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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. Multiple roles for the endocannabinoid system during the earliest stages of life: pre- and postnatal development.

    PubMed

    Fride, E

    2008-05-01

    The endocannabinoid system, including its receptors (CB(1) and CB(2)), endogenous ligands ('endocannabinoids'), synthesising and degrading enzymes, as well as transporter molecules, has been detected from the earliest stages of embryonic development and throughout pre- and postnatal development. In addition, the endocannabinoids, notably 2-arachidonyl glycerol, are also present in maternal milk. During three distinct developmental stages (i.e. embryonic implantation, prenatal brain development and postnatal suckling), the endocannabinoid system appears to play an essential role for development and survival. Thus, during early pregnancy, successful embryonic passage through the oviduct and implantation into the uterus both require critical enzymatic control of optimal anandamide levels at the appropriate times and sites. During foetal life, the cannabinoid CB(1) receptor plays a major role in brain development, regulating neural progenitor differentiation into neurones and glia and guiding axonal migration and synaptogenesis. Postnatally, CB(1) receptor blockade interferes with the initiation of milk suckling in mouse pups, by inducing oral motor weakness, which exposes a critical role for CB(1) receptors in the initiation of milk suckling by neonates, possibly by interfering with innervation of the tongue muscles. Manipulating the endocannabinoid system by pre- and/or postnatal administration of cannabinoids or maternal marijuana consumption, has significant, yet subtle effects on the offspring. Thus, alterations in the dopamine, GABA and endocannabinoid systems have been reported while enhanced drug seeking behaviour and impaired executive (prefrontal cortical) function have also been observed. The relatively mild nature of the disruptive effects of prenatal cannabinoids may be understood in the framework of the intricate timing requirements and frequently biphasic effects of the (endo)cannabinoids. In conclusion, the endocannabinoid system plays several key roles

  3. Critical role of spatial information from chiral-asymmetric peptides in the earliest occurrence of life

    NASA Astrophysics Data System (ADS)

    Cruz-Rosas, Hugo I.; Riquelme, Francisco; Maldonado, Mariel; Cocho, Germinal

    2017-01-01

    The earliest functional living system on Earth should have been able to reproduce an ordered configuration and a self-organization dynamics. It was capable of resisting a random variability in time and space to keep the functionality. Amino acids (AAs) and nucleobases generated from abiotic reactions as seen in laboratory-based experiments have demonstrated that molecular elements for life can be obtained by predictable physicochemical processes. However, a functional, self-organized living system needs complex molecular interactions to endure. In this paper, we address the transference of spatial information on highly enantiopure polymers as a critical condition to support the dynamics in a self-organized biogenic system. Previous scenarios have considered almost exclusively the information encoded in sequences as the suitable source of prebiotic information. But the spatial information transference has been poorly understood thus far. We provide the supporting statements which predict that the ordered configuration in a biogenic system should be significantly influenced by spatial information, instead of being exclusively generated by sequences of polymers. This theoretical approach takes into consideration that the properties of mutation and inheritance did not develop before definition of the structures that allow the management of information. Rather, we postulate that the molecular structures to store and transfer information must exist at first, in order to retain particular functional `meaning', and subsequently, such information can be `inherited' and eventually modified. Thus, the present contribution follows the theory that life was originated from an unstable prebiotic environment that involves the early spatial information transference based on large chiral asymmetry.

  4. 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

  5. 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

  6. 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.

  7. 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

  8. 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.

  9. 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.

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

    PubMed

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

    2007-04-10

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

  11. 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.

  12. 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

  13. Australia's earliest planispheres

    NASA Astrophysics Data System (ADS)

    Orchiston, W.

    2003-12-01

    Australia's earliest-known planispheres were made by a Sydney amateur astronomer named George Butterfield in 1870 and 1877, although a similar but more crudely-made 'noctural dial' was created by Philip Parker King in 1852. This paper discusses these pioneering endeavours, other nineteenth century attempts to popularise astronomy, and the prevailing astronomical climate in Australia at that time.

  14. The earliest known reptile

    NASA Astrophysics Data System (ADS)

    Smithson, T. R.

    1989-12-01

    AMNIOTES (reptiles, birds and mammals) are distinguished from non-amniote tetrapods (amphibians) by the presence of complex embryonic membranes. One of these, the amnion, gives its name to the group. Very few skeletal characters distinguish amniotes from amphibians1, making it difficult to recognize early amniotes in the fossil record. The earliest amniote fossil identified so far is Hylonomus from the Westphalian (Upper Carboniferous) of Joggins, Nova Scotia2,3, (~300 Myr). I report here the discovery of a much earlier amniote skeleton from the Brigantian (Lower Carboniferous) of Scotland (~338 Myr) 4, which thus represents the earliest occurrence of amniotes in the fossil record. The specimen was collected from the East Kirkton Limestone, near Bathgate, West Lothian4-8, and is part of a unique terrestrial fauna that includes eurypterids, myriapods, scorpions and the earliest-known harvestman spider7,9, together with the earliest known temno-spondyls, a group that may include the ancestors of all living amphibians10. It will make an important contribution to our knowledge of early amniote morphology and the interrelationships of tetrapods.

  15. 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.

  16. 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

  17. Pox Pottery: Earliest Identified Mexican Ceramic.

    PubMed

    Brush, C F

    1965-07-09

    The earliest known ceramics from Mexico, termed "Pox Pottery," may mark the transition from a nomadic to a settled way of life. The presence of "Pox Pottery" in both coastal Guerrero and the Tehuacan Valley might provide evidence as to the type of environment in which this change first occurred.

  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. 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.

  20. 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

  1. 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

  2. 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

    2014-08-07

    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.

  3. 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…

  4. The habitat and nature of early life.

    PubMed

    Nisbet, E G; Sleep, N H

    2001-02-22

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

  5. Earth's earliest atmospheres.

    PubMed

    Zahnle, Kevin; Schaefer, Laura; Fegley, Bruce

    2010-10-01

    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.

  6. 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.

  7. The earliest seeds

    USGS Publications Warehouse

    Gillespie, W.H.; Rothwell, G.W.; Scheckler, S.E.

    1981-01-01

    Lagenostomalean-type seeds in bifurcating cupule systems have been discovered in the late Devonian Hampshire Formation of Randolph County, West Virginia, USA (Fig. 1). The associated megaflora, plants from coal balls, and vertebrate and invertebrate faunas demonstrate that the material is Famennian; the microflora indicates a more specific Fa2c age. Consequently, these seeds predate Archaeosperma arnoldii1 from the Fa2d of northeastern Pennsylvania, the oldest previously reported seed. By applying precision fracture, transfer, de??gagement, and thin-section techniques to selected cupules from the more than 100 specimens on hand, we have determined the three-dimensional morphology and histology of the seeds (Fig. 2a-h, k) and cupule systems. A comparison with known late Devonian to early Carboniferous seeds reveals that ours are more primitively organized than all except Genomosperma2,3. ?? 1981 Nature Publishing Group.

  8. 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

  9. 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.

  10. 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.

  11. The earliest known sauropod dinosaur.

    PubMed

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

    2000-09-07

    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.

  12. 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

  13. The role of natural selection in the origin of life.

    PubMed

    Fry, Iris

    2011-02-01

    It is commonly accepted among origin-of-life scientists that the emergence of life was an evolutionary process involving at one stage or other the working of natural selection. Researchers disagree, however, on the nature of the chemical infrastructure that could have formed prebiotically, enabling the evolutionary process. The division of the origin-of-life research community into 'geneticists' and 'metabolists' usually revolves around the issue whether the first to arise prebiotically was a genetic polymer or a primitive metabolic system. In this paper I offer an alternative classification based on the attitude to the onset of natural selection. From this perspective I add to the conventional division between gene-first and metabolism-first groups a position I call "preparatory metabolism". By this line of thought, an RNA or an RNA-like polymer could not have emerged prebiotically. Nevertheless, the onset of natural selection had to wait until such a polymer had arised. This paper examines the RNA-first, RNA-later, metabolism-first and preparatory-metabolism scenarios, assessing the weaknesses and strengths of each. I conclude that despite the recent theoretical advances in all these lines of research, and despite experimental breakthroughs, especially in overcoming several RNA-first hurdles, none of the examined paradigms has yet attained decisive experimental support. Demonstrating the evolvability of a potentially prebiotic infrastructure, whether genetic or metabolic, is a most serious challenge. So is the experimental demonstration of the emergence of such an infrastructure under prebiotic conditions. The current agenda before origin-of-life researchers of all stripes and colors is the search for the experimental means to tackle all these difficulties.

  14. 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.

  15. 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

  16. 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.

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

    PubMed

    Teaford, M F; Ungar, P S

    2000-12-05

    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.

  18. 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

  19. 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

  20. Oxygen requirements of the earliest animals

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    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.

  1. Oxygen requirements of the earliest animals.

    PubMed

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

    2014-03-18

    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.

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

    PubMed

    Powell, Russell; Mariscal, Carlos

    2015-12-06

    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.

  3. Life care planning: a natural domain of physiatry.

    PubMed

    Gonzales, Joe G; Zotovas, Andrea

    2014-02-01

    This article is an introduction to life care planning and its relevance to physiatry and physiatric practice. It includes a discussion of life care planning, physiatry's role within its history and evolution, and life care planning methodologies. It also discusses life care planning education and certification, how the core competencies of the physiatrist are particularly relevant and applicable to life care planning, and life care planning's capacity to complement and diversify a clinical physiatric practice.

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

    PubMed Central

    Powell, Russell; Mariscal, Carlos

    2015-01-01

    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

  5. The Search for Life on Other Planets

    NASA Astrophysics Data System (ADS)

    Jakosky, Bruce

    1998-10-01

    1. The search for life in the universe; 2. Impacts, extinctions, and the earliest history of life on Earth; 3. The history of the Earth; 4. The Earth's geological record and the earliest life; 5. Energy and life in unique environments on Earth; 6. Origin of life on Earth; 7. Requirements for extraterrestrial life; 8. Is life on Mars possible?; 9. Possible fossil life in meteorites from Mars; 10. Implanting life on Mars; 11. The exobiology of Venus; 12. Titan - a natural exobiology laboratory?; 13. Exobiology in the Jupiter system; 14. Formation of planets around other stars; 15. Searching for planets around other stars; 16. The habitability of planets around other stars; 17. Intelligent life in the universe; 18. Life in the universe; Additional reading and bibliography; Index.

  6. 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

  7. 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

  8. 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.

  9. 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…

  10. The nature of life-transforming changes among cancer survivors.

    PubMed

    Skeath, Perry; Norris, Shanti; Katheria, Vani; White, Jonathan; Baker, Karen; Handel, Dan; Sternberg, Esther; Pollack, John; Groninger, Hunter; Phillips, Jayne; Berger, Ann

    2013-09-01

    Some cancer survivors report positive subjective changes they describe as "life transforming." We used a grounded theory approach to identify the content, underlying process, and identifying characteristics of self-defined "life-transforming" changes (LTCs) reported by 9 cancer survivors. To actualize their hopes for improvement, participants used a self-guided process centered on pragmatic action: researching options, gaining experience, and frankly evaluating results. Many participants discovered unanticipated personal abilities and resources, and those became highly useful in coping with other challenges apart from cancer. This made the increased personal abilities and resources "life transforming" rather than being substantially limited to reducing cancer-related problems. The action-oriented features and processes of LTCs seemed to be more fully described by experiential learning theory than by posttraumatic growth and coping. Supportive intervention to facilitate positive change processes could decrease suffering and enhance positive psychosocial and spiritual outcomes for cancer survivors.

  11. The earliest record of human activity in northern Europe

    NASA Astrophysics Data System (ADS)

    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.

    2005-12-01

    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 780kyr ago) and Ceprano, Italy (about 800kyr ago) show that early Homo had dispersed to the Mediterranean hinterland before the Brunhes-Matuyama magnetic polarity reversal (780kyr ago). Until now, the earliest uncontested artefacts from northern Europe were much younger, suggesting that humans were unable to colonize northern latitudes until about 500kyr ago. Here we report flint artefacts from the Cromer Forest-bed Formation at Pakefield (52°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 700kyr ago) and thus represent the earliest unequivocal evidence for human presence north of the Alps.

  12. 29 CFR 4022.10 - Earliest PBGC Retirement Date.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 9 2011-07-01 2011-07-01 false Earliest PBGC Retirement Date. 4022.10 Section 4022.10... § 4022.10 Earliest PBGC Retirement Date. The Earliest PBGC Retirement Date for a participant is the...)(B) of ERISA. The Earliest PBGC Retirement Date is determined in accordance with this § 4022.10....

  13. 29 CFR 4022.10 - Earliest PBGC Retirement Date.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 9 2014-07-01 2014-07-01 false Earliest PBGC Retirement Date. 4022.10 Section 4022.10... § 4022.10 Earliest PBGC Retirement Date. The Earliest PBGC Retirement Date for a participant is the...)(B) of ERISA. The Earliest PBGC Retirement Date is determined in accordance with this § 4022.10....

  14. 29 CFR 4022.10 - Earliest PBGC Retirement Date.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 9 2013-07-01 2013-07-01 false Earliest PBGC Retirement Date. 4022.10 Section 4022.10... § 4022.10 Earliest PBGC Retirement Date. The Earliest PBGC Retirement Date for a participant is the...)(B) of ERISA. The Earliest PBGC Retirement Date is determined in accordance with this § 4022.10....

  15. 29 CFR 4022.10 - Earliest PBGC Retirement Date.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Earliest PBGC Retirement Date. 4022.10 Section 4022.10... § 4022.10 Earliest PBGC Retirement Date. The Earliest PBGC Retirement Date for a participant is the...)(B) of ERISA. The Earliest PBGC Retirement Date is determined in accordance with this § 4022.10....

  16. 29 CFR 4022.10 - Earliest PBGC Retirement Date.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 9 2012-07-01 2012-07-01 false Earliest PBGC Retirement Date. 4022.10 Section 4022.10... § 4022.10 Earliest PBGC Retirement Date. The Earliest PBGC Retirement Date for a participant is the...)(B) of ERISA. The Earliest PBGC Retirement Date is determined in accordance with this § 4022.10....

  17. 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…

  18. 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…

  19. 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.

  20. 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…

  1. Comparing life history characteristics of Lake Michigan’s naturalized and stocked Chinook Salmon

    USGS Publications Warehouse

    Kerns, Janice A; Rogers, Mark W.; Bunnell, David; Claramunt, Randall M.; Collingsworth, Paris D.

    2016-01-01

    Lake Michigan supports popular fisheries for Chinook Salmon Oncorhynchus tshawytscha that have been sustained by stocking since the late 1960s. Natural recruitment of Chinook Salmon in Lake Michigan has increased in the past few decades and currently contributes more than 50% of Chinook Salmon recruits. We hypothesized that selective forces differ for naturalized populations born in the wild and hatchery populations, resulting in divergent life history characteristics with implications for Chinook Salmon population production and the Lake Michigan fishery. First, we conducted a historical analysis to determine if life history characteristics changed through time as the Chinook Salmon population became increasingly naturalized. Next, we conducted a 2-year field study of naturalized and hatchery stocked Chinook Salmon spawning populations to quantify differences in fecundity, egg size, timing of spawning, and size at maturity. In general, our results did not indicate significant life history divergence between naturalized and hatchery-stocked Chinook Salmon populations in Lake Michigan. Although historical changes in adult sex ratio were correlated with the proportion of naturalized individuals, changes in weight at maturity were better explained by density-dependent factors. The field study revealed no divergence in fecundity, timing of spawning, or size at maturity, and only small differences in egg size (hatchery > naturalized). For the near future, our results suggest that the limited life history differences observed between Chinook Salmon of naturalized and hatchery origin will not lead to large differences in characteristics important to the dynamics of the population or fishery.

  2. 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.

  3. Cacao usage by the earliest Maya civilization.

    PubMed

    Hurst, W Jeffrey; Tarka, Stanley M; Powis, Terry G; Valdez, Fred; Hester, Thomas R

    2002-07-18

    The Maya archaeological site at Colha in northern Belize, Central America, has yielded several spouted ceramic vessels that contain residues from the preparation of food and beverages. Here we analyse dry residue samples by using high-performance liquid chromatography coupled to atmospheric-pressure chemical-ionization mass spectrometry, and show that chocolate (Theobroma cacao) was consumed by the Preclassic Maya as early as 600 bc, pushing back the earliest chemical evidence of cacao use by some 1,000 years. Our application of this new and highly sensitive analytical technique could be extended to the identification of other ancient foods and beverages.

  4. 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.

  5. Vertebral architecture in the earliest stem tetrapods.

    PubMed

    Pierce, Stephanie E; Ahlberg, Per E; Hutchinson, John R; Molnar, Julia L; Sanchez, Sophie; Tafforeau, Paul; Clack, Jennifer A

    2013-02-14

    The construction of the vertebral column has been used as a key anatomical character in defining and diagnosing early tetrapod groups. Rhachitomous vertebrae--in which there is a dorsally placed neural arch and spine, an anteroventrally placed intercentrum and paired, posterodorsally placed pleurocentra--have long been considered the ancestral morphology for tetrapods. Nonetheless, very little is known about vertebral anatomy in the earliest stem tetrapods, because most specimens remain trapped in surrounding matrix, obscuring important anatomical features. Here we describe the three-dimensional vertebral architecture of the Late Devonian stem tetrapod Ichthyostega using propagation phase-contrast X-ray synchrotron microtomography. Our scans reveal a diverse array of new morphological, and associated developmental and functional, characteristics, including a possible posterior-to-anterior vertebral ossification sequence and the first evolutionary appearance of ossified sternal elements. One of the most intriguing features relates to the positional relationships between the vertebral elements, with the pleurocentra being unexpectedly sutured or fused to the intercentra that directly succeed them, indicating a 'reverse' rhachitomous design. Comparison of Ichthyostega with two other stem tetrapods, Acanthostega and Pederpes, shows that reverse rhachitomous vertebrae may be the ancestral condition for limbed vertebrates. This study fundamentally revises our current understanding of vertebral column evolution in the earliest tetrapods and raises questions about the presumed vertebral architecture of tetrapodomorph fish and later, more crownward, tetrapods.

  6. 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…

  7. 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

  8. Rethinking the area of protection "natural resources" in life cycle assessment.

    PubMed

    Dewulf, Jo; Benini, Lorenzo; Mancini, Lucia; Sala, Serenella; Blengini, Gian Andrea; Ardente, Fulvio; Recchioni, Marco; Maes, Joachim; Pant, Rana; Pennington, David

    2015-05-05

    Life cycle impact assessment (LCIA) in classical life cycle assessment (LCA) aims at analyzing potential impacts of products and services typically on three so-called areas of protection (AoPs): Natural Environment, Human Health, and Natural Resources. This paper proposes an elaboration of the AoP Natural Resources. It starts with analyzing different perspectives on Natural Resources as they are somehow sandwiched in between the Natural Environment (their cradle) and the human-industrial environment (their application). Reflecting different viewpoints, five perspectives are developed with the suggestion to select three in function of classical LCA. They result in three safeguard subjects: the Asset of Natural Resources, their Provisioning Capacity, and their role in Global Functions. Whereas the Provisioning Capacity is fully in function of humans, the global functions go beyond provisioning as they include nonprovisioning functions for humans and regulating and maintenance services for the globe as a whole, following the ecosystem services framework. A fourth and fifth safeguard subject has been identified: recognizing the role Natural Resources for human welfare, either specifically as building block in supply chains of products and services as such, either with or without their functions beyond provisioning. But as these are far broader as they in principle should include characterization of mechanisms within the human industrial society, they are considered as subjects for an integrated sustainability assessment (LCSA: life cycle sustainability assessment), that is, incorporating social, economic and environmental issues.

  9. 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.

  10. 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.

  11. 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.

  12. 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... sand, gravel or minerals, corals, sea feathers and fans, shells and shell fish starfishes or other... this Preserve. No rope, wire or other contrivance shall be attached to any coral, rock or...

  13. 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... sand, gravel or minerals, corals, sea feathers and fans, shells and shell fish starfishes or other... this Preserve. No rope, wire or other contrivance shall be attached to any coral, rock or...

  14. 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... sand, gravel or minerals, corals, sea feathers and fans, shells and shell fish starfishes or other... this Preserve. No rope, wire or other contrivance shall be attached to any coral, rock or...

  15. 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... sand, gravel or minerals, corals, sea feathers and fans, shells and shell fish starfishes or other... this Preserve. No rope, wire or other contrivance shall be attached to any coral, rock or...

  16. 43 CFR 15.2 - Removal or destruction of natural features and marine life.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... LARGO CORAL REEF PRESERVE § 15.2 Removal or destruction of natural features and marine life. No person... sand, gravel or minerals, corals, sea feathers and fans, shells and shell fish starfishes or other... this Preserve. No rope, wire or other contrivance shall be attached to any coral, rock or...

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. Indy gene variation in natural populations confers fitness advantage and life span extension through transposon insertion.

    PubMed

    Zhu, Chen-Tseh; Chang, Chengyi; Reenan, Robert A; Helfand, Stephen L

    2014-01-01

    Natural selection acts to maximize reproductive fitness. However, antagonism between life span and reproductive success frequently poses a dilemma pitting the cost of fecundity against longevity. Here, we show that natural populations of Drosophila melanogaster harbor a Hoppel transposon insertion variant in the longevity gene Indy (I'm not dead yet), which confers both increased reproduction and longevity through metabolic changes. Heterozygosity for this natural long-lived variant has been maintained in isolates despite long-term inbreeding under laboratory conditions and advantageously confers increased fecundity. DNA sequences of variant chromosome isolates show evidence of selective sweep acting on the advantageous allele, suggesting that natural selection acts to maintain this variant. The transposon insertion also regulates Indy expression level, which has experimentally been shown to affect life span and fecundity. Thus, in the wild, evolution reaffirms that the mechanism of heterozygote advantage has acted upon the Indy gene to assure increased reproductive fitness and, coincidentally, longer life span through regulatory transposon mutagenesis.

  3. 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

  4. Earliest Holozoan Expansion of Phosphotyrosine Signaling

    PubMed Central

    Suga, Hiroshi; Torruella, Guifré; Burger, Gertraud; Brown, Matthew W.; Ruiz-Trillo, Iñaki

    2015-01-01

    Phosphotyrosine (pTyr) signaling is involved in development and maintenance of metazoans’ multicellular body through cell-to-cell communication. Tyrosine kinases (TKs), tyrosine phosphatases, and other proteins relaying the signal compose the cascade. Domain architectures of the pTyr signaling proteins are diverse in metazoans, reflecting their complex intercellular communication. Previous studies had shown that the metazoan-type TKs, as well as other pTyr signaling proteins, were already diversified in the common ancestor of metazoans, choanoflagellates, and filastereans (which are together included in the clade Holozoa) whereas they are absent in fungi and other nonholozoan lineages. However, the earliest-branching holozoans Ichthyosporea and Corallochytrea, as well as the two fungi-related amoebae Fonticula and Nuclearia, have not been studied. Here, we analyze the complete genome sequences of two ichthyosporeans and Fonticula, and RNAseq data of three additional ichthyosporeans, one corallochytrean, and Nuclearia. Both the ichthyosporean and corallochytrean genomes encode a large variety of receptor TKs (RTKs) and cytoplasmic TKs (CTKs), as well as other pTyr signaling components showing highly complex domain architectures. However, Nuclearia and Fonticula have no TK, and show much less diversity in other pTyr signaling components. The CTK repertoires of both Ichthyosporea and Corallochytrea are similar to those of Metazoa, Choanoflagellida, and Filasterea, but the RTK sets are totally different from each other. The complex pTyr signaling equipped with positive/negative feedback mechanism likely emerged already at an early stage of holozoan evolution, yet keeping a high evolutionary plasticity in extracellular signal reception until the co-option of the system for cell-to-cell communication in metazoans. PMID:24307687

  5. 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.

  6. 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.

  7. 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.

  8. Influence of natural extracts on the shelf life of modified atmosphere-packaged pork patties.

    PubMed

    Lorenzo, José M; Sineiro, Jorge; Amado, Isabel R; Franco, Daniel

    2014-01-01

    In this study four natural extracts from tea (TEA), grape (GRA), chestnut (CHE) and seaweed (SEA) with potential antioxidant activity were evaluated in pork patties. During 20 days of storage in modified atmosphere packs at 2°C, pH, colour, lipid oxidation and microbial spoilage parameters of raw minced porcine patties were examined and compared with a synthetic antioxidant (BHT) and control (CON) batch. Due to their higher polyphenol content, GRA and TEA extracts were the most effective antioxidants against lipid oxidation, also limiting colour deterioration. In addition, both natural extracts led to a decrease of total viable counts (TVC), lactic acid bacteria (LAB), Pseudomonas and psychotropic aerobic bacteria compared to the control. Among the four natural compounds tested, tea and grape extracts showed the most potential as alternatives to commercial antioxidants, for increasing the quality and extending the shelf-life of porcine patties.

  9. 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

  10. Urban-rural differences in children's earliest memories.

    PubMed

    Göz, İlyas; Çeven, Z İrem; Tekcan, Ali I

    2017-02-01

    The purpose of the present study was to address the effects of urban vs. rural upbringing on earliest autobiographical memories. We asked children (aged 10-13) brought up in an urban vs. in a rural setting to report their earliest memories. Earliest memories of children from rural areas were a year later than those of children from urban areas. Moreover, memories of children from rural areas were more likely to contain social interactions and tended to be less detailed compared to those from urban areas. The groups, however, were not different in specificity, autonomous orientation, or emotion. Results are discussed in the context of a social cultural developmental approach.

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

    PubMed

    Gawlik, Aneta; Hochberg, Ze'ev

    2012-06-19

    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.

  12. 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.

  13. 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

  14. 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

    2015-09-21

    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.

  15. 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.

  16. Early-life origin of adult disease: evidence from natural experiments.

    PubMed

    Vaiserman, Alexander

    2011-01-01

    Until the present time, disease susceptibility was believed to be determined solely by the genetic information carried in the DNA sequence. In recent years, however, it has become clear that epigenetic rearrangements play an equally essential role in the disease development and that this process, particularly at key developmental stages, is very susceptible to environmental modulations. The extensive studies, both human and animal, have shown that early-life environment is probably the most important causal component in the etiology of some diseases including cancer as well as metabolic and cardiovascular disorders. This review considers the natural experiment-based evidence regarding the developmental origin of human adult disease.

  17. Human Disturbance during Early Life Impairs Nestling Growth in Birds Inhabiting a Nature Recreation Area

    PubMed Central

    Remacha, Carolina; Delgado, Juan Antonio; Bulaic, Mateja; Pérez-Tris, Javier

    2016-01-01

    Nature recreation conflicts with conservation, but its impacts on wildlife are not fully understood. Where recreation is not regulated, visitors to natural areas may gather in large numbers on weekends and holidays. This may increase variance in fitness in wild populations, if individuals whose critical life cycle stages coincide with periods of high human disturbance are at a disadvantage. We studied nestling development of blue tits (Cyanistes caeruleus) in a natural area where recreation activities intensify during weekends and other public holidays at picnic and leisure facilities, but not in the surrounding woods. In nests located near recreation facilities, blue tit nestlings that hatched during holidays developed slowly, and fledged with low body mass and poor body condition. However, nestlings that hatched outside of holidays and weekends in these nest boxes developed normally, eventually attaining similar phenotypes as those hatching in the surrounding woods. Within-brood variance in body mass was also higher in broods that began growing during holidays in disturbed areas. Our results show that early disturbance events may have negative consequences for wild birds if they overlap with critical stages of development, unveiling otherwise cryptic impacts of human activities. These new findings may help managers better regulate nature recreation. PMID:27851816

  18. 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.

  19. Earliest land plants created modern levels of atmospheric oxygen

    PubMed Central

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

    2016-01-01

    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 (δ13C) 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

  20. Earliest land plants created modern levels of atmospheric oxygen

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

    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 (δ13C) 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.

  1. 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.

  2. 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

  3. Natural selection and quantitative genetics of life-history traits in Western women: a twin study.

    PubMed

    Kirk, K M; Blomberg, S P; Duffy, D L; Heath, A C; Owens, I P; Martin, N G

    2001-02-01

    Whether contemporary human populations are still evolving as a result of natural selection has been hotly debated. For natural selection to cause evolutionary change in a trait, variation in the trait must be correlated with fitness and be genetically heritable and there must be no genetic constraints to evolution. These conditions have rarely been tested in human populations. In this study, data from a large twin cohort were used to assess whether selection will cause a change among women in a contemporary Western population for three life-history traits: age at menarche, age at first reproduction, and age at menopause. We control for temporal variation in fecundity (the "baby boom" phenomenon) and differences between women in educational background and religious affiliation. University-educated women have 35% lower fitness than those with less than seven years education, and Roman Catholic women have about 20% higher fitness than those of other religions. Although these differences were significant, education and religion only accounted for 2% and 1% of variance in fitness, respectively. Using structural equation modeling, we reveal significant genetic influences for all three life-history traits, with heritability estimates of 0.50, 0.23, and 0.45, respectively. However, strong genetic covariation with reproductive fitness could only be demonstrated for age at first reproduction, with much weaker covariation for age at menopause and no significant covariation for age at menarche. Selection may, therefore, lead to the evolution of earlier age at first reproduction in this population. We also estimate substantial heritable variation in fitness itself, with approximately 39% of the variance attributable to additive genetic effects, the remainder consisting of unique environmental effects and small effects from education and religion. We discuss mechanisms that could be maintaining such a high heritability for fitness. Most likely is that selection is now acting on

  4. Primal eukaryogenesis: on the communal nature of precellular States, ancestral to modern life.

    PubMed

    Egel, Richard

    2012-01-23

    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.

  5. An improved calculation of the exergy of natural resources for exergetic life cycle assessment (ELCA).

    PubMed

    De Meester, Bram; Dewulf, Jo; Janssens, Arnold; Van Langenhove, Herman

    2006-11-01

    The focus in environmental research is shifting from emission abatement to critical process analysis, including assessment of resource consumption. The exergy theory offers a thermodynamic methodology to account for the consumption of natural resources. However, exergy data on mineral resources available in the literature are inadequate to apply to exergetic life cycle analysis, due to incompleteness, inconsistencies, and a dated thermochemical basis. An uncertainty assessment of the data has to be performed as well. In this work, three recent thermochemical databases were applied to evaluate the chemical exergy of 85 elements and 73 minerals, 21 of which had not yet been quantified in the literature. The process required the choice of a new reference species for aluminum. Muscovite was selected, giving rise to a chemical exergy of 809.4 kJ/mol for aluminum. The theory proved to be robust for the exergy of chemical elements, as exergy values differing by 1.2% on average from most recent literature were found. On the contrary, the exergy values for minerals differed by factors up to 14 from literature values, due to the application of recent thermochemical values and consistently selected reference species. The consistent dataset of this work will enable straightforward resource intake evaluation through an exergetic life cycle assessment.

  6. 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.

  7. 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

  8. 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

  9. Natural variation in developmental life-history traits of the bacterium Myxococcus xanthus.

    PubMed

    Kraemer, Susanne A; Toups, Melissa A; Velicer, Gregory J

    2010-08-01

    The soil bacterium Myxococcus xanthus is a model for the study of cooperative microbial behaviours such as social motility and fruiting body formation. Several M. xanthus developmental traits that are frequently quantified for laboratory strains are likely to be significant components of fitness in natural populations, yet little is known about the degree to which such traits vary in the wild and may therefore be subject to natural selection. Here, we have tested whether several key M. xanthus developmental life-history traits have diverged significantly among strains both from globally distant origins and from within a sympatric, centimetre-scale population. The isolates examined here were found to vary considerably, in a heritable manner, in their rate of developmental aggregation and in both their rate and efficiency of spore production. Isolates also varied in the nutrient-concentration threshold triggering spore formation and in the heat resistance of spores. The large diversity of developmental phenotypes documented here leads to questions regarding the relative roles of selection and genetic drift in shaping the diversity of local soil populations with respect to these developmental traits. It also raises the question of whether fitness in the wild is largely determined by traits that are expressed independent of social context or by behaviours that are expressed only in genetically heterogeneous social groups.

  10. Life cycle of Sarcocystis neurona in its natural intermediate host, the raccoon, Procyon lotor.

    PubMed

    Stanek, J F; Dubey, J P; Oglesbee, M J; Reed, S M; Lindsay, D S; Capitini, L A; Njoku, C J; Vittitow, K L; Saville, W J A

    2002-12-01

    Sarcocystis neurona causes encephalomyelitis in many species of mammals and is the most important cause of neurologic disease in the horse. Its complete life cycle is unknown, particularly its development and localization in the intermediate host. Recently, the raccoon (Procyon lotor) was recognized as a natural intermediate host of S. neurona. In the present study, migration and development of S. neurona was studied in 10 raccoons that were fed S. neurona sporocysts from experimentally infected opossums; 4 raccoons served as controls. Raccoons were examined at necropsy 1, 3, 5, 7, 10, 14, 15, 22, 37, and 77 days after feeding on sporocysts (DAFS). Tissue sections of most of the organs were studied histologically and reacted with anti-S. neurona-specific polyclonal rabbit serum in an immunohistochemical test. Parasitemia was demonstrated in peripheral blood of raccoons 3 and 5 DAFS. Individual zoites were seen in histologic sections of intestines of raccoons euthanized 1, 3, and 5 DAFS. Schizonts and merozoites were seen in many tissues 7 to 22 DAFS, particularly in the brain. Sarcocysts were seen in raccoons killed 22 DAFS. Sarcocysts at 22 DAFS were immature and seen only in skeletal muscle. Mature sarcocysts were seen in all skeletal samples, particularly in the tongue of the raccoon 77 DAFS; these sarcocysts were infective to laboratory-raised opossums. This is the first report of the complete development of S. neurona schizonts and sarcocysts in a natural intermediate host.

  11. Bringing dinosaurs back to life: exhibiting prehistory at the American Museum of Natural History.

    PubMed

    Rieppel, Lukas

    2012-09-01

    This essay examines the exhibition of dinosaurs at the American Museum of Natural History during the first two decades of the twentieth century. Dinosaurs provide an especially illuminating lens through which to view the history of museum display practices for two reasons: they made for remarkably spectacular exhibits; and they rested on contested theories about the anatomy, life history, and behavior of long-extinct animals to which curators had no direct observational access. The American Museum sought to capitalize on the popularity of dinosaurs while mitigating the risks of mounting an overtly speculative display by fashioning them into a kind of mixed-media installation made of several elements, including fossilized bone, shellac, iron, and plaster. The resulting sculptures provided visitors with a vivid and lifelike imaginative experience. At the same time, curators, who were anxious to downplay the speculative nature of mounted dinosaurs, drew systematic attention to the material connection that tied individual pieces of fossilized bone to the actual past. Freestanding dinosaurs can therefore be read to have functioned as iconic sculptures that self-consciously advertised their indexical content.

  12. 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

  13. 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…

  14. 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.

  15. 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)

  16. 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

  17. 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…

  18. Ultralong Cycle Life Achieved by a Natural Plant: Miscanthus × giganteus for Lithium Oxygen Batteries.

    PubMed

    Li, Shu; Bi, Xuanxuan; Tao, Ran; Wang, Qingzhen; Yao, Ying; Wu, Feng; Zhang, Cunzhong

    2017-02-08

    Large energy-storage systems and electric vehicles require energy devices with high power and high energy density. Lithium oxygen (Li-O2) batteries could achieve high energy density, but they are still facing problems such as low practical capacity and poor cyclability. Here, we prepare activated carbons (MGACs) based on the natural plant Miscanthus × giganteus (MG) through slow pyrolysis. It possesses a large surface area, plenty of active sites, and high porosity, which are beneficial to the utilization of oxygen electrode in Li-O2 batteries. The MGACs-based oxygen electrode delivers a high specific capacity of 9400 mAh/g at 0.02 mA/cm(2), and long cycle life of 601 cycles (with a cutoff capacity of 500 mAh/g) and 295 cycles (with a cutoff capacity of 1000 mAh/g) at 0.2 mA/cm(2), respectively. Additionally, the material exhibits high rate capability and high reversibility, which is a promising candidate for the application in Li-O2 batteries.

  19. Life-cycle greenhouse gas assessment of Nigerian liquefied natural gas addressing uncertainty.

    PubMed

    Safaei, Amir; Freire, Fausto; Henggeler Antunes, Carlos

    2015-03-17

    Natural gas (NG) has been regarded as a bridge fuel toward renewable sources and is expected to play a greater role in future global energy mix; however, a high degree of uncertainty exists concerning upstream (well-to-tank, WtT) greenhouse gas (GHG) emissions of NG. In this study, a life-cycle (LC) model is built to assess uncertainty in WtT GHG emissions of liquefied NG (LNG) supplied to Europe by Nigeria. The 90% prediction interval of GHG intensity of Nigerian LNG was found to range between 14.9 and 19.3 g CO2 eq/MJ, with a mean value of 16.8 g CO2 eq/MJ. This intensity was estimated considering no venting practice in Nigerian fields. The mean estimation can shift up to 25 g CO2 eq when considering a scenario with a higher rate of venting emissions. A sensitivity analysis of the time horizon to calculate GHG intensity was also performed showing that higher GHG intensity and uncertainty are obtained for shorter time horizons, due to the higher impact factor of methane. The uncertainty calculated for Nigerian LNG, specifically regarding the gap of data for methane emissions, recommends initiatives to measure and report emissions and further LC studies to identify hotspots to reduce the GHG intensity of LNG chains.

  20. 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

  1. 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

  2. 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…

  3. 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…

  4. The earliest fossil record of the animals and its significance.

    PubMed

    Budd, Graham E

    2008-04-27

    The fossil record of the earliest animals has been enlivened in recent years by a series of spectacular discoveries, including embryos, from the Ediacaran to the Cambrian, but many issues, not least of dating and interpretation, remain controversial. In particular, aspects of taphonomy of the earliest fossils require careful consideration before pronouncements about their affinities. Nevertheless, a reasonable case can now be made for the extension of the fossil record of at least basal animals (sponges and perhaps cnidarians) to a period of time significantly before the beginning of the Cambrian. The Cambrian explosion itself still seems to represent the arrival of the bilaterians, and many new fossils in recent years have added significant data on the origin of the three major bilaterian clades. Why animals appear so late in the fossil record is still unclear, but the recent trend to embrace rising oxygen levels as being the proximate cause remains unproven and may even involve a degree of circularity.

  5. Chemical and archaeological evidence for the earliest cacao beverages.

    PubMed

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

    2007-11-27

    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.

  6. 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

  7. Uncertainty in life cycle greenhouse gas emissions from United States natural gas end-uses and its effects on policy.

    PubMed

    Venkatesh, Aranya; Jaramillo, Paulina; Griffin, W Michael; Matthews, H Scott

    2011-10-01

    Increasing concerns about greenhouse gas (GHG) emissions in the United States have spurred interest in alternate low carbon fuel sources, such as natural gas. Life cycle assessment (LCA) methods can be used to estimate potential emissions reductions through the use of such fuels. Some recent policies have used the results of LCAs to encourage the use of low carbon fuels to meet future energy demands in the U.S., without, however, acknowledging and addressing the uncertainty and variability prevalent in LCA. Natural gas is a particularly interesting fuel since it can be used to meet various energy demands, for example, as a transportation fuel or in power generation. Estimating the magnitudes and likelihoods of achieving emissions reductions from competing end-uses of natural gas using LCA offers one way to examine optimal strategies of natural gas resource allocation, given that its availability is likely to be limited in the future. In this study, the uncertainty in life cycle GHG emissions of natural gas (domestic and imported) consumed in the U.S. was estimated using probabilistic modeling methods. Monte Carlo simulations are performed to obtain sample distributions representing life cycle GHG emissions from the use of 1 MJ of domestic natural gas and imported LNG. Life cycle GHG emissions per energy unit of average natural gas consumed in the U.S were found to range between -8 and 9% of the mean value of 66 g CO(2)e/MJ. The probabilities of achieving emissions reductions by using natural gas for transportation and power generation, as a substitute for incumbent fuels such as gasoline, diesel, and coal were estimated. The use of natural gas for power generation instead of coal was found to have the highest and most likely emissions reductions (almost a 100% probability of achieving reductions of 60 g CO(2)e/MJ of natural gas used), while there is a 10-35% probability of the emissions from natural gas being higher than the incumbent if it were used as a

  8. Comparative life-cycle air emissions of coal, domestic natural gas, LNG, and SNG for electricity generation.

    PubMed

    Jaramillo, Paulina; Griffin, W Michael; Matthews, H Scott

    2007-09-01

    The U.S. Department of Energy (DOE) estimates that in the coming decades the United States' natural gas (NG) demand for electricity generation will increase. Estimates also suggest that NG supply will increasingly come from imported liquefied natural gas (LNG). Additional supplies of NG could come domestically from the production of synthetic natural gas (SNG) via coal gasification-methanation. The objective of this study is to compare greenhouse gas (GHG), SOx, and NOx life-cycle emissions of electricity generated with NG/LNG/SNG and coal. This life-cycle comparison of air emissions from different fuels can help us better understand the advantages and disadvantages of using coal versus globally sourced NG for electricity generation. Our estimates suggest that with the current fleet of power plants, a mix of domestic NG, LNG, and SNG would have lower GHG emissions than coal. If advanced technologies with carbon capture and sequestration (CCS) are used, however, coal and a mix of domestic NG, LNG, and SNG would have very similar life-cycle GHG emissions. For SOx and NOx we find there are significant emissions in the upstream stages of the NG/ LNG life-cycles, which contribute to a larger range in SOx and NOx emissions for NG/LNG than for coal and SNG.

  9. Comparative life-cycle air emissions of coal, domestic natural gas, LNG, and SNG for electricity generation

    SciTech Connect

    Paulina Jaramillo; W. Michael Griffin; H. Scott Matthews

    2007-09-15

    The U.S. Department of Energy (DOE) estimates that in the coming decades the United States' natural gas (NG) demand for electricity generation will increase. Estimates also suggest that NG supply will increasingly come from imported liquefied natural gas (LNG). Additional supplies of NG could come domestically from the production of synthetic natural gas (SNG) via coal gasification-methanation. The objective of this study is to compare greenhouse gas (GHG), SOx, and NOx life-cycle emissions of electricity generated with NG/LNG/SNG and coal. This life-cycle comparison of air emissions from different fuels can help us better understand the advantages and disadvantages of using coal versus globally sourced NG for electricity generation. Our estimates suggest that with the current fleet of power plants, a mix of domestic NG, LNG, and SNG would have lower GHG emissions than coal. If advanced technologies with carbon capture and sequestration (CCS) are used, however, coal and a mix of domestic NG, LNG, and SNG would have very similar life-cycle GHG emissions. For SOx and NOx we find there are significant emissions in the upstream stages of the NG/LNG life-cycles, which contribute to a larger range in SOx and NOx emissions for NG/LNG than for coal and SNG. 38 refs., 3 figs., 2 tabs.

  10. 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…

  11. Emergence of life: from functional RNA selection to natural selection and beyond.

    PubMed

    Wong, Jeffrey Tze-Fei

    2014-06-01

    This study tracks the rise, evolution and post-evolution of the genetic information system through emergence of life. The major stages traversed include prebiotic synthesis, functional RNA selection by metabolite, RNA World, peptidated RNA world, co-evolution of genetic code and amino acid biosynthesis, last universal common ancestor, Darwinian evolution and synthetic life.

  12. 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.

  13. Molecular and life-history effects of a natural toxin on herbivorous and non-target soil arthropods.

    PubMed

    van Ommen Kloeke, A E Elaine; van Gestel, Cornelis A M; Styrishave, Bjarne; Hansen, Martin; Ellers, Jacintha; Roelofs, Dick

    2012-05-01

    Natural toxins, such as isothiocyanate (ITC), are harmful secondary metabolites produced by plants. Many natural toxins occur in commercial crops, yet their possible negative repercussions on especially non-target soil organisms are largely unknown. This study examined life-history and gene transcriptional responses to 2-phenylethyl ITC on two soil arthropod species: Folsomia candida and Protaphorura fimata. To that end the standardized ISO guideline for ecotoxicological tests and a microarray for F. candida were used. The dissipation of 2-phenylethyl ITC in natural soil was investigated using GC-MS/MS for quantification. Half-lives, tested at four concentration levels in natural soil, were on average 16 h with biodegradation as the plausible main removal process. Regardless, toxic effects on reproduction were shown for F. candida and P. fimata, with EC50 values of around 11.5 nmol/g soil illustrating the toxic character of this compound. Gene expression profiles revealed the importance of fatty acid metabolism at low exposure concentrations (EC10), which is associated with the lipophilic nature of 2-phenylethyl ITC. At higher concentrations (EC50) gene expression became more ubiquitous with over-expression of especially stress-related genes and sugar metabolism. The regulation of a gene encoding a precursor of follistatin, furthermore, implied the inhibition of reproduction and may be an important molecular target that can be linked to the observed adverse effect of life-history traits.

  14. 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.

  15. Contrasting developmental trajectories in the earliest known tetrapod forelimbs.

    PubMed

    Callier, Viviane; Clack, Jennifer A; Ahlberg, Per E

    2009-04-17

    Ichthyostega and Acanthostega are the earliest tetrapods known from multiple near-complete skeletons, with Acanthostega generally considered the more primitive. New material indicates differing ontogenetic trajectories for their forelimbs: In Ichthyostega, the pattern of muscle attachment processes on small humeri (upper arm bones) resembles that in "fish" members of the tetrapod stem group such as Tiktaalik, whereas large humeri approach (but fail to attain) the tetrapod crown-group condition; in Acanthostega, both small and large humeri exhibit the crown-group pattern. We infer that Ichthyostega underwent greater locomotory terrestrialization during ontogeny. The newly recognized primitive characteristics also suggest that Ichthyostega could be phylogenetically more basal than Acanthostega.

  16. Acoel flatworms: earliest extant bilaterian Metazoans, not members of Platyhelminthes.

    PubMed

    Ruiz-Trillo, I; Riutort, M; Littlewood, D T; Herniou, E A; Baguña, J

    1999-03-19

    Because of their simple organization the Acoela have been considered to be either primitive bilaterians or descendants of coelomates through secondary loss of derived features. Sequence data of 18S ribosomal DNA genes from non-fast evolving species of acoels and other metazoans reveal that this group does not belong to the Platyhelminthes but represents the extant members of the earliest divergent Bilateria, an interpretation that is supported by recent studies on the embryonic cleavage pattern and nervous system of acoels. This study has implications for understanding the evolution of major body plans, and for perceptions of the Cambrian evolutionary explosion.

  17. 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.

  18. Delta de l'Ebre is a natural bay model for Marteilia spp. (Paramyxea) dynamics and life-cycle studies.

    PubMed

    Carrasco, N; Arzul, I; Berthe, F C J; Fernández-Tejedor, M; Durfort, M; Furones, M D

    2008-03-03

    Marteilia spp. are paramyxean parasites that affect several bivalve species of economic interest, such as Ostrea edulis and Mytilus galloprovincialis. Certain aspects of Marteilia spp., such as their life cycle and host affinity and infection dynamics, still remain unknown. The 'Delta de l'Ebre' constitutes a natural model for the study of the life cycle of the parasite Marteilia, since uninfected mussels and flat oysters immersed in the bays can become infected. This, along with the geographical and ecological characteristics of the bays, make it a very interesting location to study the Marteilia life cycle. Preliminary results concerning marteiliosis, mainly in mussels, such as prevalence dynamics, infectious periods, host affinity and host intermediate candidates are reported in the present paper. This information will be required for further, more exhaustive, studies in the bays of the Ebre delta.

  19. Malaria life cycle intensifies both natural selection and random genetic drift.

    PubMed

    Chang, Hsiao-Han; Moss, Eli L; Park, Daniel J; Ndiaye, Daouda; Mboup, Souleymane; Volkman, Sarah K; Sabeti, Pardis C; Wirth, Dyann F; Neafsey, Daniel E; Hartl, Daniel L

    2013-12-10

    Analysis of genome sequences of 159 isolates of Plasmodium falciparum from Senegal yields an extraordinarily high proportion (26.85%) of protein-coding genes with the ratio of nonsynonymous to synonymous polymorphism greater than one. This proportion is much greater than observed in other organisms. Also unusual is that the site-frequency spectra of synonymous and nonsynonymous polymorphisms are virtually indistinguishable. We hypothesized that the complicated life cycle of malaria parasites might lead to qualitatively different population genetics from that predicted from the classical Wright-Fisher (WF) model, which assumes a single random-mating population with a finite and constant population size in an organism with nonoverlapping generations. This paper summarizes simulation studies of random genetic drift and selection in malaria parasites that take into account their unusual life history. Our results show that random genetic drift in the malaria life cycle is more pronounced than under the WF model. Paradoxically, the efficiency of purifying selection in the malaria life cycle is also greater than under WF, and the relative efficiency of positive selection varies according to conditions. Additionally, the site-frequency spectrum under neutrality is also more skewed toward low-frequency alleles than expected with WF. These results highlight the importance of considering the malaria life cycle when applying existing population genetic tools based on the WF model. The same caveat applies to other species with similarly complex life cycles.

  20. 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.

  1. 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

  2. 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…

  3. "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…

  4. Stress on health-related quality of life in older adults: the protective nature of mindfulness

    PubMed Central

    de Frias, Cindy M.; Whyne, Erum

    2015-01-01

    Objectives: The current study examined whether the link between stress and health-related quality of life was buffered by protective factors, namely mindfulness, in a sample of middle-aged and older adults. Methods: In this cross-sectional study, 134 healthy, community-dwelling adults (ages 50–85 years) were recruited from Dallas, TX. The participants were screened for depressive symptoms and severity (using the Patient Health Questionnaire [PHQ-9]). All participants completed measures of self-reported health status (i.e. SF36v2: mental and physical health composites), life stress (using the Elders Life Stress Inventory [ELSI]), and trait mindfulness (i.e. Mindful Attention Awareness Scale). Results: Hierarchical regressions (covarying for age, gender, and education) showed that life stress was inversely related to physical and mental health. Mindfulness was positively related to mental health. The negative effect of life stress on mental health was weakened for those individuals with higher levels of trait mindfulness. Conclusions: The results suggest that mindfulness is a powerful, adaptive strategy that may protect middle-aged and older adults from the well-known harmful effects of stress on mental health. PMID:24940847

  5. 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

  6. 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

    2016-01-12

    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.

  7. Cumulative exergy extraction from the natural environment (CEENE): a comprehensive life cycle impact assessment method for resource accounting.

    PubMed

    Dewulf, J; Bösch, M E; De Meester, B; Van der Vorst, G; Van Langenhove, H; Hellweg, S; Huijbregts, M A J

    2007-12-15

    The objective of the paper is to establish a comprehensive resource-based life cycle impact assessment (LCIA) method which is scientifically sound and that enables to assess all kinds of resources that are deprived from the natural ecosystem, all quantified on one single scale, free of weighting factors. The method is based on the exergy concept. Consistent exergy data on fossils, nuclear and metal ores, minerals, air, water, land occupation, and renewable energy sources were elaborated, with well defined system boundaries. Based on these data, the method quantifies the exergy "taken away" from natural ecosystems, and is thus called the cumulative exergy extraction from the natural environment (CEENE). The acquired data set was coupled with a state-of-the art life cycle inventory database, ecoinvent. In this way, the method is able to quantitatively distinguish eight categories of resources withdrawn from the natural environment: renewable resources, fossil fuels, nuclear energy, metal ores, minerals, water resources, land resources, and atmospheric resources. Third, the CEENE method is illustrated for a number of products that are available in ecoinvent, and results are compared with common resource oriented LCIA methods. The application to the materials in the ecoinvent database showed that fossil resources and land use are of particular importance with regard to the total CEENE score, although the other resource categories may also be significant.

  8. 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.

  9. 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

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

    PubMed

    Baumard, Nicolas; Chevallier, Coralie

    2015-11-07

    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.

  11. 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…

  12. 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

  13. 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.

  14. 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

    2015-07-07

    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.

  15. The earliest fossil evidence for sexual dimorphism in primates.

    PubMed

    Krishtalka, L; Stucky, R K; Beard, K C

    1990-07-01

    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.

  16. 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.

  17. Origin and radiation of the earliest vascular land plants.

    PubMed

    Steemans, Philippe; Hérissé, Alain Le; Melvin, John; Miller, Merrell A; Paris, Florentin; Verniers, Jacques; Wellman, Charles H

    2009-04-17

    Colonization of the land by plants most likely occurred in a stepwise fashion starting in the Mid-Ordovician. The earliest flora of bryophyte-like plants appears to have been cosmopolitan and dominated the planet, relatively unchanged, for some 30 million years. It is represented by fossilized dispersed cryptospores and fragmentary plant remains. In the Early Silurian, cryptospore abundance and diversity diminished abruptly as trilete spores appeared, became abundant, and underwent rapid diversification. This change coincides approximately with the appearance of vascular plant megafossils and probably represents the origin and adaptive radiation of vascular plants. We have obtained a diverse trilete spore occurrence from the Late Ordovician that suggests that vascular plants originated and diversified earlier than previously hypothesized, in Gondwana, before migrating elsewhere and secondarily diversifying.

  18. Paleontology. Shaking the earliest branches of anthropoid primate evolution.

    PubMed

    Jaeger, Jean-Jacques; Marivaux, Laurent

    2005-10-14

    Primates living today are believed to share a common ancestor that originated in either Africa or Asia. Fossil examples of such anthropoid ancestors have been found in both continents, so pushing back the origins to a single location has been controversial. In their Perspective, Jaeger and Marivaux discuss results reported in the same issue by Seiffert et al. that may put part of the controversy to rest. Seiffert et al. describe the earliest and most complete African anthropoid fossils from the Fayum desert region of Egypt. Cranial and dental fossils of two different small species were found, and their character, especially the features of the fossil teeth, suggests an ancient evolutionary history in Africa. At the same time, the phylogenetic analysis of Seiffert et al. is consistent with the view that African anthropoids immigrated from Asia at a very early date, probably before the late Paleocene (60 million years ago), possibly followed by later waves of immigration.

  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. 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.

  1. [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.

  2. 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

  3. 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.

  4. 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.

  5. Earliest evidence for commensal processes of cat domestication.

    PubMed

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

    2014-01-07

    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 δ(13)C and δ(15)N 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.

  6. 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.

  7. Life is Getting Better: Societal Evolution and Fit with Human Nature.

    PubMed

    Veenhoven, Ruut

    2010-05-01

    Human society has changed much over the last centuries and this process of 'modernization' has profoundly affected the lives of individuals; currently we live quite different lives from those forefathers lived only five generations ago. There is difference of opinion as to whether we live better now than before and consequently there is also disagreement as to whether we should continue modernizing or rather try to slow the process down. Quality-of-life in a society can be measured by how long and happy its inhabitants live. Using these indicators I assess whether societal modernization has made life better or worse. Firstly I examine findings of present day survey research. I start with a cross-sectional analysis of 143 nations in the years 2000-2008 and find that people live longer and happier in today's most modern societies. Secondly I examine trends in modern nations over the last decade and find that happiness and longevity have increased in most cases. Thirdly I consider the long-term and review findings from historical anthropology, which show that we lived better in the early hunter-gatherer society than in the later agrarian society. Together these data suggest that societal evolution has worked out differently for the quality of human life, first negatively, in the change from a hunter-gatherer existence to agriculture, and next positively, in the more recent transformation from an agrarian to an industrial society. We live now longer and happier than ever before.

  8. Estimation of shelf life of natural rubber latex exam-gloves based on creep behavior.

    PubMed

    Das, Srilekha Sarkar; Schroeder, Leroy W

    2008-05-01

    Samples of full-length glove-fingers cut from chlorinated and nonchlorinated latex medical examination gloves were aged for various times at several fixed temperatures and 25% relative humidity. Creep testing was performed using an applied stress of 50 kPa on rectangular specimens (10 mm x 8 mm) of aged and unaged glove fingers as an assessment of glove loosening during usage. Variations in creep curves obtained were compared to determine the threshold aging time when the amount of creep became larger than the initial value. These times were then used in various models to estimate shelf lives at lower temperatures. Several different methods of extrapolation were used for shelf-life estimation and comparison. Neither Q-factor nor Arrhenius activation energies, as calculated from 10 degrees C interval shift factors, were constant over the temperature range; in fact, both decreased at lower temperatures. Values of Q-factor and activation energies predicted up to 5 years of shelf life. Predictions are more sensitive to values of activation energy as the storage temperature departs from the experimental aging data. Averaging techniques for prediction of average activation energy predicted the longest shelf life as the curvature is reduced.

  9. Natural selection drives clinal life history patterns in the perennial sunflower species, Helianthus maximiliani.

    PubMed

    Kawakami, Takeshi; Morgan, Theodore J; Nippert, Jesse B; Ocheltree, Troy W; Keith, Rose; Dhakal, Preeti; Ungerer, Mark C

    2011-06-01

    In plants, ecologically important life history traits often display clinal patterns of population divergence. Such patterns can provide strong evidence for spatially varying selection across environmental gradients but also may result from nonselective processes, such as genetic drift, population bottlenecks and spatially restricted gene flow. Comparison of population differentiation in quantitative traits (measured as Q(ST) ) with neutral molecular markers (measured as F(ST) ) provides a useful tool for understanding the relative importance of adaptive and nonadaptive processes in the formation and maintenance of clinal variation. Here, we demonstrate the existence of geographic variation in key life history traits in the diploid perennial sunflower species Helianthus maximiliani across a broad latitudinal transect in North America. Strong population differentiation was found for days to flowering, growth rate and multiple size-related traits. Differentiation in these traits greatly exceeds neutral predictions, as determined both by partial Mantel tests and by comparisons of global Q(ST) values with theoretical F(ST) distributions. These findings indicate that clinal variation in these life history traits likely results from local adaptation driven by spatially heterogeneous environments.

  10. 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.

  11. 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.

  12. Prospects for energy efficiency improvement and reduction of emissions and life cycle costs for natural gas vehicles

    NASA Astrophysics Data System (ADS)

    Kozlov, A. V.; Terenchenko, A. S.; Luksho, V. A.; Karpukhin, K. E.

    2017-01-01

    This work is devoted to the experimental investigation of the possibilities to reduce greenhouse gas emissions and to increase energy efficiency of engines that use natural gas as the main fuel and the analysis of economic efficiency of use of dual fuel engines in vehicles compared to conventional diesel. The results of experimental investigation of a 190 kW dual-fuel engine are presented; it is shown that quantitative and qualitative working process control may ensure thermal efficiency at the same level as that of the diesel engine and in certain conditions 5...8% higher. The prospects for reduction of greenhouse gas emissions have been assessed. The technical and economic evaluation of use of dual fuel engines in heavy-duty vehicles has been performed, taking into account the total life cycle. It is shown that it is possible to reduce life cycle costs by two times.

  13. 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.

  14. The Contingent Constructed Nature of Social Life: Suggested Implications for Library and Information Science.

    ERIC Educational Resources Information Center

    Hall, Peter M.

    1990-01-01

    Discusses a variety of topics and their implications for library and information science professionals and their education. Highlights include the nature of science; contingency theories; the assumptions of sociology; the approach of symbolic interaction; recent scholarship on organizations; and the advantages of qualitative research methods.…

  15. 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.

  16. The hybrid nature of the Eukaryota and a consilient view of life on Earth.

    PubMed

    McInerney, James O; O'Connell, Mary J; Pisani, Davide

    2014-06-01

    The origin of the eukaryotic cell, which is known as eukaryogenesis, has puzzled scientists for more than 100 years, and many hypotheses have been proposed. Recent analyses of new data enable the safe elimination of some of these hypotheses, whereas support for other hypotheses has increased. In this Opinion article, we evaluate the available theories for their compatibility with empirical observations and conclude that cellular life consists of two primary, paraphyletic prokaryotic groups and one secondary, monophyletic group that has symbiogenic origins - the eukaryotes.

  17. Personality in its natural habitat: manifestations and implicit folk theories of personality in daily life.

    PubMed

    Mehl, Matthias R; Gosling, Samuel D; Pennebaker, James W

    2006-05-01

    To examine the expression of personality in its natural habitat, the authors tracked 96 participants over 2 days using the Electronically Activated Recorder (EAR), which samples snippets of ambient sounds in participants' immediate environments. Participants' Big Five scores were correlated with EAR-derived information on their daily social interactions, locations, activities, moods, and language use; these quotidian manifestations were generally consistent with the trait definitions and (except for Openness) often gender specific. To identify implicit folk theories about daily manifestations of personality, the authors correlated the EAR-derived information with impressions of participants based on their EAR sounds; judges' implicit folk theories were generally accurate (especially for Extraversion) and also partially gender specific. The findings point to the importance of naturalistic observation studies on how personality is expressed and perceived in the natural stream of everyday behavior.

  18. 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

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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)

  4. 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

  5. Lifetime selection on heritable life-history traits in a natural population of red squirrels.

    PubMed

    Réale, D; Berteaux, D; McAdam, A G; Boutin, S

    2003-10-01

    Despite their importance in evolutionary biology, heritability and the strength of natural selection have rarely been estimated in wild populations of iteroparous species or have usually been limited to one particular event during an organism's lifetime. Using an animal-model restricted maximum likelihood and phenotypic selection models, we estimated quantitative genetic parameters and the strength of lifetime selection on parturition date and litter size at birth in a natural population of North American red squirrels, Tamiasciurus hudsonicus. Litter size at birth and parturition date had low heritabilities (h2 = 0.15 and 0.16, respectively). We considered potential effects of temporal environmental covariances between phenotypes and fitness and of spatial environmental heterogeneity in estimates of selection. Selection favored early breeders and females that produced litter sizes close to the population average. Stabilizing selection on litter size at birth may occur because of a trade-off between number of offspring produced per litter and offspring survival or a trade-off between a female's fecundity and her future reproductive success and survival.

  6. 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.

  7. Bioorganic chemistry. A natural reunion of the physical and life sciences.

    PubMed

    Poulter, C Dale

    2009-04-03

    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 of my entree 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.

  8. 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.

  9. 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

  10. Fixational eye movements in the earliest stage of metazoan evolution.

    PubMed

    Bielecki, Jan; Høeg, Jens T; Garm, Anders

    2013-01-01

    All known photoreceptor cells adapt to constant light stimuli, fading the retinal image when exposed to an immobile visual scene. Counter strategies are therefore necessary to prevent blindness, and in mammals this is accomplished by fixational eye movements. Cubomedusae occupy a key position for understanding the evolution of complex visual systems and their eyes are assumedly subject to the same adaptive problems as the vertebrate eye, but lack motor control of their visual system. The morphology of the visual system of cubomedusae ensures a constant orientation of the eyes and a clear division of the visual field, but thereby also a constant retinal image when exposed to stationary visual scenes. Here we show that bell contractions used for swimming in the medusae refresh the retinal image in the upper lens eye of Tripedalia cystophora. This strongly suggests that strategies comparable to fixational eye movements have evolved at the earliest metazoan stage to compensate for the intrinsic property of the photoreceptors. Since the timing and amplitude of the rhopalial movements concur with the spatial and temporal resolution of the eye it circumvents the need for post processing in the central nervous system to remove image blur.

  11. The earliest Mesopsychidae and revision of the family Mesopanorpodidae (Mecoptera)

    PubMed Central

    Bashkuev, Alexei S.

    2011-01-01

    Abstract The family Mesopanorpodidae is revised. Most taxa referred to this family are not related to the type genus Mesopanorpodes Tillyard, 1918. The type species of the latter, Mesopanorpodes wianamattensis,is closely related to Mesopsyche Tillyard, 1917. Therefore Mesopanorpodes is transferred to Mesopsychidae Tillyard, 1917 (= Mesopanorpodidae Tillyard, 1918, syn. n.).The earliest Mesopsychidae are described from the Upper Permian of European Russia (Severodvinian; Isady locality, Vologda Province): Permopsyche issadensis gen. etsp. n. (type species) and Permopsyche rasnitsyni sp. n. Two species described under Mesopanorpodes from the Upper Permian of Australia are also included into Permopsyche: Permopsyche belmontensis (Riek, 1953), comb. n., Permopsyche robustus (Riek, 1953) comb. n. The first pre-Triassic Mesopsyche, Mesopsyche incompleta sp. n. is described from the uppermost Permian (the town of Vyazniki, Vladimir Province). Bittacopanorpa javorskii Zalessky, 1935 from the uppermost Permian or basal Triassic of Kuznetsk Basin is identified as a hindwing of Mesopsyche: Mesopsyche javorskii (Zalessky, 1935) comb. n. The origin, evolutionary history, and stratigraphic occurrence of Mesopsychidae are discussed. PMID:22259282

  12. 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.

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

    PubMed

    Andres, Brian; Clark, James; Xu, Xing

    2014-05-05

    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.

  14. The Formation and Growth of the Earliest Supermassive Black Holes

    NASA Astrophysics Data System (ADS)

    Aird, James; Comastri, Andrea; Topical Panel 2. 1

    2015-09-01

    Understanding how supermassive black holes (BHs) form and grow in the very early (z>6) Universe, when the first stars and galaxies were forming, is one of the major science aims of the Athena mission. The physical processes responsible for the initial formation of these BHs and their early growth via accretion - when they are seen as Active Galactic Nuclei (AGNs) - remain unclear. Large-scale optical/near-infrared imaging surveys have identified a few tens of luminous AGNs at z>6, powered by extremely massive BHs, and place vital constraints on the range of possible formation and growth mechanisms. To make further progress, however, we must identify lower luminosity and obscured AGNs at z>6, which represent the bulk of early BH growth. I will discuss recent measurements that trace the evolution of AGN population out to the highest possible redshifts (z~5-6) using the latest X-ray surveys with Chandra and XMM-Newton. However, Athena will provide the superb sensitivity over a wide field-of-view that is required to identify the earliest (z>6) growing BHs, trace their evolution within the early galaxy population, and determine the physical mechanisms that drive their formation and growth. Achieving these aims represents a major challenge that will push the capabilities of both Athena and supporting ground- and space-based observatories. I will present the prospects for a large Athena survey programme and discuss both the technical and scientific challenges that must be addressed in preparation for the Athena mission.

  15. Investigating the earliest stages of high-mass star formation

    NASA Astrophysics Data System (ADS)

    Fontani, Francesco; Dodson, Richard; Burton, Michael; Cesaroni, Riccardo; Brand, Jan; Molinari, Sergio; Sanchez-Monge, Alvaro; Rioja, Maria; Beltran, Maite

    2010-10-01

    We have recently performed a search for free-free continuum emission towards a sample of high-mass, star forming molecular clumps identified from single-dish observations of the 1.2 mm continuum and CS line emission. Our aim is to image a sub-sample of these clumps in the water maser line and four ammonia inversion transitions. The targets correspond to the earliest star formation phase: 25 IR-dark clumps plus a comparable number (15) of luminous, massive clumps undetected in our cm continuum survey with ATCA. Our goal is to verify the model by Molinari et al. (2008), which describes the evolution of a massive star from the prestellar phase to the main sequence. For this purpose we will use the ammonia lines to estimate the gas temperature and turbulence, and the water maser line to reveal embedded stars. Our expectation is that IR-dark sources will be colder, less turbulent, and less associated with H2O masers than IR-bright. The temperature estimates, combined with our previous 1.2 mm continuum measurements, will permit to obtain a better estimate of the clump masses and thus locate our sources more precisely on the evolutionary diagram of Molinari et al. (2008).

  16. 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.

  17. The fundamental nature of life as a chemical system: the part played by inorganic elements.

    PubMed

    Williams, Robert J P

    2002-02-01

    In this article we show why inorganic metal elements from the environment were an essential part of the origin of living aqueous systems of chemicals in flow. Unavoidably such systems have many closely fixed parameters, related to thermodynamic binding constants, for the interaction of the essential exchangeable inorganic metal elements with both inorganic and organic non-metal materials. The binding constants give rise to fixed free metal ion concentration profiles for different metal ions and ligands in the cytoplasm of all cells closely related to the Irving-Williams series. The amounts of bound elements depend on the organic molecules present as well as these free ion concentrations. This system must have predated coding which is probably only essential for reproductive life. Later evolution in changing chemical environments became based on the development of extra cytoplasmic compartments containing quite different energised free (and bound) element contents but in feed-back communication with the central primitive cytoplasm which changed little. Hence species multiplied late in evolution in large part due to the coupling with the altered inorganic environment.

  18. Impulsive for life? The nature of long-term impulsivity in domestic dogs.

    PubMed

    Riemer, Stefanie; Mills, Daniel S; Wright, Hannah

    2014-05-01

    Individual differences in impulsivity occur at a cognitive and/or behavioural level and are associated with differing life outcomes. However, there is a lack of empirical evidence to support the long-term stability of these characteristics in non-human animals. This study reports on the stability of convergent measures of impulsivity in domestic dogs assessed more than 6 years apart. Measures were (1) owner assessment by means of a questionnaire, the validated 'Dog Impulsivity Assessment Scale' (DIAS) and (2) dogs' performance in a delayed reward choice test. Dogs had 15-min free access to two food dispensers, one dispensing a piece of food immediately, the other dispensing three pieces after a delay, which increased by 1 s every other time the dogs sampled it. Maximum delay reached in this task reflects decision-making, or cognitive impulsivity, whereas the rate of extra presses on the delayed reward device during the delay can be considered as a measure of motor or behavioural impulsivity. DIAS scores were strongly and significantly correlated across years. The maximum delay reached in the behaviour test was also highly stable, whereas paw-pressing rate was uncorrelated between the years. These results demonstrate that cognitive but not motor impulsivity is highly consistent over time in dogs.

  19. 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

    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.

  20. 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

  1. The Dual Nature of Early-Life Experience on Somatosensory Processing in the Human Infant Brain.

    PubMed

    Maitre, Nathalie L; Key, Alexandra P; Chorna, Olena D; Slaughter, James C; Matusz, Pawel J; Wallace, Mark T; Murray, Micah M

    2017-04-03

    Every year, 15 million preterm infants are born, and most spend their first weeks in neonatal intensive care units (NICUs) [1]. Although essential for the support and survival of these infants, NICU sensory environments are dramatically different from those in which full-term infants mature and thus likely impact the development of functional brain organization [2]. Yet the integrity of sensory systems determines effective perception and behavior [3, 4]. In neonates, touch is a cornerstone of interpersonal interactions and sensory-cognitive development [5-7]. NICU treatments used to improve neurodevelopmental outcomes rely heavily on touch [8]. However, we understand little of how brain maturation at birth (i.e., prematurity) and quality of early-life experiences (e.g., supportive versus painful touch) interact to shape the development of the somatosensory system [9]. Here, we identified the spatial, temporal, and amplitude characteristics of cortical responses to light touch that differentiate them from sham stimuli in full-term infants. We then utilized this data-driven analytical framework to show that the degree of prematurity at birth determines the extent to which brain responses to light touch (but not sham) are attenuated at the time of discharge from the hospital. Building on these results, we showed that, when controlling for prematurity and analgesics, supportive experiences (e.g., breastfeeding, skin-to-skin care) are associated with stronger brain responses, whereas painful experiences (e.g., skin punctures, tube insertions) are associated with reduced brain responses to the same touch stimuli. Our results shed crucial insights into the mechanisms through which common early perinatal experiences may shape the somatosensory scaffolding of later perceptual, cognitive, and social development.

  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.

  3. Configurational approach to identifying the earliest hominin butchers.

    PubMed

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

    2010-12-07

    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.

  4. Configurational approach to identifying the earliest hominin butchers

    PubMed Central

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

    2010-01-01

    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. 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.

  7. 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

  8. Earliest Mexican Turkeys (Meleagris gallopavo) in the Maya Region: implications for pre-Hispanic animal trade and the timing of turkey domestication.

    PubMed

    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.

  9. 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

    2015-03-03

    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.

  10. 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

  11. The earliest known stem-tetrapod from the Lower Devonian of China.

    PubMed

    Lu, Jing; Zhu, Min; Long, John A; Zhao, Wenjin; Senden, Tim J; Jia, Liantao; Qiao, Tuo

    2012-01-01

    Recent discoveries of advanced fish-like stem-tetrapods (for example, Panderichthys and Tiktaalik) have greatly improved our knowledge of the fin-to-limb transition. However, a paucity of fossil data from primitive finned tetrapods prevents profound understanding of the acquisition sequence of tetrapod characters. Here we report a new stem-tetrapod (Tungsenia paradoxa gen. et sp. nov.) from the Lower Devonian (Pragian, ∼409 million years ago) of China, which extends the earliest record of tetrapods by some 10 million years. Sharing many primitive features with stem-lungfishes, the new taxon further fills in the morphological gap between tetrapods and lungfishes. The X-ray tomography study of the skull depicts the plesiomorphic condition of the brain in the tetrapods. The enlargement of the cerebral hemispheres and the possible presence of the pars tuberalis in this stem-tetrapod indicate that some important brain modifications related to terrestrial life had occurred at the beginning of the tetrapod evolution, much earlier than previously thought.

  12. Earliest memories in Israeli kibbutz upbringing: it is parental engagement that makes a difference.

    PubMed

    Aviezer, Ora; Sher-Censor, Efrat; Stein-Lahad, Tahel

    2017-03-30

    Culture and parenting shape the ability to recall early childhood experiences. This research focused on the unique context of upbringing in the Israeli kibbutz and examined how cultural orientation and experiences of parental engagement in Kibbutz and non-Kibbutz settings shaped adults' earliest memories. Participants were 108 women (study 1) and 75 women and men (study 2) who were raised in traditional kibbutz upbringing or in a non-kibbutz family setting. In addition to reporting their earliest memory and age at earliest memory, participants estimated retrospectively the amount of daily time spent in interaction with parents, caregivers, and other children during the time of earliest memory. Overall, upbringing-related variations in cultural orientation were evident in the content of memories. A prediction of later age at earliest memory due to limited opportunities for parent-child interaction characteristic of traditional kibbutz upbringing was not supported. Rather, in both studies, age at earliest memory was linked to retrospective estimation of parental engagement, after controlling for childhood ecology. Study 2 revealed also a link of age at earliest memory to retrospective estimation of involvement with non-parental caregivers. These findings are congruent with the social-interaction model's claims about the importance of interaction with caregiving adults to autobiographical memory's development.

  13. Ancients' Criterion of Earliest Visibility of the Lunar Crescent - how Good is it

    NASA Astrophysics Data System (ADS)

    Ilyas, M.

    Earliest visibility of the lunar crescent is an important calendrical element. It was needed in all early calendars and remains in use on some lunar calendars today. An astronomical criterion of earliest lunar visibility was therefore evolved quite early, using observations, right from the Babylonian era. Recently, an improved and comprehensive global criterion of earliest visibility, developed by the author, has been used to generate an extensive inverted moonset lag data set. These data, as a function of latitude and season, all for the first time provide a useful comparison with the simple ancient criterion.

  14. Mental health, life functioning and risk factors among people exposed to frequent natural disasters and chronic poverty in Vietnam

    PubMed Central

    Weiss, Bahr; Trung, Lam Tu

    2016-01-01

    Background People living in low- and middle-income countries (LMIC) are at increased risk for exposure to major natural disasters, which places them at increased risk for mental health problems. Evidence is less clear, however, regarding the effects of less severe but more frequent natural disasters, which are likely to increase due to global climate change. Aims To examine the mental health and life functioning, and their predictors, of people living in central coastal Vietnam – an area characterised by high risk for natural disasters and poverty. Method One thousand individuals were randomly selected from five provinces in central coastal Vietnam. Individuals were assessed cross-sectionally for exposure to major storms and other traumatic events (Post-traumatic Diagnostic Scale, or PDS), financial stress (Chronic Financial Stress Scale), depression (PHQ-9), anxiety (GAD-7), post-traumatic stress disorder (PTSD) (PDS), somatic syndrome (SCL-90-R), alcohol dependence (ICD-10), self-perceived general physical health (SF-36), and functional impairment (PDS life functioning section); caseness was determined using the various measures’ algorithms. Results 22.7% of the sample (n=227) met caseness criteria in one or more mental health domains, and 22.1% (n=221) reported moderate to severe functional impairment. Lifetime exposure to typhoons and other major storms was 99% (n=978), with 77% (n=742) reporting traumatic major storm exposure. Moderate to high levels of financial stress were reported by 30% (n=297). Frequency of exposure to major storms was not associated with increased risk for mental health problems but traumatic exposure to a major storm was. Overall, the strongest predictor of mental health problems was financial stress. Number of traumatic typhoons and other major storms in turn were significant predictors (r2=0.03) of financial stress. The primary predictor of alcohol dependence was male gender, highlighting the importance of gender roles in

  15. Life cycle emissions and cost of producing electricity from coal, natural gas, and wood pellets in Ontario, Canada.

    PubMed

    Zhang, Yimin; McKechnie, Jon; Cormier, Denis; Lyng, Robert; Mabee, Warren; Ogino, Akifumi; Maclean, Heather L

    2010-01-01

    The use of coal is responsible for (1)/(5) of global greenhouse gas (GHG) emissions. Substitution of coal with biomass fuels is one of a limited set of near-term options to significantly reduce these emissions. We investigate, on a life cycle basis, 100% wood pellet firing and cofiring with coal in two coal generating stations (GS) in Ontario, Canada. GHG and criteria air pollutant emissions are compared with current coal and hypothetical natural gas combined cycle (NGCC) facilities. 100% pellet utilization provides the greatest GHG benefit on a kilowatt-hour basis, reducing emissions by 91% and 78% relative to coal and NGCC systems, respectively. Compared to coal, using 100% pellets reduces NO(x) emissions by 40-47% and SO(x) emissions by 76-81%. At $160/metric ton of pellets and $7/GJ natural gas, either cofiring or NGCC provides the most cost-effective GHG mitigation ($70 and $47/metric ton of CO2 equivalent, respectively). The differences in coal price, electricity generation cost, and emissions at the two GS are responsible for the different options being preferred. A sensitivity analysis on fuel costs reveals considerable overlap in results for all options. A lower pellet price ($100/metric ton) results in a mitigation cost of $34/metric ton of CO2 equivalent for 10% cofiring at one of the GS. The study results suggest that biomass utilization in coal GS should be considered for its potential to cost-effectively mitigate GHGs from coal-based electricity in the near term.

  16. Trauma and autobiographical memory: contents and determinants of earliest memories among war-affected Palestinian children.

    PubMed

    Peltonen, Kirsi; Kangaslampi, Samuli; Qouta, Samir; Punamäki, Raija-Leena

    2017-03-23

    The contents of earliest memories (EM), as part of autobiographical memory, continue to fascinate scientists and therapists. However, research is scarce on the determinants of EM, especially among children. This study aims, first, to identify contents of EM of children living in war conditions, and, second, to analyse child gender, traumatic events and mental health as determinants of the contents of EM. The participants were 240 Palestinian schoolchildren from the Gaza Strip (10-12 years, M = 11.35, SD = 0.57; 49.4% girls). They responded to an open-ended EM question, and reported their trauma exposures (war trauma, losses and current traumatic events), posttraumatic stress, depressive symptoms and psychosocial well-being, indicating mental health. The EM coding involved nature, social orientation, emotional tone and specificity. Results showed, first, that 43% reported playing or visiting a nice place as EM, and about a third (30%) traumatic events or accidents (30%) or miscellaneous events (27%). The individual and social orientation were almost equally common, the emotional tone mainly neutral (45.5%), and 60% remembered a specific event. Second, boys remembered more EM involving traumatic events or accidents, and girls more social events. Third, war trauma was associated with less positive emotional tone and with more specific memories.

  17. The hexagram "Feng" in "the book of changes" as the earliest written record of sunspot

    NASA Astrophysics Data System (ADS)

    Xu, Zhen-tao

    1980-12-01

    The hexagram "Feng" of the "Book of Changes" (completed before 800 B.C.) contains the statements "a dou is seen in the Sun" and "a mei is seen in the Sun". The character dou (bushel) is generally understood to refer to an obscured region in this context. As to the character mei, a passage in the "Biography of Wang Mang" in "The History of the Later Han Dynasty" written in 450 A.D. shoes that it is synonymous with the character xing (star), and according to "Kaiyuan Treatise on Prognostication" written in 729 A.D., both dou and xing in this context refer to an obscuration. Lastly, in the years 1626, 1643 and 1684, years of relatively high solar activities over the period 1610-1700 (Eddy, Science192 (1976) 1189), when sunspots were seen in telescopes in Europe (cf. Bray and Loughhead, "Sunspots" 1964, Plate 1.1), these two very same statements are found in some Local Gazettes of China (Xu Zhen-tao and Jiang Yao-tiao, Annals of Nanjing University, (Natural Sciences Series), No. 2, 1979). Thus, the earliest written record of a sunspot is found in China, in this book which was completed before 800 B.C.

  18. 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

  19. 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

  20. 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

  1. Glycine identification in natural jarosites using laser desorption Fourier transform mass spectrometry: implications for the search for life on Mars.

    PubMed

    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, Na(2)SO(4) and K(2)SO(4). 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.

  2. Acquisition of natural humoral immunity to P. falciparum in early life in Benin: impact of clinical, environmental and host factors

    PubMed Central

    Dechavanne, Célia; Sadissou, Ibrahim; Bouraima, Aziz; Ahouangninou, Claude; Amoussa, Roukiyath; Milet, Jacqueline; Moutairou, Kabirou; Massougbodji, Achille; Theisen, Michael; Remarque, Edmond J.; Courtin, David; Nuel, Gregory; Migot-Nabias, Florence; Garcia, André

    2016-01-01

    To our knowledge, effects of age, placental malaria infection, infections during follow-up, nutritional habits, sickle-cell trait and individual exposure to Anopheles bites were never explored together in a study focusing on the acquisition of malaria antibody responses among infants living in endemic areas.Five hundred and sixty-seven Beninese infants were weekly followed-up from birth to 18 months of age. Immunoglobulin G (IgG), IgG1 and IgG3 specific for 5 malaria antigens were measured every 3 months. A linear mixed model was used to analyze the effect of each variable on the acquisition of antimalarial antibodies in 6-to18-month old infants in univariate and multivariate analyses. Placental malaria, nutrition intakes and sickle-cell trait did not influence the infant antibody levels to P. falciparum antigens. In contrary, age, malaria antibody levels at birth, previous and present malaria infections as well as exposure to Anopheles bites were significantly associated with the natural acquisition of malaria antibodies in 6-to18-month old Beninese infants. This study highlighted inescapable factors to consider simultaneously in an immuno-epidemiological study or a vaccine trial in early life. PMID:27670685

  3. Integrating early life experience, gene expression, brain development, and emergent phenotypes: unraveling the thread of nature via nurture.

    PubMed

    Weaver, Ian C G

    2014-01-01

    Adaptation to environmental changes is based on the perpetual generation of new phenotypes. Modern biology has focused on the role of epigenetic mechanisms in facilitating the adaptation of organisms to changing environments through alterations in gene expression. Inherited and/or acquired epigenetic factors are relatively stable and have regulatory roles in numerous genomic activities that translate into phenotypic outcomes. Evidence that dietary and pharmacological interventions have the potential to reverse environment-induced modification of epigenetic states (e.g., early life experience, nutrition, medication, infection) has provided an additional stimulus for understanding the biological basis of individual differences in cognitive abilities and disorders of the brain. It has been suggested that accurate quantification of the relative contribution of heritable genetic and epigenetic variation is essential for understanding phenotypic divergence and adaptation in changing environments, a process requiring stable modulation of gene expression. The main challenge for epigenetics in psychology and psychiatry is to determine how experiences and environmental cues, including the nature of our nurture, influence the expression of neuronal genes to produce long-term individual differences in behavior, cognition, personality, and mental health. To this end, focusing on DNA and histone modifications and their initiators, mediators and readers may provide new inroads for understanding the molecular basis of phenotypic plasticity and disorders of the brain. In this chapter, we review recent discoveries highlighting epigenetic aspects of normal brain development and mental illness, as well as discuss some future directions in the field of behavioral epigenetics.

  4. Spatial summation revealed in the earliest visual evoked component C1 and the effect of attention on its linearity.

    PubMed

    Chen, Juan; Yu, Qing; Zhu, Ziyun; Peng, Yujia; Fang, Fang

    2016-01-01

    In natural scenes, multiple objects are usually presented simultaneously. How do specific areas of the brain respond to multiple objects based on their responses to each individual object? Previous functional magnetic resonance imaging (fMRI) studies have shown that the activity induced by a multiobject stimulus in the primary visual cortex (V1) can be predicted by the linear or nonlinear sum of the activities induced by its component objects. However, there has been little evidence from electroencephelogram (EEG) studies so far. Here we explored how V1 responded to multiple objects by comparing the EEG signals evoked by a three-grating stimulus with those evoked by its two components (the central grating and 2 flanking gratings). We focused on the earliest visual component C1 (onset latency of ∼50 ms) because it has been shown to reflect the feedforward responses of neurons in V1. We found that when the stimulus was unattended, the amplitude of the C1 evoked by the three-grating stimulus roughly equaled the sum of the amplitudes of the C1s evoked by its two components, regardless of the distances between these gratings. When the stimulus was attended, this linear spatial summation existed only when the three gratings were far apart from each other. When the three gratings were close to each other, the spatial summation became compressed. These results suggest that the earliest visual responses in V1 follow a linear summation rule when attention is not involved and that attention can affect the earliest interactions between multiple objects.

  5. The False Spring of 2012, Earliest in North American Record

    NASA Astrophysics Data System (ADS)

    Ault, T. R.; Henebry, G. M.; de Beurs, K. M.; Schwartz, M. D.; Betancourt, J. L.; Moore, D.

    2013-05-01

    Phenology—the study of recurring plant and animal life cycle stages, especially their timing and relationships with weather and climate—is becoming an essential tool for documenting, communicating, and anticipating the consequences of climate variability and change. For example, March 2012 broke numerous records for warm temperatures and early flowering in the United States [Karl et al., 2012; Elwood et al., 2013]. Many regions experienced a "false spring," a period of weather in late winter or early spring sufficiently mild and long to bring vegetation out of dormancy prematurely, rendering it vulnerable to late frost and drought.

  6. The Divergent Thinking of Basic Skills of Sciences Process Skills of Life Aspects on Natural Sciences Subject in Indonesian Elementary School Students

    ERIC Educational Resources Information Center

    Subali, Bambang; Paidi; Mariyam, Siti

    2016-01-01

    This research aims at measuring the divergent thinking of basic skills of science process skills (SPS) of life aspects in Natural Sciences subjects on Elementary School. The test instruments used in this research have been standardized through the development of instruments. In this case, the tests were tried out to 3070 students. The results of…

  7. 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

  8. The false spring of 2012, earliest in North American record

    USGS Publications Warehouse

    Ault, T.R.; Henebry, G.M.; de Beurs, K. M.; Schwartz, M.D.; Betancourt, Julio L.; Moore, David

    2013-01-01

    Phenology - the study of recurring plant and animal life cycle stages, especially their timing and relationships with weather and climate - is becoming an essential tool for documenting, communicating, and anticipating the consequences of climate variability and change. For example, March 2012 broke numerous records for warm temperatures and early flowering in the United States [Karl et al., 2012; Elwood et al., 2013]. Many regions experienced a “false spring,” a period of weather in late winter or early spring sufficiently mild and long to bring vegetation out of dormancy prematurely, rendering it vulnerable to late frost and drought.As global climate warms, increasingly warmer springs may combine with the random climatological occurrence of advective freezes, which result from cold air moving from one region to another, to dramatically increase the future risk of false springs, with profound ecological and economic consequences [e.g., Gu et al., 2008; Marino et al., 2011; Augspurger, 2013]. For example, in the false spring of 2012, an event embedded in long-term trends toward earlier spring [e.g., Schwartz et al., 2006], the frost damage to fruit trees totaled half a billion dollars in Michigan alone, prompting the federal government to declare the state a disaster area [Knudson, 2012].

  9. 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.

  10. 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

  11. Age at earliest reported memory: associations with personality traits, behavioral health, and repression.

    PubMed

    Spirrison, C L; McCarley, N G

    2001-09-01

    The present study examined relationships between the age at earliest memory and the personality traits and behavioral health of 107 undergraduates. Participants answered questions on their earliest memory and completed the Myers-Briggs Type Indicator (MBTI) and a medical history form. Analyses indicated that continuous scores on two MBTI scales (Sensing-Intuition and Judging-Perceiving) were inversely related to age at earliest memory as were participant's self-reported drug and alcohol problems, emotional and psychological symptoms, accident rates, physical symptoms, and satisfaction with health. Respondents who reported first memories at or after 7 years of age (i.e., approximately 1 SD above the mean age at recalled memory) were classified as repressors. Repressors scored in the Sensing and Judging directions on the MBTI and reported significantly fewer emotional symptoms, accidents, psychological symptoms, and less health satisfaction than nonrepressors. Results are consistent with the age at earliest memory and repression literature and support the use of earliest memory age as an index of repression.

  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. 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.

  14. 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.

  15. 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.

  16. 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

  17. Birth to Three Matters: A Framework to Support Children in Their Earliest Years

    ERIC Educational Resources Information Center

    Abbott, Lesley; Langston, Ann

    2005-01-01

    Government commitment to the care and education of children from birth to three years in England led to the commissioning in 2001 of "a framework of best practice" (DfEE, 2001:24) to support children in their earliest years. The resulting framework of "effective" practice, together with supporting materials, was developed by a…

  18. 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…

  19. 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…

  20. Early silurian spore tetrads from new york: earliest new world evidence for vascular plants?

    PubMed

    Gray, J; Boucot, A J

    1971-09-03

    Several taxa of abundant cutinized trilete spores from earliest Silurian shale in New York predate by almost an entire period vascular land plant megafossils. Paleoecological evidence suggests that these spores may represent vascular land or semiaquatic plants but a bryophytic origin cannot be precluded on the basis of spore characters. An algal origin is considered unlikely.

  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. Using the Significant Life Experience Framework to Inform Program Evaluation: The Nature Conservancy's Wings & Water Wetlands Education Program

    ERIC Educational Resources Information Center

    Cachelin, Adrienne; Paisley, Karen; Blanchard, Angela

    2009-01-01

    Significant life experience research suggests that outdoor experiences foster proenvironmental outcomes. Time spent outdoors is more frequently identified as the source of proenvironmental behavior than is education, suggesting that cognition may be less important than affect. Yet, environmental education field programs are often evaluated on…

  3. Using a Total Environment Framework (Built, Natural, Social Environments) to Assess Life-long Health Effects of Chemical Exposures

    EPA Pesticide Factsheets

    EPAseeks applications for research on how pollution affects human health in the context of the total environment – built, natural, and social environments interacting together with inherent characteristics and interactions.

  4. Lactic acid bacteria and natural antimicrobials to improve the safety and shelf-life of minimally processed sliced apples and lamb's lettuce.

    PubMed

    Siroli, Lorenzo; Patrignani, Francesca; Serrazanetti, Diana I; Tabanelli, Giulia; Montanari, Chiara; Gardini, Fausto; Lanciotti, Rosalba

    2015-05-01

    Outbreaks of food-borne disease associated with the consumption of fresh and minimally processed fruits and vegetables have increased dramatically over the last few years. Traditional chemical sanitizers are unable to completely eradicate or kill the microorganisms on fresh produce. These conditions have stimulated research to alternative methods for increasing food safety. The use of protective cultures, particularly lactic acid bacteria (LAB), has been proposed for minimally processed products. However, the application of bioprotective cultures has been limited at the industrial level. From this perspective, the main aims of this study were to select LAB from minimally processed fruits and vegetables to be used as biocontrol agents and then to evaluate the effects of the selected strains, alone or in combination with natural antimicrobials (2-(E)-hexenal/hexanal, 2-(E)-hexenal/citral for apples and thyme for lamb's lettuce), on the shelf-life and safety characteristics of minimally processed apples and lamb's lettuce. The results indicated that applying the Lactobacillus plantarum strains CIT3 and V7B3 to apples and lettuce, respectively, increased both the safety and shelf-life. Moreover, combining the selected strains with natural antimicrobials produced a further increase in the shelf-life of these products without detrimental effects on the organoleptic qualities.

  5. 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.

  6. Characterizing molecular clouds in the earliest phases of high-mass star formation

    NASA Astrophysics Data System (ADS)

    Sanhueza, Patricio A.

    High-mass stars play a key role in the energetics and chemical evolution. of molecular clouds and galaxies. However, the mechanisms that allow. the formation of high-mass stars are far less clear than those of. their low-mass. counterparts. Most of the research on high-mass star formation has focused. on regions currently undergoing star formation. In contrast, objects. in the earlier prestellar stage have been more difficult to identify. Recently, it has been. suggested that the cold, massive, and dense Infrared Dark Clouds (IRDCs) host. the earliest stages of high-mass star formation. The chemistry of IRDCs remains poorly explored. In this dissertation, an. observational program to search for chemical. variations in IRDC clumps as a function of their age is described. An increase in N2H+ and HCO+ abundances. is found from the quiescent, cold phase to the protostellar, warmer phases, reflecting chemical. evolution. For HCO+ abundances, the observed trend is consistent with. theoretical predictions. However, chemical models fail to explain the observed. trend of increasing N2H+ abundances. Pristine high-mass prestellar clumps are ideal for testing and constraining. theories of high-mass star formation because their predictions differ. the most at the early stages of evolution. From the initial IRDC sample, a high-mass clump that is the best candidate to be in the prestellar phase. was selected (IRDC G028.23-00.19 MM1). With a new set of observations, the prestellar nature of the clump is confirmed. High-angular resolution. observations of IRDC G028.23-00.19 suggest that in. order to form high-mass stars, the detected cores have to accrete a large. amount of material, passing through a low- to intermediate-mass phase. before having the necessary mass to form a. high-mass star. The turbulent core accretion model. is inconsistent with this observational result, but on the other hand, the. observations support the competitive accretion model. Embedded cores have. to

  7. Comparative analysis of the production costs and life-cycle GHG emissions of FT liquid fuels from coal and natural gas.

    PubMed

    Jaramillo, Paulina; Griffin, W Michael; Matthews, H Scott

    2008-10-15

    Liquid transportation fuels derived from coal and natural gas could helpthe United States reduce its dependence on petroleum. The fuels could be produced domestically or imported from fossil fuel-rich countries. The goal of this paper is to determine the life-cycle GHG emissions of coal- and natural gas-based Fischer-Tropsch (FT) liquids, as well as to compare production costs. The results show that the use of coal- or natural gas-based FT liquids will likely lead to significant increases in greenhouse gas (GHG) emissions compared to petroleum-based fuels. In a best-case scenario, coal- or natural gas-based FT-liquids have emissions only comparable to petroleum-based fuels. In addition, the economic advantages of gas-to-liquid (GTL) fuels are not obvious: there is a narrow range of petroleum and natural gas prices at which GTL fuels would be competitive with petroleum-based fuels. CTLfuels are generally cheaper than petroleum-based fuels. However, recent reports suggest there is uncertainty about the availability of economically viable coal resources in the United States. If the U.S. has a goal of increasing its energy security, and at the same time significantly reducing its GHG emissions, neither CTL nor GTL consumption seem a reasonable path to follow.

  8. Extraordinary fossils reveal the nature of Cambrian life: a commentary on Whittington (1975) 'The enigmatic animal Opabinia regalis, Middle Cambrian, Burgess Shale, British Columbia'.

    PubMed

    Briggs, Derek E G

    2015-04-19

    Harry Whittington's 1975 monograph on Opabinia was the first to highlight how some of the Burgess Shale animals differ markedly from those that populate today's oceans. Categorized by Stephen J. Gould as a 'weird wonder' (Wonderful life, 1989) Opabinia, together with other unusual Burgess Shale fossils, stimulated ongoing debates about the early evolution of the major animal groups and the nature of the Cambrian explosion. The subsequent discovery of a number of other exceptionally preserved fossil faunas of Cambrian and early Ordovician age has significantly augmented the information available on this critical interval in the history of life. Although Opabinia initially defied assignment to any group of modern animals, it is now interpreted as lying below anomalocaridids on the stem leading to the living arthropods. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society.

  9. Extraordinary fossils reveal the nature of Cambrian life: a commentary on Whittington (1975) ‘The enigmatic animal Opabinia regalis, Middle Cambrian, Burgess Shale, British Columbia’

    PubMed Central

    Briggs, Derek E. G.

    2015-01-01

    Harry Whittington's 1975 monograph on Opabinia was the first to highlight how some of the Burgess Shale animals differ markedly from those that populate today's oceans. Categorized by Stephen J. Gould as a ‘weird wonder’ (Wonderful life, 1989) Opabinia, together with other unusual Burgess Shale fossils, stimulated ongoing debates about the early evolution of the major animal groups and the nature of the Cambrian explosion. The subsequent discovery of a number of other exceptionally preserved fossil faunas of Cambrian and early Ordovician age has significantly augmented the information available on this critical interval in the history of life. Although Opabinia initially defied assignment to any group of modern animals, it is now interpreted as lying below anomalocaridids on the stem leading to the living arthropods. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society. PMID:25750235

  10. 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.

  11. The Wilderness Expedition: An Effective Life Course Intervention to Improve Young People's Well-Being and Connectedness to Nature

    ERIC Educational Resources Information Center

    Barton, Jo; Bragg, Rachel; Pretty, Jules; Roberts, Jo; Wood, Carly

    2016-01-01

    It is well understood that wilderness expeditions improve well-being; however, there is little supporting quantitative data. The aim of this study was to measure the impact of wilderness expeditions on self-esteem (SE) and connectedness to nature (CN) and assess whether benefits varied according to participant and expedition characteristics. SE…

  12. Choosing natural enemies for conservation biological control: use of the prey detectability half-life to rank agroecosystem predators

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agroecosystems are speciose, making selection of natural enemies for conservation biological control non-trivial. Molecular gut analysis enables ranking of predators by the incidence of pest remains in the gut. However, predators differ in digestive rates, and ranking by incidence favors those with ...

  13. 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.

  14. The study of capability natural uranium as fuel cycle input for long life gas cooled fast reactors with helium as coolant

    NASA Astrophysics Data System (ADS)

    Ariani, Menik; Satya, Octavianus Cakra; Monado, Fiber; Su'ud, Zaki; Sekimoto, Hiroshi

    2016-03-01

    The objective of the present research is to assess the feasibility design of small long-life Gas Cooled Fast Reactor with helium as coolant. GCFR included in the Generation-IV reactor systems are being developed to provide sustainable energy resources that meet future energy demand in a reliable, safe, and proliferation-resistant manner. This reactor can be operated without enrichment and reprocessing forever, once it starts. To obtain the capability of consuming natural uranium as fuel cycle input modified CANDLE burn-up scheme was adopted in this system with different core design. This study has compared the core with three designs of core reactors with the same thermal power 600 MWth. The fuel composition each design was arranged by divided core into several parts of equal volume axially i.e. 6, 8 and 10 parts related to material burn-up history. 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 region 1 is filled by fresh natural uranium fuel. This concept is basically applied to all regions, i.e. shifted the core of the region (i) into region (i+1) region after the end of 10 years burn-up cycle. The calculation results shows that for the burn-up strategy on "Region-8" and "Region-10" core designs, after the reactors start-up the operation furthermore they only needs natural uranium supply to the next life operation until one period of refueling (10 years).

  15. 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.

  16. The earliest giant Osprioneides borings from the Sandbian (late ordovician) of Estonia.

    PubMed

    Vinn, Olev; Wilson, Mark A; Mõtus, Mari-Ann

    2014-01-01

    The earliest Osprioneides kampto borings were found in bryozoan colonies of Sandbian age from northern Estonia (Baltica). The Ordovician was a time of great increase in the quantities of hard substrate removed by single trace makers. Increased predation pressure was most likely the driving force behind the infaunalization of larger invertebrates such as the Osprioneides trace makers in the Ordovician. It is possible that the Osprioneides borer originated in Baltica or in other paleocontinents outside of North America.

  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. Earliest mechanical evidence of cross-bridge activity after stimulation of single skeletal muscle fibers.

    PubMed

    Claflin, D R; Morgan, D L; Julian, F J

    1990-03-01

    The stiffness of single fibers from frog skeletal muscle was measured by the application of small 2-kHz sinusoidal length oscillations during twitch and tetanic contractions at a range of initial sarcomere lengths. The earliest mechanical signs of activation were a fall in tension (latency relaxation) and a rise in stiffness. The earliest stiffness increase and the earliest tension fall occurred simultaneously at all sarcomere lengths. This suggests a cross-bridge origin for the latency relaxation. The lead of stiffness over tension seen during the rise of tension was substantially established during the latent period. Reducing the size of the twitch by reducing calcium release with D-600 (methoxyverapamil) reduced the latency relaxation and the stiffness development during latency much less than it reduced the twitch tension. For very small twitches the peak of the stiffness response occurred during the latent period and the times of onset of both latency relaxation and stiffness rise were delayed, but remained coincident. This suggests a strong connection between the latency relaxation and the rise of stiffness during the latent period, whereas the connection between these events and positive tension generation appears to be less strong.

  19. Virtual endocranial cast of earliest Eocene Diacodexis (Artiodactyla, Mammalia) and morphological diversity of early artiodactyl brains.

    PubMed

    Orliac, M J; Gilissen, E

    2012-09-22

    The study of brain evolution, particularly that of the neocortex, is of primary interest because it directly relates to how behavioural variations arose both between and within mammalian groups. Artiodactyla is one of the most diverse mammalian clades. However, the first 10 Myr of their brain evolution has remained undocumented so far. Here, we used high-resolution X-ray computed tomography to investigate the endocranial cast of Diacodexis ilicis of earliest Eocene age. Its virtual reconstruction provides unprecedented access to both metric parameters and fine anatomy of the most complete endocast of the earliest artiodactyl. This picture is assessed in a broad comparative context by reconstructing endocasts of 14 other Early and Middle Eocene representatives of basal artiodactyls, allowing the tracking of the neocortical structure of artiodactyls back to its simplest pattern. We show that the earliest artiodactyls share a simple neocortical pattern, so far never observed in other ungulates, with an almond-shaped gyrus instead of parallel sulci as previously hypothesized. Our results demonstrate that artiodactyls experienced a tardy pulse of encephalization during the Late Neogene, well after the onset of cortical complexity increase. Comparisons with Eocene perissodactyls show that the latter reached a high level of cortical complexity earlier than the artiodactyls.

  20. Overall results of and lessons learned from the IAEA CRP on sodium natural circulation test performed during the Phenix end-of-life experiments

    SciTech Connect

    Monti, S.; Toti, A.; Tenchine, D.; Pialla, D.

    2012-07-01

    In 2007, the International Atomic Energy Agency (IAEA) launched the Coordinated Research Project (CRP) 'Control Rod Withdrawal and Sodium Natural Circulation Tests Performed during the Phenix End-of-Life Experiments'. The overall purpose of the CRP, performed within the framework of the IAEA programme in support of innovative fast reactor technology development and deployment, is to improve the Member States' analytical capabilities in the various fields of research and design of sodium-cooled fast reactors through data and codes verification and validation. In particular the CRP, taking advantage of the End-of-Life set of experiments performed before the final shut-down of the French prototype fast breeder power reactor Phenix, aims at improving fast reactor simulation methods and design capabilities in the field of temperature and power distribution evaluation, as well as of the analysis of sodium natural circulation phenomena. The paper presents the overall results of the CRP, including blind calculations and post-test and sensitivity analyses carried out by the CRP participants, as well as lessons learned and recommendations for further future implementations to resolve open issues. (authors)

  1. Antioxidant capacity of "Mexican arnica" Heterotheca inuloides Cass natural products and some derivatives: their anti-inflammatory evaluation and effect on C. elegans life span.

    PubMed

    Rodríguez-Chávez, José Luis; Coballase-Urrutia, Elvia; Nieto-Camacho, Antonio; Delgado-Lamas, Guillermo

    2015-01-01

    It has been suggested that the accumulation of biomolecular damage caused by reactive oxygen species (ROS) contributes to aging. The antioxidant activity is related to the ability of certain compounds to protect against the potentially harmful effect of processes or reactions involving ROS. This ability is associated with the termination of free radical propagation in biological systems. From Heterotheca inuloides various compounds which have shown to possess antioxidant capacity and scavenging ROS. The aim of this study was to determine the antioxidant capacity of additional natural components isolated from H. inuloides and some semisynthetic derivatives, their anti-inflammatory activity and the effect on Caenorhabditis elegans nematode life span. Compounds showed ability to inhibit various biological processes such as lipid peroxidation, scavenge nonbiological important oxidants such as (1)O2, OH(∙), H2O2, and HOCl and scavenge non biological stable free radicals (DPPH). Some cadinane type compounds showed possess antioxidant, ROS scavenging capacity, anti-inflammatory activity, and effect on the C. elegans life span. Flavonoid type compounds increased the life of the nematode and quercetin was identified as the compound with the greatest activity. The modification of chemical structure led to a change in the antioxidant capacity, the anti-inflammatory activity, and the survival of the worm.

  2. Antioxidant Capacity of “Mexican Arnica” Heterotheca inuloides Cass Natural Products and Some Derivatives: Their Anti-Inflammatory Evaluation and Effect on C. elegans Life Span

    PubMed Central

    Rodríguez-Chávez, José Luis; Nieto-Camacho, Antonio; Delgado-Lamas, Guillermo

    2015-01-01

    It has been suggested that the accumulation of biomolecular damage caused by reactive oxygen species (ROS) contributes to aging. The antioxidant activity is related to the ability of certain compounds to protect against the potentially harmful effect of processes or reactions involving ROS. This ability is associated with the termination of free radical propagation in biological systems. From Heterotheca inuloides various compounds which have shown to possess antioxidant capacity and scavenging ROS. The aim of this study was to determine the antioxidant capacity of additional natural components isolated from H. inuloides and some semisynthetic derivatives, their anti-inflammatory activity and the effect on Caenorhabditis elegans nematode life span. Compounds showed ability to inhibit various biological processes such as lipid peroxidation, scavenge nonbiological important oxidants such as 1O2, OH∙, H2O2, and HOCl and scavenge non biological stable free radicals (DPPH). Some cadinane type compounds showed possess antioxidant, ROS scavenging capacity, anti-inflammatory activity, and effect on the C. elegans life span. Flavonoid type compounds increased the life of the nematode and quercetin was identified as the compound with the greatest activity. The modification of chemical structure led to a change in the antioxidant capacity, the anti-inflammatory activity, and the survival of the worm. PMID:25821555

  3. Effectiveness of two-sided UV-C treatments in inhibiting natural microflora and extending the shelf-life of minimally processed 'Red Oak Leaf' lettuce.

    PubMed

    Allende, Ana; McEvoy, James L; Luo, Yaguang; Artes, Francisco; Wang, Chien Y

    2006-05-01

    The use of UV-C radiation treatments to inhibit the microbial growth and extend the shelf-life of minimally processed 'Red Oak Leaf' lettuce was investigated. Initially, UV-C resistance of 20 bacterial strains from different genera often associated with fresh produce (Enterobacter, Erwinia, Escherichia, Leuconostoc, Pantoea, Pseudomonas, Rahnela, Salmonella, Serratia and Yersinia) were tested in vitro. Most of the bacterial strains were inhibited with the minimum dose (30 J m(-2)). Erwinia carotovora, Leuconostoc carnosum, Salmonella typhimurium, and Yersinia aldovae were the most resistant strains requiring a UV-C dose of 85 J m(-2) to completely inhibit growth. An in vivo study consisted of treating minimally processed 'Red Oak Leaf' lettuce (Lactuca sativa) with UV-C at three radiation doses (1.18, 2.37 and 7.11 kJ m(-2)) on each side of the leaves and storing the product under passive MAP conditions at 5 degrees C for up to 10 days. The gas composition inside packages varied significantly among the treatments, with CO2 concentrations positively and O2 concentrations negatively correlating with the radiation dose. All the radiation doses were effective in reducing the natural microflora of the product, although the highest doses showed the greatest microbial inhibitions. Taking into account the microbial limit set by Spanish legislation [Boletín Oficial del Estado (BOE), 2001. Normas de higiene para la elaboración, distribución y comercio de comidas preparadas, Madrid, Spain, Real Decreto 3484/2000, pp. 1435-1441], all UV-C treatments extended the shelf-life of the product. However, the 7.11 kJ m(-2) dose induced tissue softening and browning after 7 days of storage at 5 degrees C. Therefore, the use of two sided UV-C radiation, at the proper dose, is effective in reducing the natural microflora and extending the shelf-life of minimally processed 'Red Oak Leaf' lettuce.

  4. Effect of Addition of Natural Antioxidants on the Shelf-Life of "Chorizo", a Spanish Dry-Cured Sausage.

    PubMed

    Pateiro, Mirian; Bermúdez, Roberto; Lorenzo, José Manuel; Franco, Daniel

    2015-01-14

    The dose effect of the addition of natural antioxidants (tea, chestnut, grape seed and beer extracts) on physicochemical, microbiological changes and on oxidative stability of dry-cured "chorizo", as well as their effect during the storage under vacuum conditions was evaluated. Color parameters were significantly (p < 0.05) affected by the addition of antioxidants so that samples that contained antioxidants were more effective in maintaining color. The improving effects were dose-dependent with highest values with the dose of 50 mg/kg during ripening and depend on the extract during vacuum packaging. Addition of antioxidants decreased (p < 0.05) the oxidation, showing thiobarbituric acid reactive substances (TBARS) values below 0.4 mg MDA/kg. Natural antioxidants matched or even improved the results obtained for butylated hydroxytoluene (BHT). Regarding texture profile analysis (TPA) analysis, hardness values significantly (p < 0.001) decreased with the addition of antioxidants, obtaining the lower results with the dose of 200 mg/kg both during ripening and vacuum packaging. Antioxidants reduced the counts of total viable counts (TVC), lactic acid bacteria (LAB), mold and yeast. Free fatty acid content during ripening and under vacuum conditions showed a gradual and significant (p < 0.05) release as a result of lipolysis. At the end of ripening, the addition of GRA1000 protected chorizos from oxidative degradation.

  5. Posttranslational modification and sequence variation of redox-active proteins correlate with biofilm life cycle in natural microbial communities

    SciTech Connect

    Singer, Steven; Erickson, Brian K; Verberkmoes, Nathan C; Hwang, Mona; Shah, Manesh B; Hettich, Robert {Bob} L; Banfield, Jillian F.; Thelen, Michael P.

    2010-01-01

    Characterizing proteins recovered from natural microbial communities affords the opportunity to correlate protein expression and modification with environmental factors, including species composition and successional stage. Proteogenomic and biochemical studies of pellicle biofilms from subsurface acid mine drainage streams have shown abundant cytochromes from the dominant organism, Leptospirillum Group II. These cytochromes are proposed to be key proteins in aerobic Fe(II) oxidation, the dominant mode of cellular energy generation by the biofilms. In this study, we determined that posttranslational modification and expression of amino-acid sequence variants change as a function of biofilm maturation. For Cytochrome579 (Cyt579), the most abundant cytochrome in the biofilms, late developmental-stage biofilms differed from early-stage biofilms in N-terminal truncations and decreased redox potentials. Expression of sequence variants of two monoheme c-type cytochromes also depended on biofilm development. For Cyt572, an abundant membrane-bound cytochrome, the expression of multiple sequence variants was observed in both early and late developmental-stage biofilms; however, redox potentials of Cyt572 from these different sources did not vary significantly. These cytochrome analyses show a complex response of the Leptospirillum Group II electron transport chain to growth within a microbial community and illustrate the power of multiple proteomics techniques to define biochemistry in natural systems.

  6. Intrafamilial similarities and cross-generational differences in the earliest childhood memories of daughters, mothers, and grandmothers.

    PubMed

    Sahin-Acar, Basak; Bakir, Tugce; Kus, Elif Gizem

    2016-10-17

    This study aimed to examine how daughters, mothers, and grandmothers from the same families resembled each other and how these three generations differed from each other in narrating their earliest childhood memories. Fifty-nine triads from the same families filled out a memory questionnaire and were asked to narrate their earliest childhood memories. Results revealed both intrafamilial similarities and cross-generational difference on characteristics of triads' earliest childhood memories. After earliest childhood memories were coded for memory characteristics, we measured intrafamilial similarities using intra-class correlation coefficients across three generations for each memory characteristic. Results revealed that the earliest childhood memories of members of the same family were significantly similar in terms of level of detail and volume. Although similar patterns among members of the same families were observed in self-related and other-related words, the other/self ratio did not display an intrafamilial similarity. We also measured cross-generational differences and found that daughters' reported age of their earliest childhood memories was dated significantly earlier compared to their grandmothers. Results revealed predominant intrafamilial similarities among the members of the same family and cross-generational differences in terms of the age of the earliest childhood memory.

  7. Nature and Age of Neighbours Matter: Interspecific Associations among Tree Species Exist and Vary across Life Stages in Tropical Forests

    PubMed Central

    Ledo, Alicia

    2015-01-01

    Detailed information about interspecific spatial associations among tropical tree species is scarce, and hence the ecological importance of those associations may have been underestimated. However, they can play a role in community assembly and species diversity maintenance. This study investigated the spatial dependence between pairs of species. First, the spatial associations (spatial attraction and spatial repulsion) that arose between species were examined. Second, different sizes of trees were considered in order to evaluate whether the spatial relationships between species are constant or vary during the lifetime of individuals. Third, the consistency of those spatial associations with the species-habitat associations found in previous studies was assessed. Two different tropical ecosystems were investigated: a montane cloud forest and a lowland moist forest. The results showed that spatial associations among species exist, and these vary among life stages and species. The rarity of negative spatial interactions suggested that exclusive competition was not common in the studied forests. On the other hand, positive interactions were common, and the results of this study strongly suggested that habitat associations were not the only cause of spatial attraction among species. If this is true, habitat associations and density dependence are not the only mechanisms that explain species distribution and diversity; other ecological interactions, such as facilitation among species, may also play a role. These spatial associations could be important in the assembly of tropical tree communities and forest succession, and should be taken into account in future studies. PMID:26581110

  8. Natural growth and diet of known-age pallid sturgeon (Scaphirhynchus albus) early life stages in the upper Missouri River basin, Montana and North Dakota

    USGS Publications Warehouse

    Braaten, P.J.; Fuller, D.B.; Lott, R.D.; Haddix, T.M.; Holte, L.D.; Wilson, R.H.; Bartron, M.L.; Kalie, J.A.; DeHaan, P.W.; Ardren, W.R.; Holm, R.J.; Jaeger, M.E.

    2012-01-01

    Prior to anthropogenic modifications, the historic Missouri River provided ecological conditions suitable for reproduction, growth, and survival of pallid sturgeon Scaphirhynchus albus. However, little information is available to discern whether altered conditions in the contemporary Missouri River are suitable for feeding, growth and survival of endangered pallid sturgeon during the early life stages. In 2004 and 2007, nearly 600 000 pallid sturgeon free embryos and larvae were released in the upper Missouri River and survivors from these releases were collected during 2004–2010 to quantify natural growth rates and diet composition. Based on genetic analysis and known-age at release (1–17 days post-hatch, dph), age at capture (dph, years) could be determined for each survivor. Totals of 23 and 28 survivors from the 2004 and 2007 releases, respectively, were sampled. Growth of pallid sturgeon was rapid (1.91 mm day-1) during the initial 13–48 dph, then slowed as fish approached maximum length (120–140 mm) towards the end of the first growing season. The diet of young-of-year pallid sturgeon was comprised of Diptera larvae, Diptera pupae, and Ephemeroptera nymphs. Growth of pallid sturgeon from ages 1–6 years was about 48.0 mm year-1. This study provides the first assessment of natural growth and diet of young pallid sturgeon in the wild. Results depict pallid sturgeon growth trajectories that may be expected for naturally produced wild stocks under contemporary habitat conditions in the Missouri River and Yellowstone River.

  9. Can environmental conditions experienced in early life influence future generations?

    PubMed Central

    Burton, Tim; Metcalfe, Neil B.

    2014-01-01

    The consequences of early developmental conditions for performance in later life are now subjected to convergent interest from many different biological sub-disciplines. However, striking data, largely from the biomedical literature, show that environmental effects experienced even before conception can be transmissible to subsequent generations. Here, we review the growing evidence from natural systems for these cross-generational effects of early life conditions, showing that they can be generated by diverse environmental stressors, affect offspring in many ways and can be transmitted directly or indirectly by both parental lines for several generations. In doing so, we emphasize why early life might be so sensitive to the transmission of environmentally induced effects across generations. We also summarize recent theoretical advancements within the field of developmental plasticity, and discuss how parents might assemble different ‘internal’ and ‘external’ cues, even from the earliest stages of life, to instruct their investment decisions in offspring. In doing so, we provide a preliminary framework within the context of adaptive plasticity for understanding inter-generational phenomena that arise from early life conditions. PMID:24807254

  10. Stress-induced hypermutation as a physical property of life, a force of natural selection and its role in four thought experiments

    NASA Astrophysics Data System (ADS)

    Hilbert, Lennart

    2013-04-01

    The independence of genetic mutation rate from selection is central to neo-Darwinian evolutionary theory. However, it has been continuously challenged for more than 30 years by experimental evidence of genetic mutation rate transiently increasing in response to stress (stress-induced hypermutation, SIH). The prominent concept of evolved evolvability (EE) explains that natural selection for strategies more competitive at evolutionary adaptation itself gives rise to mechanisms dynamically adjusting mutation rates to environmental stress. Here, we theoretically investigate the alternative (not mutually exclusive) hypothesis that SIH is an inherent physical property of all genetically reproducing life. We define stress as any condition lowering the capability of utilizing metabolic resources for genome storage and replication. This thermodynamical analysis indicates stress-induced increases in the genetic mutation rate in genome storage and in genome replication as inherent physical properties of genetically reproducing life. Further integrating SIH into an overall organismic thermodynamic budget identifies SIH as a force of natural selection, alongside death rate, replication rate and constitutive mutation rate differences. We execute four thought experiments with a non-recombinant lesion mutant strain to predict experimental observations due to SIH in response to different stresses and stress combinations. We find (1) acceleration of adaptation over models without SIH, (2) possibility of adaptation at high stresses which are not explicable by mutation in genome replication alone and (3) different adaptive potential under high growth-inhibiting versus high lethal stresses. The predictions are directly comparable to culture experiments (colony size time courses, antibacterial resistance assay and occurrence of lesion-reversion mutant colonies) and genome sequence analysis. Considering suggestions of drug-mediated disruption of SIH and attempts to target mutation

  11. 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

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

    NASA Astrophysics Data System (ADS)

    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.

  13. 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

  14. 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

    2016-01-07

    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.

  15. Matematica Natural.

    ERIC Educational Resources Information Center

    Lozano, Patricia; Medearis, Linda

    Matematica Natural (Natural Mathematics) is a mathematics curriculum for young children based on the assumption that they learn mathematics through concrete, real life, relevant experiences and that educational differences rather than cultural differences influence math achievement. The curriculum uses hands-on materials and activities to teach…

  16. Nature Detectives

    ERIC Educational Resources Information Center

    Harr, Natalie; Lee, Richard E.; Jr.

    2010-01-01

    Richard Louv's "Last Child in the Woods" (2008) added to a growing consensus to get children outside and experiencing nature. Using ideas from place-based education, the authors present a simple year-long project that brings science, nature, and other curriculum standards to life right in your school yard. With a focus on journaling, this project…

  17. Structural mouthpart interaction evolved already in the earliest lineages of insects.

    PubMed

    Blanke, Alexander; Rühr, Peter T; Mokso, Rajmund; Villanueva, Pablo; Wilde, Fabian; Stampanoni, Marco; Uesugi, Kentaro; Machida, Ryuichiro; Misof, Bernhard

    2015-08-07

    In butterflies, bees, flies and true bugs specific mouthparts are in close contact or even fused to enable piercing, sucking or sponging of particular food sources. The common phenomenon behind these mouthpart types is a complex composed of several consecutive mouthparts which structurally interact during food uptake. The single mouthparts are thus only functional in conjunction with other adjacent mouthparts, which is fundamentally different to biting-chewing. It is, however, unclear when structural mouthpart interaction (SMI) evolved since this principle obviously occurred multiple times independently in several extant and extinct winged insect groups. Here, we report a new type of SMI in two of the earliest wingless hexapod lineages--Diplura and Collembola. We found that the mandible and maxilla interact with each other via an articulatory stud at the dorsal side of the maxillary stipes, and they are furthermore supported by structures of the hypopharynx and head capsule. These interactions are crucial stabilizing elements during food uptake. The presence of SMI in these ancestrally wingless insects, and its absence in those crustacean groups probably ancestral to insects, indicates that SMI is a groundplan apomorphy of insects. Our results thus contradict the currently established view of insect mouthpart evolution that biting-chewing mouthparts without any form of SMI are the ancestral configuration. Furthermore, SMIs occur in the earliest insects in a high anatomical variety. SMIs in stemgroup representatives of insects may have triggered efficient exploitation and fast adaptation to new terrestrial food sources much earlier than previously supposed.

  18. Structural mouthpart interaction evolved already in the earliest lineages of insects

    PubMed Central

    Blanke, Alexander; Rühr, Peter T.; Mokso, Rajmund; Villanueva, Pablo; Wilde, Fabian; Stampanoni, Marco; Uesugi, Kentaro; Machida, Ryuichiro; Misof, Bernhard

    2015-01-01

    In butterflies, bees, flies and true bugs specific mouthparts are in close contact or even fused to enable piercing, sucking or sponging of particular food sources. The common phenomenon behind these mouthpart types is a complex composed of several consecutive mouthparts which structurally interact during food uptake. The single mouthparts are thus only functional in conjunction with other adjacent mouthparts, which is fundamentally different to biting–chewing. It is, however, unclear when structural mouthpart interaction (SMI) evolved since this principle obviously occurred multiple times independently in several extant and extinct winged insect groups. Here, we report a new type of SMI in two of the earliest wingless hexapod lineages—Diplura and Collembola. We found that the mandible and maxilla interact with each other via an articulatory stud at the dorsal side of the maxillary stipes, and they are furthermore supported by structures of the hypopharynx and head capsule. These interactions are crucial stabilizing elements during food uptake. The presence of SMI in these ancestrally wingless insects, and its absence in those crustacean groups probably ancestral to insects, indicates that SMI is a groundplan apomorphy of insects. Our results thus contradict the currently established view of insect mouthpart evolution that biting–chewing mouthparts without any form of SMI are the ancestral configuration. Furthermore, SMIs occur in the earliest insects in a high anatomical variety. SMIs in stemgroup representatives of insects may have triggered efficient exploitation and fast adaptation to new terrestrial food sources much earlier than previously supposed. PMID:26203002

  19. Notes on historical aspects on the earliest known observations of noctilucent clouds

    NASA Astrophysics Data System (ADS)

    Dalin, P.; Pertsev, N.; Romejko, V.

    2012-03-01

    The present paper considers historical aspects of the earliest known observations of noctilucent clouds (NLCs). The 1884 and 1885 are discussed by considering important historical citations by the pioneers of the earliest known observations of noctilucent clouds. For the first time in NLC studies, we consider seven major volcanic eruptions: Laki in 1783, Mount St. Helens in 1800, Tambora in 1815, Galunggung in 1822, Cosigüina in 1835, Shiveluch in 1854 and Askja in 1875. These all preceded the catastrophic 1883 eruption of Krakatoa, which despite having a lesser magnitude than Tambora in 1815, had pronounced effects on the atmosphere. These eruptions represent possible triggers for the appearance of NLCs. For the first time, we publish an unknown, in English-speaking literature, historical fact on the first determinations of the altitude of noctilucent clouds made by two Russian astronomers V. K. Tseraskii and A. A. Belopolskii on 26 June 1885, who managed to infer the altitude of the clouds in the range of 73-83 km, that is, for the first time, demonstrating the possible existence of the clouds at great altitudes in the Earth's atmosphere. Moreover, V. K. Tseraskii was the first observer to photograph noctilucent clouds in 1885 or 1886, which is 1-2 yr before the German astronomer O. Jesse, who owns the first published images of noctilucent clouds. The photographs made by V. K. Tseraskii, unfortunately, did not reach us.

  20. The emergence of core eudicots: new floral evidence from the earliest Late Cretaceous

    PubMed Central

    Pedersen, Kaj Raunsgaard; Crane, Peter R.

    2016-01-01

    Eudicots, the most diverse of the three major clades of living angiosperms, are first recognized in the latest Barremian–earliest Aptian. All Early Cretaceous forms appear to be related to species-poor lineages that diverged before the rise of core eudicots, which today comprise more than 70% of angiosperm species. Here, we report the discovery of a well-preserved flower, Caliciflora mauldinensis, from the earliest Late Cretaceous, with unequivocal core eudicot features, including five sepals, five petals and two whorls of stamens borne on the rim of a floral cup containing three free carpels. Pollen is tricolporate. Carpels mature into follicular fruitlets. This character combination suggests a phylogenetic position among rosids, but more specific assignment is precluded by complex patterns of character evolution among the very large number of potentially relevant extant taxa. The whorled floral organization is consistent with ideas that this stable pattern evolved early and was a prerequisite for more integrated patterns of floral architecture that evolved later. However, limited floral synorganization in Caliciflora and all earlier eudicot flowers recognized so far, calls into question hypotheses that substantial diversification of core eudicots had already occurred by the end of the Early Cretaceous. PMID:28003443

  1. The earliest modern mongoose (Carnivora, Herpestidae) from Africa (late Miocene of Chad).

    PubMed

    Peigné, Stéphane; de Bonis, Louis; Likius, Andossa; Mackaye, Hassane Taïsso; Vignaud, Patrick; Brunet, Michel

    2005-06-01

    We report on the earliest modern mongooses of Africa, from the late Miocene (ca. 7 Ma) of the hominid locality TM 266, Toros-Menalla, Chad. The material is based on fragmentary dentitions of three individuals. The main diagnostic feature of the Chadian species is the great development of the shear in the carnassials, which distinguishes the Chadian specimens from all extant herpestids except Herpestes and Galerella. In comparison with most extinct and extant Herpestes, the species from Toros-Menalla differs by a markedly smaller size and, depending on the species, relatively more elongated carnassials, more transversely elongated M1 and more reduced p4. On the basis of a great morphological similarity and the absence of significant differences, we assign our material to Galerella sanguinea; the Chadian finding therefore represents the earliest appearance of an extant species of Herpestidae. This record ties the first appearance of the genus to a minimum age of ca. 7 Ma, which is consistent with the estimated divergence date of 11.4 Ma known from the literature for the species of Galerella.

  2. The earliest modern mongoose (Carnivora, Herpestidae) from Africa (late Miocene of Chad)

    NASA Astrophysics Data System (ADS)

    Peigné, Stéphane; Bonis, Louis; Likius, Andossa; Mackaye, Hassane Taïsso; Vignaud, Patrick; Brunet, Michel

    2005-06-01

    We report on the earliest modern mongooses of Africa, from the late Miocene (ca. 7 Ma) of the hominid locality TM 266, Toros-Menalla, Chad. The material is based on fragmentary dentitions of three individuals. The main diagnostic feature of the Chadian species is the great development of the shear in the carnassials, which distinguishes the Chadian specimens from all extant herpestids except Herpestes and Galerella. In comparison with most extinct and extant Herpestes, the species from Toros-Menalla differs by a markedly smaller size and, depending on the species, relatively more elongated carnassials, more transversely elongated M1 and more reduced p4. On the basis of a great morphological similarity and the absence of significant differences, we assign our material to Galerella sanguinea; the Chadian finding therefore represents the earliest appearance of an extant species of Herpestidae. This record ties the first appearance of the genus to a minimum age of ca. 7 Ma, which is consistent with the estimated divergence date of 11.4 Ma known from the literature for the species of Galerella.

  3. Earliest events in α-synuclein fibrillation probed with the fluorescence of intrinsic tyrosines.

    PubMed

    Saraiva, Marco A; Jorge, Carla D; Santos, Helena; Maçanita, António L

    2016-01-01

    The fluorescence of the four tyrosines of α-synuclein (Syn) was used for probing the earliest events preceding the fibrillation of Syn, during the onset of the so-called lag-time of fibrillation. Steady-state fluorescence experiments revealed an increase in the fluorescence intensity (FI) for Syn solutions at pH values 3 and 2, in comparison with pH7, and fluorescence decays indicated that the FI increase did not result from suppression of excited-state proton transfer from the tyrosines to aspartates and glutamates, exposure of tyrosines to more hydrophobic environments, or reduction of homo-energy transfer. Instead, the FI increase was due to changes in the population of the tyrosine rotamers at low pH values. Stopped-flow experiments (pH-jumps) showed that the FI enhancement involves two processes: a fast (sub-7 ms) intramolecular (concentration-independent) process, which we assign to the protein collapse at low pH, and a slower intermolecular (concentration-dependent) process of protein dimerization/oligomerization, starting at 4-10s after acidification. To the best of our knowledge, this is the first work on the experimental detection of these earliest processes in the fibrillation of Syn.

  4. Ice-core evidence of earliest extensive copper metallurgy in the Andes 2700 years ago

    NASA Astrophysics Data System (ADS)

    Eichler, A.; Gramlich, G.; Kellerhals, T.; Tobler, L.; Rehren, Th.; Schwikowski, M.

    2017-01-01

    The importance of metallurgy for social and economic development is indisputable. Although copper (Cu) was essential for the wealth of pre- and post-colonial societies in the Andes, the onset of extensive Cu metallurgy in South America is still debated. Comprehensive archaeological findings point to first sophisticated Cu metallurgy during the Moche culture ~200–800 AD, whereas peat-bog records from southern South America suggest earliest pollution potentially from Cu smelting as far back as ~2000 BC. Here we present a 6500-years Cu emission history for the Andean Altiplano, based on ice-core records from Illimani glacier in Bolivia, providing the first complete history of large-scale Cu smelting activities in South America. We find earliest anthropogenic Cu pollution during the Early Horizon period ~700–50 BC, and attribute the onset of intensified Cu smelting in South America to the activities of the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time substantial evidence for extensive Cu metallurgy already during these early cultures.

  5. Ice-core evidence of earliest extensive copper metallurgy in the Andes 2700 years ago.

    PubMed

    Eichler, A; Gramlich, G; Kellerhals, T; Tobler, L; Rehren, Th; Schwikowski, M

    2017-01-31

    The importance of metallurgy for social and economic development is indisputable. Although copper (Cu) was essential for the wealth of pre- and post-colonial societies in the Andes, the onset of extensive Cu metallurgy in South America is still debated. Comprehensive archaeological findings point to first sophisticated Cu metallurgy during the Moche culture ~200-800 AD, whereas peat-bog records from southern South America suggest earliest pollution potentially from Cu smelting as far back as ~2000 BC. Here we present a 6500-years Cu emission history for the Andean Altiplano, based on ice-core records from Illimani glacier in Bolivia, providing the first complete history of large-scale Cu smelting activities in South America. We find earliest anthropogenic Cu pollution during the Early Horizon period ~700-50 BC, and attribute the onset of intensified Cu smelting in South America to the activities of the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time substantial evidence for extensive Cu metallurgy already during these early cultures.

  6. Earliest economic exploitation of chicken outside East Asia: Evidence from the Hellenistic Southern Levant.

    PubMed

    Perry-Gal, Lee; Erlich, Adi; Gilboa, Ayelet; Bar-Oz, Guy

    2015-08-11

    Chicken (Gallus gallus domesticus) is today one of the most widespread domesticated species and is a main source of protein in the human diet. However, for thousands of years exploitation of chickens was confined to symbolic and social domains such as cockfighting. The question of when and where chickens were first used for economic purposes remains unresolved. The results of our faunal analysis demonstrate that the Hellenistic (fourth-second centuries B.C.E.) site of Maresha, Israel, is the earliest site known today where economic exploitation of chickens was widely practiced. We base our claim on the exceptionally high frequency of chicken bones at that site, the majority of which belong to adult individuals, and on the observed 2:1 ratio of female to male bones. These results are supported further by an extensive survey of faunal remains from 234 sites in the Southern Levant, spanning more than three millennia, which shows a sharp increase in the frequency of chicken during the Hellenistic period. We further argue that the earliest secure evidence for economic exploitation of chickens in Europe dates to the first century B.C.E. and therefore is predated by the finds in the Southern Levant by at least a century. We suggest that the gradual acclimatization of chickens in the Southern Levant and its gradual integration into the local economy, the latter fully accomplished in the Hellenistic period, was a crucial step in the adoption of this species in European husbandry some 100 y later.

  7. The emergence of core eudicots: new floral evidence from the earliest Late Cretaceous.

    PubMed

    Friis, Else Marie; Pedersen, Kaj Raunsgaard; Crane, Peter R

    2016-12-28

    Eudicots, the most diverse of the three major clades of living angiosperms, are first recognized in the latest Barremian-earliest Aptian. All Early Cretaceous forms appear to be related to species-poor lineages that diverged before the rise of core eudicots, which today comprise more than 70% of angiosperm species. Here, we report the discovery of a well-preserved flower, Caliciflora mauldinensis, from the earliest Late Cretaceous, with unequivocal core eudicot features, including five sepals, five petals and two whorls of stamens borne on the rim of a floral cup containing three free carpels. Pollen is tricolporate. Carpels mature into follicular fruitlets. This character combination suggests a phylogenetic position among rosids, but more specific assignment is precluded by complex patterns of character evolution among the very large number of potentially relevant extant taxa. The whorled floral organization is consistent with ideas that this stable pattern evolved early and was a prerequisite for more integrated patterns of floral architecture that evolved later. However, limited floral synorganization in Caliciflora and all earlier eudicot flowers recognized so far, calls into question hypotheses that substantial diversification of core eudicots had already occurred by the end of the Early Cretaceous.

  8. Ice-core evidence of earliest extensive copper metallurgy in the Andes 2700 years ago

    PubMed Central

    Eichler, A.; Gramlich, G.; Kellerhals, T.; Tobler, L.; Rehren, Th.; Schwikowski, M.

    2017-01-01

    The importance of metallurgy for social and economic development is indisputable. Although copper (Cu) was essential for the wealth of pre- and post-colonial societies in the Andes, the onset of extensive Cu metallurgy in South America is still debated. Comprehensive archaeological findings point to first sophisticated Cu metallurgy during the Moche culture ~200–800 AD, whereas peat-bog records from southern South America suggest earliest pollution potentially from Cu smelting as far back as ~2000 BC. Here we present a 6500-years Cu emission history for the Andean Altiplano, based on ice-core records from Illimani glacier in Bolivia, providing the first complete history of large-scale Cu smelting activities in South America. We find earliest anthropogenic Cu pollution during the Early Horizon period ~700–50 BC, and attribute the onset of intensified Cu smelting in South America to the activities of the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time substantial evidence for extensive Cu metallurgy already during these early cultures. PMID:28139760

  9. Laetoli Footprints Preserve Earliest Direct Evidence of Human-Like Bipedal Biomechanics

    PubMed Central

    Raichlen, David A.; Gordon, Adam D.; Harcourt-Smith, William E. H.; Foster, Adam D.; Haas, Wm. Randall

    2010-01-01

    Background Debates over the evolution of hominin bipedalism, a defining human characteristic, revolve around whether early bipeds walked more like humans, with energetically efficient extended hind limbs, or more like apes with flexed hind limbs. The 3.6 million year old hominin footprints at Laetoli, Tanzania represent the earliest direct evidence of hominin bipedalism. Determining the kinematics of Laetoli hominins will allow us to understand whether selection acted to decrease energy costs of bipedalism by 3.6 Ma. Methodology/Principal Findings Using an experimental design, we show that the Laetoli hominins walked with weight transfer most similar to the economical extended limb bipedalism of humans. Humans walked through a sand trackway using both extended limb bipedalism, and more flexed limb bipedalism. Footprint morphology from extended limb trials matches weight distribution patterns found in the Laetoli footprints. Conclusions These results provide us with the earliest direct evidence of kinematically human-like bipedalism currently known, and show that extended limb bipedalism evolved long before the appearance of the genus Homo. Since extended-limb bipedalism is more energetically economical than ape-like bipedalism, energy expenditure was likely an important selection pressure on hominin bipeds by 3.6 Ma. PMID:20339543

  10. Earliest economic exploitation of chicken outside East Asia: Evidence from the Hellenistic Southern Levant

    PubMed Central

    Perry-Gal, Lee; Erlich, Adi; Gilboa, Ayelet; Bar-Oz, Guy

    2015-01-01

    Chicken (Gallus gallus domesticus) is today one of the most widespread domesticated species and is a main source of protein in the human diet. However, for thousands of years exploitation of chickens was confined to symbolic and social domains such as cockfighting. The question of when and where chickens were first used for economic purposes remains unresolved. The results of our faunal analysis demonstrate that the Hellenistic (fourth–second centuries B.C.E.) site of Maresha, Israel, is the earliest site known today where economic exploitation of chickens was widely practiced. We base our claim on the exceptionally high frequency of chicken bones at that site, the majority of which belong to adult individuals, and on the observed 2:1 ratio of female to male bones. These results are supported further by an extensive survey of faunal remains from 234 sites in the Southern Levant, spanning more than three millennia, which shows a sharp increase in the frequency of chicken during the Hellenistic period. We further argue that the earliest secure evidence for economic exploitation of chickens in Europe dates to the first century B.C.E. and therefore is predated by the finds in the Southern Levant by at least a century. We suggest that the gradual acclimatization of chickens in the Southern Levant and its gradual integration into the local economy, the latter fully accomplished in the Hellenistic period, was a crucial step in the adoption of this species in European husbandry some 100 y later. PMID:26195775

  11. The Iranian Prehistoric Project: New problems arise as more is learned of the first attempts at food production and settled village life.

    PubMed

    Braidwood, R J; Howe, B; Reed, C A

    1961-06-23

    Many indications point toward the hill flanks of the Fertile Crescent in southwestern Asia as the scene of the earliest development of effective food production and a village-farming-community way of life, some 10,000 years ago or less. In its 1959-60 field season, with a staff made up of both cultural and natural historians, the Iranian Prehistoric Project reclaimed further evidence of this important transitional step in human history. This is a short interim report, based entirely on an in-the-field assessment of the materials.

  12. How did LUCA make a living? Chemiosmosis in the origin of life.

    PubMed

    Lane, Nick; Allen, John F; Martin, William

    2010-04-01

    Despite thermodynamic, bioenergetic and phylogenetic failings, the 81-year-old concept of primordial soup remains central to mainstream thinking on the origin of life. But soup is homogeneous in pH and redox potential, and so has no capacity for energy coupling by chemiosmosis. Thermodynamic constraints make chemiosmosis strictly necessary for carbon and energy metabolism in all free-living chemotrophs, and presumably the first free-living cells too. Proton gradients form naturally at alkaline hydrothermal vents and are viewed as central to the origin of life. Here we consider how the earliest cells might have harnessed a geochemically created proton-motive force and then learned to make their own, a transition that was necessary for their escape from the vents. Synthesis of ATP by chemiosmosis today involves generation of an ion gradient by means of vectorial electron transfer from a donor to an acceptor. We argue that the first donor was hydrogen and the first acceptor CO2.

  13. [A New Approach to Fostering Socio-Emotional Communication and Development in the Earliest Years of Life].

    ERIC Educational Resources Information Center

    Fenichel, Emily, Ed.

    1996-01-01

    The five articles in this newsletter theme issue focus on the development of socioemotional and communication skills in infants and toddlers through the Partners in Parenting Education (PIPE) program. The first article, "The Partners in Parenting Education Program: A New Option in Parent Education" (Perry M. Butterfield), describes the program's…

  14. The earliest settlers' antiquity and evolutionary history of Indian populations: evidence from M2 mtDNA lineage

    PubMed Central

    2008-01-01

    Background The "out of Africa" model postulating single "southern route" dispersal posits arrival of "Anatomically Modern Human" to Indian subcontinent around 66–70 thousand years before present (kyBP). However the contributions and legacy of these earliest settlers in contemporary Indian populations, owing to the complex past population dynamics and later migrations has been an issue of controversy. The high frequency of mitochondrial lineage "M2" consistent with its greater age and distribution suggests that it may represent the phylogenetic signature of earliest settlers. Accordingly, we attempted to re-evaluate the impact and contribution of earliest settlers in shaping the genetic diversity and structure of contemporary Indian populations; using our newly sequenced 72 and 4 published complete mitochondrial genomes of this lineage. Results The M2 lineage, harbouring two deep rooting subclades M2a and M2b encompasses approximately one tenth of the mtDNA pool of studied tribes. The phylogeographic spread and diversity indices of M2 and its subclades among the tribes of different geographic regions and linguistic phyla were investigated in detail. Further the reconstructed demographic history of M2 lineage as a surrogate of earliest settlers' component revealed that the demographic events with pronounced regional variations had played pivotal role in shaping the complex net of populations phylogenetic relationship in Indian subcontinent. Conclusion Our results suggest that tribes of southern and eastern region along with Dravidian and Austro-Asiatic speakers of central India are the modern representatives of earliest settlers of subcontinent. The Last Glacial Maximum aridity and post LGM population growth mechanised some sort of homogeneity and redistribution of earliest settlers' component in India. The demic diffusion of agriculture and associated technologies around 3 kyBP, which might have marginalized hunter-gatherer, is coincidental with the decline of

  15. Phytoliths reveal the earliest fine reedy textile in China at the Tianluoshan site

    PubMed Central

    Zhang, Jianping; Lu, Houyuan; Sun, Guoping; Flad, Rowan; Wu, Naiqin; Huan, Xiujia; He, Keyang; Wang, Yonglei

    2016-01-01

    Textiles are among the longest and most widespread technologies in human history, although poor preservation of perishable artifacts in Paleolithic and Neolithic contexts makes them difficult to unearth and has hampered study of their production and use. Here we report evidence of a plain-woven mat from the Tianluoshan site, Zhejiang, Eastern China. Phytolith and AMS dating from the mat and modern reference collections shown that the mat was made of reeds (Phragmites australis (Cav.)) and dated to 6775–6645 cal. yr. BP. This is the earliest directly dated fiber artifact so far known in China, over at least one thousand years earlier than any established dates for woven remains elsewhere. The evidence of the mat and other related remains suggest that textile products might occur earlier than 7000–8000 years ago and are significant for understanding the history of textiles, as well as production and human adaptation in Neolithic China. PMID:26766794

  16. Genotypic analysis of the earliest known prehistoric case of tuberculosis in Britain.

    PubMed

    Taylor, G Michael; Young, Douglas B; Mays, Simon A

    2005-05-01

    The earliest known case of human tuberculosis in Britain dates to the middle period of the Iron Age, approximately 2,200 years before present. Bone lesions on the spine of a male skeleton excavated at Tarrant Hinton in Dorset, United Kingdom, show evidence of Pott's disease and are supported by molecular evidence of Mycobacterium tuberculosis complex DNA amplified by IS6110 PCR (19). In the present study, we used a further series of sensitive PCR methods to confirm the diagnosis of tuberculosis and to determine the genotype of the infecting strain. These tests demonstrated that this individual was infected with a strain of M. tuberculosis rather than Mycobacterium bovis. The strain had undergone the tuberculosis D1 deletion affecting the mmpS6 and mmpL6 genes and can therefore be identified as a member of the family of "modern" M. tuberculosis isolates. All evidence obtained was consistent with surviving mycobacterial DNA being highly fragmented in this case.

  17. Phytoliths reveal the earliest fine reedy textile in China at the Tianluoshan site

    NASA Astrophysics Data System (ADS)

    Zhang, Jianping; Lu, Houyuan; Sun, Guoping; Flad, Rowan; Wu, Naiqin; Huan, Xiujia; He, Keyang; Wang, Yonglei

    2016-01-01

    Textiles are among the longest and most widespread technologies in human history, although poor preservation of perishable artifacts in Paleolithic and Neolithic contexts makes them difficult to unearth and has hampered study of their production and use. Here we report evidence of a plain-woven mat from the Tianluoshan site, Zhejiang, Eastern China. Phytolith and AMS dating from the mat and modern reference collections shown that the mat was made of reeds (Phragmites australis (Cav.)) and dated to 6775–6645 cal. yr. BP. This is the earliest directly dated fiber artifact so far known in China, over at least one thousand years earlier than any established dates for woven remains elsewhere. The evidence of the mat and other related remains suggest that textile products might occur earlier than 7000–8000 years ago and are significant for understanding the history of textiles, as well as production and human adaptation in Neolithic China.

  18. Climatic implications of latest Pleistocene and earliest Holocene mammalian sympatries in eastern Washington state, USA

    NASA Astrophysics Data System (ADS)

    Lyman, R. Lee

    2008-11-01

    For more than fifty years it has been known that mammalian faunas of late-Pleistocene age are taxonomically unique and lack modern analogs. It has long been thought that nonanalog mammalian faunas are limited in North America to areas east of the Rocky Mountains and that late-Pleistocene mammalian faunas in the west were modern in taxonomic composition. A late-Pleistocene fauna from Marmes Rockshelter in southeastern Washington State has no modern analog and defines an area of maximum sympatry that indicates significantly cooler summers than are found in the area today. An earliest Holocene fauna from Marmes Rockshelter defines an area of maximum sympatry, including the site area, but contains a single tentatively identified taxon that may indicate slightly cooler than modern summers.

  19. Biotic Response in Aquatic Reptiles (Testudines) during Earliest Eocene Climatic Warming

    NASA Astrophysics Data System (ADS)

    Holroyd, P. A.; Hutchison, J. H.

    2010-12-01

    The earliest Eocene is marked by significant events of global warming: the Paleocene-Eocene Thermal Maximum (PETM) at ~55.8 Ma and two short-lived events (ETM2 or Elmo and H2) approximately 2 Ma later. These environmental changes induced strong responses in the continental biota. Noteworthy changes in North American mid-latitude faunas and floras that are temporally correlated with earliest Eocene warming events include: increased diversity; turnover; and significant range changes, comprising both northward shifts in ranges of North American taxa as well as intercontinental dispersal across Holarctica. Evidence for these biotic changes comes directly from the fossil record and indirectly from phylogeographic analyses of molecular phylogenies of extant biota. To date, the stratigraphic record of biotic change has only been examined for the flora and terrestrial mammals. Data on reptiles and for continental aquatic systems are particularly lacking. In order to assess the impact of climate-mediated faunal change in aquatic systems during early Paleogene warming, we have focused on developing a detailed record of fossil turtles (Testudines) from the Bighorn Basin of Wyoming, where these records can be directly compared to similarly studied mammalian and floral data and to isotopic studies that provide independent proxies of climate change. Using genus-level occurrence data from more than 450 stratigraphically-constrained localities spanning ~2.5 Ma, we calculated first and last appearances, taxonomic richness, and relative abundance as measured by presence-absence (site occupancy). Among turtles, taxonomic richness increased episodically through the earliest Eocene with two new taxa appearing at the PETM, two immediately following it, and two at Biohorizon B, an interval associated with the younger hyperthermals. These new, immigrant taxa eventually comprised 40% of known generic richness. Phylogenetically, the inferred biogeographic source regions are southern North

  20. Earliest known coelacanth skull extends the range of anatomically modern coelacanths to the Early Devonian.

    PubMed

    Zhu, Min; Yu, Xiaobo; Lu, Jing; Qiao, Tuo; Zhao, Wenjin; Jia, Liantao

    2012-04-10

    Coelacanths are known for their evolutionary conservatism, and the body plan seen in Latimeria can be traced to late Middle Devonian Diplocercides, Holopterygius and presumably Euporosteus. However, the group's early history is unclear because of an incomplete fossil record. Until now, the only Early Devonian coelacanth is an isolated dentary (Eoactinistia) from Australia, whose position within the coelacanths is unknown. Here we report the earliest known coelacanth skull (Euporosteus yunnanensis sp. nov.) from the Early Devonian (late Pragian) of Yunnan, China. Resolved by maximum parsimony, maximum likelihood and Bayesian analyses as crownward of Diplocercides or as its sister taxon, the new form extends the chronological range of anatomically modern coelacanths by about 17 Myr. The finding lends support to the possibility that Eoactinistia is also an anatomically modern coelacanth, and provides a more refined reference point for studying the rapid early diversification and subsequent evolutionary conservatism of the coelacanths.

  1. Paleoenvironment of the earliest hominoids: new evidence from the oligocene avifauna of egypt.

    PubMed

    Olson, S L; Rasmussén, D T

    1986-09-12

    Analysis of fossil birds from the Oligocene Jebel Qatrani Formation in the Fayum depression of Egypt, site of the oldest known hominoid primates, allows precise paleoenvironmental reconstruction of the climatic and biotic conditions that influenced some of the earliest stages of hominoid evolution. Unlike the fossil mammals of the Fayum, which belong largely to extinct groups, most of the birds are referable to living families, with some being close to modern genera. The avifauna consists mainly of aquatic species, with such forms as jacanas (Jacanidae) and shoebilled storks (Balaenicipitidae) indicating expanses of freshwater with dense floating vegetation. An avifauna closely analogous to that of the Fayum is found today only in a limited area of Uganda, north and west of Lake Victoria, a region of swampland bordered by forest and grasslands that presents marked faunal similarities to the environment inferred for the Egyptian Oligocene.

  2. The termites of Early Eocene Cambay amber, with the earliest record of the Termitidae (Isoptera).

    PubMed

    Engel, Michael S; Grimaldi, David A; Nascimbene, Paul C; Singh, Hukam

    2011-01-01

    The fauna of termites (Isoptera) preserved in Early Eocene amber from the Cambay Basin (Gujarat, India) are described and figured. Three new genera and four new species are recognized, all of them Neoisoptera - Parastylotermes krishnai Engel & Grimaldi, sp. n. (Stylotermitidae); Prostylotermes kamboja Engel & Grimaldi, gen. et sp. n. (Stylotermitidae?); Zophotermes Engel, gen. n., with Zophotermes ashoki Engel & Singh, sp. n. (Rhinotermitidae: Prorhinotermitinae); and Nanotermes isaacae Engel & Grimaldi, gen. et sp. n. (Termitidae: Termitinae?). Together these species represent the earliest Tertiary records of the Neoisoptera and the oldest definitive record of Termitidae, a family that comprises >75% of the living species of Isoptera. Interestingly, the affinities of the Cambay amber termites are with largely Laurasian lineages, in this regard paralleling relationships seen between the fauna of bees and some flies. Diversity of Neoisoptera in Indian amber may reflect origin of the amber deposit in Dipterocarpaceae forests formed at or near the paleoequator.

  3. Phytoliths reveal the earliest fine reedy textile in China at the Tianluoshan site.

    PubMed

    Zhang, Jianping; Lu, Houyuan; Sun, Guoping; Flad, Rowan; Wu, Naiqin; Huan, Xiujia; He, Keyang; Wang, Yonglei

    2016-01-14

    Textiles are among the longest and most widespread technologies in human history, although poor preservation of perishable artifacts in Paleolithic and Neolithic contexts makes them difficult to unearth and has hampered study of their production and use. Here we report evidence of a plain-woven mat from the Tianluoshan site, Zhejiang, Eastern China. Phytolith and AMS dating from the mat and modern reference collections shown that the mat was made of reeds (Phragmites australis (Cav.)) and dated to 6775-6645 cal. yr. BP. This is the earliest directly dated fiber artifact so far known in China, over at least one thousand years earlier than any established dates for woven remains elsewhere. The evidence of the mat and other related remains suggest that textile products might occur earlier than 7000-8000 years ago and are significant for understanding the history of textiles, as well as production and human adaptation in Neolithic China.

  4. The Earliest Thymic T Cell Progenitors Sustain B Cell and Myeloid Lineage Potentials

    PubMed Central

    Luc, Sidinh; Luis, Tiago C.; Boukarabila, Hanane; Macaulay, Iain C.; Buza-Vidas, Natalija; Bouriez-Jones, Tiphaine; Lutteropp, Michael; Woll, Petter S.; Loughran, Stephen J.; Mead, Adam J.; Hultquist, Anne; Brown, John; Mizukami, Takuo; Matsuoka, Sahoko; Ferry, Helen; Anderson, Kristina; Duarte, Sara; Atkinson, Deborah; Soneji, Shamit; Domanski, Aniela; Farley, Alison; Sanjuan-Pla, Alejandra; Carella, Cintia; Patient, Roger; de Bruijn, Marella; Enver, Tariq; Nerlov, Claus; Blackburn, Clare; Godin, Isabelle; Jacobsen, Sten Eirik W.

    2012-01-01

    The stepwise commitment from hematopoietic stem cells in the bone marrow (BM) to T lymphocyte-restricted progenitors in the thymus represents a paradigm for understanding the requirement for distinct extrinsic cues during different stages of lineage restriction from multipotent to lineage restricted progenitors. However, the commitment stage at which progenitors migrate from the BM to the thymus remains unclear. Here we provide functional and molecular evidence at the single cell level that the earliest progenitors in the neonatal thymus possessed combined granulocyte-monocyte, T and B lymphocyte, but not megakaryocyte-erythroid lineage potential. These potentials were identical to those of thymus-seeding progenitors in the BM, which were closely related at the molecular level. These findings establish the distinct lineage-restriction stage at which the T lineage commitment transits from the BM to the remote thymus. PMID:22344248

  5. Earliest crinoids: New evidence for the origin of the dominant Paleozoic echinoderms

    NASA Astrophysics Data System (ADS)

    Guensburg, Thomas E.; Sprinkle, James

    2001-02-01

    The oldest crinoids have been discovered in Early Ordovician strata of the western United States. A set of emergent crinoid traits based on these and other early crinoids enables reinterpretation of crinoid origins and early history. The new fossils retain primitive echinoderm characteristics, including ambulacral floor plates and largely unorganized cup plating, a first for crinoids. They lack shared derived characteristics linking them to other stalked echinoderms, including blastozoans. Contrary to current widespread opinion, crinoids originated as an independent group during the Cambrian, apparently from an edrioasteroid ancestor. All four major Paleozoic crinoid clades had evolved by the early Ibexian (Tremadocian), and this initial diversification slightly preceded those of most other Paleozoic evolutionary fauna components. These earliest crinoids attached to carbonate hardgrounds developed on sponge-algal mounds, intraformational conglomerates, and grainstones.

  6. Earliest record of the invasive Foraminifera Trochammina hadai in San Francisco Bay, California, USA

    USGS Publications Warehouse

    McGann, Mary

    2014-01-01

    In 1995, Trochammina hadai, a benthic Foraminifera prevalent in Japanese estuaries, was found in San Francisco Bay, California, USA. Subsequent field investigations determined that the species was also present in nearly all of the major ports and estuaries along the western United States. Because of its widespread colonization, it is of interest to determine when T. hadai first appeared as an invasive in the coastal regions of the North Pacific. In San Francisco Bay, the species was not found in 404 surface samples collected between 1930 and 1981. In 1983, however, a grab sediment sample from one of four sites in the southern portion of the bay contained T. hadai. This site was the most northern of the four and contained 12 specimens of the invasive, comprising 1.5% of the assemblage. This is the earliest appearance on record of T. hadai in San Francisco Bay.

  7. Eocene fossil is earliest evidence of flower-visiting by birds.

    PubMed

    Mayr, Gerald; Wilde, Volker

    2014-05-01

    Birds are important pollinators, but the evolutionary history of ornithophily (bird pollination) is poorly known. Here, we report a skeleton of the avian taxon Pumiliornis from the middle Eocene of Messel in Germany with preserved stomach contents containing numerous pollen grains of an eudicotyledonous angiosperm. The skeletal morphology of Pumiliornis is in agreement with this bird having been a, presumably nectarivorous, flower-visitor. It represents the earliest and first direct fossil evidence of flower-visiting by birds and indicates a minimum age of 47 million years for the origin of bird-flower interactions. As Pumiliornis does not belong to any of the modern groups of flower-visiting birds, the origin of ornithophily in some angiosperm lineages may have predated that of their extant avian pollinators.

  8. Bivalves from the latest Jurassic-earliest Cretaceous hydrocarbon seep carbonates from central Spitsbergen, Svalbard.

    PubMed

    Hryniewicz, Krzysztof; Little, Crispin T S; Nakrem, Hans Arne

    2014-09-02

    The bivalve fauna from the latest Jurassic-earliest Cretaceous hydrocarbon seep deposits from central Spitsbergen, Svalbard comprises at least 17 species, four of which belong to chemosymbiotic taxa often found at seeps. These are the solemyid Solemya (Petrasma) cf. woodwardiana; Nucinella svalbardensis sp. nov., which belongs to a group of large Nucinella species known from seeps and deep water environments; the lucinid bivalve, Tehamatea rasmusseni sp. nov., included in a genus widely distributed in other Jurassic-Cretaceous seeps; and Cretaxinus hurumi gen. et sp. nov., which is the oldest known thyasirid and is discussed in relation to other large seep-restricted genera in this family. The remaining species in the fauna belong to 'background' genera known from coeval normal marine sediments, mostly from the Boreal area. These include the nuculid Dacromya chetaensis, two new malletiids (Mesosaccella rogovi sp. nov. and M. toddi sp. nov.), the oxytomiid Oxytoma octavia, at least three Buchia species, at least two pectinids, including Camptonectes (Costicamptonectes) aff. milnelandensis and Camptonectes (Camptochlamys) clatrathus, the limid Pseudolimea arctica, the arcticid Pseudotrapezium aff. groenlandicum, and the pholadomyid Goniomya literata. The large number of 'background' species in the bivalve fauna is probably a reflection of the shallow-water setting of the Svalbard seeps. This might also explain the lack of the seep-restricted modiomorphid bivalve Caspiconcha from the fauna. With solemyids, Nucinella, lucinids and thyasirids, the latest Jurassic-earliest Cretaceous bivalve seep fauna of Svalbard contains typical representatives of the Mesozoic bivalve seep faunas, both long established and young evolutionary colonists.

  9. Volutidae (Mollusca: Gastropoda) of the Lakhra Formation (Earliest Eocene, Sindh, Pakistan): systematics, biostratigraphy and paleobiogeography.

    PubMed

    Merle, Didier; Pacaud, Jean-Michel; Métais, Grégoire; Bartolini, Annachiara; Lashari, Rafiq A; Brohi, Imdad A; Solangi, Sarfraz H; Marivaux, Laurent; Welcomme, Jean-Loup

    2014-06-27

    The paleobiodiversity of the Volutidae (Mollusca: Gastropoda) of the Ranikot Group (Sindh, Pakistan) and particularly of the Lakhra Formation (SBZ 5 biozone, Earliest Eocene), is reconsidered on the basis of new material collected during recent field trips. Ten new species are described (Mitreola brohii sp. nov., Lyrischapa vredenburgi sp. nov., L. brevispira sp. nov., Athleta (Volutopupa) citharopsis sp. nov., A. (Volutocorbis) lasharii sp. nov., Volutilithes welcommei sp. nov., V. sindhiensis sp. nov., Pseudaulicina coxi sp. nov., Sindhiluta lakhraensis sp. nov. and Pakiluta solangii sp. nov.) and one species is in open nomenclature (Lyria sp.). Three new genera are described: Lyriopsis gen. nov. [Volutinae, ?Lyriini, type species: Lyriopsis cossmanni (Vredenburg, 1923)], Sindhiluta gen. nov. [Volutilithinae, type species: Sindhiluta lakhraensis n. sp.] and Pakiluta gen. nov. [?Volutodermatinae, type species: Pakiluta solangii n. sp.]. Two new combinations are proposed: Lyriopsis cossmanni (Vredenburg, 1923) comb. nov. and Athleta (Volutopupa) intercrenatus (Cossmann & Pissarro, 1909) comb. nov. Lectotypes are designated for Lyria cossmanni Vredenburg, 1923, L. feddeni Vredenburg, 1923, Volutospina noetlingi Cossmann & Pissarro, 1909, V. intercrenata Cossmann & Pissarro, 1909 and Athleta (Volutocorbis) victoriae Vredenburg, 1923. With 21 species, this volutid fauna is the most diverse recorded from the Tethys Ocean during Earliest Eocene time. The assemblage is characterized by a strong turnover marked by regional speciation and the appearance of many western Tethyan invaders. Although at the species level, the assemblage documents a strong provincialism, at the genus level, the high number of shared genera between Eastern Tethyan and Old World Tethyan realms begins a phase of long-term homogeneity of volutid assemblages from the Tethyan paleobiogeographic province.

  10. Nonmarine stromatolites and the search for early life on Mars

    NASA Technical Reports Server (NTRS)

    Awramik, S. M.

    1991-01-01

    The available evidence permits one to conclude that streams flowed and lakes developed on Mars sometime in the remote past. The lessons learned from the Earth's earliest fossil record suggest that stromatolites might have formed on Mars, speculating that: (1) biopoesis occurred on Mars during its earliest history; (2) life evolved and diversified; (3) life inhabited aqueous environments; and (4) sunlight was an important environmental resource. The most likely place to find stromatolites and possibly microbial fossils on Mars would be in ancient lake and stream deposits. If thermal spring deposits can be identified, then they too are sites for biogeological investigations. Other aspects of this study are presented.

  11. When cats' ways of life interact with their viruses: a study in 15 natural populations of owned and unowned cats (Felis silvestris catus).

    PubMed

    Hellard, E; Fouchet, D; Santin-Janin, H; Tarin, B; Badol, V; Coupier, C; Leblanc, G; Poulet, H; Pontier, D

    2011-09-01

    In natural populations, virus circulation is influenced by host behavior and physiological characteristics. Cat populations exhibit a great variability in social and spatial structure, the existence of different ways of life within a same population may also result in different epidemiological patterns. To test this hypothesis, we used a logistic regression to analyze the risk factors of Feline immunodeficiency virus (FIV), feline herpes virus (FHV), feline calicivirus (FCV), and feline parvovirus (FPV) infection in owned (fed and sheltered) and unowned (neither fed nor sheltered, unsocialized) cats living in a rural environment in the North Eastern part of France. A serological survey was carried out in 492 non-vaccinated and non-sterilized individuals from 15 populations living in the same area. The prevalence of feline leukemia virus (FeLV) was also studied, but too few were infected to analyze the risk factors of this virus. For each virus, the epidemiological pattern was different in owned and unowned cats. Unowned cats were more frequently infected by directly transmitted viruses like FIV, FHV and FCV (21.22%, 67.66%, 86.52% in unowned cats vs 9.55%, 53.88%, 77.18% in owned cats, respectively), a difference that may be explained by a more solitary and more aggressive behavior in unowned adults, and/or possibly by a higher sensitivity related to a more stressful life. On the contrary, owned cats were more frequently infected with FPV (36.41% in owned cats vs 15.61% in unowned cats), possibly as a result of their concentration around human settlements. The present study showed that owned and unowned cats living in a same area have behavioral and physiological characteristics sufficiently different to influence virus circulation. Pooling different types of cats in a single sample without taking it into account could give a wrong picture of the epidemiology of their viruses. The conclusion of this work can be extended to any epidemiological studies led in

  12. AIRUSE-LIFE +: estimation of natural source contributions to urban ambient air PM10 and PM2. 5 concentrations in southern Europe - implications to compliance with limit values

    NASA Astrophysics Data System (ADS)

    Diapouli, Evangelia; Manousakas, Manousos I.; Vratolis, Stergios; Vasilatou, Vasiliki; Pateraki, Stella; Bairachtari, Kyriaki A.; Querol, Xavier; Amato, Fulvio; Alastuey, Andrés; Karanasiou, Angeliki A.; Lucarelli, Franco; Nava, Silvia; Calzolai, Giulia; Gianelle, Vorne L.; Colombi, Cristina; Alves, Célia; Custódio, Danilo; Pio, Casimiro; Spyrou, Christos; Kallos, George B.; Eleftheriadis, Konstantinos

    2017-03-01

    The contribution of natural sources to ambient air particulate matter (PM) concentrations is often not considered; however, it may be significant for certain areas and during specific periods of the year. In the framework of the AIRUSE-LIFE+ project, state-of-the-art methods have been employed for assessing the contribution of major natural sources (African dust, sea salt and forest fires) to PM concentrations, in southern European urban areas. 24 h measurements of PM10 and PM2. 5 mass and chemical composition were performed over the course of a year in five cities: Porto, Barcelona, Milan, Florence and Athens. Net African dust and sea-salt concentrations were calculated based on the methodologies proposed by the EC (SEC 2011/208). The contribution of uncontrolled forest fires was calculated through receptor modelling. Sensitivity analysis with respect to the calculation of African dust was also performed, in order to identify major parameters affecting the estimated net dust concentrations. African dust contribution to PM concentrations was more pronounced in the eastern Mediterranean, with the mean annual relative contribution to PM10 decreasing from 21 % in Athens, to 5 % in Florence, and around 2 % in Milan, Barcelona and Porto. The respective contribution to PM2. 5 was calculated equal to 14 % in Athens and from 1.3 to 2.4 % in all other cities. High seasonal variability of contributions was observed, with dust transport events occurring at different periods in the western and eastern Mediterranean basin. Sea salt was mostly related to the coarse mode and also exhibited significant seasonal variability. Sea-salt concentrations were highest in Porto, with average relative contributions equal to 12.3 % for PM10. Contributions from uncontrolled forest fires were quantified only for Porto and were low on an annual basis (1.4 and 1.9 % to PM10 and PM2. 5, respectively); nevertheless, contributions were greatly increased during events, reaching 20 and 22 % of 24 h

  13. Precise U-Pb Zircon Constraints on the Earliest Magmatic History of the Carolina Terrane.

    PubMed

    Wortman; Samson; Hibbard

    2000-05-01

    The early magmatic and tectonic history of the Carolina terrane and its possible affinities with other Neoproterozoic circum-Atlantic arc terranes have been poorly understood, in large part because of a lack of reliable geochronological data. Precise U-Pb zircon dates for the Virgilina sequence, the oldest exposed part, constrain the timing of the earliest known stage of magmatism in the terrane and of the Virgilina orogeny. A flow-banded rhyolite sampled from a metavolcanic sequence near Chapel Hill, North Carolina, yielded a U-Pb zircon date of 632.9 +2.6/-1.9 Ma. A granitic unit of the Chapel Hill pluton, which intrudes the metavolcanic sequence, yielded a nearly identical U-Pb zircon date of 633 +2/-1.5 Ma, interpreted as its crystallization age. A felsic gneiss and a dacitic tuff from the Hyco Formation yielded U-Pb zircon dates of 619.9 +4.5/-3 Ma and 615.7 +3.7/-1.9 Ma, respectively. Diorite and granite of the Flat River complex have indistinguishable U-Pb upper-intercept dates of 613.9 +1.6/-1.5 Ma and 613.4 +2.8/-2 Ma. The Osmond biotite-granite gneiss, which intruded the Hyco Formation before the Virgilina orogeny, crystallized at 612.4 +5.2/-1.7 Ma. Granite of the Roxboro pluton, an intrusion that postdated the Virgilina orogeny, yielded a U-Pb upper intercept date of 546.5 +3.0/-2.4 Ma, interpreted as the time of its crystallization. These new dates both provide the first reliable estimates of the age of the Virgilina sequence and document that the earliest known stage of magmatism in the Carolina terrane had begun by 633 +2/-1.5 Ma and continued at least until 612.4 +5.2/-1.7 Ma, an interval of approximately 25 m.yr. Timing of the Virgilina orogeny is bracketed between 612.4 +5.2/-1.7 Ma and 586+/-10 Ma (reported age of the upper Uwharrie Formation). The U-Pb systematics of all units studied in the Virgilina sequence are simple and lack any evidence of an older xenocrystic zircon component, which would indicate the presence of a continental

  14. The Earliest Chinese Proto-Porcelain Excavated from Kiln Sites: An Elemental Analysis

    PubMed Central

    Li, Yu; Zhang, Bin; Cheng, Huansheng; Zheng, Jianming

    2015-01-01

    In June 2012, the Piaoshan kiln site was excavated in Huzhou, Zhejiang Province, which hitherto proved to be the earliest known Chinese proto-porcelain kiln. Judging from the decorative patterns of unearthed impressed stoneware and proto-porcelain sherds, the site was determined to date to the late Xia (c. 2070–c. 1600 BC), the first dynasty of China. Here, we report on proton-induced X-ray emission analyses of 118 proto-porcelain and 35 impressed stoneware sherds from Piaoshan and five subsequent kiln sites in the vicinity. Using principal components analysis on the major chemical compositions, we reveal the relationships between impressed stoneware and proto-porcelain samples from the six kiln sites. The sherds from different sites have distinctive chemical profiles. The results indicate that the raw materials were procured locally. We find a developmental tendency for early glazes towards mature calcium-based glaze. It is most likely that woody plant ashes with increased calcia-potash ratios were applied to the formula. PMID:26535583

  15. Earliest and first Northern Hemispheric hoatzin fossils substantiate Old World origin of a "Neotropic endemic".

    PubMed

    Mayr, Gerald; De Pietri, Vanesa L

    2014-02-01

    The recent identification of hoatzins (Opisthocomiformes) in the Miocene of Africa showed part of the evolution of these birds, which are now only found in South America, to have taken place outside the Neotropic region. Here, we describe a new fossil species from the late Eocene of France, which constitutes the earliest fossil record of hoatzins and the first one from the Northern Hemisphere. Protoazin parisiensis gen. et sp. nov. is more closely related to South American Opisthocomiformes than the African taxon Namibiavis and substantiates an Old World origin of hoatzins, as well as a relictual distribution of the single extant species. Although recognition of hoatzins in Europe may challenge their presumed transatlantic dispersal, there are still no North American fossils in support of an alternative, Northern Hemispheric, dispersal route. In addition to Opisthocomiformes, other avian taxa are known from the Cenozoic of Europe, the extant representatives of which are only found in South America. Recognition of hoatzins in the early Cenozoic of Europe is of particular significance because Opisthocomiformes have a fossil record in sub-Saharan Africa, which supports the hypothesis that extinction of at least some of these "South American" groups outside the Neotropic region was not primarily due to climatic factors.

  16. Myocardin marks the earliest cardiac gene expression and plays an important role in heart development.

    PubMed

    Chen, Jian-Fu; Wang, Shusheng; Wu, Qiulian; Cao, Dongsun; Nguyen, Thiha; Chen, Yiping; Wang, Da-Zhi

    2008-10-01

    Myocardin belongs to the SAP domain family of transcription factors and is expressed specifically in cardiac and smooth muscle during embryogenesis and in adulthood. Myocardin functions as a transcriptional coactivator of SRF and is sufficient and necessary for smooth muscle gene expression. However, the in vivo function of myocardin during cardiogenesis is not completely understood. Here we clone myocardin from chick embryonic hearts and show that myocardin protein sequences are highly conserved cross species. Detailed studies of chick myocardin expression reveal that myocardin is expressed in cardiac and smooth muscle lineage during early embryogenesis, similar to that found in mouse. Interestingly, the expression of myocardin in the heart was found enriched in the outflow tract and the sinoatrial segments shortly after the formation of linear heart tube. Such expression pattern is also maintained in later developing embryos, suggesting that myocardin may play a unique role in the formation of those cardiac modules. Similar to its mouse counterpart, chick myocardin is able to activate cardiac and smooth muscle promoter reporter genes and induce smooth muscle gene expression in nonmuscle cells. Ectopic overexpression of myocardin enlarged the embryonic chick heart. Conversely, repression of the endogenous chick myocardin using antisense oligonucleotides or a dominant negative mutant form of myocardin inhibited cardiogenesis. Together, our data place myocardin as one of the earliest cardiac marker genes for cardiogenesis and support the idea that myocardin plays an essential role in cardiac gene expression and cardiogenesis.

  17. Genomic evidence for plant-parasitic nematodes as the earliest Wolbachia hosts

    PubMed Central

    Brown, Amanda M. V.; Wasala, Sulochana K.; Howe, Dana K.; Peetz, Amy B.; Zasada, Inga A.; Denver, Dee R.

    2016-01-01

    Wolbachia, one of the most widespread endosymbionts, is a target for biological control of mosquito-borne diseases (malaria and dengue virus), and antibiotic elimination of infectious filarial nematodes. We sequenced and analyzed the genome of a new Wolbachia strain (wPpe) in the plant-parasitic nematode Pratylenchus penetrans. Phylogenomic analyses placed wPpe as the earliest diverging Wolbachia, suggesting two evolutionary invasions into nematodes. The next branches comprised strains in sap-feeding insects, suggesting Wolbachia may have first evolved as a nutritional mutualist. Genome size, protein content, %GC, and repetitive DNA allied wPpe with mutualistic Wolbachia, whereas gene repertoire analyses placed it between parasite (A, B) and mutualist (C, D, F) groups. Conservation of iron metabolism genes across Wolbachia suggests iron homeostasis as a potential factor in its success. This study enhances our understanding of this globally pandemic endosymbiont, highlighting genetic patterns associated with host changes. Combined with future work on this strain, these genomic data could help provide potential new targets for plant-parasitic nematode control. PMID:27734894

  18. The proterozoic and earliest cambrian trace fossil record; patterns, problems and perspectives.

    PubMed

    Jensen, Sören

    2003-02-01

    The increase in trace fossil diversity across the Neoproterozoic-Cambrian boundary often is presented in terms of tabulations of ichnogenera. However, a clearer picture of the increase in diversity and complexity can be reached by combining trace fossils into broad groups defined both on morphology and interpretation. This also focuses attention on looking for similarites between Neoproterozoic and Cambrian trace fossils. Siliciclastic sediments of the Neoproterozoic preserve elongate tubular organisms and structures of probable algal origin, many of which are very similar to trace fossils. Such enigmatic structures include Palaeopascichnus and Yelovichnus, previously thought to be trace fossils in the form of tight meanders.A preliminary two or tripartite terminal Neoproterozoic trace fossil zonation can be be recognized. Possibly the earliest trace fossils are short unbranched forms, probably younger than about 560 Ma. Typical Neoproterozoic trace fossils are unbranched and essentially horizontal forms found associated with diverse assemblages of Ediacaran organisms. In sections younger than about 550 Ma a modest increase in trace fossil diversity occurs, including the appearance of rare three-dimensional burrow systems (treptichnids), and traces with a three-lobed lower surfaces.

  19. The earliest mollusc dominated seep fauna from the Early Jurassic of Argentina

    NASA Astrophysics Data System (ADS)

    Kaim, Andrzej; Jenkins, Robert; Parent, Horacio; Garrido, Alberto; Moriya, Kazuhiro

    2015-04-01

    The earliest mollusc dominated seep fauna from the Early Jurassic of Argentina Andrzej Kaim, Robert G. Jenkins, Horacio Parent, Alberto C. Garrido The hydrocarbon seep deposits are known from Early Jurassic of Argentina since the report of Gomez-Perez (2003). The latter author identified very negative δ13C values (down to -33) and several fabrics typical for seep carbonates. Nevertheless she identified no macrofaunal assemblages apart from worm tubes. We re-visited the locality of Gomez-Perez (named here La Elina) and we were able to collect several molluscs associated with the seep carbonate. The most common and diversified are molluscs and worm tubes. We identified at least three species of gastropods, including the oldest-known species of neomphalids, lucinid and protobranch bivalves and numerous ammonoids. Unlike another known Early Jurassic seep from Oregon and the only Late Triassic seep (also from Oregon) there are no brachiopods associated with this seep. Therefore we consider the seep at La Elina as the oldest seep of modern aspect where the fauna is dominated by molluscs and not brachiopods.

  20. Earliest foraminifera and radiolaria from North America: evolutionary and geological implications

    SciTech Connect

    Lipps, J.H.

    1985-01-01

    Foraminifera and radiolaria were found in lower and middle Cambrian rocks in the western US. They occur in clastic rocks associated with archaeocyathid bioherms and shales in SE California, SW Nevada, W Utah and Idaho. The foraminifera are agglutinated tubes, straight or coiled; the radiolaria are spherical or flattened wit robust lattices. They occur together with some of the earliest shelled metazoa. Their widespread occurrence indicates that protozoa were important elements of the first animal-dominated communities. Their presence suggests a complex trophic structure involving secondary consumers that utilized small autotrophs, carnivores, and detritus. Ordovician and Silurian foraminifera and radiolaria, also found in the US and USSR, show that the subsequent radiation of heterotrophic protists follows a pattern similar to that of metazoans. These fossil protozoa indicate that the skeletonization of early organisms was controlled by factors not related solely to a multicellular grade of organization. Hypotheses requiring the attainment of atmospheric oxygen levels high enough for metazoan skeletonization processes to operate, seawater chemistry allowing the use of specific skeletal materials, attainment of large size, evolution of regulatory genes, and similar ideas can be eliminated or modified. The fossils also indicate that the advent of skeletonized metazoa and protists, and their subsequent radiation were probably related to the proliferation of trophic interactions within those early communities.

  1. The Earliest Chinese Proto-Porcelain Excavated from Kiln Sites: An Elemental Analysis.

    PubMed

    Li, Yu; Zhang, Bin; Cheng, Huansheng; Zheng, Jianming

    2015-01-01

    In June 2012, the Piaoshan kiln site was excavated in Huzhou, Zhejiang Province, which hitherto proved to be the earliest known Chinese proto-porcelain kiln. Judging from the decorative patterns of unearthed impressed stoneware and proto-porcelain sherds, the site was determined to date to the late Xia (c. 2070-c. 1600 BC), the first dynasty of China. Here, we report on proton-induced X-ray emission analyses of 118 proto-porcelain and 35 impressed stoneware sherds from Piaoshan and five subsequent kiln sites in the vicinity. Using principal components analysis on the major chemical compositions, we reveal the relationships between impressed stoneware and proto-porcelain samples from the six kiln sites. The sherds from different sites have distinctive chemical profiles. The results indicate that the raw materials were procured locally. We find a developmental tendency for early glazes towards mature calcium-based glaze. It is most likely that woody plant ashes with increased calcia-potash ratios were applied to the formula.

  2. Origin and timing of New Zealand's earliest domestic chickens: Polynesian commensals or European introductions?

    PubMed Central

    Wood, Jamie R.; Herrera, Michael J. B.; Wilmshurst, Janet M.

    2016-01-01

    Human settlers transported chickens (Gallus gallus domesticus) to most East Polynesian archipelagos between AD 1000 and 1300; however, it has long been assumed that New Zealand was an exception. Despite the fact that chicken bones have been recovered from localities of early archaeological middens in New Zealand, their age and genetic relationships have never been critically assessed. Here, we test the assumption that chickens were not introduced to New Zealand during prehistory through ancient DNA and radiocarbon analyses of chicken bones from sites of Māori middens containing prehistoric material. The chickens belong to the widespread mitochondrial control region haplogroup E. Radiocarbon dating reveals that the bones are not prehistoric, but are still the earliest chicken remains known from New Zealand. Two of the bones pre-date permanent European settlement (ca 1803s onwards) but overlap with the arrival of James Cook's second voyage (1773–1774), and, therefore, they are likely to be chickens, or progeny thereof, liberated during that voyage. Our results support the idea that chickens were first introduced to New Zealand by Europeans, and provide new insights into Māori uptake and integration of resources introduced during the early post-European period. PMID:27853601

  3. Origin and timing of New Zealand's earliest domestic chickens: Polynesian commensals or European introductions?

    NASA Astrophysics Data System (ADS)

    Wood, Jamie R.; Herrera, Michael J. B.; Scofield, R. Paul; Wilmshurst, Janet M.

    2016-08-01

    Human settlers transported chickens (Gallus gallus domesticus) to most East Polynesian archipelagos between AD 1000 and 1300; however, it has long been assumed that New Zealand was an exception. Despite the fact that chicken bones have been recovered from localities of early archaeological middens in New Zealand, their age and genetic relationships have never been critically assessed. Here, we test the assumption that chickens were not introduced to New Zealand during prehistory through ancient DNA and radiocarbon analyses of chicken bones from sites of Māori middens containing prehistoric material. The chickens belong to the widespread mitochondrial control region haplogroup E. Radiocarbon dating reveals that the bones are not prehistoric, but are still the earliest chicken remains known from New Zealand. Two of the bones pre-date permanent European settlement (ca 1803s onwards) but overlap with the arrival of James Cook's second voyage (1773-1774), and, therefore, they are likely to be chickens, or progeny thereof, liberated during that voyage. Our results support the idea that chickens were first introduced to New Zealand by Europeans, and provide new insights into Māori uptake and integration of resources introduced during the early post-European period.

  4. Earliest evidence of dental caries manipulation in the Late Upper Palaeolithic

    PubMed Central

    Oxilia, Gregorio; Peresani, Marco; Romandini, Matteo; Matteucci, Chiara; Spiteri, Cynthianne Debono; Henry, Amanda G.; Schulz, Dieter; Archer, Will; Crezzini, Jacopo; Boschin, Francesco; Boscato, Paolo; Jaouen, Klervia; Dogandzic, Tamara; Broglio, Alberto; Moggi-Cecchi, Jacopo; Fiorenza, Luca; Hublin, Jean-Jacques; Kullmer, Ottmar; Benazzi, Stefano

    2015-01-01

    Prehistoric dental treatments were extremely rare, and the few documented cases are known from the Neolithic, when the adoption of early farming culture caused an increase of carious lesions. Here we report the earliest evidence of dental caries intervention on a Late Upper Palaeolithic modern human specimen (Villabruna) from a burial in Northern Italy. Using Scanning Electron Microscopy we show the presence of striations deriving from the manipulation of a large occlusal carious cavity of the lower right third molar. The striations have a “V”-shaped transverse section and several parallel micro-scratches at their base, as typically displayed by cutmarks on teeth. Based on in vitro experimental replication and a complete functional reconstruction of the Villabruna dental arches, we confirm that the identified striations and the associated extensive enamel chipping on the mesial wall of the cavity were produced ante-mortem by pointed flint tools during scratching and levering activities. The Villabruna specimen is therefore the oldest known evidence of dental caries intervention, suggesting at least some knowledge of disease treatment well before the Neolithic. This study suggests that primitive forms of carious treatment in human evolution entail an adaptation of the well-known toothpicking for levering and scratching rather than drilling practices. PMID:26179739

  5. The earliest fossil record of Panorpidae (Mecoptera) from the Middle Jurassic of China

    PubMed Central

    Ding, He; Shih, Chungkun; Bashkuev, Alexei; Zhao, Yunyun; Ren, Dong

    2014-01-01

    Abstract The early history of Panorpidae (Mecoptera) is poorly known due to sparse fossil records. Up to date, only nine fossil species have been described, all from the Paleogene, except the Early Cretaceous Solusipanorpa gibbidorsa Lin, 1980. However, we suggest S. gibbidorsa is too incompletely preserved to permit even family classification. A new genus with two new species, Jurassipanorpa impunctata gen. et sp. n. and Jurassipanorpa sticta sp. n., are described based on four well-preserved specimens from the late Middle Jurassic Jiulongshan Formation of Daohugou, Inner Mongolia, China. These two new species are the earliest fossil records of Panorpidae. The new genus is erected based on a combination of forewing characters: both R1 and Rs1 with two branches, 1A reaching posterior margin of wing distad of the forking of Rs from R1, and no crossveins or only one crossvein between veins of 1A and 2A. In all four specimens, long and robust setae ranging from 0.09 to 0.38 mm in length and pointing anteriorly, are present on anal veins of forewings. The function of these setae is enigmatic. PMID:25152669

  6. Ancestral feeding state of ruminants reconsidered: earliest grazing adaptation claims a mixed condition for Cervidae

    PubMed Central

    2008-01-01

    Background Specialised leaf-eating is almost universally regarded as the ancestral state of all ruminants, yet little evidence can be cited in support of this assumption, apart from the fact that all early ruminants had low crowned cheek teeth. Instead, recent years have seen the emergence evidence contradicting the conventional view that low tooth crowns always indicate leaf-eating and high tooth crowns grass-eating. Results Here we report the results of two independent palaeodietary reconstructions for one of the earliest deer, Procervulus ginsburgi from the Early Miocene of Spain, suggesting that despite having lower tooth crowns than any living ruminant, this species included a significant proportion of grass in its diet. Conclusion The phylogenetic distribution of feeding styles strongly supports that leaf-grass mixed feeding was the original feeding style of deer, and that later dietary specialization on leaves or grass occurred independently in several lineages. Evidence for other ruminant clades suggests that facultative mixed feeding may in fact have been the primitive dietary state of the Ruminantia, which would have been morphologically expressed only under specific environmental factors. PMID:18205907

  7. A Swift Look at SN 2011fe: The Earliest Ultraviolet Observations of a Type Ia Supernova

    NASA Technical Reports Server (NTRS)

    Oates, Samantha; Holland, Stephen; Immler, Stefan; Brown, Peter J.; Dawson, Kyle S.; DePasquale, Massimiliano; Gronwall, Caryl; Kuin, Paul; Mazzali, Paolo; Miline, Peter; Siegel, Michael

    2012-01-01

    We present the earliest ultraviolet (UV) observations of the bright Type Ia supernova SN 2011fe/PTF11kly in the nearby galaxy M101 at a distance of only 6.4 Mpc. It was discovered shortly after explosion by the Palomar Transient Factory and first observed by Swift/UVOT about a day after explosion. The early UV light is well-defined, with approx. 20 data points per filter in the 5 days after explosion. With these early UV observations, we extend the near-UV template of SNe Ia to earlier times for comparison with observations at low and high redshift and report fits from semiempirical models of the explosion. We find the early UV count rates to be well fit by the superposition of two parabolic curves. Finally, we use the early UV flux measurements to examine a possible shock interaction with a non-degenerate companion. We find that even a solar mass companion at a distance of a few solar radii is unlikely at more than 95% confidence.

  8. Basal tissue structure in the earliest euconodonts: Testing hypotheses of developmental plasticity in euconodont phylogeny

    USGS Publications Warehouse

    Dong, X.-P.; Donoghue, P.C.J.; Repetski, J.E.

    2005-01-01

    The hypothesis that conodonts are vertebrates rests solely on evidence of soft tissue anatomy. This has been corroborated by microstructural, topological and developmental evidence of homology between conodont and vertebrate hard tissues. However, these conclusions have been reached on the basis of evidence from highly derived euconodont taxa and the degree to which they are representative of plesiomorphic euconodonts remains an open question. Furthermore, the range of variation in tissue types comprising the euconodont basal body has been used to establish a hypothesis of developmental plasticity early in the phylogeny of the clade, and a model of diminishing potentiality in the evolution of development systems. The microstructural fabrics of the basal tissues of the earliest euconodonts (presumed to be the most plesiomorphic) are examined to test these two hypotheses. It is found that the range of microstructural variation observed hitherto was already apparent among plesiomorphic euconodonts. Thus, established histological data are representative of the most plesiomorphic euconodonts. However, although there is evidence of a range in microstructural fabrics, these are compatible with the dentine tissue system alone, and the degree of variation is compatible with that seen in clades of comparable diversity. ?? The Palaeontological Association.

  9. Albumin Binding Function: The Potential Earliest Indicator for Liver Function Damage

    PubMed Central

    Ge, Penglei; Yang, Huayu; Lu, Jingfen; Liao, Wenjun; Du, Shunda; Xu, Yingli; Xu, Haifeng; Lu, Xin; Sang, Xinting; Zhong, Shouxian; Huang, Jiefu

    2016-01-01

    Background. Currently there is no indicator that can evaluate actual liver lesion for early stages of viral hepatitis, nonalcoholic fatty liver disease (NAFLD), and cirrhosis. Aim of this study was to investigate if albumin binding function could better reflect liver function in these liver diseases. Methods. An observational study was performed on 193 patients with early NAFLD, viral hepatitis, and cirrhosis. Cirrhosis patients were separated according to Child-Pugh score into A, B, and C subgroup. Albumin metal ion binding capacity (Ischemia-modified albumin transformed, IMAT) and fatty acid binding capacity (total binding sites, TBS) were detected. Results. Both IMAT and TBS were significantly decreased in patients with NAFLD and early hepatitis. In hepatitis group, they declined prior to changes of liver enzymes. IMAT was significantly higher in cirrhosis Child-Pugh class A group than hepatitis patients and decreased in Child-Pugh class B and class C patients. Both IMAT/albumin and TBS/albumin decreased significantly in hepatitis and NAFLD group patients. Conclusions. This is the first study to discover changes of albumin metal ion and fatty acid binding capacities prior to conventional biomarkers for liver damage in early stage of liver diseases. They may become potential earliest sensitive indicators for liver function evaluation. PMID:28101103

  10. Earliest Carboniferous tetrapod and arthropod faunas from Scotland populate Romer's Gap

    PubMed Central

    Smithson, Timothy R.; Wood, Stanley P.; Marshall, John E. A.; Clack, Jennifer A.

    2012-01-01

    Devonian tetrapods (limbed vertebrates), known from an increasingly large number of localities, have been shown to be mainly aquatic with many primitive features. In contrast, the post-Devonian record is marked by an Early Mississippian temporal gap ranging from the earliest Carboniferous (Tournaisian and early Viséan) to the mid-Viséan. By the mid-Viséan, tetrapods had become effectively terrestrial as attested by the presence of stem amniotes, developed an essentially modern aspect, and given rise to the crown group. Up to now, only two localities have yielded tetrapod specimens from the Tournaisian stage: one in Scotland with a single articulated skeleton and one in Nova Scotia with isolated bones, many of uncertain identity. We announce a series of discoveries of Tournaisian-age localities in Scotland that have yielded a wealth of new tetrapod and arthropod fossils. These include both terrestrial and aquatic forms and new taxa. We conclude that the gap in the fossil record has been an artifact of collection failure. PMID:22393016

  11. Earliest date for milk use in the Near East and southeastern Europe linked to cattle herding.

    PubMed

    Evershed, Richard P; Payne, Sebastian; Sherratt, Andrew G; Copley, Mark S; Coolidge, Jennifer; Urem-Kotsu, Duska; Kotsakis, Kostas; Ozdoğan, Mehmet; Ozdoğan, Aslý E; Nieuwenhuyse, Olivier; Akkermans, Peter M M G; Bailey, Douglass; Andeescu, Radian-Romus; Campbell, Stuart; Farid, Shahina; Hodder, Ian; Yalman, Nurcan; Ozbaşaran, Mihriban; Biçakci, Erhan; Garfinkel, Yossef; Levy, Thomas; Burton, Margie M

    2008-09-25

    The domestication of cattle, sheep and goats had already taken place in the Near East by the eighth millennium bc. Although there would have been considerable economic and nutritional gains from using these animals for their milk and other products from living animals-that is, traction and wool-the first clear evidence for these appears much later, from the late fifth and fourth millennia bc. Hence, the timing and region in which milking was first practised remain unknown. Organic residues preserved in archaeological pottery have provided direct evidence for the use of milk in the fourth millennium in Britain, and in the sixth millennium in eastern Europe, based on the delta(13)C values of the major fatty acids of milk fat. Here we apply this approach to more than 2,200 pottery vessels from sites in the Near East and southeastern Europe dating from the fifth to the seventh millennia bc. We show that milk was in use by the seventh millennium; this is the earliest direct evidence to date. Milking was particularly important in northwestern Anatolia, pointing to regional differences linked with conditions more favourable to cattle compared to other regions, where sheep and goats were relatively common and milk use less important. The latter is supported by correlations between the fat type and animal bone evidence.

  12. The Earliest Stages of Star and Planet Formation: Core Collapse, and the Formation of Disks and Outflows

    NASA Astrophysics Data System (ADS)

    Li, Z.-Y.; Banerjee, R.; Pudritz, R. E.; Jørgensen, J. K.; Shang, H.; Krasnopolsky, R.; Maury, A.

    The formation of stars and planets are connected through disks. Our theoretical understanding of disk formation has undergone drastic changes in recent years, and we are on the brink of a revolution in disk observation enabled by the Atacama Large Millimeter Array (ALMA). Large rotationally supported circumstellar disks, although common around more evolved young stellar objects (YSOs), are rarely detected during the earliest, "class 0" phase; however, a few excellent candidates have been discovered recently around both low- and high-mass protostars. In this early phase, prominent outflows are ubiquitously observed; they are expected to be associated with at least small magnetized disks. Whether the paucity of large Keplerian disks is due to observational challenges or intrinsically different properties of the youngest disks is unclear. In this review, we focus on the observations and theory of the formation of early disks and outflows and their connections with the first phases of planet formation. Disk formation — once thought to be a simple consequence of the conservation of angular momentum during hydrodynamic core collapse — is far more subtle in magnetized gas. In this case, the rotation can be strongly magnetically braked. Indeed, both analytic arguments and numerical simulations have shown that disk formation is suppressed in the strict ideal magnetohydrodynamic (MHD) limit for the observed level of core magnetization. We review what is known about this "magnetic braking catastrophe," possible ways to resolve it, and the current status of early disk observations. Possible resolutions include non-ideal MHD effects (ambipolar diffusion, Ohmic dissipation, and the Hall effect), magnetic interchange instability in the inner part of protostellar accretion flow, turbulence, misalignment between the magnetic field and rotation axis, and depletion of the slowly rotating envelope by outflow stripping or accretion. Outflows are also intimately linked to disk

  13. Middle school students' understanding of the natural history of the Earth and life on Earth as a function of deep time

    NASA Astrophysics Data System (ADS)

    Pulling, Azalie Cecile

    The purpose of this study was to use deep time, that is geologic time as a mechanism to explore middle school students' understanding of the natural history of the earth and the evolution of life on earth. Geologic time is a logical precursor to middle school students' understanding of biological evolution. This exploratory, mixed model study used qualitative and quantitative methods in each stage of the research to explore sixth grade students, understanding of geologic time, their worldviews (e.g., conceptual ecology), and conceptual change. The study included fifty-nine students in the large group study and four case studies. The primary data collection instrument was the Geologic Timeline Survey. Additional data collection instruments and methods (e.g., concept evaluation statement, journal entries, word associations, interviews, and formal tests) were used to triangulate the study findings. These data were used to create narrative modal profiles of the categories of student thinking that emerged from the large group analysis: Middle School (MS) Scientists (correct science), MS Protoscientists (approaching correct science), MS Prescientists (dinosaur understanding), and MS Pseudoscientists (fundamental religious understanding). Case studies were used to provide a thick description of each category. This study discovered a pattern of student thinking about geologic time that moved along a knowledge continuum from pseudoscience (fundamental creationist understanding) to prescience (everyday-science understanding) to science (correct or approaching correct science). The researcher described the deep-seated misconceptions produced by the prescience thinking level, e.g., dinosaur misconceptions, and cautioned the science education community about using dinosaurs as a glamour-science topic. The most limiting conceptual frameworks found in this study were prescience (a dinosaur focus) and pseudoscience (a fundamental religious focus). An understanding of geologic time

  14. THE EARLIEST NEAR-INFRARED TIME-SERIES SPECTROSCOPY OF A TYPE Ia SUPERNOVA

    SciTech Connect

    Hsiao, E. Y.; Phillips, M. M.; Morrell, N.; Contreras, C.; Roth, M.; Marion, G. H.; Kirshner, R. P.; Burns, C. R.; Freedman, W. L.; Persson, S. E.; Winge, C.; Gerardy, C. L.; Hoeflich, P.; Im, M.; Jeon, Y.; Pignata, G.; Stanishev, V.; and others

    2013-04-01

    We present ten medium-resolution, high signal-to-noise ratio near-infrared (NIR) spectra of SN 2011fe from SpeX on the NASA Infrared Telescope Facility (IRTF) and Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North, obtained as part of the Carnegie Supernova Project. This data set constitutes the earliest time-series NIR spectroscopy of a Type Ia supernova (SN Ia), with the first spectrum obtained at 2.58 days past the explosion and covering -14.6 to +17.3 days relative to B-band maximum. C I {lambda}1.0693 {mu}m is detected in SN 2011fe with increasing strength up to maximum light. The delay in the onset of the NIR C I line demonstrates its potential to be an effective tracer of unprocessed material. For the first time in a SN Ia, the early rapid decline of the Mg II {lambda}1.0927 {mu}m velocity was observed, and the subsequent velocity is remarkably constant. The Mg II velocity during this constant phase locates the inner edge of carbon burning and probes the conditions under which the transition from deflagration to detonation occurs. We show that the Mg II velocity does not correlate with the optical light-curve decline rate {Delta}m{sub 15}(B). The prominent break at {approx}1.5 {mu}m is the main source of concern for NIR k-correction calculations. We demonstrate here that the feature has a uniform time evolution among SNe Ia, with the flux ratio across the break strongly correlated with {Delta}m{sub 15}(B). The predictability of the strength and the onset of this feature suggests that the associated k-correction uncertainties can be minimized with improved spectral templates.

  15. Protein structural and surface water rearrangement constitute major events in the earliest aggregation stages of tau

    PubMed Central

    Pavlova, Anna; Cheng, Chi-Yuan; Kinnebrew, Maia; Lew, John; Dahlquist, Frederick W.; Han, Songi

    2016-01-01

    Protein aggregation plays a critical role in the pathogenesis of neurodegenerative diseases, and the mechanism of its progression is poorly understood. Here, we examine the structural and dynamic characteristics of transiently evolving protein aggregates under ambient conditions by directly probing protein surface water diffusivity, local protein segment dynamics, and interprotein packing as a function of aggregation time, along the third repeat domain and C terminus of Δtau187 spanning residues 255–441 of the longest isoform of human tau. These measurements were achieved with a set of highly sensitive magnetic resonance tools that rely on site-specific electron spin labeling of Δtau187. Within minutes of initiated aggregation, the majority of Δtau187 that is initially homogeneously hydrated undergoes structural transformations to form partially structured aggregation intermediates. This is reflected in the dispersion of surface water dynamics that is distinct around the third repeat domain, found to be embedded in an intertau interface, from that of the solvent-exposed C terminus. Over the course of hours and in a rate-limiting process, a majority of these aggregation intermediates proceed to convert into stable β-sheet structured species and maintain their stacking order without exchanging their subunits. The population of β-sheet structured species is >5% within 5 min of aggregation and gradually grows to 50–70% within the early stages of fibril formation, while they mostly anneal block-wisely to form elongated fibrils. Our findings suggest that the formation of dynamic aggregation intermediates constitutes a major event occurring in the earliest stages of tau aggregation that precedes, and likely facilitates, fibril formation and growth. PMID:26712030

  16. Late Paleocene fossils from the Cerrejon Formation, Colombia, are the earliest record of Neotropical rainforest.

    PubMed

    Wing, Scott L; Herrera, Fabiany; Jaramillo, Carlos A; Gómez-Navarro, Carolina; Wilf, Peter; Labandeira, Conrad C

    2009-11-03

    Neotropical rainforests have a very poor fossil record, making hypotheses concerning their origins difficult to evaluate. Nevertheless, some of their most important characteristics can be preserved in the fossil record: high plant diversity, dominance by a distinctive combination of angiosperm families, a preponderance of plant species with large, smooth-margined leaves, and evidence for a high diversity of herbivorous insects. Here, we report on an approximately 58-my-old flora from the Cerrejón Formation of Colombia (paleolatitude approximately 5 degrees N) that is the earliest megafossil record of Neotropical rainforest. The flora has abundant, diverse palms and legumes and similar family composition to extant Neotropical rainforest. Three-quarters of the leaf types are large and entire-margined, indicating rainfall >2,500 mm/year and mean annual temperature >25 degrees C. Despite modern family composition and tropical paleoclimate, the diversity of fossil pollen and leaf samples is 60-80% that of comparable samples from extant and Quaternary Neotropical rainforest from similar climates. Insect feeding damage on Cerrejón fossil leaves, representing primary consumers, is abundant, but also of low diversity, and overwhelmingly made by generalist feeders rather than specialized herbivores. Cerrejón megafossils provide strong evidence that the same Neotropical rainforest families have characterized the biome since the Paleocene, maintaining their importance through climatic phases warmer and cooler than present. The low diversity of both plants and herbivorous insects in this Paleocene Neotropical rainforest may reflect an early stage in the diversification of the lineages that inhabit this biome, and/or a long recovery period from the terminal Cretaceous extinction.

  17. Stable Isotopes and Zooarchaeology at Teotihuacan, Mexico Reveal Earliest Evidence of Wild Carnivore Management in Mesoamerica.

    PubMed

    Sugiyama, Nawa; Somerville, Andrew D; Schoeninger, Margaret J

    2015-01-01

    From Roman gladiatorial combat to Egyptian animal mummies, the capture and manipulation of carnivores was instrumental in helping to shape social hierarchies throughout the ancient world. This paper investigates the historical inflection point when humans began to control animals not only as alimental resources but as ritual symbols and social actors in the New World. At Teotihuacan (A.D. 1-550), one of the largest pre-Hispanic cities, animal remains were integral components of ritual caches expressing state ideology and militarism during the construction of the Moon and the Sun Pyramids. The caches contain the remains of nearly 200 carnivorous animals, human sacrificial victims and other symbolic artifacts. This paper argues the presence of skeletal pathologies of infectious disease and injuries manifest on the carnivore remains show direct evidence of captivity. Stable isotope analysis (δ13C and δ15N) of bones and teeth confirms that some of these carnivores were consuming high levels of C4 foods, likely reflecting a maize-based anthropocentric food chain. These results push back the antiquity of keeping captive carnivores for ritualistic purposes nearly 1000 years before the Spanish conquistadors described Moctezuma's zoo at the Aztec capital. Mirroring these documents the results indicate a select group of carnivores at Teotihuacan may have been fed maize-eating omnivores, such as dogs and humans. Unlike historical records, the present study provides the earliest and direct archaeological evidence for this practice in Mesoamerica. It also represents the first systematic isotopic exploration of a population of archaeological eagles (n = 24) and felids (n = 29).

  18. Earliest evidence for cheese making in the sixth millennium BC in northern Europe.

    PubMed

    Salque, Mélanie; Bogucki, Peter I; Pyzel, Joanna; Sobkowiak-Tabaka, Iwona; Grygiel, Ryszard; Szmyt, Marzena; Evershed, Richard P

    2013-01-24

    The introduction of dairying was a critical step in early agriculture, with milk products being rapidly adopted as a major component of the diets of prehistoric farmers and pottery-using late hunter-gatherers. The processing of milk, particularly the production of cheese, would have been a critical development because it not only allowed the preservation of milk products in a non-perishable and transportable form, but also it made milk a more digestible commodity for early prehistoric farmers. The finding of abundant milk residues in pottery vessels from seventh millennium sites from north-western Anatolia provided the earliest evidence of milk processing, although the exact practice could not be explicitly defined. Notably, the discovery of potsherds pierced with small holes appear at early Neolithic sites in temperate Europe in the sixth millennium BC and have been interpreted typologically as 'cheese-strainers', although a direct association with milk processing has not yet been demonstrated. Organic residues preserved in pottery vessels have provided direct evidence for early milk use in the Neolithic period in the Near East and south-eastern Europe, north Africa, Denmark and the British Isles, based on the δ(13)C and Δ(13)C values of the major fatty acids in milk. Here we apply the same approach to investigate the function of sieves/strainer vessels, providing direct chemical evidence for their use in milk processing. The presence of abundant milk fat in these specialized vessels, comparable in form to modern cheese strainers, provides compelling evidence for the vessels having being used to separate fat-rich milk curds from the lactose-containing whey. This new evidence emphasizes the importance of pottery vessels in processing dairy products, particularly in the manufacture of reduced-lactose milk products among lactose-intolerant prehistoric farming communities.

  19. Origin and age of the earliest Martian crust from meteorite NWA 7533.

    PubMed

    Humayun, M; Nemchin, A; Zanda, B; Hewins, R H; Grange, M; Kennedy, A; Lorand, J-P; Göpel, C; Fieni, C; Pont, S; Deldicque, D

    2013-11-28

    The ancient cratered terrain of the southern highlands of Mars is thought to hold clues to the planet's early differentiation, but until now no meteoritic regolith breccias have been recovered from Mars. Here we show that the meteorite Northwest Africa (NWA) 7533 (paired with meteorite NWA 7034) is a polymict breccia consisting of a fine-grained interclast matrix containing clasts of igneous-textured rocks and fine-grained clast-laden impact melt rocks. High abundances of meteoritic siderophiles (for example nickel and iridium) found throughout the rock reach a level in the fine-grained portions equivalent to 5 per cent CI chondritic input, which is comparable to the highest levels found in lunar breccias. Furthermore, analyses of three leucocratic monzonite clasts show a correlation between nickel, iridium and magnesium consistent with differentiation from impact melts. Compositionally, all the fine-grained material is alkalic basalt, chemically identical (except for sulphur, chlorine and zinc) to soils from Gusev crater. Thus, we propose that NWA 7533 is a Martian regolith breccia. It contains zircons for which we measured an age of 4,428 ± 25 million years, which were later disturbed 1,712 ± 85 million years ago. This evidence for early crustal differentiation implies that the Martian crust, and its volatile inventory, formed in about the first 100 million years of Martian history, coeval with earliest crust formation on the Moon and the Earth. In addition, incompatible element abundances in clast-laden impact melt rocks and interclast matrix provide a geochemical estimate of the average thickness of the Martian crust (50 kilometres) comparable to that estimated geophysically.

  20. Discovery of the Earliest-Type Oe Stars in the Small Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Golden-Marx, J. B.; Oey, M. S.; Lamb, J. B.; Graus, A. S.

    2016-11-01

    No classical Oe/Be stars with spectral type earlier than O7.5e have been identified to date in the Milky Way (MW). This is consistent with the decretion disk model because strong stellar winds cause early-type O stars to lose angular momentum, thereby preventing them from rotating fast enough to spin out decretion disks. However, metal-poor O stars have weaker stellar winds, allowing the stars to retain angular momentum. Therefore, low-metallicity environments should promote the formation of Oe stars, including those of earlier spectral types than observed in high-metallicity environments. Using the RIOTS4 survey, a spatially complete spectroscopic survey of Small Magellanic Cloud (SMC) field OB stars taken with the IMACS multi-slit spectrograph at the Magellan Baade Telescope, we identify 25-31 SMC field Oe stars, which account for 20-28% of SMC field O stars. This fraction is significantly higher than in the MW, where < 10-15% of O stars display the Be phenomenon. We also present 5-7 Oe stars of spectral type ranging from O5.5e to O7e, all earlier spectral types than the earliest MW Oe star. These early type Oe stars represent 20-23% of our SMC Oe stars, a dramatic increase compared to the MW, where no Oe stars have been identified with these early spectral types. Thus, the higher frequencies of Oe stars and their earlier spectral range in the metal-poor SMC are consistent with the decretion disk model.

  1. Indigenous Arabs are descendants of the earliest split from ancient Eurasian populations

    PubMed Central

    Rodriguez-Flores, Juan L.; Fakhro, Khalid; Agosto-Perez, Francisco; Ramstetter, Monica D.; Arbiza, Leonardo; Vincent, Thomas L.; Robay, Amal; Malek, Joel A.; Suhre, Karsten; Chouchane, Lotfi; Badii, Ramin; Al-Nabet Al-Marri, Ajayeb; Abi Khalil, Charbel; Zirie, Mahmoud; Jayyousi, Amin; Salit, Jacqueline; Keinan, Alon; Clark, Andrew G.; Crystal, Ronald G.; Mezey, Jason G.

    2016-01-01

    An open question in the history of human migration is the identity of the earliest Eurasian populations that have left contemporary descendants. The Arabian Peninsula was the initial site of the out-of-Africa migrations that occurred between 125,000 and 60,000 yr ago, leading to the hypothesis that the first Eurasian populations were established on the Peninsula and that contemporary indigenous Arabs are direct descendants of these ancient peoples. To assess this hypothesis, we sequenced the entire genomes of 104 unrelated natives of the Arabian Peninsula at high coverage, including 56 of indigenous Arab ancestry. The indigenous Arab genomes defined a cluster distinct from other ancestral groups, and these genomes showed clear hallmarks of an ancient out-of-Africa bottleneck. Similar to other Middle Eastern populations, the indigenous Arabs had higher levels of Neanderthal admixture compared to Africans but had lower levels than Europeans and Asians. These levels of Neanderthal admixture are consistent with an early divergence of Arab ancestors after the out-of-Africa bottleneck but before the major Neanderthal admixture events in Europe and other regions of Eurasia. When compared to worldwide populations sampled in the 1000 Genomes Project, although the indigenous Arabs had a signal of admixture with Europeans, they clustered in a basal, outgroup position to all 1000 Genomes non-Africans when considering pairwise similarity across the entire genome. These results place indigenous Arabs as the most distant relatives of all other contemporary non-Africans and identify these people as direct descendants of the first Eurasian populations established by the out-of-Africa migrations. PMID:26728717

  2. Stable Isotopes and Zooarchaeology at Teotihuacan, Mexico Reveal Earliest Evidence of Wild Carnivore Management in Mesoamerica

    PubMed Central

    Sugiyama, Nawa; Somerville, Andrew D.; Schoeninger, Margaret J.

    2015-01-01

    From Roman gladiatorial combat to Egyptian animal mummies, the capture and manipulation of carnivores was instrumental in helping to shape social hierarchies throughout the ancient world. This paper investigates the historical inflection point when humans began to control animals not only as alimental resources but as ritual symbols and social actors in the New World. At Teotihuacan (A.D. 1–550), one of the largest pre-Hispanic cities, animal remains were integral components of ritual caches expressing state ideology and militarism during the construction of the Moon and the Sun Pyramids. The caches contain the remains of nearly 200 carnivorous animals, human sacrificial victims and other symbolic artifacts. This paper argues the presence of skeletal pathologies of infectious disease and injuries manifest on the carnivore remains show direct evidence of captivity. Stable isotope analysis (δ13C and δ15N) of bones and teeth confirms that some of these carnivores were consuming high levels of C4 foods, likely reflecting a maize-based anthropocentric food chain. These results push back the antiquity of keeping captive carnivores for ritualistic purposes nearly 1000 years before the Spanish conquistadors described Moctezuma’s zoo at the Aztec capital. Mirroring these documents the results indicate a select group of carnivores at Teotihuacan may have been fed maize-eating omnivores, such as dogs and humans. Unlike historical records, the present study provides the earliest and direct archaeological evidence for this practice in Mesoamerica. It also represents the first systematic isotopic exploration of a population of archaeological eagles (n = 24) and felids (n = 29). PMID:26332042

  3. The Earliest Near-infrared Time-series Spectroscopy of a Type Ia Supernova

    NASA Astrophysics Data System (ADS)

    Hsiao, E. Y.; Marion, G. H.; Phillips, M. M.; Burns, C. R.; Winge, C.; Morrell, N.; Contreras, C.; Freedman, W. L.; Kromer, M.; Gall, E. E. E.; Gerardy, C. L.; Höflich, P.; Im, M.; Jeon, Y.; Kirshner, R. P.; Nugent, P. E.; Persson, S. E.; Pignata, G.; Roth, M.; Stanishev, V.; Stritzinger, M.; Suntzeff, N. B.

    2013-04-01

    We present ten medium-resolution, high signal-to-noise ratio near-infrared (NIR) spectra of SN 2011fe from SpeX on the NASA Infrared Telescope Facility (IRTF) and Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North, obtained as part of the Carnegie Supernova Project. This data set constitutes the earliest time-series NIR spectroscopy of a Type Ia supernova (SN Ia), with the first spectrum obtained at 2.58 days past the explosion and covering -14.6 to +17.3 days relative to B-band maximum. C I λ1.0693 μm is detected in SN 2011fe with increasing strength up to maximum light. The delay in the onset of the NIR C I line demonstrates its potential to be an effective tracer of unprocessed material. For the first time in a SN Ia, the early rapid decline of the Mg II λ1.0927 μm velocity was observed, and the subsequent velocity is remarkably constant. The Mg II velocity during this constant phase locates the inner edge of carbon burning and probes the conditions under which the transition from deflagration to detonation occurs. We show that the Mg II velocity does not correlate with the optical light-curve decline rate Δm 15(B). The prominent break at ~1.5 μm is the main source of concern for NIR k-correction calculations. We demonstrate here that the feature has a uniform time evolution among SNe Ia, with the flux ratio across the break strongly correlated with Δm 15(B). The predictability of the strength and the onset of this feature suggests that the associated k-correction uncertainties can be minimized with improved spectral templates.

  4. Planets and Life

    NASA Astrophysics Data System (ADS)

    Sullivan, Woodruff T., III; Baross, John

    2007-09-01

    Foreword; Preface; Contributors; Prologue; Part I. History: 1. History of astrobiological ideas W. T. Sullivan and D. Carney; 2. From exobiology to astrobiology S. J. Dick; Part II. The Physical Stage: 3. Formation of Earth-like habitable planets D. E. Brownlee and M. Kress; 4. Planetary atmospheres and life D. Catling and J. F. Kasting; Part III. The Origin of Life on Earth: 5. Does 'life' have a definition? C.E. Cleland and C. F. Chyba; 6. Origin of life: crucial issues R. Shapiro; 7. Origin of proteins and nucleic acids A. Ricardo and S. A. Benner; 8. The roots of metabolism G.D. Cody and J. H. Scott; 9. Origin of cellular life D. W. Deamer; Part IV. Life on Earth: 10. Evolution: a defining feature of life J. A. Baross; 11. Evolution of metabolism and early microbial communities J. A. Leigh, D. A. Stahl and J. T. Staley; 12. The earliest records of life on Earth R. Buick; 13. The origin and diversification of eukaryotes M. L. Sogin, D. J. Patterson and A. McArthur; 14. Limits of carbon life on Earth and elsewhere J. A. Baross, J. Huber and M. Schrenk; 15. Life in ice J. W. Deming and H. Eicken; 16. The evolution and diversification of life S. Awramik and K. J. McNamara; 17. Mass extinctions P. D. Ward; Part V. Potentially Habitable Worlds: 18. Mars B. M. Jakosky, F. Westall and A. Brack; 19. Europa C. F. Chyba and C. B. Phillips; 20. Titan J. I. Lunine and B. Rizk; 21. Extrasolar planets P. Butler; Part VI. Searching for Extraterrestrial Life: 22. How to search for life on other worlds C. P. McKay; 23. Instruments and strategies for detecting extraterrestrial life P. G. Conrad; 24. Societial and ethical concerns M. S. Race; 25. Planetary protection J. D. Rummel; 26. Searching for extraterrestrial intelligence J. C. Tarter; 27. Alien biochemistries P. D. Ward and S. A. Benner; Part VII. Future of the Field: 28. Disciplinary and educational opportunities L. Wells, J. Armstrong and J. Huber; Epilogue C. F. Chyba; Appendixes: A. Units and usages; B. Planetary

  5. Water and Life on Mars

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  6. Yawning throughout life.

    PubMed

    Giganti, F; Salzarulo, P

    2010-01-01

    Yawning is a behavior that begins in the first stages of life. It has not only been observed in infants and in newborns, but also in fetuses of 12-14 weeks' gestational age. Yawning frequency changes over the life span. In preterm infants, the number of yawns decreases between 31 and 40 weeks' postconceptional age, mainly during the day. In this period of life, yawning is an isolated behavior rarely occurring in bursts, and its frequency is quite low with respect to adults. The incidence of yawning seems to increase when children attend elementary school, whereas this is reduced in the elderly. Aged people yawn less than younger ones, mainly during morning and mid-afternoon. In adults, the time course of yawning is associated with the time course of sleepiness, except upon awakening when the high frequency of yawns is not associated with high sleepiness. In adults, yawning frequency increases in the early morning and in the late evening, whereas at the earliest stages of development (fetuses and preterm infants) yawning does not show diurnal variations. Yawning seems to be involved in the modulation of arousal process across the whole life span. In preterm infants, yawning is often followed by motor activation and it is more common during waking than sleep; in adults, yawning occurs mainly at sleep onset and upon awakening.

  7. The earliest drawings of datable auroras and a two-tail comet from the Syriac Chronicle of Zūqnīn

    NASA Astrophysics Data System (ADS)

    Hayakawa, Hisashi; Mitsuma, Yasuyuki; Fujiwara, Yasunori; Kawamura, Akito Davis; Kataoka, Ryuho; Ebihara, Yusuke; Kosaka, Shunsuke; Iwahashi, Kiyomi; Tamazawa, Harufumi; Isobe, Hiroaki

    2017-01-01

    People have probably been watching the sky since the beginning of human history. Observers in pre-telescopic ages recorded anomalous events, which now provide uniquely valuable information for modern scientists. Records that include drawings are particularly useful, since the verbal expressions recorded by pre-telescopic observers, who did not know the physical nature of the phenomena, are often ambiguous. However, drawings concerning specific datable events in the historical documents are far fewer than the verbal records. Therefore, in this paper we show the possible earliest drawings of datable auroras and a two-tail comet included in a manuscript of the Chronicle of Zūqnīn, a Syriac chronicle up to 775/776 CE, to interpret their nature. Careful perusing the original Syriac autograph manuscript, MS Vat.Sir.162, provide not only historical facts in the realm around Amida, but also information concerning low-latitude aurora observations due to extreme space weather events and the existence of sun-grazing comets.

  8. Man-Made Closed Ecological Systems as Model of Natural Ecosystems and as Means to Provide High Quality of Human Life in Adverse Environment

    NASA Technical Reports Server (NTRS)

    Gitelson, I. I.; Harper, Lynn (Technical Monitor)

    1994-01-01

    For its more than thirty year long history, the experimental creation of closed ecological systems has from its very sources been distinctly and strongly motivated by the development of human life-support systems for space. As the trend developed its fundamental significance and broad opportunities of terrestrial applications of the technologies under development were coming to the foreground. Nowadays, it can be argued that development of closed ecosystems is experimental foundation of a new branch of ecology biospherics, the goal of which is to comprehend the regularities of existence of the biosphere as a unique in the Universe (in that part of it that we know, at least) closed ecosystem. Closed technologies can be implemented in life-support systems under adverse conditions of life on the Earth - in Arctic and Antarctic latitudes, deserts, high mountains or deep in the ocean, as well as under the conditions of polluted water and air. In space where the environment is hostile for life all around the cell of life should be sealed and the life-support system as close to the ideally closed cyclic turnover of the matter as possible. Under terrestrial conditions designers should strive for maximum closure of the limiting factor: water - in deserts, oxygen - in high mountains, energy - in polar latitudes, etc. Essential closure of a life-support systems withstands also pollution of the environment by the wastes of human vital activity. This is of particular importance for the quarantine of visited planets, and on the Earth under the conditions of deficient heat in high latitudes and water in and areas. The report describes experimental ecosystem 'BIOS' and exohabitats being designed on its basis, which are adapted to various conditions, described capacities of the Center for Closed Ecosystems in Drasnoyarsk for international collaboration in research and education in this field.

  9. Mineral Bionization - Surface Chemical Modeling of the Emergence of Life

    NASA Astrophysics Data System (ADS)

    Arrhenius, G.

    2001-12-01

    The earliest stages in entering an RNA-world require natural mechanisms that are capable of selective concentration of simple aldehydes from dilute solution in the environment (4), furthermore phosphorylation of the sequestered aldehydes (2) and their catalytic condensation to form, selectively, tetrose- (threose) or pentose- (ribose) phosphate (3); the latter representing the R in RNA. A variety of common positively charged sheet structure minerals (mixed valence double layer metal hydroxide minerals such as hydrotalcite and green rust) have proven to be remarkably capable of performing these crucial tasks under simplified natural conditions (1). These prebiotic model reactions have demonstrated plausible closure of the gap, previously thought to preclude the natural formation of nucleoside phosphates, the backbone components of the information carrying genetic material. Pioneering research by other workers (5) has demonstrated the feasibility of necessary further steps in the chain toward functional RNA; mineral (montmorillonite) catalyzed oligomerization of nucleotides, the formation of complementary RNA strands (6) and the enzymatic activity of RNA (ribozymes). These contributions have placed the initially conjectural concept of an initial RNA-world on an experimental footing. Remaining problems include the initial transfer of information to spontaneously forming RNA, sufficient to convey biofunctionallity (7). Also in this central problem mineral surface interactions may be speculated to play a natural role; a question that is open to experimental verification. References. 1. Pitsch, S.; Eschenmoser, A.; Gedulin, B.; Hui, S. and Arrhenius, G. Origins Life Evol. Biosphere, 1994, 24 (5), 389. 2. Kolb, V.; Zhang, S.; Xu, Y.; Arrhenius, G. Origins Life Evol. Biosphere, 1997, 27, 485. 3. Krishnamurthy, R.; Pitsch, S.; Arrhenius, G. Origins Life Evol. Biosphere, Origins Life Evol. Biosphere 1999, 29, 139 4. Pitsch, S.; Krishnamurthy, R.; Arrhenius, G. Helv. Chim

  10. Auxosporulation in Paralia guyana MacGillivary (Bacillariophyta) and Possible New Insights into the Habit of the Earliest Diatoms

    PubMed Central

    Kaczmarska, Irena; Ehrman, James M.

    2015-01-01

    Background Diatoms are one of the most ecologically important aquatic micro-eukaryotes. As a group unambiguously recognized as diatoms, they seem to have appeared relatively recently with a limited record of putative remains from oldest sediments. In contrast, molecular clock estimates for the earliest possible emergence of diatoms suggest a considerably older date. Depending on the analysis, Paralia and Leptocylindrus have been recovered within the basal molecular divergences of diatoms. Thus these genera may be in the position to inform on characters that the earliest diatoms possessed. Findings Here we present auxospore development and structure of initial and post-auxospore cells in a representative of the ancient non-polar centric genus Paralia. Their initial frustules showed unusual, but not unprecedented, spore-like morphology. Similarly, initial frustules of Leptocylindrus have been long considered resting spores and a unique peculiarity of this genus. However, even though spore-like in appearance, initial cells of Paralia readily resumed mitotic divisions. In addition, Paralia post-auxospore cells underwent several rounds of mitoses in a multi-step process of building a typical, “perfect” vegetative valve. This degree of heteromorphy immediately post-auxosporulation is thus far unknown among the diatoms. Implications A spore-related origin of diatoms has already been considered, most recently in the form of the “multiplate diploid cyst” hypothesis. Our discovery that the initial cells in some of the most ancient diatom lineages are structurally spore-like is consistent with that hypothesis because the earliest diatoms may be expected to look somewhat similar to their ancestors. We speculate that because the earliest diatoms may have appeared less diatom-like and more spore-like, they could have gone unrecognized as such in the Triassic/Jurassic sediments. If correct, diatoms may indeed be much older than the fossil record indicates, and possibly

  11. Earliest description by Johann Friedrich Meckel, Senior (1750) of what is known today as Lutembacher syndrome (1916).

    PubMed

    Wiedemann, H R

    1994-10-15

    The letter that the famous anatomist Johann Friedrich Meckel, Sr. sent from Berlin on May 5, 1750 to the great Albrecht von Haller (at that time resident in Göttingen) contains the earliest reference to an unusual observation made by the former. Even today this observation is considered in the clinical literature to be the first description of a coarctation of the aorta. In fact, it is probably the first description of what is known today as Lutembacher syndrome.

  12. Repeated diffusion MRI reveals earliest time point for stratification of radiotherapy response in brain metastases

    NASA Astrophysics Data System (ADS)

    Mahmood, Faisal; Johannesen, Helle H.; Geertsen, Poul; Hansen, Rasmus H.

    2017-04-01

    An imaging biomarker for early prediction of treatment response potentially provides a non-invasive tool for better prognostics and individualized management of the disease. Radiotherapy (RT) response is generally related to changes in gross tumor volume manifesting months later. In this prospective study we investigated the apparent diffusion coefficient (ADC), perfusion fraction and pseudo diffusion coefficient derived from diffusion weighted MRI as potential early biomarkers for radiotherapy response of brain metastases. It was a particular aim to assess the optimal time point for acquiring the DW-MRI scan during the course of treatment, since to our knowledge this important question has not been addressed directly in previous studies. Twenty-nine metastases (N  =  29) from twenty-one patients, treated with whole-brain fractionated external beam RT were analyzed. Patients were scanned with a 1 T MRI system to acquire DW-, T2*W-, T2W- and T1W scans, before start of RT, at each fraction and at follow up two to three months after RT. The DW-MRI parameters were derived using regions of interest based on high b-value images (b  =  800 s mm‑2). Both volumetric and RECIST criteria were applied for response evaluation. It was found that in non-responding metastases the mean ADC decreased and in responding metastases it increased. The volume based response proved to be far more consistently predictable by the ADC change found at fraction number 7 and later, compared to the linear response (RECIST). The perfusion fraction and pseudo diffusion coefficient did not show sufficient prognostic value with either response assessment criteria. In conclusion this study shows that the ADC derived using high b-values may be a reliable biomarker for early assessment of radiotherapy response for brain metastases patients. The earliest response stratification can be achieved using two DW-MRI scans, one pre-treatment and one at treatment day 7–9 (equivalent to 21

  13. Earliest evidence of personal ornaments associated with burial: the Conus shells from Border Cave.

    PubMed

    d'Errico, Francesco; Backwell, Lucinda

    2016-04-01

    The four to six month old infant from Border Cave, found with a perforated Conus shell in a pit excavated in Howiesons Poort (HP) layers dated to 74 ± 4 BP, is considered the oldest instance of modern human burial from Africa, and the earliest example of a deceased human interred with a personal ornament. In this article we present new data retrieved from unpublished archives on the burial excavation, and conduct an in-depth analysis of the Conus found with the infant, and a second similar Conus that probably originates from the same layer. Based on morphological, morphometric and ecological evidence we assign these two shells to Conus ebraeus Linnaeus 1758, a tropical species still living on the nearest coastline to Border Cave, in northern KwaZulu-Natal. This attribution changes the paleoclimatic setting inferred from the previous ascription of these shells to Conus bairstowi, a species endemic to the Eastern Cape and adapted to colder sea surface temperatures. Reconstructions of 74 ka sea surface temperatures along the southern African east coast are consistent with our reassignment. Analysis of shell thanatocoenoses and biocoenosis from the KwaZulu-Natal coast, including microscopic study of their surfaces, reveals that complete, well preserved living or dead Conus, such as those found at Border Cave, are rare on beaches, can be collected at low tide at a depth of c. 0.5-2 m among the rocks, and that the archeological shells were dead when collected. We demonstrate that the perforations at the apex were produced by humans, and that traces of wear due to prolonged utilization as an ornament are present. SEM-EDX analysis of patches of red residue on the Conus found in the pit with the infant indicates that it is composed of iron, phosphorus, silicon, aluminium, and magnesium. Results indicate that, at least in some areas of southern Africa, the use of marine gastropods as ornaments, already attested in Still Bay, extended to the first phases of the HP.

  14. High-resolution stable carbon isotope record of the Permian to earliest Triassic from East Greenland

    NASA Astrophysics Data System (ADS)

    Sanson Barrera, Anna; Hochuli, Peter A.; Bucher, Hugo; Meier, Maximiliano; Schneebeli Hermann, Elke; Weissert, Helmut; Bernasconi, Stefano M.

    2013-04-01

    The Late Permian and Early Triassic organic carbon isotope records show global major excursions probably triggered by episodic volcanic degasing of the Siberian Large Igneous Province. Important and rapid fluctuations of the global carbon cycle are also reflected in the biosphere. The geological record seems to comprise several major floral and marine faunal turnovers indicating short-lived biotic recoveries. In northwest Pangea, the active Early Triassic Greenland - Norway rifting system led to the accommodation of thick sedimentary sequences. This basin has a great potential for detailed studies of regional and global biotic and climatic changes with high temporal resolution during this critical interval in Earth's history. The western part of this basin is exposed in north-eastern Greenland and is represented by a succession of deltaic sediments organized in a general regressive trend ranging throughout the Griesbachian and the onset of the Dienerian. On the eastern side of the basin the succession has been drilled off the Norwegian coast. On Hold with Hope (East Greenland, 74°N) up to ca. 800m thick sections of the ammonoid-bearing Early Triassic Wordie Creek Formation have been logged and sampled. Here we present a high-resolution organic carbon isotope record and preliminary palynofacies data of a 500m thick composite section ranging from the Permian into the earliest Triassic. The organic carbon isotope record is closely comparable to the coeval section from the Trøndelag platform in Mid-Norway. The two records show a first major negative shift (ca. -6‰) representing the unconformity between the Ravnefjeld and the Wordie Creek formations, regionally known as the lithological Permian-Triassic boundary. Higher up, a second negative shift of ca. -4‰ correlates with the carbon shift associated with the GSSP Permian-Triassic boundary as defined at Meishan (China), represented by carbon isotope values around -30‰. This negative shift is followed by a

  15. Employing an Osmium Clock to Investigate Earliest Paleogene Impact Recovery in the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Zaiss, J. M.; Ravizza, G. E.; Schmitz, B.

    2012-12-01

    Constraining the time scale of biotic recovery in the aftermath of mass extinctions is difficult because the normal patterns of cyclic sedimentation used to constrain sediment accumulation rates can be disrupted by the extinction event itself. At the Cretaceous-Paleogene (K-Pg) boundary, impact-induced changes in ocean chemistry provide a novel approach to time keeping for the earliest Paleogene pelagic sediments. The bolide impact, widely accepted as the primary cause of the K-Pg mass extinction, caused an abrupt decrease in the global seawater 187Os/188Os ratio from ~0.4 to < 0.2. Here, we employ a recently proposed geochemical "clock" which utilizes the change in the 187Os/188Os ratio of the sediment over time from low, post-impact ratios, immediately after the K-Pg event, back to the pre-impact, steady state ratios, to determine the amount of time elapsed since the impact event (Ravizza and VonderHaar, Paleoceanography, doi:10.1029/2012PA002301). This method assumes that the residence time of Os in the early Paleogene ocean is the same as in the modern ocean, making the Os clock most useful for constraining the age of sediments deposited in the first 200 kyr after the K-Pg mass extinction. While the model yields ages that compare favorably with the orbital tuning results from ODP Site 1262 on Walvis Ridge (South Atlantic), results from ODP Hole 738C located in the Indian Ocean sector of the Southern Ocean are surprising. In the first 50 cm of the Paleogene, Os data indicate a sedimentation rate of approximately 1 cm/kyr, at least 5 times faster than previously inferred from biostratigraphic data. From 50 cm to 250cm above the K-Pg, 187Os/188Os ratios increase gradually from 0.25 to ~0.3, yielding sediment accumulation rate estimates as high as 10 cm/kyr. If correct, these results require an episode of extremely rapid carbonate accumulation roughly 50 kyr after the extinction event. Alternatively, the Os isotope record may be biased by either reworked ejecta

  16. Recent structural and geochronological data on central Madagascar: in search of the earliest Panafrican events

    NASA Astrophysics Data System (ADS)

    Nédélec, A.; Paquette, J. L.; Ralison, B.; Bouchez, J. L.; Grégoire, V.

    2003-04-01

    The basement of central Madagascar registered a polyphase history during Panafrican times. The latest events (560--530 Ma) are responsible for a major N-S shear zone, the Angavo shear zone, characterized by steep foliation planes and N-S subhorizontal lineations (Nédélec et al., 2000). This shear zone has been active in low-pressure granulitic conditions and favoured the emplacement of shoshonitic magmas (e.g. Carion pluton). Due to its length and width (respectively 600 and 20 km), it is likely a structure of lithospheric significance. It is due to intracratonic reworking related to the final stages of Gondwana amalgamation. To the east, Collins &Windley (2002) suggest the existence of a suture (Betsimisaraka suture) along the Archaean Antongil block. However, the age of this suture and the existence of oceanic remnants are still to be unraveled, a point of major importance in the understanding of the Panafrcian collision. To the west, differents units have been recognized. The Itremo Series is the uppermost unit. As such, it is less metamorphosed and keeps evidence of early events. It is made of supracrustal rocks, the so-called SQC (schist-quartzite-carbonate) series, typical of a passive margin sequence. Microstructures and quartz c-axis fabrics in the quartzites bear evidence of an east-directed ductile shearing event (Nédélec et al., 2003), whose age is still unknown. Gneisses and migmatites underlying the Itremo sheet belong to the Graphite System, which also contain abundant intrusives. Calk-alkaline orthogneisses about 780 Ma are regarded as former arc magmas predating the Panafrican collision (Handke et al., 1999). Alkaline "stratoid" (sill-like) granites and syenites were dated at 630 Ma by Paquette &Nédélec (1998). A new U-Pb zircon age of 717 Ma from a Midongy-type (pink, fine-grained, biotite-bearing, mildly peraluminous) stratoid granite, west of the Itremo series, may represent the earliest event due to the Panafrican orogeny in Madagascar

  17. Bunbury Basalt: Gondwana breakup products or earliest vestiges of the Kerguelen mantle plume?

    NASA Astrophysics Data System (ADS)

    Olierook, Hugo K. H.; Jourdan, Fred; Merle, Renaud E.; Timms, Nicholas E.; Kusznir, Nick; Muhling, Janet R.

    2016-04-01

    In this contribution, we investigate the role of a mantle plume in the genesis of the Bunbury Basalt using high-precision 40Ar/39Ar geochronology and whole-rock geochemistry, and by using crustal basement thickness of the eastern Indian Ocean and the western Australian continent. The Bunbury Basalt is a series of lava flows and deep intrusive rocks in southwestern Australia thought to be the earliest igneous products from the proto-Kerguelen mantle plume. Nine new plateau ages indicate that the Bunbury Basalt erupted in three distinct phases, at 136.96 ± 0.43 Ma, 132.71 ± 0.43 Ma and 130.45 ± 0.82 Ma. All Bunbury Basalt samples are enriched tholeiitic basalts with varying contributions from the continental lithosphere that are similar to other Kerguelen plume-products. Based on plate reconstructions and the present geochronological constraints, the eruption of the oldest Bunbury Basalt preceded the emplacement of the Kerguelen large igneous province by at least 10-20 m.y. Such age differences between a precursor and the main magmatic event are not uncommon but do require additional explanation. Low crustal stretching factors beneath the Bunbury Basalt (β ≈ 1.4) indicate that decompression melting could not have been generated from asthenospheric mantle with a normal chemistry and geotherm. An elevated geotherm from the mantle plume coupled with the geochemical similarity between the Bunbury Basalt and other Kerguelen plume-products suggests a shared origin exists. However, new age constraints of the oldest Bunbury Basalt are synchronous with the breakup of eastern Gondwana and the initial opening of the Indian Ocean at ca. 137-136 Ma, which may mean an alternative explanation is possible. The enriched geochemistry can equally be explained by a patch of shallow mantle beneath the southern Perth Basin. The patch may have been enriched during Gondwana suturing at ca. 550-500 Ma, during early rifting events by magmatic underplating or by intruded melts into the

  18. Contribution of the earliest woody trees (lignophytes) to the greening of the continents

    NASA Astrophysics Data System (ADS)

    Meyer-Berthaud, B.; Decombeix, A.-L.

    2009-04-01

    The diversification of early terrestrial plants is characterized by an intense phase of morphological innovation during the Devonian that resulted in the evolution of a large variety of growth forms. Several unrelated taxa adopted the tree habit, a form characterized by its extended lifetime and the possession of a tall, vertical trunk.This evolution provided large-sized plants with functional advantages over smaller ones in terms of reproduction and light interception. From a biophysical point of view, this increase in stature was a challenge as it created new constraints in terms of biomechanical support and water transport. The various groups that evolved trees resolved these problems by adopting specific strategies in relation to their own evolutionary history and inherited traits. It is uncertain whether the evolution of the tree habit and of forests has directly promoted the diversification of the reproductive systems and the advent of the seed habit. But it created new niches, contributing to the diversication of the terrestrial floras and faunas. It may also have considerably impacted the biosphere and contributed to the dramatic decline of atmospheric CO2 in the Late Devonian through the enhanced development of soils and changes in erosional and sedimentary processes. Understanding these interactions through a better assessment of the structure, development, functioning and evolution of early trees represents a new challenge for paleobotanists. Here we provide a review of the earliest arborescent representatives of the lignophyte clade, paying special attention to the anatomical, morphological and developmental traits that may have contributed to their wide paleogeographical distribution in the Late Devonian and later on. These trees are the first ones in the history of vegetation to possess leaves as well as long-lived roots and branches. Their growth is three-dimensional by comparison to the essentially vertical growth of earlier trees. Using the

  19. Searching for the Youngest Protostellar Disks and Earliest Signs of Planet Formation

    NASA Astrophysics Data System (ADS)

    Segura-Cox, Dominique

    2017-01-01

    Circumstellar disks are fundamental for accretion and angular momentum distribution during the early phases of star formation. Class 0 objects are the youngest protostars and most embedded in their natal envelopes, and circumstellar disks can form even at this earliest stage of star formation. Less-embedded Class I protostars have cleared part of their surrounding envelope, yet the envelopes enshrouding Class 0 and Class I protostars have made detection of young protostellar disks difficult. Before this work, only 4 Class 0 and 10 Class I Keplerian disks were known. Through observational work with the VLA and ALMA on disks around some of the youngest protostars, my dissertation addresses two key questions regarding circumstellar disks and initial conditions for planet formation.1) How common are large Class 0 and I protostellar disks and what are their properties?We analyze dust continuum emission data toward all (~90) Class 0 and I sources in the Perseus molecular cloud from the 8 mm VLA Nascent Disk and Multiplicity (VANDAM) survey with 12 AU resolution. Because we lack kinematic data on small scales to confirm any resolved, elongated structures as rotationally supported, we fit the deprojected, averaged, and binned data in the u,v-plane to a disk-shaped profile to determine which sources are disk candidates.2) How early can disk substructures, and hence signs of early planet formation, be found in young disks?We study the ALMA 1.3 mm continuum observations of the disk of Class I source IRS 63 with 8 AU resolution to search for gaps in a young protostellar disk. Previous studies of disk substructure have revealed gaps in the disks of more evolved Class II sources, such as the famous HL Tau. If rings and gaps are observed in IRS 63, then planet formation and the associated disk sculpting must have started early in the Class I phase or before. If gaps are absent, then planets must have begun to form during the (late) Class I phase, rather than during the deeply

  20. Late Permian-earliest Triassic high-resolution organic carbon isotope and palynofacies records from Kap Stosch (East Greenland)

    NASA Astrophysics Data System (ADS)

    Sanson-Barrera, Anna; Hochuli, Peter A.; Bucher, Hugo; Schneebeli-Hermann, Elke; Weissert, Helmut; Adatte, Thierry; Bernasconi, Stefano M.

    2015-10-01

    During and after the end Permian mass extinction terrestrial and marine biota underwent major changes and reorganizations. The latest Permian and earliest Triassic is also characterized by major negative carbon isotope shifts reflecting fundamental changes in the carbon cycle. The present study documents a high-resolution bulk organic carbon isotope record and palynofacies analysis spanning the latest Permian-earliest Triassic of East Greenland. An almost 700 meter thick composite section from Kap Stosch allowed discriminating 6 chemostratigraphic intervals that provide the basis for the correlation with other coeval records across the world, and for the recognition of basin wide transgressive-regressive events documenting tectonic activity during the opening of the Greenland-Norway Basin. The identification of the main factors that influenced the organic carbon isotope signal during the earliest Triassic (Griesbachian to Dienerian) was possible due to the combination of bulk organic carbon isotope, palynofacies and Rock-Eval data. Two negative carbon isotopic shifts in the Kap Stosch record can be correlated with negative shifts recorded in coeval sections across the globe. A first negative shift precedes the base of the Triassic as defined by the first occurrence of the conodont Hindeodus parvus in the Meishan reference section, and the second one coincides with the suggested Griesbachian-Dienerian boundary. This new organic carbon isotope record from the extended Kap Stosch section from the Boreal Realm documents regional and global carbon cycle signals of the interval between the latest Palaeozoic and the onset of the Mesozoic.

  1. Trophic links, nutrient fluxes, and natural history in the Allium ursinum food web, with particular reference to life history traits of two hoverfly herbivores (Diptera: Syrphidae).

    PubMed

    Hövemeyer, Klaus

    1995-04-01

    The food web centering on Allium ursinum (Liliaceae) in a beech forest (Germany) is described, and temporal variation of active trophic links is related to species' life cycles. The most important insect herbivores are Cheilosia fasciata (a larval leaf miner) and Portevinia maculata (a larva bulb miner) (Diptera: Syrphidae). Energy, carbon and nitrogen flow in the food chain (Allium-Cheilosia-Phygadeuon ursini) are investigated and analysed with respect to differences in resource allocation by the leaf miner and its hymenoptereous parasitoid. In C. fasciata nitrogen is likely to be the limiting resource, while growth in Phygadeuon ursini appears energy-limited. Larval feeding habits of C. fasciata and Portevinia maculata determined the timing of the species' life cycles and, as a consequence, appeared to preclude the existence of a pupal parasitoid in Portevinia maculata. Further details of life history traits are demonstrated and discussed.

  2. How Much Could We Improve Children's Life Chances by Intervening Early and Often? CCF Brief #54

    ERIC Educational Resources Information Center

    Sawhill, Isabel V.; Karpilow, Quentin

    2014-01-01

    Children born into low-income families face barriers to success in each stage of life from birth to age 40. Using data on a representative group of American children and a life cycle model to track their progress from the earliest years through school and beyond, the authors show that well-evaluated targeted interventions can close over 70 percent…

  3. Social-Emotional Development, Families, and Mental Health Needs in the Earliest Years

    ERIC Educational Resources Information Center

    Ensher, Gail L.; Clark, David A.

    2016-01-01

    Most of the time, infants start life with all of the bioneurological- sensory resources and social/emotional readiness to begin their journey toward learning how to relate to their closest family members and, eventually, people in their wider world. Attachment, bonding, security, and an emotional home with significant, consistent caregivers are…

  4. Earth's earliest biosphere-a proposal to develop a collection of curated archean geologic reference materials

    NASA Technical Reports Server (NTRS)

    Lindsay, John F.; McKay, David S.; Allen, Carlton C.

    2003-01-01

    The discovery of evidence indicative of life in a Martian meteorite has led to an increase in interest in astrobiology. As a result of this discovery, and the ensuing controversy, it has become apparent that our knowledge of the early development of life on Earth is limited. Archean stratigraphic successions containing evidence of Earth's early biosphere are well preserved in the Pilbara Craton of Western Australia. The craton includes part of a protocontinent consisting of granitoid complexes that were emplaced into, and overlain by, a 3.51-2.94 Ga volcanigenic carapace - the Pilbara Supergroup. The craton is overlain by younger supracrustal basins that form a time series recording Earth history from approximately 2.8 Ga to approximately 1.9 Ga. It is proposed that a well-documented suite of these ancient rocks be collected as reference material for Archean and astrobiological research. All samples would be collected in a well-defined geological context in order to build a framework to test models for the early evolution of life on Earth and to develop protocols for the search for life on other planets.

  5. Earth's earliest biosphere-a proposal to develop a collection of curated archean geologic reference materials.

    PubMed

    Lindsay, John F; McKay, David S; Allen, Carlton C

    2003-01-01

    The discovery of evidence indicative of life in a Martian meteorite has led to an increase in interest in astrobiology. As a result of this discovery, and the ensuing controversy, it has become apparent that our knowledge of the early development of life on Earth is limited. Archean stratigraphic successions containing evidence of Earth's early biosphere are well preserved in the Pilbara Craton of Western Australia. The craton includes part of a protocontinent consisting of granitoid complexes that were emplaced into, and overlain by, a 3.51-2.94 Ga volcanigenic carapace - the Pilbara Supergroup. The craton is overlain by younger supracrustal basins that form a time series recording Earth history from approximately 2.8 Ga to approximately 1.9 Ga. It is proposed that a well-documented suite of these ancient rocks be collected as reference material for Archean and astrobiological research. All samples would be collected in a well-defined geological context in order to build a framework to test models for the early evolution of life on Earth and to develop protocols for the search for life on other planets.

  6. Nature Study, Aborigines and the Australian Kindergarten: Lessons from Martha Simpson's "Australian Programme Based on the Life and Customs of the Australian Black"

    ERIC Educational Resources Information Center

    Jones, Jennifer

    2014-01-01

    This article examines an experimental kindergarten programme "Work in the Kindergarten: An Australian Programme based on the Life and Customs of the Australian Black" developed by Martha Simpson in early twentieth-century Australia. Here Simpson adapted international Revisionist Froebelian approaches to cultural epoch theory and nature…

  7. Unique Nature of the Quality of Life in the Context of Extreme Climatic, Geographical and Specific Socio-Cultural Living Conditions

    ERIC Educational Resources Information Center

    Kulik, Anastasia; Neyaskina, Yuliya; Frizen, Marina; Shiryaeva, Olga; Surikova, Yana

    2016-01-01

    This article presents the results of a detailed empirical research, aimed at studying the quality of life in the context of extreme climatic, geographical and specific sociocultural living conditions. Our research is based on the methodological approach including social, economical, ecological and psychological characteristics and reflecting…

  8. Quantifying the environmental impact of an integrated human/industrial-natural system using life cycle assessment; a case study on a forest and wood processing chain.

    PubMed

    Schaubroeck, Thomas; Alvarenga, Rodrigo A F; Verheyen, Kris; Muys, Bart; Dewulf, Jo

    2013-01-01

    Life Cycle Assessment (LCA) is a tool to assess the environmental sustainability of a product; it quantifies the environmental impact of a product's life cycle. In conventional LCAs, the boundaries of a product's life cycle are limited to the human/industrial system, the technosphere. Ecosystems, which provide resources to and take up emissions from the technosphere, are not included in those boundaries. However, similar to the technosphere, ecosystems also have an impact on their (surrounding) environment through their resource usage (e.g., nutrients) and emissions (e.g., CH4). We therefore propose a LCA framework to assess the impact of integrated Techno-Ecological Systems (TES), comprising relevant ecosystems and the technosphere. In our framework, ecosystems are accounted for in the same manner as technosphere compartments. Also, the remediating effect of uptake of pollutants, an ecosystem service, is considered. A case study was performed on a TES of sawn timber production encompassing wood growth in an intensively managed forest ecosystem and further industrial processing. Results show that the managed forest accounted for almost all resource usage and biodiversity loss through land occupation but also for a remediating effect on human health, mostly via capture of airborne fine particles. These findings illustrate the potential relevance of including ecosystems in the product's life cycle of a LCA, though further research is needed to better quantify the environmental impact of TES.

  9. Defending definitions of life.

    PubMed

    Mix, Lucas John

    2015-01-01

    Over the past 10 years, it has become unpopular to talk about definitions of life, under the assumption that attempts at a precise definition are counterproductive. Recent attempts have failed to meet strict philosophical criteria for definitions and have failed to reach consensus. I argue that provisional definitions are necessary for clear communications. Our current knowledge of biology justifies a number of universal claims about the category of life. Whether or not "life" represents a natural category, it maps to a number of important, observable processes. Given the importance of those processes and the extent of our knowledge, plural explicit definitions of life (and related categories) will be necessary for progress in astrobiology and origin-of-life studies as well as biology in general. I propose concrete categories related to, but not necessarily coextensive with, life for clear communication and hypothesis formation: Woese life, Darwin life, Haldane life.

  10. Ordovician earliest Silurian rift tholeiites in the Acatlán Complex, southern Mexico: Evidence of rifting on the southern margin of the Rheic Ocean

    NASA Astrophysics Data System (ADS)

    Keppie, J. Duncan; Dostal, Jaroslav; Miller, Brent V.; Ramos-Arias, M. A.; Morales-Gámez, Miguel; Nance, R. Damian; Murphy, J. Brendan; Ortega-Rivera, Amabel; Lee, J. W. K.; Housh, T.; Cooper, P.

    2008-12-01

    The Acatlán Complex of southern Mexico is a vestige of a Paleozoic Ocean inferred to be either the Cambro-Ordovician Iapetus and/or the Ordovician-Carboniferous Rheic oceans. Ordovician granitoids in the complex have been interpreted as either the products of dehydration melting, arc or rift magmatism, however, the geochemistry of felsic rocks is inconclusive. The geochemistry of a recently discovered, major, Ordovician-earliest Silurian mafic igneous suite associated with these granitoids is critical to defining the tectonic setting of the igneous event, and to paleogeographic reconstructions. Such data from three areas in the Acatlán Complex (Xayacatlán, Patlanoaya, and Cuaulote) document tholeiitic, within-plate characteristics with a source in either primitive mantle or mantle previously modified by subduction-related magmatism possibly combined with crustal contamination. This, combined with their occurrence as a dike swarm intruding rift-passive margin clastic sedimentary rocks, indicates rifting of a continental margin. Mafic dikes at Xayacatlán yielded a concordant U-Pb TIMS zircon age of 442 ± 1 Ma and a 40Ar/ 39Ar hornblende plateau age of 434 ± 3 Ma. The age of mafic magmatism at other localities is defined by the ages of associated granitoids intruded at ca. 461 Ma and by the age of the youngest detrital zircon in the host rocks: 496 ± 25 Ma at Patlanoaya. Previously published age data suggest that this igneous event may have started earlier at 478 ± 5 Ma (Early Ordovician). Although the life spans of the Iapetus and Rheic oceans overlap during the Ordovician, subduction and collision characterize the former, whereas the latter was in a rift-drift mode. Thus, this Ordovician-earliest Silurian magmatism is more consistent with rifting along the southern margin of the Rheic Ocean. Initiation of rifting at ca. 480 Ma is contemporaneous with separation of peri-Gondwanan terranes, such as Avalonia and Carolinia, from Amazonia-Oaxaquia. Subsequent

  11. The feasibility study of small long-life gas cooled fast reactor with mixed natural Uranium/Thorium as fuel cycle input

    SciTech Connect

    Ariani, Menik; Su'ud, Zaki; Waris, Abdul; Khairurrijal,; Monado, Fiber; Sekimoto, Hiroshi

    2012-06-06

    A conceptual design study of Gas Cooled Fast Reactors with Modified CANDLE burn-up scheme has been performed. In this study, design GCFR with Helium coolant which can be continuously operated by supplying mixed Natural Uranium/Thorium without fuel enrichment plant or fuel reprocessing plant. The active reactor cores are divided into two region, Thorium fuel region and Uranium fuel region. Each fuel core regions are subdivided into ten parts (region-1 until region-10) with the same volume in the axial direction. The fresh Natural Uranium and Thorium 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/Thorium fuel. This concept is basically applied to all regions in both cores area, i.e. shifted the core of i{sup th} region into i+1 region after the end of 10 years burn-up cycle. For the next cycles, we will add only Natural Uranium and Thorium on each region-1. The calculation results show the reactivity reached by mixed Natural Uranium/Thorium with volume ratio is 4.7:1. This reactor can results power thermal 550 MWth. After reactor start-up the operation, furthermore reactor only needs Natural Uranium/Thorium supply for continue operation along 100 years.

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

    PubMed

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

    2014-03-01

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

  13. Cenozoic analogues support a plate tectonic origin for the Earth’s earliest continental crust

    NASA Astrophysics Data System (ADS)

    Hastie, A. R.; Kerr, A. C.; Mitchell, S. F.; McDonald, I.; Pearce, J. A.; Millar, I. L.; Wolstencroft, M.

    2009-12-01

    crust. The Newcastle magmas ascended and erupted without coming into contact with a mantle wedge thus forming the low MgO, Ni and Cr contents. Most Cenozoic adakites have compositions similar to the middle-late Archaean TTG suite of igneous rocks. In contrast, early (>3.5 Ga) Archaean TTG crustal rocks have lower Sr, MgO, Ni and Cr concentrations and prior to this study had no modern adakite analogue. However, the Newcastle adakites have similar compositions to the, early Archaean TTG. The discovery of these rocks has important implications for our understanding of the formation of the Earth’s earliest continental crust and so it is proposed that the Newcastle lavas be classified as a unique sub-group of adakites: Jamaican-type adakite.

  14. The earliest phases of high-mass star formation: the NGC 6334-NGC 6357 complex

    NASA Astrophysics Data System (ADS)

    Russeil, D.; Zavagno, A.; Motte, F.; Schneider, N.; Bontemps, S.; Walsh, A. J.

    2010-06-01

    Context. Our knowledge of high-mass star formation has been mainly based on follow-up studies of bright sources found by IRAS, and has thus been incomplete for its earliest phases, which are inconspicuous at infrared wavelengths. With a new generation of powerful bolometer arrays, unbiased large-scale surveys of nearby high-mass star-forming complexes now search for the high-mass analog of low-mass cores and class 0 protostars. Aims: Following the pioneering study of Cygnus X, we investigate the star-forming region NGC 6334-NGC 6357 (~1.7 kpc). Methods: We study the complex NGC 6334-NGC 6357 in an homogeneous way following the previous work of Motte and collaborators. We used the same method to extract the densest cores which are the most likely sites for high-mass star formation. We analyzed the SIMBA/SEST 1.2 mm data presented in Munoz and coworkers, which covers all high-column density areas (A v ≥ 15 mag) of the NGC 6334-NGC 6357 complex and extracted dense cores following the method used for Cygnus X. We constrain the properties of the most massive dense cores (M > 100 M_⊙) using new molecular line observations (as SiO, N2H+,H13CO+, HCO+ (1-0) and CH3CN) with Mopra and a complete cross-correlation with infrared databases (MSX, GLIMPSE, MIPSGAL) and literature. Results: We extracted 163 massive dense cores of which 16 are more massive than 200 M_⊙. These high-mass dense cores have a typical FWHM size of 0.37 pc, an average mass of M ~ 600 M_⊙, and a volume-averaged density of ~ 1.5 × 105 cm-3. Among these massive dense cores, 6 are good candidates for hosting high-mass infrared-quiet protostars, 9 cores are classified as high-luminosity infrared protostars, and we find only one high-mass starless clump (~0.3 pc, ~ 4 × 104 cm-3) that is gravitationally bound. Conclusions: Since our sample is derived from a single molecular complex and covers every embedded phase of high-mass star formation, it provides a statistical estimate of the lifetime of massive

  15. New insights into the earliest Quaternary environments in the Central North Sea from 3D seismic

    NASA Astrophysics Data System (ADS)

    Lamb, Rachel; Huuse, Mads; Stewart, Margaret; Brocklehurst, Simon H.

    2014-05-01

    In the past the transition between an unconformable surface in the south to a conformable horizon towards the north has made identification and mapping the base-Quaternary in the central North Sea difficult (Sejrup et al 1991; Gatliff et al 1994). However recent integration of biostratigraphy, pollen analysis, paleomagnetism and amino acid analysis in the Dutch and Danish sectors (Rasmussen et al 2005; Kuhlmann et al 2006) has allowed greater confidence in the correlation to the region 3D seismic datasets and thus has allowed the base-Quaternary to be mapped across the entire basin. The base-Quaternary has been mapped using the PGS MegaSurvey dataset from wells in the Danish Sector along the initially unconformable horizon and down the delta front into the more conformable basin giving a high degree of confidence in the horizon pick. The revised base-Quaternary surface reaches a depth of 1248 ms TWT with an elongate basin shape which is significantly deeper than the traditionally mapped surface. Using RMS amplitudes and other seismic attributes the revised base-Quaternary has been investigated along the horizon and in time slice to interpret the environments of the earliest Quaternary prior to the onset of glaciation. Combined with analysis of aligned elongate furrows over 10 km long, 100 m wide and 100 m deep suggest a deep marine environment in an almost enclosed basin with persistent strong NW-SE bottom currents in the deepest parts. Pockmarks were formed by the escape of shallow gas on the sides of a small delta in the eastern part of the basin. The progradation of large deltas from both the north and south into the basin make up the majority of the deposition of sediment into the basin. Key Words: base-Quaternary; seismic interpretation; paleoenvironments References: Gatliff, R.W, Richards, P.C, Smith, K, Graham, C.C, McCormac, M, Smith, N.J.P, Long, D, Cameron, T.D.J, Evans, D, Stevenson, A.G, Bulat, J, Ritchie, J.D, (1994) 'United Kingdom offshore regional

  16. Earth's Earliest Ecosystems in the C: The Use of Microbial Mats to Demonstrate General Principles of Scientific Inquiry and Microbial Ecology

    NASA Technical Reports Server (NTRS)

    Bebout, Brad M.; Bucaria, Robin

    2006-01-01

    Microbial mats are living examples of the most ancient biological communities on Earth. As Earth's earliest ecosystems, they are centrally important to understanding the history of life on our planet and are useful models for the search for life elsewhere. As relatively compact (but complete) ecosystems, microbial mats are also extremely useful for educational activities. Mats may be used to demonstrate a wide variety of concepts in general and microbial ecology, including the biogeochemical cycling of elements, photosynthesis and respiration, and the origin of the Earth's present oxygen containing atmosphere. Microbial mats can be found in a number of common environments accessible to teachers, and laboratory microbial mats can be constructed using materials purchased from biological supply houses. With funding from NASA's Exobiology program, we have developed curriculum and web-based activities centered on the use of microbial mats as tools for demonstrating general principles in ecology, and the scientific process. Our web site (http://microbes.arc.nasa.gov) includes reference materials, lesson plans, and a "Web Lab", featuring living mats maintained in a mini-aquarium. The site also provides information as to how research on microbial mats supports NASA's goals, and various NASA missions. A photo gallery contains images of mats, microscopic views of the organisms that form them, and our own research activities. An animated educational video on the web site uses computer graphic and video microscopy to take students on a journey into a microbial mat. These activities are targeted to a middle school audience and are aligned with the National Science Standards.

  17. Comparison of life history traits of Tanais dulongii (Tanaidacea: Tanaididae) in natural and artificial marine environments of the south-western Atlantic

    NASA Astrophysics Data System (ADS)

    Rumbold, Carlos E.; Obenat, Sandra M.; Spivak, Eduardo D.

    2015-06-01

    Tanaidaceans are small benthic crustaceans with a strictly benthic life cycle and low dispersion rates, so they are good candidates to evaluate the effects of environment over life history strategies and reproductive biology. In this work, we studied two populations of Tanais dulongii (Audouin, 1826) that live in two contrasting habitats in order to determine whether they differ in life history traits. The animals were obtained by systematic sampling in a rocky shore with a lower anthropic impact (La Estafeta: LE) and a polluted area (Mar del Plata harbour: MdP) from March 2011 to March 2012. Seawater temperature and salinity did not differ between sites, but MdP showed more acid and hypoxic conditions than LE. Population density was homogeneous and lower in MdP (ca. 20 ind/100 gr) than that in LE where density varied between 250 and 800 ind/100 gr. Reproductive individuals and juveniles were always present, and both populations showed two main recruitment periods: the first in spring in both populations, and the second in summer in MdP but in autumn-winter in LE. In both populations, sex ratio was strongly female-biased. Juveniles, females and males from LE had larger sizes than that from MdP and reached their sexual differentiation at larger sizes. The estimated lifespan was about 9 and 12 months in MdP and LE, respectively. This study suggests that the differences observed between populations of T. dulongii in life history traits are intimately related to environmental differences in pH and dissolved oxygen between habitats, but should not be discarded a synergistic effect of temperature, organic pollution, food availability and predation pressure.

  18. Facilitated by nature and agriculture: performance of a specialist herbivore improves with host-plant life history evolution, domestication, and breeding.

    PubMed

    Dávila-Flores, Amanda M; DeWitt, Thomas J; Bernal, Julio S

    2013-12-01

    Plant defenses against herbivores are predicted to change as plant lineages diversify, and with domestication and subsequent selection and breeding in the case of crop plants. We addressed whether defense against a specialist herbivore declined coincidently with life history evolution, domestication, and breeding within the grass genus Zea (Poaceae). For this, we assessed performance of corn leafhopper (Dalbulus maidis) following colonization of one of four Zea species containing three successive transitions: the evolutionary transition from perennial to annual life cycle, the agricultural transition from wild annual grass to primitive crop cultivar, and the agronomic transition from primitive to modern crop cultivar. Performance of corn leafhopper was measured through seven variables relevant to development speed, survivorship, fecundity, and body size. The plants included in our study were perennial teosinte (Zea diploperennis), Balsas teosinte (Zea mays parviglumis), a landrace maize (Zea mays mays), and a hybrid maize. Perennial teosinte is a perennial, iteroparous species, and is basal in Zea; Balsas teosinte is an annual species, and the progenitor of maize; the landrace maize is a primitive, genetically diverse cultivar, and is ancestral to the hybrid maize; and, the hybrid maize is a highly inbred, modern cultivar. Performance of corn leafhopper was poorest on perennial teosinte, intermediate on Balsas teosinte and landrace maize, and best on hybrid maize, consistent with our expectation of declining defense from perennial teosinte to hybrid maize. Overall, our results indicated that corn leafhopper performance increased most with the agronomic transition, followed by the life history transition, and least with the domestication transition.

  19. An Analysis on the Level of Leisure Satisfaction and the Level of Satisfaction with Life of Young People Who Attend Sport Education Camps in Nature

    ERIC Educational Resources Information Center

    Ercan, Polat

    2016-01-01

    This study analyzes the influence of leisure satisfaction on young people who attended the sport education camp in Bolu city. Target group of the study are students who have participated in the activities called "Nature Camp for Youth" which is held annually by Youth and Sport Ministry. The age range of the target group is between 17 and…

  20. Compensatory cortical activation observed by fMRI during a cognitive task at the earliest stage of MS.

    PubMed

    Audoin, Bertrand; Ibarrola, Danielle; Ranjeva, Jean-Philippe; Confort-Gouny, Sylviane; Malikova, Irina; Ali-Chérif, André; Pelletier, Jean; Cozzone, Patrick

    2003-10-01

    Recent functional magnetic resonance imaging (fMRI) studies have suggested that functional cortical changes seen in patients with early relapsing-remitting multiple sclerosis (MS) can have an adaptive role to limit the clinical impact of tissue injury. To determine whether cortical reorganization occurs during high cognitive processes at the earliest stage of multiple sclerosis (MS), we performed an fMRI experiment using the conventional Paced Auditory Serial Addition Test (PASAT) as paradigm in a population of ten patients with clinically isolated syndrome suggestive of multiple sclerosis (CISSMS). At the time of the fMRI exploration, mean disease duration was 6.8 +/- 3.3 months. We compared these results to those obtained in a group of ten education-, age-, and sex-matched healthy controls. Subjects were explored on a 1.5 T MRI system using single-shot gradient-echo EPI sequence. Performances of the two groups during PASAT recorded inside the MR scanner were not different. Statistical assessment of brain activation was based on the random effect analysis (between-group analysis two-sample t-test P < 0.005 confirmed by individual analyses performed in the surviving regions P < 0.05 Mann Whitney U-test). Compared to controls, patients showed significantly greater activation in the right frontopolar cortex, the bilateral lateral prefrontal cortices, and the right cerebellum. Healthy controls did not show greater activation compared to CISSMS patients. The present study argues in favor of the existence of compensatory cortical activations at the earliest stage of MS mainly located in regions involved in executive processing in patients performing PASAT. It also suggests that fMRI can evidence the active processes of neuroplasticity contributing to mask the clinical cognitive expression of brain pathology at the earliest stage of MS.

  1. Step initiation interferes with working memory in nondisabled patients with the earliest multiple sclerosis-A dual-task study.

    PubMed

    Brecl Jakob, G; Remšak, T; Šega Jazbec, S; Horvat Ledinek, A; Rot, U

    2017-01-01

    Balance and cognition are affected by multiple sclerosis (MS). Cognitive-motor interference (CMI) is important for balance impairment in MS, however little is known about CMI at the earliest stages of the disease. Step initiation (SI) with anticipatory postural adjustments (APAs) has been linked to postural instability and falls in subjects with MS, therefore we aimed to assess CMI between SI and the two storage systems of working memory in patients with clinically isolated syndrome (presented as optic neuritis-ON) suggestive of MS. Twenty patients with normal/near normal visual acuity and 20 age-, weight-, height-, sex- and education-matched control subjects were included. APAs were studied using center of pressure measures in three conditions: SI alone, SI+Brooks' spatial- and SI+2-back verbal working memory task. Decrements (% change) in performance on cognitive tasks and in APA parameters were calculated. CMI was assessed combining the two decrements scores. Performance on both cognitive tasks was more affected by dual-tasking in patients compared to healthy subjects. In both groups APA parameters were not influenced by dual-tasking. CMI was higher in patients compared to healthy subjects. Our results suggest that the disease affects CMI in its earliest stages. Since both cognitive tasks were similarly affected by dual-tasking in patients and controls central executive seems to play the major role in CMI between SI and working memory. Patients prioritizing motor over cognitive task for balance maintenance suggests reduced divided attention capacity as a cause of increased CMI in the earliest MS.

  2. The Breath of Life. The Problem of Poisoned Air.

    ERIC Educational Resources Information Center

    Carr, Donald E.

    The origins and nature of air pollution, from earliest days to the present, are examined in this book. Although air pollution has been with us since the discovery of fire, it is proffered that the major culprit now is the burning of gasoline and low-grade heating oil. All other sources of air pollution are negligible. The main thesis is that only…

  3. Detection of RHDV strains in the Iberian hare (Lepus granatensis): earliest evidence of rabbit lagovirus cross-species infection.

    PubMed

    Lopes, Ana M; Marques, Sara; Silva, Eliane; Magalhães, Maria J; Pinheiro, Ana; Alves, Paulo C; Le Pendu, Jacques; Esteves, Pedro J; Thompson, Gertrude; Abrantes, Joana

    2014-09-24

    Rabbit hemorrhagic disease virus (RHDV) is a highly lethal Lagovirus, family Caliciviridae, that threatens European rabbits (Oryctolagus cuniculus). Although a related virus severely affects hares, cross-species infection was only recently described for new variant RHDV in Cape hares (Lepus capensis mediterraneus). We sequenced two strains from dead Iberian hares (Lepus granatensis) collected in the 1990s in Portugal. Clinical signs were compatible with a Lagovirus infection. Phylogenetic analysis of the complete capsid gene positioned them in the RHDV genogroup that circulated on the Iberian Peninsula at that time. This is the earliest evidence of RHDV affecting a species other than European rabbits.

  4. Short-term follow-up of exercise training program and beta-blocker treatment on quality of life in dogs with naturally acquired chronic mitral valve disease

    PubMed Central

    Marcondes-Santos, M.; Mansur, A.P.; Fragata, F.S.; Strunz, C.M.C.

    2015-01-01

    This study aimed to evaluate the effects of carvedilol treatment and a regimen of supervised aerobic exercise training on quality of life and other clinical, echocardiographic, and biochemical variables in a group of client-owned dogs with chronic mitral valve disease (CMVD). Ten healthy dogs (control) and 36 CMVD dogs were studied, with the latter group divided into 3 subgroups. In addition to conventional treatment (benazepril, 0.3-0.5 mg/kg once a day, and digoxin, 0.0055 mg/kg twice daily), 13 dogs received exercise training (subgroup I; 10.3±2.1 years), 10 dogs received carvedilol (0.3 mg/kg twice daily) and exercise training (subgroup II; 10.8±1.7 years), and 13 dogs received only carvedilol (subgroup III; 10.9±2.1 years). All drugs were administered orally. Clinical, laboratory, and Doppler echocardiographic variables were evaluated at baseline and after 3 and 6 months. Exercise training was conducted from months 3-6. The mean speed rate during training increased for both subgroups I and II (ANOVA, P>0.001), indicating improvement in physical conditioning at the end of the exercise period. Quality of life and functional class was improved for all subgroups at the end of the study. The N-terminal pro-brain natriuretic peptide (NT-proBNP) level increased in subgroup I from baseline to 3 months, but remained stable after training introduction (from 3 to 6 months). For subgroups II and III, NT-proBNP levels remained stable during the entire study. No difference was observed for the other variables between the three evaluation periods. The combination of carvedilol or exercise training with conventional treatment in CMVD dogs led to improvements in quality of life and functional class. Therefore, light walking in CMVD dogs must be encouraged. PMID:26445331

  5. Life sciences and space research 25 (3): Natural and artifical ecosystems; Meeting F4 of the COSPAR Plenary Meeting, 29th, Washington, DC, Aug. 28-Sep. 5, 1992

    NASA Technical Reports Server (NTRS)

    Macelroy, R. D. (Editor); Mitchell, C. A. (Editor); Andre, M. (Editor); Blackwell, C. C. (Editor); Tibbitts, T. W. (Editor); Banin, A. (Editor); Levine, J. S. (Editor)

    1994-01-01

    Bioregenerative life support systems will be an essential part of long duration manned space flight. Studies have been made of various components of these closed ecological systems. these studies have included those spaceborne experiments on Spacelab and Mir, as well as ground-based simulations. The effects of reduced gravity include alterations in food crop and other plant growth and vigor. Systems have also been designed and tested to provide a balanced regenerative system that recycles airborne and other wastes while providing nutrients and other input for future cycles. Hydroponic cultivation must include control of pathogens. All closed systems require sensing and automatic control.

  6. On a quantum mechanical system theory of the origin of life: from the Stapp-model to the origin of natural symbols

    NASA Astrophysics Data System (ADS)

    Balázs, András

    2016-01-01

    The Heisenberg-James-Stapp (quantum mechanical) mind model is surveyed and criticized briefly. The criticism points out that the model, while being essentially consistent concerning (human) consciousness, fundamentally lacks the evolutional point of view both onto- and phylogenetically. Ethology and other than Jamesian psychology is quoted and a quantum mechanical theoretical scheme is suggested to essentially extend Stapp's frame in an evolutionary context. It is proposed that its central supposition, spontaneous quantum measurement can be better utilized in an investigation of the origin of the "subjective" process, having come about concomitantly with the chemistry of the origin of life. We dwell on its applicability at this latter process, at its heart standing, it is supposed, the endophysical nonlinear "self-measurement" of (quantum mechanically describable) matter, and so our investigation is extended to this primeval phenomenon. It is suggested that the life phenomenon is an indirect C* → (W*) → C* quantum algebraic process transition, where the (W*) system would represent the living state. Summarized also are our previous results on an internalized, "reversed", time process, introduced originally by Gunji, which is subordinated to the external "forwards" time evolution, driving towards symmetry by gradual space-mappings, where the original splitting-up must have come about in a spontaneous symmetry breaking nonlinear "self-measurement" of matter in an endophysical World.

  7. Combination of high-intensity pulsed electric fields with natural antimicrobials to inactivate pathogenic microorganisms and extend the shelf-life of melon and watermelon juices.

    PubMed

    Mosqueda-Melgar, Jonathan; Raybaudi-Massilia, Rosa M; Martín-Belloso, Olga

    2008-05-01

    The effect of high-intensity pulsed electric field (HIPEF) combined with citric acid (0.5-2.0%, w/v) or cinnamon bark oil (0.05-0.30%, w/v) against populations of Escherichia coli O157:H7, Salmonella Enteritidis and Listeria monocytogenes in melon and watermelon juices were evaluated. Microbiological shelf-life and sensory attributes were also determined. Populations of E. coli O157:H7, S. Enteritidis and L. monocytogenes were reduced by more than 5.0log(10)CFU/ml in HIPEF-processed melon (35kV/cm for 1709 micros at 193Hz and 4 micros pulse duration) and watermelon (35kV/cm for 1682 micros at 193Hz and 4 micros pulse duration) juices containing 2.0% and 1.5% of citric acid, respectively, or 0.2% of cinnamon bark oil. In addition, these treatments were also able to inactivate mesophilic, psychrophilic and, molds and yeasts populations, leading to a shelf-life of more than 91 days in both juices stored at 5 degrees C. Hence, the microbiological quality and safety of these fruit juices by combining HIPEF and citric acid or cinnamon bark oil were ensured. However, the taste and odor in those HIPEF-treated melon and watermelon juices containing antimicrobials were significantly affected. Therefore, further studies are needed to decrease the impact on the sensory attributes by using antimicrobials.

  8. Response of life-history traits to artificial and natural selection for virulence and nonvirulence in a Drosophila parastitoid, Asobara tabida.

    PubMed

    Moiroux, Joffrey; van Baaren, Joan; Poyet, Mathilde; Couty, Aude; Eslin, Patrice; Prévost, Geneviève; Séguin, Jérémy; Le Roux, Vincent

    2016-12-12

    Co-evolution of host-parasitoid interactions is determined by the costs of host resistance, which received empirical evidence, and the costs of parasitoid virulence, which have been mostly hypothesized. Asobara tabida is a parasitoid, which mainly parasitizes Drosophila melanogaster and D. subobscura, the first species being able to resist to the parasitoid development while the second species is not. To parasitize resistant hosts, including D. melanogaster, A. tabida develops sticky eggs, which prevent encapsulation, but this virulence mechanism may be costly. Interindividual and interpopulation variation in the proportion of sticky eggs respectively allowed us to (i) artificially select and compare life-history traits of a virulent and a nonvirulent laboratory strain, and (ii) compare a virulent and a nonvirulent field strain, to investigate the hypothetical costs of virulence. We observed strong differences between the 2 laboratory strains. The nonvirulent strain invested fewer resources in reproduction and walked less than the virulent one but lived longer. Concerning the field strains, we observed that the nonvirulent strain had larger wings while the virulent one walked more and faster. All together, our results suggest that virulence may not always be costly, but rather that different life histories associated with different levels of virulence may coexist at both intra- and interpopulation levels.

  9. The Search for Life from Antarctica to Mars

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    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. Human exploration of Mars will probably begin with a small base manned by a temporary crew, a necessary first start. But exploration of the entire planet win require a continued presence on the Martian surface and the development of a self sustaining community in which humans can live and work for very long periods of time. A permanent Mars research base can be compared to the permanent research bases which several nations maintain in Antarctica at the South Pole, the geomagnetic pole, and elsewhere. In the long run, a continued human presence on Mars will be t he most economical way to study that planet in detail. It is possible that at some time in the future we might recreate a habitable climate on Mars, returning it to the life-bearing state it may have enjoyed early in its history. Our studies of Mars are still in a preliminary state but everything we have learned suggests that it may be possible to restore Mars to a habitable climate.

  10. The earliest maize from San Marcos Tehuacán is a partial domesticate with genomic evidence of inbreeding

    PubMed Central

    Vallebueno-Estrada, Miguel; Rodríguez-Arévalo, Isaac; Rougon-Cardoso, Alejandra; Martínez González, Javier; García Cook, Angel; Vielle-Calzada, Jean-Philippe

    2016-01-01

    Pioneering archaeological expeditions lead by Richard MacNeish in the 1960s identified the valley of Tehuacán as an important center of early Mesoamerican agriculture, providing by far the widest collection of ancient crop remains, including maize. In 2012, a new exploration of San Marcos cave (Tehuacán, Mexico) yielded nonmanipulated maize specimens dating at a similar age of 5,300–4,970 calibrated y B.P. On the basis of shotgun sequencing and genomic comparisons to Balsas teosinte and modern maize, we show herein that the earliest maize from San Marcos cave was a partial domesticate diverging from the landraces and containing ancestral allelic variants that are absent from extant maize populations. Whereas some domestication loci, such as teosinte branched1 (tb1) and brittle endosperm2 (bt2), had already lost most of the nucleotide variability present in Balsas teosinte, others, such as teosinte glume architecture1 (tga1) and sugary1 (su1), conserved partial levels of nucleotide variability that are absent from extant maize. Genetic comparisons among three temporally convergent samples revealed that they were homozygous and identical by descent across their genome. Our results indicate that the earliest maize from San Marcos was already inbred, opening the possibility for Tehuacán maize cultivation evolving from reduced founder populations of isolated and perhaps self-pollinated individuals. PMID:27872313

  11. Boreal earliest Triassic biotas elucidate globally depauperate hard substrate communities after the end-Permian mass extinction.

    PubMed

    Zatoń, Michał; Niedźwiedzki, Grzegorz; Blom, Henning; Kear, Benjamin P

    2016-11-08

    The end-Permian mass extinction constituted the most devastating biotic crisis of the Phanerozoic. Its aftermath was characterized by harsh marine conditions incorporating volcanically induced oceanic warming, widespread anoxia and acidification. Bio-productivity accordingly experienced marked fluctuations. In particular, low palaeolatitude hard substrate communities from shallow seas fringing Western Pangaea and the Tethyan Realm were extremely impoverished, being dominated by monogeneric colonies of filter-feeding microconchid tubeworms. Here we present the first equivalent field data for Boreal hard substrate assemblages from the earliest Triassic (Induan) of East Greenland. This region bordered a discrete bio-realm situated at mid-high palaeolatitude (>30°N). Nevertheless, hard substrate biotas were compositionally identical to those from elsewhere, with microconchids encrusting Claraia bivalves and algal buildups on the sea floor. Biostratigraphical correlation further shows that Boreal microconchids underwent progressive tube modification and unique taxic diversification concordant with changing habitats over time. We interpret this as a post-extinction recovery and adaptive radiation sequence that mirrored coeval subequatorial faunas, and thus confirms hard substrate ecosystem depletion as a hallmark of the earliest Triassic interval globally.

  12. Boreal earliest Triassic biotas elucidate globally depauperate hard substrate communities after the end-Permian mass extinction

    PubMed Central

    Zatoń, Michał; Niedźwiedzki, Grzegorz; Blom, Henning; Kear, Benjamin P.

    2016-01-01

    The end-Permian mass extinction constituted the most devastating biotic crisis of the Phanerozoic. Its aftermath was characterized by harsh marine conditions incorporating volcanically induced oceanic warming, widespread anoxia and acidification. Bio-productivity accordingly experienced marked fluctuations. In particular, low palaeolatitude hard substrate communities from shallow seas fringing Western Pangaea and the Tethyan Realm were extremely impoverished, being dominated by monogeneric colonies of filter-feeding microconchid tubeworms. Here we present the first equivalent field data for Boreal hard substrate assemblages from the earliest Triassic (Induan) of East Greenland. This region bordered a discrete bio-realm situated at mid-high palaeolatitude (>30°N). Nevertheless, hard substrate biotas were compositionally identical to those from elsewhere, with microconchids encrusting Claraia bivalves and algal buildups on the sea floor. Biostratigraphical correlation further shows that Boreal microconchids underwent progressive tube modification and unique taxic diversification concordant with changing habitats over time. We interpret this as a post-extinction recovery and adaptive radiation sequence that mirrored coeval subequatorial faunas, and thus confirms hard substrate ecosystem depletion as a hallmark of the earliest Triassic interval globally. PMID:27821855

  13. Boreal earliest Triassic biotas elucidate globally depauperate hard substrate communities after the end-Permian mass extinction

    NASA Astrophysics Data System (ADS)

    Zatoń, Michał; Niedźwiedzki, Grzegorz; Blom, Henning; Kear, Benjamin P.

    2016-11-01

    The end-Permian mass extinction constituted the most devastating biotic crisis of the Phanerozoic. Its aftermath was characterized by harsh marine conditions incorporating volcanically induced oceanic warming, widespread anoxia and acidification. Bio-productivity accordingly experienced marked fluctuations. In particular, low palaeolatitude hard substrate communities from shallow seas fringing Western Pangaea and the Tethyan Realm were extremely impoverished, being dominated by monogeneric colonies of filter-feeding microconchid tubeworms. Here we present the first equivalent field data for Boreal hard substrate assemblages from the earliest Triassic (Induan) of East Greenland. This region bordered a discrete bio-realm situated at mid-high palaeolatitude (>30°N). Nevertheless, hard substrate biotas were compositionally identical to those from elsewhere, with microconchids encrusting Claraia bivalves and algal buildups on the sea floor. Biostratigraphical correlation further shows that Boreal microconchids underwent progressive tube modification and unique taxic diversification concordant with changing habitats over time. We interpret this as a post-extinction recovery and adaptive radiation sequence that mirrored coeval subequatorial faunas, and thus confirms hard substrate ecosystem depletion as a hallmark of the earliest Triassic interval globally.

  14. Earliest known unequivocal rhinocerotoid sheds new light on the origin of Giant Rhinos and phylogeny of early rhinocerotoids

    PubMed Central

    Wang, Haibing; Bai, Bin; Meng, Jin; Wang, Yuanqing

    2016-01-01

    Forstercooperiines are a group of primitive rhinocerotoids with a relatively large body size in the Eocene, and normally considered to be closely related to Giant Rhinos. Here we report a new forstercooperiine, Pappaceras meiomenus sp. nov., from the late Early Eocene Arshanto Formation, Erlian Basin, Nei Mongol, China. Pappaceras is the earliest known unequivocal rhinocerotoid, and the holotype of the new species, represented by the most complete cranium of forstercooperiines known to date, shows the earliest evidence of reduction of the first upper premolar in rhinocerotoids, and resembles paraceratheriine Juxia in basicranial features, supporting the interpretation that the forstercooperiine clade is ancestral to paraceratheriines. The new species also displays some similarities with amynodontids in craniodental structures. Phylogenetic analysis identifies P. meiomenus as a basal taxon of the monophyletic forstercooperiines. It also reveals novel phylogenetic relationships of early rhinocerotoids that indicates Uintaceras is the sister group of paraceratheriids, to which amynodontids are more closely related than to any other group of rhinocerotoids. Furthermore, the eggysodontid clade is excluded from hyracodontids and placed as the sister group of rhinocerotids. Hyracodontidae, excluding paraceratheriids and eggysodontids, is placed as the most basal group of the rhinocerotoids. PMID:28000789

  15. The earliest maize from San Marcos Tehuacán is a partial domesticate with genomic evidence of inbreeding.

    PubMed

    Vallebueno-Estrada, Miguel; Rodríguez-Arévalo, Isaac; Rougon-Cardoso, Alejandra; Martínez González, Javier; García Cook, Angel; Montiel, Rafael; Vielle-Calzada, Jean-Philippe

    2016-12-06

    Pioneering archaeological expeditions lead by Richard MacNeish in the 1960s identified the valley of Tehuacán as an important center of early Mesoamerican agriculture, providing by far the widest collection of ancient crop remains, including maize. In 2012, a new exploration of San Marcos cave (Tehuacán, Mexico) yielded nonmanipulated maize specimens dating at a similar age of 5,300-4,970 calibrated y B.P. On the basis of shotgun sequencing and genomic comparisons to Balsas teosinte and modern maize, we show herein that the earliest maize from San Marcos cave was a partial domesticate diverging from the landraces and containing ancestral allelic variants that are absent from extant maize populations. Whereas some domestication loci, such as teosinte branched1 (tb1) and brittle endosperm2 (bt2), had already lost most of the nucleotide variability present in Balsas teosinte, others, such as teosinte glume architecture1 (tga1) and sugary1 (su1), conserved partial levels of nucleotide variability that are absent from extant maize. Genetic comparisons among three temporally convergent samples revealed that they were homozygous and identical by descent across their genome. Our results indicate that the earliest maize from San Marcos was already inbred, opening the possibility for Tehuacán maize cultivation evolving from reduced founder populations of isolated and perhaps self-pollinated individuals.

  16. Run reconstruction and life-history model. Fish/shellfish study number 28. Exxon Valdez oil spill state/federal natural resource damage assessment final report

    SciTech Connect

    Geiger, H.J.; Templin, W.D.; Collie, J.S.; Quinn, T.J.

    1995-08-01

    The Exxon Valdez oil spill resulted in contaminants of juvenile pink salmon (Oncorhynchus gorbuscha) habitat, including freshwater spawning areas in southwestern Prince William Sound (PWS). The authors estimated the loss of returning wild adult pink salmon in 1990-1992, and speculated about this loss in 1993-1994. The primary cause of death was direct poisoning in the embryo stage of development. These studies have low statistical power to detect oil spill effects in the pre- and post- emergent fry and ocean life stages, therefore the true extent of the injury may be understated. The egg-mortality levels increased in the oiled areas in the 1991 and 1992 brood years. The authors also report on a run-reconstruction model, a deterministic model that assumed Markovian transition probabilities for the migration of each individual stock. The authors` most important finding is that of excessive harvest rates on pink salmon stocks in the northern and northwestern part of PWS.

  17. The Changing Nature of Scientific Sharing and Withholding in Academic Life Sciences Research: Trends From National Surveys in 2000 and 2013

    PubMed Central

    Zinner, Darren E.; Pham-Kanter, Genevieve; Campbell, Eric G.

    2015-01-01

    Purpose Since 2000, federal funders and many journals have established policies requiring more open sharing of data and materials post-publication, primarily through online supplements and third-party repositories. This study examined changes in sharing and withholding practices among academic life scientists, particularly geneticists, between 2000 and 2013. Method In 2000 and 2013, the authors surveyed separate samples of 3,000 academic life scientists at the 100 U.S. universities receiving the most NIH funding. Respondents were asked to estimate the number of requests for information, data, and materials they made to and received from other academic researchers in the past three years. They were also asked about potential consequences of sharing and withholding. Results Response rates were 63.9% (1,849/2,893) in 2000 and 40.8% (1,165/2,853) in 2013. Proportions of faculty in 2000 and 2013 who received, denied, made, or were denied at least one request were not statistically different. However, the total volume of requests received from or made to other scientists dropped substantially (19.4 received in 2000 vs. 10.8 in 2013, P < .001; 8.4 made in 2000 vs. 6.6 in 2013, P < .001). Faculty in 2013 also made an average of 8.4 requests to third-party repositories. Researchers in 2013 were less likely to report that sharing resulted in new research or new collaborations. Conclusions The results show a dramatic shift in sharing mechanisms, moving away from a peer-to-peer sharing model toward one based on central repositories. This may increase efficiency, but collaborations may suffer if personal communication among scientists is deemphasized. PMID:26675188

  18. Earliest datable records of aurora-like phenomena in the astronomical diaries from Babylonia

    NASA Astrophysics Data System (ADS)

    Hayakawa, Hisashi; Mitsuma, Yasuyuki; Ebihara, Yusuke; Kawamura, Akito Davis; Miyahara, Hiroko; Tamazawa, Harufumi; Isobe, Hiroaki

    2016-11-01

    The astronomical diaries from Babylonia (ADB) are excellent sources of information of natural phenomena, including astronomical ones, in pre-Christ era because it contains the record of highly continuous and systematic observations. In this article, we present results of a survey of aurora-like phenomena in ADB, spanning from BCE 652 to BCE 61. We have found nine records of aurora-like phenomena. Philological and scientific examinations suggest that five of them can be considered as likely candidate for aurora observations. They provide unique information about the solar and aurora activities in the first millennium BCE. [Figure not available: see fulltext.

  19. Earliest datable records of aurora-like phenomena in the astronomical diaries from Babylonia.

    PubMed

    Hayakawa, Hisashi; Mitsuma, Yasuyuki; Ebihara, Yusuke; Kawamura, Akito Davis; Miyahara, Hiroko; Tamazawa, Harufumi; Isobe, Hiroaki

    2016-01-01

    The astronomical diaries from Babylonia (ADB) are excellent sources of information of natural phenomena, including astronomical ones, in pre-Christ era because it contains the record of highly continuous and systematic observations. In this article, we present results of a survey of aurora-like phenomena in ADB, spanning from BCE 652 to BCE 61. We have found nine records of aurora-like phenomena. Philological and scientific examinations suggest that five of them can be considered as likely candidate for aurora observations. They provide unique information about the solar and aurora activities in the first millennium BCE. Graphical abstract.

  20. Deciphering death: a commentary on Gompertz (1825) ‘On the nature of the function expressive of the law of human mortality, and on a new mode of determining the value of life contingencies’

    PubMed Central

    Kirkwood, Thomas B. L.

    2015-01-01

    In 1825, the actuary Benjamin Gompertz read a paper, ‘On the nature of the function expressive of the law of human mortality, and on a new mode of determining the value of life contingencies’, to the Royal Society in which he showed that over much of the adult human lifespan, age-specific mortality rates increased in an exponential manner. Gompertz's work played an important role in shaping the emerging statistical science that underpins the pricing of life insurance and annuities. Latterly, as the subject of ageing itself became the focus of scientific study, the Gompertz model provided a powerful stimulus to examine the patterns of death across the life course not only in humans but also in a wide range of other organisms. The idea that the Gompertz model might constitute a fundamental ‘law of mortality’ has given way to the recognition that other patterns exist, not only across the species range but also in advanced old age. Nevertheless, Gompertz's way of representing the function expressive of the pattern of much of adult mortality retains considerable relevance for studying the factors that influence the intrinsic biology of ageing. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society. PMID:25750242

  1. Deciphering death: a commentary on Gompertz (1825) 'On the nature of the function expressive of the law of human mortality, and on a new mode of determining the value of life contingencies'.

    PubMed

    Kirkwood, Thomas B L

    2015-04-19

    In 1825, the actuary Benjamin Gompertz read a paper, 'On the nature of the function expressive of the law of human mortality, and on a new mode of determining the value of life contingencies', to the Royal Society in which he showed that over much of the adult human lifespan, age-specific mortality rates increased in an exponential manner. Gompertz's work played an important role in shaping the emerging statistical science that underpins the pricing of life insurance and annuities. Latterly, as the subject of ageing itself became the focus of scientific study, the Gompertz model provided a powerful stimulus to examine the patterns of death across the life course not only in humans but also in a wide range of other organisms. The idea that the Gompertz model might constitute a fundamental 'law of mortality' has given way to the recognition that other patterns exist, not only across the species range but also in advanced old age. Nevertheless, Gompertz's way of representing the function expressive of the pattern of much of adult mortality retains considerable relevance for studying the factors that influence the intrinsic biology of ageing. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society.

  2. Testing models of dental development in the earliest bony vertebrates, Andreolepis and Lophosteus.

    PubMed

    Cunningham, John A; Rücklin, Martin; Blom, Henning; Botella, Hector; Donoghue, Philip C J

    2012-10-23

    Theories on the development and evolution of teeth have long been biased by the fallacy that chondrichthyans reflect the ancestral condition for jawed vertebrates. However, correctly resolving the nature of the primitive vertebrate dentition is challenged by a dearth of evidence on dental development in primitive osteichthyans. Jaw elements from the Silurian-Devonian stem-osteichthyans Lophosteus and Andreolepis have been described to bear a dentition arranged in longitudinal rows and vertical files, reminiscent of a pattern of successional development. We tested this inference, using synchrotron radiation X-ray tomographic microscopy (SRXTM) to reveal the pattern of skeletal development preserved in the sclerochronology of the mineralized tissues. The tooth-like tubercles represent focal elaborations of dentine within otherwise continuous sheets of the dermal skeleton, present in at least three stacked generations. Thus, the tubercles are not discrete modular teeth and their arrangement into rows and files is a feature of the dermal ornamentation that does not reflect a polarity of development or linear succession. These fossil remains have no bearing on the nature of the dentition in osteichthyans and, indeed, our results raise questions concerning the homologies of these bones and the phylogenetic classification of Andreolepis and Lophosteus.

  3. Testing models of dental development in the earliest bony vertebrates, Andreolepis and Lophosteus

    PubMed Central

    Cunningham, John A.; Rücklin, Martin; Blom, Henning; Botella, Hector; Donoghue, Philip C. J.

    2012-01-01

    Theories on the development and evolution of teeth have long been biased by the fallacy that chondrichthyans reflect the ancestral condition for jawed vertebrates. However, correctly resolving the nature of the primitive vertebrate dentition is challenged by a dearth of evidence on dental development in primitive osteichthyans. Jaw elements from the Silurian–Devonian stem-osteichthyans Lophosteus and Andreolepis have been described to bear a dentition arranged in longitudinal rows and vertical files, reminiscent of a pattern of successional development. We tested this inference, using synchrotron radiation X-ray tomographic microscopy (SRXTM) to reveal the pattern of skeletal development preserved in the sclerochronology of the mineralized tissues. The tooth-like tubercles represent focal elaborations of dentine within otherwise continuous sheets of the dermal skeleton, present in at least three stacked generations. Thus, the tubercles are not discrete modular teeth and their arrangement into rows and files is a feature of the dermal ornamentation that does not reflect a polarity of development or linear succession. These fossil remains have no bearing on the nature of the dentition in osteichthyans and, indeed, our results raise questions concerning the homologies of these bones and the phylogenetic classification of Andreolepis and Lophosteus. PMID:22628098

  4. Climate and environmental effects of electric vehicles versus compressed natural gas vehicles in China: a life-cycle analysis at provincial level.

    PubMed

    Huo, Hong; Zhang, Qiang; Liu, Fei; He, Kebin

    2013-02-05

    Electric vehicles (EVs) and compressed natural gas vehicles (CNGVs), which are mainly coal-based and natural gas-based, are the two most widely proposed replacements of gasoline internal combustion engine vehicles (ICEVs) in P.R. China. We examine fuel-cycle emissions of greenhouse gases (GHGs), PM(2.5), PM(10), NO(x), and SO(2) of CNGVs and EVs relative to gasoline ICEVs and hybrids, by Chinese province. CNGVs can currently reduce emissions of GHGs, PM(10), PM(2,5), NO(x), and SO(2) by approximately 6%, 7%, 20%, 18% and 22%, respectively. EVs can reduce GHG emissions by 20%, but increase PM(10), PM(2.5), NO(x), and SO(2) emissions by approximately 360%, 250%, 120%, and 370%, respectively. Nevertheless, results vary significantly by province. Regarding their contribution to national emissions, PM increases from EVs are unimportant, because light-duty passenger vehicles contribute very little to overall PM emissions nationwide (≤0.05%); however, their NO(x) and SO(2) increases are important. Since China is striving to reduce power plant emissions, EVs are expected to have equivalent or even lower SO(2) and NO(x) emissions relative to ICEVs in the future (2030). Before then, however, EVs should be developed according to the cleanness of regional power mixes. This would lower their SO(2) and NO(x) emissions and earn more GHG reduction credits.

  5. Effect of Addition of Natural Antioxidants on the Shelf-Life of “Chorizo”, a Spanish Dry-Cured Sausage

    PubMed Central

    Pateiro, Mirian; Bermúdez, Roberto; Lorenzo, José Manuel; Franco, Daniel

    2015-01-01

    The dose effect of the addition of natural antioxidants (tea, chestnut, grape seed and beer extracts) on physicochemical, microbiological changes and on oxidative stability of dry-cured “chorizo”, as well as their effect during the storage under vacuum conditions was evaluated. Color parameters were significantly (p < 0.05) affected by the addition of antioxidants so that samples that contained antioxidants were more effective in maintaining color. The improving effects were dose-dependent with highest values with the dose of 50 mg/kg during ripening and depend on the extract during vacuum packaging. Addition of antioxidants decreased (p < 0.05) the oxidation, showing thiobarbituric acid reactive substances (TBARS) values below 0.4 mg MDA/kg. Natural antioxidants matched or even improved the results obtained for butylated hydroxytoluene (BHT). Regarding texture profile analysis (TPA) analysis, hardness values significantly (p < 0.001) decreased with the addition of antioxidants, obtaining the lower results with the dose of 200 mg/kg both during ripening and vacuum packaging. Antioxidants reduced the counts of total viable counts (TVC), lactic acid bacteria (LAB), mold and yeast. Free fatty acid content during ripening and under vacuum conditions showed a gradual and significant (p < 0.05) release as a result of lipolysis. At the end of ripening, the addition of GRA1000 protected chorizos from oxidative degradation. PMID:26785337

  6. Earliest Porotic Hyperostosis on a 1.5-Million-Year-Old Hominin, Olduvai Gorge, Tanzania

    PubMed Central

    Domínguez-Rodrigo, Manuel; Pickering, Travis Rayne; Diez-Martín, Fernando; Mabulla, Audax; Musiba, Charles; Trancho, Gonzalo; Baquedano, Enrique; Bunn, Henry T.; Barboni, Doris; Santonja, Manuel; Uribelarrea, David; Ashley, Gail M.; Martínez-Ávila, María del Sol; Barba, Rebeca; Gidna, Agness; Yravedra, José; Arriaza, Carmen

    2012-01-01

    Meat-eating was an important factor affecting early hominin brain expansion, social organization and geographic movement. Stone tool butchery marks on ungulate fossils in several African archaeological assemblages demonstrate a significant level of carnivory by Pleistocene hominins, but the discovery at Olduvai Gorge of a child's pathological cranial fragments indicates that some hominins probably experienced scarcity of animal foods during various stages of their life histories. The child's parietal fragments, excavated from 1.5-million-year-old sediments, show porotic hyperostosis, a pathology associated with anemia. Nutritional deficiencies, including anemia, are most common at weaning, when children lose passive immunity received through their mothers' milk. Our results suggest, alternatively, that (1) the developmentally disruptive potential of weaning reached far beyond sedentary Holocene food-producing societies and into the early Pleistocene, or that (2) a hominin mother's meat-deficient diet negatively altered the nutritional content of her breast milk to the extent that her nursing child ultimately died from malnourishment. Either way, this discovery highlights that by at least 1.5 million years ago early human physiology was already adapted to a diet that included the regular consumption of meat. PMID:23056303

  7. A caseian point for the evolution of a diaphragm homologue among the earliest synapsids.

    PubMed

    Lambertz, Markus; Shelton, Christen D; Spindler, Frederik; Perry, Steven F

    2016-12-01

    The origin of the diaphragm remains a poorly understood yet crucial step in the evolution of terrestrial vertebrates, as this unique structure serves as the main respiratory motor for mammals. Here, we analyze the paleobiology and the respiratory apparatus of one of the oldest lineages of mammal-like reptiles: the Caseidae. Combining quantitative bone histology and functional morphological and physiological modeling approaches, we deduce a scenario in which an auxiliary ventilatory structure was present in these early synapsids. Crucial to this hypothesis are indications that at least the phylogenetically advanced caseids might not have been primarily terrestrial but rather were bound to a predominantly aquatic life. Such a lifestyle would have resulted in severe constraints on their ventilatory system, which consequently would have had to cope with diving-related problems. Our modeling of breathing parameters revealed that these caseids were capable of only limited costal breathing and, if aquatic, must have employed some auxiliary ventilatory mechanism to quickly meet their oxygen demand upon surfacing. Given caseids' phylogenetic position at the base of Synapsida and under this aquatic scenario, it would be most parsimonious to assume that a homologue of the mammalian diaphragm had already evolved about 50 Ma earlier than previously assumed.

  8. It's a long way from amphioxus: descendants of the earliest chordate.

    PubMed

    Garcia-Fernàndez, Jordi; Benito-Gutiérrez, Elia

    2009-06-01

    The origin of chordates and the consequent genesis of vertebrates were major events in natural history. The amphioxus (lancelet) is now recognised as the closest extant relative to the stem chordate and is the only living invertebrate that retains a vertebrate-like development and body plan through its lifespan, despite more than 500 million years of independent evolution from the stem vertebrate. The inspiring data coming from its recently sequenced genome confirms that amphioxus has a prototypical chordate genome with respect to gene content and structure, and even chromosomal organisation. Pushed by joint efforts of amphioxus researchers, amphioxus is now entering a new era, namely its maturation as a laboratory model, through the availability of a large amount of molecular data and the advent of experimental manipulation of the embryo. These two facts may well serve to illuminate the hidden secrets of the genetic changes that generated, among other vertebrates, ourselves.

  9. Neutron activation of natural materials in a PWR spectrum: feedback on {sup 116m}In relative γ emission intensities and half-life

    SciTech Connect

    Gruel, Adrien; Geslot, Benoit; Di Salvo, Jacques; Blaise, Patrick; Girard, Jean-Michel; Destouches, Christophe

    2015-07-01

    During the MAESTRO program, carried out between 2011 and 2014 in MINERVE zero power reactor, common Gen-II and Gen-III light water reactor materials were irradiated. For some of these materials, the decay of their activation products was also measured by γ spectrometry. Initially devoted to the measurement of the integral capture cross section by activation and reactivity-oscillation method, these results can also provide useful information on decay data of various radionuclides. This approach of this experiment led to a common roadmap shared by the Experimental Physics Section and the Henri Becquerel National Laboratory to improve decay data in nuclear data libraries. Results discussed in this paper concern the relative emission intensities of the main γ rays of {sup 116m}In. Six irradiations of samples with various physical forms of {sup nat}In were carried out. Measurements were analyzed using decay data from several evaluations and it is shown that γ ray activities are not consistent. Analyses were carried out to provide new relative γ emission intensities from these measurements. The {sup 116m}In half-life has also been measured and shows a good agreement with existing values. Finally, an overview of the foreseen results on additional decay data from the MAESTRO program is given. (authors)

  10. Efficacy of mint (Mentha arvensis) leaf and citrus (Citrus aurantium) peel extracts as natural preservatives for shelf life extension of chill stored Indian mackerel.

    PubMed

    Viji, Pankyamma; Binsi, Puthanpurakkal Kizhakkathil; Visnuvinayagam, Sivam; Bindu, Jaganath; Ravishankar, Chandragiri Nagarajarao; Srinivasa Gopal, Teralandur Krishnaswamy

    2015-10-01

    Efficacy of mint (Mentha arvensis) leaf and citrus (Citrus aurantium) peel extracts in retarding the quality changes in Indian mackerel during chilled storage was investigated. Mint leaf extract showed higher quantity of phenolics and superior in-vitro antioxidant activities than citrus peel extract. Gutted mackerel were given a dip treatment in mint extract (0.5 %, w/v) and citrus extract (1 % w/v), packed in LDPE pouches and stored at 0-2 °C. The biochemical quality indices viz. total volatile base nitrogen (TVB-N), trimethylamine nitrogen (TMA-N), free fattyacids (FFA) were significantly (p < 0.05) lower in mint extract (ME) treated fishes compared to citrus extract (CE) treated and control fishes (C) without any treatment. Plant extract treatment significantly inhibited lipid oxidation in mackerel as indicated by peroxide value (PV) and thiobarbituric acid reactive substances (TBARS). Aerobic plate count (APC) was markedly higher in C group followed by CE group throughout the storage period. As per sensory evaluation, shelf life of Indian mackerel was determined to be 11-13 days for C group, 13-15 days for CE group and 16-17 days for ME group, during storage at 0-2 °C.

  11. Use of natural antimicrobials to improve the quality characteristics of fresh "Phyllo" - A dough-based wheat product - Shelf life assessment.

    PubMed

    Tsiraki, Maria I; Karam, Layal; Abiad, Mohamad G; Yehia, Hany M; Savvaidis, Ioannis N

    2017-04-01

    This study explores the effects of chitosan and natamycin on the quality of fresh "Phyllo" - a dough-based wheat product, by monitoring the microbiological, physicochemical and sensory parameters. Four different lots of phyllo samples stored under aerobic packaging conditions, in the absence or presence of the aforementioned antimicrobials, were prepared and stored at 4 °C. Microbiological data suggested that, the combination of chitosan and natamycin resulted in significant reductions (1-3 log cfu/g) of the microbial species examined (mesophilic total viable counts; TVC), yeasts/molds, psychrotrophic and lactic acid bacteria (LAB), Enterobacteriaceae and coliforms) by day 10. The pH values of treated phyllo samples were lower on final day 10, as compared to the untreated phyllo, and of the Hunter color parameters (L*, b* and a*) that were evaluated, mostly the combined treatment of chitosan and natamycin maintained the original lightness (L*) and color (yellowness) stability (b*) of phyllo product during the storage period. Sensory data, based on overall acceptability (mean values of appearance and odor) scores confirmed the superiority of combined treatment of chitosan and natamycin, resulting in almost a doubling of the shelf-life of fresh phyllo, while retaining excellent sensorial characteristics (appearance and odor) even on final storage day (10).

  12. Glycine Identification in Natural Jarosites Using Laser-Desorption Fourier Transform Mass Spectrometry: Implications for the search for life on Mars

    SciTech Connect

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

    2008-04-01

    The jarosite group minerals have received increasing attention since the discovery of jarosite by the Mars Exploration Rover-Opportunity on the Martian surface. The mineral group has the ability to incorporate foreign ions in its structure leading to investigations regarding its use as an indicator of aqueous and/or biological activity 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 worldwide locations. One of the organic cluster ions has been attributed to glycine based on results from combinations of glycine with synthetic jarosite and K2SO4. The ability to observe these organic signatures in jarosite samples with an “in situ” instrumental technique, such as 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.

  13. The earliest sense of self and others: Merleau-Ponty and recent developmental studies.

    PubMed

    Gallagher, Shaun; Meltzoff, Andrew N

    1996-03-01

    Recent studies in developmental psychology have found evidence to suggest that there exists an innate system that accounts for the possibilities of early infant imitation and the existence of phantom limbs in cases of congenital absence of limbs. These results challenge traditional assumptions about the status and development of the body schema and body image, and about the nature of the translation process between perceptual experience and motor ability. Merleau-Ponty, who was greatly influenced by his study of developmental psychology, and whose phenomenology of perception was closely tied to the concept of the body schema, accepted these traditional assumptions. They also informed his philosophical conclusions concerning the experience of self and others. We re-examine issues involved in understanding self and others in light of the more recent research in developmental psychology. More specifically our re-examination challenges a number of Merleau-Ponty's conclusions and suggests, in contrast, that the newborn infant is capable of a rudimentary differentiation between self and non-self.

  14. Earliest domestication of common millet (Panicum miliaceum) in East Asia extended to 10,000 years ago

    PubMed Central

    Lu, Houyuan; Zhang, Jianping; Liu, Kam-biu; Wu, Naiqin; Li, Yumei; Zhou, Kunshu; Ye, Maolin; Zhang, Tianyu; Zhang, Haijiang; Yang, Xiaoyan; Shen, Licheng; Xu, Deke; Li, Quan

    2009-01-01

    The origin of millet from Neolithic China has generally been accepted, but it remains unknown whether common millet (Panicum miliaceum) or foxtail millet (Setaria italica) was the first species domesticated. Nor do we know the timing of their domestication and their routes of dispersal. Here, we report the discovery of husk phytoliths and biomolecular components identifiable solely as common millet from newly excavated storage pits at the Neolithic Cishan site, China, dated to between ca. 10,300 and ca. 8,700 calibrated years before present (cal yr BP). After ca. 8,700 cal yr BP, the grain crops began to contain a small quantity of foxtail millet. Our research reveals that the common millet was the earliest dry farming crop in East Asia, which is probably attributed to its excellent resistance to drought. PMID:19383791

  15. A new genus and species of micro bee fly from the Earliest Eocene French amber (Diptera: Mythicomyiidae: Psiloderoidinae).

    PubMed

    Myskowiak, Justine; Garrouste, Romain; Nel, Andre

    2016-05-26

    Mythicomyiidae, or micro bee flies, are tiny flies (0.5-5.0 mm) that are found throughout most parts of the world except the highest altitudes and latitudes (Greathead & Evenhuis 2001). Including all extinct and extant taxa, the Mythicomyiidae currently comprise more than 380 valid taxonomic species distributed among 30 genera. The subfamily Psiloderoidinae is especially well represented among the fossil Mythicomyiidae by seven Cretaceous or Cenozoic genera. We here describe a new genus and a new species of this subfamily based on fossils from the Earliest Eocene of Oise (France). A Psiloderoidinae, Proplatypygus matilei Nel & DePloëg, 2004, is already described in this amber. Another mythicomyiid, Eurodoliopteryx inexpectatus Nel, 2006, is the most frequent bombylioid in this amber (Nel & DePloëg, 2004; Nel, 2006).

  16. The earliest archaeological maize (Zea mays L.) from highland Mexico: new accelerator mass spectrometry dates and their implications.

    PubMed

    Piperno, D R; Flannery, K V

    2001-02-13

    Accelerator mass spectrometry age determinations of maize cobs (Zea mays L.) from Guilá Naquitz Cave in Oaxaca, Mexico, produced dates of 5,400 carbon-14 years before the present (about 6,250 calendar years ago), making those cobs the oldest in the Americas. Macrofossils and phytoliths characteristic of wild and domesticated Zea fruits are absent from older strata from the site, although Zea pollen has previously been identified from those levels. These results, together with the modern geographical distribution of wild Zea mays, suggest that the cultural practices that led to Zea domestication probably occurred elsewhere in Mexico. Guilá Naquitz Cave has now yielded the earliest macrofossil evidence for the domestication of two major American crop plants, squash (Cucurbita pepo) and maize.

  17. Earliest human occupations at Dmanisi (Georgian Caucasus) dated to 1.85–1.78 Ma

    PubMed Central

    Ferring, Reid; Oms, Oriol; Agustí, Jordi; Berna, Francesco; Nioradze, Medea; Shelia, Teona; Tappen, Martha; Vekua, Abesalom; Zhvania, David; Lordkipanidze, David

    2011-01-01

    The early Pleistocene colonization of temperate Eurasia by Homo erectus was not only a significant biogeographic event but also a major evolutionary threshold. Dmanisi's rich collection of hominin fossils, revealing a population that was small-brained with both primitive and derived skeletal traits, has been dated to the earliest Upper Matuyama chron (ca. 1.77 Ma). Here we present archaeological and geologic evidence that push back Dmanisi's first occupations to shortly after 1.85 Ma and document repeated use of the site over the last half of the Olduvai subchron, 1.85–1.78 Ma. These discoveries show that the southern Caucasus was occupied repeatedly before Dmanisi's hominin fossil assemblage accumulated, strengthening the probability that this was part of a core area for the colonization of Eurasia. The secure age for Dmanisi's first occupations reveals that Eurasia was probably occupied before Homo erectus appears in the East African fossil record. PMID:21646521

  18. Influence of the binder nature on the performance and cycle life of activated carbon electrodes in electrolytes containing Li-salt

    NASA Astrophysics Data System (ADS)

    Tran, Hai Yen; Wohlfahrt-Mehrens, Margret; Dsoke, Sonia

    2017-02-01

    In the current work, the influence of the binder nature on the mechanical and electrochemical stability of activated carbon (AC) electrodes in LiPF6/EC/DMC is shown. Different binders employing water-based preparation route, i.e. poly(acrylic acid), sodium polyacrylate and sodium alginate, are evaluated and compared with the fluorinated binders (i.e. polytetrafluoroethylene, PTFE and polyvinylidene difluoride, PVDF). Results obtained during the investigation show that the rheological behavior of the slurry as well as the electrode porosity can be significantly affected by choice of binder. More precisely, slurries containing AC and alginate can experience the stress relaxation test without breaking down the polymer network due to the multiple bonds between AC surface and the carboxylic group of the pyranose ring of α-L-guluronic acid of the sodium alginate. Moreover, the AC-Alginate electrodes can sustain up to 20 000 cycles (∼902 h) at I = 1.39 A g-1 in LiPF6 without a great increase in total equivalent series resistance (ESR) (ESRAC - Alginate ,20000th cycle = 4 × ESR1st cycle ,while ESRAC - PVDF ,20000th cycle = 6.5 × ESR1st cycle) . The electrochemical impedance spectroscopy analysis on the aged electrodes shows that AC-Alginate can offer sufficient accessible porosity for extended charge/discharge cycles.

  19. The nature and timing of specific copy number changes in the course of molecular progression in diffuse gliomas: further elucidation of their genetic "life story".

    PubMed

    Jeuken, Judith W M; Sijben, Angelique; Bleeker, Fonnet E; Boots-Sprenger, Sandra H E; Rijntjes, Jos; Gijtenbeek, Johanna M M; Mueller, Wolf; Wesseling, Pieter

    2011-05-01

    Up till now, typing and grading of diffuse gliomas is based on histopathological features. However, more objective tools are needed to improve reliable assessment of their biological behavior. We evaluated 331 diffuse gliomas for copy number changes involving 1p, 19q, CDKN2A, PTEN and EGFR(vIII) by Multiplex Ligation-dependent Probe Amplification (MLPA®, Amsterdam, The Netherlands). Specifically based on the co-occurrence of these aberrations we built a model for the timing of the different events and their exact nature (hemi- → homozygous loss; low-level gain → (high-copy) amplification) in the course of molecular progression. The mutation status of IDH1 and TP53 was also evaluated and shown to correlate with the level of molecular progression. The relevance of the proposed model was confirmed by analysis of 36 sets of gliomas and their 39 recurrence(s) whereas survival analysis for anaplastic gliomas confirmed the actual prognostic relevance of detecting molecular malignancy. Moreover, based on our results, molecular diagnostic analysis of 1p/19q can be further improved as different aberrations were identified, some of them being indicative for advanced molecular malignancy rather than for favorable tumor behavior. In conclusion, identification of molecular malignancy as proposed will aid in establishing a risk profile for individual patients and thereby in therapeutic decision making.

  20. Elevation of Intact and Proteolytic Fragments of Acute Phase Proteins Constitutes the Earliest Systemic Antiviral Response in HIV-1 Infection

    PubMed Central

    Kramer, Holger B.; Lavender, Kerry J.; Qin, Li; Stacey, Andrea R.; Liu, Michael K. P.; di Gleria, Katalin; Simmons, Alison; Gasper-Smith, Nancy; Haynes, Barton F.; McMichael, Andrew J.; Borrow, Persephone; Kessler, Benedikt M.

    2010-01-01

    The earliest immune responses activated in acute human immunodeficiency virus type 1 infection (AHI) exert a critical influence on subsequent virus spread or containment. During this time frame, components of the innate immune system such as macrophages and DCs, NK cells, β-defensins, complement and other anti-microbial factors, which have all been implicated in modulating HIV infection, may play particularly important roles. A proteomics-based screen was performed on a cohort from whom samples were available at time points prior to the earliest positive HIV detection. The ability of selected factors found to be elevated in the plasma during AHI to inhibit HIV-1 replication was analyzed using in vitro PBMC and DC infection models. Analysis of unique plasma donor panels spanning the eclipse and viral expansion phases revealed very early alterations in plasma proteins in AHI. Induction of acute phase protein serum amyloid A (A-SAA) occurred as early as 5–7 days prior to the first detection of plasma viral RNA, considerably prior to any elevation in systemic cytokine levels. Furthermore, a proteolytic fragment of alpha–1-antitrypsin (AAT), termed virus inhibitory peptide (VIRIP), was observed in plasma coincident with viremia. Both A-SAA and VIRIP have anti-viral activity in vitro and quantitation of their plasma levels indicated that circulating concentrations are likely to be within the range of their inhibitory activity. Our results provide evidence for a first wave of host anti-viral defense occurring in the eclipse phase of AHI prior to systemic activation of other immune responses. Insights gained into the mechanism of action of acute-phase reactants and other innate molecules against HIV and how they are induced could be exploited for the future development of more efficient prophylactic vaccine strategies. PMID:20463814

  1. Opportunistic Feeding Strategy for the Earliest Old World Hypsodont Equids: Evidence from Stable Isotope and Dental Wear Proxies

    PubMed Central

    Tütken, Thomas; Kaiser, Thomas M.; Vennemann, Torsten; Merceron, Gildas

    2013-01-01

    Background The equid Hippotherium primigenium, with moderately hypsodont cheek teeth, rapidly dispersed through Eurasia in the early late Miocene. This dispersal of hipparions into the Old World represents a major faunal event during the Neogene. The reasons for this fast dispersal of H. primigenium within Europe are still unclear. Based on its hypsodonty, a high specialization in grazing is assumed although the feeding ecology of the earliest European hipparionines within a pure C3 plant ecosystem remains to be investigated. Methodology/Principal Findings A multi-proxy approach, combining carbon and oxygen isotopes from enamel as well as dental meso- and microwear analyses of cheek teeth, was used to characterize the diet of the earliest European H. primigenium populations from four early Late Miocene localities in Germany (Eppelsheim, Höwenegg), Switzerland (Charmoille), and France (Soblay). Enamel δ13C values indicate a pure C3 plant diet with small (<1.4‰) seasonal variations for all four H. primigenium populations. Dental wear and carbon isotope compositions are compatible with dietary differences. Except for the Höwenegg hipparionines, dental microwear data indicate a browse-dominated diet. By contrast, the tooth mesowear patterns of all populations range from low to high abrasion suggesting a wide spectrum of food resources. Conclusions/Significance Combined dental wear and stable isotope analysis enables refined palaeodietary reconstructions in C3 ecosystems. Different H. primigenium populations in Europe had a large spectrum of feeding habits with a high browsing component. The combination of specialized phenotypes such as hypsodont cheek teeth with a wide spectrum of diet illustrates a new example of the Liem’s paradox. This dietary flexibility associated with the capability to exploit abrasive food such as grasses probably contributed to the rapid dispersal of hipparionines from North America into Eurasia and the fast replacement of the brachydont

  2. Sequences, stratigraphy and scenarios: what can we say about the fossil record of the earliest tetrapods?

    PubMed Central

    Friedman, Matt; Brazeau, Martin D.

    2011-01-01

    Past research on the emergence of digit-bearing tetrapods has led to the widely accepted premise that this important evolutionary event occurred during the Late Devonian. The discovery of convincing digit-bearing tetrapod trackways of early Middle Devonian age in Poland has upset this orthodoxy, indicating that current scenarios which link the timing of the origin of digited tetrapods to specific events in Earth history are likely to be in error. Inspired by this find, we examine the fossil record of early digit-bearing tetrapods and their closest fish-like relatives from a statistical standpoint. We find that the Polish trackways force a substantial reconsideration of the nature of the early tetrapod record when only body fossils are considered. However, the effect is less drastic (and often not statistically significant) when other reliably dated trackways that were previously considered anachronistic are taken into account. Using two approaches, we find that 95 per cent credible and confidence intervals for the origin of digit-bearing tetrapods extend into the Early Devonian and beyond, spanning late Emsian to mid Ludlow. For biologically realistic diversity models, estimated genus-level preservation rates for Devonian digited tetrapods and their relatives range from 0.025 to 0.073 per lineage-million years, an order of magnitude lower than species-level rates for groups typically considered to have dense records. Available fossils of early digited tetrapods and their immediate relatives are adequate for documenting large-scale patterns of character acquisition associated with the origin of terrestriality, but low preservation rates coupled with clear geographical and stratigraphic sampling biases caution against building scenarios for the origin of digits and terrestrialization tied to the provenance of particular specimens or faunas. PMID:20739322

  3. Why Is Nature Beneficial?: The Role of Connectedness to Nature

    ERIC Educational Resources Information Center

    Mayer, F. Stephan; Frants, Cynthia McPherson; Bruehlman-Senecal, Emma; Dolliver, Kyffin

    2009-01-01

    Three studies examine the effects of exposure to nature on positive affect and ability to reflect on a life problem. Participants spent 15 min walking in a natural setting (Studies 1, 2, & 3), an urban setting (Study 1), or watching videos of natural and urban settings (Studies 2 & 3). In all three studies, exposure to nature increased…

  4. Breaking News: Decoding the earliest "computer": The antikythera astrolabe. Science and technology in ancient Greece

    NASA Astrophysics Data System (ADS)

    Liritzis, I.

    Center for History and Palaeography, Cultural Foundation of the National Bank of Greece, X-Tek Systems, and Hewlett-Packard. They applied a powerful microfocus X-ray computer assisted tomography (CAT) using reflectance imaging to enhance surface details. The first results were announced in this week issue of the international scientific journal of Nature and at the same time during the 2-day international conference (30th Nov to 1st Dec.,in Athens) where the present information is retrieved from (Deconding the Antikythera Mechnism, Abstract Book). The results are indeed exciting and enabled new detailed 3D reconstruction of the internal structure of the Antikythera Mechanism using a total of one terabyte of CAT data and the surface polynomial mapping images.

  5. WOWBugs: New Life for Life Science.

    ERIC Educational Resources Information Center

    Matthews, Robert W.; And Others

    This book of life science activities introduces a new experimental animal--the WOWBug, "Melittobia digitata"--that is commonly found in nature but has never before been used in the precollege classroom. It includes 20 activities and experiments for grades 5-12, that cover topics from basic orientation to ecological interactions, from physical…

  6. Nature's Advice Book

    ERIC Educational Resources Information Center

    Mahlin, Kathryn; Robertson, Amy

    2005-01-01

    What do can people learn from the world around them? Can a tree really teach something about life? Many times teachers provide students with facts about nature but fail to consider what one can learn from the natural world around them. After many months of exploring various ecosystems such as the prairie, rain forest, and desert, one of the…

  7. Investigations into the Early Life-history of Naturally Produced Spring Chinook Salmon and Summer Steelhead in the Grande Ronde River Basin, Annual Report 2001.

    SciTech Connect

    Reischauer, Alyssa; Monzyk, Frederick; Van Dyke, Erick

    2003-06-01

    We determined migration timing and abundance of juvenile spring chinook salmon Oncorhynchus tshawytscha and juvenile steelhead/rainbow trout Oncorhynchus mykiss using rotary screw traps on four streams in the Grande Ronde River basin during the 2001 migratory year (MY 2001) from 1 July 2000 through 30 June 2001. Based on migration timing and abundance, two distinct life-history strategies of juvenile spring chinook and O. mykiss could be distinguished. An 'early' migrant group left upper rearing areas from 1 July 2000 through 29 January 2001 with a peak in the fall. A 'late' migrant group descended from upper rearing areas from 30 January 2001 through 30 June 2001 with a peak in the spring. The migrant population of juvenile spring chinook salmon in the upper Grande Ronde River in MY 2001 was very low in comparison to previous migratory years. We estimated 51 juvenile spring chinook migrated out of upper rearing areas with approximately 12% of the migrant population leaving as early migrants to overwinter downstream. In the same migratory year, we estimated 16,067 O. mykiss migrants left upper rearing areas with approximately 4% of these fish descending the upper Grande Ronde River as early migrants. At the Catherine Creek trap, we estimated 21,937 juvenile spring chinook migrants in MY 2001. Of these migrants, 87% left upper rearing areas early to overwinter downstream. We also estimated 20,586 O. mykiss migrants in Catherine Creek with 44% leaving upper rearing areas early to overwinter downstream. At the Lostine River trap, we estimated 13,610 juvenile spring chinook migrated out of upper rearing areas with approximately 77% migrating early. We estimated 16,690 O. mykiss migrated out of the Lostine River with approximately 46% descending the river as early migrants. At the Minam River trap, we estimated 28,209 juvenile spring chinook migrated out of the river with 36% migrating early. During the same period, we estimated 28,113 O. mykiss with approximately 14

  8. LIFE: Life Investigation For Enceladus A Sample Return Mission Concept in Search for Evidence of Life.

    PubMed

    Tsou, Peter; Brownlee, Donald E; McKay, Christopher P; Anbar, Ariel D; Yano, Hajime; Altwegg, Kathrin; Beegle, Luther W; Dissly, Richard; Strange, Nathan J; Kanik, Isik

    2012-08-01

    Life Investigation For Enceladus (LIFE) presents a low-cost sample return mission to Enceladus, a body with high astrobiological potential. There is ample evidence that liquid water exists under ice coverage in the form of active geysers in the "tiger stripes" area of the southern Enceladus hemisphere. This active plume consists of gas and ice particles and enables the sampling of fresh materials from the interior that may originate from a liquid water source. The particles consist mostly of water ice and are 1-10 μ in diameter. The plume composition shows H(2)O, CO(2), CH(4), NH(3), Ar, and evidence that more complex organic species might be present. Since life on Earth exists whenever liquid water, organics, and energy coexist, understanding the chemical components of the emanating ice particles could indicate whether life is potentially present on Enceladus. The icy worlds of the outer planets are testing grounds for some of the theories for the origin of life on Earth. The LIFE mission concept is envisioned in two parts: first, to orbit Saturn (in order to achieve lower sampling speeds, approaching 2 km/s, and thus enable a softer sample collection impact than Stardust, and to make possible multiple flybys of Enceladus); second, to sample Enceladus' plume, the E ring of Saturn, and the Titan upper atmosphere. With new findings from these samples, NASA could provide detailed chemical and isotopic and, potentially, biological compositional context of the plume. Since the duration of the Enceladus plume is unpredictable, it is imperative that these samples are captured at the earliest flight opportunity. If LIFE is launched before 2019, it could take advantage of a Jupiter gravity assist, which would thus reduce mission lifetimes and launch vehicle costs. The LIFE concept offers science returns comparable to those of a Flagship mission but at the measurably lower sample return costs of a Discovery-class mission.

  9. Occupational Outlook in the 15th Century: Sanchez de Arevalo's Mirror of Human Life.

    ERIC Educational Resources Information Center

    Chabassus, Henri; Zytowski, Donald G.

    1987-01-01

    Discusses a book published in 1468, Rodrigo Sanchez de Arevalo's "Mirror of Human Life," the earliest known comprehensive compilation of occupational descriptions. Describes the similarity of Sanchez's ideas about occupational choice and contemporary career counseling theory: informed choice; person-environment congruence; and the components of…

  10. Astronomers Unveiling Life's Cosmic Origins

    NASA Astrophysics Data System (ADS)

    2009-02-01

    Processes that laid the foundation for life on Earth -- star and planet formation and the production of complex organic molecules in interstellar space -- are yielding their secrets to astronomers armed with powerful new research tools, and even better tools soon will be available. Astronomers described three important developments at a symposium on the "Cosmic Cradle of Life" at the annual meeting of the American Association for the Advancement of Science in Chicago, IL. Chemistry Cycle The Cosmic Chemistry Cycle CREDIT: Bill Saxton, NRAO/AUI/NSF Full Size Image Files Chemical Cycle Graphic (above image, JPEG, 129K) Graphic With Text Blocks (JPEG, 165K) High-Res TIFF (44.2M) High-Res TIFF With Text Blocks (44.2M) In one development, a team of astrochemists released a major new resource for seeking complex interstellar molecules that are the precursors to life. The chemical data released by Anthony Remijan of the National Radio Astronomy Observatory (NRAO) and his university colleagues is part of the Prebiotic Interstellar Molecule Survey, or PRIMOS, a project studying a star-forming region near the center of our Milky Way Galaxy. PRIMOS is an effort of the National Science Foundation's Center for Chemistry of the Universe, started at the University of Virginia (UVa) in October 2008, and led by UVa Professor Brooks H. Pate. The data, produced by the NSF's Robert C. Byrd Green Bank Telescope (GBT) in West Virginia, came from more than 45 individual observations totalling more than nine GigaBytes of data and over 1.4 million individual frequency channels. Scientists can search the GBT data for specific radio frequencies, called spectral lines -- telltale "fingerprints" -- naturally emitted by molecules in interstellar space. "We've identified more than 720 spectral lines in this collection, and about 240 of those are from unknown molecules," Remijan said. He added, "We're making available to all scientists the best collection of data below 50 GHz ever produced for

  11. Comparisons of Mineralogy of Lunar Meteorites Possibly from the Farside and the Kaguya Remote Sensing Data to Reconstruct the Earliest Anorthositic Crust of the Moon

    NASA Astrophysics Data System (ADS)

    Takeda, H.; Nagaoka, H.; Ohtake, M.; Kobayashi, S.; Yamaguchi, A.; Morota, T.; Karouji, Y.; Haruyma, J.; Katou, M.; Hiroi, T.; Nyquist, L. E.

    2012-03-01

    Comparisons of mineralogy of lunar meteorites (Dhofar 911, etc.) from the farside and the Kaguya Th concentrations a to reconstruct the earliest, asymmetric anorthositic crust of the Moon. We propose that these meteorites might have come from the Dirichlet-Jackson basin.

  12. The Earliest Reference to ADHD in the Medical Literature? Melchior Adam Weikard's Description in 1775 of "Attention Deficit" (Mangel der Aufmerksamkeit, Attentio Volubilis)

    ERIC Educational Resources Information Center

    Barkley, Russell A.; Peters, Helmut

    2012-01-01

    Objective: The present article reports on the discovery and translation of a chapter in a 1775 medical textbook by the German physician, Melchior Adam Weikard, which describes attention disorders. This article is believed to be the earliest reference to the syndrome that today is known as attention deficit hyperactivity disorder, or ADHD. Method:…

  13. Serpentinization as a source of energy at the origin of life.

    PubMed

    Russell, M J; Hall, A J; Martin, W

    2010-12-01

    For life to have emerged from CO₂, rocks, and water on the early Earth, a sustained source of chemically transducible energy was essential. The serpentinization process is emerging as an increasingly likely source of that energy. Serpentinization of ultramafic crust would have continuously supplied hydrogen, methane, minor formate, and ammonia, as well as calcium and traces of acetate, molybdenum and tungsten, to off-ridge alkaline hydrothermal springs that interfaced with the metal-rich carbonic Hadean Ocean. Silica and bisulfide were also delivered to these springs where cherts and sulfides were intersected by the alkaline solutions. The proton and redox gradients so generated represent a rich source of naturally produced chemiosmotic energy, stemming from geochemistry that merely had to be tapped, rather than induced, by the earliest biochemical systems. Hydrothermal mounds accumulating at similar sites in today's oceans offer conceptual and experimental models for the chemistry germane to the emergence of life, although the ubiquity of microbial communities at such sites in addition to our oxygenated atmosphere preclude an exact analogy.

  14. Is sleep's 'supreme mystery' unraveling? An evolutionary analysis of sleep encounters no mystery; nor does life's earliest sleep, recently discovered in jellyfish.

    PubMed

    Kavanau, J Lee

    2006-01-01

    Biotelemetry has revealed daily 15-h behavioral sleep periods in a cubomedusan jellyfish, Chironex fleckeri. Its sleep is expected to be phylogenetically most primitive, since jellyfish possess only two germ layers. They belong to the phylum Cnidaria, the 'simplest' multicellular organisms with an organized nervous system. Cubomedusae have a complex visual system with 24 eyes of four different types, each type specialized for a different task. Input to these eyes during visually guided fast-swimming predation requires enormous amounts of neural processing, possibly nearly saturating the capacity of their comparatively simple nervous system. These heavy neural demands may account for the need for fifteen hours of sleep. C. fleckeri is the only animal known for which sleep may be either present or absent, dependent on lifestyle. Limited knowledge of behavior of some other cubomedusae suggests that they also possess this faculty. The finding of sleep in C. fleckeri supports current proposals of sleep's origin and basic function. Evolutionary analyses link sleep to a conflict produced by excessive processing demands on multifunctional neural circuitry for detailed focal vision by complex lensed eyes. The conflict arises between the enormous demands of complex visual analysis and needs for split-second control of actions, on the one hand, and non-urgent processing of memories of ongoing and stored events, on the other. Conflict is resolved by deferring the non-urgent processing to periods of sleep. Without sleep, selection would favor the evolution of circuitry 'dedicated' to single or but few tasks, with corresponding lesser efficiency. Had complex lensed eyes of medusae originated as a consequence of selection for increased mating success of males pursuing females, it could have occurred before the evolution of fast-swimming bilateral (three-germ-layered) prey. But if it was a consequence of selection for increased prey-hunting success, the origin of such eyes probably awaited the coexistence of bilateral prey.

  15. Identification of the earliest collagen- and plant-based coatings from Neolithic artefacts (Nahal Hemar cave, Israel)

    PubMed Central

    Solazzo, Caroline; Courel, Blandine; Connan, Jacques; van Dongen, Bart E.; Barden, Holly; Penkman, Kirsty; Taylor, Sheila; Demarchi, Beatrice; Adam, Pierre; Schaeffer, Philippe; Nissenbaum, Arie; Bar-Yosef, Ofer; Buckley, Michael

    2016-01-01

    Mortuary practices in human evolution record cognitive, social changes and technological innovations. The Neolithic Revolution in the Levant was a watershed in this domain that has long fascinated the archaeological community. Plaster modelled skulls are well known at Jericho and several other Neolithic sites, and in Nahal Hemar cave (Israel, ca. 8200 −7300 cal. BC) excavations yielded six unique human skulls covered with a black organic coating applied in a net pattern evoking a headdress. This small cave was used as storage for paraphernalia in the semi-arid area of the Judean desert and the dry conditions preserved other artefacts such as baskets coated with a similar dark substance. While previous analysis had revealed the presence of amino acids consistent with a collagen signature, in the present report, specific biomarkers were characterised using combined proteomic and lipid approaches. Basket samples yielded collagen and blood proteins of bovine origin (Bos genus) and a large sequence coverage of a plant protein charybdin (Charybdis genus). The skull residue samples were dominated by benzoate and cinnamate derivatives and triterpenes consistent with a styrax-type resin (Styrax officinalis), thus providing the earliest known evidence of an odoriferous plant resin used in combination with an animal product. PMID:27503740

  16. Iapetonudus (N. gen.) and Iapetognathus Landing, unusual Earliest Ordovician multielement conodont taxa and their utility for biostratigraphy

    USGS Publications Warehouse

    Nicoll, R.S.; Miller, J.F.; Nowlan, G.S.; Repetski, J.E.; Ethington, Raymond L.

    1999-01-01

    The Early Ordovician (Tremadocian) multielement conodont genus Iapetognathus is one of the oldest denticulate euconodont genera known. The ramiform-ramiform apparatus structure of Iapetognathus is not similar morphologically to other Late Cambrian to Earliest Ordovician denticulate multielement taxa, such as Eodentatus or Cordyloduts, because the major denticulate process has a lateral rather than a posterior orientation as it is in the other two examples. For this reason the genus is believed to have developed from the coniform-coniform apparatus Iapetonudus ibexensis (N.gen., n.sp.) through the development of the denticulate lateral processes. The two genera have a number of morphologic features in common and appear in stratigraphic succession. Iapetognathus aengensis (Lindstro??m) is redefined as a multielement taxon using topotype material and Ig. preaengensis Landing is placed in synonymy with it. Iapetognathus sprakersi, recently described by Landing in Landing and others (1996), is recognized as a multielement species and the new multielement species, Ig. fluctivagus, Ig. jilinensis and Ig. landingi n. spp. are described herein, based on type specimens from Utah (U.S.A.), Jilin (China) and Colorado (U.S.A.) respectively. Iapetonudus and Iapetognathus are important genera in defining the level of the Cambrian-Ordovician boundary. Iapetonudus is currently recognized only from Utah, Texas and Oklahoma, but Iapetognathus is cosmopolitan in its distribution.

  17. Stable isotope paleoclimatology of the earliest Eocene using kimberlite-hosted mummified wood from the Canadian Subarctic

    NASA Astrophysics Data System (ADS)

    Hook, B. A.; Halfar, J.; Gedalof, Z.; Bollmann, J.; Schulze, D.

    2014-11-01

    The recent discovery of well-preserved mummified wood buried within a subarctic kimberlite diamond mine prompted a paleoclimatic study of the early Eocene "hothouse" (ca. 53.3 Ma). At the time of kimberlite eruption, the Subarctic and Artic were warm and humid producing a temperate rainforest biome well north of the Arctic Circle. Previous studies have estimated mean annual temperatures in this region were 4-20 °C in the early Eocene, using a variety of proxies including leaf margin analysis, and stable isotopes (δ18O) of fossil cellulose. Here, we examine stable isotopes of tree-ring cellulose at subannual to annual scale resolution, using the oldest viable cellulose found to date. We use mechanistic models and transfer functions to estimate earliest Eocene temperatures using mummified cellulose, which was well preserved in the kimberlite. Multiple samples of Piceoxylon wood within the kimberlite were crossdated by tree-ring width. Multiple proxies are used in combination to tease apart likely environmental factors influencing the tree physiology and growth in the unique extinct ecosystem of the Polar rainforest. Calculations of interannual variation in temperature over a multidecadal time-slice in the early Eocene are presented, with a mean temperature estimate of 11.4 °C (1σ = 1.8 °C) based on δ18O. Dual-isotope spectral analysis suggests that multidecadal climate cycles similar to the modern Pacific Decadal Oscillation likely drove temperature and cloudiness trends on 20-30 year timescales.

  18. Earliest effects of sudden occlusions on pressure profiles in selected locations of the human systemic arterial system

    NASA Astrophysics Data System (ADS)

    Majka, Marcin; Gadda, Giacomo; Taibi, Angelo; Gałązka, Mirosław; Zieliński, Piotr

    2017-03-01

    We have developed a numerical simulation method for predicting the time dependence (wave form) of pressure at any location in the systemic arterial system in humans. The method uses the matlab-Simulink environment. The input data include explicitly the geometry of the arterial tree, treated up to an arbitrary bifurcation level, and the elastic properties of arteries as well as rheological parameters of blood. Thus, the impact of anatomic details of an individual subject can be studied. The method is applied here to reveal the earliest stages of mechanical reaction of the pressure profiles to sudden local blockages (thromboses or embolisms) of selected arteries. The results obtained with a purely passive model provide reference data indispensable for studies of longer-term effects due to neural and humoral mechanisms. The reliability of the results has been checked by comparison of two available sets of anatomic, elastic, and rheological data involving (i) 55 and (ii) 138 arterial segments. The remaining arteries have been replaced with the appropriate resistive elements. Both models are efficient in predicting an overall shift of pressure, whereas the accuracy of the 55-segment model in reproducing the detailed wave forms and stabilization times turns out dependent on the location of the blockage and the observation point.

  19. Identification of the earliest collagen- and plant-based coatings from Neolithic artefacts (Nahal Hemar cave, Israel).

    PubMed

    Solazzo, Caroline; Courel, Blandine; Connan, Jacques; van Dongen, Bart E; Barden, Holly; Penkman, Kirsty; Taylor, Sheila; Demarchi, Beatrice; Adam, Pierre; Schaeffer, Philippe; Nissenbaum, Arie; Bar-Yosef, Ofer; Buckley, Michael

    2016-08-09

    Mortuary practices in human evolution record cognitive, social changes and technological innovations. The Neolithic Revolution in the Levant was a watershed in this domain that has long fascinated the archaeological community. Plaster modelled skulls are well known at Jericho and several other Neolithic sites, and in Nahal Hemar cave (Israel, ca. 8200 -7300 cal. BC) excavations yielded six unique human skulls covered with a black organic coating applied in a net pattern evoking a headdress. This small cave was used as storage for paraphernalia in the semi-arid area of the Judean desert and the dry conditions preserved other artefacts such as baskets coated with a similar dark substance. While previous analysis had revealed the presence of amino acids consistent with a collagen signature, in the present report, specific biomarkers were characterised using combined proteomic and lipid approaches. Basket samples yielded collagen and blood proteins of bovine origin (Bos genus) and a large sequence coverage of a plant protein charybdin (Charybdis genus). The skull residue samples were dominated by benzoate and cinnamate derivatives and triterpenes consistent with a styrax-type resin (Styrax officinalis), thus providing the earliest known evidence of an odoriferous plant resin used in combination with an animal product.

  20. Changing the picture of Earth's earliest fossils (3.5-1.9 Ga) with new approaches and new discoveries.

    PubMed

    Brasier, Martin D; Antcliffe, Jonathan; Saunders, Martin; Wacey, David

    2015-04-21

    New analytical approaches and discoveries are demanding fresh thinking about the early fossil record. The 1.88-Ga Gunflint chert provides an important benchmark for the analysis of early fossil preservation. High-resolution analysis of Gunflintia shows that microtaphonomy can help to resolve long-standing paleobiological questions. Novel 3D nanoscale reconstructions of the most ancient complex fossil Eosphaera reveal features hitherto unmatched in any crown-group microbe. While Eosphaera may preserve a symbiotic consortium, a stronger conclusion is that multicellular morphospace was differently occupied in the Paleoproterozoic. The 3.46-Ga Apex chert provides a test bed for claims of biogenicity of cell-like structures. Mapping plus focused ion beam milling combined with transmission electron microscopy data demonstrate that microfossil-like taxa, including species of Archaeoscillatoriopsis and Primaevifilum, are pseudofossils formed from vermiform phyllosilicate grains during hydrothermal alteration events. The 3.43-Ga Strelley Pool Formation shows that plausible early fossil candidates are turning up in unexpected environmental settings. Our data reveal how cellular clusters of unexpectedly large coccoids and tubular sheath-like envelopes were trapped between sand grains and entombed within coatings of dripstone beach-rock silica cement. These fossils come from Earth's earliest known intertidal to supratidal shoreline deposit, accumulated under aerated but oxygen poor conditions.

  1. New dinosaur (Theropoda, stem-Averostra) from the earliest Jurassic of the La Quinta formation, Venezuelan Andes

    PubMed Central

    Langer, Max C.; Rincón, Ascanio D.; Ramezani, Jahandar; Solórzano, Andrés; Rauhut, Oliver W. M.

    2014-01-01

    Dinosaur skeletal remains are almost unknown from northern South America. One of the few exceptions comes from a small outcrop in the northernmost extension of the Andes, along the western border of Venezuela, where strata of the La Quinta Formation have yielded the ornithischian Laquintasaura venezuelae and other dinosaur remains. Here, we report isolated bones (ischium and tibia) of a small new theropod, Tachiraptor admirabilis gen. et sp. nov., which differs from all previously known members of the group by an unique suite of features of its tibial articulations. Comparative/phylogenetic studies place the new form as the sister taxon to Averostra, a theropod group that is known primarily from the Middle Jurassic onwards. A new U–Pb zircon date (isotope dilution thermal-ionization mass spectrometry; ID-TIMS method) from the bone bed matrix suggests an earliest Jurassic maximum age for the La Quinta Formation. A dispersal–vicariance analysis suggests that such a stratigraphic gap is more likely to be filled by new records from north and central Pangaea than from southern areas. Indeed, our data show that the sampled summer-wet equatorial belt, which yielded the new taxon, played a pivotal role in theropod evolution across the Triassic–Jurassic boundary. PMID:26064540

  2. Microscopic endometrial perivascular epithelioid cell nodules: a case report with the earliest presentation of a uterine perivascular epithelioid cell tumor.

    PubMed

    Fang, Chia-Lang; Lin, Yun-Ho; Chen, Wei-Yu

    2012-09-03

    Perivascular epithelioid cell (PEC) tumors (PEComas) are a family of related mesenchymal tumors composed of PECs which co-express melanocytic and smooth muscle markers. Although their distinctive histologic, immunohistochemical, ultrastructural, and genetic features have been clearly demonstrated, their histogenesis and normal counterpart remain largely unknown. Precursor lesions of PEComas have rarely been reported. We herein describe a tuberous sclerosis patient with microscopic PEC nodules in the endometrium of adenomyosis, pelvic endometriosis, an ovarian endometriotic cyst, and the endometrium of the uterine cavity. The nodules showed a mixture of spindle-shaped and epithelioid cells concentrically arranged around small arteries. The cells exhibited uniform nuclei, light eosinophilic cytoplasm, and immunoreactivity with HMB-45 and CD10. Some nodules revealed continuity with a PEComa in the myometrium. These findings support microscopic endometrial PEC nodules possibly being precursor lesions of uterine PEComas. The wide distribution of the nodules in the pelvis may be related to the multicentricity of PEComas in tuberous sclerosis patients. Owing to the immunoreactivity with CD10, microscopic endometrial PEC nodules may be misinterpreted as endothelial stromal cells unless melanocytic markers are stained. To the best of our knowledge, this is a case with the earliest manifestation of PEC lesions occurring in the endometrium. Virtual slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9658280017862643.

  3. The early Middle Pleistocene archeopaleontological site of Wadi Sarrat (Tunisia) and the earliest record of Bos primigenius

    NASA Astrophysics Data System (ADS)

    Martínez-Navarro, Bienvenido; Karoui-Yaakoub, Narjess; Oms, Oriol; Amri, Lamjed; López-García, Juan Manuel; Zerai, Kamel; Blain, Hugues-Alexandre; Mtimet, Moncef-Saïd; Espigares, María-Patrocinio; Ben Haj Ali, Nebiha; Ros-Montoya, Sergio; Boughdiri, Mabrouk; Agustí, Jordi; Khayati-Ammar, Hayet; Maalaoui, Kamel; El Khir, Maahmoudi Om; Sala, Robert; Othmani, Abdelhak; Hawas, Ramla; Gómez-Merino, Gala; Solè, Àlex; Carbonell, Eudald; Palmqvist, Paul

    2014-04-01

    Here we describe the new, rich lacustrine paleontological and archeological site of Wadi Sarrat (Le Kef, northeastern Tunisia), dated to the beginning of the Middle Pleistocene, ˜0.7 Ma, by a combination of paleomagnetism and biochronology. This locality preserves the earliest record of auroch, Bos primigenius, the ancestor of the worldwide extant domestic cattle species Bos taurus, which is represented by a nearly complete, giant-sized cranium (specimen OS1). Both the cranial anatomy and the size of this specimen reflect the phylogenetic legacy inherited from its ancestor, the late Early Pleistocene African Bos buiaensis, recorded in the eastern African paleoanthropological site of Buia, Eritrea (1.0 Ma). Given that the latter species is an evolved form of the classical Early Pleistocene African buffalo Pelorovis oldowayensis, the finding of B. primigenius at Wadi Sarrat shows that the genus Bos evolved in Africa and dispersed into Eurasia at the beginning of the Middle Pleistocene, which coincides with the spread of the Acheulian technocomplex in northern Africa and Europe. Therefore, the lineage of Pelorovis-Bos has been part of the human ecological landscape since the appearance of the genus Homo in the African Early Pleistocene.

  4. Changing the picture of Earth's earliest fossils (3.5-1.9 Ga) with new approaches and new discoveries

    NASA Astrophysics Data System (ADS)

    Brasier, Martin D.; Antcliffe, Jonathan; Saunders, Martin; Wacey, David

    2015-04-01

    New analytical approaches and discoveries are demanding fresh thinking about the early fossil record. The 1.88-Ga Gunflint chert provides an important benchmark for the analysis of early fossil preservation. High-resolution analysis of Gunflintia shows that microtaphonomy can help to resolve long-standing paleobiological questions. Novel 3D nanoscale reconstructions of the most ancient complex fossil Eosphaera reveal features hitherto unmatched in any crown-group microbe. While Eosphaera may preserve a symbiotic consortium, a stronger conclusion is that multicellular morphospace was differently occupied in the Paleoproterozoic. The 3.46-Ga Apex chert provides a test bed for claims of biogenicity of cell-like structures. Mapping plus focused ion beam milling combined with transmission electron microscopy data demonstrate that microfossil-like taxa, including species of Archaeoscillatoriopsis and Primaevifilum, are pseudofossils formed from vermiform phyllosilicate grains during hydrothermal alteration events. The 3.43-Ga Strelley Pool Formation shows that plausible early fossil candidates are turning up in unexpected environmental settings. Our data reveal how cellular clusters of unexpectedly large coccoids and tubular sheath-like envelopes were trapped between sand grains and entombed within coatings of dripstone beach-rock silica cement. These fossils come from Earth's earliest known intertidal to supratidal shoreline deposit, accumulated under aerated but oxygen poor conditions.

  5. The earliest molecular response to stretch of insect flight muscle as revealed by fast X-ray diffraction recording

    PubMed Central

    Iwamoto, Hiroyuki

    2017-01-01

    Small insects drive their flight muscle at frequencies up to 1,000 Hz. This remarkable ability owes to the mechanism of stretch activation. However, it remains unknown as to what sarcomeric component senses the stretch and triggers the following force generation. Here we show that the earliest structural change after a step stretch is reflected in the blinking of the 111 and 201 reflections, as observed in the fast X-ray diffraction recording from isolated bumblebee flight muscle fibers. The same signal has also been observed in live bumblebee. We demonstrate that (1) the signal responds almost concomitantly to a quick step stretch, (2) the signal grows with increasing calcium levels as the stretch-activated force does, and (3) a full 3-dimensional model demonstrates that the signal is maximized when objects having a 38.7-nm actin periodicity travel by ~20 nm along the filament axis. This is the expected displacement if myosin heads are loosely associated with actin target zones (where actin monomers are favorably oriented), and are dragged by a 1.3% stretch, which effectively causes stretch-induced activation. These results support and strengthen our proposal that the myosin head itself acts as the stretch sensor, after calcium-induced association with actin in a low-force form. PMID:28176871

  6. The earliest occurrence of the steppe pika (Ochotona pusilla) in Europe near the Pliocene/Pleistocene boundary.

    PubMed

    Fostowicz-Frelik, Lucja; Frelik, Grzegorz J

    2010-03-01

    The steppe pika (Ochotona pusilla), a representative of the lagomorph family Ochotonidae, is restricted today to Kazakhstan and Russia. This subspecies-rich form belongs to a morphologically distinct, monospecific group of relatively small pikas, inhabiting steppe-like habitat. In the fossil record, it serves as a bioindicator of dry, grassland environment. The steppe pika was abundant and widespread in Europe during the Last Glaciation, and its unquestionable presence has been reported there since the middle Pleistocene. A new discovery of O. pusilla, from the Kielniki 3B locality (Poland), dated to the latest Pliocene, moves back the species appearance in Europe about one million years, almost coeval with its first record from the late Pliocene of Kazakhstan. Presence of such a typical steppe inhabitant as O. pusilla indicates significant climate change towards more arid, continental conditions, which started influencing Europe at 2.6 Ma. We present the first reliable record of the earliest O. pusilla entry deep into Europe in the latest Pliocene.

  7. Onwards and upwards in the Caucasus - A multidisciplinary approach to understanding the lifeways of the earliest modern humans in Armenia

    NASA Astrophysics Data System (ADS)

    Kandel, Andrew; Gasparyan, Boris; Bruch, Angela; Deckers, Katleen; Nahapetyan, Samvel; Weissbrod, Lior

    2013-04-01

    The Armenian Highlands have functioned as a gateway with regards to the peopling of the Southern Caucasus. Most importantly, changes in climate have long controlled access to this remote and often inhospitable mountainous region. Here we present the results of the multidisciplinary study of Aghitu-3 Cave which brings together researchers from the fields of archaeology, geology and geomorphology, zooarchaeology, paleobotany and paleoclimate. By integrating these areas of study, we have reconstructed the lifeways of the earliest behaviorally (and presumably anatomically) modern humans who settled Southern Armenia about 35,000 (cal BP) years ago and placed this occupational sequence within a framework of environmental change. These first Upper Paleolithic inhabitants of Armenia made temporary use of this basalt cave located along the Vorotan River corridor at an altitude of 1601 m during seasonal forays into the highlands. The infrequent use of this site as a hunting camp comes to an end at about 31,000 cal BP. The next package of sediment shows little evidence of human occupation, although fauna seem to flourish during the time between 31-29,000 cal BP. Following this phase of depopulation, the intensity of occupation increases substantially after 29,000 cal BP. Human presence is amply documented in the numerous stone artifacts, faunal remains and fireplaces that cover the site. These changes in population movement are echoed in the sequence of sediments preserved in the cave and can be correlated with the fluctuating climatic conditions associated with the late Pleistocene.

  8. The Earliest Known Americans

    ERIC Educational Resources Information Center

    MOSAIC, 1977

    1977-01-01

    Describes archaeological research in the United States. Reconstructs history of Paleo-Indian migrations, discussing archaeological evidence and opposing views regarding specific dates. Reveals cultural details gathered from specific studies at Meadowcroft (Pennsylvania) and Thunderbird (Virginia). (CS)

  9. The earliest medical texts.

    PubMed

    Frey, E F

    The first civilization known to have had an extensive study of medicine and to leave written records of its practices and procedures was that of ancient Egypt. The oldest extant Egyptian medical texts are six papyri from the period between 2000 B.C. and 1500 B.C.: the Kahun Medical Papyrus, the Ramesseum IV and Ramesseum V Papyri, the Edwin Smith Surgical Papyrus, The Ebers Medical Papyrus and the Hearst Medical Papyrus. These texts, most of them based on older texts dating possibly from 3000 B.C., are comparatively free of the magician's approach to treating illness. Egyptian medicine influenced the medicine of neighboring cultures, including the culture of ancient Greece. From Greece, its influence spread onward, thereby affecting Western civilization significantly.

  10. Family Life

    MedlinePlus

    ... With Family and Friends > Family Life Request Permissions Family Life Approved by the Cancer.Net Editorial Board , ... your outlook on the future. Friends and adult family members The effects of cancer on your relationships ...

  11. Earliest Silicic Volcanism Associated with Mid-Miocene Flood Basalts: Tuffs Interbedded with Steens Basalt, Nevada and Oregon

    NASA Astrophysics Data System (ADS)

    Luckett, M.; Mahood, G. A.; Benson, T. R.

    2013-12-01

    have analyzed the vitrophyres of these four tuffs and, accounting for possible crystal enrichment/depletion in fall deposits and the observed mineralogy, we believe they represent eruption of an alkali rhyolite, two trachydacites and one trachyte. In their weakly alkalic composition they are most similar to the more alkalic lavas from the Hawks Valley/Lone Mountain center or the oldest ignimbrite from High Rock Caldera Complex, the Idaho Canyon Tuff. They appear to be insufficiently allkalic to come from McDermitt Caldera Field. Jarboe et al. (2010) report a reverse paleomagnetic polarity for a sample of Steens Basalt within the section in the southern Pueblo Mountains, making it equivalent to lower Steens Basalt at the type section at Steens Mountain. This suggests that at least minor silicic volcanism accompanied the earliest stages of flood basalt magmatism. We have irradiated alkali feldspar from the fused tuffs for 40Ar/39Ar analysis, and will present this data as a way to determine the timing of these earliest silicic eruptions, and to provide ages for Steens basalt lavas more precise than can be obtained on the low-K basalts themselves.

  12. The ear region of earliest known elephant relatives: new light on the ancestral morphotype of proboscideans and afrotherians.

    PubMed

    Schmitt, Arnaud; Gheerbrant, Emmanuel

    2016-01-01

    One of the last major clades of placental mammals recognized was the Afrotheria, which comprises all main endemic African mammals. This group includes the ungulate-like paenungulates, and among them the elephant order Proboscidea. Among afrotherians, the petrosal anatomy remains especially poorly known in Proboscidea. We provide here the first comparative CT scan study of the ear region of the two earliest known proboscideans (and paenungulates), Eritherium and Phosphatherium, from the mid Palaeocene and early Eocene of Morocco. It is helpful to characterize the ancestral morphotype of Proboscidea to understand petrosal evolution within proboscideans and afrotherians. The petrosal structure of these two taxa shows several differences. Eritherium is more primitive than Phosphatherium and closer to the basal paenungulate Ocepeia in several traits (inflated tegmen tympani, very deep fossa subarcuata and ossified canal for ramus superior of stapedial artery). Phosphatherium, however, retains plesiomorphies such as a true crus commune secundaria. A cladistic analysis of petrosal traits of Eritherium and Phosphatherium among Proboscidea results in a single tree with a low level of homoplasy in which Eritherium, Phosphatherium and Numidotherium are basal. This contrasts with previous phylogenetic studies showing homoplasy in petrosal evolution among Tethytheria. It suggests that evolutionary modalities of petrosal characters differ with the taxonomic level among Afrotheria: noticeable convergences occurred among the paenungulate orders, whereas little homoplasy seems to have occurred at intra-ordinal level in orders such as Proboscidea. Most petrosal features of both Eritherium and Phosphatherium are primitive. The ancestral petrosal morphotype of Proboscidea was not specialized but was close to the generalized condition of paenungulates, afrotherians, and even eutherians. This is consistent with cranial and dental characters of Eritherium, suggesting that the ancestral

  13. Gene Expression in Wilms’ Tumor Mimics the Earliest Committed Stage in the Metanephric Mesenchymal-Epithelial Transition

    PubMed Central

    Li, Chi-Ming; Guo, Meirong; Borczuk, Alain; Powell, Charles A.; Wei, Michelle; Thaker, Harshwardhan M.; Friedman, Richard; Klein, Ulf; Tycko, Benjamin

    2002-01-01

    Wilms’ tumor (WT) has been considered a prototype for arrested cellular differentiation in cancer, but previous studies have relied on selected markers. We have now performed an unbiased survey of gene expression in WTs using oligonucleotide microarrays. Statistical criteria identified 357 genes as differentially expressed between WTs and fetal kidneys. This set contained 124 matches to genes on a microarray used by Stuart and colleagues (Stuart RO, Bush KT, Nigam SK: Changes in global gene expression patterns during development and maturation of the rat kidney. Proc Natl Acad Sci USA 2001, 98:5649–5654) to establish genes with stage-specific expression in the developing rat kidney. Mapping between the two data sets showed that WTs systematically overexpressed genes corresponding to the earliest stage of metanephric development, and underexpressed genes corresponding to later stages. Automated clustering identified a smaller group of 27 genes that were highly expressed in WTs compared to fetal kidney and heterologous tumor and normal tissues. This signature set was enriched in genes encoding transcription factors. Four of these, PAX2, EYA1, HBF2, and HOXA11, are essential for cell survival and proliferation in early metanephric development, whereas others, including SIX1, MOX1, and SALL2, are predicted to act at this stage. SIX1 and SALL2 proteins were expressed in the condensing mesenchyme in normal human fetal kidneys, but were absent (SIX1) or reduced (SALL2) in cells at other developmental stages. These data imply that the blastema in WTs has progressed to the committed stage in the mesenchymal-epithelial transition, where it is partially arrested in differentiation. The WT-signature set also contained the Wnt receptor FZD7, the tumor antigen PRAME, the imprinted gene NNAT and the metastasis-associated transcription factor E1AF. PMID:12057921

  14. Geometric Corroboration of the Earliest Lensed Galaxy at z ≃ 10.8 from Robust Free-form Modelling

    NASA Astrophysics Data System (ADS)

    Chan, Brian M. Y.; Broadhurst, Tom; Lim, Jeremy; Diego, Jose M.; Zitrin, Adi; Coe, Dan; Ford, Holland C.

    2017-01-01

    A multiply lensed galaxy, MACS0647-JD, with a probable photometric redshift of z≃ {10.7}-0.4+0.6 is claimed to constitute one of the very earliest known galaxies, formed well before reionization was completed. However, spectral evidence that MACS0647-JD lies at high redshift has proven infeasible and so here we seek an independent-lensing-based “geometric redshift” derived from the angles between the three lensed images of MACS0647-JD, using our free-form mass model (WSLAP+) for the lensing cluster MACSJ0647.7+7015 (at z = 0.591). Our lens model uses the nine sets of multiple images, including those of MACS0647-JD, identified by the CLASH survey toward this cluster. We convincingly exclude the low-redshift regime of z < 3, for which convoluted critical curves are generated by our method, as the solution bends to accommodate the wide angles of MACS0647-JD for this low redshift. Instead, a best fit to all sets of lensed galaxy positions and redshifts provides a geometric redshift of z≃ {10.8}-0.4+0.3 for MACS0647-JD, strongly supporting the higher photometric redshift solution. Importantly, we find a tight linear relation between the relative brightnesses of all nine sets of multiply lensed images and their relative magnifications as predicted by our model. This agreement provides a benchmark for the quality of the lens model, and establishes the robustness of our free-form lensing method for measuring model-independent geometric source distances and for deriving objective central cluster mass distributions. After correcting for its magnification the luminosity of MACS0647-JD remains relatively high at MUV = ‑19.4, which is within a factor of a few in flux of some surprisingly luminous z ≃ 10–11 candidates discovered recently in Hubble blank field surveys.

  15. Late Paleocene fossils from the Cerrejón Formation, Colombia, are the earliest record of Neotropical rainforest

    PubMed Central

    Wing, Scott L.; Herrera, Fabiany; Jaramillo, Carlos A.; Gómez-Navarro, Carolina; Wilf, Peter; Labandeira, Conrad C.

    2009-01-01

    Neotropical rainforests have a very poor fossil record, making hypotheses concerning their origins difficult to evaluate. Nevertheless, some of their most important characteristics can be preserved in the fossil record: high plant diversity, dominance by a distinctive combination of angiosperm families, a preponderance of plant species with large, smooth-margined leaves, and evidence for a high diversity of herbivorous insects. Here, we report on an ≈58-my-old flora from the Cerrejón Formation of Colombia (paleolatitude ≈5 °N) that is the earliest megafossil record of Neotropical rainforest. The flora has abundant, diverse palms and legumes and similar family composition to extant Neotropical rainforest. Three-quarters of the leaf types are large and entire-margined, indicating rainfall >2,500 mm/year and mean annual temperature >25 °C. Despite modern family composition and tropical paleoclimate, the diversity of fossil pollen and leaf samples is 60–80% that of comparable samples from extant and Quaternary Neotropical rainforest from similar climates. Insect feeding damage on Cerrejón fossil leaves, representing primary consumers, is abundant, but also of low diversity, and overwhelmingly made by generalist feeders rather than specialized herbivores. Cerrejón megafossils provide strong evidence that the same Neotropical rainforest families have characterized the biome since the Paleocene, maintaining their importance through climatic phases warmer and cooler than present. The low diversity of both plants and herbivorous insects in this Paleocene Neotropical rainforest may reflect an early stage in the diversification of the lineages that inhabit this biome, and/or a long recovery period from the terminal Cretaceous extinction. PMID:19833876

  16. Toros-Menalla (Chad, 7 Ma), the earliest hominin-bearing area: How many mammal paleocommunities?

    PubMed

    Le Fur, Soizic; Fara, Emmanuel; Mackaye, Hassane Taïsso; Vignaud, Patrick; Brunet, Michel

    2014-04-01

    The fossiliferous area of Toros-Menalla (TM) (Djurab Desert, northern Chad) has yielded one of the richest African mammal faunas of the late Miocene. It is also the place where the earliest known hominin, Sahelanthropus tchadensis, was found. Although more than 300 localities are recorded in that area, previous paleoecological studies focused only on the largest and richest one. The integration of the material from other TM localities, and thus of a significant number of mammal taxa, is crucial to improve the corresponding paleoenvironmental reconstructions. Before such inferences can be drawn, it is necessary to test for the ecological integrity of these mammal assemblages: how many paleocommunities do they represent? The faunal structures of several assemblages selected for their apparent resilience to sampling biases are compared here. The criteria used in the inter-assemblage comparison are ecological diversity, taxonomic structure (taxonomic rank of abundance) and taxonomic composition. Based on multivariate analyses, two groups of TM assemblages can be distinguished. One of them contains the hominin-bearing assemblages. It is taxonomically richer and shows a wider ecological spectrum than its counterpart. The degree of taphonomic alteration undergone by the TM assemblages, as well as the distribution of amphibious mammals among them, suggest different depositional settings for these two groups of assemblages, the richest of which was probably associated with lower hydraulic energy. Overall, it seems that the TM assemblages recorded the same mammal paleocommunity preserved in two contrasted depositional settings. Moreover, the spatial overlap of these assemblages provides further evidence for the mosaic character of the landscape associated with S. tchadensis.

  17. Earliest evidence for caries and exploitation of starchy plant foods in Pleistocene hunter-gatherers from Morocco

    PubMed Central

    Humphrey, Louise T.; De Groote, Isabelle; Morales, Jacob; Barton, Nick; Collcutt, Simon; Bronk Ramsey, Christopher; Bouzouggar, Abdeljalil

    2014-01-01

    Dental caries is an infectious disease that causes tooth decay. The high prevalence of dental caries in recent humans is attributed to more frequent consumption of plant foods rich in fermentable carbohydrates in food-producing societies. The transition from hunting and gathering to food production is associated with a change in the composition of the oral microbiota and broadly coincides with the estimated timing of a demographic expansion in Streptococcus mutans, a causative agent of human dental caries. Here we present evidence linking a high prevalence of caries to reliance on highly cariogenic wild plant foods in Pleistocene hunter-gatherers from North Africa, predating other high caries populations and the first signs of food production by several thousand years. Archaeological deposits at Grotte des Pigeons in Morocco document extensive evidence for human occupation during the Middle Stone Age and Later Stone Age (Iberomaurusian), and incorporate numerous human burials representing the earliest known cemetery in the Maghreb. Macrobotanical remains from occupational deposits dated between 15,000 and 13,700 cal B.P. provide evidence for systematic harvesting and processing of edible wild plants, including acorns and pine nuts. Analysis of oral pathology reveals an exceptionally high prevalence of caries (51.2% of teeth in adult dentitions), comparable to modern industrialized populations with a diet high in refined sugars and processed cereals. We infer that increased reliance on wild plants rich in fermentable carbohydrates and changes in food processing caused an early shift toward a disease-associated oral microbiota in this population. PMID:24395774

  18. RAPTOR: Closed-Loop monitoring of the night sky and the earliest optical detection of GRB 021211

    NASA Astrophysics Data System (ADS)

    Vestrand, W. T.; Borozdin, K.; Casperson, D. J.; Fenimore, E.; Galassi, M.; McGowan, K.; Starr, D.; White, R. R.; Wozniak, P.; Wren, J.

    2004-10-01

    We discuss the RAPTOR (Rapid Telescopes for Optical Response) sky monitoring system at Los Alamos National Laboratory. RAPTOR is a fully autonomous robotic system that is designed to identify and make follow-up observations of optical transients with durations as short as one minute. The RAPTOR design is based on Biomimicry of Human Vision. The sky monitor is composed of two identical arrays of telescopes, separated by 38 kilometers, which stereoscopically monitor a field of about 1300 square-degrees for transients. Both monitoring arrays are carried on rapidly slewing mounts and are composed of an ensemble of wide-field telescopes clustered around a more powerful narrow-field telescope called the ``fovea'' telescope. All telescopes are coupled to real-time analysis pipelines that identify candidate transients and relay the information to a central decision unit that filters the candidates to find real celestial transients and command a response. When a celestial transient is found, the system can point the fovea telescopes to any position on the sky within five seconds and begin follow-up observations. RAPTOR also responds to Gamma Ray Burst (GRB) alerts generated by GRB monitoring spacecraft. Here we present RAPTOR observations of GRB 021211 that constitute the earliest detection of optical emission from that event and are the second fastest achieved for any GRB. The detection of bright optical emission from GRB021211, a burst with modest gamma-ray fluence, indicates that prompt optical emission, detectable with small robotic telescopes, is more common than previously thought. Further, the very fast decline of the optical afterglow from GRB 021211 suggests that some so-called ``optically dark'' GRBs were not detected only because of the slow response of the follow-up telescopes.

  19. Searching for Life on Early Mars: Lessons from the Pilbara

    NASA Technical Reports Server (NTRS)

    Clarke, J. D. A.; Stoker, C. R.

    2016-01-01

    Stromatolites in the Pilbara region of Western Australia constitute the earliest outcrop-scale evidence of life on Earth (Figure 1). The stromatolites in the 3.4 Ga Strelley Pool Formation (SPF) provide an important analog for searching for fossil evidence of early life on Mars, as Noachian aged sediments on Mars were formed under similar environmental conditions. Stromatolites represent possibly the best evidence that could be collected by a rover because they form recognizable macroscopic structures and are often associated with chemical and microscopic evidence.

  20. The secret of life

    NASA Astrophysics Data System (ADS)

    Jenkins, David; Kirsebom, Oliver

    2013-02-01

    Life as we know it would not be possible were it not for a particular nuclear energy level of carbon-12 predicted 60 years ago by Fred Hoyle. But the true nature of this energy level remains one of the biggest unsolved questions in nuclear physics, say David Jenkins and Oliver Kirsebom.

  1. Chemicals in Everyday Life.

    ERIC Educational Resources Information Center

    Seymour, Raymond B.

    1987-01-01

    Discusses the dependencies of people on chemicals in various aspects of life. Describes some of the natural and synthetic chemicals currently used in food production, clothing, shelter, travel and exploration, sports and recreation, ventilation, heating and cooling, communications, decoration, sanitation, and education. (TW)

  2. Life! Through Play.

    ERIC Educational Resources Information Center

    Van Anne, Nancy

    This speech presents a review of research concerning the nature of play. Some of the formal characteristics of play are: (a) it is distinct from ordinary life in its "temporariness" and its limitless location; (b) there is an element of tension in play that leads to uncertainty concerning the outcome but at the same time provides the opportunity…

  3. Roots: The Life Space Pioneers

    ERIC Educational Resources Information Center

    James, Adrienne Brant

    2008-01-01

    Traditional approaches to education and youth work were transformed by two psychologists who came to the United States as Hitler rose to power. Practical theorist Kurt Lewin challenged mechanistic ideas of behavior by studying children in their natural "life space." Theory practitioner Fritz Redl applied life space concepts to work with…

  4. Stable isotope paleoclimatology of the earliest Eocene using kimberlite-hosted mummified wood from the Canadian Subarctic

    NASA Astrophysics Data System (ADS)

    Hook, B. A.; Halfar, J.; Gedalof, Z.; Bollmann, J.; Schulze, D. J.

    2015-10-01

    The recent discovery of well-preserved mummified wood buried within a subarctic kimberlite diamond mine prompted a paleoclimatic study of the early Eocene "hothouse" (ca. 53.3 Ma). At the time of kimberlite eruption, the Subarctic was warm and humid producing a temperate rainforest biome well north of the Arctic Circle. Previous studies have estimated that mean annual temperatures in this region were 4-20 °C in the early Eocene, using a variety of proxies including leaf margin analysis and stable isotopes (δ13C and δ18O) of fossil cellulose. Here, we examine stable isotopes of tree-ring cellulose at subannual- to annual-scale resolution, using the oldest viable cellulose found to date. We use mechanistic models and transfer functions to estimate earliest Eocene temperatures using mummified cellulose, which was well preserved in the kimberlite. Multiple samples of Piceoxylon wood within the kimberlite were crossdated by tree-ring width. Multiple proxies are used in combination to tease apart likely environmental factors influencing the tree physiology and growth in the unique extinct ecosystem of the Polar rainforest. Calculations of interannual variation in temperature over a multidecadal time-slice in the early Eocene are presented, with a mean annual temperature (MAT) estimate of 11.4 °C (1 σ = 1.8 °C) based on δ18O, which is 16 °C warmer than the current MAT of the area (-4.6 °C). Early Eocene atmospheric δ13C (δ13Catm) estimates were -5.5 (±0.7) ‰. Isotopic discrimination (Δ) and leaf intercellular pCO2 ratio (ci/ca) were similar to modern values (Δ = 18.7 ± 0.8 ‰; ci/ca = 0.63 ± 0.03 %), but intrinsic water use efficiency (Early Eocene iWUE = 211 ± 20 μmol mol-1) was over twice the level found in modern high-latitude trees. Dual-isotope spectral analysis suggests that multidecadal climate cycles somewhat similar to the modern Pacific Decadal Oscillation likely drove temperature and cloudiness trends on 20-30-year timescales, influencing

  5. The He isotope composition of the earliest picrites erupted by the Ethiopia plume, implications for mantle plume source

    NASA Astrophysics Data System (ADS)

    Stuart, Finlay; Rogers, Nick; Davies, Marc

    2016-04-01

    The earliest basalts erupted by mantle plumes are Mg-rich, and typically derived from mantle with higher potential temperature than those derived from the convecting upper mantle at mid-ocean ridges and ocean islands. The chemistry and isotopic composition of picrites from CFB provide constraints on the composition of deep Earth and thus the origin and differentiation history. We report new He-Sr-Nd-Pb isotopic composition of the picrites from the Ethiopian flood basalt province from the Dilb (Chinese Road) section. They are characterized by high Fe and Ti contents for MgO = 10-22 wt. % implying that the parent magma was derived from a high temperature low melt fraction, most probably from the Afar plume head. The picrite 3He/4He does not exceed 21 Ra, and there is a negative correlation with MgO, the highest 3He/4He corresponding to MgO = 15.4 wt. %. Age-corrected 87Sr/86Sr (0.70392-0.70408) and 143Nd/144Nd (0.512912-0.512987) display little variation and are distinct from MORB and OIB. Age-corrected Pb isotopes display a significant range (e.g. 206Pb/204Pb = 18.70-19.04) and plot above the NHRL. These values contrast with estimates of the modern Afar mantle plume which has lower 3He/4He and Sr, Nd and Pb isotope ratios that are more comparable with typical OIB. These results imply either interaction between melts derived from the Afar mantle plume and a lithospheric component, or that the original Afar mantle plume had a rather unique radiogenic isotope composition. Regardless of the details of the origins of this unusual signal, our observations place a minimum 3He/4He value of 21 Ra for the Afar mantle plume, significantly greater than the present day value of 16 Ra, implying a significant reduction over 30 Myr. In addition the Afar source was less degassed than convecting mantle but more degassed than mantle sampled by the proto-Iceland plume (3He/4He ~50 Ra). This suggests that the largest mantle plumes are not sourced in a single deep mantle domain with a

  6. Interbasinal correlation between Jameson Land and Hold-with-Hope (Northeast Greenland) organic carbon isotope records during the latest Permian-earliest Triassic

    NASA Astrophysics Data System (ADS)

    Sanson Barrera, Anna; Meier, Maximiliano; Hochuli, Peter A.; Bucher, Hugo; Weissert, Helmut; Bernasconi, Stefano M.

    2015-04-01

    Latest Permian-earliest Triassic sequences in Northeast Greenland were deposited during the main rift phase between the two margins of the Greenland-Norway Basin, and were influenced by several relative sea-level fluctuations. The associated crustal extension created several sub-basins that led to marked lateral thicknesses between the latest Permian and earliest Triassic formations. These formations outcrop along the Northeast Greenland coast and can be followed from Jameson Land around 71°N up to Wollaston Forland around 74.5°N. Due to a latest Permian relative sea-level fall, northern sub-basins show a sedimentary gap close to the Permian-Triassic boundary, while southern sub-basins show continuous sedimentation across the Permian-Triassic transition. Earlier studies focused just on the Permian-Triassic boundary from continuous sections from Jameson Land. This study presents the correlation between two new sections from Jameson Land, and one section of a northern sub-basin (Hold-with-Hope) merging terrestrial and marine geochemical and paleontological data. The combination of organic carbon isotopes, palynofacies and palynology analyses, few ammonoids belonging to the Ophiceratidae family found in the sections, and sedimentological observations provides a robust correlation between both sub-basins, and the first interbasinal organic carbon isotope correlation for Northeast Greenland during the latest Permian-earliest Triassic.

  7. Gaia and natural selection

    NASA Astrophysics Data System (ADS)

    Lenton, Timothy M.

    1998-07-01

    Evidence indicates that the Earth self-regulates at a state that is tolerated by life, but why should the organisms that leave the most descendants be the ones that contribute to regulating their planetary environment? The evolving Gaia theory focuses on the feedback mechanisms, stemming from naturally selected traits of organisms, that could generate such self-regulation.

  8. Family Life.

    ERIC Educational Resources Information Center

    Naturescope, 1986

    1986-01-01

    Focuses on various aspects of mammal family life ranging from ways different species are born to how different mammals are raised. Learning activities include making butter from cream, creating birth announcements for mammals, and playing a password game on family life. (ML)

  9. Life sciences

    SciTech Connect

    Day, L.

    1991-04-01

    This document is the 1989--1990 Annual Report for the Life Sciences Divisions of the University of California/Lawrence Berkeley Laboratory. Specific progress reports are included for the Cell and Molecular Biology Division, the Research Medicine and Radiation Biophysics Division (including the Advanced Light Source Life Sciences Center), and the Chemical Biodynamics Division. 450 refs., 46 figs. (MHB)

  10. Embryonic life and human life.

    PubMed

    Shea, M C

    1985-12-01

    A new human life comes into being not when there is mere cellular life in a human embryo, but when the newly developing body organs and systems begin to function as a whole, the author argues. This is symmetrical with the dealth of an existing human life, which occurs when its organs and systems have permanently ceased to function as a whole. Thus a new human life cannot begin until the development of a functioning brain which has begun to co-ordinate and organise the activities of the body as a whole.

  11. Living in cities, naturally.

    PubMed

    Hartig, Terry; Kahn, Peter H

    2016-05-20

    Natural features, settings, and processes in urban areas can help to reduce stress associated with urban life. In this and other ways, public health benefits from, street trees, green roofs, community gardens, parks and open spaces, and extensive connective pathways for walking and biking. Such urban design provisions can also yield ecological benefits, not only directly but also through the role they play in shaping attitudes toward the environment and environmental protection. Knowledge of the psychological benefits of nature experience supports efforts to better integrate nature into the architecture, infrastructure, and public spaces of urban areas.

  12. Defining life.

    PubMed

    Benner, Steven A

    2010-12-01

    Any definition is intricately connected to a theory that gives it meaning. Accordingly, this article discusses various definitions of life held in the astrobiology community by considering their connected "theories of life." These include certain "list" definitions and a popular definition that holds that life is a "self-sustaining chemical system capable of Darwinian evolution." We then act as "anthropologists," studying what scientists do to determine which definition-theories of life they constructively hold as they design missions to seek non-terran life. We also look at how constructive beliefs about biosignatures change as observational data accumulate. And we consider how a definition centered on Darwinian evolution might itself be forced to change as supra-Darwinian species emerge, including in our descendents, and consider the chances of our encountering supra-Darwinian species in our exploration of the Cosmos. Last, we ask what chemical structures might support Darwinian evolution universally; these structures might be universal biosignatures.

  13. Computational approaches to natural product discovery

    PubMed Central

    Medema, Marnix H.; Fischbach, Michael A.

    2016-01-01

    From the earliest Streptomyces genome sequences, the promise of natural product genome mining has been captivating: genomics and bioinformatics would transform compound discovery from an ad hoc pursuit to a high-throughput endeavor. Until recently, however, genome mining has advanced natural product discovery only modestly. Here, we argue that the development of algorithms to mine the continuously increasing amounts of (meta)genomic data will enable the promise of genome mining to be realized. We review computational strategies that have been developed to identify biosynthetic gene clusters in genome sequences and predict the chemical structures of their products. We then discuss networking strategies that can systematize large volumes of genetic and chemical data, and connect genomic information to metabolomic and phenotypic data. Finally, we provide a vision of what natural product discovery might look like in the future, specifically considering long-standing questions in microbial ecology regarding the roles of metabolites in interspecies interactions. PMID:26284671

  14. Computational approaches to natural product discovery.

    PubMed

    Medema, Marnix H; Fischbach, Michael A

    2015-09-01

    Starting with the earliest Streptomyces genome sequences, the promise of natural product genome mining has been captivating: genomics and bioinformatics would transform compound discovery from an ad hoc pursuit to a high-throughput endeavor. Until recently, however, genome mining has advanced natural product discovery only modestly. Here, we argue that the development of algorithms to mine the continuously increasing amounts of (meta)genomic data will enable the promise of genome mining to be realized. We review computational strategies that have been developed to identify biosynthetic gene clusters in genome sequences and predict the chemical structures of their products. We then discuss networking strategies that can systematize large volumes of genetic and chemical data and connect genomic information to metabolomic and phenotypic data. Finally, we provide a vision of what natural product discovery might look like in the future, specifically considering longstanding questions in microbial ecology regarding the roles of metabolites in interspecies interactions.

  15. Searching for Life: Early Earth, Mars and Beyond

    NASA Technical Reports Server (NTRS)

    DesMarais, David J.; Chang, Sherwood (Technical Monitor)

    1996-01-01

    We might be entering a golden age for exploring life throughout time and space. Rapid gene sequencing will better define our most distant ancestors. The earliest geologic evidence of life is now 3.8 billion years old. Organic matter and submicron-sized morphologies have been preserved in the martian crust for billions of years. Several new missions to Mars are planned, with a high priority on the search for life, past or present. The recent discovery of large extrasolar planets has heightened interest in spacecraft to detect small, earth-like planets. A recent workshop discussed strategies for life detection on such planets. There is much to anticipate in the near future.

  16. Defining life or bringing biology to life.

    PubMed

    Ruiz-Mirazo, Kepa; Peretó, Juli; Moreno, Alvaro

    2010-04-01

    In the present, post-genomic times, systemic or holistic approaches to living phenomena are compulsory to overcome the limits of traditional strategies, such as the methodological reductionism of molecular biology. In this paper, we propose that theoretical and philosophical efforts to define life also contribute to those integrative approaches, providing a global theoretical framework that may help to deal with or interpret the huge amount of data being collected by current high-throughput technologies, in this so-called 'omics' revolution. We claim that two fundamental notions can capture the core of the living, (basic) autonomy and open-ended evolution, and that only the complementary combination of these two theoretical constructs offers an adequate solution to the problem of defining the nature of life in specific enough-but also encompassing enough-terms. This tentative solution should also illuminate, in its most elementary version, the leading steps towards living beings on Earth.

  17. Extraterrestrial Life

    NASA Technical Reports Server (NTRS)

    Klein, M. J.

    1993-01-01

    Extraterrestrial Intelligence is intelligent life that developed somewhere other than the earth. Such life has not yet been discovered. However, scientific research, including astronomy, biology, planetary science and studies of fossils here on earth have led many scientists to conclude that such life may exist on planets orbiting at least some of the hundreds of billions of stars in our Milky Way Galaxy. Today, some researchers are trying to find evidence for extraterrestrial intelligence. This effort is often called SETI, which stands for Search for Extraterrestrial Intelligence. SETI researchers decided that looking for evidence of their technology might be the best way to discover other intelligent life in the Galaxy. They decided to use large radio telescopes to search the sky over a wide range of radio frequencies...

  18. Defining Life

    PubMed Central

    2010-01-01

    Abstract Any definition is intricately connected to a theory that gives it meaning. Accordingly, this article discusses various definitions of life held in the astrobiology community by considering their connected “theories of life.” These include certain “list” definitions and a popular definition that holds that life is a “self-sustaining chemical system capable of Darwinian evolution.” We then act as “anthropologists,” studying what scientists do to determine which definition-theories of life they constructively hold as they design missions to seek non-terran life. We also look at how constructive beliefs about biosignatures change as observational data accumulate. And we consider how a definition centered on Darwinian evolution might itself be forced to change as supra-Darwinian species emerge, including in our descendents, and consider the chances of our encountering supra-Darwinian species in our exploration of the Cosmos. Last, we ask what chemical structures might support Darwinian evolution universally; these structures might be universal biosignatures. Key Words: Evolution—Life—Life detection—Biosignatures. Astrobiology 10, 1021–1030. PMID:21162682

  19. Rafinesque’s names for western American mammals, including the earliest scientific name for the coyote (Canis latrans Say, 1822), based on the apocryphal journal of Charles Le Raye

    USGS Publications Warehouse

    Woodman, Neal

    2015-01-01

    In 1817, the naturalist Constantine S. Rafinesque named nine new species of mammals from the American West, indicating the recently published journal of Charles Le Raye as the primary source for his descriptions. Le Raye was purported to be a French Canadian fur trader who, as a captive of the Sioux, had traveled across broad portions of the Missouri and Yellowstone river drainages a few years before the Lewis and Clark Expedition (1804-1806) traversed much of the same region. Le Raye's journal was relied upon by generations of scholars as a valuable source documenting the native peoples and natural history of the Upper Missouri river in the era just prior to European settlement. Subsequent research, however, has shown that Le Raye never existed, and his purported journal is fraudulent. Despite this, Rafinesque's creation of the names followed conventional and accepted practice at the time, and they are porentially available. Fortunately, much of the Le Raye journal was based on verifiable sources, such as Patrick Gass's published account of the Lewis and Clark Expedition. Identification of the original source materials makes it possible to establish the correct application of Rafinesque's names and to determine their current status. This process reveals that the earliest scientific name for the coyote (Canis latrans Say, 1822) was Canis chlorops Rafinesque, 1817; this name is now a nomen oblitum, however, and is no longer available.

  20. The right to life

    PubMed Central

    Boyd, Kenneth M

    1981-01-01

    For much of human history the idea of a right to life has not seemed self-evident. The credibility of the idea appears to depend on a particular kind of intuition concerning the nature of the world. In this paper, the kind of intuition involved is related to the idea of a covenant, illustrated by that of marriage. The paper concludes by suggesting that talk about responsibilities may be more fruitful than talk about rights. PMID:7277408

  1. Natural Xanthones

    NASA Astrophysics Data System (ADS)

    Denisova-Dyatlova, O. A.; Glyzin, V. I.

    1982-10-01

    The available information on the abundance of natural xanthones in nature and the methods for the determination of their structure, biogenesis, and pharmacological properties is surveyed and described systematically. The bibliography includes 151 references.

  2. The Promise of Quality of Life

    ERIC Educational Resources Information Center

    Peruniak, Geoffrey S.

    2008-01-01

    Little has been written in the career development literature about quality of life, even though this concept is implied in all counselor interventions. In this article, the author suggests that the broad and subjective nature of quality of life, rather than a liability, is its very strength. Quality of life is presented as an important holistic…

  3. Discovery of a Natural Microsporidian Pathogen with a Broad Tissue Tropism in Caenorhabditis elegans

    PubMed Central

    Luallen, Robert J.; Reinke, Aaron W.; Tong, Linda; Botts, Michael R.; Félix, Marie-Anne; Troemel, Emily R.

    2016-01-01

    Microbial pathogens often establish infection within particular niches of their host for replication. Determining how infection occurs preferentially in specific host tissues is a key aspect of understanding host-microbe interactions. Here, we describe the discovery of a natural microsporidian parasite of the nematode Caenorhabditis elegans that displays a unique tissue tropism compared to previously described parasites of this host. We characterize the life cycle of this new species, Nematocida displodere, including pathogen entry, intracellular replication, and exit. N. displodere can invade multiple host tissues, including the epidermis, muscle, neurons, and intestine of C. elegans. Despite robust invasion of the intestine very little replication occurs there, with the majority of replication occurring in the muscle and epidermis. This feature distinguishes N. displodere from two closely related microsporidian pathogens, N. parisii and N. sp. 1, which exclusively invade and replicate in the intestine. Comparison of the N. displodere genome with N. parisii and N. sp. 1 reveals that N. displodere is the earliest diverging species of the Nematocida genus. Over 10% of the proteins encoded by the N. displodere genome belong to a single species-specific family of RING-domain containing proteins of unknown function that may be mediating interactions with the host. Altogether, this system provides a powerful whole-animal model to investigate factors responsible for pathogen growth in different tissue niches. PMID:27362540

  4. Discovering Nature with Young Children.

    ERIC Educational Resources Information Center

    Chalufour, Ingrid; Worth, Karen

    Young children's curiosity about nature and their need to make sense of the world presents an opportunity to incorporate science as a natural and critical part of children's early learning. This guide, part of a preschool science curriculum, uses an inquiry approach to encourage young naturalists to observe life more closely, build an…

  5. Earliest Evidence of Toxocara sp. in a 1.2-Million-Yr-Old Extinct Hyena (Pachycrocuta brevirostris) Coprolite from Northwest Pakistan.

    PubMed

    Perri, Angela R; Heinrich, Susann; Gur-Arieh, Shira; Saunders, Jeffrey J

    2017-02-01

    The study of fossil parasites can provide insight into the antiquity of host-parasite relationships and the origins and evolution of these paleoparasites. Here, a coprolite (fossilized feces) from the 1.2-million-yr-old paleontological site of Haro River Quarry in northwestern Pakistan was analyzed for paleoparasites. Micromorphological thin sectioning and Fourier-transform infrared spectrometry (FTIR) analysis confirms the coprolite belonged to a bone-eating carnivore, likely the extinct giant short-faced hyena (Pachycrocuta brevirostris). Parasitological analysis shows the coprolite to be positive for Toxocara sp. To our knowledge, this is the earliest evidence for Toxocara sp. found.

  6. Life sciences and space research XXIV(4) - Natural and artificial ecosystems; Proceedings of the Topical Meeting of the Interdisciplinary Scientific Commission F (Meetings F10, F11, F1 and F12) of the COSPAR 28th Plenary Meeting, The Hague, Netherlands, June 25-July 6, 1990

    NASA Technical Reports Server (NTRS)

    Macelroy, R. D. (Editor); Averner, M. M. (Editor); Tibbits, T. W. (Editor); Bugbee, B. B. (Editor); Horneck, G. (Editor); Dunlop, E. H. (Editor)

    1992-01-01

    The present conference on natural and artificial ecosystems and their application to space research encompasses both in-flight and ground-based issues of recycling and control in regenerative life support, the relationships of productivity and facility design in higher plant growth, life-support systems for manned missions to Mars, and biochemical engineering applications in space. Specific issues addressed include interface problems between material recycling systems and plants, temperature and humidity control on a lunar base, the CELSS Test-Facility Project, achieving closure in plant-growth facilities, and life-support systems for Mars transit. Also addressed are a closed equilibrated biological aquatic system, a simulated Mars outpost in the Antarctica dry valleys, analyses of human kidney-cell populations separated on the space shuttle, and the evolution of a phase-separated gravity-independent bioreactor.

  7. Life-threatening bleeding from gastric mucosal angiokeratomas during anticoagulation

    PubMed Central

    Kang, Eungu; Kim, Yoon-Myung; Kim, Dae-Hee; Yoo, Han-Wook; Lee, Beom Hee

    2017-01-01

    Abstract Rationale: Angiokeratomas are the earliest manifestation of Fabry disease (FD), and the extent of their appearance is related to disease severity. Angiokeratomas are mostly found on cutaneous regions. Patient concerns, diagnoses, interventions, and outcomes: Here we report an FD patient with widespread gastrointestinal angiokeratomas who developed life-threatening bleeding following anticoagulation for atrial fibrillation. Lessons: Careful observation for gastrointestinal bleeding is warranted for patients on anticoagulation with extensive cutaneous angiokeratomas. Furthermore, our experience suggests that surveillance is needed to assess the prevalence and extent of gastrointestinal angiokeratomas in patients with FD. PMID:28178158

  8. Lake Life.

    ERIC Educational Resources Information Center

    Ohrn, Deborah Gore, Ed.

    1993-01-01

    This quarterly publication of the State Historical Society of Iowa features articles and activities for elementary school students. This summer issue focuses on the topic of lake life. The issue includes the following features: (1) "Where the Lakes Are Map"; (2) "Letter from the Lake"; (3) "Lake People"; (4)…

  9. Life sciences.

    PubMed

    Martin-Brennan, Cindy; Joshi, Jitendra

    2003-12-01

    Space life sciences research activities are reviewed for 2003. Many life sciences experiments were lost with the tragic loss of STS-107. Life sciences experiments continue to fly as small payloads to the International Space Station (ISS) via the Russian Progress vehicle. Health-related studies continue with the Martian Radiation Environment Experiment (MARIE) aboard the Odyssey spacecraft, collecting data on the radiation environment in Mars orbit. NASA Ames increased nanotechnology research in all areas, including fundamental biology, bioastronautics, life support systems, and homeland security. Plant research efforts continued at NASA Kennedy, testing candidate crops for ISS. Research included plant growth studies at different light intensities, varying carbon dioxide concentrations, and different growth media. Education and outreach efforts included development of a NASA/USDA program called Space Agriculture in the Classroom. Canada sponsored a project called Tomatosphere, with classrooms across North America exposing seeds to simulated Mars environment for growth studies. NASA's Office of Biological and Physical Research released an updated strategic research plan.

  10. Magnetic resonance study of the influence of tissue damage and cortical reorganization on PASAT performance at the earliest stage of multiple sclerosis.

    PubMed

    Audoin, Bertrand; Au Duong, My Van; Ranjeva, Jean-Philippe; Ibarrola, Danielle; Malikova, Irina; Confort-Gouny, Sylviane; Soulier, Elisabeth; Viout, Patrick; Ali-Chérif, André; Pelletier, Jean; Cozzone, Patrick J

    2005-03-01

    We sought to determine the influence of tissue damage and the potential impact of cortical reorganization on the performance to the Paced Auditory Serial Addition Test (PASAT) in patients at the earliest stage of multiple sclerosis (MS). Magnetization transfer ratio (MTR) imaging and functional magnetic resonance imaging (fMRI) experiments using PASAT as paradigm were carried out in 18 patients with clinically isolated syndrome suggestive of MS (CISSMS) compared to 18 controls. MTR histogram analyses showed structural abnormalities in patients involving the normal-appearing white matter (NAWM) but also the gray matter (GM). Mean PASAT scores were significantly lower in the group of patients taken as a whole, and were correlated with the mean NAWM MTR value. No correlation was observed between PASAT scores and GM MTR. However, in the subgroup of patients with normal PASAT performance (n = 9), fMRI showed larger activations in bilateral Brodmann area 45 (BA45) and right BA44 compared to that in controls (n = 18). In these areas with potentially compensatory reorganization, the whole group of patients (n = 18) showed significantly greater activation than controls (n = 18). Activation in the right BA45 was inversely correlated with the mean NAWM MTR and the peak position of GM MTR histograms of patients. This study indicates that even at the earliest stage of MS, cortical reorganization is present inside the executive system of working memory and could tend to limit the determinant functional impact of NAWM injury on the execution of the PASAT.

  11. Earliest floral grave lining from 13,700-11,700-y-old Natufian burials at Raqefet Cave, Mt. Carmel, Israel.

    PubMed

    Nadel, Dani; Danin, Avinoam; Power, Robert C; Rosen, Arlene M; Bocquentin, Fanny; Tsatskin, Alexander; Rosenberg, Danny; Yeshurun, Reuven; Weissbrod, Lior; Rebollo, Noemi R; Barzilai, Omry; Boaretto, Elisabetta

    2013-07-16

    Flowering plants possess mechanisms that stimulate positive emotional and social responses in humans. It is difficult to establish when people started to use flowers in public and ceremonial events because of the scarcity of relevant evidence in the archaeological record. We report on uniquely preserved 13,700-11,700-y-old grave linings made of flowers, suggesting that such use began much earlier than previously thought. The only potentially older instance is the questionable use of flowers in the Shanidar IV Neanderthal grave. The earliest cemeteries (ca. 15,000-11,500 y ago) in the Levant are known from Natufian sites in northern Israel, where dozens of burials reflect a wide range of inhumation practices. The newly discovered flower linings were found in four Natufian graves at the burial site of Raqefet Cave, Mt. Carmel, Israel. Large identified plant impressions in the graves include stems of sage and other Lamiaceae (Labiatae; mint family) or Scrophulariaceae (figwort family) species; accompanied by a plethora of phytoliths, they provide the earliest direct evidence now known for such preparation and decoration of graves. Some of the plant species attest to spring burials with a strong emphasis on colorful and aromatic flowers. Cave floor chiseling to accommodate the desired grave location and depth is also evident at the site. Thus, grave preparation was a sophisticated planned process, embedded with social and spiritual meanings reflecting a complex preagricultural society undergoing profound changes at the end of the Pleistocene.

  12. Earliest floral grave lining from 13,700–11,700-y-old Natufian burials at Raqefet Cave, Mt. Carmel, Israel

    PubMed Central

    Nadel, Dani; Danin, Avinoam; Power, Robert C.; Rosen, Arlene M.; Bocquentin, Fanny; Tsatskin, Alexander; Rosenberg, Danny; Yeshurun, Reuven; Weissbrod, Lior; Rebollo, Noemi R.; Barzilai, Omry; Boaretto, Elisabetta

    2013-01-01

    Flowering plants possess mechanisms that stimulate positive emotional and social responses in humans. It is difficult to establish when people started to use flowers in public and ceremonial events because of the scarcity of relevant evidence in the archaeological record. We report on uniquely preserved 13,700–11,700-y-old grave linings made of flowers, suggesting that such use began much earlier than previously thought. The only potentially older instance is the questionable use of flowers in the Shanidar IV Neanderthal grave. The earliest cemeteries (ca. 15,000–11,500 y ago) in the Levant are known from Natufian sites in northern Israel, where dozens of burials reflect a wide range of inhumation practices. The newly discovered flower linings were found in four Natufian graves at the burial site of Raqefet Cave, Mt. Carmel, Israel. Large identified plant impressions in the graves include stems of sage and other Lamiaceae (Labiatae; mint family) or Scrophulariaceae (figwort family) species; accompanied by a plethora of phytoliths, they provide the earliest direct evidence now known for such preparation and decoration of graves. Some of the plant species attest to spring burials with a strong emphasis on colorful and aromatic flowers. Cave floor chiseling to accommodate the desired grave location and depth is also evident at the site. Thus, grave preparation was a sophisticated planned process, embedded with social and spiritual meanings reflecting a complex preagricultural society undergoing profound changes at the end of the Pleistocene. PMID:23818584

  13. The Servol Life Centres.

    ERIC Educational Resources Information Center

    Pantin, Gerard

    This publication summarizes the evolution of the basic ideas and philosophies of a community development organization called Servol in Trinidad and recounts how over nine years these ideas coalesced into a unified approach. The document describes how the earliest projects--a welding institute, a clinic, a nursery school, and recreational…

  14. The value of life and the value of life extension.

    PubMed

    Horrobin, Steven

    2006-05-01

    Recent developments in aging research have added new urgency to the bioethical debate concerning life and death issues, the value of life, and the reasonable limits of medicine. This paper analyzes the basic structures of the liberal and conservative components of this debate, showing that there has hitherto been inadequate analysis on both sides concerning the nature and implications of the value of life, as well as, and as distinct from the value of life extension. Classic concepts of the intrinsic or extrinsic value of life are argued to be tangential or actually irrelevant to the value of life's continuance and so to the value of life extension. An analysis of personhood is proposed which focuses explicitly upon the value of life extension to persons. This analysis shows that persons may only intelligibly be understood as processes, for whom life extension is an inalienable and fundamental value. It is further proposed that, properly understood, such an analysis may significantly narrow the liberal/conservative divide in bioethics.

  15. Cosmic life

    NASA Astrophysics Data System (ADS)

    Friedman, H.

    1980-01-01

    The existence and detection of extraterrestrial life are discussed. The evolution of life on earth is not considered possible if earth were 5% closer (runaway greenhouse effect) or 1% farther (runaway glaciation) from the sun, or if the sun were slightly more or less massive or hot. The Space Telescope and a possible interferometer search at infrared wavelengths, which offers a 100,000 times advantage over the visible in the ratio of planetary to stellar power, are proposed to help detect planetary systems about stars such as Barnard's star. The proposed NASA-Ames Project Cyclops, consisting of a 10 km phased array of 1026 dishes (perhaps on the back side of the moon), as well as a Soviet proposal to assemble 2 similar telescopes at the orbit of Saturn, would search in the radio frequency range for planets 100 light years or more distant.

  16. Where is Extraterrestrial Life Likely to be Found

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  17. Origin and evolution of life on terrestrial planets.

    PubMed

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

    2010-01-01

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

  18. Natural pigments and sacred art

    NASA Astrophysics Data System (ADS)

    Kelekian, Lena, ,, Lady

    2010-05-01

    Since the dawn of mankind, cavemen has expressed himself through art. The earliest known cave paintings date to some 32,000 years ago and used 4 colours derived from the earth. These pigments were iron oxides and known as ochres, blacks and whites. All pigments known by the Egyptians, the Greeks, the Romans and Renaissance man were natural and it was not until the 18th century that synthetic pigments were made and widely used. Until that time all art, be it sacred or secular used only natural pigments, of which the preparation of many have been lost or rarely used because of their tedious preparation. As a geologist, a mineralogist and an artist specializing in iconography, I have been able to rediscover 89 natural pigments extracted from minerals. I use these pigments to paint my icons in the traditional Byzantine manner and also to restore old icons, bringing back their glamour and conserving them for years to come. The use of the natural pigments in its proper way also helps to preserve the traditional skills of the iconographer. In the ancient past, pigments were extremely precious. Many took an exceedingly long journey to reach the artists, and came from remote countries. Research into these pigments is the work of history, geography and anthropology. It is an interesting journey in itself to discover that the blue aquamarines came from Afghanistan, the reds from Spain, the greens Africa, and so on. In this contribution I will be describing the origins, preparation and use of some natural pigments, together with their history and provenance. Additionally, I will show how the natural pigments are used in the creation of an icon. Being a geologist iconographer, for me, is a sacrement that transforms that which is earthly, material and natural into a thing of beauty that is sacred. As bread and wine in the Eucharist, water during baptism and oil in Holy Union transmit sanctification to the beholder, natural pigments do the same when one considers an icon. The

  19. Natural Beauty

    ERIC Educational Resources Information Center

    Coy, Mary

    2006-01-01

    In this article, the author describes how her art class students were able to create, in just four class periods, clay relief plaques depicting nature. A lesson on texture speeds up the completion of such a project. Seeing that clay is a natural material with its own unique texture, it seemed fitting that the final product should depict a variety…

  20. Firsthand Nature

    ERIC Educational Resources Information Center

    Gostev, Moses; Weiss, Francesca Michaelides

    2007-01-01

    It's no secret that many school programs don't give children enough opportunity to explore the natural world--i.e., to "mess about" and to have firsthand experience with nature and animals. Not so at the Muscota New School in New York City! This innovative public elementary school actively promotes inquiry-based learning and encourages…