. Its fur corroborates that mammalian integument had originated well before the common ancestor of living mammals. PMID:23925238

  10. The Earliest Comet Photographs: Usherwood and Bond for Donati 1858

    NASA Astrophysics Data System (ADS)

    Pasachoff, J. M.; Olson, R. J. M.

    1995-12-01

    The first known photographs of a comet were taken in 1858. The earliest astronomical telescopic photographs, daguerreotypes from 1850-51, had been made only when the violet focus of telescopes was found. Tracking remained a problem preventing astronomical objects from being photographed. When the Harvard refractor's tracking was improved in 1858, it was used by the Bonds and colleagues to photograph Comet Donati on a collodion plate. The plate remains in the archives of the Harvard College Observatory, though the image shows only very faintly and no tail can be seen. Bond was scooped the previous night by the commercial English photographer W. Usherwood, who used a portrait camera at a much lower focal ratio to capture the comet's tail. The plate was seen and evaluated by W.C. Bond. No further comet photography took place until 1881, when P.J.C. Janssen and J.W. Draper took the first generally recognized photographs of a comet, followed by D. Gill's photographs of the Great September comet of 1882. This work was sponsored by two Senior Research Grants from the Getty Grant Program.

  11. The earliest pterodactyloid and the origin of the group.

    PubMed

    Andres, Brian; Clark, James; Xu, Xing

    2014-05-01

    The pterosaurs were a diverse group of Mesozoic flying reptiles that underwent a body plan reorganization, adaptive radiation, and replacement of earlier forms midway through their long history, resulting in the origin of the Pterodactyloidea, a highly specialized clade containing the largest flying organisms. The sudden appearance and large suite of morphological features of this group were suggested to be the result of it originating in terrestrial environments, where the pterosaur fossil record has traditionally been poor [1, 2], and its many features suggested to be adaptations to those environments [1, 2]. However, little evidence has been available to test this hypothesis, and it has not been supported by previous phylogenies or early pterodactyloid discoveries. We report here the earliest pterosaur with the diagnostic elongate metacarpus of the Pterodactyloidea, Kryptodrakon progenitor, gen. et sp. nov., from the terrestrial Middle-Upper Jurassic boundary of Northwest China. Phylogenetic analysis confirms this species as the basalmost pterodactyloid and reconstructs a terrestrial origin and a predominantly terrestrial history for the Pterodactyloidea. Phylogenetic comparative methods support this reconstruction by means of a significant correlation between wing shape and environment also found in modern flying vertebrates, indicating that pterosaurs lived in or were at least adapted to the environments in which they were preserved. PMID:24768054

  12. Buried Impact Basins and the Earliest History of Mars

    NASA Technical Reports Server (NTRS)

    Frey, H. V.

    2003-01-01

    The "Quasi-Circular Depressions" (QCDs) seen in MOLA data which have little or no visible appearance in image data have been interpreted as buried impact basins on Mars. These have important implications for the age of the lowland crust, what mechanisms could produce the crustal dichotomy, and the existence of crust older than the oldest observed surface units on Mars. A global survey of large QCDs using high resolution MOLA data now available has provided further details of the earliest history of Mars. The lowlands are of Early Noachian age, slightly younger than the buried highlands and definitely older than the exposed highland surface. A depopulation of large visible basins at diameters 800 to 1300 km suggests some global scale event early in martian history, maybe related to the formation of the lowlands and/or the development of Tharsis. A suggested early disappearance of the global magnetic field can be placed within a temporal sequence of formation of the very largest impact basins.

  13. Aurorae: The earliest datable observation of the aurora borealis

    NASA Astrophysics Data System (ADS)

    Stephenson, F. Richard; Willis, David M.; Hallinan, Thomas J.

    2004-12-01

    The Late Babylonian astronomical texts, discovered at the site of Babylon (32.5°N, 44.4°E) more than a century ago, contain what is probably the earliest reliable account of the aurora borealis. A clay tablet recording numerous celestial observations made by the official astronomers during the 37th year of King Nebuchadnezzar II (568/567 BC) describes an unusual ``red glow'' in the sky at night; the exact date of this observation corresponds to the night of 12/13 March in 567 BC. The most likely interpretation of the phenomenon is an auroral display. This event occurred several centuries before the first clearly identifiable observation of the aurora from elsewhere in the world, namely China in 193 BC. The Babylonian auroral observation is remarkable in the sense that it is one of a series of carefully recorded astronomical observations, for each of which the year, month and day are known precisely. This observation occurred at a time when the geomagnetic (dipole) latitude of Babylon was about 41°N compared with the present value of 27.5°N, suggesting a higher auroral incidence at Babylon in 567 BC than at present.

  14. Defining the Earliest Pathological Changes of Alzheimer’s Disease

    PubMed Central

    Vickers, James C.; Mitew, Stan; Woodhouse, Adele; Fernandez-Martos, Carmen M.; Kirkcaldie, Mathew T.; Canty, Alison J.; McCormack, Graeme H.; King, Anna E.

    2016-01-01

    The prospects for effectively treating well-established dementia, such as Alzheimer’s disease (AD), are slim, due to the destruction of key brain pathways that underlie higher cognitive function. There has been a substantial shift in the field towards detecting conditions such as AD in their earliest stages, which would allow preventative or therapeutic approaches to substantially reduce risk and/or slow the progression of disease. AD is characterized by hallmark pathological changes such as extracellular Aβ plaques and intracellular neurofibrillary pathology, which selectively affect specific subclasses of neurons and brain circuits. Current evidence indicates that Aβ plaques begin to form many years before overt dementia, a gradual and progressive pathology which offers a potential target for early intervention. Early Aβ changes in the brain result in localized damage to dendrites, axonal processes and synapses, to which excitatory synapses and the processes of projection neurons are highly vulnerable. Aβ pathology is replicated in a range of transgenic models overexpressing mutant human familial AD genes (eg APP and presenilin 1). Studying the development of aberrant regenerative and degenerative changes in neuritic processes associated with Aβ plaques may represent the best opportunity to understand the relationship between the pathological hallmarks of AD and neuronal damage, and to develop early interventions to prevent, slow down or mitigate against Aβ pathology and/or the neuronal alterations that leads to cognitive impairment. PMID:26679855

  15. Ediacaran matground ecology persisted into the earliest Cambrian.

    PubMed

    Buatois, Luis A; Narbonne, Guy M; Mángano, M Gabriela; Carmona, Noelia B; Myrow, Paul

    2014-01-01

    The beginning of the Cambrian was a time of marked biological and sedimentary changes, including the replacement of Proterozoic-style microbial matgrounds by Phanerozoic-style bioturbated mixgrounds. Here we show that Ediacaran-style matground-based ecology persisted into the earliest Cambrian. Our study in the type section of the basal Cambrian in Fortune Head, Newfoundland, Canada reveals widespread microbially induced sedimentary structures and typical Ediacaran-type matground ichnofossils. Ediacara-type body fossils are present immediately below the top of the Ediacaran but are strikingly absent from the overlying Cambrian succession, despite optimal conditions for their preservation, and instead the microbial surfaces are marked by the appearance of the first abundant arthropod scratch marks in Earth evolution. These features imply that the disappearance of the Ediacara biota represents an abrupt evolutionary event that corresponded with the appearance of novel bilaterian clades, rather than a fading away owing to the gradual elimination of conditions appropriate for Ediacaran preservation. PMID:24675373

  16. The first skull of the earliest giant panda

    PubMed Central

    Jin, Changzhu; Ciochon, Russell L.; Dong, Wei; Hunt, Robert M.; Liu, Jinyi; Jaeger, Marc; Zhu, Qizhi

    2007-01-01

    Fossils of the giant panda Ailuropoda (Order Carnivora, Family Ursidae) are largely isolated teeth, mandibles, and a few rare skulls, known from the late Pliocene to late Pleistocene in China and Southeast Asia. Much of this material represents a Pleistocene chronospecies, Ailuropoda baconi, an animal larger than the living giant panda, Ailuropoda melanoleuca. The earliest certain record of Ailuropoda is the late Pliocene chronospecies, Ailuropoda microta, smaller than either A. baconi or A. melanoleuca, and previously known only from teeth and a few mandibles from karst caves in south China. Here, we report the discovery of the first skull of A. microta, establishing its cranial anatomy and demonstrating that the specialized cranial and dental adaptations of Ailuropoda for durophagous feeding behavior centered on bamboo were already evident in this late Pliocene species. The skull from Jinyin cave (Guangxi) and dental remains from other karst localities in southeastern China show that Ailuropoda microta occupied south China from ≈2 to 2.4 Myr ago after a marked global climatic deterioration. Dental and basicranial anatomy indicate a less specialized morphology early in the history of the lineage and support derivation of the giant panda from the Miocene Asian ursid Ailurarctos PMID:17578912

  17. Urban Natural Environments, Obesity, and Health-Related Quality of Life among Hispanic Children Living in Inner-City Neighborhoods

    PubMed Central

    Kim, Jun-Hyun; Lee, Chanam; Sohn, Wonmin

    2016-01-01

    Although a substantial body of literature has provided evidence supporting the positive effects of natural environments on well-being, little has been known about the specific spatial patterns of urban nature in promoting health-related quality of life (HRQOL) among children. This study assessed the association that the urban natural environment measured by landscape spatial patterns may have with obesity and HRQOL among Hispanic children. Ninety-two 4th and 5th grade students were recruited from Houston, Texas, and the Pediatric Quality of Life Inventory (PedsQL) was used to capture the children’s HRQOL. The quality of urban natural environments was assessed by quantifying the landscape spatial patterns, using landscape indices generated by Geographic Information Systems and remote sensing. From the bivariate analyses, children’s body mass index showed a significantly negative association with their HRQOL. After controlling for socio-demographic factors, the results revealed that larger and more tree areas were positively correlated with children’s HRQOL. In addition, those children living in areas with tree patches further apart from each other showed higher HRQOL. This research adds to the current multi-disciplinary area of research on environment-health relationships by investigating the roles of urban greeneries and linking their spatial structures with children’s HRQOL. PMID:26771623

  18. Urban Natural Environments, Obesity, and Health-Related Quality of Life among Hispanic Children Living in Inner-City Neighborhoods.

    PubMed

    Kim, Jun-Hyun; Lee, Chanam; Sohn, Wonmin

    2016-01-01

    Although a substantial body of literature has provided evidence supporting the positive effects of natural environments on well-being, little has been known about the specific spatial patterns of urban nature in promoting health-related quality of life (HRQOL) among children. This study assessed the association that the urban natural environment measured by landscape spatial patterns may have with obesity and HRQOL among Hispanic children. Ninety-two 4th and 5th grade students were recruited from Houston, Texas, and the Pediatric Quality of Life Inventory (PedsQL) was used to capture the children's HRQOL. The quality of urban natural environments was assessed by quantifying the landscape spatial patterns, using landscape indices generated by Geographic Information Systems and remote sensing. From the bivariate analyses, children's body mass index showed a significantly negative association with their HRQOL. After controlling for socio-demographic factors, the results revealed that larger and more tree areas were positively correlated with children's HRQOL. In addition, those children living in areas with tree patches further apart from each other showed higher HRQOL. This research adds to the current multi-disciplinary area of research on environment-health relationships by investigating the roles of urban greeneries and linking their spatial structures with children's HRQOL. PMID:26771623

  19. "Kids for Trees": Student Projects in Real-Life Natural Resource Management.

    ERIC Educational Resources Information Center

    Chandler, Jim

    The "Kids for Trees" program described in this guidebook is a hands-on natural resource management experience where students raise trees from seedlings to harvest and manage other natural resources in a sustainable manner. Sections of the book include key concepts, getting started, needs of different kinds of trees, learning about potential…

  20. Formative Life Experiences and the Recruitment of Natural Resource Conservation Professionals

    ERIC Educational Resources Information Center

    Jackson, Marc

    2013-01-01

    Recruiting young people to serve as future leaders is a major concern for many organizations involved in natural resource conservation. One of the primary reasons for this concern is that youth are becoming less connected to the natural world because of the synergistic effects of urbanization, electronic media, and reduced opportunities to explore…

  1. Type 1 diabetes prevalence increasing globally and regionally: the role of natural selection and life expectancy at birth

    PubMed Central

    You, Wen-Peng; Henneberg, Maciej

    2016-01-01

    Objective Prevalence of type 1 diabetes (T1D) disease is increasing worldwide. We aim to test correlation of T1D prevalence to the reduced natural selection measured by Biological State Index (Ibs). Research design and methods Country-specific estimates of T1D prevalence, life expectancy, obesity prevalence rate, urbanization rates, per capita sugars consumption and per capita gross domestic product (GDP) were obtained. Ibs and country-specific longevity (e50) increase for each country were self-calculated. These data were then matched to T1D prevalence by country for our ecological study among 118 countries. Countries were also grouped to study the associations in different regions. SPSS V.22 was used for correlation analysis. Results Worldwide, both Ibs and life expectancy at birth (Ibs proxy) were significantly correlated to T1D prevalence in Pearson r (r=0.713, p<0.001 and r=0.722, p<0.001, respectively) and Spearman's r (r=0.724, p<0.001 and r=0.689, p<0.001, respectively). T1D prevalence was not correlated to longevity increase measured as life expectancy at 50 years old. T1D prevalence was significantly associated with Ibs (r=0.307, p<0.001) and newborn life expectancy (r=0.349, p<0.001) independent of per capita total sugar consumption, per capita GDP, urbanization and obesity prevalence in partial correlation. Globally, both life expectancy at birth and Ibs exponentially correlated to T1D prevalence. Pearson correlations generally existed in different country categorizations by geographic region, culture background and economic status. Conclusions Reduced natural selection may have contributed to the increasing T1D prevalence worldwide. T1D epidemiology study in total population may be the practical solution to identify the causes of increasing T1D prevalence. PMID:26977306

  2. The logic of comparative life history studies for estimating key parameters, with a focus on natural mortality rate

    USGS Publications Warehouse

    Hoenig, John M; Then, Amy Y.-H.; Babcock, Elizabeth A.; Hall, Norman G.; Hewitt, David A.; Hesp, Sybrand A.

    2016-01-01

    There are a number of key parameters in population dynamics that are difficult to estimate, such as natural mortality rate, intrinsic rate of population growth, and stock-recruitment relationships. Often, these parameters of a stock are, or can be, estimated indirectly on the basis of comparative life history studies. That is, the relationship between a difficult to estimate parameter and life history correlates is examined over a wide variety of species in order to develop predictive equations. The form of these equations may be derived from life history theory or simply be suggested by exploratory data analysis. Similarly, population characteristics such as potential yield can be estimated by making use of a relationship between the population parameter and bio-chemico–physical characteristics of the ecosystem. Surprisingly, little work has been done to evaluate how well these indirect estimators work and, in fact, there is little guidance on how to conduct comparative life history studies and how to evaluate them. We consider five issues arising in such studies: (i) the parameters of interest may be ill-defined idealizations of the real world, (ii) true values of the parameters are not known for any species, (iii) selecting data based on the quality of the estimates can introduce a host of problems, (iv) the estimates that are available for comparison constitute a non-random sample of species from an ill-defined population of species of interest, and (v) the hierarchical nature of the data (e.g. stocks within species within genera within families, etc., with multiple observations at each level) warrants consideration. We discuss how these issues can be handled and how they shape the kinds of questions that can be asked of a database of life history studies.

  3. The earliest Lunar Magma Ocean differentiation recorded in Fe isotopes

    NASA Astrophysics Data System (ADS)

    Wang, Kun; Jacobsen, Stein B.; Sedaghatpour, Fatemeh; Chen, Heng; Korotev, Randy L.

    2015-11-01

    Recent high-precision isotopic measurements show that the isotopic similarity of Earth and Moon is unique among all known planetary bodies in our Solar System. These observations provide fundamental constraints on the origin of Earth-Moon system, likely a catastrophic Giant Impact event. However, in contrast to the isotopic composition of many elements (e.g., O, Mg, Si, K, Ti, Cr, and W), the Fe isotopic compositions of all lunar samples are significantly different from those of the bulk silicate Earth. Such a global Fe isotopic difference between the Moon and Earth provides an important constraint on the lunar formation - such as the amount of Fe evaporation as a result of a Giant Impact origin of the Moon. Here, we show through high-precision Fe isotopic measurements of one of the oldest lunar rocks (4.51 ± 0.10 Gyr dunite 72 415), compared with Fe isotope results of other lunar samples from the Apollo program, and lunar meteorites, that the lunar dunite is enriched in light Fe isotopes, complementing the heavy Fe isotope enrichment in other lunar samples. Thus, the earliest olivine accumulation in the Lunar Magma Ocean may have been enriched in light Fe isotopes. This new observation allows the Fe isotopic composition of the bulk silicate Moon to be identical to that of the bulk silicate Earth, by balancing light Fe in the deep Moon with heavy Fe in the shallow Moon rather than the Moon having a heavier Fe isotope composition than Earth as a result of Giant Impact vaporization.

  4. Configurational approach to identifying the earliest hominin butchers.

    PubMed

    Domínguez-Rodrigo, Manuel; Pickering, Travis Rayne; Bunn, Henry T

    2010-12-01

    The announcement of two approximately 3.4-million-y-old purportedly butchered fossil bones from the Dikika paleoanthropological research area (Lower Awash Valley, Ethiopia) could profoundly alter our understanding of human evolution. Butchering damage on the Dikika bones would imply that tool-assisted meat-eating began approximately 800,000 y before previously thought, based on butchered bones from 2.6- to 2.5-million-y-old sites at the Ethiopian Gona and Bouri localities. Further, the only hominin currently known from Dikika at approximately 3.4 Ma is Australopithecus afarensis, a temporally and geographically widespread species unassociated previously with any archaeological evidence of butchering. Our taphonomic configurational approach to assess the claims of A. afarensis butchery at Dikika suggests the claims of unexpectedly early butchering at the site are not warranted. The Dikika research group focused its analysis on the morphology of the marks in question but failed to demonstrate, through recovery of similarly marked in situ fossils, the exact provenience of the published fossils, and failed to note occurrences of random striae on the cortices of the published fossils (incurred through incidental movement of the defleshed specimens across and/or within their abrasive encasing sediments). The occurrence of such random striae (sometimes called collectively "trampling" damage) on the two fossils provide the configurational context for rejection of the claimed butchery marks. The earliest best evidence for hominin butchery thus remains at 2.6 to 2.5 Ma, presumably associated with more derived species than A. afarensis. PMID:21078985

  5. Earliest Example of a Giant Monitor Lizard (Varanus, Varanidae, Squamata)

    PubMed Central

    Conrad, Jack L.; Balcarcel, Ana M.; Mehling, Carl M.

    2012-01-01

    Background Varanidae is a clade of tiny (<20 mm pre-caudal length [PCL]) to giant (>600 mm PCL) lizards first appearing in the Cretaceous. True monitor lizards (Varanus) are known from diagnostic remains beginning in the early Miocene (Varanus rusingensis), although extremely fragmentary remains have been suggested as indicating earlier Varanus. The paleobiogeographic history of Varanus and timing for origin of its gigantism remain uncertain. Methodology/Principal Findings A new Varanus from the Mytilini Formation (Turolian, Miocene) of Samos, Greece is described. The holotype consists of a partial skull roof, right side of a braincase, partial posterior mandible, fragment of clavicle, and parts of six vertebrae. A cladistic analysis including 83 taxa coded for 5733 molecular and 489 morphological characters (71 previously unincluded) demonstrates that the new fossil is a nested member of an otherwise exclusively East Asian Varanus clade. The new species is the earliest-known giant (>600 mm PCL) terrestrial lizard. Importantly, this species co-existed with a diverse continental mammalian fauna. Conclusions/Significance The new monitor is larger (longer) than 99% of known fossil and living lizards. Varanus includes, by far, the largest limbed squamates today. The only extant non-snake squamates that approach monitors in maximum size are the glass-snake Pseudopus and the worm-lizard Amphisbaena. Mosasauroids were larger, but exclusively marine, and occurred only during the Late Cretaceous. Large, extant, non-Varanus, lizards are limbless and/or largely isolated from mammalian competitors. By contrast, our new Varanus achieved gigantism in a continental environment populated by diverse eutherian mammal competitors. PMID:22900001

  6. Kant and the nature of matter: Mechanics, chemistry, and the life sciences.

    PubMed

    Gaukroger, Stephen

    2016-08-01

    Kant believed that the ultimate processes that regulate the behavior of material bodies can be characterized exclusively in terms of mechanics. In 1790, turning his attention to the life sciences, he raised a potential problem for his mechanically-based account, namely that many of the operations described in the life sciences seemed to operate teleologically. He argued that the life sciences do indeed require us to think in teleological terms, but that this is a fact about us, not about the processes themselves. Nevertheless, even were we to concede his account of the life sciences, this would not secure the credentials of mechanics as a general theory of matter. Hardly any material properties studied in the second half of the eighteenth century were, or could have been, conceived in mechanical terms. Kant's concern with teleology is tangential to the problems facing a general matter theory grounded in mechanics, for the most pressing issues have nothing to do with teleology. They derive rather from a lack of any connection between mechanical forces and material properties. This is evident in chemistry, which Kant dismisses as being unscientific on the grounds that it cannot be formulated in mechanical terms. PMID:27474191

  7. The nature and dynamics of world religions: a life-history approach

    PubMed Central

    Baumard, Nicolas; Chevallier, Coralie

    2015-01-01

    In contrast with tribal and archaic religions, world religions are characterized by a unique emphasis on extended prosociality, restricted sociosexuality, delayed gratification and the belief that these specific behaviours are sanctioned by some kind of supernatural justice. Here, we draw on recent advances in life history theory to explain this pattern of seemingly unrelated features. Life history theory examines how organisms adaptively allocate resources in the face of trade-offs between different life-goals (e.g. growth versus reproduction, exploitation versus exploration). In particular, recent studies have shown that individuals, including humans, adjust their life strategy to the environment through phenotypic plasticity: in a harsh environment, organisms tend to adopt a ‘fast' strategy, pursuing smaller but more certain benefits, while in more affluent environments, organisms tend to develop a ‘slow' strategy, aiming for larger but less certain benefits. Reviewing a range of recent research, we show that world religions are associated with a form of ‘slow' strategy. This framework explains both the promotion of ‘slow' behaviours such as altruism, self-regulation and monogamy in modern world religions, and the condemnation of ‘fast' behaviours such as selfishness, conspicuous sexuality and materialism. This ecological approach also explains the diffusion pattern of world religions: why they emerged late in human history (500–300 BCE), why they are currently in decline in the most affluent societies and why they persist in some places despite this overall decline. PMID:26511055

  8. The Encounter With Life-Threatening Danger: Its Nature and Impact.

    ERIC Educational Resources Information Center

    Noyes, Russell, Jr.

    1981-01-01

    A factor analysis of questionnaire responses from (N=189) victims of life-threatening accidents identified three dimensions of the altered state of consciousness produced by dangerous circumstances. These dimensions, included depersonalization, hyperalertness, and mystical consciousness, appeared meaningful in terms of the endangered personality's…

  9. The nature and dynamics of world religions: a life-history approach.

    PubMed

    Baumard, Nicolas; Chevallier, Coralie

    2015-11-01

    In contrast with tribal and archaic religions, world religions are characterized by a unique emphasis on extended prosociality, restricted sociosexuality, delayed gratification and the belief that these specific behaviours are sanctioned by some kind of supernatural justice. Here, we draw on recent advances in life history theory to explain this pattern of seemingly unrelated features. Life history theory examines how organisms adaptively allocate resources in the face of trade-offs between different life-goals (e.g. growth versus reproduction, exploitation versus exploration). In particular, recent studies have shown that individuals, including humans, adjust their life strategy to the environment through phenotypic plasticity: in a harsh environment, organisms tend to adopt a 'fast' strategy, pursuing smaller but more certain benefits, while in more affluent environments, organisms tend to develop a 'slow' strategy, aiming for larger but less certain benefits. Reviewing a range of recent research, we show that world religions are associated with a form of 'slow' strategy. This framework explains both the promotion of 'slow' behaviours such as altruism, self-regulation and monogamy in modern world religions, and the condemnation of 'fast' behaviours such as selfishness, conspicuous sexuality and materialism. This ecological approach also explains the diffusion pattern of world religions: why they emerged late in human history (500-300 BCE), why they are currently in decline in the most affluent societies and why they persist in some places despite this overall decline. PMID:26511055

  10. Allocation Games: Addressing the Ill-Posed Nature of Allocation in Life-Cycle Inventories.

    PubMed

    Hanes, Rebecca J; Cruze, Nathan B; Goel, Prem K; Bakshi, Bhavik R

    2015-07-01

    Allocation is required when a life cycle contains multi-functional processes. One approach to allocation is to partition the embodied resources in proportion to a criterion, such as product mass or cost. Many practitioners apply multiple partitioning criteria to avoid choosing one arbitrarily. However, life cycle results from different allocation methods frequently contradict each other, making it difficult or impossible for the practitioner to draw any meaningful conclusions from the study. Using the matrix notation for life-cycle inventory data, we show that an inventory that requires allocation leads to an ill-posed problem: an inventory based on allocation is one of an infinite number of inventories that are highly dependent upon allocation methods. This insight is applied to comparative life-cycle assessment (LCA), in which products with the same function but different life cycles are compared. Recently, there have been several studies that applied multiple allocation methods and found that different products were preferred under different methods. We develop the Comprehensive Allocation Investigation Strategy (CAIS) to examine any given inventory under all possible allocation decisions, enabling us to detect comparisons that are not robust to allocation, even when the comparison appears robust under conventional partitioning methods. While CAIS does not solve the ill-posed problem, it provides a systematic way to parametrize and examine the effects of partitioning allocation. The practical usefulness of this approach is demonstrated with two case studies. The first compares ethanol produced from corn stover hydrolysis, corn stover gasification, and corn grain fermentation. This comparison was not robust to allocation. The second case study compares 1,3-propanediol (PDO) produced from fossil fuels and from biomass, which was found to be a robust comparison. PMID:26061700

  11. Evolution and maintenance of haploid-diploid life cycles in natural populations: The case of the marine brown alga Ectocarpus.

    PubMed

    Couceiro, Lucía; Le Gac, Mickael; Hunsperger, Heather M; Mauger, Stéphane; Destombe, Christophe; Cock, J Mark; Ahmed, Sophia; Coelho, Susana M; Valero, Myriam; Peters, Akira F

    2015-07-01

    The evolutionary stability of haploid-diploid life cycles is still controversial. Mathematical models indicate that niche differences between ploidy phases may be a necessary condition for the evolution and maintenance of these life cycles. Nevertheless, experimental support for this prediction remains elusive. In the present work, we explored this hypothesis in natural populations of the brown alga Ectocarpus. Consistent with the life cycle described in culture, Ectocarpus crouaniorum in NW France and E. siliculosus in SW Italy exhibited an alternation between haploid gametophytes and diploid sporophytes. Our field data invalidated, however, the long-standing view of an isomorphic alternation of generations. Gametophytes and sporophytes displayed marked differences in size and, conforming to theoretical predictions, occupied different spatiotemporal niches. Gametophytes were found almost exclusively on the alga Scytosiphon lomentaria during spring whereas sporophytes were present year-round on abiotic substrata. Paradoxically, E. siliculosus in NW France exhibited similar habitat usage despite the absence of alternation of ploidy phases. Diploid sporophytes grew both epilithically and epiphytically, and this mainly asexual population gained the same ecological advantage postulated for haploid-diploid populations. Consequently, an ecological interpretation of the niche differences between haploid and diploid individuals does not seem to satisfactorily explain the evolution of the Ectocarpus life cycle. PMID:26096000

  12. [Life risk and nature of SAMU: users' perspectives and implications for nursing].

    PubMed

    Veronese, Andréa Márian; de Oliveira, Dora Lúcia Leidens Corrêa; Nast, Karoline

    2012-12-01

    The article is part of a qualitative study analisys developed in 2009 aiming at investigating the demand of emergency calls to the Emergency Mobile Attendance Service/Porto Alegre (SAMU) that classifies it as non-pertinent. The information was gathered from 16 semi-structured interviews with the subjects of that demand by utilizing as a methodological guideline the Grounded Theory. The article approaches the content of the sub-category "Entering into conflict with SAMU regulation in the evaluation of life-threatening", by focusing the divergences between the regulation and the users' perception about the operation of the service and the meaning of "life-threatening", factors implied in the construction of the non-pertinent demand. The importance of Nursing within this scenery is in its competence to perform education actions about first aid and to participate in projects among sectors which are able to intervene in situations that generate vulnerability. PMID:23596928

  13. Earliest Mexican Turkeys (Meleagris gallopavo) in the Maya Region: Implications for Pre-Hispanic Animal Trade and the Timing of Turkey Domestication

    PubMed Central

    Thornton, Erin Kennedy; Emery, Kitty F.; Steadman, David W.; Speller, Camilla; Matheny, Ray; Yang, Dongya

    2012-01-01

    Late Preclassic (300 BC–AD 100) turkey remains identified at the archaeological site of El Mirador (Petén, Guatemala) represent the earliest evidence of the Mexican turkey (Meleagris gallopavo) in the ancient Maya world. Archaeological, zooarchaeological, and ancient DNA evidence combine to confirm the identification and context. The natural pre-Hispanic range of the Mexican turkey does not extend south of central Mexico, making the species non-local to the Maya area where another species, the ocellated turkey (Meleagris ocellata), is indigenous. Prior to this discovery, the earliest evidence of M. gallopavo in the Maya area dated to approximately one thousand years later. The El Mirador specimens therefore represent previously unrecorded Preclassic exchange of animals from northern Mesoamerica to the Maya cultural region. As the earliest evidence of M. gallopavo found outside its natural geographic range, the El Mirador turkeys also represent the earliest indirect evidence for Mesoamerican turkey rearing or domestication. The presence of male, female and sub-adult turkeys, and reduced flight morphology further suggests that the El Mirador turkeys were raised in captivity. This supports an argument for the origins of turkey husbandry or at least captive rearing in the Preclassic. PMID:22905156

  14. Nature and nurture of the interplay between personality traits and major life goals.

    PubMed

    Bleidorn, Wiebke; Kandler, Christian; Hülsheger, Ute R; Riemann, Rainer; Angleitner, Alois; Spinath, Frank M

    2010-08-01

    Modern personality theories differ in their assumptions about the structure and etiology of the interplay between personality traits and motivational constructs. The present study examined the genetic and environmental sources of the interplay between the Big Five and major life goals concurrently and across time in order to provide a more decisive evaluation of the conflicting assumptions stated in the five-factor theory as opposed to socioanalytic conceptions. Traits and goals were assessed twice across a 5-year period in a sample of 217 identical and 112 fraternal twin pairs from the Bielefeld Longitudinal Study of Adult Twins. About 30% of the variance in agency and communion life goals was genetic; the remaining variance was due to nonshared environmental effects, whereas shared environmental effects were negligible. Both heritable and environmental variance in goals could partly be accounted for by genetic and nonshared environmental effects on personality traits. Across time, we revealed reciprocal genetic and environmental effects between traits and life goals. In sum, our findings yield partial support for both of the 2 competing personality theories, suggesting a readjusted picture of the interplay between traits and goals. PMID:20658849

  15. When everyday life becomes a storm on the horizon: families' experiences of good mental health while hiking in nature.

    PubMed

    Baklien, Børge; Ytterhus, Borgunn; Bongaardt, Rob

    2016-01-01

    Hiking in nature is often presented as a yearning for lost harmony premised on an alleged divide between nature as authentically healthy and society as polluted. This paper's aim is to question this strict divide and the strong belief in nature as having an innate health-providing effect, the biophilia hypothesis, by examining what Norwegian families with young children experience when walking in the forest. Twenty-four conversations with families during a hiking trip in the forest were recorded, and the data were analysed with Giorgi's descriptive phenomenological research method. The paper introduces the general descriptive meaning structure of the phenomenon 'family-hiking with young children'. It shows that a hiking trip clears space for the family in their everyday lives which is largely dominated by relations with non-family members at both work and leisure. The families experience that they actively generate a different existence with a sense of here-and-now presences that can strengthen core family relations and also provide the opportunity to pass down experiences that can be recollected and realized by future generations. This experience is complex and constituted by social practices, which indicate that the biophilia hypothesis seems to be an insufficient explanation of why families go hiking in nature. Nature rather represents a peaceful background that allows for the perpetuation of the family as a social institution and the recreation of cohesion in everyday life. PMID:26208677

  16. Natural humic substances effects on the life history traits of Latonopsis australis SARS (1888) (Cladocera--Crustacea).

    PubMed

    de Carvalho-Pereira, Ticiana Soares de Andrade; Santos, Thirza de Santana; Pestana, Edilene M S; Souza, Fábio Neves; Lage, Vivian Marina Gomes Barbosa; Nunesmaia, Bárbara Janaína Bezerra; Sena, Palloma Thaís Souza; Mariano-Neto, Eduardo; da Silva, Eduardo Mendes

    2015-02-01

    Cultivation medium is one of the first aspects to be considered in zooplankton laboratory cultivation. The use of artificial media does not concern to reproduce natural conditions to the cultivations, which may be achieved by using natural organic compounds like humic substances (HS). This study aimed to evaluate the effects of a concentrate of dissolved organic carbon (DOC) from the Negro River (NR(1)) and an extraction of humic acids (HA) from humus produced by Eisenia andrei on the life history traits of laboratory-based Latonopsis australis SARS (1888). A cohort life table approach was used to provide information about the effectiveness of NR and HA as supplements for the artificial cultivation of L. australis. Additionally, we seek to observe a maximization of L. australis artificial cultivation fitness by expanding the range of HS concentrations. The first experiment demonstrated that the females of L. australis reared under NR10 (mgDOCL(-1)) may have experienced an acceleration of the population life cycle, as the females have proportionally reproduced more and lived shorter than controls. By contrast, the use of the HA did not improve life history traits considered. The expansion of the concentration range (5, 10, 20 and 50 mgDOCL(-1)) corroborated the patterns observed on the first assay. Results for the fitness estimates combined with shorter lifespans than controls demonstrated trade-offs between reproductive output and female longevity reared under NR conditions, with NR20 been suggested as the best L. australis cultivation medium. This response might be associated with hormone-like effects. PMID:25025739

  17. LIFE CYCLE DESIGN FRAMEWORK AND DEMONSTRATION PROJECTS PROFILES OF AT&T AND ALLIED SIGNAL

    EPA Science Inventory

    Life cycle design seeks to minimize the environmental burden associated with a product life cycle from raw materials acquisition through manufacturing, use, and end-of-life management. ife cycle design emphasizes integrating environmental requirements into the earliest phases of ...

  18. Giant cladoxylopsid trees resolve the enigma of the Earth's earliest forest stumps at Gilboa.

    PubMed

    Stein, William E; Mannolini, Frank; Hernick, Linda VanAller; Landing, Ed; Berry, Christopher M

    2007-04-19

    The evolution of trees of modern size growing together in forests fundamentally changed terrestrial ecosystems. The oldest trees are often thought to be of latest Devonian age (about 380-360 Myr old) as indicated by the widespread occurrence of Archaeopteris (Progymnospermopsida). Late Middle Devonian fossil tree stumps, rooted and still in life position, discovered in the 1870s from Gilboa, New York, and later named Eospermatopteris, are widely cited as evidence of the Earth's 'oldest forest'. However, their affinities and significance have proved to be elusive because the aerial portion of the plant has been unknown until now. Here we report spectacular specimens from Schoharie County, New York, showing an intact crown belonging to the cladoxylopsid Wattieza (Pseudosporochnales) and its attachment to Eospermatopteris trunk and base. This evidence allows the reconstruction of a tall (at least 8 m), tree-fern-like plant with a trunk bearing large branches in longitudinal ranks. The branches were probably abscised as frond-like modules. Lower portions of the trunk show longitudinal carbonaceous strands typical of Eospermatopteris, and a flat bottom with many small anchoring roots. These specimens provide new insight into Earth's earliest trees and forest ecosystems. The tree-fern-like morphology described here is the oldest example so far of an evolutionarily recurrent arborescent body plan within vascular plants. Given their modular construction, these plants probably produced abundant litter, indicating the potential for significant terrestrial carbon accumulation and a detritus-based arthropod fauna by the Middle Devonian period. PMID:17443185

  19. Rise of the Earliest Tetrapods: An Early Devonian Origin from Marine Environment

    PubMed Central

    George, David; Blieck, Alain

    2011-01-01

    Tetrapod fossil tracks are known from the Middle Devonian (Eifelian at ca. 397 million years ago - MYA), and their earliest bony remains from the Upper Devonian (Frasnian at 375–385 MYA). Tetrapods are now generally considered to have colonized land during the Carboniferous (i.e., after 359 MYA), which is considered to be one of the major events in the history of life. Our analysis on tetrapod evolution was performed using molecular data consisting of 13 proteins from 17 species and different paleontological data. The analysis on the molecular data was performed with the program TreeSAAP and the results were analyzed to see if they had implications on the paleontological data collected. The results have shown that tetrapods evolved from marine environments during times of higher oxygen levels. The change in environmental conditions played a major role in their evolution. According to our analysis this evolution occurred at about 397–416 MYA during the Early Devonian unlike previously thought. This idea is supported by various environmental factors such as sea levels and oxygen rate, and biotic factors such as biodiversity of arthropods and coral reefs. The molecular data also strongly supports lungfish as tetrapod's closest living relative. PMID:21779385

  20. Life-history evolution and elevated natural mortality in a population of Atlantic cod (Gadus morhua)

    PubMed Central

    Swain, Douglas P

    2011-01-01

    Fisheries-induced evolution has been hypothesized to delay the recovery of collapsed fish stocks through effects on their productivity. The cod stock in the southern Gulf of St. Lawrence (SGSL) collapsed in the early 1990s and has shown no recovery since then, due mainly to high natural mortality of adult cod. Age and size at maturation of SGSL cod decreased sharply over time in cohorts produced in the 1950s and 1960s, likely reflecting an evolutionary response to intensified fishing, and have remained low since then, despite severe reductions in fishing mortality over the past 15 years. A predicted consequence of early maturation is increased natural mortality due to higher costs to reproduction. Early maturation may be a cause of increases in natural mortality of SGSL cod in the 1970s but does not appear to be related to the much larger increases since then. Instead, the current high natural mortality of SGSL cod appears to be primarily a cause, rather than a consequence, of the continued early maturation in this population, now replacing fishing mortality as the agent of selection favouring early maturity. This striking example of the failure to reverse fisheries-induced evolution by relaxing fishing pressure emphasizes the need for management strategies that minimize the chances of harvest-induced genetic change. PMID:25567950

  1. Long life catalytic membrane reactors for spontaneous conversion of natural gas to synthesis gas

    SciTech Connect

    Schwartz, M., White, J., Deych, S., Millard, J., Myers, M., Sammells, A.

    1997-10-01

    This program is focusing on the development of mixed ionic and electronic conducting materials based on the brown millerite structure for use in catalytic membrane reactors (CMRs). These CMRs are being evaluated for promoting the spontaneous and highly selective oxidative reforming of carbon dioxide / natural gas mixtures to synthesis gas.

  2. Effect of stress corrosion cracking on integrity and remaining life of natural gas pipelines

    SciTech Connect

    Jaske, C.E.; Beavers, J.A.; Harle, B.A.

    1996-08-01

    External stress-corrosion cracking of pipelines is a serious problem for the gas transmission industry. Longitudinal cracks initiate on the outside surface of the pipe and link up to form flaws that, in some cases, can lead to pipe rupture. This paper presents a model that quantifies the effect of stress-corrosion cracking on pipe failure stress. The model is an extension of those that have been developed for oil and gas pipelines and considers both flow-stress and fracture-toughness dependent failure modes. A methodology also is presented to calculate the remaining life of a pipeline containing flaws of known size.

  3. Environmental education as preparation people for life in conditions of global changes imbalanced Nature

    NASA Astrophysics Data System (ADS)

    Dabrowska, A. E.

    2013-12-01

    The Regional Teacher Training Centre in Skierniewice is one of 49 public, accredited institutions in Poland. It is responsible for organizing of support of schools, institutions, networks of teachers and school managers for cooperation and self education, organizing and conducting forms of in-service training, giving methodological councils and disseminating examples of good practice. I present one example of how Environmental Education has been imparted to school students and their teachers through outdoor activities as part of the learning process. An Environmental Education Program, 'On Bolimov Nature Preserve Trails' has been organized regularly since 2001. The Bolimov Nature Preserve is a protected area in central Poland, situated between two agglomerations: capital city Warsaw to the East and industrial city Lodz to the West. It was established to protect an unique ecosystem on the Rawka River banks from human activity and harmful external factors. Pine tree forests, small streams, wetlands, glades are another elements of the park scenery. Walks on the park's trails are a great opportunity to see unique species of flora (more than 40 protected species and many endangered species on verge of extinction) and fauna. For teachers and students the Bolimov Nature Preserve offers educational lessons and events. The main activity is participation of students and teachers in group walk along trails of the park using various tools of orientation: maps, compasses and GPS. Along the paths they learn recognition of forms of terrain, identification of living species (using flora&fauna guides, magnifying glasses), measuring components of weather (using weather atlases, thermometers, anemometers) as well as preparation of soil profile. A survey is conducted after each such program. A statistical analysis of the survey data reveals that each year more and more students representing all levels of education from primary to upper secondary levels and their teachers are involved

  4. The sounds of social life: a psychometric analysis of students' daily social environments and natural conversations.

    PubMed

    Mehl, Matthias R; Pennebaker, James W

    2003-04-01

    The natural conversations and social environments of 52 undergraduates were tracked across two 2-day periods separated by 4 weeks using a computerized tape recorder (the Electronically Activated Recorder [EAR]). The EAR was programmed to record 30-s snippets of ambient sounds approximately every 12 min during participants' waking hours. Students' social environments and use of language in their natural conversations were mapped in terms of base rates and temporal stability. The degree of cross-context consistency and between-speaker synchrony in language use was assessed. Students' social worlds as well as their everyday language were highly consistent across time and context. The study sheds light on a methodological blind spot--the sampling of naturalistic social information from an unobtrusive observer's perspective. PMID:12703653

  5. The onset of life in a natural submarine hydrothermal fractionation reactor

    NASA Astrophysics Data System (ADS)

    Russell, M. J.; Martin, W.

    There was a strong disequilibrium between the carbon dioxide in the early atmosphere and hydrothermal hydrogen. Such a disequilibrium tends to increase at lower temperatures but so do the kinetic barriers to reaction. Ignoring these kinetic barriers the strongest thermodynamic drive is to the production of methane as carbon dioxide reacts with hydrogen. But kinetic barriers prevent this reaction below 500C. In its stead Shock et al. (1998) demonstrate that metastable acetate is overwhelmingly the best represented carbon compound produced theoretically on the mixing of hydrothermal solution with seawater between 10 and 65C. The minor sticky by-product of this reaction, which involves other reactants, can be considered as evolving to protolife. Thus we argue that the organic building modules of life could be generated from the simplest entities within the hydrothermal mound. And the main waste products would be acetate and water: {407H2+10NH3+HS-hydroth'l +{210CO2+H2PO4- + [Fe,Ni,Co]2+ocean → gC70H129O65N10P(Fe,Ni,Co)Sprotolife+{70H3C.COOH+219H2Owaste We suggest that protolife emerged at ˜ 40C where chemical gradients were steep in a hydrothermal mound which developed where alkaline waters seeped into the Hadean ocean. The mound acted as a fractionation reactor. Reactions were catalysed by such sulfide clusters as would produce greigite (NiFe5S8) in membranes also composed of sulfides (Martin and Russell 2003). A greigite cluster was the precursor to the active sites of carbon monoxide dehydrogenase (NiFe4S5) and acetyl coenzyme-A synthase ([Fe4S4]cysNicys2Ni) (Svetlitchnyi et al. 2004). Activation energy was supplied by reaction between photolytic ferric iron and H2 across the membranes comprising FeS compartments at the mound's surface. Small quantities of amino acids, metal-bearing clusters (Milner-White and Russell 2004), and eventually RNA precursors, self-organised to become involved in the more efficient generation of acetate waste, a thermodynamic

  6. Fate and persistence of glutaraldehyde and retention lagoon diversity of life at a natural gas storage facility

    SciTech Connect

    Derr, R.M.; Morris, E.A. III; Pope, D.H.

    1995-12-31

    In view of increasingly stringent environmental regulations concerning Produced water disposal, the natural gas industry needs to approximate the maximum amount of biocide which can be applied downhole and not adversely impact the local biology in retention lagoons receiving produced waters. Biocide treatment data from a microbially sour aquifer-storage natural gas facility, archived by the operations personnel, were incorporated into a study sponsored by the Gas Research Institute (GRI), Chicago, Illinois along with additional data from focused field sampling. The sandy assessed the persistence and fate of glutaraldehyde and its possible effects on diversity of life in the produced water system and outfall areas which receive the lagoon discharge under a National Pollution Discharge Elimination System (NPDES) permit. In this study, a mathematical model was constructed that incorporated experimentally-determined glutaraldehyde persistence, wellhead Outaraldehyde residuals, rates of water production, and lagoon specifications. The model was used to calculate the levels of glutaraldehyde in the lagoons as a function of time, based on the amount of glutaraldehyde applied downhole. The modeled results were used to assess the potential impacts of various levels of downhole treatment using glutaraldehyde and confirmed that the current treatment regime provided little potential for adverse environmental effects in the retention lagoons or the lagoon outfall areas. Chemical and biological sampling and diversity of life analyses were performed in the retention lagoon system and outfall areas to further test for environmental impacts relating to biocide use; no evidence of adverse effects was found.

  7. Shelf Life and Quality Study of Minced Tilapia with Nori and Hijiki Seaweeds as Natural Additives

    PubMed Central

    Ribeiro, Ingridy Simone; Shirahigue, Ligianne Din; Ferraz de Arruda Sucasas, Lia; Anbe, Lika; da Cruz, Pedro Gomes; Gallo, Cláudio Rosa; Carpes, Solange Teresinha; Marques, Marcos José; Oetterer, Marília

    2014-01-01

    The extraction of mechanically separated meat has emerged as an attractive process. However, it increases the incorporation of oxygen and, consequently, of flavors due to rancidity. Thus, preservatives must be added. The objective of this study was to evaluate the shelf life of minced tilapia to replace synthetic preservatives with Hijiki and Nori seaweeds extracts. The application of the extracts had no effect on the chemical composition of the minced tilapia. The seaweed extracts had inhibitory effect on total volatile base nitrogen. The minced tilapia complied with the microbiological standard set by Brazilin law. The panelists detected no differences in the rancid aroma and only minor differences were detected in the color of the products. It can be concluded that the minced tilapia with added seaweed extracts were within quality standards during frozen storage. PMID:25478593

  8. Shelf life and quality study of minced tilapia with Nori and Hijiki seaweeds as natural additives.

    PubMed

    Ribeiro, Ingridy Simone; Shirahigue, Ligianne Din; Ferraz de Arruda Sucasas, Lia; Anbe, Lika; da Cruz, Pedro Gomes; Gallo, Cláudio Rosa; Carpes, Solange Teresinha; Marques, Marcos José; Oetterer, Marília

    2014-01-01

    The extraction of mechanically separated meat has emerged as an attractive process. However, it increases the incorporation of oxygen and, consequently, of flavors due to rancidity. Thus, preservatives must be added. The objective of this study was to evaluate the shelf life of minced tilapia to replace synthetic preservatives with Hijiki and Nori seaweeds extracts. The application of the extracts had no effect on the chemical composition of the minced tilapia. The seaweed extracts had inhibitory effect on total volatile base nitrogen. The minced tilapia complied with the microbiological standard set by Brazilin law. The panelists detected no differences in the rancid aroma and only minor differences were detected in the color of the products. It can be concluded that the minced tilapia with added seaweed extracts were within quality standards during frozen storage. PMID:25478593

  9. The Search for Life on Mars

    NASA Technical Reports Server (NTRS)

    McKay, Christopher P.

    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. The Mars meteorites also suggest that early Mars was wet with conditions suitable for organic material. 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. time frame. 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.

  10. Munazza's story: Understanding science teaching and conceptions of the nature of science in Pakistan through a life history study

    NASA Astrophysics Data System (ADS)

    Halai, Nelofer

    In this study I have described and tried to comprehend how a female science teacher understands her practice. Additionally, I have developed some understanding of her understanding of the nature of science. While teaching science, a teacher projects messages about the nature of science that can be captured by observations and interviews. Furthermore, the manner is which a teacher conceptualizes science for teaching, at least in part, depends on personal life experiences. Hence, I have used the life history method to understand Munazza's practice. Munazza is a young female science teacher working in a private, co-educational school for children from middle income families in Karachi, Pakistan. Her stories are central to the study, and I have represented them using a number of narrative devices. I have woven in my own stories too, to illustrate my perspective as a researcher. The data includes 13 life history interviews and many informal conversations with Munazza, observations of science teaching in classes seven and eight, and interviews with other science teachers and administrative staff of the school. Munazza's personal biography and experiences of school and undergraduate courses has influenced the way she teaches. It has also influenced the way she does not teach. She was not inspired by her science teachers, so she has tried not to teach the way she was taught science. Contextual factors, her conception of preparation for teaching as preparation for subject content and the tension that she faces in balancing care and control in her classroom are some factors that influence her teaching. Munazza believes that science is a stable, superior and value-free way of knowing. In trying to understand the natural world, observations come first, which give reliable information about the world leading inductively to a "theory". Hence, she relies a great deal on demonstrations in the class where students "see" for themselves and abstract the scientific concept from the

  11. Calculation of the Phenix end-of-life test in natural circulation with the CATHARE code

    SciTech Connect

    Maas, L.; Cocheme, F.

    2012-07-01

    The Inst. of Radiological Protection and Nuclear Safety (IRSN) acts as technical support to French public authorities. As such, IRSN is in charge of safety assessment of operating and under construction reactors, as well as future projects. In this framework, one current objective of IRSN is to evaluate the ability and accuracy of numerical tools to foresee consequences of accidents. One of the advantages pointed up for fast reactors cooled by heavy liquid metal is the possibility of decay heat removal based on natural convection. The promotion of this passive cooling mode in future safety demonstrations will involve the use of adapted and validated numerical codes. After the final shutdown of the Phenix sodium cooled fast reactor in 2009, a set of tests covering different areas was conducted for code validation, including a natural circulation test in the primary circuit. Experimental data were issued by CEA to organize a benchmark exercise in the frame of an IAEA Coordinated Research Project (CRP), with the objective to assess the system-codes capability in simulating the thermal-hydraulics behavior of sodium cooled fast reactors in such accidental conditions. IRSN participated to this benchmark with the CATHARE code. This code, co-developed by CEA, EDF, AREVA and IRSN and widely used for PWR safety studies, was recently extended for sodium applications. This paper presents the CATHARE modeling of the Phenix primary circuit and the results obtained. A relatively good agreement was found with available measurements considering the experimental uncertainties. This work stressed the local aspects of phenomena occurring during the natural convection establishment and the limits of a 0D/1D approach. (authors)

  12. Bed bugs, their blood sources and life history parameters: a comparison of artificial and natural feeding.

    PubMed

    Aak, A; Rukke, B A

    2014-03-01

    A blood-feeding system that utilizes a small amount of whole heparinized human blood in parafilm bags is described in detail, and similarities and differences between artificially fed and naturally rodent-fed bed bugs (Hemiptera: Cimicidae) are discussed. Blood with high levels of heparin (10%) was unsuitable for artificial colony rearing, whereas bed bugs fed on 1% heparinized blood and those that naturally ingested rat blood completed their lifecycle with similar stage structures over time, with no significant differences in mortality. No differences in feeding efficiency or fertility were found in a direct comparison of bed bugs maintained under each of these two treatments, but analysis of the full lifecycle revealed that artificially fed bed bugs became significantly smaller and laid fewer eggs than rodent-fed bed bugs. The level of membrane stretching regulated the number of bed bugs that fed. When the membrane was stretched to twice its length and width, 96% of bed bugs successfully fed through the parafilm. Whole heparinized blood that was stored at 6 °C for ≥ 14 days failed to retain its nutritional value and the amount of blood consumed and number of consecutive moults were significantly reduced. PMID:23692154

  13. Bioorganic Chemistry. A Natural Reunion of the Physical and Life Sciences

    PubMed Central

    Poulter, C. Dale

    2009-01-01

    Organic substances were conceived as those found in living organisms. Although the definition was soon broadened to include all carbon-containing compounds, naturally occurring molecules have always held a special fascination for organic chemists. From these beginnings, molecules from nature were indespensible tools as generations of organic chemists developed new techniques for determining structures, analyzed the mechanisms of reactions, explored the effects conformation and stereochemistry on reactions, and found challenging new targets to synthesize. Only recently have organic chemists harnessed the powerful techniques of organic chemistry to study the functions of organic molecules in their biological hosts, the enzymes that synthesize molecules and the complex processes that occur in a cell. In this Perspective, I present a personal account my entrée into bioorganic chemistry as a physical organic chemist and subsequent work to understand the chemical mechanisms of enzyme-catalyzed reactions, to develop techniques to identify and assign hydrogen bonds in tRNAs through NMR studies with isotopically labeled molecules, and to study how structure determines function in biosynthetic enzymes with proteins obtained by genetic engineering. PMID:19323569

  14. Object recognition in congruent and incongruent natural scenes: a life-span study.

    PubMed

    Rémy, F; Saint-Aubert, L; Bacon-Macé, N; Vayssière, N; Barbeau, E; Fabre-Thorpe, M

    2013-10-18

    Efficient processing of our complex visual environment is essential and many daily visual tasks rely on accurate and fast object recognition. It is therefore important to evaluate how object recognition performance evolves during the course of adulthood. Surprisingly, this ability has not yet been investigated in the aged population, although several neuroimaging studies have reported altered activity in high-level visual ventral regions when elderly subjects process natural stimuli. In the present study, color photographs of various objects embedded in contextual scenes were used to assess object categorization performance in 97 participants aged from 20 to 91. Objects were either animals or pieces of furniture, embedded in either congruent or incongruent contexts. In every age group, subjects showed reduced categorization performance, both in terms of accuracy and speed, when objects were seen in incongruent vs. congruent contexts. In subjects over 60 years old, object categorization was greatly slowed down when compared to young and middle-aged subjects. Moreover, subjects over 75 years old evidenced a significant decrease in categorization accuracy when objects were seen in incongruent contexts. This indicates that incongruence of the scene may be particularly disturbing in late adulthood, therefore impairing object recognition. Our results suggest that daily visual processing of complex natural environments may be less efficient with age, which might impact performance in everyday visual tasks. PMID:23891714

  15. The earliest history of the deuterostomes: the importance of the Chengjiang Fossil-Lagerstätte

    PubMed Central

    Shu, D.-G.; Conway Morris, S.; Zhang, Z.-F.; Han, J.

    2010-01-01

    While the broad framework of deuterostome evolution is now clear, the remarkable diversity of extant forms within this group has rendered the nature of the ancestral types problematic: what, for example, does the common ancestor of a sea urchin and lamprey actually look like? The answer to such questions can be addressed on the basis of remarkably well-preserved fossils from Cambrian Lagerstätten, not least the celebrated Chengjiang Lagerstätte (Yunnan, China). This deposit is particularly important because of its rich diversity of deuterostomes. These include some of the earliest known representatives, among which are the first vertebrates, as well as more enigmatic groups, notably the vetulicolians and yunnanozoans. The latter groups, in particular, have been the subject of some radical divergences in opinion as to their exact phylogenetic placements. Here, we both review the known diversity of Chengjiang deuterostomes and in particular argue that the vetulicolians and yunnanozoans represent very primitive deuterostomes. Moreover, in the latter case we present new data to indicate that the yunnanozoans are unlikely to be any sort of chordate. PMID:19439437

  16. Cranial Bosses of Choerosaurus dejageri (Therapsida, Therocephalia): Earliest Evidence of Cranial Display Structures in Eutheriodonts

    PubMed Central

    Benoit, Julien; Manger, Paul R.; Fernandez, Vincent; Rubidge, Bruce S.

    2016-01-01

    Choerosaurus dejageri, a non-mammalian eutheriodont therapsid from the South African late Permian (~259 Ma), has conspicuous hemispheric cranial bosses on the maxilla and the mandible. These bosses, the earliest of this nature in a eutheriodont, potentially make C. dejageri a key species for understanding the evolutionary origins of sexually selective behaviours (intraspecific competition, ritualized sexual and intimidation displays) associated with cranial outgrowths at the root of the clade that eventually led to extant mammals. Comparison with the tapinocephalid dinocephalian Moschops capensis, a therapsid in which head butting is strongly supported, shows that the delicate structure of the cranial bosses and the gracile structure of the skull of Choerosaurus would be more suitable for display and low energy combat than vigorous head butting. Thus, despite the fact that Choerosaurus is represented by only one skull (which makes it impossible to address the question of sexual dimorphism), its cranial bosses are better interpreted as structures involved in intraspecific selection, i.e. low-energy fighting or display. Display structures, such as enlarged canines and cranial bosses, are widespread among basal therapsid clades and are also present in the putative basal therapsid Tetraceratops insignis. This suggests that sexual selection may have played a more important role in the distant origin and evolution of mammals earlier than previously thought. Sexual selection may explain the subsequent independent evolution of cranial outgrowths and pachyostosis in different therapsid lineages (Biarmosuchia, Dinocephalia, Gorgonopsia and Dicynodontia). PMID:27548428

  17. Cranial Bosses of Choerosaurus dejageri (Therapsida, Therocephalia): Earliest Evidence of Cranial Display Structures in Eutheriodonts.

    PubMed

    Benoit, Julien; Manger, Paul R; Fernandez, Vincent; Rubidge, Bruce S

    2016-01-01

    Choerosaurus dejageri, a non-mammalian eutheriodont therapsid from the South African late Permian (~259 Ma), has conspicuous hemispheric cranial bosses on the maxilla and the mandible. These bosses, the earliest of this nature in a eutheriodont, potentially make C. dejageri a key species for understanding the evolutionary origins of sexually selective behaviours (intraspecific competition, ritualized sexual and intimidation displays) associated with cranial outgrowths at the root of the clade that eventually led to extant mammals. Comparison with the tapinocephalid dinocephalian Moschops capensis, a therapsid in which head butting is strongly supported, shows that the delicate structure of the cranial bosses and the gracile structure of the skull of Choerosaurus would be more suitable for display and low energy combat than vigorous head butting. Thus, despite the fact that Choerosaurus is represented by only one skull (which makes it impossible to address the question of sexual dimorphism), its cranial bosses are better interpreted as structures involved in intraspecific selection, i.e. low-energy fighting or display. Display structures, such as enlarged canines and cranial bosses, are widespread among basal therapsid clades and are also present in the putative basal therapsid Tetraceratops insignis. This suggests that sexual selection may have played a more important role in the distant origin and evolution of mammals earlier than previously thought. Sexual selection may explain the subsequent independent evolution of cranial outgrowths and pachyostosis in different therapsid lineages (Biarmosuchia, Dinocephalia, Gorgonopsia and Dicynodontia). PMID:27548428

  18. Real-life assessment of the multidimensional nature of dyspnoea in COPD outpatients.

    PubMed

    Morélot-Panzini, Capucine; Gilet, Hélène; Aguilaniu, Bernard; Devillier, Philippe; Didier, Alain; Perez, Thierry; Pignier, Christophe; Arnould, Benoit; Similowski, Thomas

    2016-06-01

    Dyspnoea is a prominent symptom of chronic obstructive pulmonary disease (COPD). Recent multidimensional dyspnoea questionnaires like the Multidimensional Dyspnea Profile (MDP) individualise the sensory and affective dimensions of dyspnoea. We tested the MDP in COPD outpatients based on the hypothesis that the importance of the affective dimension of dyspnoea would vary according to clinical characteristics.A multicentre, prospective, observational, real-life study was conducted in 276 patients. MDP data were compared across various categories of patients (modified Medical Research Council (mMRC) dyspnoea score, COPD Assessment Test (CAT) score, Global Initiative for Chronic Obstructive Lung Disease (GOLD) airflow obstruction categories, GOLD "ABCD" categories, and Hospital Anxiety and Depression Scale (HADS)). Univariate and multivariate regressions were conducted to explore factors influencing the affective dimension of dyspnoea. Cluster analysis was conducted to create homogeneous patient profiles.The MDP identified a more marked affective dimension of dyspnoea with more severe mMRC, CAT, 12-item Short-Form Health Survey mental component, airflow obstruction and HADS. Multivariate analysis identified airflow obstruction, depressive symptoms and physical activity as determinants of the affective dimension of dyspnoea. Patients clustered into an "elderly, ex-smoker, severe disease, no rehabilitation" group exhibited the most marked affective dimension of dyspnoea.An affective/emotional dimension of dyspnoea can be identified in routine clinical practice. It can contribute to the phenotypic description of patients. Studies are needed to determine whether targeted therapeutic interventions can be designed and whether they are useful. PMID:27076585

  19. Natural resilience in Arctic charr Salvelinus alpinus: life history, spatial and dietary alterations along gradients of interspecific interactions.

    PubMed

    Hammar, J

    2014-07-01

    The Arctic charr Salvelinus alpinus species complex has been shown to be exceptionally vulnerable to rapid abiotic and biotic changes. Salvelinus alpinus, however, inhabit environmental extremes ranging from lakes and rivers in the High Arctic to deep multi-fish species lakes far outside the polar region. Long-term responses to post-glacial environmental variations and successively increased interspecific interactions reveal an essential degree of natural ecological resilience and phenotypic flexibility. Case studies in Scandinavia and Newfoundland illustrate the alternate trophic roles of S. alpinus, and its flexible niche use and life-history changes in order to regain or maintain body size in gradients of lakes with increasing fish species diversity. While allopatric in northern low-productive upland lakes, landlocked populations are commonly structured by cannibalism. In sympatry with other fish species, S. alpinus mostly serve as prey, with their decreasing growth and body size reflecting the successive diet shift from littoral macro-benthos to zooplankton and profundal microbenthos as interspecific competition for food and habitat intensifies. Interactions with natural and introduced superior zooplankton feeders and ultimate predators finally become detrimental. Consequently, the niche of S. alpinus is increasingly compressed in lakes along latitudinal and altitudinal gradients, although certain natural key conditions offer S. alpinus temporary asylum in the inescapable process towards local and regional extinction. The water temperature drop during winter allows S. alpinus to temporarily resume the richer littoral dietary and spatial niche use in low diversity lakes. In southern lowland and coastal lakes with more complex fish communities, access to key prey species such as profundal macro-crustaceans and smelt Osmerus spp. allow S. alpinus to regain its original niche space and characteristics as a large piscivore. In conclusion, S. alpinus along its

  20. Nature and Nurture in the Early-Life Origins of Metabolic Syndrome.

    PubMed

    Gonzalez-Bulnes, Antonio; Astiz, Susana; Ovilo, Cristina; Garcia-Contreras, Consolacion; Vazquez-Gomez, Marta

    2016-01-01

    The combination of genetic background together with food excess and lack of exercise has become the cornerstone of metabolic disorders associated to lifestyle. The scenario is furthermore reinforced by their interaction with other environmental factors (stress, sleeping patterns, education, culture, rural versus urban locations, and xenobiotics, among others) inducing epigenetic changes in the exposed individuals. The immediate consequence is the development of further alterations like obesity and metabolic syndrome, and other adverse health conditions (type-2 diabetes, cardiovascular diseases, cancer, reproductive, immune and neurological disorders). Thus, having in mind the impact of the metabolic syndrome on the worldwide public health, the present review affords the relative roles and the interrelationships of nature (genetic predisposition to metabolic syndrome) and nurture (lifestyle and environmental effects causing epigenetic changes), on the establishment of the metabolic disorders in women; disorders that may evolve to metabolic syndrome prior or during pregnancy and may be transmitted to their descendants. PMID:26927212

  1. Your Earliest Memory May Be Earlier than You Think: Prospective Studies of Children's Dating of Earliest Childhood Memories

    ERIC Educational Resources Information Center

    Wang, Qi; Peterson, Carole

    2014-01-01

    Theories of childhood amnesia and autobiographical memory development have been based on the assumption that the age estimates of earliest childhood memories are generally accurate, with an average age of 3.5 years among adults. It is also commonly believed that early memories will by default become inaccessible later on and this eventually…

  2. Effects of a natural toxin on life history and gene expression of Eisenia andrei.

    PubMed

    van Ommen Kloeke, A E Elaine; Gong, Ping; Ellers, Jacintha; Roelofs, Dick

    2014-02-01

    Earthworms perform key functions for a healthy soil ecosystem, such as bioturbation. The soil ecosystem can be challenged by natural toxins such as isothiocyanates (ITCs), produced by many commercial crops. Therefore, the effects of 2-phenylethyl ITC were investigated on the earthworm Eisenia andrei using an ecotoxicogenomics approach. Exposure to 2-phenylethyl ITC reduced both survival and reproduction of E. andrei in a dose-dependent manner (median effective concentration [EC50] = 556 nmol/g). Cross-species comparative genomic hybridization validated the applicability of an existing 4 × 44,000 Eisenia fetida microarray to E. andrei. Gene expression profiles revealed the importance of metallothionein (MT) as an early warning signal when E. andrei was exposed to low concentrations of 2-phenylethyl ITC. Alignment of these MT genes with the MT-2 gene of Lumbricus rubellus showed that at least 2 MT gene clusters are present in the Eisenia sp. genome. At high-exposure concentrations, gene expression was mainly affected by inhibiting chitinase activity, inducing an oxidative stress response, and stimulating energy metabolism. Furthermore, analysis by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway implied that the high concentration may have caused impaired light sensitivity, angiogenesis, olfactory perception, learning, and memory. Increased levels of ITCs may be found in the field in the near future. The results presented call for a careful investigation to quantify the risk of such compounds before allowing them to enter the soil on a large scale. PMID:24395740

  3. Beyond the Drake Equation: On the Probability of the Nature of Extraterrestrial Life Forms in Our Galaxy Today

    NASA Astrophysics Data System (ADS)

    Geller, Harold A.

    2014-01-01

    I will discuss my research into the issues associated with the nature of any extraterrestrials that may be encountered in the future in our galaxy. This research was sparked by statements made by Stephen Hawking in 2010 regarding his fear of emitting radiation from our Earth so that an extraterrestrial intelligent civilization may be alerted to our existence in the galaxy today. While addressing issues of extraterrestrial altruism, a probabilistic equation was developed which addresses the number of extraterrestrial intelligent life forms that may exist in our galaxy today, who could use our bodies for nourishment or reproductive purposes. The equation begins with the results from a Drake Equation calculation, and proceeds by addressing such biochemical parameters as the fraction of ETIs with: dextro sugar stereo-isomers; levo amino acid stereo-isomers; similar codon interpretation; chromosomal length and, similar cell membrane structure to allow egg penetration.

  4. Microbial biosynthesis of wax esters during desiccation: an adaptation for colonization of the earliest terrestrial environments?

    NASA Astrophysics Data System (ADS)

    Finkelstein, D. B.; Brassell, S. C.; Pratt, L. M.

    2008-12-01

    Biosynthesis of wax esters (WE) by prokaryotes in natural systems, notably bacteria from hot springs and marine phytoplankton, is poorly documented, primarily because saponification is a routine step in the analysis of microbial mat lipids. Use of this preparative procedure, critical for characterization of the diagnostic distributions of carboxylic acids in phospholipids, precludes recovery of intact WE. Examination of non-saponified lipids in emergent and desiccated mats with comparable microbial communities from the Warner Lake region, Oregon, reveals increases in the relative abundance (18.6 to 59.9μg/g Corg) and average chain length (C38 to C46) of WE in the latter, combined with assimilation of phytol and tocopherol moieties. Prokaryotes can accumulate WE as storage lipids in vitro, notably at elevated temperature or under nitrogen limiting conditions, but we propose that biosynthesis of long-chain WE that have a low solubility and are resistant to degradation/oxidation may represent an evolutionary strategy to survive desiccation in evaporative environments. Moreover, aeolian transport of desiccated mat-rip-ups between lake flats allows for migration of microbial communities within and between lake flats and basins during arid conditions. Subsequent rehydration within an alkaline environment would naturally saponify WE, and thereby regenerate alcohol and acid moieties that could serve as membrane lipids for the next viable microbial generation. The evolutionary cradle of WE was likely abiotic generation under hydrothermal conditions, which is consistent with the antiquity of the ester linkage necessitated by its integral role in the membranes of Eubacteria (though not Archaea) and in bacteriochlorophyll. The subsequent capability of microbes to biosynthesize WE may have facilitated their survival when nutrients were limiting, and production of long-chain WE (>C40) may represent a further critical evolutionary threshold that enabled their persistence through

  5. Thermodynamic metrics for aggregation of natural resources in life cycle analysis: insight via application to some transportation fuels.

    PubMed

    Baral, Anil; Bakshi, Bhavik R

    2010-01-15

    While methods for aggregating emissions are widely used and standardized in life cycle assessment (LCA), there is little agreement about methods for aggregating natural resources for obtaining interpretable metrics. Thermodynamic methods have been suggested including energy, exergy, and emergy analyses. This work provides insight into the nature of thermodynamic aggregation, including assumptions about substitutability between resources and loss of detailed information about the data being combined. Methods considered include calorific value or energy, industrial cumulative exergy consumption (ICEC) and its variations, and ecological cumulative exergy consumption (ECEC) or emergy. A hierarchy of metrics is proposed that spans the range from detailed data to aggregate metrics. At the fine scale, detailed data can help identify resources to whose depletion the selected product is most vulnerable. At the coarse scale, new insight is provided about thermodynamic aggregation methods. Among these, energy analysis is appropriate only for products that rely primarily on fossil fuels, and it cannot provide a useful indication of renewability. Exergy-based methods can provide results similar to energy analysis by including only nonrenewable fuels but can also account for materials use and provide a renewability index. However, ICEC and its variations do not address substitutability between resources, causing its results to be dominated by dilute and low-quality resources such as sunlight. The use of monetary values to account for substitutability does not consider many ecological resources and may not be appropriate for the analysis of emerging products. ECEC or emergy explicitly considers substitutability and resource quality and provides more intuitive results but is plagued by data gaps and uncertainties. This insight is illustrated via application to the life cycles of gasoline, diesel, corn ethanol, and soybean biodiesel. Here, aggregate metrics reveal the dilemma

  6. Elevated Appraisals of the Negative Impact of Naturally Occurring Life Events: A Risk Factor for Depressive and Anxiety Disorders

    PubMed Central

    Espejo, Emmanuel P.; Hammen, Constance; Brennan, Patricia A.

    2012-01-01

    The tendency to appraise naturally occurring life events (LEs) as having high negative impact may be a predisposing factor for the development of depression and anxiety disorders. In the current study, appraisals of the negative impact of recent LEs were examined in relationship to depressive and anxiety disorders in a sample of 653 adolescents who were administered diagnostic and life stress interviews at ages 15 and 20. Participants’ appraisals of the negative impact of LEs reported at age 15 were statistically adjusted using investigator-based ratings to control for objective differences across LEs. Higher appraisals of the negative impact of LEs were associated with both past and current depressive and anxiety disorders at age 15 and predicted subsequent first onsets of depressive and anxiety disorders occurring between ages 15 and 20. In addition, appraisals of the negative impact of LEs were particularly elevated among those experiencing both a depressive and anxiety disorder over the course of the study. The findings suggest that systematically elevated appraisals of the negative impact of LEs is a predisposing factor for depression and anxiety disorders and may represent a specific risk factor for co-morbid depression and anxiety in mid-adolescence and early adulthood. Keywords: depression; anxiety; stress appraisals; prospective study; PMID:21845380

  7. Astronomy in Ireland from earliest times to the eighteenth century

    NASA Astrophysics Data System (ADS)

    McKenna-Lawlor, Susan M. P.

    Evidence that the builders of Irish passage graves and stone circles may have possessed some knowledge of basic celestial cycles is discussed. The introduction of Celtic culture to Ireland circa 600 B.C. is next described and an account of the astronomical learning of the Celts provided based on classical documentation and Irish vernacular sources. Following on the coming of Christianity to Ireland in the fifth century, the necessity to construct Easter tables led Irish monks to such related activities as establishing collections of computi, compiling Annals and undertaking studies of available astronomical material. In particular, through exposure to Helenistic writings, they understood celestial motions in terms of the Ptolemaic model and were recognised authorities in Europe in the eighth and ninth centuries on astronomical matters. The influence of the Viking and Norman invasions in disrupting the intellectual life of the country is then outlined and the circumstances relating to the creation of conditions leading to the brilliant flowering of Irish astronomy in the eighteenth century are elucidated.

  8. The Origin and Earliest History of the Earth

    NASA Astrophysics Data System (ADS)

    Halliday, A. N.

    The past 10 years have seen major advances in our understanding of how Earth first developed. With better measurements of circumstellar disk life times and new theories for the Moon-forming giant impact, driven by improvements in theory and modeling that are tensioned against new kinds of isotopic and other geochemical constraints, the origins of Earth-like planets have never been clearer. This is particularly interesting and relevant to the current search for exosolar habitable environments. Isotope geochemistry provides powerful evidence that Earth formed over a protracted period of more than 30 Ma, culminating in the giant impact. Oxygen and titanium isotopes provide evidence that most of the atoms in the Moon were derived from Earth requiring revisions to giant impact simulations. The core started forming early and we now have clear isotopic evidence that silicon is one of the light constituents. The origins of Earth's volatiles are still debated, but there is increasing evidence for the importance of chondrites and comets as opposed to solar volatiles. The timing and importance of any late veneer are still debated, while new isotopic data provide unequivocal evidence of early mantle heterogeneity, much of which has been eliminated with billions of years of mantle convective mixing.

  9. Hubble's deepest view ever of the Universe unveils earliest galaxies

    NASA Astrophysics Data System (ADS)

    2004-03-01

    Hubble sees galaxies galore hi-res Size hi-res: 446 kb Credits: NASA, ESA, and S. Beckwith (STScI) and the HUDF Team Hubble sees galaxies galore Galaxies, galaxies everywhere - as far as the NASA/ESA Hubble Space Telescope can see. This view of nearly 10,000 galaxies is the deepest visible-light image of the cosmos. Called the Hubble Ultra Deep Field, this galaxy-studded view represents a ‘deep’ core sample of the universe, cutting across billions of light-years. Hubble reveals galactic drama hi-res Size hi-res: 879 kb Credits: NASA, ESA, and S. Beckwith (STScI) and the HUDF Team Hubble reveals galactic drama A galactic brawl. A close encounter with a spiral galaxy. Blue wisps of galaxies. These close-up snapshots of galaxies in the Hubble Ultra Deep Field reveal the drama of galactic life. Here three galaxies just below centre are enmeshed in battle, their shapes distorted by the brutal encounter. Hubble reveals galactic drama hi-res Size hi-res: 886 kb Credits: NASA, ESA, and S. Beckwith (STScI) and the HUDF Team Hubble reveals galactic drama A galactic brawl. A close encounter with a spiral galaxy. Blue wisps of galaxies. These close-up snapshots of galaxies in the Hubble Ultra Deep Field reveal the drama of galactic life. Here three galaxies just below centre are enmeshed in battle, their shapes distorted by the brutal encounter. Hubble reveals galactic drama hi-res Size hi-res: 892 kb Credits: NASA, ESA, and S. Beckwith (STScI) and the HUDF Team Hubble reveals galactic drama A galactic brawl. A close encounter with a spiral galaxy. Blue wisps of galaxies. These close-up snapshots of galaxies in the Hubble Ultra Deep Field reveal the drama of galactic life. The galaxies in this panel were plucked from a harvest of nearly 10,000 galaxies in the Ultra Deep Field, the deepest visible-light image of the cosmos. This historic new view is actually made up by two separate images taken by Hubble's Advanced Camera for Surveys (ACS) and the Near Infrared Camera and

  10. Life cycle greenhouse gas emissions from U.S. liquefied natural gas exports: implications for end uses.

    PubMed

    Abrahams, Leslie S; Samaras, Constantine; Griffin, W Michael; Matthews, H Scott

    2015-03-01

    This study analyzes how incremental U.S. liquefied natural gas (LNG) exports affect global greenhouse gas (GHG) emissions. We find that exported U.S. LNG has mean precombustion emissions of 37 g CO2-equiv/MJ when regasified in Europe and Asia. Shipping emissions of LNG exported from U.S. ports to Asian and European markets account for only 3.5-5.5% of precombustion life cycle emissions, hence shipping distance is not a major driver of GHGs. A scenario-based analysis addressing how potential end uses (electricity and industrial heating) and displacement of existing fuels (coal and Russian natural gas) affect GHG emissions shows the mean emissions for electricity generation using U.S. exported LNG were 655 g CO2-equiv/kWh (with a 90% confidence interval of 562-770), an 11% increase over U.S. natural gas electricity generation. Mean emissions from industrial heating were 104 g CO2-equiv/MJ (90% CI: 87-123). By displacing coal, LNG saves 550 g CO2-equiv per kWh of electricity and 20 g per MJ of heat. LNG saves GHGs under upstream fugitive emissions rates up to 9% and 5% for electricity and heating, respectively. GHG reductions were found if Russian pipeline natural gas was displaced for electricity and heating use regardless of GWP, as long as U.S. fugitive emission rates remain below the estimated 5-7% rate of Russian gas. However, from a country specific carbon accounting perspective, there is an imbalance in accrued social costs and benefits. Assuming a mean social cost of carbon of $49/metric ton, mean global savings from U.S. LNG displacement of coal for electricity generation are $1.50 per thousand cubic feet (Mcf) of gaseous natural gas exported as LNG ($.028/kWh). Conversely, the U.S. carbon cost of exporting the LNG is $1.80/Mcf ($.013/kWh), or $0.50-$5.50/Mcf across the range of potential discount rates. This spatial shift in embodied carbon emissions is important to consider in national interest estimates for LNG exports. PMID:25650513

  11. Age estimates of the seaward-dipping volcanic wedge, earliest oceanic crust, and earliest drift-stage sediments along the North American Atlantic continental margin

    NASA Astrophysics Data System (ADS)

    Benson, Richard N.

    Owing to their depths of burial along and adjacent to the North American continental margin, there is no direct evidence obtained from boreholes for the ages of the seaward-dipping volcanic wedge, earliest drift-stage sediments overlying the wedge, and the earliest Atlantic oceanic crust between the East Coast (ECMA) and Blake Spur (BSMA) magnetic anomalies. Maximum ages of late Sinemurian for drift-stage sediments have been determined from exploration wells in the Scotian Basin. A similar age is postulated for those sediments in the Georges Bank Basin, but palynomorphs from exploration wells may indicate that earliest drift-stage sediments, in places associated with volcanic rocks, are of Bajocian age and occur higher in the section above the postrift unconformity as recognized on seismic lines. In the Southeast Georgia Embayment of the Blake Plateau Basin, the oldest drift-stage sediments overlying the postrift unconformity that were drilled are of Kimmeridgian-Tithonian age. In the Baltimore Canyon Trough, the volcanic wedge overlies the postrift unconformity which truncates buried synrift rocks that may be as young as Sinemurian. In the Carolina Trough and Blake Plateau Basin, a possible offshore flood basalt marking the postrift unconformity and traced as a reflector to the volcanic wedge may correspond to a subsurface flood basalt onshore that may be part of CAMP (Hettangian). Alternatively, its magmatic source may have been that of the possibly younger volcanic wedge. Sea-floor-spreading-rate lines based on the latest Jurassic time scales and extended to the BSMA and ECMA indicate ages of 166 and 171 Ma for the BSMA and 172 and 179 Ma for the ECMA. An alternative model suggests a middle Pliensbachian/early Toarcian age (188-190 Ma) for the igneous activity that produced the volcanic wedge and earliest oceanic crust.

  12. Earliest Phanerozoic or latest Proterozoic fossils from the Arabian Shield

    USGS Publications Warehouse

    Cloud, P.; Awramik, S.M.; Morrison, K.; Hadley, D.G.

    1979-01-01

    We report here the first biologically definable fossils from pre-Saq (pre-Middle Cambrian) rocks of the Arabian Shield. They include the distinctive helically coiled tubular filaments of the oscillatorialean blue-green alga Obruchevella parva as well as two size classes of spheroidal unicells of uncertain affinity. Also present is the conical stromatolite Conophyton and unidentified stromatolites. All occur in cherty limestones of the Jubaylah Group, northern Saudi Arabia, a nonmarine to locally marine taphrogeosynclinal sequence that fills depressions along the northwest-trending Najd faults. Conophyton has heretofore been found only in strata older than about 680 Ma (except for puzzling records in modern hot springs) while Obruchevella is so far known only from rocks between about 680 and 470 Ma old. Thus it appears that the Jubaylah Group is close to the Proterozoic-Phanerozoic transition. The simple spheroidal nanno-fossils are not diagnostic as to age. Their relationships within what appears to be early diagenetic chert suggest a classical algal-mat association. The brecciated and microchanneled appearance of much of the fossiliferous rock, its locally dolomitic nature, and the prevalence of cryptalgalaminate favors a very shallow, locally turbulent, and perhaps episodically exposed marine or marginal marine setting. The Jubaylah Group lies unconformably beneath the Siq Sandstone (basal member of the Saq Sandstone) of medial Cambrian age, rests nonconformably on crystalline basement, and has yielded a K-Ar whole-rock age (on andesitic basalt) of ???540 Ma. To judge from the fossils, however, that age may be as much as 100 Ma or more too young. ?? 1979.

  13. Earliest abort once around time for the first orbital flight test mission

    NASA Technical Reports Server (NTRS)

    Kuhn, A. E.

    1975-01-01

    The earliest abort once around (AOA) time for the first orbital flight test (OFT-1) mission is determined. The latest estimates of vehicle weights and propulsion for OFT-1 are used. Trade analyses to indicate variations in AOA time for shuttle subsystem changes (such as orbital maneuvering system (OMS) or reaction control system (RCS) propellant loadings) are included. In addition, the effects of first stage attitude steering as a function of relative velocity for a nominal profile are presented. Data are presented to indicate the effect of designing first stage steering for earliest AOA time and then having engine out at times after the design point.

  14. The potential effects of sodium bicarbonate, a major constituent from coalbed natural gas production, on aquatic life

    USGS Publications Warehouse

    Farag, Aida M.; Harper, David D.

    2012-01-01

    The production water from coalbed natural gas (CBNG) extraction contains many constituents. The U.S. Environmental Protection Agency has established aquatic life criteria for some of these constituents, and it is therefore possible to evaluate their risk to aquatic life. However, of the major ions associated with produced waters, chloride is the only one with an established aquatic life criterion (U.S. Environmental Protection Agency, 1988). The focus of this research was NaHCO3, a compound that is a major constituent of coalbed natural gas produced waters in the Tongue and Powder River Basins. This project included laboratory experiments, field in situ experiments, a field mixing zone study, and a fishery presence/absence assessment. Though this investigation focuses on the Tongue and Powder River Basins, the information is applicable to other watersheds where sodium bicarbonate is a principle component of product water either from CBNG or from traditional or unconventional oil and gas development. These data can also be used to separate effects of saline discharges from those potentially posed by other constituents. Finally, this research effort and the additional collaboration with USGS Water Resources and Mapping, Bureau of Land Management, US Environmental Protection Agency, State of Montana, State of Wyoming, Montana State University, University of Wyoming, and others as part of a Powder River Aquatic Task Group, can be used as a model for successful approaches to studying landscapes with energy development. The laboratory acute toxicity experiments were completed with a suite of organisms, including 7 species of fish, 5 species of invertebrates, and 1 amphibian species. Experiments performed on these multiple species resulted in LC50s that ranged from 1,120 to greater than (>) 8,000 milligrams sodium bicarbonate per liter (mg NaHCO3/L) (also defined as 769 to >8,000 milligrams bicarbonate per liter (mg HCO3-/L) or total alkalinity expressed as 608 to >4

  15. Glycine Identification in Natural Jarosites Using Laser Desorption Fourier Transform Mass Spectrometry: Implications for the Search for Life on Mars

    NASA Astrophysics Data System (ADS)

    Kotler, J. Michelle; Hinman, Nancy W.; Yan, Beizhan; Stoner, Daphne L.; Scott, Jill R.

    2008-04-01

    The jarosite group minerals have received increasing attention since the discovery of jarosite on the martian surface by the Mars Exploration Rover Opportunity. Given that jarosite can incorporate foreign ions within its structure, we have investigated the use of jarosite as an indicator of aqueous and biological processes on Earth and Mars. The use of laser desorption Fourier transform mass spectrometry has revealed the presence of organic matter in several jarosite samples from various locations worldwide. One of the ions from the natural jarosites has been attributed to glycine because it was systematically observed in combinations of glycine with synthetic ammonium and potassium jarosites, Na2SO4 and K2SO4. The ability to observe these organic signatures in jarosite samples with an in situ instrumental technique, such as the one employed in this study, furthers the goals of planetary geologists to determine whether signs of life (e.g., the presence of biomolecules or biomolecule precursors) can be detected in the rock record of terrestrial and extraterrestrial samples.

  16. Nature of bacterial colonization influences transcription of mucin genes in mice during the first week of life

    PubMed Central

    2012-01-01

    Background Postnatal regulation of the small intestinal mucus layer is potentially important in the development of adult gut functionality. We hypothesized that the nature of bacterial colonization affects mucus gene regulation in early life. We thus analyzed the influence of the presence of a conventional microbiota as well as two selected monocolonizing bacterial strains on the transcription of murine genes involved in mucus layer development during the first week of life. Mouse pups (N = 8/group) from differently colonized dams: Germ-free (GF), conventional specific pathogen free (SPF), monocolonized with either Lactobacillus acidophilus NCFM (Lb) or Escherichia coli Nissle (Ec) were analyzed by qPCR on isolated ileal tissue sections from postnatal days 1 and 6 (PND1, PND6) after birth with respect to: (i) transcription of specific genes involved in mucus production (Muc1-4, Tff3) and (ii) amounts of 16S rRNA of Lactobacillus and E. coli. Quantification of 16S rRNA genes was performed to obtain a measure for amounts of colonized bacteria. Results We found a microbiota-independent transcriptional increase of all five mucus genes from PND1 to PND6. Furthermore, the relative level of transcription of certain mucus genes on PND1 was increased by the presence of bacteria. This was observed for Tff3 in the SPF, Ec, and Lb groups; for Muc2 in SPF; and for Muc3 and Muc4 in Ec and Lb, respectively. Detection of bacterial 16S rRNA genes levels above the qPCR detection level occurred only on PND6 and only for some of the colonized animals. On PND6, we found significantly lower levels of Muc1, Muc2 and Muc4 gene transcription for Lb animals with detectable Lactobacillus levels as compared to animals with Lactobacillus levels below the detection limit. Conclusions In summary, our data show that development of the expression of genes encoding secreted (Muc2/Tff3) and membrane-bound (Muc1/Muc3/Muc4) mucus regulatory proteins, respectively, is distinct and that the onset of

  17. Life in Extreme Environments

    NASA Technical Reports Server (NTRS)

    McKay, Christopher P.; Young, Richard E. (Technical Monitor)

    1997-01-01

    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.

  18. The power of visual memory: the earliest remembered drawing of Alberto Giacometti, Snow White in Her Coffin.

    PubMed

    Wilson, Laurie

    2008-04-01

    Since the time of Freud, many psychoanalysts have seen screen memories and earliest memories as reflecting underlying dynamics. I propose that an earliest remembered artwork is a highly condensed construction similar to a screen memory. Alberto Giacometti's earliest remembered drawing, of Snow White in Her Coffin, contains clues to the artist's personality and references to childhood experience. Giacometti's memory of the drawing done in childhood is a striking condensation of significant biographical events and psychodynamic conflicts, as well as a marker of important unconscious fantasies. The artist's postwar sculptural style, utilizing gaunt figures, epitomizes the final transformation of the psychological meaning of his earliest remembered drawing. PMID:18512362

  19. Earliest Memories and Recent Memories of Highly Salient Events--Are They Similar?

    ERIC Educational Resources Information Center

    Peterson, Carole; Fowler, Tania; Brandeau, Katherine M.

    2015-01-01

    Four- to 11-year-old children were interviewed about 2 different sorts of memories in the same home visit: recent memories of highly salient and stressful events--namely, injuries serious enough to require hospital emergency room treatment--and their earliest memories. Injury memories were scored for amount of unique information, completeness…

  20. Gathering Together: A View of the Earliest Student Affairs Professional Organizations

    ERIC Educational Resources Information Center

    Gerda, Janice J.

    2006-01-01

    In November 1903, 18 women gathered together for the Conference of Deans of Women of the Middle West. Variations of this conference were held over the following 20 years, constituting the earliest period of professional association in what was to become known as student affairs. When creating their associations, the early deans needed to consider…

  1. Infantile Amnesia across the Years: A 2-Year Follow-Up of Children's Earliest Memories

    ERIC Educational Resources Information Center

    Peterson, Carole; Warren, Kelly L.; Short, Megan M.

    2011-01-01

    Although infantile amnesia has been investigated for many years in adults, only recently has it been investigated in children. This study was a 2-year follow-up and extension of an earlier study. Children (4-13 years old) were asked initially and 2 years later for their earliest 3 memories. At follow-up, their age at the time of these memories…

  2. Maternal Reminiscing Style during Early Childhood Predicts the Age of Adolescents' Earliest Memories

    ERIC Educational Resources Information Center

    Jack, Fiona; MacDonald, Shelley; Reese, Elaine; Hayne, Harlene

    2009-01-01

    Individual differences in parental reminiscing style are hypothesized to have long-lasting effects on children's autobiographical memory development, including the age of their earliest memories. This study represents the first prospective test of this hypothesis. Conversations about past events between 17 mother-child dyads were recorded on…

  3. Natural history of Ctenus medius Keyserling, 1891 (Araneae, Ctenidae). II: Life cycle and aspects of reproductive behavior under laboratory conditions.

    PubMed

    Folly-Ramos, E; Almeida, C E; Carmo-Silva, M; Costa, J

    2002-11-01

    Ctenus medius Keyserling, 1891 is a wandering spider common in the Brazilian Atlantic Forest. It has been the subject of few studies. Thus, this work aims to elucidate aspects of its natural history, such as the life cycle and reproductive behavior of this species, through laboratory and field observations. Two females with egg sacs were observed in the laboratory and one was observed in field (Barra Mansa, 22 degrees 32'S and 44 degrees 10'W) until the emergence of the spiderlings. For observation of the immature stage development, a portion of the spiderlings from the same hatch were taken to the laboratory and watched until sexual maturity. In the field, the period between the oviposition and the emergence of spiderlings was of 36 days. The female selects a site for egg sac deposition and stays there until the spiderlings emerge. Seven days after the emergence, the female abandoned the site where the egg sac was made, concomitant to the spiderlings dispersion from observation's place and until the moment that the spiderlings started to eat. For the spiderlings kept under laboratory conditions, cannibalism was not observed in the first instars (1-4th) when sufficient food was offered. Sexual maturity happened in the 14th or 15th instars, with an average of 309.2 to 344.5 days until the last/sexual molt, respectively. Until the date of sexual maturity, there was a mortality rate of 85%. This species is very fragile in captivity. This hampered deductions concerning longevity. Both females and males collected in the field were induced to mate in the laboratory. Courtship movements of males were registered, but the females did not permit the mating. These data may assist in initial biological studies of Ctenus genus and offer comparative parameters for studies of other related species. PMID:12659029

  4. Heritability of life-history tactics and genetic correlation with body size in a natural population of brook charr (Salvelinus fontinalis).

    PubMed

    Thériault, V; Garant, D; Bernatchez, L; Dodson, J J

    2007-11-01

    A common dimorphism in life-history tactic in salmonids is the presence of an anadromous pathway involving a migration to sea followed by a freshwater reproduction, along with an entirely freshwater resident tactic. Although common, the genetic and environmental influence on the adoption of a particular life-history tactic has rarely been studied under natural conditions. Here, we used sibship-reconstruction based on microsatellite data and an 'animal model' approach to estimate the additive genetic basis of the life-history tactic adopted (anadromy vs. residency) in a natural population of brook charr, Salvelinus fontinalis. We also assess its genetic correlation with phenotypic correlated traits, body size and body shape. Significant heritability was observed for life-history tactic (varying from 0.52 to 0.56 depending on the pedigree scenario adopted) as well as for body size (from 0.44 to 0.50). There was also a significant genetic correlation between these two traits, whereby anadromous fish were genetically associated with bigger size at age 1 (r(G) = -0.52 and -0.61). Our findings thus indicate that life-history tactics in this population have the potential to evolve in response to selection acting on the tactic itself or indirectly via selection on body size. This study is one of the very few to have successfully used sibship-reconstruction to estimate quantitative genetic parameters under wild conditions. PMID:17956389

  5. Life cycle air emissions impacts and ownership costs of light-duty vehicles using natural gas as a primary energy source.

    PubMed

    Luk, Jason M; Saville, Bradley A; MacLean, Heather L

    2015-04-21

    This paper aims to comprehensively distinguish among the merits of different vehicles using a common primary energy source. In this study, we consider compressed natural gas (CNG) use directly in conventional vehicles (CV) and hybrid electric vehicles (HEV), and natural gas-derived electricity (NG-e) use in plug-in battery electric vehicles (BEV). This study evaluates the incremental life cycle air emissions (climate change and human health) impacts and life cycle ownership costs of non-plug-in (CV and HEV) and plug-in light-duty vehicles. Replacing a gasoline CV with a CNG CV, or a CNG CV with a CNG HEV, can provide life cycle air emissions impact benefits without increasing ownership costs; however, the NG-e BEV will likely increase costs (90% confidence interval: $1000 to $31 000 incremental cost per vehicle lifetime). Furthermore, eliminating HEV tailpipe emissions via plug-in vehicles has an insignificant incremental benefit, due to high uncertainties, with emissions cost benefits between -$1000 and $2000. Vehicle criteria air contaminants are a relatively minor contributor to life cycle air emissions impacts because of strict vehicle emissions standards. Therefore, policies should focus on adoption of plug-in vehicles in nonattainment regions, because CNG vehicles are likely more cost-effective at providing overall life cycle air emissions impact benefits. PMID:25825338

  6. Comparing the composition of the earliest basalts erupted by the Iceland and Afar mantle plumes.

    NASA Astrophysics Data System (ADS)

    Stuart, Finlay M.

    2013-04-01

    The first basalts erupted by mantle plumes are typically generated by mantle melting at temperatures 200-300°C higher than average ambient mantle. This is consistent with the derivation of from a thermal boundary layer at the core-mantle boundary. Mantle plume temperatures decrease with time, likely as large plume heads give way to thin plume conduits. Consequently the early, hot plume basalts are a window into the deep mantle. At it's simplest they provide a test of whether the discrete plume source regions are primordial mantle that have been isolated since soon after Earth accretion, or have substantial contributions from subducted slabs. Here I present new isotopic and trace element determinations of the earliest picritic basalts from the ~30 Ma Afar plume in Ethiopia. They will be compared with similar material from the ~60 Ma proto-Iceland plume (PIP) in an effort to test prevailing models regarding the source of mantle plumes. The extremely primordial nature of the helium in the PIP picrites (3He/4He ~ 50 Ra) contrasts with much lower values of the Ethiopian flood basalt province (~21 Ra). The Iceland plume 3He/4He has decreased (linearly) with time, mirroring the secular cooling of the Iceland mantle plume identified by decreasing MgO and FeO in primary melts. In 60 million years the Iceland plume 3He/4He is still higher than the maximum Afar plume value. The Sr-Nd-Pb isotopic composition of the high 3He/4He Ethiopian flood basalt province picrites are remarkably homogenous (e.g. 87Sr/86Sr = 0.70396-0.70412; 206Pb/204Pb = 18.82-19.01). In comparison the PIP picrites have ranges that span nearly the global range of E-MORB and N-MORB. The Afar and proto-Iceland mantle plumes are clearly not initiated in a single deep mantle domain with the same depletion/enrichment and degassing histories, and the same scale of heterogeneity. This implies that there is more than one plume source region/mechanism that is capable of generating comparable volumes of basalt melt

  7. Signatures of natural selection in the mitochondrial genomes of Tachycineta swallows and their implications for latitudinal patterns of the 'pace of life'.

    PubMed

    Stager, Maria; Cerasale, David J; Dor, Roi; Winkler, David W; Cheviron, Zachary A

    2014-08-01

    Latitudinal variation in avian life histories can be summarized as a slow-fast continuum, termed the 'pace of life', that encompasses patterns in life span, reproduction, and rates of development among tropical and temperate species. Much of the variation in avian pace of life is tied to differences in rates of long-term metabolic energy expenditure. Given the vital role of the mitochondrion in metabolic processes, studies of variation in the mitochondrial genome may offer opportunities to establish mechanistic links between genetic variation and latitudinal 'pace of life' patterns. Using comparative genomic analyses, we examined complete mitochondrial genome sequences obtained from nine, broadly distributed Tachycineta swallow species to test for signatures of natural selection across the mitogenome within a phylogenetic framework. Our results show that although purifying selection is the dominant selective force acting on the mitochondrial genome in Tachycineta, three mitochondrial genes (ND2, ND5, and CYTB) contain regions that exhibit signatures of diversifying selection. Two of these genes (ND2 and ND5) encode interacting subunits of NADH dehydrogenase, and amino residues that were inferred to be targets of positive selection were disproportionately concentrated in these genes. Moreover, the positively selected sites exhibited a phylogenetic pattern that could be indicative of adaptive divergence between "fast" and "slow" lineages. These results suggest that functional variation in cytochrome b and NADH dehydrogenase could mechanistically contribute to latitudinal 'pace of life' patterns in Tachycineta. PMID:24814189

  8. An experimental 'Life' for an experimental life: Richard Waller's biography of Robert Hooke (1705).

    PubMed

    Moxham, Noah

    2016-03-01

    Richard Waller's 'Life of Dr Robert Hooke', prefixed to his edition of Hooke's Posthumous Works (1705), is an important source for the life of one of the most eminent members of the early Royal Society. It also has the distinction of being one of the earliest biographies of a man of science to be published in English. I argue that it is in fact the first biography to embrace the subject's natural-philosophical work as the centre of his life, and I investigate Waller's reasons for adopting this strategy and his struggle with the problem of how to represent an early experimental philosopher in print. I suggest that Waller eschews the 'Christian philosopher' tradition of contemporary biography - partly because of the unusually diverse and fragmentary nature of Hooke's intellectual output - and draws instead upon the structure of the Royal Society's archive as a means of organizing and understanding Hooke's life. The most quoted phrase from Waller's biography is that Hooke became 'to a crime close and reserved' in later life; this essay argues that Waller's biographical sketch was fashioned in order to undo the effects of that reserve. In modelling his approach very closely on the structure of the society's records he was principally concerned with making Hooke's work and biography accessible, intelligible and useful to the fellowship in a context familiar to them, a context which had provided the institutional framework for most of Hooke's adult life. I argue that Waller's 'Life' was also intended to make the largest claims for Hooke's intellectual standing that the author dared in the context of the enmity between Hooke and Isaac Newton once the latter became president of the Royal Society. However, I also adduce fresh manuscript evidence that Waller actually compiled, but did not publish, a defence of Hooke's claim to have discovered the inverse square law of gravity, allowing us to glimpse a much more assertive biography of Hooke than the published version. PMID

  9. The Laws of Nature and the Origin of Life in Pupils' Consciousness: A Study of Contradictory Modes of Thought.

    ERIC Educational Resources Information Center

    Engestrom, Yrjo

    1981-01-01

    Data identified two essential contradictions within the development of Finnish primary and secondary pupils' natural-scientific consciousness: one between the dominant biological-biologistic conception and the emerging physical-chemical or universal conception of the laws of nature; the other between religious and natural-scientific conceptions of…

  10. Conceptual design study on very small long-life gas cooled fast reactor using metallic natural Uranium-Zr as fuel cycle input

    NASA Astrophysics Data System (ADS)

    Monado, Fiber; Ariani, Menik; Su'ud, Zaki; Waris, Abdul; Basar, Khairul; Aziz, Ferhat; Permana, Sidik; Sekimoto, Hiroshi

    2014-02-01

    A conceptual design study of very small 350 MWth Gas-cooled Fast Reactors with Helium coolant has been performed. In this study Modified CANDLE burn-up scheme was implemented to create small and long life fast reactors with natural Uranium as fuel cycle input. Such system can utilize natural Uranium resources efficiently without the necessity of enrichment plant or reprocessing plant. The core with metallic fuel based was subdivided into 10 regions with the same volume. The fresh Natural Uranium is initially put in region-1, after one cycle of 10 years of burn-up it is shifted to region-2 and the each region-1 is filled by fresh Natural Uranium fuel. This concept is basically applied to all axial regions. The reactor discharge burn-up is 31.8% HM. From the neutronic point of view, this design is in compliance with good performance.

  11. Conceptual design study on very small long-life gas cooled fast reactor using metallic natural Uranium-Zr as fuel cycle input

    SciTech Connect

    Monado, Fiber; Ariani, Menik; Su'ud, Zaki; Waris, Abdul; Basar, Khairul; Permana, Sidik; Aziz, Ferhat; Sekimoto, Hiroshi

    2014-02-12

    A conceptual design study of very small 350 MWth Gas-cooled Fast Reactors with Helium coolant has been performed. In this study Modified CANDLE burn-up scheme was implemented to create small and long life fast reactors with natural Uranium as fuel cycle input. Such system can utilize natural Uranium resources efficiently without the necessity of enrichment plant or reprocessing plant. The core with metallic fuel based was subdivided into 10 regions with the same volume. The fresh Natural Uranium is initially put in region-1, after one cycle of 10 years of burn-up it is shifted to region-2 and the each region-1 is filled by fresh Natural Uranium fuel. This concept is basically applied to all axial regions. The reactor discharge burn-up is 31.8% HM. From the neutronic point of view, this design is in compliance with good performance.

  12. Attention modulates earliest responses in the primary auditory and visual cortices.

    PubMed

    Poghosyan, Vahe; Ioannides, Andreas A

    2008-06-12

    A fundamental question about the neural correlates of attention concerns the earliest sensory processing stage that it can affect. We addressed this issue by recording magnetoencephalography (MEG) signals while subjects performed detection tasks, which required employment of spatial or nonspatial attention, in auditory or visual modality. Using distributed source analysis of MEG signals, we found that, contrary to previous studies that used equivalent current dipole (ECD) analysis, spatial attention enhanced the initial feedforward response in the primary visual cortex (V1) at 55-90 ms. We also found attentional modulation of the putative primary auditory cortex (A1) activity at 30-50 ms. Furthermore, we reproduced our findings using ECD modeling guided by the results of distributed source analysis and suggest a reason why earlier studies using ECD analysis failed to identify the modulation of earliest V1 activity. PMID:18549790

  13. The Fate of Childhood Memories: Children Postdated Their Earliest Memories as They Grew Older

    PubMed Central

    Wang, Qi; Peterson, Carole

    2016-01-01

    Childhood amnesia has been attributed to the inaccessibility of early memories as children grow older. We propose that systematic biases in the age estimates of memories may play a role. A group of 4- to 9-year-olds children were followed for 8 years, recalling and dating their earliest childhood memories at three time points. Although children retained many of the memories over time, their age estimates of these memories shifted forward in time, to later ages. The magnitude of postdating was especially sizable for earlier memories and younger children such that some memories were dated more than a year later than originally. As a result, the boundary of childhood amnesia increased with age. These findings shed light on childhood amnesia and the fate of early memories. They further suggest that generally accepted estimates for people’s age of earliest memory may be wrong, which has far-reaching implications. PMID:26793149

  14. Natural pH Gradients in Hydrothermal Alkali Vents Were Unlikely to Have Played a Role in the Origin of Life.

    PubMed

    Jackson, J Baz

    2016-08-01

    The hypothesis that a natural pH gradient across inorganic membranes lying between the ocean and fluid issuing from hydrothermal alkali vents provided energy to drive chemical reactions during the origin of life has an attractive parallel with chemiosmotic ATP synthesis in present-day organisms. However, arguments raised in this review suggest that such natural pH gradients are unlikely to have played a part in life's origin. There is as yet no evidence for thin inorganic membranes holding sharp pH gradients in modern hydrothermal alkali vents at Lost City near the Mid-Atlantic Ridge. Proposed models of non-protein forms of the H(+)-pyrophosphate synthase that could have functioned as a molecular machine utilizing the energy of a natural pH gradient are unsatisfactory. Some hypothetical designs of non-protein motors utilizing a natural pH gradient to drive redox reactions are plausible but complex, and such motors are deemed unlikely to have assembled by chance in prebiotic times. Small molecular motors comprising a few hundred atoms would have been unable to function in the relatively thick (>1 μm) inorganic membranes that have hitherto been used as descriptive models for the natural pH gradient hypothesis. Alternative hypotheses for the evolution of chemiosmotic systems following the emergence of error-prone gene replication and translation are more likely to be correct. PMID:27534947

  15. 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.

  16. The characteristics and chronology of the earliest Acheulean at Konso, Ethiopia.

    PubMed

    Beyene, Yonas; Katoh, Shigehiro; Woldegabriel, Giday; Hart, William K; Uto, Kozo; Sudo, Masafumi; Kondo, Megumi; Hyodo, Masayuki; Renne, Paul R; Suwa, Gen; Asfaw, Berhane

    2013-01-29

    The Acheulean technological tradition, characterized by a large (>10 cm) flake-based component, represents a significant technological advance over the Oldowan. Although stone tool assemblages attributed to the Acheulean have been reported from as early as circa 1.6-1.75 Ma, the characteristics of these earliest occurrences and comparisons with later assemblages have not been reported in detail. Here, we provide a newly established chronometric calibration for the Acheulean assemblages of the Konso Formation, southern Ethiopia, which span the time period ∼1.75 to <1.0 Ma. The earliest Konso Acheulean is chronologically indistinguishable from the assemblage recently published as the world's earliest with an age of ∼1.75 Ma at Kokiselei, west of Lake Turkana, Kenya. This Konso assemblage is characterized by a combination of large picks and crude bifaces/unifaces made predominantly on large flake blanks. An increase in the number of flake scars was observed within the Konso Formation handaxe assemblages through time, but this was less so with picks. The Konso evidence suggests that both picks and handaxes were essential components of the Acheulean from its initial stages and that the two probably differed in function. The temporal refinement seen, especially in the handaxe forms at Konso, implies enhanced function through time, perhaps in processing carcasses with long and stable cutting edges. The documentation of the earliest Acheulean at ∼1.75 Ma in both northern Kenya and southern Ethiopia suggests that behavioral novelties were being established in a regional scale at that time, paralleling the emergence of Homo erectus-like hominid morphology. PMID:23359714

  17. The characteristics and chronology of the earliest Acheulean at Konso, Ethiopia

    PubMed Central

    Beyene, Yonas; Katoh, Shigehiro; WoldeGabriel, Giday; Hart, William K.; Uto, Kozo; Sudo, Masafumi; Kondo, Megumi; Hyodo, Masayuki; Renne, Paul R.; Suwa, Gen; Asfaw, Berhane

    2013-01-01

    The Acheulean technological tradition, characterized by a large (>10 cm) flake-based component, represents a significant technological advance over the Oldowan. Although stone tool assemblages attributed to the Acheulean have been reported from as early as circa 1.6–1.75 Ma, the characteristics of these earliest occurrences and comparisons with later assemblages have not been reported in detail. Here, we provide a newly established chronometric calibration for the Acheulean assemblages of the Konso Formation, southern Ethiopia, which span the time period ∼1.75 to <1.0 Ma. The earliest Konso Acheulean is chronologically indistinguishable from the assemblage recently published as the world’s earliest with an age of ∼1.75 Ma at Kokiselei, west of Lake Turkana, Kenya. This Konso assemblage is characterized by a combination of large picks and crude bifaces/unifaces made predominantly on large flake blanks. An increase in the number of flake scars was observed within the Konso Formation handaxe assemblages through time, but this was less so with picks. The Konso evidence suggests that both picks and handaxes were essential components of the Acheulean from its initial stages and that the two probably differed in function. The temporal refinement seen, especially in the handaxe forms at Konso, implies enhanced function through time, perhaps in processing carcasses with long and stable cutting edges. The documentation of the earliest Acheulean at ∼1.75 Ma in both northern Kenya and southern Ethiopia suggests that behavioral novelties were being established in a regional scale at that time, paralleling the emergence of Homo erectus-like hominid morphology. PMID:23359714

  18. Earth’s earliest evolved crust generated in an Iceland-like setting

    NASA Astrophysics Data System (ADS)

    Reimink, Jesse R.; Chacko, Thomas; Stern, Richard A.; Heaman, Larry M.

    2014-07-01

    It is unclear how the earliest continental crust formed on an Earth that was probably originally surfaced with oceanic crust. Continental crust may have first formed in an ocean island-like setting, where upwelling mantle generates magmas that crystallize to form new crust. Of the oceanic plateaux, Iceland is closest in character to continental crust, because its crust is anomalously thick and contains a relatively high proportion of silica-rich (sialic) rocks. Iceland has therefore been considered a suitable analogue for the generation of Earth’s earliest continental crust. However, the geochemical signature of sialic rocks from Iceland is distinct from the typical 3.9- to 2.5-billion-year-old Archaean rocks discovered so far. Here we report the discovery of an exceptionally well-preserved, 4.02-billion-year-old tonalitic gneiss rock unit within the Acasta Gneiss Complex in Canada. We use geochemical analyses to show that this rock unit is characterized by iron enrichment, negative Europium anomalies, unfractionated rare-earth-element patterns, and magmatic zircons with low oxygen isotope ratios. These geochemical characteristics are unlike typical Archaean igneous rocks, but are strikingly similar to those of the sialic rocks from Iceland and imply that this ancient rock unit was formed by shallow-level magmatic processes that include assimilation of rocks previously altered by surface waters. Our data provide direct evidence that Earth’s earliest continental crust formed in a tectonic setting comparable to modern Iceland.

  19. Myoblasts and myoblast-conditioned medium attract the earliest spinal neurites from frog embryos.

    PubMed Central

    McCaig, C D

    1986-01-01

    A study was made of the capacity of newly segmented somites, unsegmented mesoderm and medium conditioned by each of these tissues to attract the growth of the earliest spinal neurites from the neural tube of Xenopus laevis in tissue culture. When presented with segmented somitic myoblasts or sheets of skin, spinal neurites grew selectively towards the somitic myoblasts. Neurites were not attracted specifically to somitic myoblasts from their own rostrocaudal level. A variable proportion of myoblasts from unsegmented caudal mesoderm differentiated and elongated in co-culture with neural tube and skin. These myoblasts also attracted neural outgrowths, but only if present in sufficient numbers. An agar slab containing medium conditioned by the presence of segmented myoblasts for 1 day attracted neurite outgrowths. A source of medium conditioned by the presence of undifferentiated, unsegmented myotomal mesoderm alone did not attract neurite outgrowths. Nerve growth factor (NGF) at a range of concentrations in the agar source (500-10,000 ng/ml) did not attract the earliest neurite outgrowths. It is concluded that the earliest skeletal myoblasts from Xenopus laevis embryos may attract neural outgrowths by releasing a soluble factor. Myoblasts may have to develop to the stage of somite segmentation before secretion of such an agent begins. The release of a myoblast-derived factor so early in development may assist directed nerve growth in vivo. Images Plate 1 Plate 2 PMID:3795063

  20. Investigating the Disney Effect: Are Students Reluctant To Apply Natural Selection Principles to Life Forms with Which They Identify?

    ERIC Educational Resources Information Center

    Jensen, Murray; And Others

    This study was designed to investigate whether a student's responses to test questions about natural selection were influenced by the extent of the student's identification with the organism. The hypothesis was that a student would be reluctant to invoke the ravages of natural selection upon species with which they possessed a greater empathy than…

  1. Niche-driven evolution of metabolic and life-history strategies in natural and domesticated populations of Saccharomyces cerevisiae

    PubMed Central

    2009-01-01

    Background Variation of resource supply is one of the key factors that drive the evolution of life-history strategies, and hence the interactions between individuals. In the yeast Saccharomyces cerevisiae, two life-history strategies related to different resource utilization have been previously described in strains from different industrial origins. In this work, we analyzed metabolic traits and life-history strategies in a broader collection of yeast strains sampled in various ecological niches (forest, human body, fruits, laboratory and industrial environments). Results By analysing the genetic and plastic variation of six life-history and three metabolic traits, we showed that S. cerevisiae populations harbour different strategies depending on their ecological niches. On one hand, the forest and laboratory strains, referred to as extreme "ants", reproduce quickly, reach a large carrying capacity and a small cell size in fermentation, but have a low reproduction rate in respiration. On the other hand, the industrial strains, referred to as extreme "grasshoppers", reproduce slowly, reach a small carrying capacity but have a big cell size in fermentation and a high reproduction rate in respiration. "Grasshoppers" have usually higher glucose consumption rate than "ants", while they produce lower quantities of ethanol, suggesting that they store cell resources rather than secreting secondary products to cross-feed or poison competitors. The clinical and fruit strains are intermediate between these two groups. Conclusions Altogether, these results are consistent with a niche-driven evolution of S. cerevisiae, with phenotypic convergence of populations living in similar habitat. They also revealed that competition between strains having contrasted life-history strategies ("ants" and "grasshoppers") seems to occur at low frequency or be unstable since opposite life-history strategies appeared to be maintained in distinct ecological niches. PMID:20028531

  2. Kaposiform hemangioendothelioma with Kasabach-Merritt phenomenon in a neonate of life- and limb-threatening nature: A case report

    PubMed Central

    Subash, Anoop; Senthil, Ganesh K.; Ramamoorthy, Ramkumar; Appasamy, Andal; Selvarajan, Namasivayam

    2015-01-01

    Kaposiform hemangioendothelioma involving whole of a leg in a neonate with Kasabach-Merritt phenomenon causing limb and life-threatening situation has not been reported. One such case and its successful management is presented in this case report. Literature review is made. PMID:26628813

  3. Kaposiform hemangioendothelioma with Kasabach-Merritt phenomenon in a neonate of life- and limb-threatening nature: A case report.

    PubMed

    Subash, Anoop; Senthil, Ganesh K; Ramamoorthy, Ramkumar; Appasamy, Andal; Selvarajan, Namasivayam

    2015-01-01

    Kaposiform hemangioendothelioma involving whole of a leg in a neonate with Kasabach-Merritt phenomenon causing limb and life-threatening situation has not been reported. One such case and its successful management is presented in this case report. Literature review is made. PMID:26628813

  4. Rearing in natural and recovering tidal wetlands enhances growth and life-history diversity of Columbia Estuary tributary coho salmon Oncorhynchus kisutch population.

    PubMed

    Craig, B E; Simenstad, C A; Bottom, D L

    2014-07-01

    This study provides evidence of the importance of tributary tidal wetlands to local coho salmon Oncorhynchus kisutch populations and life-history diversity. Subyearling and, to a lesser extent, yearling O. kisutch life histories utilized various estuary habitats within the Grays River, a tidal freshwater tributary of the Columbia River estuary, including restoring emergent wetlands and natural forested wetlands. Migration timing data, size distributions, estuary residence and scale patterns suggest a predominance of subyearling migrant life histories, including several that involve extended periods of estuary rearing. Estuarine-rearing subyearling O. kisutch exhibited the greatest overall growth rates; the highest growth rates were seen in fish that utilized restoring emergent wetlands. These results contrast with studies conducted in the main-stem Columbia River estuary, which captured few O. kisutch, of which nearly all were hatchery-origin yearling smolts. Restoration and preservation of peripheral and tributary wetland habitats, such as those in the Grays River, could play an important role in the recovery of natural O. kisutch populations in the Columbia River and elsewhere. PMID:24890886

  5. Can switching fuels save water? A life cycle quantification of freshwater consumption for Texas coal- and natural gas-fired electricity

    NASA Astrophysics Data System (ADS)

    Grubert, Emily A.; Beach, Fred C.; Webber, Michael E.

    2012-12-01

    Thermal electricity generation is a major consumer of freshwater for cooling, fuel extraction and air emissions controls, but the life cycle water impacts of different fossil fuel cycles are not well understood. Much of the existing literature relies on decades-old estimates for water intensity, particularly regarding water consumed for fuel extraction. This work uses contemporary data from specific resource basins and power plants in Texas to evaluate water intensity at three major stages of coal and natural gas fuel cycles: fuel extraction, power plant cooling and power plant emissions controls. In particular, the water intensity of fuel extraction is quantified for Texas lignite, conventional natural gas and 11 unconventional natural gas basins in Texas, including major second-order impacts associated with multi-stage hydraulic fracturing. Despite the rise of this water-intensive natural gas extraction method, natural gas extraction appears to consume less freshwater than coal per unit of energy extracted in Texas because of the high water intensity of Texas lignite extraction. This work uses new resource basin and power plant level water intensity data to estimate the potential effects of coal to natural gas fuel switching in Texas’ power sector, a shift under consideration due to potential environmental benefits and very low natural gas prices. Replacing Texas’ coal-fired power plants with natural gas combined cycle plants (NGCCs) would reduce annual freshwater consumption in the state by an estimated 53 billion gallons per year, or 60% of Texas coal power’s water footprint, largely due to the higher efficiency of NGCCs.

  6. The earliest neuronal responses to hypoxia in the neocortical circuit are glutamate-dependent.

    PubMed

    Revah, Omer; Lasser-Katz, Efrat; Fleidervish, Ilya A; Gutnick, Michael J

    2016-11-01

    Soon after exposure to hypoxia or ischemia, neurons in cortical tissues undergo massive anoxic depolarization (AD). This precipitous event is preceded by more subtle neuronal changes, including enhanced excitatory and inhibitory synaptic transmitter release. Here, we have used patch-in-slice techniques to identify the earliest effects of acute hypoxia on the synaptic and intrinsic properties of Layer 5 neurons, to determine their time course and to evaluate the role of glutamate receptors in their generation. Coronal slices of mouse somatosensory cortex were maintained at 36°C in an interface chamber and challenged with episodes of hypoxia. In recordings with cell-attached electrodes, the open probability of Ca(2+)-dependent BK channels began to increase within seconds of hypoxia onset, indicating a sharp rise in [Ca(2+)]i just beneath the membrane. By using a high concentration of K(+) in the pipette, we simultaneously monitored the membrane potential and showed that the [Ca(2+)]i rise was not associated with membrane depolarization. The earliest hypoxia-induced synaptic disturbance was a marked increase in the frequency of sPSCs, which also began soon after the removal of oxygen and long before AD. This synaptic effect was accompanied by depletion of the readily releasable transmitter pools, as demonstrated by a decreased response to hyperosmotic solutions. The early [Ca(2+)]i rise, the early increase in transmitter release and the subsequent AD itself were all prevented by bathing in a cocktail containing blockers of ionotropic glutamate receptors. We found no evidence for involvement of pannexin hemichannels or TRPM7 channels in the early responses to hypoxia in this experimental preparation. Our data indicate that the earliest cellular consequences of cortical hypoxia are triggered by activation of glutamate-gated channels. PMID:27443966

  7. Postcranial skeletal pneumaticity and air-sacs in the earliest pterosaurs

    PubMed Central

    Butler, Richard J.; Barrett, Paul M.; Gower, David J.

    2009-01-01

    Patterns of postcranial skeletal pneumatization (PSP) indicate that pterosaurs possessed components of a bird-like respiratory system, including a series of ventilatory air-sacs. However, the presence of PSP in the oldest known pterosaurs has not been unambiguously demonstrated by previous studies. Here we provide the first unequivocal documentation of PSP in Late Triassic and earliest Jurassic pterosaurs. This demonstrates that PSP and, by inference, air-sacs were probably present in the common ancestor of almost all known pterosaurs, and has broader implications for the evolution of respiratory systems in bird-line archosaurs, including dinosaurs. PMID:19411265

  8. Earliest tea as evidence for one branch of the Silk Road across the Tibetan Plateau.

    PubMed

    Lu, Houyuan; Zhang, Jianping; Yang, Yimin; Yang, Xiaoyan; Xu, Baiqing; Yang, Wuzhan; Tong, Tao; Jin, Shubo; Shen, Caiming; Rao, Huiyun; Li, Xingguo; Lu, Hongliang; Fuller, Dorian Q; Wang, Luo; Wang, Can; Xu, Deke; Wu, Naiqin

    2016-01-01

    Phytoliths and biomolecular components extracted from ancient plant remains from Chang'an (Xi'an, the city where the Silk Road begins) and Ngari (Ali) in western Tibet, China, show that the tea was grown 2100 years ago to cater for the drinking habits of the Western Han Dynasty (207BCE-9CE), and then carried toward central Asia by ca.200CE, several hundred years earlier than previously recorded. The earliest physical evidence of tea from both the Chang'an and Ngari regions suggests that a branch of the Silk Road across the Tibetan Plateau, was established by the second to third century CE. PMID:26738699

  9. Earliest tea as evidence for one branch of the Silk Road across the Tibetan Plateau

    PubMed Central

    Lu, Houyuan; Zhang, Jianping; Yang, Yimin; Yang, Xiaoyan; Xu, Baiqing; Yang, Wuzhan; Tong, Tao; Jin, Shubo; Shen, Caiming; Rao, Huiyun; Li, Xingguo; Lu, Hongliang; Fuller, Dorian Q.; Wang, Luo; Wang, Can; Xu, Deke; Wu, Naiqin

    2016-01-01

    Phytoliths and biomolecular components extracted from ancient plant remains from Chang’an (Xi’an, the city where the Silk Road begins) and Ngari (Ali) in western Tibet, China, show that the tea was grown 2100 years ago to cater for the drinking habits of the Western Han Dynasty (207BCE-9CE), and then carried toward central Asia by ca.200CE, several hundred years earlier than previously recorded. The earliest physical evidence of tea from both the Chang’an and Ngari regions suggests that a branch of the Silk Road across the Tibetan Plateau, was established by the second to third century CE. PMID:26738699

  10. Pulses of middle Eocene to earliest Oligocene climatic deterioration in southern California and the Gulf Coast

    USGS Publications Warehouse

    Frederiksen, N.O.

    1991-01-01

    A general deterioration of terrestrial climate took place during middle Eocene to earliest Oligocene time in southern California and in the Gulf Coast. Pollen data, calibrated by calcareous nannofossil ages, indicate four events of rapid floral and/or vegetational change among angiosperms during this time interval. The events can be correlated between the two regions even though these regions lay within different floristic provinces, and each event of angiosperm change is interpreted to indicate a pulse of rapid climatic shift. The most distinct of these events is the Middle Eocene Diversity Decline, which resulted from a peak in last appearances (extinctions, emigrations) centered in the early Bartonian. -from Author