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Sample records for early planetesimals evidence

  1. Planetesimals early differentiation and consequences for planets

    CERN Document Server

    Weiss, Benjamin P

    2017-01-01

    Processes governing the evolution of planetesimals are critical to understanding how rocky planets are formed, how water is delivered to them, the origin of planetary atmospheres, how cores and magnetic dynamos develop, and ultimately, which planets have the potential to be habitable. Theoretical advances and new data from asteroid and meteorite observations, coupled with spacecraft missions such as Rosetta and Dawn, have led to major advances in this field over the last decade. This transdisciplinary volume presents an authoritative overview of the latest in our understanding of the processes of planet formation. Combining meteorite, asteroid and icy body observations with theory and modelling of accretion and orbital dynamics, this text also provides insights into the exoplanetary system and the search for habitable worlds. This is an essential reference for those interested in planetary formation, solar system dynamics, exoplanets and planetary habitability.

  2. Paleomagnetic evidence for a partially differentiated H chondrite parent planetesimal

    Science.gov (United States)

    Bryson, J. F. J.; Weiss, B. P.; Scholl, A.; Getzin, B. L.; Abrahams, J. N. H.; Nimmo, F.

    2016-12-01

    The texture, composition and ages of chondrites have all been used to argue that the parent bodies of these meteorites did not undergo planetary differentiation. Without a core, these planetesimals could not have generated planetary magnetic fields, hence chondrites are predicted to be unmagnetized. Here, we test this hypothesis by applying synchrotron x-ray microscopy to the metallic melt veins in the metamorphosed H chondrite breccia Portales Valley. We find that tetrataenite nanostructures in these veins are uniformly magnetized, suggesting that the H chondrite parent body generated a stable, 10 µT ancient field. We also performed alternating field (AF) demagnetization on bulk silicate-rich portions of Portales Valley, finding that both the large grain size of the metal in these subsamples and the presence of tetrataenite hinder the reliable interpretation of these measurements. Based on 40Ar/39Ar dating and the metallographic cooling rate, we propose that this field inferred from x-ray microscopy was generated 100 Myr after solar system formation and lasted >5 Myr. These properties are consistent with a dynamo field generated by core solidification, implying that the H chondrite parent body was partially differentiated. This conclusion is supported by our analyses of the H4 chondrite Forest Vale, which show that H chondrite magnetization is unlikely to be a relic signature of early nebular or solar wind fields (Getzin et al., this meeting; Oran et al., this meeting). We propose that partial differentiation could result form prolonged accretion over millions of years, possibly in two stages. In this scenario, the earliest accreted material melted from the radioactive decay of abundant 26Al, forming a core and rocky achondritic mantle, while the later accreted material was less metamorphosed, forming an undifferentiated crust. We demonstrate that, with the inclusion of an insulating regolith, the thermal evolution of such a body is consistent with the measured

  3. Early planetesimal melting from an age of 4.5662 Gyr for differentiated meteorites

    DEFF Research Database (Denmark)

    Baker, J.; Bizzarro, Martin; Wittig, N.

    2005-01-01

    for these meteorites, however, are typically younger than age constraints for planetesimal differentiation. Such young ages indicate that the energy required to melt their parent bodies could not have come from the most likely heat source-radioactive decay of short-lived nuclides (Al and Fe) injected from a nearby...... decay could have triggered planetesimal melting. Small Mg excesses in bulk angrite samples confirm that Al decay contributed to the melting of their parent body. These results indicate that the accretion of differentiated planetesimals pre-dated that of undifferentiated planetesimals, and reveals......Long- and short-lived radioactive isotopes and their daughter products in meteorites are chronometers that can test models for Solar System formation. Differentiated meteorites come from parent bodies that were once molten and separated into metal cores and silicate mantles. Mineral ages...

  4. Magnesium isotope evidence for single stage formation of CB chondrules by colliding planetesimals

    DEFF Research Database (Denmark)

    Olsen, Mia Bjørg Stolberg; Schiller, Martin; Krot, Alexander N.

    2013-01-01

    Chondrules are igneous spherical objects preserved in chondritic meteorites and believed to have formed during transient heating events in the solar protoplanetary disk. Chondrules present in the metal-rich CB chondrites show unusual chemical and petrologic features not observed in other chondrit...... planetesimals. The inferred μMg* value of -3.87 ± 0.93 ppm for the CB parent body is significantly lower than the bulk solar system value of 4.5 ± 1.1 ppm inferred from CI chondrites, suggesting that CB chondrites accreted material comprising an early formed Al-free component.......Chondrules are igneous spherical objects preserved in chondritic meteorites and believed to have formed during transient heating events in the solar protoplanetary disk. Chondrules present in the metal-rich CB chondrites show unusual chemical and petrologic features not observed in other chondrite......, indicating substantial suppression of isotopic fractionation during evaporative loss of Mg, possibly due to evaporation at high Mg partial pressure. Thus, the Mg-isotope data of skeletal chondrules from HH237 are consistent with their origin as melts produced in the impact-generated plume of colliding...

  5. Particle Size Distributions in Chondritic Meteorites: Evidence for Pre-Planetesimal Histories

    Science.gov (United States)

    Simon, J. I.; Cuzzi, J. N.; McCain, K. A.; Cato, M. J.; Christoffersen, P. A.; Fisher, K. R.; Srinivasan, P.; Tait, A. W.; Olson, D. M.; Scargle, J. D.

    2018-01-01

    Magnesium-rich silicate chondrules and calcium-, aluminum-rich refractory inclusions (CAIs) are fundamental components of primitive chondritic meteorites. It has been suggested that concentration of these early-formed particles by nebular sorting processes may lead to accretion of planetesimals, the planetary bodies that represent the building blocks of the terrestrial planets. In this case, the size distributions of the particles may constrain the accretion process. Here we present new particle size distribution data for Northwest Africa 5717, a primitive ordinary chondrite (ungrouped 3.05) and the well-known carbonaceous chondrite Allende (CV3). Instead of the relatively narrow size distributions obtained in previous studies (Ebel et al., 2016; Friedrich et al., 2015; Paque and Cuzzi, 1997, and references therein), we observed broad size distributions for all particle types in both meteorites. Detailed microscopic image analysis of Allende shows differences in the size distributions of chondrule subtypes, but collectively these subpopulations comprise a composite "chondrule" size distribution that is similar to the broad size distribution found for CAIs. Also, we find accretionary 'dust' rims on only a subset (approximately 15-20 percent) of the chondrules contained in Allende, which indicates that subpopulations of chondrules experienced distinct histories prior to planetary accretion. For the rimmed subset, we find positive correlation between rim thickness and chondrule size. The remarkable similarity between the size distributions of various subgroups of particles, both with and without fine grained rims, implies a common size sorting process. Chondrite classification schemes, astrophysical disk models that predict a narrow chondrule size population and/or a common localized formation event, and conventional particle analysis methods must all be critically reevaluated. We support the idea that distinct "lithologies" in NWA 5717 are nebular aggregates of

  6. The Acapulco Parent Planetesimal: An Early Collisional History in the Solar System

    Science.gov (United States)

    Marti, K.; Kim, Y.

    2007-05-01

    The Acapulco, Mexico, meteorite was recovered in 1976 from a crater of approx. 30 cm diameter. An old crystallization age of 4.60 (error 0.03) Ga (Prinzhofer et al., 1992) establishes that its parent object is one of the oldest known planetesimals in the solar system, although not in a pristine form. Other dating systems indicated somewhat younger ages and isotopic variabilities in several elements documented a complex early history. The younger ages date the closure times in secondary minerals. The initial parent object was in a partially molten state when isotopically distinct foreign matter invaded the chondritic parent and some of the isotopic signatures survived. Nitrogen in the primitive achondrite Acapulco was found to have distinct isotopic signatures for the metal and silicate phases and also in different morphologies of graphites (El Goresy, 1995, 2005). The delayed collisional event probably disrupted the parent object, as Acapulco cooled very rapidly. Nitrogen in the injected metal and graphite did not isotopically exchange with the host silicates. We observed nitrogen isotopic signatures of several separated mineral phases which cover a range of delta 15N values from -150 permil to +13 permil. The lightest nitrogen signatures observed in metal separates are comparable to those in some morphologies of Acapulco graphites. The heavy N signatures observed in several silicate minerals are consistent with each other, while nitrogen in chromite is distinctly light (delta 15N of -80 permil), intermediate between those of metal and silicates. The incipient rapid cooling history is well documented down to approx. 120° C, as recorded by U/Th-4He ages in phosphates (Min et al., 2003). The history of the Acapulco parent object was uneventful after its early evolution in an environment where no perturbation by collisions occurred, until the meteorite's recent (6.0 Ma ago) injection into an earth-crossing orbit. References: El Goresy, A., Zinner, E., and Marti, K

  7. ROCKY PLANETESIMAL FORMATION VIA FLUFFY AGGREGATES OF NANOGRAINS

    Energy Technology Data Exchange (ETDEWEB)

    Arakawa, Sota; Nakamoto, Taishi, E-mail: arakawa.s.ac@m.titech.ac.jp [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro, Tokyo 152-8551 (Japan)

    2016-12-01

    Several pieces of evidence suggest that silicate grains in primitive meteorites are not interstellar grains but condensates formed in the early solar system. Moreover, the size distribution of matrix grains in chondrites implies that these condensates might be formed as nanometer-sized grains. Therefore, we propose a novel scenario for rocky planetesimal formation in which nanometer-sized silicate grains are produced by evaporation and recondensation events in early solar nebula, and rocky planetesimals are formed via aggregation of these nanograins. We reveal that silicate nanograins can grow into rocky planetesimals via direct aggregation without catastrophic fragmentation and serious radial drift, and our results provide a suitable condition for protoplanet formation in our solar system.

  8. The effects of short-lived radionuclides and porosity on the early thermo-mechanical evolution of planetesimals

    Science.gov (United States)

    Lichtenberg, Tim; Golabek, Gregor J.; Gerya, Taras V.; Meyer, Michael R.

    2016-08-01

    The thermal history and internal structure of chondritic planetesimals, assembled before the giant impact phase of chaotic growth, potentially yield important implications for the final composition and evolution of terrestrial planets. These parameters critically depend on the internal balance of heating versus cooling, which is mostly determined by the presence of short-lived radionuclides (SLRs), such as 26Al and 60Fe, as well as the heat conductivity of the material. The heating by SLRs depends on their initial abundances, the formation time of the planetesimal and its size. It has been argued that the cooling history is determined by the porosity of the granular material, which undergoes dramatic changes via compaction processes and tends to decrease with time. In this study we assess the influence of these parameters on the thermo-mechanical evolution of young planetesimals with both 2D and 3D simulations. Using the code family I2ELVIS/I3ELVIS we have run numerous 2D and 3D numerical finite-difference fluid dynamic models with varying planetesimal radius, formation time and initial porosity. Our results indicate that powdery materials lowered the threshold for melting and convection in planetesimals, depending on the amount of SLRs present. A subset of planetesimals retained a powdery surface layer which lowered the thermal conductivity and hindered cooling. The effect of initial porosity was small, however, compared to those of planetesimal size and formation time, which dominated the thermo-mechanical evolution and were the primary factors for the onset of melting and differentiation. We comment on the implications of this work concerning the structure and evolution of these planetesimals, as well as their behavior as possible building blocks of terrestrial planets.

  9. PLANETESIMAL DISK MICROLENSING

    International Nuclear Information System (INIS)

    Heng, Kevin; Keeton, Charles R.

    2009-01-01

    Motivated by debris disk studies, we investigate the gravitational microlensing of background starlight by a planetesimal disk around a foreground star. We use dynamical survival models to construct a plausible example of a planetesimal disk and study its microlensing properties using established ideas of microlensing by small bodies. When a solar-type source star passes behind a planetesimal disk, the microlensing light curve may exhibit short-term, low-amplitude residuals caused by planetesimals several orders of magnitude below Earth mass. The minimum planetesimal mass probed depends on the photometric sensitivity and the size of the source star, and is lower when the planetesimal lens is located closer to us. Planetesimal lenses may be found more nearby than stellar lenses because the steepness of the planetesimal mass distribution changes how the microlensing signal depends on the lens/source distance ratio. Microlensing searches for planetesimals require essentially continuous monitoring programs that are already feasible and can potentially set constraints on models of debris disks, the progeny of the supposed extrasolar analogues of Kuiper Belts.

  10. The multifaceted planetesimal formation process

    DEFF Research Database (Denmark)

    Johansen, Anders; Blum, Jürgen; Tanaka, Hidekazu

    2013-01-01

    Accumulation of dust and ice particles into planetesimals is an important step in the planet formation process. Planetesimals are the seeds of both terrestrial planets and the solid cores of gas and ice giants forming by core accretion. Left-over planetesimals in the form of asteroids, trans...... for planetesimal formation where particle growth starts unaided by self-gravity but later proceeds inside gravitationally collapsing pebble clumps to form planetesimals with a wide range of sizes....

  11. Planetesimals and Planet Formation

    Science.gov (United States)

    Chambers, John

    The first step in the standard model for planet formation is the growth of gravitationally bound bodies called ``planetesimals'' from dust grains in a protoplanetary disk. Currently, we do not know how planetesimals form, how long they take to form, or what their sizes and mechanical properties are. The goal of this proposal is to assess how these uncertainties affect subsequent stages of planetary growth and the kind of planetary systems that form. The work will address three particular questions: (i) Can the properties of small body populations in the modern Solar System constrain the properties of planetesimals? (ii) How do the properties of planetesimals affect the formation of giant planets? (iii) How does the presence of a water ice condensation front (the ``snow line'') in a disk affect planetesimal formation and the later stages of planetary growth? These questions will be examined with computer simulations of planet formation using new computer codes to be developed as part of the proposal. The first question will be addressed using a statistical model for planetesimal coagulation and fragmentation. This code will be merged with the proposer's Mercury N-body integrator code to model the dynamics of large protoplanets in order to address the second question. Finally, a self- consistent model of disk evolution and the radial transport of water ice and vapour will be added to examine the third question. A theoretical understanding of how planets form is one of the key goals of NASA and the Origins of Solar Systems programme. Researchers have carried out many studies designed to address this goal, but the questions of how planetesimals form and how their properties affect planet formation have received relatively little attention. The proposed work will help address these unsolved questions, and place other research in context by assessing the importance of planetesimal origins and properties for planet formation.

  12. Planetesimal Formation by the Streaming Instability in a Photoevaporating Disk

    Energy Technology Data Exchange (ETDEWEB)

    Carrera, Daniel; Johansen, Anders; Davies, Melvyn B. [Lund Observatory, Dept. of Astronomy and Theoretical Physics, Lund University, Box 43, SE-221 00 Lund (Sweden); Gorti, Uma [NASA Ames Research Center, Moffett Field, CA (United States)

    2017-04-10

    Recent years have seen growing interest in the streaming instability as a candidate mechanism to produce planetesimals. However, these investigations have been limited to small-scale simulations. We now present the results of a global protoplanetary disk evolution model that incorporates planetesimal formation by the streaming instability, along with viscous accretion, photoevaporation by EUV, FUV, and X-ray photons, dust evolution, the water ice line, and stratified turbulence. Our simulations produce massive (60–130 M {sub ⊕}) planetesimal belts beyond 100 au and up to ∼20 M {sub ⊕} of planetesimals in the middle regions (3–100 au). Our most comprehensive model forms 8 M {sub ⊕} of planetesimals inside 3 au, where they can give rise to terrestrial planets. The planetesimal mass formed in the inner disk depends critically on the timing of the formation of an inner cavity in the disk by high-energy photons. Our results show that the combination of photoevaporation and the streaming instability are efficient at converting the solid component of protoplanetary disks into planetesimals. Our model, however, does not form enough early planetesimals in the inner and middle regions of the disk to give rise to giant planets and super-Earths with gaseous envelopes. Additional processes such as particle pileups and mass loss driven by MHD winds may be needed to drive the formation of early planetesimal generations in the planet-forming regions of protoplanetary disks.

  13. APPLICATION OF GAS DYNAMICAL FRICTION FOR PLANETESIMALS. II. EVOLUTION OF BINARY PLANETESIMALS

    Energy Technology Data Exchange (ETDEWEB)

    Grishin, Evgeni; Perets, Hagai B. [Physics Department, Technion—Israel Institute of Technology, Haifa, 3200003 (Israel)

    2016-04-01

    One of the first stages of planet formation is the growth of small planetesimals and their accumulation into large planetesimals and planetary embryos. This early stage occurs long before the dispersal of most of the gas from the protoplanetary disk. At this stage gas–planetesimal interactions play a key role in the dynamical evolution of single intermediate-mass planetesimals (m{sub p} ∼ 10{sup 21}–10{sup 25} g) through gas dynamical friction (GDF). A significant fraction of all solar system planetesimals (asteroids and Kuiper-belt objects) are known to be binary planetesimals (BPs). Here, we explore the effects of GDF on the evolution of BPs embedded in a gaseous disk using an N-body code with a fiducial external force accounting for GDF. We find that GDF can induce binary mergers on timescales shorter than the disk lifetime for masses above m{sub p} ≳ 10{sup 22} g at 1 au, independent of the binary initial separation and eccentricity. Such mergers can affect the structure of merger-formed planetesimals, and the GDF-induced binary inspiral can play a role in the evolution of the planetesimal disk. In addition, binaries on eccentric orbits around the star may evolve in the supersonic regime, where the torque reverses and the binary expands, which would enhance the cross section for planetesimal encounters with the binary. Highly inclined binaries with small mass ratios, evolve due to the combined effects of Kozai–Lidov (KL) cycles with GDF which lead to chaotic evolution. Prograde binaries go through semi-regular KL evolution, while retrograde binaries frequently flip their inclination and ∼50% of them are destroyed.

  14. Pebble pile-up and planetesimal formation at the snow line

    Science.gov (United States)

    Drazkowska, J.

    2017-09-01

    The planetesimal formation stage represents a major gap in our understanding of planet formation process. Because of this, the late-stage planet accretion models typically make arbitrary assumptions about planetesimals and pebbles distribution, while the state-of-the-art dust evolution models predict no or little planetesimal formation. With this contribution, I present a step toward bridging the gap between the early and late stages of planet formation by models that connect dust coagulation and planetesimal formation. With the aid of evaporation, outward diffusion, and re-condensation of water vapor, pile-up of large pebbles is formed outside of the snow line that facilitates planetesimal formation by streaming instability.

  15. Evidence favoring an internally generated dynamo in the H chondrite parent planetesimal from the Forest Vale meteorite

    Science.gov (United States)

    Getzin, B. L.; Bryson, J. F. J.; Weiss, B. P.; Gattacceca, J.

    2016-12-01

    Chondritic meteorites are traditionally assumed to originate from undifferentiated asteroids due to their unmelted texture and composition. This implies that their parent bodies should not have formed a core or generated a dynamo. However, recent measurements of the H chondrite Portales Valley (Bryson et al., this meeting) observed post-accretional remanent magnetization interpreted as a record of a core dynamo, indicating that some chondrite parent bodies were partially differentiated. However, it has been proposed that the H chondrites may have been magnetized instead by a crustal remanent field. If this crustal magnetization was imparted by an early external source, such as nebular fields or even the solar wind, then the magnetization of H chondrites may not require a core dynamo. To test this hypothesis, we measured the magnetic properties of the Forest Vale H4 ordinary chondrite. Forest Vale cooled quickly (10000 K/My) and so would have acquired magnetization that represents the bulk of the H chondrite parent body's crust during the first 10 My of the solar system. Based on alternating field and pressure demagnetization experiments of natural remanent magnetization (NRM) and anhysteretic remanent magnetization, we conclude that Forest Vale contains no ancient magnetization and, due to its poor intrinsic magnetic recording properties, is unable to acquire a magnetization that is stable against even weak shocks (0.2 GPa). Furthermore, we show that a crust composed of Forest-Vale-like material magnetized by the upper limit field intensities expected for the nebula and solar wind fields (50 μT and 1 μT, respectively) produces an insufficient crustal remanent field (<2.5 μT and <0.045 μT, respectively) to explain the paleointensity recorded by Portales Valley ( 10 μT). Thus, we conclude that the field that magnetization Portales Valley is unlikely to be from a crustal remanence magnetized by early external fields, favoring a partially differentiated asteroid

  16. The Physics of Planetesimal Formation

    Science.gov (United States)

    Simon, Jacob; Armitage, Philip; Youdin, Andrew; Li, Rixin

    2015-12-01

    Planetesimals are the precursors to planets, and understanding their formation is an essential step towards developing a complete theory of planet formation. For small solid particles (e.g., dust grains) to coagulate into planetesimals, however, requires that these particles grow beyond centimeter sizes; with traditional coagulation physics, this is very difficult. The streaming instability, which is a clumping process akin to the pile-up of cars in a traffic jam, generates sufficiently high solid densities that the mutual gravity between the clumped particles eventually causes their collapse towards planetesimal mass and size scales. Exploring this transition from dust grains to planetesimals is still in its infancy but is extremely important if we want to understand the basics of planet formation. Here, I present a series of high resolution, first principles numerical simulations of potoplanetary disk gas and dust to study the clumping of particles via the streaming instability and the subsequent collapse towards planetesimals. These simulations have been employed to characterize the planetesimal population as a function of radius in protoplanetary disks. The results of these simulations will be crucial for planet formation models to correctly explain the formation and configuration of solar systems.

  17. Xenon fractionation in porous planetesimals

    International Nuclear Information System (INIS)

    Zahnle, K.; Pollack, J.B.; Kasting, J.F.

    1990-01-01

    The distinctively fractionated Xe on Mars and Earth may have its root in a common source from which both planets accreted. We begin with Ozima and Nakazawa's hypothesis that terrestrial Xe fractionation was caused by gravitational separation of adsorbed solar nebular gases inside large porous planetesimals. We point out that Xe would have been trapped as the planetesimal grew and pores were squeezed shut by lithostatic pressure. We show that enough fractionated Xe to supply the Earth could have been trapped this way. The degree of fractionation is controlled by the lithostatic pressure at the pore-closing front and so would have been roughly the same for all large planetesimals. The predicted degree of fractionation agrees well with that preserved in terrestrial and martian Xe. Relative to Xe, this source is strongly depleted in other noble gases. In contrast to the original Ozima and Nakazawa hypothesis, our hypothesis predicts the observed fractionation, and it allows planetary accretion to occur after the dissipation of the solar nebula. The required planetesimals are large, representing a class of object now extinct in the solar system

  18. Planetesimals around nearby millisecond pulsars

    International Nuclear Information System (INIS)

    Chakrabarti, S.K.

    1992-05-01

    We predict that it is possible to observe line emissions of OH, CN and C 2 from the planetesimals around some of the nearby millisecond pulsars, such as PSR1257+12. Observation of these lines will provide an independent test of either an existing planetary system or one which is in the process of formation. (author). 11 refs, 1 tab

  19. Xenon fractionation in porous planetesimals

    Science.gov (United States)

    Zahnle, Kevin; Pollack, James B.; Kasting, James F.

    1990-01-01

    The distinctively fractionated Xe on Mars and earth may have its root in a common source from which both planets accreted. Beginning with Ozima and Nakazawa's (1980) hypothesis that terrestrial Xe fractionation was caused by gravitational separation of adsorbed solar nebular gases inside large porous planetesimals, it is pointed out that Xe would have been trapped as the planetesimal grew and pores were squeezed shut by lithostatic pressure. It is shown that enough fractionated Xe to supply the earth could have been trapped this way. The degree of fractionation is controlled by the lithostatic pressure at the pore-closing front and so would have been roughly the same for all large planetesimals. The predicted degree of fractionation agrees well with that preserved in terrestrial and Martian Xe. Relative to Xe, this source is strongly depleted in other noble gases. In contrast to the original Ozima and Nakazawa hypothesis, the present hypothesis predicts the observed fractionation, and it allows planetary accretion to occur after the dissipation of the solar nebula.

  20. Simulations of small solid accretion on to planetesimals in the presence of gas

    Science.gov (United States)

    Hughes, A. G.; Boley, A. C.

    2017-12-01

    The growth and migration of planetesimals in a young protoplanetary disc are fundamental to planet formation. In all models of early growth, there are several processes that can inhibit grains from reaching larger sizes. Nevertheless, observations suggest that growth of planetesimals must be rapid. If a small number of 100 km sized planetesimals do manage to form in the disc, then gas drag effects could enable them to efficiently accrete small solids from beyond their gravitationally focused cross-section. This gas-drag-enhanced accretion can allow planetesimals to grow at rapid rates, in principle. We present self-consistent hydrodynamics simulations with direct particle integration and gas-drag coupling to estimate the rate of planetesimal growth due to pebble accretion. Wind tunnel simulations are used to explore a range of particle sizes and disc conditions. We also explore analytic estimates of planetesimal growth and numerically integrate planetesimal drift due to the accretion of small solids. Our results show that, for almost every case that we consider, there is a clearly preferred particle size for accretion that depends on the properties of the accreting planetesimal and the local disc conditions. For solids much smaller than the preferred particle size, accretion rates are significantly reduced as the particles are entrained in the gas and flow around the planetesimal. Solids much larger than the preferred size accrete at rates consistent with gravitational focusing. Our analytic estimates for pebble accretion highlight the time-scales that are needed for the growth of large objects under different disc conditions and initial planetesimal sizes.

  1. Erosion and the limits to planetesimal growth

    Science.gov (United States)

    Krijt, S.; Ormel, C. W.; Dominik, C.; Tielens, A. G. G. M.

    2015-02-01

    Context. The coagulation of microscopic dust into planetesimals is the first step towards the formation of planets. The composition, size, and shape of the growing aggregates determine the efficiency of this early growth. In particular, it has been proposed that fluffy ice aggregates can grow very efficiently in protoplanetary disks, suffering less from the bouncing and radial drift barriers. Aims: While the collision velocity between icy aggregates of similar size is thought to stay below the fragmentation threshold, they may nonetheless lose mass from collisions with much smaller projectiles. As a result, erosive collisions have the potential to terminate the growth of pre-planetesimal bodies. We investigate the effect of these erosive collisions on the ability of porous ice aggregates to cross the radial drift barrier. Methods: We develop a Monte Carlo code that calculates the evolution of the masses and porosities of growing aggregates, while resolving the entire mass distribution at all times. The aggregate's porosity is treated independently of its mass, and is determined by collisional compaction, gas compaction, and eventually self-gravity compaction. We include erosive collisions and study the effect of the erosion threshold velocity on aggregate growth. Results: For erosion threshold velocities of 20-40 m s-1, high-velocity collisions with small projectiles prevent the largest aggregates from growing when they start to drift. In these cases, our local simulations result in a steady-state distribution, with most of the dust mass in particles with Stokes numbers close to unity. Only for the highest erosion threshold considered (60 m s-1) do porous aggregates manage to cross the radial drift barrier in the inner 10 AU of MMSN-like disks. Conclusions: Erosive collisions are more effective in limiting the growth than fragmentary collisions between similar-size particles. Conceivably, erosion limits the growth before the radial drift barrier, although the

  2. FROM DUST TO PLANETESIMAL: THE SNOWBALL PHASE?

    International Nuclear Information System (INIS)

    Xie Jiwei; Zhou Jilin; Payne, Matthew J.; Ge Jian; Thebault, Philippe

    2010-01-01

    The standard model of planet formation considers an initial phase in which planetesimals form from a dust disk, followed by a phase of mutual planetesimal-planetesimal collisions, leading eventually to the formation of planetary embryos. However, there is a potential transition phase (which we call the 'snowball phase'), between the formation of the first planetesimals and the onset of mutual collisions amongst them, which has often been either ignored or underestimated in previous studies. In this snowball phase, isolated planetesimals move in Keplerian orbits and grow solely via the direct accretion of subcentimeter-sized dust entrained with the gas in the protoplanetary disk. Using a simplified model in which planetesimals are progressively produced from the dust, we consider the expected sizes to which the planetesimals can grow before mutual collisions commence and derive the dependence of this size on a number of critical parameters, including the degree of disk turbulence, the planetesimal size at birth, and the rate of planetesimal creation. For systems in which turbulence is weak and the planetesimals are created at a low rate and with relatively small birth size, we show that the snowball growth phase can be very important, allowing planetesimals to grow by a factor of 10 6 in mass before mutual collisions take over. In such cases, the snowball growth phase can be the dominant mode to transfer mass from the dust to planetesimals. Moreover, such growth can take place within the typical lifetime of a protoplanetary gas disk. A noteworthy result is that, for a wide range of physically reasonable parameters, mutual collisions between planetesimals become significant when they reach sizes ∼100 km, irrespective of their birth size. This could provide an alternative explanation for the turnover point in the size distribution of the present-day asteroid belt. For the specific case of close binaries such as α Centauri, the role of snowball growth could be even

  3. Planetesimal formation starts at the snow line

    Science.gov (United States)

    Drążkowska, J.; Alibert, Y.

    2017-12-01

    Context. The formation stage of planetesimals represents a major gap in our understanding of the planet formation process. Late-stage planet accretion models typically make arbitrary assumptions about planetesimal and pebble distribution, while dust evolution models predict that planetesimal formation is only possible at some orbital distances. Aims: We wish to test the importance of the water snow line in triggering the formation of the first planetesimals during the gas-rich phase of a protoplanetary disk, when cores of giant planets have to form. Methods: We connected prescriptions for gas disk evolution, dust growth and fragmentation, water ice evaporation and recondensation, the transport of both solids and water vapor, and planetesimal formation via streaming instability into a single one-dimensional model for protoplanetary disk evolution. Results: We find that processes taking place around the snow line facilitate planetesimal formation in two ways. First, because the sticking properties between wet and dry aggregates change, a "traffic jam" inside of the snow line slows the fall of solids onto the star. Second, ice evaporation and outward diffusion of water followed by its recondensation increases the abundance of icy pebbles that trigger planetesimal formation via streaming instability just outside of the snow line. Conclusions: Planetesimal formation is hindered by growth barriers and radial drift and thus requires particular conditions to take place. The snow line is a favorable location where planetesimal formation is possible for a wide range of conditions, but not in every protoplanetary disk model, however. This process is particularly promoted in large cool disks with low intrinsic turbulence and an increased initial dust-to-gas ratio. The movie attached to Fig. 3 is only available at http://www.aanda.org

  4. Capture of Planetesimals into a Circumterrestrial Swarm

    Science.gov (United States)

    Weidenschilling, S. J.

    1985-01-01

    The lunar origin model considered in this report involves processing of protolunar material through a circumterrestrial swarm of particles. Once such a swarm has formed, it can gain mass by capturing infalling planetesimals and ejecta from giant impacts on the Earth, although the angular momentum supply from these sources remains a problem. The first stage of formation of a geocentric swarm by capture of planetesimals from initially heliocentric orbits is examined. The only plausible capture mechanism that is not dependent on very low approach velocities is the mutual collision of planetesimals passing within Earth's sphere of influence. The dissipation of energy in inelastic collisions or accretion events changes the value of the Jacobi parameter, allowing capture into bound geocentric orbits. This capture scenario was tested directly by many body numerical integration of planetesimal orbits in near Earth space.

  5. Debris disc constraints on planetesimal formation

    Science.gov (United States)

    Krivov, Alexander V.; Ide, Aljoscha; Löhne, Torsten; Johansen, Anders; Blum, Jürgen

    2018-02-01

    Two basic routes for planetesimal formation have been proposed over the last decades. One is a classical `slow-growth' scenario. Another one is particle concentration models, in which small pebbles are concentrated locally and then collapse gravitationally to form planetesimals. Both types of models make certain predictions for the size spectrum and internal structure of newly born planetesimals. We use these predictions as input to simulate collisional evolution of debris discs left after the gas dispersal. The debris disc emission as a function of a system's age computed in these simulations is compared with several Spitzer and Herschel debris disc surveys around A-type stars. We confirm that the observed brightness evolution for the majority of discs can be reproduced by classical models. Further, we find that it is equally consistent with the size distribution of planetesimals predicted by particle concentration models - provided the objects are loosely bound `pebble piles' as these models also predict. Regardless of the assumed planetesimal formation mechanism, explaining the brightest debris discs in the samples uncovers a `disc mass problem'. To reproduce such discs by collisional simulations, a total mass of planetesimals of up to ˜1000 Earth masses is required, which exceeds the total mass of solids available in the protoplanetary progenitors of debris discs. This may indicate that stirring was delayed in some of the bright discs, that giant impacts occurred recently in some of them, that some systems may be younger than previously thought or that non-collisional processes contribute significantly to the dust production.

  6. Resolving the planetesimal belt of HR 8799 with ALMA

    Science.gov (United States)

    Booth, Mark; Jordán, Andrés; Casassus, Simon; Hales, Antonio S.; Dent, William R. F.; Faramaz, Virginie; Matrà, Luca; Barkats, Denis; Brahm, Rafael; Cuadra, Jorge

    2016-07-01

    The star HR 8799 hosts one of the largest known debris discs and at least four giant planets. Previous observations have found evidence for a warm belt within the orbits of the planets, a cold planetesimal belt beyond their orbits and a halo of small grains. With the infrared data, it is hard to distinguish the planetesimal belt emission from that of the grains in the halo. With this in mind, the system has been observed with ALMA in band 6 (1.34 mm) using a compact array format. These observations allow the inner edge of the planetesimal belt to be resolved for the first time. A radial distribution of dust grains is fitted to the data using an MCMC method. The disc is best fitted by a broad ring between 145^{+12}_{-12} au and 429^{+37}_{-32} au at an inclination of 40^{+5}_{-6}° and a position angle of 51^{+8}_{-8}°. A disc edge at ˜145 au is too far out to be explained simply by interactions with planet b, requiring either a more complicated dynamical history or an extra planet beyond the orbit of planet b.

  7. CAPTURE OF PLANETESIMALS BY GAS DRAG FROM CIRCUMPLANETARY DISKS

    International Nuclear Information System (INIS)

    Fujita, Tetsuya; Ohtsuki, Keiji; Suetsugu, Ryo; Tanigawa, Takayuki

    2013-01-01

    Growing giant planets have circumplanetary disks around them in the late stage of their formation if their mass is sufficiently large. We examine capture of relatively large planetesimals that are decoupled from the gas inflow, due to gas drag from a circumplanetary disk of a growing giant planet. Assuming that the structure of the circumplanetary disk is axisymmetric, and solving the three-body problem including gas drag, we perform analytic and numerical calculations for capture of planetesimals. When planetesimal random velocity is small, planetesimals approaching in the retrograde direction are more easily captured, owing to their larger velocity relative to the gas. Planetesimals with large orbital inclinations interact with the disk for a short period of time and show lower capture rates. The effect of ablation on capture rates seems insignificant, although mass loss due to ablation would be significant in the case of high random velocity. We also examine the effect of non-uniform radial distribution of planetesimals in the protoplanetary disk due to gap opening by the planet. When the random velocity of planetesimals is small, the planetesimal capture rate decreases rapidly as the half width of the gap in the planetesimal disk increases from two planetary Hill radii to three planetary Hill radii; planetesimals with low random velocities cannot approach the planet in the case of a sufficiently wide gap. Our results show that the radial distribution and random velocity of planetesimals in the protoplanetary disk are essentially important for the understanding of capture of planetesimals by circumplanetary disks

  8. PLANET-PLANET SCATTERING IN PLANETESIMAL DISKS

    International Nuclear Information System (INIS)

    Raymond, Sean N.; Armitage, Philip J.; Gorelick, Noel

    2009-01-01

    We study the final architecture of planetary systems that evolve under the combined effects of planet-planet and planetesimal scattering. Using N-body simulations we investigate the dynamics of marginally unstable systems of gas and ice giants both in isolation and when the planets form interior to a planetesimal belt. The unstable isolated systems evolve under planet-planet scattering to yield an eccentricity distribution that matches that observed for extrasolar planets. When planetesimals are included the outcome depends upon the total mass of the planets. For M tot ∼> 1 M J the final eccentricity distribution remains broad, whereas for M tot ∼ J a combination of divergent orbital evolution and recircularization of scattered planets results in a preponderance of nearly circular final orbits. We also study the fate of marginally stable multiple planet systems in the presence of planetesimal disks, and find that for high planet masses the majority of such systems evolve into resonance. A significant fraction leads to resonant chains that are planetary analogs of Jupiter's Galilean satellites. We predict that a transition from eccentric to near-circular orbits will be observed once extrasolar planet surveys detect sub-Jovian mass planets at orbital radii of a ≅ 5-10 AU.

  9. Planetesimals Born Big by Clustering Instability?

    Science.gov (United States)

    Cuzzi, Jeffrey N.; Hartlep, Thomas; Simon, Justin I.; Estrada, Paul R.

    2017-01-01

    Roughly 100km diameter primitive bodies (today's asteroids and TNOs; [1]) are thought to be the end product of so-called "primary accretion". They dominated the initial mass function of planetesimals, and precipitated the onset of a subsequent stage, characterized by runaway gravitational effects, which proceeded onwards to planetary mass objects, some of which accreted massive gas envelopes. Asteroids are the parents of primitive meteorites; meteorite data suggest that asteroids initially formed directly from freelyfloating nebula particles in the mm-size range. Unfortunately, the process by which these primary 100km diameter planetesimals formed remains problematic. We review the most diagnostic primitive parent body observations, highlight critical aspects of the nebula context, and describe the issues facing various primary accretion models. We suggest a path forward that combines current scenarios of "turbulent concentration" (TC) and "streaming instabilities" (SI) into a triggered formation process we call clustering instability (CI). Under expected conditions of nebula turbulence, the success of these processes at forming terrestrial region (mostly silicate) planetesimals requires growth by sticking into aggregates in the several cm size range, at least, which is orders of magnitude more massive than allowed by current growth-by-sticking models using current experimental sticking parameters [2-4]. The situation is not as dire in the ice-rich outer solar system; however, growth outside of the snowline has important effects on growth inside of it [4] and at least one aspect of outer solar system planetesimals (high binary fraction) supports some kind of clustering instability

  10. Dust Evolution in Protoplanetary Discs and the Formation of Planetesimals. What Have We Learned from Laboratory Experiments?

    Science.gov (United States)

    Blum, Jürgen

    2018-03-01

    After 25 years of laboratory research on protoplanetary dust agglomeration, a consistent picture of the various processes that involve colliding dust aggregates has emerged. Besides sticking, bouncing and fragmentation, other effects, like, e.g., erosion or mass transfer, have now been extensively studied. Coagulation simulations consistently show that μm-sized dust grains can grow to mm- to cm-sized aggregates before they encounter the bouncing barrier, whereas sub-μm-sized water-ice particles can directly grow to planetesimal sizes. For siliceous materials, other processes have to be responsible for turning the dust aggregates into planetesimals. In this article, these processes are discussed, the physical properties of the emerging dusty or icy planetesimals are presented and compared to empirical evidence from within and without the Solar System. In conclusion, the formation of planetesimals by a gravitational collapse of dust "pebbles" seems the most likely.

  11. The origin of the planetesimal theory.

    Science.gov (United States)

    Brush, S G

    1977-04-01

    T. C. Chamberlin suggested in 1897, on the basis of geological and climatological arguments, that the planets were formed by accretion of cold solid partices. With F. R. Moulton he developed convincing arguments against the Laplace nebular hypothesis and published a comprehensive 'planetesimal theory' of the origin of the solar system in 1905. The Chamberlin-Moulton theory has current as well as historical interest.

  12. Impact splash chondrule formation during planetesimal recycling

    OpenAIRE

    Lichtenberg, Tim; Golabek, Gregor J.; Dullemond, Cornelis P.; Schönbächler, Maria; Gerya, Taras V.; Meyer, Michael R.

    2017-01-01

    Chondrules are the dominant bulk silicate constituent of chondritic meteorites and originate from highly energetic, local processes during the first million years after the birth of the Sun. So far, an astrophysically consistent chondrule formation scenario, explaining major chemical, isotopic and textural features, remains elusive. Here, we examine the prospect of forming chondrules from planetesimal collisions. We show that intensely melted bodies with interior magma oceans became rapidly c...

  13. Elemental compositions of two extrasolar rocky planetesimals

    Energy Technology Data Exchange (ETDEWEB)

    Xu, S.; Jura, M.; Klein, B.; Zuckerman, B. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1562 (United States); Koester, D., E-mail: sxu@astro.ucla.edu, E-mail: jura@astro.ucla.edu, E-mail: kleinb@astro.ucla.edu, E-mail: ben@astro.ucla.edu, E-mail: koester@astrophysik.uni-kiel.de [Institut fur Theoretische Physik und Astrophysik, University of Kiel, D-24098 Kiel (Germany)

    2014-03-10

    We report Keck/HIRES and Hubble Space Telescope/COS spectroscopic studies of extrasolar rocky planetesimals accreted onto two hydrogen atmosphere white dwarfs, G29-38 and GD 133. In G29-38, eight elements are detected, including C, O, Mg, Si, Ca, Ti, Cr, and Fe while in GD 133, O, Si, Ca, and marginally Mg are seen. These two extrasolar planetesimals show a pattern of refractory enhancement and volatile depletion. For G29-38, the observed composition can be best interpreted as a blend of a chondritic object with some refractory-rich material, a result from post-nebular processing. Water is very depleted in the parent body accreted onto G29-38, based on the derived oxygen abundance. The inferred total mass accretion rate in GD 133 is the lowest of all known dusty white dwarfs, possibly due to non-steady state accretion. We continue to find that a variety of extrasolar planetesimals all resemble to zeroth order the elemental composition of bulk Earth.

  14. Formation of the terrestrial planets in the solar system around 1 au via radial concentration of planetesimals

    Science.gov (United States)

    Ogihara, Masahiro; Kokubo, Eiichiro; Suzuki, Takeru K.; Morbidelli, Alessandro

    2018-05-01

    Context. No planets exist inside the orbit of Mercury and the terrestrial planets of the solar system exhibit a localized configuration. According to thermal structure calculation of protoplanetary disks, a silicate condensation line ( 1300 K) is located around 0.1 au from the Sun except for the early phase of disk evolution, and planetesimals could have formed inside the orbit of Mercury. A recent study of disk evolution that includes magnetically driven disk winds showed that the gas disk obtains a positive surface density slope inside 1 au from the central star. In a region with positive midplane pressure gradient, planetesimals undergo outward radial drift. Aims: We investigate the radial drift of planetesimals and type I migration of planetary embryos in a disk that viscously evolves with magnetically driven disk winds. We show a case in which no planets remain in the close-in region. Methods: Radial drifts of planetesimals are simulated using a recent disk evolution model that includes effects of disk winds. The late stage of planet formation is also examined by performing N-body simulations of planetary embryos. Results: We demonstrate that in the middle stage of disk evolution, planetesimals can undergo convergent radial drift in a magnetorotational instability (MRI)-inactive disk, in which the pressure maximum is created, and accumulate in a narrow ring-like region with an inner edge at 0.7 au from the Sun. We also show that planetary embryos that may grow from the narrow planetesimal ring do not exhibit significant type I migration in the late stage of disk evolution. Conclusions: The origin of the localized configuration of the terrestrial planets of the solar system, in particular the deficit of close-in planets, can be explained by the convergent radial drift of planetesimals in disks with a positive pressure gradient in the close-in region.

  15. INITIAL PLANETESIMAL SIZES AND THE SIZE DISTRIBUTION OF SMALL KUIPER BELT OBJECTS

    International Nuclear Information System (INIS)

    Schlichting, Hilke E.; Fuentes, Cesar I.; Trilling, David E.

    2013-01-01

    The Kuiper Belt is a remnant from the early solar system and its size distribution contains many important constraints that can be used to test models of planet formation and collisional evolution. We show, by comparing observations with theoretical models, that the observed Kuiper Belt size distribution is well matched by coagulation models, which start with an initial planetesimal population with radii of about 1 km, and subsequent collisional evolution. We find that the observed size distribution above R ∼ 30 km is primordial, i.e., it has not been modified by collisional evolution over the age of the solar system, and that the size distribution below R ∼ 30 km has been modified by collisions and that its slope is well matched by collisional evolution models that use published strength laws. We investigate in detail the resulting size distribution of bodies ranging from 0.01 km to 30 km and find that its slope changes several times as a function of radius before approaching the expected value for an equilibrium collisional cascade of material strength dominated bodies for R ∼< 0.1 km. Compared to a single power-law size distribution that would span the whole range from 0.01 km to 30 km, we find in general a strong deficit of bodies around R ∼ 10 km and a strong excess of bodies around 2 km in radius. This deficit and excess of bodies are caused by the planetesimal size distribution left over from the runaway growth phase, which left most of the initial mass in small planetesimals while only a small fraction of the total mass is converted into large protoplanets. This excess mass in small planetesimals leaves a permanent signature in the size distribution of small bodies that is not erased after 4.5 Gyr of collisional evolution. Observations of the small Kuiper Belt Object (KBO) size distribution can therefore test if large KBOs grew as a result of runaway growth and constrained the initial planetesimal sizes. We find that results from recent KBO

  16. Sublimation of icy planetesimals and the delivery of water to the habitable zone around solar type stars

    Science.gov (United States)

    Brunini, Adrián; López, María Cristina

    2018-06-01

    We present a semi analytic model to evaluate the delivery of water to the habitable zone around a solar type star carried by icy planetesimals born beyond the snow line. The model includes sublimation of ice, gas drag and scattering by an outer giant planet located near the snow line. The sublimation model is general and could be applicable to planetary synthesis models or N-Body simulations of the formation of planetary systems. We perform a short series of simulations to asses the potential relevance of sublimation of volatiles in the process of delivery of water to the inner regions of a planetary system during early stages of its formation. We could anticipate that erosion by sublimation would prevent the arrival of much water to the habitable zone of protoplanetary disks in the form of icy planetesimals. Close encounters with a massive planet orbiting near the outer edge of the snow line could make possible for planetesimals to reach the habitable zone somewhat less eroded. However, only large planetesimals could provide appreciable amounts of water. Massive disks and sharp gas surface density profiles favor icy planetesimals to reach inner regions of a protoplanetary disk.

  17. Fluffy dust forms icy planetesimals by static compression

    Science.gov (United States)

    Kataoka, Akimasa; Tanaka, Hidekazu; Okuzumi, Satoshi; Wada, Koji

    2013-09-01

    Context. Several barriers have been proposed in planetesimal formation theory: bouncing, fragmentation, and radial drift problems. Understanding the structure evolution of dust aggregates is a key in planetesimal formation. Dust grains become fluffy by coagulation in protoplanetary disks. However, once they are fluffy, they are not sufficiently compressed by collisional compression to form compact planetesimals. Aims: We aim to reveal the pathway of dust structure evolution from dust grains to compact planetesimals. Methods: Using the compressive strength formula, we analytically investigate how fluffy dust aggregates are compressed by static compression due to ram pressure of the disk gas and self-gravity of the aggregates in protoplanetary disks. Results: We reveal the pathway of the porosity evolution from dust grains via fluffy aggregates to form planetesimals, circumventing the barriers in planetesimal formation. The aggregates are compressed by the disk gas to a density of 10-3 g/cm3 in coagulation, which is more compact than is the case with collisional compression. Then, they are compressed more by self-gravity to 10-1 g/cm3 when the radius is 10 km. Although the gas compression decelerates the growth, the aggregates grow rapidly enough to avoid the radial drift barrier when the orbital radius is ≲6 AU in a typical disk. Conclusions: We propose a fluffy dust growth scenario from grains to planetesimals. It enables icy planetesimal formation in a wide range beyond the snowline in protoplanetary disks. This result proposes a concrete initial condition of planetesimals for the later stages of the planet formation.

  18. Formation of planetesimals in the Solar Nebula

    Science.gov (United States)

    Hueso, R.; Guillot, T.

    2001-11-01

    We study the evolution of protoplanetary disks with gas and embedded particles using a classical alpha-disk model. Solid matter entrained in the gas is incorporated following the formalism of Stepinski and Valageas (A&A, 1996, 1997). Dust grains coagulate into larger particles until they eventually decouple from the gas. The coagulation process is modulated by the evaporation and condensation of dust in the disk. We simultaneously consider grains of ices and rock, which allows us to study the amount of different solid material available to form the different planets. In particular, we present consequences for the development of planetesimals in the Uranus and Neptune region. This is interesting in the light of interior models of these planets, which naturally tend to predict a low rock to ice ratio. We will also discuss the consequences of these results on the standard core-accretion formation scenario. Acknowledgements: This work has been supported by Programme National du Planetologie. R. Hueso acknowledges a post-doctoral fellowship from Gobierno Vasco.

  19. Planetesimal formation by sweep-up coagulation

    Science.gov (United States)

    Windmark, Fredrik; Birnstiel, Til; Ormel, Chris W.; Dullemond, Cornelis P.

    2013-07-01

    The formation of planetesimals is often accredited to collisional sticking of dust grains in the protoplanetary disk. The exact process is however unknown, as collisions between larger aggregates tend to lead to fragmentation or bouncing rather than sticking. These growth barriers tend to halt the dust growth already at millimeters or centimeters in size, which is far below the kilometer-sizes that are needed for gravity to aid in the accretion. To study how far dust coagulation can proceed, we have developed a new collision model based on the latest laboratory experiments, and have used it together with a dust-size evolution code capable of resolving all grain interactions in the protoplanetary disk. We find that for the general dust population, bouncing and fragmenting collisions prevent the growth above millimeter-sizes. However, a small number of lucky particles can grow larger than the rest by only interacting at low, sticky velocities. As they grow, they become increasingly resilient to fragmentation caused by the small grains. In this way, two populations are formed: One which remains small due to the collisional barriers, and one that continues to grow by sweeping up the smaller grains around them.

  20. Silicon isotopes in angrites and volatile loss in planetesimals

    Science.gov (United States)

    Moynier, Frédéric; Savage, Paul S.; Badro, James; Barrat, Jean-Alix

    2014-01-01

    Inner solar system bodies, including the Earth, Moon, and asteroids, are depleted in volatile elements relative to chondrites. Hypotheses for this volatile element depletion include incomplete condensation from the solar nebula and volatile loss during energetic impacts. These processes are expected to each produce characteristic stable isotope signatures. However, processes of planetary differentiation may also modify the isotopic composition of geochemical reservoirs. Angrites are rare meteorites that crystallized only a few million years after calcium–aluminum-rich inclusions and exhibit extreme depletions in volatile elements relative to chondrites, making them ideal samples with which to study volatile element depletion in the early solar system. Here we present high-precision Si isotope data that show angrites are enriched in the heavy isotopes of Si relative to chondritic meteorites by 50–100 ppm/amu. Silicon is sufficiently volatile such that it may be isotopically fractionated during incomplete condensation or evaporative mass loss, but theoretical calculations and experimental results also predict isotope fractionation under specific conditions of metal–silicate differentiation. We show that the Si isotope composition of angrites cannot be explained by any plausible core formation scenario, but rather reflects isotope fractionation during impact-induced evaporation. Our results indicate planetesimals initially formed from volatile-rich material and were subsequently depleted in volatile elements during accretion. PMID:25404309

  1. Accretion of Planetesimals and the Formation of Rocky Planets

    Science.gov (United States)

    Chambers, John E.; O'Brien, David P.; Davis, Andrew M.

    2010-02-01

    Here we describe the formation of rocky planets and asteroids in the context of the planetesimal hypothesis. Small dust grains in protoplanetary disks readily stick together forming mm-to-cm-sized aggregates, many of which experience brief heating episodes causing melting. Growth to km-sized planetesimals might proceed via continued pairwise sticking, turbulent concentration, or gravitational instability of a thin particle layer. Gravitational interactions between planetesimals lead to rapid runaway and oligarchic growth forming lunar-to-Mars-sized protoplanets in 10^5 to 10^6 years. Giant impacts between protoplanets form Earth-mass planets in 10^7 to 10^8 years, and occasionally lead to the formation of large satellites. Protoplanets may migrate far from their formation locations due to tidal interactions with the surrounding disk. Radioactive decay and impact heating cause melting and differentiation of planetesimals and protoplanets, forming iron-rich cores and silicate mantles, and leading to some loss of volatiles. Dynamical perturbations from giant planets eject most planetesimals and protoplanets from regions near orbital resonances, leading to asteroid-belt formation. Some of this scattered material will collide with growing terrestrial planets, altering their composition as a result. Numerical simulations and radioisotope dating indicate that the terrestrial planets of the Solar System were essentially fully formed in 100-200 million years.

  2. The Evidence Against Learnability of Early Motor Skills Reconsidered.

    Science.gov (United States)

    Razel, Micha

    This paper attempts to refute the assumption that early motor development is determined genetically and is not influenced by environmental factors. The paper re-examines three studies which are consistently cited as providing evidence for a maturational theory of motor development: the "early training study" by Gesell and Thompson, the "swaddling…

  3. Implications of the interstellar object 1I/'Oumuamua for planetary dynamics and planetesimal formation

    Science.gov (United States)

    Raymond, Sean N.; Armitage, Philip J.; Veras, Dimitri; Quintana, Elisa V.; Barclay, Thomas

    2018-05-01

    'Oumuamua, the first bona fide interstellar planetesimal, was discovered passing through our Solar system on a hyperbolic orbit. This object was likely dynamically ejected from an extrasolar planetary system after a series of close encounters with gas giant planets. To account for 'Oumuamua's detection, simple arguments suggest that ˜1 M⊕ of planetesimals are ejected per solar mass of Galactic stars. However, that value assumes mono-sized planetesimals. If the planetesimal mass distribution is instead top-heavy, the inferred mass in interstellar planetesimals increases to an implausibly high value. The tension between theoretical expectations for the planetesimal mass function and the observation of 'Oumuamua can be relieved if a small fraction ({˜ } 0.1-1 {per cent}) of planetesimals are tidally disrupted on the pathway to ejection into 'Oumuamua-sized fragments. Using a large suite of simulations of giant planet dynamics including planetesimals, we confirm that 0.1-1 per cent of planetesimals pass within the tidal disruption radius of a gas giant on their pathway to ejection. 'Oumuamua may thus represent a surviving fragment of a disrupted planetesimal. Finally, we argue that an asteroidal composition is dynamically disfavoured for 'Oumuamua, as asteroidal planetesimals are both less abundant and ejected at a lower efficiency than cometary planetesimals.

  4. Planetesimal Sizes and Mars Formation in the Magnetized Solar Nebula

    Science.gov (United States)

    Hasegawa, Yasuhiro; Morishima, Ryuji

    2017-10-01

    The Hf-W chronology inferred from Martian meteorites suggests that Mars should be a stranded planetary embryo formed within a very short (about 2 Myr) accretion timescale. Previous studies show that such rapid growth can be realized when small (nebular evolution. Under this circumstance, impact velocity of planetesimals can be very high due to nebular density fluctuations caused by turbulence, and hence collisions between small planetesimals can become destructive, rather than mergers. Here, we investigate how Mars formed in the magnetized solar nebula, focusing on MHD turbulence. We demonstrate what mass of planetesimals can contribute to Mars formation and what value of the nebular mass is needed to satisfy the rapid accretion timescale. We therefore derive a more realistic condition of the solar nebula under which Mars formation took place. While this study is based on the standard picture of runaway and oligarchic growth, we also discuss other formation mechanisms in order to compare how our results would be consistent with the properties of the solar system. These mechanisms are a hypothesis that Mars formed from a narrow ring of planetesimals, and the pebble accretion scenario.

  5. MIGRATION RATES OF PLANETS DUE TO SCATTERING OF PLANETESIMALS

    International Nuclear Information System (INIS)

    Ormel, C. W.; Ida, S.; Tanaka, H.

    2012-01-01

    Planets migrate due to the recoil they experience from scattering solid (planetesimal) bodies. To first order, the torques exerted by the interior and exterior disks will cancel, analogous to the cancellation of the torques from the gravitational interaction with the gas (Type-I migration). Assuming the dispersion-dominated regime and power laws characterized by indices α and β for the surface density and eccentricity profiles, we calculate the net torque on the planet. We consider both distant encounters and close (orbit-crossing) encounters. We find that the close and distant encounter torques have opposite signs with respect to α and β; and that the torque is especially sensitive to the eccentricity gradient β. Compared to Type-I migration due to excitation of density waves, the planetesimal-driven migration rate is generally lower due to the lower surface density of solids in gas-rich disk, although this may be partially or fully offset when their eccentricity and inclinaton are small. Allowing for the feedback of the planet on the planetesimal disk through viscous stirring, we find that under certain conditions a self-regulated migration scenario emerges, in which the planet migrates at a steady pace that approaches the rate corresponding to the one-sided torque. If the ratio of the local disk mass in planetesimals to planet mass is low, however, migration will stall. We quantify the boundaries separating the three accretion regimes.

  6. The planetesimal-driven migration of planets: Observational consequences

    International Nuclear Information System (INIS)

    Panichi, F.

    2014-01-01

    The role of planetary migration in a non–self-gravity planetesimals disk is analyzed in this paper. I calculate the migration rate exerted on a planet due to the gravitational interaction with a planetesimals disk both numerically and analytically. I use two different configurations for the disk-planet interaction: corotating (with an inclination of 0◦ with respect to the plane of motion of the disk) and counter-rotating (with an inclination of 180◦) planet. I perform 2D numerical simulations of disks with 104 planetesimals with or without a Rayleigh distribution in eccentricity. I show that counter- and co-rotating planets have different migration rates: retrograde planets migrate faster than the prograde ones. The migration rate depends on the ratio between the planet to planetesimal mass and on the initial mean eccentricity of planetesimals. I compare numerical simulations with analytical theories of dynamical friction and linear theory of density waves. In both cases each theory can explain only parts of the simulation results. A more general and powerful analytical theory of planet migration must be realized. Finally I simulate the observation of co- and counter-rotating massless disks of planetesimals with the interferometer ALMA. With the high resolution of ALMA it is possible to characterize the gap created by the resonances overlap. I show that in the two cases different resonance conditions create gaps with different extensions which can be observed with ALMA for a distance of 100 parsec and a disk size of 100 A.U., and for disks of 20 A.U. and a distance of 50 parsec. With this simple method it is possible to calculate the planet’s mass in both cases studying the indirect presence of the planet. The case of massive disks are also investigated. In this case planet migration creates a large modification of the planetesimals density profile that can be studied observing the brightness surface profile of the disk. Conversely to other detection

  7. Experimental Evidence on the Effects of Early Meetings and Activation

    DEFF Research Database (Denmark)

    Pedersen, Jonas Maibom; Rosholm, Michael; Svarer, Michael

    and case workers increase employment rates over the next two years by 10%. For men, we find evidence of a threat effect of having to participate in early activation programmes. In general, we find large differences between men and women, especially in the dynamics of the effects. A cost-benefit analysis...

  8. TURBULENT CLUSTERING OF PROTOPLANETARY DUST AND PLANETESIMAL FORMATION

    International Nuclear Information System (INIS)

    Pan Liubin; Padoan, Paolo; Scalo, John; Kritsuk, Alexei G.; Norman, Michael L.

    2011-01-01

    We study the clustering of inertial particles in turbulent flows and discuss its applications to dust particles in protoplanetary disks. Using numerical simulations, we compute the radial distribution function (RDF), which measures the probability of finding particle pairs at given distances, and the probability density function of the particle concentration. The clustering statistics depend on the Stokes number, St, defined as the ratio of the particle friction timescale, τ p , to the Kolmogorov timescale in the flow. In agreement with previous studies, we find that, in the dissipation range, the clustering intensity strongly peaks at St ≅ 1, and the RDF for St ∼ 1 shows a fast power-law increase toward small scales, suggesting that turbulent clustering may considerably enhance the particle collision rate. Clustering at inertial-range scales is of particular interest to the problem of planetesimal formation. At these large scales, the strongest clustering is from particles with τ p in the inertial range. Clustering of these particles occurs primarily around a scale where the eddy turnover time is ∼τ p . We find that particles of different sizes tend to cluster at different locations, leading to flat RDFs between different particles at small scales. In the presence of multiple particle sizes, the overall clustering strength decreases as the particle size distribution broadens. We discuss particle clustering in two recent models for planetesimal formation. We argue that, in the model based on turbulent clustering of chondrule-size particles, the probability of finding strong clusters that can seed planetesimals may have been significantly overestimated. We discuss various clustering mechanisms in simulations of planetesimal formation by gravitational collapse of dense clumps of meter-size particles, in particular the contribution from turbulent clustering due to the limited numerical resolution.

  9. Evidence for a genetic etiology of early-onset delinquency.

    Science.gov (United States)

    Taylor, J; Iacono, W G; McGue, M

    2000-11-01

    Age at onset of antisocial behavior discriminates persistent and transitory offenders. The authors proposed that early-onset delinquency has an underlying genetic influence that manifests in problems related to inhibition, whereas late-onset delinquency is more environmentally mediated. To test these notions, they selected 36 early starters, 86 late starters, and 25 nondelinquent controls from a large sample of 11-year-old twins and compared them on several measures related to inhibition and a peer group measure. As expected, early starters had more psychological, behavioral, and emotional problems related to inhibition than late starters and controls. A longitudinal analysis indicated an increase an antisocial behavior among peers of late starters shortly before their delinquency onset. Family history data and a twin analysis provided evidence of greater genetic influence on early-onset than late-onset delinquency.

  10. Early management of sepsis with emphasis on early goal directed therapy: AME evidence series 002

    OpenAIRE

    Zhang, Zhongheng; Hong, Yucai; Smischney, Nathan J.; Kuo, Han-Pin; Tsirigotis, Panagiotis; Rello, Jordi; Kuan, Win Sen; Jung, Christian; Robba, Chiara; Taccone, Fabio Silvio; Leone, Marc; Spapen, Herbert; Grimaldi, David; Van Poucke, Sven; Simpson, Steven Q.

    2017-01-01

    Severe sepsis and septic shock are major causes of morbidity and mortality in patients entering the emergency department (ED) or intensive care unit (ICU). Despite substantial efforts to improve patient outcome, treatment of sepsis remains challenging to clinicians. In this context, early goal directed therapy (EGDT) represents an important concept emphasizing both early recognition of sepsis and prompt initiation of a structured treatment algorithm. As part of the AME evidence series on seps...

  11. PLANET FORMATION IN STELLAR BINARIES. I. PLANETESIMAL DYNAMICS IN MASSIVE PROTOPLANETARY DISKS

    International Nuclear Information System (INIS)

    Rafikov, Roman R.; Silsbee, Kedron

    2015-01-01

    About 20% of exoplanets discovered by radial velocity surveys reside in stellar binaries. To clarify their origin one has to understand the dynamics of planetesimals in protoplanetary disks within binaries. The standard description, accounting for only gas drag and gravity of the companion star, has been challenged recently, as the gravity of the protoplanetary disk was shown to play a crucial role in planetesimal dynamics. An added complication is the tendency of protoplanetary disks in binaries to become eccentric, giving rise to additional excitation of planetesimal eccentricity. Here, for the first time, we analytically explore the secular dynamics of planetesimals in binaries such as α Cen and γ Cep under the combined action of (1) gravity of the eccentric protoplanetary disk, (2) perturbations due to the (coplanar) eccentric companion, and (3) gas drag. We derive explicit solutions for the behavior of planetesimal eccentricity e p in non-precessing disks (and in precessing disks in certain limits). We obtain the analytical form of the distribution of the relative velocities of planetesimals, which is a key input for understanding their collisional evolution. Disk gravity strongly influences relative velocities and tends to push the sizes of planetesimals colliding with comparable objects at the highest speed to small values, ∼1 km. We also find that planetesimals in eccentric protoplanetary disks apsidally aligned with the binary orbit collide at lower relative velocities than in misaligned disks. Our results highlight the decisive role that disk gravity plays in planetesimal dynamics in binaries

  12. An Empirical Planetesimal Belt Radius–Stellar Luminosity Relation

    Science.gov (United States)

    Matrà, L.; Marino, S.; Kennedy, G. M.; Wyatt, M. C.; Öberg, K. I.; Wilner, D. J.

    2018-05-01

    Resolved observations of millimeter-sized dust, tracing larger planetesimals, have pinpointed the location of 26 Edgeworth–Kuiper Belt analogs. We report that a belt’s distance R to its host star correlates with the star’s luminosity L ⋆, following R\\propto {L}\\star 0.19 with a low intrinsic scatter of ∼17%. Remarkably, our Edgeworth–Kuiper Belt in the solar system and the two CO snow lines imaged in protoplanetary disks lie close to this R–L ⋆ relation, suggestive of an intrinsic relationship between protoplanetary disk structures and belt locations. To test the effect of bias on the relation, we use a Monte Carlo approach and simulate uncorrelated model populations of belts. We find that observational bias could produce the slope and intercept of the R–L ⋆ relation but is unable to reproduce its low scatter. We then repeat the simulation taking into account the collisional evolution of belts, following the steady-state model that fits the belt population as observed through infrared excesses. This significantly improves the fit by lowering the scatter of the simulated R–L ⋆ relation; however, this scatter remains only marginally consistent with the one observed. The inability of observational bias and collisional evolution alone to reproduce the tight relationship between belt radius and stellar luminosity could indicate that planetesimal belts form at preferential locations within protoplanetary disks. The similar trend for CO snow line locations would then indicate that the formation of planetesimals or planets in the outer regions of planetary systems is linked to the volatility of their building blocks, as postulated by planet formation models.

  13. Investigating Planetesimal Evolution by Experiments with Fe-Ni Metallic Melts: Light Element Composition Effects on Trace Element Partitioning Behavior

    Science.gov (United States)

    Chabot, N. L.

    2017-12-01

    As planetesimals were heated up in the early Solar System, the formation of Fe-Ni metallic melts was a common occurrence. During planetesimal differentiation, the denser Fe-Ni metallic melts separated from the less dense silicate components, though some meteorites suggest that their parent bodies only experienced partial differentiation. If the Fe-Ni metallic melts did form a central metallic core, the core eventually crystallized to a solid, some of which we sample as iron meteorites. In all of these planetesimal evolution processes, the composition of the Fe-Ni metallic melt influenced the process and the resulting trace element chemical signatures. In particular, the metallic melt's "light element" composition, those elements present in the metallic melt in a significant concentration but with lower atomic masses than Fe, can strongly affect trace element partitioning. Experimental studies have provided critical data to determine the effects of light elements in Fe-Ni metallic melts on trace element partitioning behavior. Here I focus on combining numerous experimental results to identify trace elements that provide unique insight into constraining the light element composition of early Solar System Fe-Ni metallic melts. Experimental studies have been conducted at 1 atm in a variety of Fe-Ni systems to investigate the effects of light elements on trace element partitioning behavior. A frequent experimental examination of the effects of light elements in metallic systems involves producing run products with coexisting solid metal and liquid metal phases. Such solid-metal-liquid-metal experiments have been conducted in the Fe-Ni binary system as well as Fe-Ni systems with S, P, and C. Experiments with O-bearing or Si-bearing Fe-Ni metallic melts do not lend themselves to experiments with coexisting solid metal and liquid metal phases, due to the phase diagrams of these elements, but experiments with two immiscible Fe-Ni metallic melts have provided insight into

  14. Evidence for early hunters beneath the Great Lakes.

    Science.gov (United States)

    O'Shea, John M; Meadows, Guy A

    2009-06-23

    Scholars have hypothesized that the poorly understood and rarely encountered archaeological sites from the terminal Paleoindian and Archaic periods associated with the Lake Stanley low water stage (10,000-7,500 BP) are lost beneath the modern Great Lakes. Acoustic and video survey on the Alpena-Amberley ridge, a feature that would have been a dry land corridor crossing the Lake Huron basin during this time period, reveals the presence of a series of stone features that match, in form and location, structures used for caribou hunting in both prehistoric and ethnographic times. These results present evidence for early hunters on the Alpena-Amberley corridor, and raise the possibility that intact settlements and ancient landscapes are preserved beneath Lake Huron.

  15. PLANET FORMATION IN HIGHLY INCLINED BINARY SYSTEMS. I. PLANETESIMALS JUMP INWARD AND PILE UP

    International Nuclear Information System (INIS)

    Xie Jiwei; Zhou Jilin; Payne, Matthew J.; Ge Jian; Thebault, Philippe

    2011-01-01

    Most detected planet-bearing binaries are in wide orbits, for which a high inclination, i B , between the binary orbital plane and the plane of the planetary disk around the primary is likely to be common. In this paper, we investigate the intermediate stages-from planetesimals to planetary embryos/cores-of planet formation in such highly inclined cases. Our focus is on the effects of gas drag on the planetesimals' orbital evolution, in particular on the evolution of the planetesimals' semimajor axis distribution and their mutual relative velocities. We first demonstrate that a non-evolving axisymmetric disk model is a good approximation for studying the effects of gas drag on a planetesimal in the highly inclined case (30 deg. B B . For both regimes, a robust outcome over a wide range of parameters is that planetesimals migrate/jump inward and pile up, leading to a severely truncated and dense planetesimal disk around the primary. In this compact and dense disk, collision rates are high but relative velocities are low, providing conditions that are favorable for planetesimal growth and potentially allow for the subsequent formation of planets.

  16. Migration of planetesimals during last stages of giant planet accumulation

    International Nuclear Information System (INIS)

    Ipatov, S.I.

    1989-01-01

    The migration and accumulation of bodies from the giant planet's feeding zones are investigated after the main part of mass of these planets had been formed. These investigations are based on the computer simulation results for the evolving spatial disks which initially consisted of a few almost formed planets and hundreds of identical bodies in Uranus and Neptune zone. It is shown that the total mass of bodies penetrated in the asteroid zone from the giant planet zones could be ten times as large as the Earth mass. The beyond-Neptune belt could form during accumulation of the giant planets. Evolution of the planet orbits under encounters of planets with planetesimals is investigated

  17. Microbiological evidence for Fe(III) reduction on early Earth

    Science.gov (United States)

    Vargas, Madeline; Kashefi, Kazem; Blunt-Harris, Elizabeth L.; Lovley, Derek R.

    1998-09-01

    It is generally considered that sulphur reduction was one of the earliest forms of microbial respiration, because the known microorganisms that are most closely related to the last common ancestor of modern life are primarily anaerobic, sulphur-reducing hyperthermophiles. However, geochemical evidence indicates that Fe(III) is more likely than sulphur to have been the first external electron acceptor of global significance in microbial metabolism. Here we show that Archaea and Bacteria that are most closely related to the last common ancestor can reduce Fe(III) to Fe(II) and conserve energy to support growth from this respiration. Surprisingly, even Thermotoga maritima, previously considered to have only a fermentative metabolism, could grow as a respiratory organism when Fe(III) was provided as an electron acceptor. These results provide microbiological evidence that Fe(III) reduction could have been an important process on early Earth and suggest that microorganisms might contribute to Fe(III) reduction in modern hot biospheres. Furthermore, our discovery that hyperthermophiles that had previously been thought to require sulphur for cultivation can instead be grown without the production of toxic and corrosive sulphide, should aid biochemical investigations of these poorly understood organisms.

  18. Synthesis of Amino Acid Precursors with Organic Solids in Planetesimals with Liquid Water

    Science.gov (United States)

    Kebukawa, Y.; Chan, Q. H. S.; Misawa, S.; Matsukuma, J.; Tachibana, S.; Kobayashi, K.; Zolensky, M. E.

    2017-07-01

    We demonstrated synthesis of a complex suite of amino acids simultaneously with IOM via hydrothermal experiments starting from formaldehyde, glycolaldehyde and ammonia, simulating the aqueous processing in the planetesimals.

  19. The Early Universe: Searching for Evidence of Cosmic Inflation

    Science.gov (United States)

    Chuss, David T.

    2012-01-01

    In the past two decades, our understanding of the evolution and fate of the universe has increased dramatically. This "Age of Precision Cosmology" has been ushered in by measurements that have both elucidated the details of the Big Bang cosmology and set the direction for future lines of inquiry. Our universe appears to consist of 5% baryonic matter; 23% of the universe's energy content is dark matter which is responsible for the observed structure in the universe; and 72% of the energy density is so-called "dark energy" that is currently accelerating the expansion of the universe. In addition, our universe has been measured to be geometrically flat to 1 %. These observations and related details of the Big Bang paradigm have hinted that the universe underwent an epoch of accelerated expansion known as "inflation" early in its history. In this talk, I will review the highlights of modern cosmology, focusing on the contributions made by measurements of the cosmic microwave background, the faint afterglow of the Big Bang. I will also describe new instruments designed to measure the polarization of the cosmic microwave background in order to search for evidence of cosmic inflation.

  20. From Dust Grains to Planetesimals: The Importance of the Streaming Instability in Protoplanetary Disks

    Science.gov (United States)

    Simon, Jacob B.; Armitage, Philip J.; Youdin, Andrew N.; Li, Rixin

    2016-01-01

    Planetesimals are the precursors to planets, and understanding their formation is an essential step towards developing a complete theory of planet formation. For small solid particles (e.g., dust grains) to coagulate into planetesimals, however, requires that these particles grow beyond centimeter sizes; with traditional coagulation physics, this is very difficult. The streaming instability, which is a clumping process akin to the pile-up of cars in a traffic jam, generates sufficiently high solid densities that the mutual gravity between the clumped particles eventually causes their collapse towards planetesimal mass and size scales. Exploring this transition from dust grains to planetesimals is still in its infancy but is extremely important if we want to understand the basics of planet formation. Here, I present a series of high resolution, first principles numerical simulations of protoplanetary disk gas and dust to study the clumping of particles via the streaming instability and the subsequent collapse towards planetesimals. These simulations have been employed to characterize the planetesimal population as a function of radius in protoplanetary disks. The results of these simulations will be crucial for planet formation models to correctly explain the formation and configuration of solar systems.

  1. WILL THE LARGE SYNOPTIC SURVEY TELESCOPE DETECT EXTRA-SOLAR PLANETESIMALS ENTERING THE SOLAR SYSTEM?

    International Nuclear Information System (INIS)

    Moro-Martin, Amaya; Turner, Edwin L.; Loeb, Abraham

    2009-01-01

    Planetesimal formation is a common by-product of the star formation process. Taking the dynamical history of the solar system as a guideline-in which the planetesimal belts were heavily depleted due to gravitational perturbation with the giant planets-and assuming similar processes have taken place in other planetary systems, one would expect the interstellar space to be filled with extra-solar planetesimals. However, not a single one of these objects has been detected so far entering the solar system, even though it would clearly be distinguishable from a solar system comet due to its highly hyperbolic orbit. The Large Synoptic Survey Telescope (LSST) will provide wide coverage maps of the sky to a very high sensitivity, ideal to detect moving objects like comets, both active and inactive. In anticipation of these observations, we estimate how many inactive 'interstellar comets' might be detected during the duration of the survey. The calculation takes into account estimates (from observations and models) of the number density of stars, the amount of solids available to form planetesimals, the frequency of planet and planetesimal formation, the efficiency of planetesimal ejection, and the possible size distribution of these small bodies.

  2. Evidence of Late Palaeocene-Early Eocene equatorial rain forest ...

    Indian Academy of Sciences (India)

    Prakash

    2009-11-02

    Nov 2, 2009 ... influx of CO2 during early Cenozoic times (Kent and Muttoni. 2008), besides ... Palaeocene – Eocene lignite and coal deposits of India. .... journey of the Indian subcontinent and massive outpouring ..... ice age (Plana 2004).

  3. Advertising to Early Trend Propagators: Evidence from Twitter

    OpenAIRE

    Lambrecht, A.; Tucker, C. M.; Wiertz, C.

    2018-01-01

    In the digital economy, influencing and controlling the spread of information is a key concern for firms. One way firms try to achieve this is to target firm communications to consumers who embrace and propagate the spread of new information on emerging and `trending' topics on social media. However, little is known about whether early trend propagators are indeed responsive to firm-sponsored messages. To explore whether early propagators of trending topics respond to advertising messages, we...

  4. Advertising to early trend propagators: evidence from Twitter

    OpenAIRE

    Lambrecht, A; Tucker, C; Wiertz, C

    2018-01-01

    In the digital economy, influencing and controlling the spread of information is a key concern for firms. One way firms try to achieve this is to target firm communications to consumers who embrace and propagate the spread of new information on emerging and `trending' topics on social media. However, little is known about whether early trend propagators are indeed responsive to firm-sponsored messages. To explore whether early propagators of trending topics respond to advertising messages, we...

  5. THE ROLE OF PEBBLE FRAGMENTATION IN PLANETESIMAL FORMATION. II. NUMERICAL SIMULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Karl Wahlberg; Johansen, Anders [Lund Observatory, Department of Astronomy and Theoretical Physics, Lund University, Box 43, SE-221 00 Lund (Sweden); Syed, Mohtashim Bukhari; Blum, Jürgen [Technische Universität Braunschweig, Institut für Geophysik und extraterrestrische Physik, Mendelssohnstraße 3, D-38106 Braunschweig (Germany)

    2017-01-20

    Some scenarios for planetesimal formation go through a phase of collapse of gravitationally bound clouds of millimeter- to centimeter-size pebbles. Such clouds can form, for example, through the streaming instability in protoplanetary disks. We model the collapse process with a statistical model to obtain the internal structure of planetesimals with solid radii between 10 and 1000 km. During the collapse, pebbles collide, and depending on their relative speeds, collisions have different outcomes. A mixture of particle sizes inside a planetesimal leads to better packing capabilities and higher densities. In this paper we apply results from new laboratory experiments of dust aggregate collisions (presented in a companion paper) to model collision outcomes. We find that the internal structure of a planetesimal is strongly dependent on both its mass and the applied fragmentation model. Low-mass planetesimals have no/few fragmenting pebble collisions in the collapse phase and end up as porous pebble piles. The number of fragmenting collisions increases with increasing cloud mass, resulting in wider particle size distributions and higher density. The collapse is nevertheless “cold” in the sense that collision speeds are damped by the high collision frequency. This ensures that a significant fraction of large pebbles survive the collapse in all but the most massive clouds. Our results are in broad agreement with the observed increase in density of Kuiper Belt objects with increasing size, as exemplified by the recent characterization of the highly porous comet 67P/Churyumov–Gerasimenko.

  6. GLOBAL HIGH-RESOLUTION N-BODY SIMULATION OF PLANET FORMATION. I. PLANETESIMAL-DRIVEN MIGRATION

    Energy Technology Data Exchange (ETDEWEB)

    Kominami, J. D. [Earth-Life Science Institute, Tokyo Institute of Technology, Meguro-Ku, Tokyo (Japan); Daisaka, H. [Hitotsubashi University, Kunitachi-shi, Tokyo (Japan); Makino, J. [RIKEN Advanced Institute for Computational Science, Chuo-ku, Kobe, Hyogo (Japan); Fujimoto, M., E-mail: kominami@mail.jmlab.jp, E-mail: daisaka@phys.science.hit-u.ac.jp, E-mail: makino@mail.jmlab.jp, E-mail: fujimoto.masaki@jaxa.jp [Japan Aerospace Exploration Agency, Sagamihara-shi, Kanagawa (Japan)

    2016-03-01

    We investigated whether outward planetesimal-driven migration (PDM) takes place or not in simulations when the self-gravity of planetesimals is included. We performed N-body simulations of planetesimal disks with a large width (0.7–4 au) that ranges over the ice line. The simulations consisted of two stages. The first-stage simulations were carried out to see the runaway growth phase using the planetesimals of initially the same mass. The runaway growth took place both at the inner edge of the disk and at the region just outside the ice line. This result was utilized for the initial setup of the second-stage simulations, in which the runaway bodies just outside the ice line were replaced by the protoplanets with about the isolation mass. In the second-stage simulations, the outward migration of the protoplanet was followed by the stopping of the migration due to the increase of the random velocity of the planetesimals. Owing to this increase of random velocities, one of the PDM criteria derived in Minton and Levison was broken. In the current simulations, the effect of the gas disk is not considered. It is likely that the gas disk plays an important role in PDM, and we plan to study its effect in future papers.

  7. Pediatric Bipolar Disorder: Evidence for Prodromal States and Early Markers

    Science.gov (United States)

    Luby, Joan L.; Navsaria, Neha

    2010-01-01

    Background: Childhood bipolar disorder remains a controversial but increasingly diagnosed disorder that is associated with significant impairment, chronic course and treatment resistance. Therefore, the search for prodromes or early markers of risk for later childhood bipolar disorder may be of great importance for prevention and/or early…

  8. Early mathematics development and later achievement: Further evidence

    Science.gov (United States)

    Aubrey, Carol; Godfrey, Ray; Dahl, Sarah

    2006-05-01

    There is a growing international recognition of the importance of the early years of schooling as well as an interest being shown in the relationship of early education to later achievement. This article focuses on a cohort of English pupils who have been tracked through primary school during the first five years of the new National Numeracy Strategy. It reports a limited longitudinal study of young children's early mathematical development, initially within three testing cycles: at the mid-point and towards the end of their reception year (at five years-of-age) and again at the mid-point of Year 1 (at six years-ofage). These cycles were located within the broader context of progress through to the end of Key Stage 1 (at seven years) and Key Stage 2 (at eleven years) on the basis of national standardised assessment tests (SATs). Results showed that children who bring into school early mathematical knowledge do appear to be advantaged in terms of their mathematical progress through primary school. Numerical attainment increases in importance across the primary years and practical problem solving remains an important element of this. This finding is significant given the current emphasis on numerical calculation in the English curriculum. It is concluded that without active intervention, it is likely that children with little mathematical knowledge at the beginning of formal schooling will remain low achievers throughout their primary years and, probably, beyond.

  9. Fostering Early Math Comprehension: Experimental Evidence from Paraguay

    Science.gov (United States)

    Naslund-Hadley, Emma; Parker, Susan W.; Hernandez-Agramonte, Juan Manuel

    2014-01-01

    Research indicates that preschool children need to learn pre-math skills to build a foundation for primary- and secondary-level mathematics. This paper presents the results from the early stages of a pilot mathematics program implemented in Cordillera, Paraguay. In a context of significant gaps in teacher preparation and pedagogy, the program uses…

  10. Early sexual debut: Voluntary or coerced? Evidence from ...

    African Journals Online (AJOL)

    Early sexual debut among young women and men. (commonly defined as having had first sexual intercourse at or before age 14 years) is associated with risks to sexual and reproductive health. These include risky sexual behaviours such as multiple partners, sex under the influence of alcohol or drugs, unplanned ...

  11. After runaway: The trans-Hill stage of planetesimal growth

    International Nuclear Information System (INIS)

    Lithwick, Yoram

    2014-01-01

    When planetesimals begin to grow by coagulation, they first enter an epoch of runaway, during which the biggest bodies grow faster than all the others. The questions of how runaway ends and what comes next have not been answered satisfactorily. We show that runaway is followed by a new stage—the 'trans-Hill stage'—that commences when the bodies that dominate viscous stirring ('big bodies') become trans-Hill, i.e., when their Hill velocity matches the random speed of the small bodies they accrete. Subsequently, the small bodies' random speed grows in lockstep with the big bodies' sizes, such that the system remains in the trans-Hill state. Trans-Hill growth is crucial for determining the efficiency of growing big bodies, as well as their growth timescale and size spectrum. Trans-Hill growth has two sub-stages. In the earlier one, which occurs while the stirring bodies remain sufficiently small, the evolution is collisionless, i.e., collisional cooling among all bodies is irrelevant. The efficiency of forming big bodies in this collisionless sub-stage is very low, ∼10α << 1, where α ∼ 0.005(a/AU) –1 is the ratio between the physical size of a body and its Hill radius. Furthermore, the size spectrum is flat (equal mass per size decade, i.e., q = 4). This collisionless trans-Hill solution explains results from previous coagulation simulations for both the Kuiper Belt and the asteroid belt. The second trans-Hill sub-stage commences once the stirring bodies grow big enough (>α –1 × the size of the accreted small bodies). After that time, collisional cooling among small bodies controls the evolution. The efficiency of forming big bodies rises and the size spectrum becomes more top heavy. Trans-Hill growth can terminate in one of two ways, depending on the sizes of the small bodies. First, mutual accretion of big bodies can become significant and conglomeration proceeds until half of the total mass is converted into big bodies

  12. Isotopic Evidence for Early Trade in Animals between Old Kingdom Egypt and Canaan.

    Science.gov (United States)

    Arnold, Elizabeth R; Hartman, Gideon; Greenfield, Haskel J; Shai, Itzhaq; Babcock, Lindsay E; Maeir, Aren M

    2016-01-01

    Isotope data from a sacrificial ass and several ovicaprines (sheep/goat) from Early Bronze Age household deposits at Tell es-Safi/Gath, Israel provide direct evidence for the movement of domestic draught/draft and husbandry animals between Old Kingdom Egypt (during the time of the Pyramids) and Early Bronze Age III Canaan (ca. 2900-2500 BCE). Vacillating, bi-directional connections between Egypt and Canaan are known throughout the Early Bronze Age, but here we provide the first concrete evidence of early trade in animals from Egypt to Canaan.

  13. Isotopic Evidence for Early Trade in Animals between Old Kingdom Egypt and Canaan.

    Directory of Open Access Journals (Sweden)

    Elizabeth R Arnold

    Full Text Available Isotope data from a sacrificial ass and several ovicaprines (sheep/goat from Early Bronze Age household deposits at Tell es-Safi/Gath, Israel provide direct evidence for the movement of domestic draught/draft and husbandry animals between Old Kingdom Egypt (during the time of the Pyramids and Early Bronze Age III Canaan (ca. 2900-2500 BCE. Vacillating, bi-directional connections between Egypt and Canaan are known throughout the Early Bronze Age, but here we provide the first concrete evidence of early trade in animals from Egypt to Canaan.

  14. Isotopic Evidence for Early Trade in Animals between Old Kingdom Egypt and Canaan

    Science.gov (United States)

    Greenfield, Haskel J.; Shai, Itzhaq; Babcock, Lindsay E.; Maeir, Aren M.

    2016-01-01

    Isotope data from a sacrificial ass and several ovicaprines (sheep/goat) from Early Bronze Age household deposits at Tell es-Safi/Gath, Israel provide direct evidence for the movement of domestic draught/draft and husbandry animals between Old Kingdom Egypt (during the time of the Pyramids) and Early Bronze Age III Canaan (ca. 2900–2500 BCE). Vacillating, bi-directional connections between Egypt and Canaan are known throughout the Early Bronze Age, but here we provide the first concrete evidence of early trade in animals from Egypt to Canaan. PMID:27322197

  15. Early differential processing of material images: Evidence from ERP classification.

    Science.gov (United States)

    Wiebel, Christiane B; Valsecchi, Matteo; Gegenfurtner, Karl R

    2014-06-24

    Investigating the temporal dynamics of natural image processing using event-related potentials (ERPs) has a long tradition in object recognition research. In a classical Go-NoGo task two characteristic effects have been emphasized: an early task independent category effect and a later task-dependent target effect. Here, we set out to use this well-established Go-NoGo paradigm to study the time course of material categorization. Material perception has gained more and more interest over the years as its importance in natural viewing conditions has been ignored for a long time. In addition to analyzing standard ERPs, we conducted a single trial ERP pattern analysis. To validate this procedure, we also measured ERPs in two object categories (people and animals). Our linear classification procedure was able to largely capture the overall pattern of results from the canonical analysis of the ERPs and even extend it. We replicate the known target effect (differential Go-NoGo potential at frontal sites) for the material images. Furthermore, we observe task-independent differential activity between the two material categories as early as 140 ms after stimulus onset. Using our linear classification approach, we show that material categories can be differentiated consistently based on the ERP pattern in single trials around 100 ms after stimulus onset, independent of the target-related status. This strengthens the idea of early differential visual processing of material categories independent of the task, probably due to differences in low-level image properties and suggests pattern classification of ERP topographies as a strong instrument for investigating electrophysiological brain activity. © 2014 ARVO.

  16. Cool episodes in Early Tertiary Arctic climate: Evidence from Svalbard

    Science.gov (United States)

    Spielhagen, R. F.; Tripati, A.

    2009-04-01

    The Arctic is a climatically sensitive and important region. However, very little is known about the climatic and oceanographic evolution of the area, particularly prior to the Neogene. Until recently, the Arctic was assumed to be characterized by relatively warm conditions during the early Cenozoic. The Early Tertiary sedimentary sequence on Svalbard contains several layers with coal seams and broad-leaved plants which were commonly accepted as indicators of a generally temperate-warm climate. Here we report on the intermittent occurrence of certain temperature indicators in the succession, which may represent the first northern high-latitude record of near-freezing temperatures for the early Cenozoic. Besides the findings of probably ice-rafted erratic clasts in the Paleocene and Eocene sandstones and shales, we note especially the occurrence of glendonites which are pseudomorphs of calcite after ikaite (calcium carbonate hexahydrate). We measured the chemical composition of Svalbard glendonites which is almost identical to that of similar pseudomorphs from the Lower Cretaceaous of Northern Canada. Mass spectrometric analyses of the glendonite calcite gave very low carbon isotope values. These values suggest a provenance of the calcium carbonate from marine organic carbon and connect our glendonites to the precursor mineral ikaite which has similar low values. Since a variety of studies has demonstrated that ikaite is stable only at temperatures close to freezing point, we have to infer low temperatures also for the deepositional environment of which the sediments were deposited that now hold glendonites. These results imply the occurrence of cooling phases episodically during the warm background climate of the Paleocene and Eocene, suggesting that temperature variability was much greater than previously recognized.

  17. Fostering Early Math Comprehension: Experimental Evidence from Paraguay

    Directory of Open Access Journals (Sweden)

    Emma Naslund-Hadley

    2014-11-01

    Full Text Available Research indicates that preschool children need to learn pre-math skills to build a foundation for primary- and secondary-level mathematics. This paper presents the results from the early stages of a pilot mathematics program implemented in Cordillera, Paraguay. In a context of significant gaps in teacher preparation and pedagogy, the program uses interactive audio segments that cover the entire preschool math curriculum. Since Paraguayan classrooms tend to be bilingual, the audio and written materials use a combination of Spanish and Guaraní. Based on an experimental evaluation since the program’s implementation, we document positive and significant improvements of 0.16 standard deviations in standardized test scores. The program helped narrow learning gaps between low- and high-performing students, and between students with trained teachers and those whose teachers lack formal training in early childhood education. Moreover, the program improved learning equally among both Guaraní- and Spanish-speaking students. But not all learning gaps narrowed as a result of the program. Although girls improved significantly, boys improved much more, ultimately increasing the gender gap. To close this gender gap, the program has been modified to encourage girls’ increased participation in the classroom and general interest in math

  18. Early African Diaspora in colonial Campeche, Mexico: strontium isotopic evidence.

    Science.gov (United States)

    Price, T Douglas; Tiesler, Vera; Burton, James H

    2006-08-01

    Construction activities around Campeche's central park led to the discovery of an early colonial church and an associated burial ground, in use from the mid-16th century AD to the late 17th century. Remains of some individuals revealed dental mutilations characteristic of West Africa. Analyses of strontium isotopes of dental enamel from these individuals yielded unusually high (87)Sr/(86)Sr ratios, inconsistent with an origin in Mesoamerica, but consistent with an origin in West Africa in terrain underlain by the West Africa Craton, perhaps near the port of Elmina, a principal source of slaves for the New World during the 16th century. These individuals likely represent some of the earliest representatives of the African Diaspora in the Americas.

  19. Molecular evidence for the early history of living amphibians.

    Science.gov (United States)

    Feller, A E; Hedges, S B

    1998-06-01

    The evolutionary relationships of the three orders of living amphibians (lissamphibians) has been difficult to resolve, partly because of their specialized morphologies. Traditionally, frogs and salamanders are considered to be closest relatives, and all three orders are thought to have arisen in the Paleozoic (>250 myr). Here, we present evidence from the DNA sequences of four mitochondrial genes (2.7 kilobases) that challenges the conventional hypothesis and supports a salamander-caecilian relationship. This, in light of the fossil record and distribution of the families, suggests a more recent (Mesozoic) origin for salamanders and caecilians directly linked to the initial breakup of the supercontinent Pangaea. We propose that this single geologic event isolated salamanders and archaeobatrachian frogs on the northern continents (Laurasia) and the caecilians and neobatrachian frogs on the southern continents (Gondwana). Among the neobatrachian frog families, molecular evidence supports a South American clade and an African clade, inferred here to be the result of mid-Cretaceous vicariance. Copyright 1998 Academic Press.

  20. Counseling women with early pregnancy failure: utilizing evidence, preserving preference.

    Science.gov (United States)

    Wallace, Robin R; Goodman, Suzan; Freedman, Lori R; Dalton, Vanessa K; Harris, Lisa H

    2010-12-01

    To apply principles of shared decision-making to EPF management counseling. To present a patient treatment priority checklist developed from review of available literature on patient priorities for EPF management. Review of evidence for patient preferences; personal, emotional, physical and clinical factors that may influence patient priorities for EPF management; and the clinical factors, resources, and provider bias that may influence current practice. Women have strong and diverse preferences for EPF management and report higher satisfaction when treated according to these preferences. However, estimates of actual treatment patterns suggest that current practice does not reflect the evidence for safety and acceptability of all options, or patient preferences. Multiple practice barriers and biases exist that may be influencing provider counseling about options for EPF management. Choosing management for EPF is a preference-sensitive decision. A patient-centered approach to EPF management should incorporate counseling about all treatment options. Providers can integrate a counseling model into EPF management practice that utilizes principles of shared decision-making and an organized method for eliciting patient preferences, priorities, and concerns about treatment options. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  1. Early Child Disaster Mental Health Interventions: A Review of the Empirical Evidence

    Science.gov (United States)

    Pfefferbaum, Betty; Nitiéma, Pascal; Tucker, Phebe; Newman, Elana

    2017-01-01

    Background: The need to establish an evidence base for early child disaster interventions has been long recognized. Objective: This paper presents a descriptive analysis of the empirical research on early disaster mental health interventions delivered to children within the first 3 months post event. Methods: Characteristics and findings of the…

  2. Proterozoic and early Cambrian protists: evidence for accelerating evolutionary tempo

    Science.gov (United States)

    Knoll, A. H.

    1994-01-01

    In rocks of late Paleoproterozoic and Mesoproterozoic age (ca. 1700-1000 million years ago), probable eukaryotic microfossils are widespread and well preserved, but assemblage and global diversities are low and turnover is slow. Near the Mesoproterozoic-Neoproterozoic boundary (1000 million years ago), red, green, and chromophytic algae diversified; molecular phylogenies suggest that this was part of a broader radiation of "higher" eukaryotic phyla. Observed diversity levels for protistan microfossils increased significantly at this time, as did turnover rates. Coincident with the Cambrian radiation of marine invertebrates, protistan microfossils again doubled in diversity and rates of turnover increased by an order of magnitude. Evidently, the Cambrian diversification of animals strongly influenced evolutionary rates, within clades already present in marine communities, implying an important role for ecology in fueling a Cambrian explosion that extends across kingdoms.

  3. PLANETESIMAL AND PROTOPLANET DYNAMICS IN A TURBULENT PROTOPLANETARY DISK: IDEAL UNSTRATIFIED DISKS

    International Nuclear Information System (INIS)

    Yang, Chao-Chin; Mac Low, Mordecai-Mark; Menou, Kristen

    2009-01-01

    The dynamics of planetesimals and planetary cores may be strongly influenced by density perturbations driven by magneto-rotational turbulence in their natal protoplanetary gas disks. Using the local shearing box approximation, we perform numerical simulations of planetesimals moving as massless particles in a turbulent, magnetized, unstratified gas disk. Our fiducial disk model shows turbulent accretion characterized by a Shakura-Sunyaev viscosity parameter of α ∼ 10 -2 , with rms density perturbations of ∼10%. We measure the statistical evolution of particle orbital properties in our simulations including mean radius, eccentricity, and velocity dispersion. We confirm random walk growth in time of all three properties, the first time that this has been done with direct orbital integration in a local model. We find that the growth rate increases with the box size used at least up to boxes of eight scale heights in horizontal size. However, even our largest boxes show velocity dispersions sufficiently low that collisional destruction of planetesimals should be unimportant in the inner disk throughout its lifetime. Our direct integrations agree with earlier torque measurements showing that type I migration dominates over diffusive migration by stochastic torques for most objects in the planetary core and terrestrial planet mass range. Diffusive migration remains important for objects in the mass range of kilometer-sized planetesimals. Discrepancies in the derived magnitude of turbulence between local and global simulations of magneto-rotationally unstable disks remains an open issue, with important consequences for planet formation scenarios.

  4. Studies of Planet Formation using a Hybrid N-body + Planetesimal Code

    Science.gov (United States)

    Kenyon, Scott J.; Bromley, Benjamin C.; Salamon, Michael (Technical Monitor)

    2005-01-01

    The goal of our proposal was to use a hybrid multi-annulus planetesimal/n-body code to examine the planetesimal theory, one of the two main theories of planet formation. We developed this code to follow the evolution of numerous 1 m to 1 km planetesimals as they collide, merge, and grow into full-fledged planets. Our goal was to apply the code to several well-posed, topical problems in planet formation and to derive observational consequences of the models. We planned to construct detailed models to address two fundamental issues: 1) icy planets - models for icy planet formation will demonstrate how the physical properties of debris disks, including the Kuiper Belt in our solar system, depend on initial conditions and input physics; and 2) terrestrial planets - calculations following the evolution of 1-10 km planetesimals into Earth-mass planets and rings of dust will provide a better understanding of how terrestrial planets form and interact with their environment. During the past year, we made progress on each issue. Papers published in 2004 are summarized. Summaries of work to be completed during the first half of 2005 and work planned for the second half of 2005 are included.

  5. Dispersion of the Himalia family of jovian irregular satellites by planetesimal encounters

    Science.gov (United States)

    Li, Daohai; Christou, Apostolos

    2017-06-01

    Giant planets are believed to have migrated significant radial distances due to interaction with a primordial planetesimal disk (Tsiganis et al. 2005). This process profoundly sculpted the solar system, shaping the distribution of the different types of heliocentric objects: the giant planets, the Trojans, the Main Asteroid Belt and the KBOs. Meanwhile, the same migration may have influenced the distribution of objects in the local planetocentric system as well. Since migration is achieved mainly by planet-planetesimal encounters, we focus on irregular satellites far from the host, thus susceptible to planetesimal perturbations. Specifically, we aim to reproduce a puzzling feature of the jovian Himalia group of prograde satellites: a wide spread in $a$ and $e$, with all group members being $>200$ m/s from Himalia and apparently too high to be consistent with a purely collisional origin. Here we investigate the evolution of a pre-existing Himalia group during planetary migration.We do this in a two-step procedure. Firstly, we perform migration simulations and record the states of planetesimals approaching Jupiter. Secondly, a nascent, closely-packed Himalia group with velocity dispersion of a few 10 m/s is integrated under the gravitational disturbance of the planetesimal fly-bys. We find that these planetesimal encounters disperse the group dramatically, bumping $\\sim 60\\%$ of the members to $>200$ m/s with respect to Himalia. Particularly, $a$ and $e$ suffer the most variation while the change in $i$ is often limited, matching the actual values for the observed group fairly well.Current models posit extensive collisional processing of the irregular satellite population following the planet migration phase (Bottke et al. 2010). In evaluating the collisional probability between a group member and Himalia, we find that the closer they are, the more likely that collisions occur. This suggests that members adjacent to Himalia are more likely to be collisionally

  6. Applying an Evidence-Based Framework to the Early Childhood Coaching Literature

    Science.gov (United States)

    Artman-Meeker, Kathleen; Fettig, Angel; Barton, Erin E.; Penney, Ashley; Zeng, Songtian

    2015-01-01

    Professional development (PD) is a critical pathway for promoting the use of evidence-based intervention practices in early childhood (EC) settings. Coaching has been proposed as a type of PD that is especially promising for job-embedded learning. A lack of consensus exists regarding evidence-based EC coaching strategies and what types of support…

  7. Meteoritic Evidence for Injection of Trans-Neptunian Objects into the Inner Solar System

    Science.gov (United States)

    Zolensky, M.; Johnson, J.; Ziegler, K.; Chan, Q.; Kebukawa, Y.; Bottke, W.; Fries, M.; Martinez, J.; Le, L.

    2018-01-01

    There is excellent evidence that a dynamical instability in the early solar system led to gravitational interactions between the giant planets and trans-Neptunian planetesimals. Giant planetary migration triggered by the instability dispersed a disk of primordial trans-Neptunian object (TNOs) and created a number of small body reservoirs (e.g. the Kuiper Belt, scattered disk, irregular satellites, and the Jupiter/Neptune Trojan populations). It also injected numerous bodies into the main asteroid belt, where modeling shows they can successfully reproduce the observed P and D-type asteroid populations.

  8. EVIDENCE FOR GRANULATION IN EARLY A-TYPE STARS

    International Nuclear Information System (INIS)

    Kallinger, Thomas; Matthews, Jaymie M.

    2010-01-01

    Stars with spectral types earlier than about F0 on (or close) to the main sequence have long been believed to lack observable surface convection, although evolutionary models of A-type stars do predict very thin surface convective zones. We present evidence for granulation in two δ Scuti stars of spectral type A2: HD 174936 and HD 50844. Recent analyses of space-based CoRoT data revealed up to some 1000 frequencies in the photometry of these stars. The frequencies were interpreted as individual pulsation modes. If true, there must be large numbers of nonradial modes of very high degree l which should suffer cancellation effects in disk-integrated photometry (even of high space-based precision). The p-mode interpretation of all the frequencies in HD 174936 and HD 50844 depends on the assumption of white (frequency-independent) noise. Our independent analyses of the data provide an alternative explanation: most of the peaks in the Fourier spectra are the signature of non-white granulation background noise, and less than about 100 of the frequencies are actual stellar p-modes in each star. We find granulation timescales which are consistent with scaling relations that describe cooler stars with known surface convection. If the granulation interpretation is correct, the hundreds of low-amplitude Fourier peaks reported in recent studies are falsely interpreted as independent pulsation modes and a significantly lower number of frequencies are associated with pulsation, consistent with only modes of low degree.

  9. Large-scale melting and impact mixing on early-formed asteroids

    DEFF Research Database (Denmark)

    Greenwood, Richard; Barrat, J.-A.; Scott, Edward Robert Dalton

    Large-scale melting of asteroids and planetesimals is now known to have taken place ex-tremely early in solar system history [1]. The first-generation bodies produced by this process would have been subject to rapid collisional reprocessing, leading in most cases to fragmentation and/or accretion...... the relationship between the different groups of achondrites [3, 4]. Here we present new oxygen isotope evidence con-cerning the role of large-scale melting and subsequent impact mixing in the evolution of three important achondrite groups: the main-group pallasites, meso-siderites and HEDs....

  10. PLANETESIMAL ACCRETION IN BINARY SYSTEMS: ROLE OF THE COMPANION'S ORBITAL INCLINATION

    International Nuclear Information System (INIS)

    Xie Jiwei; Zhou Jilin

    2009-01-01

    Recent observations show that planets can reside in close binary systems with stellar separation of only ∼20 AU. However, planet formation in such close binary systems is a challenge to current theory. One of the major theoretical problems occurs in the intermediate stage-planetesimals accretion into planetary embryos-during which the companion's perturbations can stir up the relative velocities (utriV) of planetesimals and thus slow down or even cease their growth. Recent studies have shown that conditions could be even worse for accretion if the gas-disk evolution was included. However, all previous studies assumed a two-dimensional disk and a coplanar binary orbit. Extending previous studies by including a three-dimensional gas disk and an inclined binary orbit with small relative inclination of i B = 0. 0 1-5 0 , we numerically investigate the conditions for planetesimal accretion at 1-2 AU, an extension of the habitable zone (∼1-1.3 AU), around α Centauri A in this paper. Inclusion of the binary inclination leads to the following: (1) differential orbital phasing is realized in the three-dimensional space, and thus different-sized bodies are separated from each other, (2) total impact rate is lower, and impacts mainly occur between similar-sized bodies, (3) accretion is more favored, but the balance between accretion and erosion remains uncertain, and the 'possible accretion region' extends up to 2 AU when assuming an optimistic Q* (critical specific energy that leads to catastrophic fragmentation), and (4) impact velocities (utriV) are significantly reduced but still much larger than their escape velocities, which infers that planetesimals grow by means of type II runaway mode. As a conclusion, the inclusion of a small binary inclination is a promising mechanism that favors accretion, opening a possibility that planet formation in close binary systems can go through the difficult stage of planetesimals accretion into planetary embryos.

  11. Early management of acute pancreatitis: A review of the best evidence.

    Science.gov (United States)

    Stigliano, Serena; Sternby, Hanna; de Madaria, Enrique; Capurso, Gabriele; Petrov, Maxim S

    2017-06-01

    In the 20th century early management of acute pancreatitis often included surgical intervention, despite overwhelming mortality. The emergence of high-quality evidence (randomized controlled trials and meta-analyses) over the past two decades has notably shifted the treatment paradigm towards predominantly non-surgical management early in the course of acute pancreatitis. The present evidence-based review focuses on contemporary aspects of early management (which include analgesia, fluid resuscitation, antibiotics, nutrition, and endoscopic retrograde cholangiopancreatography) with a view to providing clear and succinct guidelines on early management of patients with acute pancreatitis in 2017 and beyond. Copyright © 2017 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  12. Intraoperative radiotherapy in early stage breast cancer: potential indications and evidence to date

    Science.gov (United States)

    Kirby, A M

    2015-01-01

    Following early results of recent studies of intraoperative radiotherapy (IORT) in the adjuvant treatment of patients with early breast cancer, the clinical utility of IORT is a subject of much recent debate within the breast oncology community. This review describes the intraoperative techniques available, the potential indications and the evidence to date pertaining to local control and toxicity. We also discuss any implications for current practice and future research. PMID:25734489

  13. Early Bronze Age Houses in Upper Mesopotamia: Evidence of Dwellings or Private Enterprises?

    OpenAIRE

    Mas, Juliette

    2014-01-01

    This paper deals with the research I carried out on domestic architecture and private economy during Early Bronze Age in Upper-Mesopotamia. Archaeological records, as well as textual evidence, has been used to try to define private households activities and their relationships with official institutions. Households were the main source of production, distribution and consumption during the Early Bronze Age. As it seems that these private economic entities produced goods and crafts in their ow...

  14. The Formation of Jupiter, the Jovian Early Bombardment and the Delivery of Water to the Asteroid Belt: The Case of (4) Vesta

    Science.gov (United States)

    Turrini, Diego; Svetsov, Vladimir

    2014-01-01

    The asteroid (4) Vesta, parent body of the Howardite-Eucrite-Diogenite meteorites, is one of the first bodies that formed, mostly from volatile-depleted material, in the Solar System. The Dawn mission recently provided evidence that hydrated material was delivered to Vesta, possibly in a continuous way, over the last 4 Ga, while the study of the eucritic meteorites revealed a few samples that crystallized in presence of water and volatile elements. The formation of Jupiter and probably its migration occurred in the period when eucrites crystallized, and triggered a phase of bombardment that caused icy planetesimals to cross the asteroid belt. In this work, we study the flux of icy planetesimals on Vesta during the Jovian Early Bombardment and, using hydrodynamic simulations, the outcome of their collisions with the asteroid. We explore how the migration of the giant planet would affect the delivery of water and volatile materials to the asteroid and we discuss our results in the context of the geophysical and collisional evolution of Vesta. In particular, we argue that the observational data are best reproduced if the bulk of the impactors was represented by 1–2 km wide planetesimals and if Jupiter underwent a limited (a fraction of au) displacement. PMID:25370027

  15. The Formation of Jupiter, the Jovian Early Bombardment and the Delivery of Water to the Asteroid Belt: The Case of (4 Vesta

    Directory of Open Access Journals (Sweden)

    Diego Turrini

    2014-01-01

    Full Text Available The asteroid (4 Vesta, parent body of the Howardite-Eucrite-Diogenite meteorites, is one of the first bodies that formed, mostly from volatile-depleted material, in the Solar System. The Dawn mission recently provided evidence that hydrated material was delivered to Vesta, possibly in a continuous way, over the last 4 Ga, while the study of the eucritic meteorites revealed a few samples that crystallized in presence of water and volatile elements. The formation of Jupiter and probably its migration occurred in the period when eucrites crystallized, and triggered a phase of bombardment that caused icy planetesimals to cross the asteroid belt. In this work, we study the flux of icy planetesimals on Vesta during the Jovian Early Bombardment and, using hydrodynamic simulations, the outcome of their collisions with the asteroid. We explore how the migration of the giant planet would affect the delivery of water and volatile materials to the asteroid and we discuss our results in the context of the geophysical and collisional evolution of Vesta. In particular, we argue that the observational data are best reproduced if the bulk of the impactors was represented by 1–2 km wide planetesimals and if Jupiter underwent a limited (a fraction of au displacement.

  16. Increases to Inferred Rates of Planetesimal Accretion due to Thermohaline Mixing in Metal-accreting White Dwarfs

    Science.gov (United States)

    Bauer, Evan B.; Bildsten, Lars

    2018-06-01

    Many isolated, old white dwarfs (WDs) show surprising evidence of metals in their photospheres. Given that the timescale for gravitational sedimentation is astronomically short, this is taken as evidence for ongoing accretion, likely of tidally disrupted planetesimals. The rate of such accretion, {\\dot{M}}acc}, is important to constrain, and most modeling of this process relies on assuming an equilibrium between diffusive sedimentation and metal accretion supplied to the WD’s surface convective envelope. Building on the earlier work of Deal and collaborators, we show that high {\\dot{M}}acc} models with only diffusive sedimentation are unstable to thermohaline mixing and that models that account for the enhanced mixing from the active thermohaline instability require larger accretion rates, sometimes reaching {\\dot{M}}acc}≈ {10}13 {{g}} {{{s}}}-1 to explain observed calcium abundances. We present results from a grid of MESA models that include both diffusion and thermohaline mixing. These results demonstrate that both mechanisms are essential for understanding metal pollution across the range of polluted WDs with hydrogen atmospheres. Another consequence of active thermohaline mixing is that the observed metal abundance ratios are identical to accreted material.

  17. Iron 60 Evidence for Early Injection and Efficient Mixing of Stellar Debris in the Protosolar Nebula

    International Nuclear Information System (INIS)

    Dauphas, N.; Sacarabany, A.; Davis, A. M.; Pourmand, A.; Cook, D. L.; Froehlich, C.; Wadhwa, M.; Rauscher, T.; Gallino, R.

    2008-01-01

    Among extinct radioactivities present in meteorites, 60 Fe (t 1/2 = 1.49 Myr) plays a key role as a high-resolution chronometer, a heat source in planetesimals, and a fingerprint of the astrophysical setting of solar system formation. A critical issue with 60 Fe is that it could have been heterogeneously distributed in the protoplanetary disk, calling into question the efficiency of mixing in the solar nebula or the timing of 60 Fe injection relative to planetesimal formation. If this were the case, one would expect meteorites that did not incorporate 60 Fe (either because of late injection or incomplete mixing) to show 60 Ni deficits (from lack of 60 Fe decay) and collateral effects on other neutron-rich isotopes of Fe and Ni (coproduced with 60 Fe in core-collapse supernovae and AGB stars). Here, we show that measured iron meteorites and chondrites have Fe and Ni isotopic compositions identical to Earth. This demonstrates that 60 Fe must have been injected into the protosolar nebula and mixed to less than 10% heterogeneity before formation of planetary bodies.

  18. X-ray photoevaporation's limited success in the formation of planetesimals by the streaming instability

    Science.gov (United States)

    Ercolano, Barbara; Jennings, Jeff; Rosotti, Giovanni; Birnstiel, Tilman

    2017-12-01

    The streaming instability is often invoked as solution to the fragmentation and drift barriers in planetesimal formation, catalysing the aggregation of dust on kyr time-scales to grow km-sized cores. However, there remains a lack of consensus on the physical mechanism(s) responsible for initiating it. One potential avenue is disc photoevaporation, wherein the preferential removal of relatively dust-free gas increases the disc metallicity. Late in the disc lifetime, photoevaporation dominates viscous accretion, creating a gradient in the depleted gas surface density near the location of the gap. This induces a local pressure maximum that collects drifting dust particles, which may then become susceptible to the streaming instability. Using a one-dimensional viscous evolution model of a disc subject to internal X-ray photoevaporation, we explore the efficacy of this process to build planetesimals. Over a range of parameters, we find that the amount of dust mass converted into planetesimals is often planetary cores. Our results are in contrast to a recent, similar investigation that considered an far-ultra-violet (FUV)-driven photoevaporation model and reported the formation of tens of M⊕ at large (>100 au) disc radii. The discrepancies are primarily a consequence of the different photoevaporation profiles assumed. Until observations more tightly constrain photoevaporation models, the relevance of this process to the formation of planets remains uncertain.

  19. Evidence Supporting an Early as Well as Late Heavy Bombardment on the Moon

    Science.gov (United States)

    Frey, Herbert

    2015-01-01

    Evidence supporting an intense early bombardment on the Moon in addition to the traditional Late Heavy Bombardment at approx. 4 BY ago include the distribution of N(50) Crater Retention Ages (CRAs) for candidate basins, a variety of absolute age scenarios for both a "young" and an "old" Nectaris age, and the decreasing contrasts in both topographic relief and Bouguer gravity with increasing CRA.

  20. Evidence of Effectiveness of Current Therapies to Prevent and Treat Early Childhood Caries

    DEFF Research Database (Denmark)

    Twetman, Svante; Dhar, Vineet

    2015-01-01

    PURPOSE: The purpose of this paper was to systematically review the quality of evidence related to self-applied and professionally applied fluorides, antimicrobial agents, fissure sealants, temporary restorations, and restorative care for the prevention and management of early childhood caries (E...

  1. Promoting Evidence-Based Practices: New Teaching Module for Early Childhood Teacher Educators

    Science.gov (United States)

    Young Children, 2009

    2009-01-01

    Linda Halgunseth, head of NAEYC's Office of Applied Research (OAR), tells readers about Child Care and Early Education Research Connections, a Web site (www.researchconnections.org/teaching_modules) to help teacher educators integrate knowledge about evidence-based practices into teacher education programs. In addition, the article touts the…

  2. Silicon isotopes in angrites and volatile loss in planetesimals

    OpenAIRE

    Pringle, Emily A.; Moynier, Frédéric; Savage, Paul S.; Badro, James; Barrat, Jean-Alix

    2014-01-01

    Understanding volatile elements in the early solar system is a key step toward understanding the processes of planetary formation and the composition of Earth, but the origin of volatiles on Earth is not well understood. In this article, we present measurements of silicon isotope ratios in angrites, a class of meteorites dating from the first few million years after condensation of solids from the solar nebula. We show that the silicon isotope composition of angrites is consistent with a depl...

  3. Early Middle Formative Occupation in the Central Maya Lowlands: Recent Evidence from Cahal Pech, Belize

    Directory of Open Access Journals (Sweden)

    Jaime Awe

    1990-11-01

    Full Text Available After more than half a century of intensive archaeological research the early Middle Formative (or Middle Preclassic period (1000-600 B.C. continues to be one of the most enigmatic eras in the study of Lowland Maya prehistory. While several factors contribte to this situation, the primary cause for this obscurity lies in the fact that few sites have produced either contextual or stratigraphic evidence of occupation during this phase (Rice 1976; Andrews 1988. Concsequently, any new site with evidence of Middle Formative occupation can contribute substantially to our limited knowledge of this pioneering stage of the lowland Maya. This paper introduces one such site, Cahal Pech, where recent investigations have uncovered a stratigraphic sequence that tentatively spans the early Middle Formative to the Late Classic period. It provides a preliminary description, of the site's early Middle Formative configuration and briefly discusses its possible regional affiliation.

  4. The Early Anthropogenic Hypothesis: Top-Down and Bottom-up Evidence

    Science.gov (United States)

    Ruddiman, W. F.

    2014-12-01

    Two complementary lines of evidence support the early anthropogenic hypothesis. Top-down evidence comes from comparing Holocene greenhouse-gas trends with those during equivalent intervals of previous interglaciations. The increases in CO2 and CH4 during the late Holocene are anomalous compared to the decreasing trends in a stacked average of previous interglaciations, thereby supporting an anthropogenic origin. During interglacial stage 19, the closest Holocene insolation analog, CO2 fell to 245 ppm by the time equivalent to the present, in contrast to the observed pre-industrial rise to 280-285 ppm. The 245-ppm level measured in stage 19 falls at the top of the natural range predicted by the original anthropogenic hypothesis of Ruddiman (2003). Bottom-up evidence comes from a growing list of archeological and other compilations showing major early anthropogenic transformations of Earth's surface. Key examples include: efforts by Dorian Fuller and colleagues mapping the spread of irrigated rice agriculture across southern Asia and its effects on CH4 emissions prior to the industrial era; an additional effort by Fuller showing the spread of methane-emitting domesticated livestock across Asia and Africa (coincident with the spread of fertile crescent livestock across Europe); historical compilations by Jed Kaplan and colleagues documenting very high early per-capita forest clearance in Europe, thus underpinning simulations of extensive pre-industrial clearance and large CO2 emissions; and wide-ranging studies by Erle Ellis and colleagues of early anthropogenic land transformations in China and elsewhere.

  5. Does evidence really matter? Professionals’ opinions on the practice of early mobilization after stroke

    Science.gov (United States)

    Sjöholm, Anna; Skarin, Monica; Linden, Thomas; Bernhardt, Julie

    2011-01-01

    Introduction: Early mobilization after stroke may be important for a good outcome and it is currently recommended in a range of international guidelines. The evidence base, however, is limited and clear definitions of what constitutes early mobilization are lacking. Aims: To explore stroke care professionals’ opinions about (1) when after stroke, first mobilization should take place, (2) whether early mobilization may affect patients’ final outcome, and (3) what level of evidence they require to be convinced that early mobilization is beneficial. Methods: A nine-item questionnaire was used to interview stroke care professionals during a conference in Sydney, Australia. Results: Among 202 professionals interviewed, 40% were in favor of mobilizing both ischemic and hemorrhagic stroke patients within 24 hours of stroke onset. There was no clear agreement about the optimal time point beyond 24 hours. Most professionals thought that patients’ final motor outcome (76%), cognitive outcome (57%), and risk of depression (75%) depends on being mobilized early. Only 19% required a large randomized controlled trial or a systematic review to be convinced of benefit. Conclusion: The spread in opinion reflects the absence of clear guidelines and knowledge in this important area of stroke recovery and rehabilitation, which suggests further research is required. PMID:22096341

  6. Predictive information processing is a fundamental learning mechanism present in early development: evidence from infants.

    Science.gov (United States)

    Trainor, Laurel J

    2012-02-01

    Evidence is presented that predictive coding is fundamental to brain function and present in early infancy. Indeed, mismatch responses to unexpected auditory stimuli are among the earliest robust cortical event-related potential responses, and have been measured in young infants in response to many types of deviation, including in pitch, timing, and melodic pattern. Furthermore, mismatch responses change quickly with specific experience, suggesting that predictive coding reflects a powerful, early-developing learning mechanism. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Morphological and genetic evidence for early Holocene cattle management in northeastern China

    DEFF Research Database (Denmark)

    Zhang, Hucai; Paijmans, Johanna L. A.; Chang, Fengqin

    2013-01-01

    The domestication of cattle is generally accepted to have taken place in two independent centres: around 10,500 years ago in the Near East, giving rise to modern taurine cattle, and two millennia later in southern Asia, giving rise to zebu cattle. Here we provide firmly dated morphological...... and genetic evidence for early Holocene management of taurine cattle in northeastern China. We describe conjoining mandibles from this region that show evidence of oral stereotypy, dated to the early Holocene by two independent (14)C dates. Using Illumina high-throughput sequencing coupled with DNA...... hybridization capture, we characterize 15,406 bp of the mitogenome with on average 16.7-fold coverage. Phylogenetic analyses reveal a hitherto unknown mitochondrial haplogroup that falls outside the known taurine diversity. Our data suggest that the first attempts to manage cattle in northern China predate...

  8. Utilisation of evidence-based practices by ASD early intervention service providers.

    Science.gov (United States)

    Paynter, Jessica M; Ferguson, Sarah; Fordyce, Kathryn; Joosten, Annette; Paku, Sofia; Stephens, Miranda; Trembath, David; Keen, Deb

    2017-02-01

    A number of autism intervention practices have been demonstrated to be effective. However, the use of unsupported practices persists in community early intervention settings. Recent research has suggested that personal, professional and workplace factors may influence intervention choices. The aim of this research was to investigate knowledge and use of strategies, organisational culture, individual attitudes, sources of information and considerations informing intervention choices by early intervention providers. An online survey was completed by 72 early intervention providers from four organisations across Australia. Providers reported high levels of trust and access of information from internal professional development, therapists and external professional development. A range of considerations including child factors, family values and research were rated as important in informing intervention choices. Participants reported greater knowledge and use of evidence-based and emerging practices than unsupported. Levels of use were linked to levels of knowledge, as well as some organisational and attitudinal factors. Areas for future research and implications are discussed.

  9. More evidence for a one-to-one correlation between Sprites and Early VLF perturbations

    Science.gov (United States)

    Haldoupis, C.; Amvrosiadi, N.; Cotts, B. R. T.; van der Velde, O. A.; Chanrion, O.; Neubert, T.

    2010-07-01

    Past studies have shown a correlation between sprites and early VLF perturbations, but the reported correlation varies widely from ˜50% to 100%. The present study resolves these large discrepancies by analyzing several case studies of sprite and narrowband VLF observations, in which multiple transmitter-receiver VLF pairs with great circle paths (GCPs) passing near a sprite-producing thunderstorm were available. In this setup, the multiple paths act in a complementary way that makes the detection of early VLF perturbations much more probable compared to a single VLF path that can miss several of them, a fact that was overlooked in past studies. The evidence shows that visible sprite occurrences are accompanied by early VLF perturbations in a one-to-one correspondence. This implies that the sprite generation mechanism may cause also sub-ionospheric conductivity disturbances that produce early VLF events. However, the one-to-one visible sprite to early VLF event correspondence, if viewed conversely, appears not to be always reciprocal. This is because the number of early events detected in some case studies was considerably larger than the number of visible sprites. Since the great majority of the early events not accompanied by visible sprites appeared to be caused by positive cloud to ground (+CG) lightning discharges, it is possible that sprites or sprite halos were concurrently present in these events as well but were missed by the sprite-watch camera detection system. In order for this option to be resolved we need more studies using highly sensitive optical systems capable of detecting weaker sprites, sprite halos and elves.

  10. No evidence of early head circumference enlargements in children later diagnosed with autism in Israel.

    Science.gov (United States)

    Dinstein, Ilan; Haar, Shlomi; Atsmon, Shir; Schtaerman, Hen

    2017-01-01

    Large controversy exists regarding the potential existence and clinical significance of larger brain volumes in toddlers who later develop autism. Assessing this relationship is important for determining the clinical utility of early head circumference (HC) measures and for assessing the validity of the early overgrowth hypothesis of autism, which suggests that early accelerated brain development may be a hallmark of the disorder. We performed a retrospective comparison of HC, height, and weight measurements between 66 toddlers who were later diagnosed with autism and 66 matched controls. These toddlers represent an unbiased regional sample from a single health service provider in the southern district of Israel. On average, participating toddlers had >8 measurements between birth and the age of two, which enabled us to characterize individual HC, height, and weight development with high precision and fit a negative exponential growth model to the data of each toddler with exceptional accuracy. The analyses revealed that HC sizes and growth rates were not significantly larger in toddlers with autism even when stratifying the autism group based on verbal capabilities at the time of diagnosis. In addition, there were no significant correlations between ADOS scores at the time of diagnosis and HC at any time-point during the first 2 years of life. These negative results add to accumulating evidence, which suggest that brain volume is not necessarily larger in toddlers who develop autism. We believe that conflicting results reported in other studies are due to small sample sizes, use of misleading population norms, changes in the clinical definition of autism over time, and/or inclusion of individuals with syndromic autism. While abnormally large brains may be evident in some individuals with autism and more clearly visible in MRI scans, converging evidence from this and other studies suggests that enlarged HC is not a common etiology of the entire autism population

  11. Low velocity collisions of porous planetesimals in the early solar system

    Science.gov (United States)

    de Niem, D.; Kührt, E.; Hviid, S.; Davidsson, B.

    2018-02-01

    The ESA Rosetta mission has shown that Comet 67P/Churuymov-Gerasimenko is bi-lobed, has a high average porosity of around 70%, does not have internal cavities on size scales larger than 10 m, the lobes could have individual sets of onion shell-like layering, and the nucleus surface contains 100 m-scale cylindrical pits. It is currently debated whether these properties are consistent with high-velocity collisional evolution or if they necessarily are surviving signatures of low-velocity primordial accretion. We use an Eulerian hydrocode to study collisions between highly porous bodies of different sizes, material parameters and relative velocities with emphasis on 5-100 m/s to characterize the effects of collisions in terms of deformation, compaction, and heating. We find that accretion of 1 km cometesimals by 3 km nuclei at 13.5 m/s flattens and partially buries the cometesimal with ∼ 1% reduction of the bulk porosity. This structure locally becomes more dense but the global effect of compaction is minor, suggesting that low-velocity accretion does not lead to a 'bunch of grapes' structure with large internal cavities but a more homogeneous interior, consistent with Rosetta findings. The mild local compaction associated with accretion is potentially the origin of the observed nucleus layering. In 2D axially symmetric impacts hit-and-stick collisions of similarly-sized nuclei are possible at velocities up to 30 m/s where deformation becomes severe. The bulk porosity is reduced significantly, even at 30-50 m/s relative velocity. To avoid hit-and-run collisions the impact angle must be less than 35°-45° from the surface normal at 10 m/s, and even smaller at higher velocities. Impact heating is insignificant. We find that the small cross section of the 67P neck may require a ≤ 5 m/s impact, unless the cohesion exceeds 10 kPa. We conclude that bi-lobe nucleus formation is possible at velocities typically discussed in hierarchical growth scenarios. Impacts of a 7 m projectile at 100-500 m/s create a rimless cylindrical shaft with vertical walls, up to 50 m wide and 70 m deep. These shafts bear some resemblance with the pits on 67P, particularly if the depth-to-width ratio is reduced by nucleus erosion. Collisions between similarly-sized nuclei above 100 m/s lead to complete disintegration, and even small fragments suffer different degrees of compaction. Thus, we strongly doubt that 67P has been subjected to high-velocity collisions by projectiles larger than those that might have formed the pits, or is the fragment of a larger parent body. We suggest that the observed properties of 67P are more consistent with primordial accretion.

  12. Evidence of late Palaeocene-early Eocene equatorial rain forest refugia in southern Western Ghats, India.

    Science.gov (United States)

    Prasad, V; Farooqui, A; Tripathi, S K M; Garg, R; Thakur, B

    2009-11-01

    Equatorial rain forests that maintain a balance between speciation and extinction are hot-spots for studies of biodiversity. Western Ghats in southern India have gained attention due to high tropical biodiversity and endemism in their southern most area. We attempted to track the affinities of the pollen fl ora of the endemic plants of Western Ghat area within the fossil palynoflora of late Palaeocene-early Eocene (approximately 55-50 Ma) sedimentary deposits of western and northeastern Indian region. The study shows striking similarity of extant pollen with twenty eight most common fossil pollen taxa of the early Palaeogene. Widespread occurrences of coal and lignite deposits during early Palaeogene provide evidence of existence of well diversified rain forest community and swampy vegetation in the coastal low lying areas all along the western and northeastern margins of the Indian subcontinent. Prevalence of excessive humid climate during this period has been seen as a result of equatorial positioning of Indian subcontinent, superimposed by a long term global warming phase (PETM and EECO) during the early Palaeogene. The study presents clear evidence that highly diversifi ed equatorial rain forest vegetation once widespread in the Indian subcontinent during early Palaeogene times, are now restricted in a small area as a refugia in the southernmost part of the Western Ghat area. High precipitation and shorter periods of dry months seem to have provided suitable environment to sustain lineages of ancient tropical vegetation in this area of Western Ghats in spite of dramatic climatic changes subsequent to the post India-Asia collision and during the Quaternary and Recent times.

  13. Evidence for local and global redox conditions at an Early Ordovician (Tremadocian) mass extinction

    Science.gov (United States)

    Edwards, Cole T.; Fike, David A.; Saltzman, Matthew R.; Lu, Wanyi; Lu, Zunli

    2018-01-01

    Profound changes in environmental conditions, particularly atmospheric oxygen levels, are thought to be important drivers of several major biotic events (e.g. mass extinctions and diversifications). The early Paleozoic represents a key interval in the oxygenation of the ocean-atmosphere system and evolution of the biosphere. Global proxies (e.g. carbon (δ13C) and sulfur (δ34S) isotopes) are used to diagnose potential changes in oxygenation and infer causes of environmental change and biotic turnover. The Cambrian-Ordovician contains several trilobite extinctions (some are apparently local, but others are globally correlative) that are attributed to anoxia based on coeval positive δ13C and δ34S excursions. These extinction and excursion events have yet to be coupled with more recently developed proxies thought to be more reflective of local redox conditions in the water column (e.g. I/Ca) to confirm whether these extinctions were associated with oxygen crises over a regional or global scale. Here we examine an Early Ordovician (Tremadocian Stage) extinction event previously interpreted to reflect a continuation of recurrent early Paleozoic anoxic events that expanded into nearshore environments. δ13C, δ34S, and I/Ca trends were measured from three sections in the Great Basin region to test whether I/Ca trends support the notion that anoxia was locally present in the water column along the Laurentian margin. Evidence for anoxia is based on coincident, but not always synchronous, positive δ13C and δ34S excursions (mainly from carbonate-associated sulfate and less so from pyrite data), a 30% extinction of standing generic diversity, and near-zero I/Ca values. Although evidence for local water column anoxia from the I/Ca proxy broadly agrees with intervals of global anoxia inferred from δ13C and δ34S trends, a more complex picture is evident where spatially and temporally variable local trends are superimposed on time-averaged global trends. Stratigraphic

  14. The Maximum Mass Solar Nebula and the early formation of planets

    Science.gov (United States)

    Nixon, C. J.; King, A. R.; Pringle, J. E.

    2018-03-01

    Current planet formation theories provide successful frameworks with which to interpret the array of new observational data in this field. However, each of the two main theories (core accretion, gravitational instability) is unable to explain some key aspects. In many planet formation calculations, it is usual to treat the initial properties of the planet forming disc (mass, radius, etc.) as free parameters. In this paper, we stress the importance of setting the formation of planet forming discs within the context of the formation of the central stars. By exploring the early stages of disc formation, we introduce the concept of the Maximum Mass Solar Nebula (MMSN), as opposed to the oft-used Minimum Mass Solar Nebula (here mmsn). It is evident that almost all protoplanetary discs start their evolution in a strongly self-gravitating state. In agreement with almost all previous work in this area, we conclude that on the scales relevant to planet formation these discs are not gravitationally unstable to gas fragmentation, but instead form strong, transient spiral arms. These spiral arms can act as efficient dust traps allowing the accumulation and subsequent fragmentation of the dust (but not the gas). This phase is likely to populate the disc with relatively large planetesimals on short timescales while the disc is still veiled by a dusty-gas envelope. Crucially, the early formation of large planetesimals overcomes the main barriers remaining within the core accretion model. A prediction of this picture is that essentially all observable protoplanetary discs are already planet hosting.

  15. Formation of Non-symmetric Fractals During the First Stage of Pre-planetesimal Dust Growth

    Science.gov (United States)

    Kempf, S.; Blum, J.; Wurm, G.

    It is a generally accepted view that the genesis of a planetary system coincide s with the formation of sun-like young stellar objects surrounded by gaseous disc s. The building blocks of the planetesimals are micron-sized solid particles (the so-called dust) embedded in the gas of the disc. The relevant process for formi ng larger aggregates is the growth due to collisional sticking. For particles to c ollide and stick, a relative velocity component between the grains must be present. In the onset of dust growth, Brownian motion dominates other relative-velocity sources . However, numerically determined time scales of the pure Brownian dust growth are much too large for explaining the formation of planets within the lifetime of a proto-planetary di sc. In order to verify the validity of the theoretical models, the Cosmic Dust Aggr egation Experiment CODAG was developed. It allows to observe the growth of micron-sized dust analogs under astrophysical realistic conditions. Surprisingly, the experi ments showed that at least in the onset of the dust growth needle-like fractal aggreg ates rather than symmetric fractals are formed. Here we discuss the implication of this experimental finding for the pre-planetesimal growth models.

  16. Redox States of Initial Atmospheres Outgassed on Rocky Planets and Planetesimals

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Laura [Arizona State University, School of Earth and Space Exploration, Tempe, AZ 85287 (United States); Fegley, Bruce Jr., E-mail: lschaefer@asu.edu [Planetary Chemistry Laboratory, Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130 (United States)

    2017-07-10

    The Earth and other rocky planets and planetesimals in the solar system formed through the mixing of materials from various radial locations in the solar nebula. This primordial material likely had a range of oxidation states as well as bulk compositions and volatile abundances. We investigate the oxygen fugacity produced by the outgassing of mixtures of solid meteoritic material, which approximate the primitive nebular materials. We find that the gas composition and oxygen fugacity of binary and ternary mixtures of meteoritic materials vary depending on the proportion of reduced versus oxidized material, and also find that mixtures using differentiated materials do not show the same oxygen fugacity trends as those using similarly reduced but undifferentiated materials. We also find that simply mixing the gases produced by individual meteoritic materials together does not correctly reproduce the gas composition or oxygen fugacity of the binary and ternary mixtures. We provide tabulated fits for the oxygen fugacities of all of the individual materials and binary mixtures that we investigate. These values may be useful in planetary formation models, models of volatile transport on planetesimals or meteorite parent bodies, or models of trace element partitioning during metal-silicate fractionation.

  17. Planetesimal Formation in the Warm, Inner Disk: Experiments with Tempered Dust

    Energy Technology Data Exchange (ETDEWEB)

    De Beule, Caroline; Landers, Joachim; Salamon, Soma; Wende, Heiko; Wurm, Gerhard, E-mail: gerhard.wurm@uni-due.de [Faculty of Physics, University of Duisburg-Essen, Lotharstr. 1, D-47057 Duisburg (Germany)

    2017-03-01

    It is an open question how elevated temperatures in the inner parts of protoplanetary disks influence the formation of planetesimals. We approach this problem here by studying the tensile strength of granular beds with dust samples tempered at different temperatures. We find via laboratory experiments that tempering at increasing temperatures is correlated with an increase in cohesive forces. We studied dust samples of palagonite (JSC Mars-1a) which were tempered for up to 200 hr at temperatures between 600 and 1200 K, and measured the relative tensile strengths of highly porous dust layers once the samples cooled to room temperature. Tempering increases the tensile strength from 800 K upwards. This change is accompanied by mineral transformations, the formation of iron oxide crystallites as analyzed by Mössbauer spectroscopy, changes in the number size distribution, and the morphology of the surface visible as cracks in larger grains. These results suggest a difference in the collisional evolution toward larger bodies with increasing temperature as collisional growth is fundamentally based on cohesion. While high temperatures might also increase sticking (not studied here), compositional evolution will already enhance the cohesion and the possibility of growing larger aggregates on the way toward planetesimals. This might lead to a preferred in situ formation of inner planets and explain the observed presence of dense inner planetary systems.

  18. Evidence for and implications of an Early Archean terrestrial impact record

    International Nuclear Information System (INIS)

    Lowe, D.R.; Byerly, G.R.

    1988-01-01

    Early Archean, 3.5 to 3.2 Ga, greenstone sequences in South Africa and Western Australia contain a well-preserved record of early terrestrial meteorite impacts. The main impact-produced deposits are layers, 10 cm to over 1 m thick, composed largely of sand-sized spherules, 0.1 to 4 mm in diameter. The beds studied to date show an assemblage of features indicating formation by the fall of debris from impact-generated ejecta clouds. Some presented data effectively rule out normal magmatic or sedimentary processes in the origin of these units and provide substantial support for an origin by large impacts on the early earth. The presence of at least four, remarkably thick, nearly pure spherule layers suggests that smaller-scale impact deposits may be even more abundant in these sequences. The existence of a well-preserved Archean terrestrial impact record suggests that a direct source of evidence is available regarding a number of important aspects of early earth history

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

    Science.gov (United States)

    Vaiserman, Alexander M

    2017-03-05

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

  20. Evidence of Early Emergence of the Primary Dentition in a Northern Plains American Indian Population.

    Science.gov (United States)

    Dawson, D V; Blanchette, D R; Douglass, J M; Tinanoff, N; Kramer, K W O; Warren, J J; Phipps, K R; Starr, D E; Marshall, T A; Mabry, T R; Pagan-Rivera, K; Banas, J A; Drake, D R

    2018-04-01

    The purposes of this study were to describe primary tooth emergence in an American Indian (AI) population during the first 36 mo of life to compare 1) patterns of emergence between male and female children and 2) tooth emergence between these AI children and other U.S. ethnic groups. Data were derived from a birth cohort of 239 AI children from a Northern Plains tribe participating in a longitudinal study of early childhood caries, with examination data at target ages of 8, 12, 16, 22, 28, and 36 mo of age (±1 mo). Patterns of emergence in AI children were characterized and sex comparisons accomplished with interval-censored survival methodology. Numbers of erupted teeth in AI children at each age were compared via Kruskal-Wallis tests against those in children of the same age, as drawn from a cross-sectional study of dental caries patterns in Arizona; these comparisons were based on the dental examinations of 547 White non-Hispanic and 677 Hispanic children. Characterization of time to achievement of various milestones-including emergence of the anterior teeth, the first molars, and the complete primary dentition-provided no evidence of sex differences among AI children. AI children had significantly more teeth present at 8 mo (median, 3) than either White non-Hispanic ( P 0.05). These results provide evidence of earlier tooth emergence in AI children than in the other 2 ethnicities. Although the underlying etiology of the severity of early childhood caries in AI children is likely to be multifactorial, earlier tooth emergence may be a contributing factor. Knowledge Transfer Statement: The findings of this study have practical implications for practitioners providing childhood oral health care to ethnic groups with early tooth emergence. It may be important to provide parents with information on toothbrushing, dentist visits, and other practices supportive of good oral health as early as possible to protect their children's primary dentition.

  1. Multistage Core Formation in Planetesimals Revealed by Numerical Modeling and Hf-W Chronometry of Iron Meteorites

    Science.gov (United States)

    Neumann, W.; Kruijer, T. S.; Breuer, D.; Kleine, T.

    2018-02-01

    Iron meteorites provide some of the most direct insights into the processes and timescales of core formation in planetesimals. Of these, group IVB irons stand out by having one of the youngest 182Hf-182W model ages for metal segregation (2.9 ± 0.6 Ma after solar system formation), as well as the lowest bulk sulfur content and hence highest liquidus temperature. Here, using a new model for the internal evolution of the IVB parent body, we show that a single stage of metal-silicate separation cannot account for the complete melting of pure Fe metal at the relatively late time given by the Hf-W model age. Instead, a complex metal-silicate separation scenario is required that includes migration of partial silicate melts, formation of a shallow magma ocean, and core formation in two distinct stages of metal segregation. In the first stage, a protocore formed at ≈1.5 Ma via settling of metal particles in a mantle magma ocean, followed by metal segregation from a shallow magma ocean at ≈5.4 Ma. As these stages of metal segregation occurred at different times, the two metal fractions had different 182W compositions. Consequently, the final 182W composition of the IVB core does not correspond to a single differentiation event, but represents the average composition of early- and late-segregated core fractions. Our best fit model indicates an ≈100 km radius for the IVB parent body and provides an accretion age of ≈0.1-0.5 Ma after solar system formation. The computed solidification time is, furthermore, consistent with the Re-Os age for crystallization of the IVB core.

  2. Barriers to implementing evidence-based clinical guidelines: A survey of early adopters

    Science.gov (United States)

    Spallek, Heiko; Song, Mei; Polk, Deborah E; Bekhuis, Tanja; Frantsve-Hawley, Julie; Aravamudhan, Krishna

    2010-01-01

    Objective The purpose of this study is to identify barriers that early-adopting dentists perceive as common and challenging when implementing recommendations from evidence-based (EB) clinical guidelines. Method This is a cross-sectional study. Dentists who attended the 2008 Evidence-based Dentistry Champion Conference were eligible for inclusion. Forty-three dentists (34%) responded to a 22-item questionnaire administered online. Two investigators independently coded and categorized responses to open-ended items. Descriptive statistics were computed to assess the frequency of barriers and perceived challenges. Results The most common barriers to implementation are difficulty in changing current practice model, resistance and criticism from colleagues, and lack of trust in evidence or research. Barriers perceived as serious problems have to do with lack of up-to-date evidence, lack of clear answers to clinical questions, and contradictory information in the scientific literature. Conclusions Knowledge of barriers will help improve translation of biomedical research for dentists. Information in guidelines needs to be current, clear, and simplified for use at chairside; dentists’ fears need to be addressed. PMID:21093800

  3. Evidence for early irrigation at Bat (Wadi Sharsah, northwestern Oman) before the advent of farming villages

    Science.gov (United States)

    Desruelles, Stéphane; Fouache, Eric; Eddargach, Wassel; Cammas, Cecilia; Wattez, Julia; Beuzen-Waller, Tara; Martin, Chloé; Tengberg, Margareta; Cable, Charlotte; Thornton, Christopher; Murray, Andrew

    2016-10-01

    Decades of archaeological research in southeastern Arabia (Oman and the UAE) have provided a good understanding of the evolution of human societies in this arid region, with the transition from mobile pastoralism to settled agricultural villages occurring at the start of the Hafit period (ca. 3100-2700 BCE). The delayed adoption of farming, ceramics, mudbrick architecture, metallurgy, and other technologies until the start of the 3rd millennium BCE has been a particularly salient feature of this region relative to its neighbours in Mesopotamia, southern Iran, and northwestern South Asia. However, recent geoarchaeological research at the World Heritage Site of Bat, situated within the Wadi Sharsah valley in northwest Oman, has provided evidence of irrigation practices that have been dated to the early-mid 4th millennium BCE. While direct evidence of farming from this early period remains elusive, the presence of irrigated fields at this time raises new questions about the supposedly mobile pastoralist groups of the Arabian Neolithic and the beginning of farming practices in the region.

  4. Pacopampa: Early evidence of violence at a ceremonial site in the northern Peruvian highlands.

    Science.gov (United States)

    Nagaoka, Tomohito; Uzawa, Kazuhiro; Seki, Yuji; Morales Chocano, Daniel

    2017-01-01

    Pacopampa, a ceremonial complex in Peru's northern highlands, reveals early evidence of trauma in the Middle to Late Formative Period coinciding with the emergence of social stratification in the area. We examine the prevalence of trauma in human remains found at the site and present evidence of the circumstances surrounding the deaths of individuals who lived during the early stages of Andean civilization. The materials are the remains of 104 individuals (38 non-adult and 66 adult) from the Middle to Late Formative Periods. We explored trauma macroscopically and recorded patterns based on skeletons' locations, age at death, sex, social class, and chronology. We detected trauma in remains over the Middle to Late Formative Periods. While the prevalence of trauma was minimal in the Middle Formative Period, skeletons from the subsequent era exhibit more severe disturbances. However, all the skeletons show signs of healing and affected individuals experienced a low degree of trauma. Given the archaeological context (the remains were recovered from sites of ceremonial practices), as well as the equal distribution of trauma among both sexes and a lack of defensive architecture, it is plausible that rituals, rather than organized warfare or raids, caused most of the exhibited trauma. Pacopampa was home to a complex society founded on ritual activity in a ceremonial center: this is indicated by the presence of ritual violence in a society that built impressively large, ceremonial architecture and developed social stratification without any political control of surplus agricultural goods.

  5. Aural exostoses (surfer's ear) provide vital fossil evidence of an aquatic phase in Man's early evolution.

    Science.gov (United States)

    Rhys Evans, P H; Cameron, M

    2017-11-01

    For over a century, otolaryngologists have recognised the condition of aural exostoses, but their significance and aetiology remains obscure, although they tend to be associated with frequent swimming and cold water immersion of the auditory canal. The fact that this condition is usually bilateral is predictable since both ears are immersed in water. However, why do exostoses only grow in swimmers and why do they grow in the deep bony meatus at two or three constant sites? Furthermore, from an evolutionary point of view, what is or was the purpose and function of these rather incongruous protrusions? In recent decades, paleoanthropological evidence has challenged ideas about early hominid evolution. In 1992 the senior author suggested that aural exostoses were evolved in early hominid Man for protection of the delicate tympanic membrane during swimming and diving by narrowing the ear canal in a similar fashion to other semiaquatic species. We now provide evidence for this theory and propose an aetiological explanation for the formation of exostoses.

  6. PLANET-PLANET SCATTERING IN PLANETESIMAL DISKS. II. PREDICTIONS FOR OUTER EXTRASOLAR PLANETARY SYSTEMS

    International Nuclear Information System (INIS)

    Raymond, Sean N.; Armitage, Philip J.; Gorelick, Noel

    2010-01-01

    We develop an idealized dynamical model to predict the typical properties of outer extrasolar planetary systems, at radii comparable to the Jupiter-to-Neptune region of the solar system. The model is based upon the hypothesis that dynamical evolution in outer planetary systems is controlled by a combination of planet-planet scattering and planetary interactions with an exterior disk of small bodies ('planetesimals'). Our results are based on 5000 long duration N-body simulations that follow the evolution of three planets from a few to 10 AU, together with a planetesimal disk containing 50 M + from 10 to 20 AU. For large planet masses (M ∼> M Sat ), the model recovers the observed eccentricity distribution of extrasolar planets. For lower-mass planets, the range of outcomes in models with disks is far greater than that which is seen in isolated planet-planet scattering. Common outcomes include strong scattering among massive planets, sudden jumps in eccentricity due to resonance crossings driven by divergent migration, and re-circularization of scattered low-mass planets in the outer disk. We present the distributions of the eccentricity and inclination that result, and discuss how they vary with planet mass and initial system architecture. In agreement with other studies, we find that the currently observed eccentricity distribution (derived primarily from planets at a ∼ -1 and periods in excess of 10 years will provide constraints on this regime. Finally, we present an analysis of the predicted separation of planets in two-planet systems, and of the population of planets in mean-motion resonances (MMRs). We show that, if there are systems with ∼ Jupiter-mass planets that avoid close encounters, the planetesimal disk acts as a damping mechanism and populates MMRs at a very high rate (50%-80%). In many cases, resonant chains (in particular the 4:2:1 Laplace resonance) are set up among all three planets. We expect such resonant chains to be common among massive

  7. Early Childhood Education, Child Development and School Readiness: Evidence from Zambia

    Directory of Open Access Journals (Sweden)

    Stephanie Simmons Zuilkowski

    2012-12-01

    Full Text Available While early childhood education has received increasing attention in the developing world in recent years, relatively little evidence is available from sub-Saharan Africa on its effects on child development and subsequent school enrolment. We use a prospective case-control design to evaluate the developmental impact of a community-based early childhood center in an urban area in Zambia. Comparing 40 children attending the center to 40 children not attending the center from the same community, we find that center attendance was associated with significantly better performance in an assessment of task orientation, and was also weakly associated with increased letter familiarity. We also observed higher performance among center students on tests of receptive language and pencil-related fine motor skills. These associations were, however, smaller and not statistically significant. We conducted a follow-up one year after the initial assessment, when children were seven years old and should have been in first grade. At follow-up, 27% of non-attendees were not yet enrolled in primary school, compared to just 11% of center students, suggesting that participation in early education encourages a timely transition into first grade.

  8. Watch out! Magnetoencephalographic evidence for early modulation of attention orienting by fearful gaze cueing.

    Directory of Open Access Journals (Sweden)

    Fanny Lachat

    Full Text Available Others' gaze and emotional facial expression are important cues for the process of attention orienting. Here, we investigated with magnetoencephalography (MEG whether the combination of averted gaze and fearful expression may elicit a selectively early effect of attention orienting on the brain responses to targets. We used the direction of gaze of centrally presented fearful and happy faces as the spatial attention orienting cue in a Posner-like paradigm where the subjects had to detect a target checkerboard presented at gazed-at (valid trials or non gazed-at (invalid trials locations of the screen. We showed that the combination of averted gaze and fearful expression resulted in a very early attention orienting effect in the form of additional parietal activity between 55 and 70 ms for the valid versus invalid targets following fearful gaze cues. No such effect was obtained for the targets following happy gaze cues. This early cue-target validity effect selective of fearful gaze cues involved the left superior parietal region and the left lateral middle occipital region. These findings provide the first evidence for an effect of attention orienting induced by fearful gaze in the time range of C1. In doing so, they demonstrate the selective impact of combined gaze and fearful expression cues in the process of attention orienting.

  9. Scoping the evidence for EarlyBird and EarlyBird Plus, two United Kingdom-developed parent education training programmes for autism spectrum disorder.

    Science.gov (United States)

    Dawson-Squibb, John-Joe; Davids, Eugene Lee; de Vries, Petrus J

    2018-03-01

    EarlyBird and EarlyBird Plus are parent education and training programmes designed by the UK National Autistic Society in 1997 and 2003, having been delivered to more than 27,000 families in 14 countries. These group-based programmes aim to (1) support parents immediately after diagnosis of autism spectrum disorder, (2) empower parents, encouraging a positive perception of their child's autism spectrum disorder and (3) help parents establish good practice. In the absence of any previous comprehensive review, we performed a scoping review of all peer-reviewed publications on EarlyBird/EarlyBird Plus. A search was conducted between February and June 2016 using EbscoHost, Sabinet, SAGE Journals, Directory of Open Access Journals, BioMed Central, Scopus, ScienceDirect and grey literature. Two reviewers independently screened titles and abstracts for inclusion. In total, 18 articles were identified: 16 from the United Kingdom and 2 from New Zealand. We reviewed the context, study populations, design, outcome measures, whether focus was on parental perception, parental change or child changes and programme feasibility. Strong parental support for the acceptability but lower level evidence of efficacy of EarlyBird/EarlyBird Plus was found. Future research should consider randomised controlled trials. There is no research on EarlyBird/EarlyBird Plus in low-resource settings; therefore, we recommend broader feasibility evaluation of EarlyBird/EarlyBird Plus including accessibility, cultural appropriateness and scalability.

  10. SMACK: A New Algorithm for Modeling Collisions and Dynamics of Planetesimals in Debris Disks

    Science.gov (United States)

    Nesvold, Erika Rose; Kuchner, Marc J.; Rein, Hanno; Pan, Margaret

    2013-01-01

    We present the Superparticle Model/Algorithm for Collisions in Kuiper belts and debris disks (SMACK), a new method for simultaneously modeling, in 3-D, the collisional and dynamical evolution of planetesimals in a debris disk with planets. SMACK can simulate azimuthal asymmetries and how these asymmetries evolve over time. We show that SMACK is stable to numerical viscosity and numerical heating over 10(exp 7) yr, and that it can reproduce analytic models of disk evolution. We use SMACK to model the evolution of a debris ring containing a planet on an eccentric orbit. Differential precession creates a spiral structure as the ring evolves, but collisions subsequently break up the spiral, leaving a narrower eccentric ring.

  11. Synthesis of Amino Acid Precursors with Organic Solids in Planetesimals with Liquid Water

    Science.gov (United States)

    Kebukawa, Y; Misawa, S.; Matsukuma, J.; Chan, Q. H. S.; Kobayashi, J.; Tachibana, S.; Zolensky, M. E.

    2017-01-01

    Amino acids are important ingredients of life that would have been delivered to Earth by extraterrestrial sources, e.g., comets and meteorites. Amino acids are found in aqueously altered carbonaceous chondrites in good part in the form of precursors that release amino acids after acid hydrolysis. Meanwhile, most of the organic carbon (greater than 70 weight %) in carbonaceous chondrites exists in the form of solvent insoluble organic matter (IOM) with complex macromolecular structures. Complex macromolecular organic matter can be produced by either photolysis of interstellar ices or aqueous chemistry in planetesimals. We focused on the synthesis of amino acids during aqueous alteration, and demonstrated one-pot synthesis of a complex suite of amino acids simultaneously with IOM via hydrothermal experiments simulating the aqueous processing

  12. THE ROLE OF PEBBLE FRAGMENTATION IN PLANETESIMAL FORMATION. I. EXPERIMENTAL STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Syed, M. Bukhari; Blum, J. [Institut für Geophysik und extraterrestrische Physik, Technische Universität zu Braunschweig, Mendelssohnstr. 3, D-38106 Braunschweig (Germany); Jansson, K. Wahlberg; Johansen, A. [Lund Observatory, Department of Astronomy and Theoretical Physics, Lund University, Box 43, SE-221 00 Lund (Sweden)

    2017-01-10

    Previous work on protoplanetary dust growth shows a halt at centimeter sizes owing to the occurrence of bouncing at velocities of ≳0.1 m s{sup −1} and fragmentation at velocities ≳1 m s{sup −1}. To overcome these barriers, spatial concentration of centimeter-sized dust pebbles and subsequent gravitational collapse have been proposed. However, numerical investigations have shown that dust aggregates may undergo fragmentation during the gravitational collapse phase. This fragmentation in turn changes the size distribution of the solids and thus must be taken into account in order to understand the properties of the planetesimals that form. To explore the fate of dust pebbles undergoing fragmenting collisions, we conducted laboratory experiments on dust-aggregate collisions with a focus on establishing a collision model for this stage of planetesimal formation. In our experiments, we analyzed collisions of dust aggregates with masses between 0.7 and 91 g mass ratios between target and projectile from 1 to 126 at a fixed porosity of 65%, within the velocity range of 1.5–8.7 m s{sup −1}, at low atmospheric pressure of ∼10{sup −3} mbar, and in free-fall conditions. We derived the mass of the largest fragment, the fragment size/mass distribution, and the efficiency of mass transfer as a function of collision velocity and projectile/target aggregate size. Moreover, we give recipes for an easy-to-use fragmentation and mass-transfer model for further use in modeling work. In a companion paper, we use the experimental findings and the derived dust-aggregate collision model to investigate the fate of dust pebbles during gravitational collapse.

  13. Early evidence (ca. 12,000 B.P.) for feasting at a burial cave in Israel

    OpenAIRE

    Munro, Natalie D.; Grosman, Leore

    2010-01-01

    Feasting is one of humanity's most universal and unique social behaviors. Although evidence for feasting is common in the early agricultural societies of the Neolithic, evidence in pre-Neolithic contexts is more elusive. We found clear evidence for feasting on wild cattle and tortoises at Hilazon Tachtit cave, a Late Epipaleolithic (12,000 calibrated years B.P.) burial site in Israel. This includes unusually high densities of butchered tortoise and wild cattle remains in two structures, the u...

  14. Investigation of Maternal-Infant Attachment In The Early Postpartum Period With Evidence Based Practice

    Directory of Open Access Journals (Sweden)

    Asli Gulesen

    2013-04-01

    Full Text Available Healthy attachment is a key concept in creating a positive environment for the development of the infant after birth. The earlier and the healthier the mother creates a communication and interaction with her baby, a stronger maternal-infant attachment will be developed. The time period immediately after birth is the most convenient time for the initiation of positive mother-infant relationship as it is the most intense period of attachment. The aim of this article was to define mother-infant attachment and to examine the evidence-based practices for midwives and nurses who play a role in the development of this attachment in the early postpartum period. [TAF Prev Med Bull 2013; 12(2.000: 177-182

  15. Hip Dislocation and Dystocia in Early Medieval Times: Possible Evidence of Labor Maneuver.

    Science.gov (United States)

    Malgosa, Assumpció; Carrascal, Susana; Piga, Giampaolo; Isidro, Albert

    2016-12-01

    In ancient times, maternal mortality would occur frequently, particularly during labor. Evidence of dystocia resulting in the death of a pregnant woman is very infrequent in paleopathologic literature, with only a few cases being demonstrated. In the early medieval site of Casserres, the skeleton of a young woman with a fetus in the pelvic region was found. Some abnormal findings of the maternal skeleton were evaluated, including a sacral anomaly, femoral head wound, the rare position of the lower left limb with the femoral head dislodged anteriorly and cephalad from the socket, and a fibular fracture. Examining the anomalies all together, a case of anterior hip dislocation related to a McRoberts-like maneuver performed during labor is a plausible explanation of the findings.

  16. Early-life conditions and child development: Evidence from a violent conflict.

    Science.gov (United States)

    Duque, Valentina

    2017-12-01

    This paper investigates how the exposure to violent conflicts in utero and in early and late childhood affect human capital formation. I focus on a wide range of child development outcomes, including novel cognitive and non-cognitive indicators. Using monthly and municipality-level variation in the timing and severity of massacres in Colombia from 1999 to 2007, I show that children exposed to terrorist attacks in utero and in childhood achieve lower height-for-age (0.09 SD) and cognitive outcomes (PPVT falls by 0.18SD and math reasoning and general knowledge fall by 0.16SD), and that these results are robust to controlling for mother fixed-effects. The timing of these exposures matters and differs by type of skill. In terms of parental investments, I find some evidence that parents reinforce the negative effects of violence by increasing their frequency of physical aggression.

  17. Early-life conditions and child development: Evidence from a violent conflict

    Directory of Open Access Journals (Sweden)

    Valentina Duque

    2017-12-01

    Full Text Available This paper investigates how the exposure to violent conflicts in utero and in early and late childhood affect human capital formation. I focus on a wide range of child development outcomes, including novel cognitive and non-cognitive indicators. Using monthly and municipality-level variation in the timing and severity of massacres in Colombia from 1999 to 2007, I show that children exposed to terrorist attacks in utero and in childhood achieve lower height-for-age (0.09 SD and cognitive outcomes (PPVT falls by 0.18SD and math reasoning and general knowledge fall by 0.16SD, and that these results are robust to controlling for mother fixed-effects. The timing of these exposures matters and differs by type of skill. In terms of parental investments, I find some evidence that parents reinforce the negative effects of violence by increasing their frequency of physical aggression.

  18. Neglected evidence in idiopathic pulmonary fibrosis and the importance of early diagnosis and treatment.

    Science.gov (United States)

    Cottin, Vincent; Richeldi, Luca

    2014-03-01

    In idiopathic pulmonary fibrosis (IPF), some facts or concepts based on substantial evidence, whilst implicit for learned subspecialists, have previously been neglected and/or not explicitly formulated or made accessible to a wider audience. IPF is strongly associated with cigarette smoking and is predominantly a disease of ageing. However, its cause(s) remain elusive and, thus, it is one of the most challenging diseases for the development of novel effective and safe therapies. With the approval of pirfenidone for patients with mild-to-moderate IPF, an earlier diagnosis of IPF is a prerequisite for earlier treatment and, potentially, improvement of the long-term clinical outcome of this progressive and ultimately fatal disease. An earlier diagnosis may be achieved in IPF by promoting thin-slice chest high-resolution computed tomography screening of interstitial lung disease as a "by-product" of large-scale lung cancer screening strategies in smokers, but other techniques, which have been neglected in the past, are now available. Lung auscultation and early identification of "velcro" crackles has been proposed as a key component of early diagnosis of IPF. An ongoing study is exploring correlations between lung sounds on auscultation obtained using electronic stethoscopes and high-resolution computed tomography patterns.

  19. Early and parallel processing of pragmatic and semantic information in speech acts: neurophysiological evidence

    Directory of Open Access Journals (Sweden)

    Natalia eEgorova

    2013-03-01

    Full Text Available Although language is a tool for communication, most research in the neuroscience of language has focused on studying words and sentences, while little is known about the brain mechanisms of speech acts, or communicative functions, for which words and sentences are used as tools. Here the neural processing of two types of speech acts, Naming and Requesting, was addressed using the time-resolved event-related potential (ERP technique. The brain responses for Naming and Request diverged as early as ~120 ms after the onset of the critical words, at the same time as, or even before, the earliest brain manifestations of semantic word properties could be detected. Request-evoked potentials were generally larger in amplitude than those for Naming. The use of identical words in closely matched settings for both speech acts rules out explanation of the difference in terms of phonological, lexical, semantic properties or word expectancy. The cortical sources underlying the ERP enhancement for Requests were found in the fronto-central cortex, consistent with the activation of action knowledge, as well as in right temporo-parietal junction, possibly reflecting additional implications of speech acts for social interaction and theory of mind. These results provide the first evidence for surprisingly early access to pragmatic and social interactive knowledge, which possibly occurs in parallel with other types of linguistic processing, and thus supports the near-simultaneous access to different subtypes of psycholinguistic information.

  20. Genetic evidence for the association between the early growth response 3 (EGR3 gene and schizophrenia.

    Directory of Open Access Journals (Sweden)

    Rui Zhang

    Full Text Available Recently, two genome scan meta-analysis studies have found strong evidence for the association of loci on chromosome 8p with schizophrenia. The early growth response 3 (EGR3 gene located in chromosome 8p21.3 was also found to be involved in the etiology of schizophrenia. However, subsequent studies failed to replicate this finding. To investigate the genetic role of EGR3 in Chinese patients, we genotyped four SNPs (average interval ∼2.3 kb in the chromosome region of EGR3 in 470 Chinese schizophrenia patients and 480 healthy control subjects. The SNP rs35201266 (located in intron 1 of EGR3 showed significant differences between cases and controls in both genotype frequency distribution (P = 0.016 and allele frequency distribution (P = 0.009. Analysis of the haplotype rs35201266-rs3750192 provided significant evidence for association with schizophrenia (P = 0.0012; a significant difference was found for the common haplotype AG (P = 0.0005. Furthermore, significant associations were also found in several other two-, and three-SNP tests of haplotype analyses. The meta-analysis revealed a statistically significant association between rs35201266 and schizophrenia (P = 0.0001. In summary, our study supports the association of EGR3 with schizophrenia in our Han Chinese sample, and further functional exploration of the EGR3 gene will contribute to the molecular basis for the complex network underlying schizophrenia pathogenesis.

  1. Implementing three evidence-based program models: early lessons from the Teen Pregnancy Prevention Replication Study.

    Science.gov (United States)

    Kelsey, Meredith; Layzer, Jean

    2014-03-01

    This article describes some of the early implementation challenges faced by nine grantees participating in the Teen Pregnancy Prevention Replication Study and their response to them. The article draws on information collected as part of a comprehensive implementation study. Sources include site and program documents; program officer reports; notes from site investigation, selection and negotiation; ongoing communications with grantees as part of putting the study into place; and semi-structured interviews with program staff. The issues faced by grantees in implementing evidence-based programs designed to prevent teen pregnancy varied by program model. Grantees implementing a classroom-based curriculum faced challenges in delivering the curriculum within the constraints of school schedules and calendars (program length and size of class). Grantees implementing a culturally tailored curriculum faced a series of challenges, including implementing the intervention as part of the regular school curriculum in schools with diverse populations; low attendance when delivered as an after-school program; and resistance on the part of schools to specific curriculum content. The third set of grantees, implementing a program in clinics, faced challenges in identifying and recruiting young women into the program and in retaining young women once they were in the program. The experiences of these grantees reflect some of the complexities that should be carefully considered when choosing to replicate evidence-based programs. The Teen Pregnancy Prevention replication study will provide important context for assessing the effectiveness of some of the more widely replicated evidence-based programs. Copyright © 2014 Society for Adolescent Health and Medicine. All rights reserved.

  2. Origin and Evolution of The Early- Silurian Land Vascular Plants: Evidence From Biomarkers

    Science.gov (United States)

    Jin, R.

    2016-12-01

    Origin and early evolution of land vascular plants, is one of the most intriguing hotspots in the life science research. During the 1970s and 1980s,Pinnatiramosus qianensis was found in early-Silurian strata in guizhou of south China.43 years have passed. But so far, the biological characteristics and belonging of the age of this unique plant have been debated again and again, up in the air.Biomarkers have a good stability in the process of organic evolution, no more or less changed, so they have a special `function of mark'. While biomarkers can provide information about organic matter of hydrocarbon source rock (the source), the period of deposition and burial (diagenesis) environmental conditions, and many other aspects of information.This paper obtained the sedimentary environment, source of organic matter input and other relevant information, through extracting and analyzing biomarkers of the 26 samples in the late Ordovician to early Silurian strata in NorthGuizhou areas. According to the results, Pr/Ph of late Ordovician Meitan Fm-early Silurian Hanjiadian Fm is high.It manifests more pristane, characterized by reductive environment. At the bottom of the Hanjiadian Fm, Pr/Ph has a volatility.Some huge environmental changes may have taken place in the corresponding period. N-alkanes do not have parity advantage or has even carbon advantage slightly.The peak carbon is mainly in low carbon number.(C21 + C22)/(C28 + C29) is high.Aquatic organisms is a major source of organic matter during this period,C21-/C22+ is low.This may be caused by the relatively serious loss of light hydrocarbon during the separation of components. In the Hanjiadian Fm,information of C29/C27 sterane ratios and oleanane index showed a trend of rising at the same time, indicating that during this period, there was a gradual increase input in the number of higher plants.The stable carbon isotope of saturated hydrocarbon and aromatic hydrocarbon in the Hanjiadian Fm also gradually become

  3. Early Start Denver Model. Un modello Evidence Based per l’intervento educativo precoce nei Disturbi dello Spettro Autistico

    OpenAIRE

    Saverio Fontani

    2016-01-01

    The Autism Spectrum Disorders represents one of the most complex developmental disabilities for the massive deficit of communication competences. The social disability related to disorders is the main objective of the intervention of the Early Start Denver Model – ESDM (Rogers & Dawson, 2010), which can be considered as one of the most advanced models for early educational intervention according the perspective of Evidence Based Education. In this paper the theoretical foundations of the ...

  4. Azimuthal asymmetries in the debris disk around HD 61005. A massive collision of planetesimals?

    Science.gov (United States)

    Olofsson, J.; Samland, M.; Avenhaus, H.; Caceres, C.; Henning, Th.; Moór, A.; Milli, J.; Canovas, H.; Quanz, S. P.; Schreiber, M. R.; Augereau, J.-C.; Bayo, A.; Bazzon, A.; Beuzit, J.-L.; Boccaletti, A.; Buenzli, E.; Casassus, S.; Chauvin, G.; Dominik, C.; Desidera, S.; Feldt, M.; Gratton, R.; Janson, M.; Lagrange, A.-M.; Langlois, M.; Lannier, J.; Maire, A.-L.; Mesa, D.; Pinte, C.; Rouan, D.; Salter, G.; Thalmann, C.; Vigan, A.

    2016-06-01

    Context. Debris disks offer valuable insights into the latest stages of circumstellar disk evolution, and can possibly help us to trace the outcomes of planetary formation processes. In the age range 10 to 100 Myr, most of the gas is expected to have been removed from the system, giant planets (if any) must have already been formed, and the formation of terrestrial planets may be on-going. Pluto-sized planetesimals, and their debris released in a collisional cascade, are under their mutual gravitational influence, which may result into non-axisymmetric structures in the debris disk. Aims: High angular resolution observations are required to investigate these effects and constrain the dynamical evolution of debris disks. Furthermore, multi-wavelength observations can provide information about the dust dynamics by probing different grain sizes. Methods: Here we present new VLT/SPHERE and ALMA observations of the debris disk around the 40 Myr-old solar-type star HD 61005. We resolve the disk at unprecedented resolution both in the near-infrared (in scattered and polarized light) and at millimeter wavelengths. We perform a detailed modeling of these observations, including the spectral energy distribution. Results: Thanks to the new observations, we propose a solution for both the radial and azimuthal distribution of the dust grains in the debris disk. We find that the disk has a moderate eccentricity (e ~ 0.1) and that the dust density is two times larger at the pericenter compared to the apocenter. Conclusions: With no giant planets detected in our observations, we investigate alternative explanations besides planet-disk interactions to interpret the inferred disk morphology. We postulate that the morphology of the disk could be the consequence of a massive collision between ~1000 km-sized bodies at ~61 au. If this interpretation holds, it would put stringent constraints on the formation of massive planetesimals at large distances from the star. Based on observations

  5. The Dynamics and Implications of Gap Clearing via Planets in Planetesimal (Debris) Disks

    Science.gov (United States)

    Morrison, Sarah Jane

    Exoplanets and debris disks are examples of solar systems other than our own. As the dusty reservoirs of colliding planetesimals, debris disks provide indicators of planetary system evolution on orbital distance scales beyond those probed by the most prolific exoplanet detection methods, and on timescales 10 r to 10 Gyr. The Solar System possesses both planets and small bodies, and through studying the gravitational interactions between both, we gain insight into the Solar System's past. As we enter the era of resolved observations of debris disks residing around other stars, I add to our theoretical understanding of the dynamical interactions between debris, planets, and combinations thereof. I quantify how single planets clear material in their vicinity and how long this process takes for the entire planetary mass regime. I use these relationships to assess the lowest mass planet that could clear a gap in observed debris disks over the system's lifetime. In the distant outer reaches of gaps in young debris systems, this minimum planet mass can exceed Neptune's. To complement the discoveries of wide-orbit, massive, exoplanets by direct imaging surveys, I assess the dynamical stability of high mass multi-planet systems to estimate how many high mass planets could be packed into young, gapped debris disks. I compare these expectations to the planet detection rates of direct imaging surveys and find that high mass planets are not the primary culprits for forming gaps in young debris disk systems. As an alternative model for forming gaps in planetesimal disks with planets, I assess the efficacy of creating gaps with divergently migrating pairs of planets. I find that migrating planets could produce observed gaps and elude detection. Moreover, the inferred planet masses when neglecting migration for such gaps could be expected to be observable by direct imaging surveys for young, nearby systems. Wide gaps in young systems would likely still require more than two

  6. The earliest evidence for a supraorbital salt gland in dinosaurs in new Early Cretaceous ornithurines.

    Science.gov (United States)

    Wang, Xia; Huang, Jiandong; Hu, Yuanchao; Liu, Xiaoyu; Peteya, Jennifer; Clarke, Julia A

    2018-03-05

    Supraorbital fossae occur when salt glands are well developed, a condition most pronounced in marine and desert-dwelling taxa in which salt regulation is key. Here, we report the first specimens from lacustrine environments of the Jehol Biota that preserve a distinct fossa above the orbit, where the salt gland fossa is positioned in living birds. The Early Cretaceous ornithurine bird specimens reported here are about 40 million years older than previously reported Late Cretaceous marine birds and represent the earliest described occurrence of the fossa. We find no evidence of avian salt gland fossae in phylogenetically earlier stem birds or non-avialan dinosaurs, even in those argued to be predominantly marine or desert dwelling. The apparent absence of this feature in more basal dinosaurs may indicate that it is only after miniaturization close to the origin of flight that excretory mechanisms were favored over exclusively renal mechanisms of salt regulation resulting in an increase in gland size leaving a bony trace. The ecology of ornithurine birds is more diverse than in other stem birds and may have included seasonal shifts in foraging range, or, the environments of some of the Jehol lakes may have included more pronounced periods of high salinity.

  7. Ab interno trabeculectomy: ultrastructural evidence and early tissue response in a human eye.

    Science.gov (United States)

    Ferrari, Ettore; Ortolani, Fulvia; Petrelli, Lucia; Contin, Magali; Pognuz, Derri Roman; Marchini, Maurizio; Bandello, Francesco

    2007-10-01

    To report the results of ultrastructural analysis of the postoperative effects of ab interno trabeculectomy in a human eye. Department of Ophthalmology, Palmanova Hospital, Palmanova, Udine, Italy. A 60-year-old woman with cataract and glaucoma had enucleation for a choroidal melanoma 10 days after ab interno trabeculectomy combined with phacoemulsification. A second ab interno trabeculectomy was performed after enucleation to evaluate the outcomes of the previous trabeculectomy. Light and transmission electron microscopy analyses were performed on samples excised from areas (1) not subjected to a procedure (control samples), (2) that had ab interno trabeculectomy before enucleation, and (3) that had ab interno trabeculectomy immediately after enucleation. Control samples showed normal trabecular features. Semithin sections of all ab interno trabeculectomy samples showed full-thickness removal of trabeculum segments, with Schlemm's canal lumen opening into the anterior chamber and apparent preservation of the adjacent structures. On ultrathin sections of samples that had ab interno trabeculectomy before enucleation, the endothelium lining the outer wall of Schlemm's canal and other angle components showed intact ultrastructural features. In trabecular beams that were not removed, the extracellular matrix appeared to have maintained its fine texture and was free of activated fibroblasts or leucocyte infiltrates. Observations confirm that ab interno trabeculectomy causes direct communication between Schlemm's canal lumen and the anterior chamber in vivo and immediately after enucleation during the early postoperative period. The absence of an evident inflammatory reaction in the examined case should be considered with caution because of possible tumor-induced immune suppression.

  8. Early modern human dispersal from Africa: genomic evidence for multiple waves of migration.

    Science.gov (United States)

    Tassi, Francesca; Ghirotto, Silvia; Mezzavilla, Massimo; Vilaça, Sibelle Torres; De Santi, Lisa; Barbujani, Guido

    2015-01-01

    Anthropological and genetic data agree in indicating the African continent as the main place of origin for anatomically modern humans. However, it is unclear whether early modern humans left Africa through a single, major process, dispersing simultaneously over Asia and Europe, or in two main waves, first through the Arab Peninsula into southern Asia and Oceania, and later through a northern route crossing the Levant. Here, we show that accurate genomic estimates of the divergence times between European and African populations are more recent than those between Australo-Melanesia and Africa and incompatible with the effects of a single dispersal. This difference cannot possibly be accounted for by the effects of either hybridization with archaic human forms in Australo-Melanesia or back migration from Europe into Africa. Furthermore, in several populations of Asia we found evidence for relatively recent genetic admixture events, which could have obscured the signatures of the earliest processes. We conclude that the hypothesis of a single major human dispersal from Africa appears hardly compatible with the observed historical and geographical patterns of genome diversity and that Australo-Melanesian populations seem still to retain a genomic signature of a more ancient divergence from Africa.

  9. Behavioral and electrophysiological evidence for early and automatic detection of phonological equivalence in variable speech inputs.

    Science.gov (United States)

    Kharlamov, Viktor; Campbell, Kenneth; Kazanina, Nina

    2011-11-01

    Speech sounds are not always perceived in accordance with their acoustic-phonetic content. For example, an early and automatic process of perceptual repair, which ensures conformity of speech inputs to the listener's native language phonology, applies to individual input segments that do not exist in the native inventory or to sound sequences that are illicit according to the native phonotactic restrictions on sound co-occurrences. The present study with Russian and Canadian English speakers shows that listeners may perceive phonetically distinct and licit sound sequences as equivalent when the native language system provides robust evidence for mapping multiple phonetic forms onto a single phonological representation. In Russian, due to an optional but productive t-deletion process that affects /stn/ clusters, the surface forms [sn] and [stn] may be phonologically equivalent and map to a single phonological form /stn/. In contrast, [sn] and [stn] clusters are usually phonologically distinct in (Canadian) English. Behavioral data from identification and discrimination tasks indicated that [sn] and [stn] clusters were more confusable for Russian than for English speakers. The EEG experiment employed an oddball paradigm with nonwords [asna] and [astna] used as the standard and deviant stimuli. A reliable mismatch negativity response was elicited approximately 100 msec postchange in the English group but not in the Russian group. These findings point to a perceptual repair mechanism that is engaged automatically at a prelexical level to ensure immediate encoding of speech inputs in phonological terms, which in turn enables efficient access to the meaning of a spoken utterance.

  10. The role of early life environmental risk factors in Parkinson disease: what is the evidence?

    Science.gov (United States)

    Logroscino, Giancarlo

    2005-09-01

    Parkinson disease (PD) is of unknown but presumably multifactorial etiology. Neuropathologic studies and animal models show that exposure to environmental neurotoxicants can determine progressive damage in the substantia nigra many years before the onset of clinical parkinsonism. Therefore, PD, like other neurologic diseases related to aging, may be determined by exposures present in the environment early during the life span or even during pregnancy. Recent epidemiologic studies have focused on the possible role of environmental risk factors present during adult life or aging. Smoking and coffee drinking have consistently been identified to have protective associations, whereas roles of other risk factors such as pesticide and infections have been reported in some studies but not replicated in others. Both genetic inheritance and sharing of common environment in the same family explain the increased risk of PD of relatives of PD cases compared with relatives of controls in familial aggregation studies. Much evidence indicates that risk factors that have a long latency or a slow effect could be important for late-onset PD. Further epidemiologic studies are warranted in this area.

  11. Evident?

    DEFF Research Database (Denmark)

    Plant, Peter

    2012-01-01

    Quality assurance and evidence in career guidance in Europe are often seen as self-evident approaches, but particular interests lie behind......Quality assurance and evidence in career guidance in Europe are often seen as self-evident approaches, but particular interests lie behind...

  12. PLANETESIMAL AND PROTOPLANET DYNAMICS IN A TURBULENT PROTOPLANETARY DISK: IDEAL STRATIFIED DISKS

    International Nuclear Information System (INIS)

    Yang, Chao-Chin; Mac Low, Mordecai-Mark; Menou, Kristen

    2012-01-01

    Due to the gravitational influence of density fluctuations driven by magneto-rotational instability in the gas disk, planetesimals and protoplanets undergo diffusive radial migration as well as changes in other orbital properties. The magnitude of the effect on particle orbits can have important consequences for planet formation scenarios. We use the local-shearing-box approximation to simulate an ideal, isothermal, magnetized gas disk with vertical density stratification and simultaneously evolve numerous massless particles moving under the gravitational field of the gas and the host star. We measure the evolution of the particle orbital properties, including mean radius, eccentricity, inclination, and velocity dispersion, and its dependence on the disk properties and the particle initial conditions. Although the results converge with resolution for fixed box dimensions, we find the response of the particles to the gravity of the turbulent gas correlates with the horizontal box size, up to 16 disk scale heights. This correlation indicates that caution should be exercised when interpreting local-shearing-box models involving gravitational physics of magneto-rotational turbulence. Based on heuristic arguments, nevertheless, the criterion L h /R ∼ O(1), where L h is the horizontal box size and R is the distance to the host star, is proposed to possibly circumvent this conundrum. If this criterion holds, we can still conclude that magneto-rotational turbulence seems likely to be ineffective at driving either diffusive migration or collisional erosion under most circumstances.

  13. GRAVOTURBULENT PLANETESIMAL FORMATION: THE POSITIVE EFFECT OF LONG-LIVED ZONAL FLOWS

    International Nuclear Information System (INIS)

    Dittrich, K.; Klahr, H.; Johansen, A.

    2013-01-01

    Recent numerical simulations have shown long-lived axisymmetric sub- and super-Keplerian flows in protoplanetary disks. These zonal flows are found in local as well as global simulations of disks unstable to the magnetorotational instability. This paper covers our study of the strength and lifetime of zonal flows and the resulting long-lived gas over- and underdensities as functions of the azimuthal and radial size of the local shearing box. We further investigate dust particle concentrations without feedback on the gas and without self-gravity. The strength and lifetime of zonal flows increase with the radial extent of the simulation box, but decrease with the azimuthal box size. Our simulations support earlier results that zonal flows have a natural radial length scale of 5-7 gas pressure scale heights. This is the first study that combines three-dimensional MHD simulations of zonal flows and dust particles feeling the gas pressure. The pressure bumps trap particles with St = 1 very efficiently. We show that St = 0.1 particles (of some centimeters in size if at 5 AU in a minimum mass solar nebula) reach a hundred-fold higher density than initially. This opens the path for particles of St = 0.1 and dust-to-gas ratio of 0.01 or for particles of St ≥ 0.5 and dust-to-gas ratio 10 –4 to still reach densities that potentially trigger the streaming instability and thus gravoturbulent formation of planetesimals.

  14. The Early Development of Human Mirror Mechanisms: Evidence from Electromyographic Recordings at 3 and 6 Months

    Science.gov (United States)

    Turati, Chiara; Natale, Elena; Bolognini, Nadia; Senna, Irene; Picozzi, Marta; Longhi, Elena; Cassia, Viola Macchi

    2013-01-01

    In primates and adult humans direct understanding of others' action is provided by mirror mechanisms matching action observation and action execution (e.g. Casile, Caggiano & Ferrari, 2011). Despite the growing body of evidence detailing the existence of these mechanisms in the adult human brain, their origins and early development are…

  15. Body Size at Birth, Physical Development and Cognitive Outcomes in Early Childhood: Evidence from the Longitudinal Survey of Australian Children

    Science.gov (United States)

    Ulker, Aydogan

    2016-01-01

    Using a rich sample created from the Longitudinal Survey of Australian Children, we investigate the extent to which the relationship between body size at birth and early childhood cognitive skills is mediated by physical development indicators. Consistent with existing evidence from other countries, we find a significant relationship between body…

  16. Investigating CO2 Reservoirs at Gale Crater and Evidence for a Dense Early Atmosphere

    Science.gov (United States)

    Niles, P. B.; Archer, P. D.; Heil, E.; Eigenbrode, J.; McAdam, A.; Sutter, B.; Franz, H.; Navarro-Gonzalez, R.; Ming, D.; Mahaffy, P. R.; hide

    2015-01-01

    One of the most compelling features of the Gale landing site is its age. Based on crater counts, the formation of Gale crater is dated to be near the beginning of the Hesperian near the pivotal Hesperian/Noachian transition. This is a time period on Mars that is linked to increased fluvial activity through valley network formation and also marks a transition from higher erosion rates/clay mineral formation to lower erosion rates with mineralogies dominated by sulfate minerals. Results from the Curiosity mission have shown extensive evidence for fluvial activity within the crater suggesting that sediments on the floor of the crater and even sediments making up Mt. Sharp itself were the result of longstanding activity of liquid water. Warm/wet conditions on early Mars are likely due to a thicker atmosphere and increased abundance of greenhouse gases including the main component of the atmosphere, CO2. Carbon dioxide is minor component of the Earth's atmosphere yet plays a major role in surface water chemistry, weathering, and formation of secondary minerals. An ancient martian atmosphere was likely dominated by CO2 and any waters in equilibrium with this atmosphere would have different chemical characteristics. Studies have noted that high partial pressures of CO2 would result in increased carbonic acid formation and lowering of the pH so that carbonate minerals are not stable. However, if there were a dense CO2 atmosphere present at the Hesperian/Noachian transition, it would have to be stored in a carbon reservoir on the surface or lost to space. The Mt. Sharp sediments are potentially one of the best places on Mars to investigate these CO2 reservoirs as they are proposed to have formed in the early Hesperian, from an alkaline lake, and record the transition to an aeolian dominated regime near the top of the sequence. The total amount of CO2 in the Gale crater soils and sediments is significant but lower than expected if a thick atmosphere was present at the

  17. Embryology of Early Jurassic dinosaur from China with evidence of preserved organic remains.

    Science.gov (United States)

    Reisz, Robert R; Huang, Timothy D; Roberts, Eric M; Peng, ShinRung; Sullivan, Corwin; Stein, Koen; LeBlanc, Aaron R H; Shieh, DarBin; Chang, RongSeng; Chiang, ChengCheng; Yang, Chuanwei; Zhong, Shiming

    2013-04-11

    Fossil dinosaur embryos are surprisingly rare, being almost entirely restricted to Upper Cretaceous strata that record the late stages of non-avian dinosaur evolution. Notable exceptions are the oldest known embryos from the Early Jurassic South African sauropodomorph Massospondylus and Late Jurassic embryos of a theropod from Portugal. The fact that dinosaur embryos are rare and typically enclosed in eggshells limits their availability for tissue and cellular level investigations of development. Consequently, little is known about growth patterns in dinosaur embryos, even though post-hatching ontogeny has been studied in several taxa. Here we report the discovery of an embryonic dinosaur bone bed from the Lower Jurassic of China, the oldest such occurrence in the fossil record. The embryos are similar in geological age to those of Massospondylus and are also assignable to a sauropodomorph dinosaur, probably Lufengosaurus. The preservation of numerous disarticulated skeletal elements and eggshells in this monotaxic bone bed, representing different stages of incubation and therefore derived from different nests, provides opportunities for new investigations of dinosaur embryology in a clade noted for gigantism. For example, comparisons among embryonic femora of different sizes and developmental stages reveal a consistently rapid rate of growth throughout development, possibly indicating that short incubation times were characteristic of sauropodomorphs. In addition, asymmetric radial growth of the femoral shaft and rapid expansion of the fourth trochanter suggest that embryonic muscle activation played an important role in the pre-hatching ontogeny of these dinosaurs. This discovery also provides the oldest evidence of in situ preservation of complex organic remains in a terrestrial vertebrate.

  18. Evidence for an early innate immune response in the motor cortex of ALS.

    Science.gov (United States)

    Jara, Javier H; Genç, Barış; Stanford, Macdonell J; Pytel, Peter; Roos, Raymond P; Weintraub, Sandra; Mesulam, M Marsel; Bigio, Eileen H; Miller, Richard J; Özdinler, P Hande

    2017-06-26

    Recent evidence indicates the importance of innate immunity and neuroinflammation with microgliosis in amyotrophic lateral sclerosis (ALS) pathology. The MCP1 (monocyte chemoattractant protein-1) and CCR2 (CC chemokine receptor 2) signaling system has been strongly associated with the innate immune responses observed in ALS patients, but the motor cortex has not been studied in detail. After revealing the presence of MCP1 and CCR2 in the motor cortex of ALS patients, to elucidate, visualize, and define the timing, location and the extent of immune response in relation to upper motor neuron vulnerability and progressive degeneration in ALS, we developed MCP1-CCR2-hSOD1 G93A mice, an ALS reporter line, in which cells expressing MCP1 and CCR2 are genetically labeled by monomeric red fluorescent protein-1 and enhanced green fluorescent protein, respectively. In the motor cortex of MCP1-CCR2-hSOD1 G93A mice, unlike in the spinal cord, there was an early increase in the numbers of MCP1+ cells, which displayed microglial morphology and selectively expressed microglia markers. Even though fewer CCR2+ cells were present throughout the motor cortex, they were mainly infiltrating monocytes. Interestingly, MCP1+ cells were found in close proximity to the apical dendrites and cell bodies of corticospinal motor neurons (CSMN), further implicating the importance of their cellular interaction to neuronal pathology. Similar findings were observed in the motor cortex of ALS patients, where MCP1+ microglia were especially in close proximity to the degenerating apical dendrites of Betz cells. Our findings reveal that the intricate cellular interplay between immune cells and upper motor neurons observed in the motor cortex of ALS mice is indeed recapitulated in ALS patients. We generated and characterized a novel model system, to study the cellular and molecular basis of this close cellular interaction and how that relates to motor neuron vulnerability and progressive degeneration in

  19. Timing of Early Aptian demise of northern Tethyan carbonate platforms - chemostratigraphic versus biostratigraphic evidence

    Science.gov (United States)

    Huck, Stefan; Immenhauser, Adrian; Heimhofer, Ulrich; Rameil, Niels

    2010-05-01

    A lively controversy still exists between different authors dealing with the timing of northern Tethyan platform drowning and the Early Aptian oceanic anoxic event (OAE 1a). To the present day, there is no consensus if the OAE 1a black shales must be attributed to the Deshayesites weissi or the Deshayesites deshayesi zone (see discussion in Moreno-Bedmar et al., 2009). OAE 1a black shale deposition has been traditionally attributed to the Deshayesites weissi zone (Gradstein et al., 2004). Despite this disagreement about the biostratigraphic timing, several authors postulate a relation between biotic perturbations and environmental changes linked to OAE 1a, e. g. the disappearance of coral-rudist reefs related with the demise of the northern Tethyan Urgonian platforms in the Helvetic Alps (Weissert et al., 1998; Föllmi et al., 2008). In the central and southern Tethyan realm (Istria, Oman), OAE 1a is likely expressed as the transient mass occurrence of microencrusters (Lithocodium-Bacinella) and the coeval demise of the characteristic mid-Cretaceous framework-builders (rudists, corals). Chemostratigraphic data indicate that these microbial blooms coincide with the Deshayesites weissi zone (Huck et al., 2010, Rameil et al, 2010). These observations raise the question whether northern Tethyan platform drowning is coeval to microbial bloom periods in the central and southern Tethys? The analysis of all available literature and unpublished evidence demonstrates that well constrained age data are surprisingly scarce and controversial. The goal of the present research project is to compile a chemostratigraphic framework for the northern Tethyan platform drowning (Haute-Savoie, SE France) in order to shed light on the temporal constraints of platform drowning versus pelagic black shale deposition versus microbial blooms. Two Barremian to Aptian shoalwater sections (Cluses section, Grande Forclaz section) in the Subalpine Chains were investigated applying chemostratigraphy

  20. Early tracheostomy in severe traumatic brain injury: evidence for decreased mechanical ventilation and increased hospital mortality

    Science.gov (United States)

    Dunham, C Michael; Cutrona, Anthony F; Gruber, Brian S; Calderon, Javier E; Ransom, Kenneth J; Flowers, Laurie L

    2014-01-01

    Objective: In the past, the authors performed a comprehensive literature review to identify all randomized controlled trials assessing the impact of early tracheostomy on severe brain injury outcomes. The search produced only two trials, one by Sugerman and another by Bouderka. Subjects and methods: The current authors initiated an Institutional Review Board-approved severe brain injury randomized trial to evaluate the impact of early tracheostomy on ventilator-associated pneumonia rates, intensive care unit (ICU)/ventilator days, and hospital mortality. Current study results were compared with the other randomized trials and a meta-analysis was performed. Results: Early tracheostomy pneumonia rates were Sugerman-48.6%, Bouderka-58.1%, and current study-46.7%. No early tracheostomy pneumonia rates were Sugerman-53.1%, Bouderka-61.3%, and current study-44.4%. Pneumonia rate meta-analysis showed no difference for early tracheostomy and no early tracheostomy (OR 0.89; p = 0.71). Early tracheostomy ICU/ventilator days were Sugerman-16 ± 5.9, Bouderka-14.5 ± 7.3, and current study-14.1 ± 5.7. No early tracheostomy ICU/ventilator days were Sugerman-19 ± 11.3, Bouderka-17.5 ± 10.6, and current study-17 ± 5.4. ICU/ventilator day meta-analysis showed 2.9 fewer days with early tracheostomy (p = 0.02). Early tracheostomy mortality rates were Sugerman-14.3%, Bouderka-38.7%, and current study-0%. No early tracheostomy mortality rates were Sugerman-3.2%, Bouderka-22.6%, and current study-0%. Randomized trial mortality rate meta-analysis showed a higher rate for early tracheostomy (OR 2.68; p = 0.05). Because the randomized trials were small, a literature assessment was undertaken to find all retrospective studies describing the association of early tracheostomy on severe brain injury hospital mortality. The review produced five retrospective studies, with a total of 3,356 patients. Retrospective study mortality rate meta-analysis demonstrated a larger mortality for early

  1. Late Archaic–Early Formative period microbotanical evidence for potato at Jiskairumoko in the Titicaca Basin of southern Peru

    Science.gov (United States)

    Rumold, Claudia Ursula

    2016-01-01

    The data presented in this paper provide direct microbotanical evidence concerning the early use of potato (Solanum tuberosum) within its botanical locus of origin in the high south-central Andes. The data derive from Jiskairumoko, an early village site in the western Titicaca Basin dating to the Late Archaic to Early Formative periods (∼3,400 cal y BC to 1,600 cal y BC). Because the site reflects the transition to sedentism and food production, these data may relate to potato domestication and early cultivation. Of 141 starch microremains recovered from 14 groundstone tools from Jiskairumoko, 50 are identified as consistent with cultivated or domesticated potato, based on reference to published materials and a study of wild and cultivated potato starch morphology. Along with macro- and microbotanical evidence for chenopod consumption and grinding tool data reflecting intensive use of this technology throughout site occupation, the microbotanical data reported here suggest the intensive exploitation, if not cultivation, of plant resources at Jiskairumoko. Elucidating the details of the trajectory of potato domestication is necessary for an overall understanding of the development of highland Andean agriculture, as this crop is central to the autochthonous agricultural suite. A paucity of direct botanical evidence, however, has hindered research efforts. The results of the modern and archaeological starch analyses presented here underscore the utility of this method in addressing questions related to the timing, mode, and context of potato origins. PMID:27849582

  2. Late Archaic-Early Formative period microbotanical evidence for potato at Jiskairumoko in the Titicaca Basin of southern Peru.

    Science.gov (United States)

    Rumold, Claudia Ursula; Aldenderfer, Mark S

    2016-11-29

    The data presented in this paper provide direct microbotanical evidence concerning the early use of potato (Solanum tuberosum) within its botanical locus of origin in the high south-central Andes. The data derive from Jiskairumoko, an early village site in the western Titicaca Basin dating to the Late Archaic to Early Formative periods (∼3,400 cal y BC to 1,600 cal y BC). Because the site reflects the transition to sedentism and food production, these data may relate to potato domestication and early cultivation. Of 141 starch microremains recovered from 14 groundstone tools from Jiskairumoko, 50 are identified as consistent with cultivated or domesticated potato, based on reference to published materials and a study of wild and cultivated potato starch morphology. Along with macro- and microbotanical evidence for chenopod consumption and grinding tool data reflecting intensive use of this technology throughout site occupation, the microbotanical data reported here suggest the intensive exploitation, if not cultivation, of plant resources at Jiskairumoko. Elucidating the details of the trajectory of potato domestication is necessary for an overall understanding of the development of highland Andean agriculture, as this crop is central to the autochthonous agricultural suite. A paucity of direct botanical evidence, however, has hindered research efforts. The results of the modern and archaeological starch analyses presented here underscore the utility of this method in addressing questions related to the timing, mode, and context of potato origins.

  3. Heterogeneous Delivery of Silicate and Metal to the Earth via Large Planetesimals

    Science.gov (United States)

    Marchi, S.; Canup, R. M.; Walker, R. J.

    2017-12-01

    Earth's mantle abundances of at least some highly siderophile elements, (HSE; Re, Os, Ir, Ru, Pt, Rh, Pd, and Au), are much higher than would result from metal-silicate equilibration during terrestrial core formation, and can be better explained as a result of late accretion of a minimum of 0.5% Earth's masses after core formation was complete. Traditional models assume that HSEs delivered by late projectiles completely mixed and chemically equilibrated with the Earth's mantle. This appears likely for undifferentiated, well-mixed projectiles, or for relatively small, differentiated projectiles. However several arguments suggest that late projectiles may have been large (> 1500 km in diameter) and differentiated, and in this case, portions of the projectile's core may merge with the Earth's core, rather than being mixed into the Earth's mantle. We investigate projectile mixing with a suite of SPH simulations of differentiated planetesimal colliding with the Earth. A range of outcomes emerge from our simulations suggesting that for large impactors (>1500 km), the delivery of HSE to the Earth's mantle may be disproportionate with the overall delivery of mass. For impacts with impact angles 60°, most of the impactor core escapes for moderate impact speeds. An implication is that the late accreted mass inferred from terrestrial HSE abundances may be a substantial underestimate, by a factor 2-5. In addition, partial mixing of projectiles result in an enrichment in mantle vs core material delivered to the bulk silicate Earth, implying substantial compositional variations in the accreted mass. Such variations could produce initially localized domains in Earth's mantle with distinct, mass independent isotopic signatures, given the isotopic variability resulting from nucleosynthetic heterogeneities among genetically diverse meteorites. In general we find that larger, low angle collisions would be more likely to produce initial mantle domains of anomalous composition

  4. High velocity collisions between large dust aggregates at the limit for growing planetesimals

    Science.gov (United States)

    Wurm, G.; Teiser, J.; Paraskov, G.

    2007-08-01

    Planetesimals are km-size bodies supposed to be formed in protoplanetary disks as planetary precursors [1]. The most widely considered mechanism for their formation is based on mutual collisions of smaller bodies, a process which starts with the aggregation of (sub)-micron size dust particles. In the absence of events that lithify the growing dust aggregates, only the surface forces between dust particles provide adhesion and internal strength of the objects. It has been assumed that this might be a disadvantage as dust aggregates are readily destroyed by rather weak collisions. In fact, experimental research on dust aggregation showed that for collisions in the m/s range (sub)-mm size dust aggregates impacting a larger body do show a transition from sticking to rebound and/or fragmentation in collisions and no growth occurs at the large velocities [2, 3]. This seemed to be incompatible with typical collision velocities of small dust aggregates with m-size bodies which are expected to be on the order 50 m/s in protoplanetary disks [4]. We recently found that the experimental results cannot be scaled from m/s to tens of m/s collisions. In contrast to the assumptions and somewhat counterintuitive, it is the fragility of dust aggregates that allows growth at higher collision velocities. In impact experiments Wurm et al. [5] showed that between 13 m/s and 25 m/s a larger compact (target) body consisting of micron-size SiO2 dust particles accreted 50 % of the mass of a 1 cm dust projectile consisting of the same dust. For slower impacts the projectile only rebounded or fragmented slightly.

  5. Early Start Denver Model. Un modello Evidence Based per l’intervento educativo precoce nei Disturbi dello Spettro Autistico

    Directory of Open Access Journals (Sweden)

    Saverio Fontani

    2016-07-01

    Full Text Available The Autism Spectrum Disorders represents one of the most complex developmental disabilities for the massive deficit of communication competences. The social disability related to disorders is the main objective of the intervention of the Early Start Denver Model – ESDM (Rogers & Dawson, 2010, which can be considered as one of the most advanced models for early educational intervention according the perspective of Evidence Based Education. In this paper the theoretical foundations of the model are presented and its implications for a modern inclusive education are discussed..

  6. Fertility and early-life mortality: Evidence from smallpox vaccination in Sweden

    DEFF Research Database (Denmark)

    Ager, Philipp; Hansen, Casper Worm; Jensen, Peter Sandholt

    2018-01-01

    The smallpox vaccination method was the paramount medical innovation of the late 18th and early 19th centuries. We exploit the introduction of the smallpox vaccine in Sweden to identify the causal effect of early-life mortality on fertility. Our analysis shows that parishes in counties with highe...... a small insignificant effect on the number of surviving children and natural population growth....

  7. More evidence for a one-to-one correlation between Sprites and Early VLF perturbations

    DEFF Research Database (Denmark)

    Haldoupis, C.; Amvrosiadi, N.; Cotts, B. R. T.

    2010-01-01

    Past studies have shown a correlation between sprites and early VLF perturbations, but the reported correlation varies widely from ∼50% to 100%. The present study resolves these large discrepancies by analyzing several case studies of sprite and narrowband VLF observations, in which multiple...... VLF events. However, the one‐to‐one visible sprite to early VLF event correspondence, if viewed conversely, appears not to be always reciprocal. This is because the number of early events detected in some case studies was considerably larger than the number of visible sprites. Since the great majority...

  8. Gender Gaps in Cognitive and Non-Cognitive Skills in Early Primary Grades : Evidence from Rural Indonesia

    OpenAIRE

    Nakajima, Nozomi; Jung, Haeil; Pradhan, Menno; Hasan, Amer; Kinnell, Angela; Brinkman, Sally

    2016-01-01

    This paper examines gender gaps in cognitive and non-cognitive skills among a sample of more than 10,000 children between the ages of 6 and 9 in rural Indonesia. In terms of cognitive skills, the analysis finds evidence of gender gaps favoring girls at each age in test scores of language (0.158-0.252 standard deviations) and mathematics (0.155-0.243 standard deviations) in the early years ...

  9. Planetesimal core formation with partial silicate melting using in-situ high P, high T, deformation x-ray microtomography

    Science.gov (United States)

    Anzures, B. A.; Watson, H. C.; Yu, T.; Wang, Y.

    2017-12-01

    Differentiation is a defining moment in formation of terrestrial planets and asteroids. Smaller planetesimals likely didn't reach high enough temperatures for widescale melting. However, we infer that core formation must have occurred within a few million years from Hf-W dating. In lieu of a global magma ocean, planetesimals likely formed through inefficient percolation. Here, we used in-situ high temperature, high pressure, x-ray microtomography to track the 3-D evolution of the sample at mantle conditions as it underwent shear deformation. Lattice-Boltzmann simulations for permeability were used to characterize the efficiency of melt percolation. Mixtures of KLB1 peridotite plus 6.0 to 12.0 vol% FeS were pre-sintered to achieve an initial equilibrium microstructure, and then imaged through several consecutive cycles of heating and deformation. The maximum calculated melt segregation velocity was found to be 0.37 cm/yr for 6 vol.% FeS and 0.61 cm/year for 12 vol.% FeS, both below the minimum velocity of 3.3 cm/year required for a 100km planetesimal to fully differentiate within 3 million years. However, permeability is also a function of grain size and thus the samples having smaller grains than predicted for small planetesimals could have contributed to low permeability and also low migration velocity. The two-phase (sulfide melt and silicate melt) flow at higher melt fractions (6 vol.% and 12 vol.% FeS) was an extension of a similar study1 containing only sulfide melt at lower melt fraction (4.5 vol.% FeS). Contrary to the previous study, deformation did result in increased permeability until the sample was sheared by twisting the opposing Drickamer anvils by 360 degrees. Also, the presence of silicate melt caused the FeS melt to coalesce into less connected pathways as the experiment with 6 vol.% FeS was found to be less permeable than the one with 4.5 vol.% FeS but without any partial melt. The preliminary data from this study suggests that impacts as well as

  10. The early Gravettian in a marginal area: New evidence from SW Poland

    Czech Academy of Sciences Publication Activity Database

    Wiśniewski, A.; Płonka, T.; Jary, Z.; Lisá, Lenka; Traczyk, A.; Kufel-Diakowska, B.; Raczyk, J.; Bajer, A.

    359/360, 2 March (2015), s. 131-152 ISSN 1040-6182 Institutional support: RVO:67985831 Keywords : Early Gravettian * geoarchaeology * marginal area * mobility * Sudetes foreland Subject RIV: AC - Archeology, Anthropology, Ethnology Impact factor: 2.067, year: 2015

  11. fNIRS Evidence of Prefrontal Regulation of Frustration in Early Childhood

    OpenAIRE

    Perlman, Susan B.; Luna, Beatriz; Hein, Tyler C.; Huppert, Theodore J.

    2013-01-01

    The experience of frustration is common in early childhood, yet some children seem to possess a lower tolerance for frustration than others. Characterizing the biological mechanisms underlying a wide range of frustration tolerance observed in early childhood may inform maladaptive behavior and psychopathology that is associated with this construct. The goal of this study was to measure prefrontal correlates of frustration in 3–5 year-old children, who are not readily adaptable for typical neu...

  12. Building Evidence in Early Childhood Special Education: A Systematic Review of Replication Intervention Studies

    Science.gov (United States)

    Banerjee, Rashida; Movahedazarhouligh, Sara; Millen, Kaitlyn; Luckner, John L.

    2018-01-01

    Valid and evidence-informed practices are critical to help young children with disabilities and their families with highly effective interventions and instruction to reach their potentials. Replication research is critical for appraising research and identifying evidence-based practices. The purpose of this study was to replicate the methods used…

  13. Reactive Attachment Disorder Following Early Maltreatment: Systematic Evidence beyond the Institution

    Science.gov (United States)

    Kay, Catherine; Green, Jonathan

    2013-01-01

    Reactive Attachment Disorder (RAD) remains one of the least evidence-based areas of DSM and ICD nosology. Recent evidence from severely deprived institutional samples has informed review of RAD criteria for DSM-V; however, this data is not necessarily generalizable to expectable child environments in the developed world. We provide the first…

  14. East-West Cultural Differences in Context-Sensitivity are Evident in Early Childhood

    Science.gov (United States)

    Imada, Toshie; Carlson, Stephanie M.; Itakura, Shoji

    2013-01-01

    Accumulating evidence suggests that North Americans tend to focus on central objects whereas East Asians tend to pay more attention to contextual information in a visual scene. Although it is generally believed that such culturally divergent attention tendencies develop through socialization, existing evidence largely depends on adult samples.…

  15. Molecular Evidence for Differential Long-term Outcomes of Early Life Severe Acute Malnutrition

    Directory of Open Access Journals (Sweden)

    Allan Sheppard

    2017-04-01

    Implications of All the Available Evidence: These data are compatible with the different clinical responses to SAM arising from developmentally-induced epigenetic changes laid down largely before birth and provide evidence for the predictive adaptive response model operating in human development.

  16. Evidence for the Implementation of the Early Start Denver Model for Young Children With Autism Spectrum Disorder.

    Science.gov (United States)

    Ryberg, Kayce H

    2015-01-01

    The Early Start Denver Model (ESDM) is a manualized comprehensive therapy for toddlers with autism spectrum disorder. It emphasizes interpersonal engagement through synchrony, rhythms, and reciprocity to decrease symptom severity and accelerate cognitive, social-emotional, and language development. To systematically review evidence regarding the use of the ESDM as an intervention for young children with autism spectrum disorder. PubMed, Scopus, Web of Science, Embase, and CINAHL were searched from 2010-2015 using predetermined inclusion criteria. Study methodology, participant characteristics, and outcomes were evaluated and quality of evidence was assigned. Eight articles met inclusion criteria and consisted of two randomized controlled trials, four controlled trials, and two observational cohort studies. Evidence quality ranged from low to high. The ESDM is an effective intervention that improves cognition, language, and adaptive behavior. ESDM strategies delivered in community group settings and in the home by parents have potential to be efficacious and feasible. © The Author(s) 2015.

  17. Sexual Abuse Exposure Alters Early Processing of Emotional Words: Evidence from Event-Related Potentials

    Science.gov (United States)

    Grégoire, Laurent; Caparos, Serge; Leblanc, Carole-Anne; Brisson, Benoit; Blanchette, Isabelle

    2018-01-01

    This study aimed to compare the time course of emotional information processing between trauma-exposed and control participants, using electrophysiological measures. We conceived an emotional Stroop task with two types of words: trauma-related emotional words and neutral words. We assessed the evoked cerebral responses of sexual abuse victims without post-traumatic stress disorder (PTSD) and no abuse participants. We focused particularly on an early wave (C1/P1), the N2pc, and the P3b. Our main result indicated an early effect (55–165 ms) of emotionality, which varied between non-exposed participants and sexual abuse victims. This suggests that potentially traumatic experiences modulate early processing of emotional information. Our findings showing neurobiological alterations in sexual abuse victims (without PTSD) suggest that exposure to highly emotional events has an important impact on neurocognitive function even in the absence of psychopathology. PMID:29379428

  18. Sexual Abuse Exposure Alters Early Processing of Emotional Words: Evidence from Event-Related Potentials

    Directory of Open Access Journals (Sweden)

    Laurent Grégoire

    2018-01-01

    Full Text Available This study aimed to compare the time course of emotional information processing between trauma-exposed and control participants, using electrophysiological measures. We conceived an emotional Stroop task with two types of words: trauma-related emotional words and neutral words. We assessed the evoked cerebral responses of sexual abuse victims without post-traumatic stress disorder (PTSD and no abuse participants. We focused particularly on an early wave (C1/P1, the N2pc, and the P3b. Our main result indicated an early effect (55–165 ms of emotionality, which varied between non-exposed participants and sexual abuse victims. This suggests that potentially traumatic experiences modulate early processing of emotional information. Our findings showing neurobiological alterations in sexual abuse victims (without PTSD suggest that exposure to highly emotional events has an important impact on neurocognitive function even in the absence of psychopathology.

  19. The first concussion crisis: head injury and evidence in early American football.

    Science.gov (United States)

    Harrison, Emily A

    2014-05-01

    In the early 21st century, sports concussion has become a prominent public health problem, popularly labeled "The Concussion Crisis." Football-related concussion contributes much of the epidemiological burden and inspires much of the public awareness. Though often cast as a recent phenomenon, the crisis in fact began more than a century ago, as concussions were identified among footballers in the game's first decades. This early concussion crisis subsided-allowing the problem to proliferate-because work was done by football's supporters to reshape public acceptance of risk. They appealed to an American culture that permitted violence, shifted attention to reforms addressing more visible injuries, and legitimized football within morally reputable institutions. Meanwhile, changing demands on the medical profession made practitioners reluctant to take a definitive stance. Drawing on scientific journals, public newspapers, and personal letters of players and coaches, this history of the early crisis raises critical questions about solutions being negotiated at present.

  20. Continuity versus discontinuity of the human settlement of Europe between the late Early Pleistocene and the early Middle Pleistocene. The mandibular evidence

    Science.gov (United States)

    Bermúdez de Castro, José María; Martinón-Torres, María; Rosell, Jordi; Blasco, Ruth; Arsuaga, Juan Luís; Carbonell, Eudald

    2016-12-01

    One of the most interesting aspects of the settlement of Europe is the possible continuity or discontinuity of the populations living in this continent during the Early and Middle Pleistocene. In this paper we present an analysis of the mandibular fossil record from four important Pleistocene European sites, Gran Dolina-TD6-2 (Sierra de Atapuerca), Mauer, Arago, and Atapuerca-Sima de los Huesos. We focus this study in the recognition of key derived mandibular features that may be useful to assess the relationship among the populations represented at these sites. In order to make an approach to the ecological scenario, we also present a short review and discussion of the archaeological and paleoenvironmental evidences at that time. Our results suggest that probably there was a demographic discontinuity between the late Early Pleistocene populations (MIS 21-MIS 19), and those dated to the MIS 15. Hybridization between residents and new settlers cannot be discarded. However, some features of the Gran Dolina-TD6 hominins point to some relationship between the population represented in this site (probably dated to the MIS 21) and the European Middle Pleistocene and early Late Pleistocene populations. A hypothetical scenario is presented in order to understand this apparent contradiction with the model of discontinuity.

  1. No evidence for an early seventeenth-century Indian sighting of Kepler's supernova (SN1604)

    Science.gov (United States)

    van Gent, R. H.

    2013-03-01

    In a recent paper in this journal, Sule et al. (2011) argued that an early 17th-century Indian mural of the constellation Sagittarius with a dragon-headed tail indicated that the bright supernova of 1604 was also sighted by Indian astronomers. In this paper it will be shown that this identification is based on a misunderstanding of traditional Islamic astrological iconography and that the claim that the mural represents an early 17th-century Indian sighting of the supernova of 1604 has to be rejected.

  2. Evidence of Early Cultures in the Palpa Valleys on the South coast of Perú

    OpenAIRE

    Reindel, Markus; Isla, Johny A.

    2012-01-01

    After the pioneering work of Julio C. Tello, Frédéric Engel and John H. Rowe on the Formative and Preceramic periods, few advances have been made in the investigation of early cultural developments on the south coast of Perú. This is especially true for the Río Grande de Nasca drainage, where there is a lack of data regarding early human occupation. The Nasca-Palpa Archaeological Project aims to reconstruct the human occupation of the Palpa valleys during all Prehispanic periods. In this arti...

  3. New archaeozoological data from the Fayum "Neolithic" with a critical assessment of the evidence for early stock keeping in Egypt.

    Directory of Open Access Journals (Sweden)

    Veerle Linseele

    Full Text Available Faunal evidence from the Fayum Neolithic is often cited in the framework of early stock keeping in Egypt. However, the data suffer from a number of problems. In the present paper, large faunal datasets from new excavations at Kom K and Kom W (4850-4250 BC are presented. They clearly show that, despite the presence of domesticates, fish predominate in the animal bone assemblages. In this sense, there is continuity with the earlier Holocene occupation from the Fayum, starting ca. 7350 BC. Domesticated plants and animals appear first from approximately 5400 BC. The earliest possible evidence for domesticates in Egypt are the very controversial domesticated cattle from the 9th/8th millennium BC in the Nabta Playa-Bir Kiseiba area. The earliest domesticates found elsewhere in Egypt date to the 6th millennium BC. The numbers of bones are generally extremely low at this point in time and only caprines are present. From the 5th millennium BC, the numbers of sites with domesticates dramatically increase, more species are also involved and they are usually represented by significant quantities of bones. The data from the Fayum reflect this two phase development, with very limited evidence for domesticates in the 6th millennium BC and more abundant and clearer indications in the 5th millennium BC. Any modelling of early food production in Egypt suffers from poor amounts of data, bias due to differential preservation and visibility of sites and archaeological remains, and a lack of direct dates for domesticates. In general, however, the evidence for early stock keeping and accompanying archaeological features shows large regional variation and seems to be mainly dependent on local environmental conditions. The large numbers of fish at Kom K and Kom W reflect the proximity of Lake Qarun.

  4. Planetesimal formation by an axisymmetric radial bump of the column density of the gas in a protoplanetary disk

    Science.gov (United States)

    Onishi, Isamu K.; Sekiya, Minoru

    2017-04-01

    We investigate the effect of a radial pressure bump in a protoplanetary disk on planetesimal formation. We performed the two-dimensional numerical simulation of the dynamical interaction of solid particles and gas with an initially defined pressure bump under the assumption of axisymmetry. The aim of this work is to elucidate the effects of the stellar vertical gravity that were omitted in a previous study. Our results are very different from the previous study, which omitted the vertical gravity. Because dust particles settle toward the midplane because of the vertical gravity to form a thin dust layer, the regions outside of the dust layer are scarcely affected by the back-reaction of the dust. Hence, the gas column density keeps its initial profile with a bump, and dust particles migrate toward the bump. In addition, the turbulence due to the Kelvin-Helmholtz instability caused by the difference of the azimuthal velocities between the inside and outside of the dust layer is suppressed where the radial pressure gradient is reduced by the pressure bump. The dust settling proceeds further where the turbulence is weak, and a number of dust clumps are formed. The dust density in some clumps exceeds the Roche density. Planetesimals are considered to be formed from these clumps owing to the self-gravity.[Figure not available: see fulltext.

  5. Improving Early-Grade Literacy in East Africa: Experimental Evidence from Kenya and Uganda

    Science.gov (United States)

    Lucas, Adrienne M.; McEwan, Patrick J.; Ngware, Moses; Oketch, Moses

    2014-01-01

    Primary school enrollments have increased rapidly in sub-Saharan Africa, spurring concerns about low levels of learning. We analyze field experiments in Kenya and Uganda that assessed whether the Reading to Learn intervention, implemented by the Aga Khan Foundation in both countries, improved early-grade literacy as measured by common assessments.…

  6. Early Child Care Education: Evidence from the New Law in Chile

    Science.gov (United States)

    Castillo, Felipe Aravena; Lobos, Marta Quiroga

    2017-01-01

    In the last decade, Chile has focused on early childhood education and care (ECEC) as a key opportunity to increase student-learning outcomes and decrease socio-economic inequalities. The creation of Chile's Under-Secretariat of ECEC in 2015 highlights the relevance of this educational stage. The purpose of this study is to analyse the new law…

  7. Early Enrollees and Peer Age Effect: First Evidence from INVALSI Data

    Science.gov (United States)

    Ordine, Patrizia; Rose, Giuseppe; Sposato, Daniela

    2015-01-01

    This paper estimates peer age effect on educational outcomes of Italian pupils attending primary school by exploiting changes in enrollment rules over the last few years. The empirical procedure allows to understand if there is selection in classroom formation, arguing that in the absence of pupils sorting by early age at school entry, it is…

  8. An Evaluation of the Research Evidence on the Early Start Denver Model

    Science.gov (United States)

    Baril, Erika M.; Humphreys, Betsy P.

    2017-01-01

    The Early Start Denver Model (ESDM) has been gaining popularity as a comprehensive treatment model for children ages 12 to 60 months with autism spectrum disorders (ASD). This article evaluates the research on the ESDM through an analysis of study design and purpose; child participants; setting, intervention agents, and context; density and…

  9. Building an Evidence-Based Mental Health Program for Children with History of Early Adversity

    Science.gov (United States)

    Kroupina, Maria; Vermeulen, Marlous; Moberg, Stephanie

    2015-01-01

    Adoption is a major intervention in a child's life, however internationally adopted (IA) children remain at risk for long-term neurodevelopmental and mental health issues due to the fact that most of them have a history of early adversity prior to their adoption. In the last 20 years, extensive research with this population has increased the…

  10. Inferences on the evidence for radioactive 53Mn in the early Solar System

    International Nuclear Information System (INIS)

    Typhoon Lee

    1986-01-01

    Time-scales for various processes during the formation of the early Solar System have been inferred from data on several now-extinct radionuclides. The author examines recently reported data on an extinct nuclide, 53 Mn, and shows that the data are inconsistent with the predictions of a single-stage evolution model. Alternative interpretations of the inconsistency are discussed. (U.K.)

  11. Apprenticeship, Vocational Training, and Early Labor Market Outcomes--Evidence from East and West Germany

    Science.gov (United States)

    Riphahn, Regina T.; Zibrowius, Michael

    2016-01-01

    We study the returns to apprenticeship and vocational training for three early labor market outcomes all measured at age 25 for East and West German youths: non-employment (i.e. unemployment or out of the labor force), permanent fulltime employment, and wages. We find strong positive effects of apprenticeship and vocational training. There are no…

  12. Differences in Word Recognition between Early Bilinguals and Monolinguals: Behavioral and ERP Evidence

    Science.gov (United States)

    Lehtonen, Minna; Hulten, Annika; Rodriguez-Fornells, Antoni; Cunillera, Toni; Tuomainen, Jyrki; Laine, Matti

    2012-01-01

    We investigated the behavioral and brain responses (ERPs) of bilingual word recognition to three fundamental psycholinguistic factors, frequency, morphology, and lexicality, in early bilinguals vs. monolinguals. Earlier behavioral studies have reported larger frequency effects in bilinguals' nondominant vs. dominant language and in some studies…

  13. Early Career Teacher Professional Development: Bridging Simulation Technology with Evidence-Based Behavior Management

    Science.gov (United States)

    Shernoff, Elisa; Frazier, Stacy; Lisetti, Christine; Buche, Cedric; Lunn, Stephanie; Brown, Claire; Delmarre, Alban; Chou, Tommy; Gabbard, Joseph; Morgan, Emily

    2018-01-01

    Early career teachers working in high poverty schools face of overwhelming challenges navigating disruptive behaviors with studies highlighting behavior problems as one of the strongest predictors of turnover (Ingersoll & Smith, 2003). Simulation-based technology leverages important pedagogical strengths (e.g., realistic training context,…

  14. Early Morphological Productivity in Hungarian: Evidence from Sentence Repetition and Elicited Production

    Science.gov (United States)

    Gabor, Balint; Lukacs, Agnes

    2012-01-01

    This paper investigates early productivity of morpheme use in Hungarian children aged between 2 ; 1 and 5 ; 3. Hungarian has a rich morphology which is the core marker of grammatical functions. A new method is introduced using the novel word paradigm in a sentence repetition task with masked inflections (i.e. a disguised elicited production task).…

  15. Early Childhood Education Intervention Programs in the Netherlands: Still Searching for Empirical Evidence

    Science.gov (United States)

    Driessen, Geert

    2018-01-01

    Early childhood education (ECE) intervention programs nowadays are the core of the educational disadvantage policy in the Netherlands. They offer institutional compensatory activities to young children who lack educational stimulation in the home environment. Target groups mainly comprise children from deprived socioeconomic backgrounds and of…

  16. Multiracial Children and Poverty: Evidence from the Early Childhood Longitudinal Study of Kindergartners

    Science.gov (United States)

    Bratter, Jenifer; Kimbro, Rachel Tolbert

    2013-01-01

    Despite the recent growth in multiracial children among American children, we know very little about their well-being. Using the Early Childhood Longitudinal Study, Kindergarten Class (N?=?17,706), we evaluated the likelihood of living in poverty and near poverty for multiracial and monoracial children. Most multiracial groups have poverty or near…

  17. Evidence from Maternity Leave Expansions of the Impact of Maternal Care on Early Child Development

    Science.gov (United States)

    Baker, Michael; Milligan, Kevin

    2010-01-01

    We study the impact of maternal care on early child development using an expansion in Canadian maternity leave entitlements. Following the leave expansion, mothers who took leave spent 48-58 percent more time not working in their children's first year of life. This extra maternal care primarily crowded out home-based care by unlicensed…

  18. Early embryonic demise: no evidence of abnormal spiral artery transformation or trophoblast invasion.

    Science.gov (United States)

    Ball, E; Robson, S C; Ayis, S; Lyall, F; Bulmer, J N

    2006-03-01

    Invasion by extravillous trophoblast of uterine decidua and myometrium and the associated spiral artery 'transformation' are essential for the development of normal pregnancy. Small pilot studies of placental bed and basal plate tissues from miscarriages have suggested that impaired interstitial and endovascular trophoblast invasion may play a role in the pathogenesis of miscarriage. The hypothesis that early miscarriage is associated with reduced extravillous trophoblast invasion and spiral artery transformation was tested in a large series of placental bed biopsies containing decidua and myometrium and at least one spiral artery from early, karyotyped embryonic miscarriages (early miscarriage and also did not differ significantly from normal pregnancy. These findings suggest that failed trophoblast invasion and spiral artery transformation do not have a pivotal role in the pathogenesis of early miscarriage.

  19. Early Childhood Lead Exposure and Academic Achievement: Evidence From Detroit Public Schools, 2008–2010

    Science.gov (United States)

    Baker, Harolyn W.; Tufts, Margaret; Raymond, Randall E.; Salihu, Hamisu; Elliott, Michael R.

    2013-01-01

    Objectives. We assessed the long-term effect of early childhood lead exposure on academic achievement in mathematics, science, and reading among elementary and junior high school children. Methods. We linked early childhood blood lead testing surveillance data from the Detroit Department of Health and Wellness Promotion to educational testing data from the Detroit, Michigan, public schools. We used the linked data to investigate the effect of early childhood lead exposure on academic achievement among school-aged children, both marginally and adjusted for grade level, gender, race, language, maternal education, and socioeconomic status. Results. High blood lead levels before age 6 years were strongly associated with poor academic achievement in grades 3, 5, and 8. The odds of scoring less than proficient for those whose blood lead levels were greater than 10 micrograms per deciliter were more than twice the odds for those whose blood lead levels were less than 1 micrograms per deciliter after adjustment for potential confounders. Conclusions. Early childhood lead exposure was negatively associated with academic achievement in elementary and junior high school, after adjusting for key potential confounders. The control of lead poisoning should focus on primary prevention of lead exposure in children and development of special education programs for students with lead poisoning. PMID:23327265

  20. No evidence of Neandertal mtDNA contribution to early modern humans.

    Directory of Open Access Journals (Sweden)

    David Serre

    2004-03-01

    Full Text Available The retrieval of mitochondrial DNA (mtDNA sequences from four Neandertal fossils from Germany, Russia, and Croatia has demonstrated that these individuals carried closely related mtDNAs that are not found among current humans. However, these results do not definitively resolve the question of a possible Neandertal contribution to the gene pool of modern humans since such a contribution might have been erased by genetic drift or by the continuous influx of modern human DNA into the Neandertal gene pool. A further concern is that if some Neandertals carried mtDNA sequences similar to contemporaneous humans, such sequences may be erroneously regarded as modern contaminations when retrieved from fossils. Here we address these issues by the analysis of 24 Neandertal and 40 early modern human remains. The biomolecular preservation of four Neandertals and of five early modern humans was good enough to suggest the preservation of DNA. All four Neandertals yielded mtDNA sequences similar to those previously determined from Neandertal individuals, whereas none of the five early modern humans contained such mtDNA sequences. In combination with current mtDNA data, this excludes any large genetic contribution by Neandertals to early modern humans, but does not rule out the possibility of a smaller contribution.

  1. Slow early growers have more muscle in relation to adult activity: evidence from Cebu, Philippines.

    Science.gov (United States)

    Workman, M; McDade, T W; Adair, L S; Kuzawa, C W

    2015-12-01

    Adult skeletal muscle mass (SMM) protects against type 2 diabetes, but little is known about its developmental antecedents. We examined whether pace of early weight gain predicted adult SMM in a birth cohort from Cebu City, Philippines. In addition, we examined whether increases in SMM associated with adult muscle-building exercise varied according to the early growth. Data came from 1472 participants of the Cebu Longitudinal Health and Nutrition Survey. Weight was measured at birth and at 6-month intervals through the age of 24 months. Adult SMM was estimated from anthropometric measurements when participants were 20-22-years old. Interviews provided the information on adult exercise/lifestyle habits. SMM (mean ± s.d.) was 20.8 ± 3.9 kg (men) and 13.6 ± 3.4 kg (women). Faster early weight gain predicted a higher adult SMM. After adjustment for height and lifestyle factors, strongest associations with SMM were found for 6-12 months growth in men (β=0.17, P=0.001) and for birth weight in women (β=0.14, P=0.001). Individuals who had grown slowly displayed greater SMM in association with adult weightlifting, basketball playing and physically demanding forms of employment (men) or household chores (women). These results suggest heightened sensitivity of activity-induced muscle hypertrophy among the adults who were born light or who gained weight slowly as infants. Future research should test this finding by comparing responses of muscle mass to an intervention in slow vs fast early growers. Findings suggest that adults who display a reduced SMM following suboptimal early growth may be good candidates for new anti-diabetes interventions that promote muscle-building activities.

  2. Echocardiographic Evidence of Early Diastolic Dysfunction in Asymptomatic Children with Osteogenesis Imperfecta

    Directory of Open Access Journals (Sweden)

    Khalfan S. Al-Senaidi

    2015-11-01

    Full Text Available Objectives: Structural and functional cardiovascular abnormalities have been reported in adults with osteogenesis imperfecta (OI; however, there is a lack of paediatric literature on this topic. This study aimed to investigate cardiovascular abnormalities in children with OI in comparison to a control group. Methods: This case-control study was conducted at the Sultan Qaboos University Hospital in Muscat, Oman, between May 2013 and August 2014. Data from eight patients with OI and 24 healthy controls were compared using conventional and tissue Doppler echocardiography (TDE. Results: The OI group had significantly lower peak early mitral valve flow velocity (P = 0.027, peak a-wave reversal in the pulmonary vein (P = 0.030 and peak early diastolic velocity of the mitral valve and upper septum (P = 0.001 each. The peak late diastolic velocities of the mitral valve (P = 0.002 and the upper septum (P = 0.037 were significantly higher in the OI group; however, the peak early/late diastolic velocity ratios of the mitral valve (P = 0.002 and upper septum (P = 0.001 were significantly lower. Left ventricular dimensions and aortic and pulmonary artery diameters were larger in the OI group when indexed for body surface area. Both groups had normal systolic cardiac function. Conclusion: Children with OI had normal systolic cardiac function. However, changes in myocardial tissue Doppler velocities were suggestive of early diastolic cardiac dysfunction. They also had increased left ventricular dimensions and greater vessel diameters. These findings indicate the need for early and detailed structural and functional echocardiographic assessment and follow-up of young patients with OI.

  3. Experiences of early labour management from perspectives of women, labour companions and health professionals: A systematic review of qualitative evidence.

    Science.gov (United States)

    Beake Rm Ma Research Associate, Sarah; Chang Ba MPhil PhD Lecturer, Yan-Shing; Cheyne Rm Rgn MSc PhD Professor Of Midwifery, Helen; Spiby MPhil Rn Rm Professor Of Midwifery, Helen; Sandall Rm MSc PhD Professor Of Social Science And Women's Health, Jane; Bick, Debra

    2018-02-01

    to examine evidence of women's, labour companions' and health professionals' experiences of management of early labour to consider how this could be enhanced to better reflect women's needs. a systematic review of qualitative evidence. women in early labour with term, low risk singleton pregnancies, not booked for a planned caesarean birth or post-dates induction of labour, their labour companions, and health professionals responsible for early labour care (e.g. midwives, nurse-midwives, obstetricians, family doctors). Studies from high and middle income country settings were considered. 21 publications were included from the UK, Ireland, Scandinavia, USA, Italy and New Zealand. Key findings included the impact of communication with health professionals (most usually midwives) on women's decision making; women wanting to be listened to by sympathetic midwives who could reassure that symptoms and signs of early labour were 'normal' and offer clear advice on what to do. Antenatal preparation which included realistic information on what to expect when labour commenced was important and appreciated by women and labour companions. Views of the optimal place for women to remain and allow early labour to progress differed and the perceived benefit of support and help offered by labour companions varied. Some were supportive and helped women to relax, while others were anxious and encouraged women to seek early admission to the planned place of birth. Web-based sources of information are increasingly used by women, with mixed views of the value of information accessed. women, labour companions and health professionals find early labour difficult to manage well, with women unsure of how decisions about admission to their planned place of birth are taken. It is unclear why women are effectively left to manage this aspect of their labour with minimal guidance or support. Tailoring management to meet individual needs, with provision of effective communication could reassure

  4. Is an early retirement offer good for your health? Quasi-experimental evidence from the army.

    Science.gov (United States)

    Hallberg, Daniel; Johansson, Per; Josephson, Malin

    2015-12-01

    This paper studies empirically the consequences on health of an early retirement offer. To this end we use a targeted retirement offer to military officers 55 years of age or older. Before the offer was implemented, the normal retirement age in the Swedish defense was 60 years of age. Estimating the effect of the offer on individuals' health within the age range 56-70, we find support for a reduction in both mortality and in inpatient care as a consequence of the early retirement offer. Increasing the mandatory retirement age may thus not only have positive government income effects but also negative effects on increasing government health care expenditures. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Early processing of orthographic language membership information in bilingual visual word recognition: Evidence from ERPs.

    Science.gov (United States)

    Hoversten, Liv J; Brothers, Trevor; Swaab, Tamara Y; Traxler, Matthew J

    2017-08-01

    For successful language comprehension, bilinguals often must exert top-down control to access and select lexical representations within a single language. These control processes may critically depend on identification of the language to which a word belongs, but it is currently unclear when different sources of such language membership information become available during word recognition. In the present study, we used event-related potentials to investigate the time course of influence of orthographic language membership cues. Using an oddball detection paradigm, we observed early neural effects of orthographic bias (Spanish vs. English orthography) that preceded effects of lexicality (word vs. pseudoword). This early orthographic pop-out effect was observed for both words and pseudowords, suggesting that this cue is available prior to full lexical access. We discuss the role of orthographic bias for models of bilingual word recognition and its potential role in the suppression of nontarget lexical information. Published by Elsevier Ltd.

  6. Evidence for multiple sources of 10Be in the early solar system

    DEFF Research Database (Denmark)

    Wielandt, Daniel Kim Peel; Nagashima, Kazuhide; Krot, Alexander N.

    2012-01-01

    Beryllium-10 is a short-lived radionuclide (t 1/2 = 1.4 Myr) uniquely synthesized by spallation reactions and inferred to have been present when the solar system's oldest solids (calcium-aluminum-rich inclusions, CAIs) formed. Yet, the astrophysical site of 10Be nucleosynthesis is uncertain. We...... in the gaseous CAI-forming reservoir, or in the inclusions themselves: this indicates at least two nucleosynthetic sources of 10Be in the early solar system. The most promising locale for 10Be synthesis is close to the proto-Sun during its early mass-accreting stages, as these are thought to coincide...

  7. Can early intervention policies improve wellbeing? Evidence from a randomized controlled trial

    OpenAIRE

    Michael Daly; Liam Delaney; Orla Doyle; Nick Fitzpatrick; Christine O'Farrelly

    2014-01-01

    Many authors have proposed incorporating measures of well-being into evaluations of public policy. Yet few evaluations use experimental design or examine multiple aspects of well-being, thus the causal impact of public policies on well-being is largely unknown. In this paper we examine the effect of an intensive early intervention program on maternal well-being in a targeted disadvantaged community. Using a randomized controlled trial design we estimate and compare treatment effects on global...

  8. Can Early Intervention Policies Improve Well-being? Evidence from a randomized controlled trial

    OpenAIRE

    Daly, Michael; Delaney, Liam; Doyle, Orla; Fitzpatrick, Nick; O'Farrelly, Christine

    2014-01-01

    Many authors have proposed incorporating measures of well-being into evaluations of public policy. Yet few evaluations use experimental design or examine multiple aspects of wellbeing, thus the causal impact of public policies on well-being is largely unknown. In this paper we examine the effect of an intensive early intervention program on maternal wellbeing in a targeted disadvantaged community. Using a randomized controlled trial design we estimate and compare treatment effects on global w...

  9. New Evidences for Early Paracas Textiles and Ceramics at Cerrillos, Ica Valley, Perú

    OpenAIRE

    Splitstoser, Jeffrey; Wallace, Dwight D.; Delgado, Mercedes

    2012-01-01

    Cerrillos is an Early to Middle Paracas civic-ceremonial site located in the upper Ica Valley of Perú. The site is known for its finely plastered adobe architecture, beautifully decorated ceramics, and complex textiles, many of which are decorated with camelid hair. Cerrillos was located in a strategically important place where the mountains meet the coastal desert and the Ica River bends south, a likely intersection in a road system that connected Cerrillos to contemporary sites in the Parac...

  10. Adapt or withdraw? Evidence on technological changes and early retirement using matched worker-firm data

    OpenAIRE

    Torbjørn Hægeland; Dag Rønningen; Kjell G. Salvanes

    2007-01-01

    Abstract: Older workers typically possess older vintages of skills than younger workers, and they may suffer more from technological change. Experienced workers may nevertheless have accumulated human capital making them suitable for adopting new technologies. On the other hand, to adjust to new technologies, workers must invest in training. This may not be worthwhile for the oldest workers, and technological change may thus induce early retirement. If technological change occu...

  11. Functional Dissociation between Perception and Action Is Evident Early in Life

    Science.gov (United States)

    Hadad, Bat-Sheva; Avidan, Galia; Ganel, Tzvi

    2012-01-01

    The functional distinction between vision for perception and vision for action is well documented in the mature visual system. Ganel and colleagues recently provided direct evidence for this dissociation, showing that while visual processing for perception follows Weber's fundamental law of psychophysics, action violates this law. We tracked the…

  12. The Industrious Revolution and Early Modern Colonial Goods Trade - Evidence from the Soundtoll Online Database

    NARCIS (Netherlands)

    Uebele, Martin

    2013-01-01

    This article presents preliminary evidence of the volume of coffee trade tolled at the entry to the Baltic Sea, ca. 1700-1850, using the Soundtoll Registers Online Database (www.soundtoll.nl). The results are interpreted in the light of the “Industrious Revolution” hypothesis (De Vries 2008). The

  13. Videoconferencing of a national program for residents on evidence-based practice: early performance evaluation.

    LENUS (Irish Health Repository)

    O'Regan, Kevin

    2010-01-01

    The aim of this study was to evaluate the effectiveness of the medium of videoconferencing for the delivery of a course for radiology residents in practice-based learning (PBL), including evidence-based practice, at centers geographically separated from the principal teaching site.

  14. Early accretion of water and volatile elements to the inner Solar System: evidence from angrites.

    Science.gov (United States)

    Sarafian, Adam R; Hauri, Erik H; McCubbin, Francis M; Lapen, Thomas J; Berger, Eve L; Nielsen, Sune G; Marschall, Horst R; Gaetani, Glenn A; Righter, Kevin; Sarafian, Emily

    2017-05-28

    Inner Solar System bodies are depleted in volatile elements relative to chondrite meteorites, yet the source(s) and mechanism(s) of volatile-element depletion and/or enrichment are poorly constrained. The timing, mechanisms and quantities of volatile elements present in the early inner Solar System have vast implications for diverse processes, from planetary differentiation to the emergence of life. We report major, trace and volatile-element contents of a glass bead derived from the D'Orbigny angrite, the hydrogen isotopic composition of this glass bead and that of coexisting olivine and silicophosphates, and the 207 Pb- 206 Pb age of the silicophosphates, 4568 ± 20 Ma. We use volatile saturation models to demonstrate that the angrite parent body must have been a major body in the early inner Solar System. We further show via mixing calculations that all inner Solar System bodies accreted volatile elements with carbonaceous chondrite H and N isotope signatures extremely early in Solar System history. Only a small portion (if any) of comets and gaseous nebular H species contributed to the volatile content of the inner Solar System bodies.This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'. © 2017 The Author(s).

  15. Molecular evidence of keratin and melanosomes in feathers of the Early Cretaceous bird Eoconfuciusornis.

    Science.gov (United States)

    Pan, Yanhong; Zheng, Wenxia; Moyer, Alison E; O'Connor, Jingmai K; Wang, Min; Zheng, Xiaoting; Wang, Xiaoli; Schroeter, Elena R; Zhou, Zhonghe; Schweitzer, Mary H

    2016-12-06

    Microbodies associated with feathers of both nonavian dinosaurs and early birds were first identified as bacteria but have been reinterpreted as melanosomes. Whereas melanosomes in modern feathers are always surrounded by and embedded in keratin, melanosomes embedded in keratin in fossils has not been demonstrated. Here we provide multiple independent molecular analyses of both microbodies and the associated matrix recovered from feathers of a new specimen of the basal bird Eoconfuciusornis from the Early Cretaceous Jehol Biota of China. Our work represents the oldest ultrastructural and immunological recognition of avian beta-keratin from an Early Cretaceous (∼130-Ma) bird. We apply immunogold to identify protein epitopes at high resolution, by localizing antibody-antigen complexes to specific fossil ultrastructures. Retention of original keratinous proteins in the matrix surrounding electron-opaque microbodies supports their assignment as melanosomes and adds to the criteria employable to distinguish melanosomes from microbial bodies. Our work sheds new light on molecular preservation within normally labile tissues preserved in fossils.

  16. Interdisciplinary evidence-based recommendations for the follow-up of early stage seminomatous testicular germ cell cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Souchon, Rainer [Universitaetsklinikum Tuebingen (Germany). Dept. of Radiation Oncology; Hartmann, Michael [Universitaetskrankenhaus Eppendorf, Hamburg (Germany). Dept. of Urology; Krege, Susanne [Krankenhaus Maria-Hilf GmbH, Krefeld (Germany). Dept. of Urology; Lorch, Anja [Universitaetsklinikum Marburg (Germany). Dept. of Oncology; Mayer, Frank [Universitaetsklinikum Tuebingen (Germany). Dept. of Oncology; Santis, Maria de [KFJ-Spital, ACR-ITR VIEnna/CEADDP and LBI-ACR VIEnna-CTO, Vienna (Austria). Dept. of Oncology; Gillessen, Silke [Kantonsspital St. Gallen (Switzerland). Dept. of Medical Oncology; Beyer, Joerg [Vivantes Klinikum am Urban, Berlin (Germany). Dept. of Hemato-Oncology; Cathomas, Richard [Kantonsspital Graubuenden, Chur (Switzerland). Medical Oncology

    2011-03-15

    Purpose: To provide guidance regarding follow-up procedures after initial treatment of early stage testicular seminoma (clinical stages (CS) I-II A/B) based on current published evidence complemented by expert opinion. Methods and Material: An interdisciplinary, multinational working group consisting of urologists, medical oncologists, and radiation oncologists analyzed the published evidence regarding follow-up procedures in various stages of seminomatous and nonseminomatous testicular cancers. Focusing on radiooncological aspects, the recommendations contained herein are restricted to early stage seminoma (with radiotherapy being a standard treatment option). In particular, extent, frequency, and duration of imaging at follow-up were analyzed concerning relapse patterns, risk factors, and mode of relapse detection. Results: Active surveillance, adjuvant carboplatin or radiotherapy are equally accepted options for CS I seminoma but they result in different relapse rates and patterns. Usually relapses occur within the first 2(-6) years. Routinely performed follow-up using computerized tomography (CT) after adjuvant treatment yield only low detection rates of recurrences. Therefore, there is no evidence to maintain routine examinations every 3-4 months. After treatment of stage IIA/B, detection rates of relapses or progression identified solely by routinely performed CT during follow-up are low. Conclusion: Considering lifelong cure rates of up to 99% for patients treated for seminoma CS I-IIA/B, the negative impact of unnecessary ionizing radiation exposure has to be considered. The presented recommendations for various follow-up scenarios for early stage seminoma strongly promote the restrictive use of imaging procedures that utilize ionizing radiation (especially CT), due to its potential to induce secondary malignancies. (orig.)

  17. Laying a Firm Foundation: Embedding Evidence-Based Emergent Literacy Practices Into Early Intervention and Preschool Environments.

    Science.gov (United States)

    Terrell, Pamela; Watson, Maggie

    2018-04-05

    As part of this clinical forum on curriculum-based intervention, the goal of this tutorial is to share research about the importance of language and literacy foundations in natural environments during emergent literacy skill development, from infancy through preschool. Following an overview of intervention models in schools by Powell (2018), best practices at home, in child care, and in preschool settings are discussed. Speech-language pathologists in these settings will be provided a toolbox of best emergent literacy practices. A review of published literature in speech-language pathology, early intervention, early childhood education, and literacy was completed. Subsequently, an overview of the impact of early home and preschool literacy experiences are described. Research-based implementation of best practice is supported with examples of shared book reading and child-led literacy embedded in play within the coaching model of early intervention. Finally, various aspects of emergent literacy skill development in the preschool years are discussed. These include phonemic awareness, print/alphabet awareness, oral language skills, and embedded/explicit literacy. Research indicates that rich home literacy environments and exposure to rich oral language provide an important foundation for the more structured literacy environments of school. Furthermore, there is a wealth of evidence to support a variety of direct and indirect intervention practices in the home, child care, and preschool contexts to support and enhance all aspects of oral and written literacy. Application of this "toolbox" of strategies should enable speech-language pathologists to address the prevention and intervention of literacy deficits within multiple environments during book and play activities. Additionally, clinicians will have techniques to share with parents, child care providers, and preschool teachers for evidence-based literacy instruction within all settings during typical daily

  18. Highlighting the evidence gap: how cost-effective are interventions to improve early childhood nutrition and development?

    Science.gov (United States)

    Batura, Neha; Hill, Zelee; Haghparast-Bidgoli, Hassan; Lingam, Raghu; Colbourn, Timothy; Kim, Sungwook; Sikander, Siham; Pulkki-Brannstrom, Anni-Maria; Rahman, Atif; Kirkwood, Betty; Skordis-Worrall, Jolene

    2015-07-01

    There is growing evidence of the effectiveness of early childhood interventions to improve the growth and development of children. Although, historically, nutrition and stimulation interventions may have been delivered separately, they are increasingly being tested as a package of early childhood interventions that synergistically improve outcomes over the life course. However, implementation at scale is seldom possible without first considering the relative cost and cost-effectiveness of these interventions. An evidence gap in this area may deter large-scale implementation, particularly in low- and middle-income countries. We conduct a literature review to establish what is known about the cost-effectiveness of early childhood nutrition and development interventions. A set of predefined search terms and exclusion criteria standardized the search across five databases. The search identified 15 relevant articles. Of these, nine were from studies set in high-income countries and six in low- and middle-income countries. The articles either calculated the cost-effectiveness of nutrition-specific interventions (n = 8) aimed at improving child growth, or parenting interventions (stimulation) to improve early childhood development (n = 7). No articles estimated the cost-effectiveness of combined interventions. Comparing results within nutrition or stimulation interventions, or between nutrition and stimulation interventions was largely prevented by the variety of outcome measures used in these analyses. This article highlights the need for further evidence relevant to low- and middle-income countries. To facilitate comparison of cost-effectiveness between studies, and between contexts where appropriate, a move towards a common outcome measure such as the cost per disability-adjusted life years averted is advocated. Finally, given the increasing number of combined nutrition and stimulation interventions being tested, there is a significant need for evidence of cost

  19. Early enteral nutrition in critically ill patients with hemodynamic instability: an evidence-based review and practical advice.

    Science.gov (United States)

    Yang, Shuofei; Wu, Xingjiang; Yu, Wenkui; Li, Jieshou

    2014-02-01

    Early enteral nutrition (EEN) in critically ill patients is associated with significant benefit as well as elevated risk of complications. Concomitant use of EEN with vasopressors has been associated with nonocclusive bowel necrosis in critically ill patients with hemodynamic instability. The decision when to initiate enteral nutrition in hemodynamically unstable patients that require vasoactive substances remains a clinical dilemma. This review summarizes the effect of EEN and vasoactive agents on gastrointestinal blood flow and perfusion in critically ill patients, based on current evidence. Animal and clinical data involving simultaneous administration of EEN and vasoactive agents for hemodynamic instability are reviewed, and the factors related to the safety and effectiveness of EEN support in this patient population are analyzed. Moreover, practical recommendations are provided. Additional randomized clinical trials are warranted to provide cutting-edge evidence-based guidance about this issue for practitioners of critical care.

  20. East-West cultural differences in context-sensitivity are evident in early childhood.

    Science.gov (United States)

    Imada, Toshie; Carlson, Stephanie M; Itakura, Shoji

    2013-03-01

    Accumulating evidence suggests that North Americans tend to focus on central objects whereas East Asians tend to pay more attention to contextual information in a visual scene. Although it is generally believed that such culturally divergent attention tendencies develop through socialization, existing evidence largely depends on adult samples. Moreover, no past research has investigated the relation between context-sensitivity and other domains of cognitive development. The present study examined children in the United States and Japan (N = 175, age 4-9 years) to investigate the developmental pattern in context-sensitivity and its relation to executive function. The study found that context-sensitivity increased with age across cultures. Nevertheless, Japanese children showed significantly greater context-sensitivity than American children. Also, context-sensitivity fully mediated the cultural difference in a set-shifting executive function task, which might help explain past findings that East Asian children outperformed their American counterparts on executive function. © 2012 Blackwell Publishing Ltd.

  1. Little Evidence That Time in Child Care Causes Externalizing Problems During Early Childhood in Norway

    Science.gov (United States)

    Zachrisson, Henrik Daae; Dearing, Eric; Lekhal, Ratib; Toppelberg, Claudio O.

    2012-01-01

    Associations between maternal reports of hours in child care and children’s externalizing problems at 18 and 36 months of age were examined in a population-based Norwegian sample (n = 75,271). Within a sociopolitical context of homogenously high-quality child care, there was little evidence that high quantity of care causes externalizing problems. Using conventional approaches to handling selection bias and listwise deletion for substantial attrition in this sample, more hours in care predicted higher problem levels, yet with small effect sizes. The finding, however, was not robust to using multiple imputation for missing values. Moreover, when sibling and individual fixed-effects models for handling selection bias were used, no relation between hours and problems was evident. PMID:23311645

  2. A Total-Evidence Approach to Dating with Fossils, Applied to the Early Radiation of the Hymenoptera

    Science.gov (United States)

    Ronquist, Fredrik; Klopfstein, Seraina; Vilhelmsen, Lars; Schulmeister, Susanne; Murray, Debra L.; Rasnitsyn, Alexandr P.

    2012-01-01

    Abstract Phylogenies are usually dated by calibrating interior nodes against the fossil record. This relies on indirect methods that, in the worst case, misrepresent the fossil information. Here, we contrast such node dating with an approach that includes fossils along with the extant taxa in a Bayesian total-evidence analysis. As a test case, we focus on the early radiation of the Hymenoptera, mostly documented by poorly preserved impression fossils that are difficult to place phylogenetically. Specifically, we compare node dating using nine calibration points derived from the fossil record with total-evidence dating based on 343 morphological characters scored for 45 fossil (4--20 complete) and 68 extant taxa. In both cases we use molecular data from seven markers (∼5 kb) for the extant taxa. Because it is difficult to model speciation, extinction, sampling, and fossil preservation realistically, we develop a simple uniform prior for clock trees with fossils, and we use relaxed clock models to accommodate rate variation across the tree. Despite considerable uncertainty in the placement of most fossils, we find that they contribute significantly to the estimation of divergence times in the total-evidence analysis. In particular, the posterior distributions on divergence times are less sensitive to prior assumptions and tend to be more precise than in node dating. The total-evidence analysis also shows that four of the seven Hymenoptera calibration points used in node dating are likely to be based on erroneous or doubtful assumptions about the fossil placement. With respect to the early radiation of Hymenoptera, our results suggest that the crown group dates back to the Carboniferous, ∼309 Ma (95% interval: 291--347 Ma), and diversified into major extant lineages much earlier than previously thought, well before the Triassic. [Bayesian inference; fossil dating; morphological evolution; relaxed clock; statistical phylogenetics.] PMID:22723471

  3. Evidence for a western extension of the Angaran phytogeographic province in the Early Permian

    Energy Technology Data Exchange (ETDEWEB)

    Sunderlin, David [Department of the Geophysical Sciences, University of Chicago, Chicago, IL, 60637 (United States)

    2010-08-01

    A newly described Early Permian fossil plant assemblage in the Mt. Dall conglomerate in the Farewell terrane (Alaska Range, USA) is analyzed from a paleobiogeographic perspective. These data constitute the youngest paleontological dataset yet discovered in this terrane, represent the terrane's only predominantly terrestrial fossil assemblage, and are the only plant macrofossil remains of Early Permian age within a > 1500 km radius today. A suite of multivariate statistical analyses comparing the Mt. Dall paleoflora to similar age (Asselian-Artinskian) collections from the Angaran, Euramerican, and Cathaysian Permian phytogeographic provinces reveals that the Mt. Dall paleoflora has a paleobiogeographic affinity with Sub-Angaran plant fossil assemblages collected from Mongolia and the Primorye region of southeastern Russia. The paleoflora has dual importance in the construction and testing of hypotheses for which there are geographically and temporally few controls. First, these data may be used in association with other faunal and floral remains to test models of the assembly of Alaska, which seek, in part, an understanding of the paleogeographic and lithological origins of accreted terranes. That the Mt. Dall paleoflora indicates mixed Eurasia-North America paleobiogeographic affinity among individual taxa and plots in multivariate space with mid-latitude assemblages on northern Pangea may suggest deposition in that latitudinal belt. Second, contrary to the well-sampled fossil plant-bearing Permo-Carboniferous of the paleotropics and the northeastern temperate Pangean regions (Angaraland), terrestrial biome structure and vegetation type of northwestern Pangea are poorly known. This lack of understanding is due to the paucity of paleofloral collections from this region in this time period and the paleogeographic uncertainty of their position along the ancient active margin of Laurentia. The Mt. Dall paleoflora's phytogeographic affinity to paleobotanical

  4. Early entrance to the job market and its effect on adult health: evidence from Brazil.

    Science.gov (United States)

    Kassouf, A L; McKee, M; Mossialos, E

    2001-03-01

    To determine the effect of employment in childhood on self-reported health in adulthood. A cross-sectional household survey, with households selected through two-stage sampling, in urban and rural areas in the northeast and southeast of Brazil. A total of 4940 individuals, aged between 18 and 65 years, were included. The main outcome measure was self-reported health. There has been a marked reduction in the proportion of people starting work during childhood although, even in the youngest age group, nearly 20% of males began work when under 10. Early entrance into the labour market is strongly associated with low levels of both education and income, with income differentials remaining at later ages. Age starting work is also linked to current household income, with approximately 35% of those starting work when 15 or over currently in the top quartile of household income, compared with 12% of those starting work when under 10. Males, those living in rural areas, and non-whites are most likely to start work early. In univariate analyses, the younger a person started working, the greater the probability of reporting less than good health status as an adult. This persists through all ages, although the difference attenuates with increasing age. In multivariate analyses, adjustment for education or household income substantially reduces the effect but fails to eliminate it in several age bands up to the age of 48, indicating that age starting work has an independent effect on self-reported health in adulthood. The debate about the appropriate policy response to child labour is complex, requiring a balance between protecting the health of the child and safeguarding the income of the family. These findings indicate the need for more research on the long-term sequelae of beginning work at an early age.

  5. Abnormal early brain responses during visual search are evident in schizophrenia but not bipolar affective disorder.

    Science.gov (United States)

    VanMeerten, Nicolaas J; Dubke, Rachel E; Stanwyck, John J; Kang, Seung Suk; Sponheim, Scott R

    2016-01-01

    People with schizophrenia show deficits in processing visual stimuli but neural abnormalities underlying the deficits are unclear and it is unknown whether such functional brain abnormalities are present in other severe mental disorders or in individuals who carry genetic liability for schizophrenia. To better characterize brain responses underlying visual search deficits and test their specificity to schizophrenia we gathered behavioral and electrophysiological responses during visual search (i.e., Span of Apprehension [SOA] task) from 38 people with schizophrenia, 31 people with bipolar disorder, 58 biological relatives of people with schizophrenia, 37 biological relatives of people with bipolar disorder, and 65 non-psychiatric control participants. Through subtracting neural responses associated with purely sensory aspects of the stimuli we found that people with schizophrenia exhibited reduced early posterior task-related neural responses (i.e., Span Endogenous Negativity [SEN]) while other groups showed normative responses. People with schizophrenia exhibited longer reaction times than controls during visual search but nearly identical accuracy. Those individuals with schizophrenia who had larger SENs performed more efficiently (i.e., shorter reaction times) on the SOA task suggesting that modulation of early visual cortical responses facilitated their visual search. People with schizophrenia also exhibited a diminished P300 response compared to other groups. Unaffected first-degree relatives of people with bipolar disorder and schizophrenia showed an amplified N1 response over posterior brain regions in comparison to other groups. Diminished early posterior brain responses are associated with impaired visual search in schizophrenia and appear to be specifically associated with the neuropathology of schizophrenia. Published by Elsevier B.V.

  6. Evidence From Svalbard for Cool Episodes in Early Tertiary Arctic Climate

    Science.gov (United States)

    Spielhagen, R. F.; Tripati, A.; Mac Niocaill, C.

    2008-12-01

    The Arctic is a climatically sensitive and important region. However, very little is known about the climatic and oceanographic evolution of the area, particularly prior to the Neogene. Until recently, the Arctic was assumed to be characterized by relatively warm conditions during the early Cenozoic. The Early Tertiary sedimentary sequence on Svalbard contains several layers with coal seams and broad-leaved plants which were commonly accepted as indicators of a generally temperate-warm climate. Here we report on the intermittent occurrence of certain temperature indicators in the succession, which may represent the first northern high- latitude record of near-freezing temperatures for the early Cenozoic. Besides the findings of probably ice- rafted erratic clasts in the Paleocene and Eocene sandstones and shales, we note especially the occurrence of glendonites which are pseudomorphs of calcite after ikaite (calcium carbonate hexahydrate). Stratigraphic control for the most important glendonite layers was improved by paleomagnetic investigations on the host sediment. We measured the chemical composition of Svalbard glendonites which is almost identical to that of similar pseudomorphs from the Lower Cretaceaous of Northern Canada. Mass spectrometric analyses of the glendonite calcite gave very low carbon isotope values. These values suggest a provenance of the calcium carbonate from marine organic carbon and connect our glendonites to the precursor mineral ikaite which has similar low values. Since a variety of studies has demonstrated that ikaite is stable only at temperatures close to freezing point, we have to infer low temperatures also for the deepositional environment of which the sediments were deposited that now hold glendonites. These results imply the occurrence of cooling phases episodically during the warm background climate of the Paleocene and Eocene, suggesting that temperature variability was much greater than previously recognized.

  7. ANOTHER EVIDENCE IN SUPPORT OF THE EARLY INTRODUCTION OF EFL IN INDONESIA

    Directory of Open Access Journals (Sweden)

    Suwartono Suwartono

    2015-03-01

    > 1.960 with 140 df, at the 5% level of significance. It means that the alternative hypothesis: “a significant difference in the mastery of Junior High School between students who had received English as a compulsory course at their elementary schooling background and those who had not exists” is confirmed. Therefore, it is statistically proven that the teaching of English at Elementary Schools contributes to the students’ English achievement.   Key words: ex-post facto, achievement, early age, the t-test, and English implementa- tion.

  8. Coagulation calculations of icy planet formation around 0.1-0.5 M {sub ☉} stars: Super-Earths from large planetesimals

    Energy Technology Data Exchange (ETDEWEB)

    Kenyon, Scott J. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Bromley, Benjamin C., E-mail: skenyon@cfa.harvard.edu, E-mail: bromley@physics.utah.edu [Department of Physics, University of Utah, 201 JFB, Salt Lake City, UT 84112 (United States)

    2014-01-01

    We investigate formation mechanisms for icy super-Earth-mass planets orbiting at 2-20 AU around 0.1-0.5 M {sub ☉} stars. A large ensemble of coagulation calculations demonstrates a new formation channel: disks composed of large planetesimals with radii of 30-300 km form super-Earths on timescales of ∼1 Gyr. In other gas-poor disks, a collisional cascade grinds planetesimals to dust before the largest planets reach super-Earth masses. Once icy Earth-mass planets form, they migrate through the leftover swarm of planetesimals at rates of 0.01-1 AU Myr{sup –1}. On timescales of 10 Myr to 1 Gyr, many of these planets migrate through the disk of leftover planetesimals from semimajor axes of 5-10 AU to 1-2 AU. A few percent of super-Earths might migrate to semimajor axes of 0.1-0.2 AU. When the disk has an initial mass comparable with the minimum-mass solar nebula, scaled to the mass of the central star, the predicted frequency of super-Earths matches the observed frequency.

  9. Efficacy of Early Surgery for Neurological Improvement in Spinal Cord Injury without Radiographic Evidence of Trauma in the Elderly.

    Science.gov (United States)

    Inoue, Tomoo; Suzuki, Shinsuke; Endo, Toshiki; Uenohara, Hiroshi; Tominaga, Teiji

    2017-09-01

    The optimal timing for surgery for patients with spinal cord injury without radiographic evidence of trauma (SCIWORET) remains unclear. This is especially true in the elderly, given that most studies are done with younger patients to avoid age-related comorbidities. We aimed to compare the efficacy of early (24 hours postinjury) surgery in patients with SCIWORET aged ≥65 years. We identified patients aged ≥65 years who underwent surgery for SCIWORET between January 1995 and February 2016. The primary outcome was a change in the Japanese Orthopaedic Association (JOA) score at discharge, with a recovery of >50% defined as a favorable neurologic outcome. Logistic regression analysis was performed, and model fit was assessed using the Hosmer-Lemeshow test. Eighty patients aged ≥65 years with SCIWORET underwent surgery were enrolled. Favorable neurologic outcomes were seen in 43.3% of those who underwent early surgery, but only in 18.0% of those who underwent late surgery. Logistic regression analysis, adjusted for age, sex, comorbidities (Charlson Comorbidity Index), and JOA score, revealed that early surgery independently predicted favorable outcomes (odds ratio, 4.06; 95% confidence interval, 1.25-13.20), with excellent calibration (Hosmer-Lemeshow, P = 0.857). The present study indicated that early surgery within 24 hours of injury for elderly patients with SCIWORET could lead to more favorable neurologic improvements. We believe that chronological age alone should not be considered sufficient justification to deny patients early surgical decompression for SCIWORET. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    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. Reading front to back: MEG evidence for early feedback effects during word recognition.

    Science.gov (United States)

    Woodhead, Z V J; Barnes, G R; Penny, W; Moran, R; Teki, S; Price, C J; Leff, A P

    2014-03-01

    Magnetoencephalography studies in humans have shown word-selective activity in the left inferior frontal gyrus (IFG) approximately 130 ms after word presentation ( Pammer et al. 2004; Cornelissen et al. 2009; Wheat et al. 2010). The role of this early frontal response is currently not known. We tested the hypothesis that the IFG provides top-down constraints on word recognition using dynamic causal modeling of magnetoencephalography data collected, while subjects viewed written words and false font stimuli. Subject-specific dipoles in left and right occipital, ventral occipitotemporal and frontal cortices were identified using Variational Bayesian Equivalent Current Dipole source reconstruction. A connectivity analysis tested how words and false font stimuli differentially modulated activity between these regions within the first 300 ms after stimulus presentation. We found that left inferior frontal activity showed stronger sensitivity to words than false font and a stronger feedback connection onto the left ventral occipitotemporal cortex (vOT) in the first 200 ms. Subsequently, the effect of words relative to false font was observed on feedforward connections from left occipital to ventral occipitotemporal and frontal regions. These findings demonstrate that left inferior frontal activity modulates vOT in the early stages of word processing and provides a mechanistic account of top-down effects during word recognition.

  12. Evidence of the presence of the Zika virus in Mexico since early 2015.

    Science.gov (United States)

    Díaz-Quiñonez, José Alberto; López-Martínez, Irma; Torres-Longoria, Belem; Vázquez-Pichardo, Mauricio; Cruz-Ramírez, Edith; Ramírez-González, José Ernesto; Ruiz-Matus, Cuitláhuac; Kuri-Morales, Pablo

    2016-12-01

    To assess the possible circulation of Zika virus (ZIKV) prior to the first documented case in Mexico, we reanalyzed the stored samples from the states of Veracruz and Yucatán, which were originally collected to test for dengue (DENV) and chikungunya (CHIKV) but were negative for these viruses despite the symptomatology. The samples were originally collected between the 30 and 46 epidemiological weeks (EW) when the ZIKV was not yet declared as a Public Health Emergency of International Concern (PHEIC). From the total 4016 negative samples, a total of one hundred samples, 50 from Veracruz (CHIK - DENV - ) and 50 from Yucatán (4 CHIK - DENV - and 46 CHIK - or DENV - ), were tested for Zika virus by using RT-PCR. Results showed that in Veracruz and Yucatán, 20 % (10/50) and 70 % (35/50) were, respectively, ZIKV positive, indicating unequivocally the presence of ZIKV at least since July 2015. We also tested non-confirmed suspect measles cases from early 2015 for ZIKV by RT-PCR. Remarkably in 11 Mexican states, 86 % (18/21) were positive with the earlier symptoms onset as early as May 2015. Finally, RT-PCR analyses on RNA extracted from Aedes aegypti mosquitoes captured from January to March 2015 showed the presence of ZIKV, strongly suggesting that the vector was already carrying the virus at the start of 2015.

  13. The approximate number system and its relation to early math achievement: evidence from the preschool years.

    Science.gov (United States)

    Bonny, Justin W; Lourenco, Stella F

    2013-03-01

    Humans rely on two main systems of quantification; one is nonsymbolic and involves approximate number representations (known as the approximate number system or ANS), and the other is symbolic and allows for exact calculations of number. Despite the pervasiveness of the ANS across development, recent studies with adolescents and school-aged children point to individual differences in the precision of these representations that, importantly, have been shown to relate to symbolic math competence even after controlling for general aspects of intelligence. Such findings suggest that the ANS, which humans share with nonhuman animals, interfaces specifically with a uniquely human system of formal mathematics. Other findings, however, point to a less straightforward picture, leaving open questions about the nature and ontogenetic origins of the relation between these two systems. Testing children across the preschool period, we found that ANS precision correlated with early math achievement but, critically, that this relation was nonlinear. More specifically, the correlation between ANS precision and math competence was stronger for children with lower math scores than for children with higher math scores. Taken together, our findings suggest that early-developing connections between the ANS and mathematics may be fundamentally discontinuous. Possible mechanisms underlying such nonlinearity are discussed. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Financialization impedes climate change mitigation: Evidence from the early American solar industry.

    Science.gov (United States)

    Jerneck, Max

    2017-03-01

    The article investigates how financialization impedes climate change mitigation by examining its effects on the early history of one low-carbon industry, solar photovoltaics in the United States. The industry grew rapidly in the 1970s, as large financial conglomerates acquired independent firms. While providing needed financial support, conglomerates changed the focus from existing markets in consumer applications toward a future utility market that never materialized. Concentration of the industry also left it vulnerable to the corporate restructuring of the 1980s, when the conglomerates were dismantled and solar divisions were pared back or sold off to foreign firms. Both the move toward conglomeration, when corporations became managed as stock portfolios, and its subsequent reversal were the result of increased financial dominance over corporate governance. The American case is contrasted with the more successful case of Japan, where these changes to corporate governance did not occur. Insulated from shareholder pressure and financial turbulence, Japanese photovoltaics manufacturers continued to expand investment throughout the 1980s when their American rivals were cutting back. The study is informed by Joseph Schumpeter's theory of creative destruction and Hyman Minsky's theory of financialization, along with economic sociology. By highlighting the tenuous and conflicting relation between finance and production that shaped the early history of the photovoltaics industry, the article raises doubts about the prevailing approach to mitigate climate change through carbon pricing. Given the uncertainty of innovation and the ease of speculation, it will do little to spur low-carbon technology development without financial structures supporting patient capital.

  15. fNIRS evidence of prefrontal regulation of frustration in early childhood.

    Science.gov (United States)

    Perlman, Susan B; Luna, Beatriz; Hein, Tyler C; Huppert, Theodore J

    2014-01-15

    The experience of frustration is common in early childhood, yet some children seem to possess a lower tolerance for frustration than others. Characterizing the biological mechanisms underlying a wide range of frustration tolerance observed in early childhood may inform maladaptive behavior and psychopathology that is associated with this construct. The goal of this study was to measure prefrontal correlates of frustration in 3-5-year-old children, who are not readily adaptable for typical neuroimaging approaches, using functional near infrared spectroscopy (fNIRS). fNIRS of frontal regions were measured as frustration was induced in children through a computer game where a desired and expected prize was "stolen" by an animated dog. A fNIRS general linear model (GLM) was used to quantify the correlation of brain regions with the task and identify areas that were statistically different between the winning and frustrating test conditions. A second-level voxel-based ANOVA analysis was then used to correlate the amplitude of each individual's brain activation with measure of parent-reported frustration. Experimental results indicated increased activity in the middle prefrontal cortex during winning of a desired prize, while lateral prefrontal cortex activity increased during frustration. Further, activity increase in lateral prefrontal cortex during frustration correlated positively with parent-reported frustration tolerance. These findings point to the role of the lateral prefrontal cortex as a potential region supporting the regulation of emotion during frustration. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. 26Al-26Mg deficit dating ultramafic meteorites and silicate planetesimal differentiation in the early Solar System?

    DEFF Research Database (Denmark)

    Baker, Joel A.; Schiller, Martin; Bizzarro, Martin

    2012-01-01

    Meteorites with significantly sub-chondritic Al/Mg that formed in the first 2million years of the Solar System should be characterised by deficits in the abundance of Mg (d Mg ) due to the absence of in-growth of Mg from the decay of short-lived Al (t =0.73Myr). However, these Mg deficits...... will be small (d Mg >-0.037‰) even for material that formed at the same time as the Solar System's oldest solids - calcium-aluminium-rich inclusions - and thus measurement of these deficits is analytically challenging.Here, we report on a search for Mg deficits in three types of ultramafic meteorites...

  17. Continuity or discontinuity in the European Early Pleistocene human settlement: the Atapuerca evidence

    Science.gov (United States)

    Bermúdez de Castro, José María; Martinón-Torres, María; Blasco, Ruth; Rosell, Jordi; Carbonell, Eudald

    2013-09-01

    The nature, timing, pattern, favourable circumstances and impediments of the human occupation of the European continent during the Early Pleistocene are hot topics in Quaternary studies. In particular, the problem of the (dis) continuity of the settlement of Europe in this period is an important matter of discussion, which has been approached in the last decade from different points of view. The Gran Dolina (TD) and Sima del Elefante (TE) cave sites in the Sierra de Atapuerca, (Spain) include large and quasi-continuous stratigraphic sequences that stretch back from at least 1.2 million years ago (Ma) to the Matuyama/Brunhes boundary. The archaeological and paleontological record from these sites can help to test different hypotheses about the character of the human settlement in this region and period. Furthermore, the TD6 level has yielded a large collection of human fossil remains attributed to Homo antecessor. According to different geochronological methods, as well as to paleomagnetic and biostratigraphical analyses, these hominins belong to an age range of 0.96-0.80 Ma. Unfortunately, the finding in 2007 of some human fossil remains in the TE9 level, dated to about 1.22 Ma, was not enough to conclude whether H. antecessor had deep roots in the European Early Pleistocene. A set of derived features of H. antecessor shared with both the Neanderthal lineage and modern humans suggests that this species is related, and not far, from the most recent common ancestor (MRCA) of Homo neanderthalensis and Homo sapiens. If we assume that there was a lineal biological relationship between the TE9 and TD6 hominins, we should reconsider many of the conclusions achieved in previous paleontological and genetic studies. In addition, we would be obliged to build a highly complicated paleogeographical scenario for the origin of the MRCA. Although continuity in the settlement of Europe during the entire late Early Pleistocene is not discarded (e.g. in refuge areas), it seems that

  18. Pedogenic carbonate stable isotopic evidence for wooded habitat preference of early Pleistocene tool makers in the Turkana Basin.

    Science.gov (United States)

    Quinn, Rhonda L; Lepre, Christopher J; Feibel, Craig S; Wright, James D; Mortlock, Richard A; Harmand, Sonia; Brugal, Jean-Philip; Roche, Hélène

    2013-07-01

    The origin and evolution of early Pleistocene hominin lithic technologies in Africa occurred within the context of savanna grassland ecosystems. The Nachukui Formation of the Turkana Basin in northern Kenya, containing Oldowan and Acheulean tool assemblages and fossil evidence for early members of Homo and Paranthropus, provides an extensive spatial and temporal paleosol record of early Pleistocene savanna flora. Here we present new carbon isotopic (δ(13)CVPDB) values of pedogenic carbonates (68 nodules, 193 analyses) from the Nachukui Formation in order to characterize past vegetation structure and change through time. We compared three members (Kalochoro, Kaitio, and Natoo) at five locations spanning 2.4-1.4Ma and sampled in proximity to hominin archaeological and paleontological sites. Our results indicate diverse habitats showing a mosaic pattern of vegetation cover at each location yet demonstrate grassland expansion through time influenced by paleogeography. Kalochoro floodplains occurred adjacent to large river systems, and paleosols show evidence of C3 woodlands averaging 46-50% woody cover. Kaitio habitats were located along smaller rivers and lake margins. Paleosols yielded evidence for reduced portions of woody vegetation averaging 34-37% woody cover. Natoo environments had the highest percentage of grasslands averaging 21% woody cover near a diminishing Lake Turkana precursor. We also compared paleosol δ(13)CVPDB values of lithic archaeological sites with paleosol δ(13)CVPDB values of all environments available to hominins at 2.4-1.4Ma in the Nachukui and Koobi Fora Formations. Grassy environments became more widespread during this interval; woody canopy cover mean percentages steadily decreased by 12%. However, significantly more wooded savanna habitats were present in the vicinity of lithic archaeological sites and did not mirror the basin-wide trend of grassland spread. Hominin lithic archaeological sites consistently demonstrated woody cover

  19. EARLY STAGE OF THE CENTRAL ASIAN OROGENIC BELT BUILDING: EVIDENCES FROM THE SOUTHERN SIBERIAN CRATON

    Directory of Open Access Journals (Sweden)

    D. P. Gladkochub

    2017-01-01

    Full Text Available The origin of the Central-Asian Orogenic Belt (CAOB, especially of its northern segment nearby the southern margin of the Siberian craton (SC is directly related to development and closure of the Paleo-Asian Ocean (PAO. Signatures of early stages of the PAO evolution are recorded in the Late Precambrian sedimentary successions of the Sayan-Baikal-Patom Belt (SBPB on the southern edge of SC. These successions are spread over 2000 km and can be traced along this edge from north-west (Sayan area to south-east (Baikal area and further to north-east (Patom area. Here we present the synthesis of all available and reliable LA-ICP-MS U-Pb geochronological studies of detrital zircons from these sedimentary successions.

  20. A perceptual advantage for onomatopoeia in early word learning: Evidence from eye-tracking.

    Science.gov (United States)

    Laing, Catherine E

    2017-09-01

    A perceptual advantage for iconic forms in infant language learning has been widely reported in the literature, termed the "sound symbolism bootstrapping hypothesis" by Imai and Kita (2014). However, empirical research in this area is limited mainly to sound symbolic forms, which are very common in languages such as Japanese but less so in Indo-European languages such as English. In this study, we extended this body of research to onomatopoeia-words that are thought to be present across most of the world's languages and that are known to be dominant in infants' early lexicons. In a picture-mapping task, 10- and 11-month-old infants showed a processing advantage for onomatopoeia (e.g., woof woof) over their conventional counterparts (e.g., doggie). However, further analysis suggests that the input may play a key role in infants' experience and processing of these forms. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Direct evidence that radiation induced micronuclei of early embryos require a mitosis for expression

    International Nuclear Information System (INIS)

    Mueller, W.U.; Schlusen, I.; Streffer, C.

    1991-01-01

    The naturally synchronous development of early mouse embryos was exploited to address the question, whether micronuclei require a mitosis for expression or whether they can be expressed in the same cell cycle, in which exposure to X-rays or caffeine took place. Experiments with 2-cell and with 4-cell embryos showed that micronulcei are expressed only if a mitosis is completed. There was no indication, even after doses up to 20 Gy, that micronuclei can be expressed before the mitosis was reached, which followed exposure. Furthermore, no nuclear fragmentation pointing to apoptosis could be detected in the cycle, in which cells were exposed. The same results were obtained when caffeine (5 mM) was used as micronucleus inducing agent. (orig.)

  2. Greek states of the early historic period: systematizing the evidence contained in the Homeric poems

    Directory of Open Access Journals (Sweden)

    Olga A. Zolotnikova

    2013-06-01

    Based on the descriptions of the states occurring in the Homeric poems, it is supposed to demonstrate that, in terms of organization, a state of the early historic period presented a clear tripartite structure – a body of basileis (“kings”, a body of the elders and an assembly (“agora” of the people; an addition to those, there were also minor public offices, which could be held by representatives of the people. It is the intention of this paper to analyze these institutions with regard to their exact functions, roles, and importance in the states as described in the epic diction. In conclusion, it will be argued that a state as presented in the Homeric poems appeared as a self-governed autonomous community, which in its general features might approximate a city-state (polis; however, it was still too underdeveloped to be compared with states of that type.

  3. Can Early Intervention Improve Maternal Well-Being? Evidence from a Randomized Controlled Trial.

    Science.gov (United States)

    Doyle, Orla; Delaney, Liam; O'Farrelly, Christine; Fitzpatrick, Nick; Daly, Michael

    2017-01-01

    This study estimates the effect of a targeted early childhood intervention program on global and experienced measures of maternal well-being utilizing a randomized controlled trial design. The primary aim of the intervention is to improve children's school readiness skills by working directly with parents to improve their knowledge of child development and parenting behavior. One potential externality of the program is well-being benefits for parents given its direct focus on improving parental coping, self-efficacy, and problem solving skills, as well as generating an indirect effect on parental well-being by targeting child developmental problems. Participants from a socio-economically disadvantaged community are randomly assigned during pregnancy to an intensive 5-year home visiting parenting program or a control group. We estimate and compare treatment effects on multiple measures of global and experienced well-being using permutation testing to account for small sample size and a stepdown procedure to account for multiple testing. The intervention has no impact on global well-being as measured by life satisfaction and parenting stress or experienced negative affect using episodic reports derived from the Day Reconstruction Method (DRM). Treatment effects are observed on measures of experienced positive affect derived from the DRM and a measure of mood yesterday. The limited treatment effects suggest that early intervention programs may produce some improvements in experienced positive well-being, but no effects on negative aspects of well-being. Different findings across measures may result as experienced measures of well-being avoid the cognitive biases that impinge upon global assessments.

  4. EVIDENCE FOR MULTIPLE SOURCES OF 10Be IN THE EARLY SOLAR SYSTEM

    International Nuclear Information System (INIS)

    Wielandt, Daniel; Krot, Alexander N.; Bizzarro, Martin; Nagashima, Kazuhide; Huss, Gary R.; Ivanova, Marina A.

    2012-01-01

    Beryllium-10 is a short-lived radionuclide (t 1/2 = 1.4 Myr) uniquely synthesized by spallation reactions and inferred to have been present when the solar system's oldest solids (calcium-aluminum-rich inclusions, CAIs) formed. Yet, the astrophysical site of 10 Be nucleosynthesis is uncertain. We report Li-Be-B isotope measurements of CAIs from CV chondrites, including CAIs that formed with the canonical 26 Al/ 27 Al ratio of ∼5 × 10 –5 (canonical CAIs) and CAIs with Fractionation and Unidentified Nuclear isotope effects (FUN-CAIs) characterized by 26 Al/ 27 Al ratios much lower than the canonical value. Our measurements demonstrate the presence of four distinct fossil 10 Be/ 9 Be isochrons, lower in the FUN-CAIs than in the canonical CAIs, and variable within these classes. Given that FUN-CAI precursors escaped evaporation-recondensation prior to evaporative melting, we suggest that the 10 Be/ 9 Be ratio recorded by FUN-CAIs represents a baseline level present in presolar material inherited from the protosolar molecular cloud, generated via enhanced trapping of galactic cosmic rays. The higher and possibly variable apparent 10 Be/ 9 Be ratios of canonical CAIs reflect additional spallogenesis, either in the gaseous CAI-forming reservoir, or in the inclusions themselves: this indicates at least two nucleosynthetic sources of 10 Be in the early solar system. The most promising locale for 10 Be synthesis is close to the proto-Sun during its early mass-accreting stages, as these are thought to coincide with periods of intense particle irradiation occurring on timescales significantly shorter than the formation interval of canonical CAIs.

  5. Neuropsychological evidence for abnormal neurodevelopment associated with early-onset psychoses.

    Science.gov (United States)

    Bombin, I; Mayoral, M; Castro-Fornieles, J; Gonzalez-Pinto, A; de la Serna, E; Rapado-Castro, M; Barbeito, S; Parellada, M; Baeza, I; Graell, M; Payá, B; Arango, C

    2013-04-01

    The longitudinal neuropsychological study of first-episode early-onset psychosis (EOP) patients, whose brain maturation is still in progress at the time of illness onset, provides a unique opportunity to compare their cognitive development with that of healthy subjects, in search of specific patterns resulting from the interaction between neurodevelopmental processes and the presence of psychotic disorders. Method Seventy-five first-episode EOP patients (schizophrenia n = 35; bipolar disorder n = 17; other forms of psychosis n = 23) with a mean age of 15.53 years were assessed with a neuropsychological battery that included measures of attention, working memory, memory and executive functions within 6 months following the onset of the first psychotic symptom (baseline) and 2 years later. Psychotic symptoms were assessed at both times with the Positive and Negative Symptom Scale (PANSS). Seventy-nine healthy subjects matched for age and education served as controls. EOP patients showed significant cognitive impairment at both baseline and the 2-year follow-up, with no significant differences between diagnostic groups at either time. Both healthy controls and EOP patients improved in all cognitive measures, except for patient working memory. Improvement in patient attention lost significance after controlling for psychotic symptom reduction. No significant time/diagnosis interaction was found among patients (p > 0.405). Cognitive impairment in EOP is already present at the first episode, and cognitive development seems to be arrested early in EOP patients compared to their healthy peers, at least for some cognitive functions. These and previous similar results support the neurodevelopmental hypothesis of psychosis.

  6. Birth order and physical fitness in early adulthood: evidence from Swedish military conscription data.

    Science.gov (United States)

    Barclay, Kieron; Myrskylä, Mikko

    2014-12-01

    Physical fitness at young adult ages is an important determinant of physical health, cognitive ability, and mortality. However, few studies have addressed the relationship between early life conditions and physical fitness in adulthood. An important potential factor influencing physical fitness is birth order, which prior studies associate with several early- and later-life outcomes such as height and mortality. This is the first study to analyse the association between birth order and physical fitness in late adolescence. We use military conscription data on 218,873 Swedish males born between 1965 and 1977. Physical fitness is measured by a test of maximal working capacity, a measure of cardiovascular fitness closely related to V02max. We use linear regression with sibling fixed effects, meaning a within-family comparison, to eliminate the confounding influence of unobserved factors that vary between siblings. To understand the mechanism we further analyse whether the association between birth order and physical fitness varies by sibship size, parental socioeconomic status, birth cohort or length of the birth interval. We find a strong, negative and monotonic relationship between birth order and physical fitness. For example, third-born children have a maximal working capacity approximately 0.1 (p birth order effect does not depend on the length of the birth intervals, in two-child families a longer birth interval strengthens the advantage of the first-born. Our results illustrate the importance of birth order for physical fitness, and suggest that the first-born advantage already arises in late adolescence. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Financialization impedes climate change mitigation: Evidence from the early American solar industry

    Science.gov (United States)

    Jerneck, Max

    2017-01-01

    The article investigates how financialization impedes climate change mitigation by examining its effects on the early history of one low-carbon industry, solar photovoltaics in the United States. The industry grew rapidly in the 1970s, as large financial conglomerates acquired independent firms. While providing needed financial support, conglomerates changed the focus from existing markets in consumer applications toward a future utility market that never materialized. Concentration of the industry also left it vulnerable to the corporate restructuring of the 1980s, when the conglomerates were dismantled and solar divisions were pared back or sold off to foreign firms. Both the move toward conglomeration, when corporations became managed as stock portfolios, and its subsequent reversal were the result of increased financial dominance over corporate governance. The American case is contrasted with the more successful case of Japan, where these changes to corporate governance did not occur. Insulated from shareholder pressure and financial turbulence, Japanese photovoltaics manufacturers continued to expand investment throughout the 1980s when their American rivals were cutting back. The study is informed by Joseph Schumpeter’s theory of creative destruction and Hyman Minsky’s theory of financialization, along with economic sociology. By highlighting the tenuous and conflicting relation between finance and production that shaped the early history of the photovoltaics industry, the article raises doubts about the prevailing approach to mitigate climate change through carbon pricing. Given the uncertainty of innovation and the ease of speculation, it will do little to spur low-carbon technology development without financial structures supporting patient capital. PMID:28435862

  8. Can Early Intervention Improve Maternal Well-Being? Evidence from a Randomized Controlled Trial.

    Directory of Open Access Journals (Sweden)

    Orla Doyle

    Full Text Available This study estimates the effect of a targeted early childhood intervention program on global and experienced measures of maternal well-being utilizing a randomized controlled trial design. The primary aim of the intervention is to improve children's school readiness skills by working directly with parents to improve their knowledge of child development and parenting behavior. One potential externality of the program is well-being benefits for parents given its direct focus on improving parental coping, self-efficacy, and problem solving skills, as well as generating an indirect effect on parental well-being by targeting child developmental problems.Participants from a socio-economically disadvantaged community are randomly assigned during pregnancy to an intensive 5-year home visiting parenting program or a control group. We estimate and compare treatment effects on multiple measures of global and experienced well-being using permutation testing to account for small sample size and a stepdown procedure to account for multiple testing.The intervention has no impact on global well-being as measured by life satisfaction and parenting stress or experienced negative affect using episodic reports derived from the Day Reconstruction Method (DRM. Treatment effects are observed on measures of experienced positive affect derived from the DRM and a measure of mood yesterday.The limited treatment effects suggest that early intervention programs may produce some improvements in experienced positive well-being, but no effects on negative aspects of well-being. Different findings across measures may result as experienced measures of well-being avoid the cognitive biases that impinge upon global assessments.

  9. Lithium-isotope evidence for enhanced silicate weathering during OAE 1a (Early Aptian Selli event)

    Science.gov (United States)

    Lechler, Maria; Pogge von Strandmann, Philip A. E.; Jenkyns, Hugh C.; Prosser, Giacomo; Parente, Mariano

    2015-12-01

    An abrupt rise in temperature, forced by a massive input of CO2 into the atmosphere, is commonly invoked as the main trigger for Oceanic Anoxic Events (OAEs). Global warming initiated a cascade of palaeoenvironmental perturbations starting with increased continental weathering and an accelerated hydrological cycle that delivered higher loads of nutrients to coastal areas, stimulating biological productivity. The end-result was widespread anoxia and deposition of black shales: the hallmarks of OAEs. In order to assess the role of weathering as both an OAE initiator and terminator (via CO2 sequestration) during the Early Aptian OAE 1a (Selli Event, ∼120 Ma) the isotopic ratio of lithium isotopes was analysed in three sections of shallow-marine carbonates from the Pacific and Tethyan realms and one basinal pelagic section from the Tethyan domain. Because the isotopic composition of lithium in seawater is largely controlled by continental silicate weathering and high- and low-temperature alteration of basaltic material, a shift to lighter δ7Li values is expected to characterize OAEs. The studied sections illustrate this phenomenon: δ7Li values decrease to a minimum coincident with the negative carbon-isotope excursion that effectively records the onset of OAE 1a. A second negative δ7Li excursion occurs coeval with the minimum in strontium isotopes after the event. The striking similarity to the strontium-isotope record argues for a common driver. The formation and destruction (weathering) of an oceanic LIP could account for the parallel trend in both isotope systems. The double-spike in lithium isotopes is probably related to a change in weathering congruencies. Such a chemostratigraphy is consistent with the hypothesis that an increase in silicate weathering, in conjunction with organic-carbon burial, led to drawdown of atmospheric CO2 during the early Aptian OAE 1a.

  10. Evidence for an apartheid-like social structure in early Anglo-Saxon England.

    Science.gov (United States)

    Thomas, Mark G; Stumpf, Michael P H; Härke, Heinrich

    2006-10-22

    The role of migration in the Anglo-Saxon transition in England remains controversial. Archaeological and historical evidence is inconclusive, but current estimates of the contribution of migrants to the English population range from less than 10000 to as many as 200000. In contrast, recent studies based on Y-chromosome variation posit a considerably higher contribution to the modern English gene pool (50-100%). Historical evidence suggests that following the Anglo-Saxon transition, people of indigenous ethnicity were at an economic and legal disadvantage compared to those having Anglo-Saxon ethnicity. It is likely that such a disadvantage would lead to differential reproductive success. We examine the effect of differential reproductive success, coupled with limited intermarriage between distinct ethnic groups, on the spread of genetic variants. Computer simulations indicate that a social structure limiting intermarriage between indigenous Britons and an initially small Anglo-Saxon immigrant population provide a plausible explanation of the high degree of Continental male-line ancestry in England.

  11. Early Parallel Activation of Semantics and Phonology in Picture Naming: Evidence from a Multiple Linear Regression MEG Study.

    Science.gov (United States)

    Miozzo, Michele; Pulvermüller, Friedemann; Hauk, Olaf

    2015-10-01

    The time course of brain activation during word production has become an area of increasingly intense investigation in cognitive neuroscience. The predominant view has been that semantic and phonological processes are activated sequentially, at about 150 and 200-400 ms after picture onset. Although evidence from prior studies has been interpreted as supporting this view, these studies were arguably not ideally suited to detect early brain activation of semantic and phonological processes. We here used a multiple linear regression approach to magnetoencephalography (MEG) analysis of picture naming in order to investigate early effects of variables specifically related to visual, semantic, and phonological processing. This was combined with distributed minimum-norm source estimation and region-of-interest analysis. Brain activation associated with visual image complexity appeared in occipital cortex at about 100 ms after picture presentation onset. At about 150 ms, semantic variables became physiologically manifest in left frontotemporal regions. In the same latency range, we found an effect of phonological variables in the left middle temporal gyrus. Our results demonstrate that multiple linear regression analysis is sensitive to early effects of multiple psycholinguistic variables in picture naming. Crucially, our results suggest that access to phonological information might begin in parallel with semantic processing around 150 ms after picture onset. © The Author 2014. Published by Oxford University Press.

  12. Reviewing the current evidence supporting early B-cells as the cellular origin of Merkel cell carcinoma.

    Science.gov (United States)

    Sauer, C M; Haugg, A M; Chteinberg, E; Rennspiess, D; Winnepenninckx, V; Speel, E-J; Becker, J C; Kurz, A K; Zur Hausen, A

    2017-08-01

    Merkel cell carcinoma (MCC) is a highly malignant skin cancer characterized by early metastases and poor survival. Although MCC is a rare malignancy, its incidence is rapidly increasing in the U.S. and Europe. The discovery of the Merkel cell polyomavirus (MCPyV) has enormously impacted our understanding of its etiopathogenesis and biology. MCCs are characterized by trilinear differentiation, comprising the expression of neuroendocrine, epithelial and B-lymphoid lineage markers. To date, it is generally accepted that the initial assumption of MCC originating from Merkel cells (MCs) is unlikely. This is owed to their post-mitotic character, absence of MCPyV in MCs and discrepant protein expression pattern in comparison to MCC. Evidence from mouse models suggests that epidermal/dermal stem cells might be of cellular origin in MCC. The recently formulated hypothesis of MCC originating from early B-cells is based on morphology, the consistent expression of early B-cell lineage markers and the finding of clonal immunoglobulin chain rearrangement in MCC cells. In this review we elaborate on the cellular ancestry of MCC, the identification of which could pave the way for novel and more effective therapeutic regimens. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Early accretion of protoplanets inferred from a reduced inner solar system 26Al inventory

    DEFF Research Database (Denmark)

    Schiller, Martin; Connelly, James; Gad, Aslaug C.

    2015-01-01

    value of 5.25×10−5. Based on their similar 54Cr/52Cr ratios, most inner solar system materials likely accreted from material containing a similar 26Al/27Al ratio as the APB precursor at the time of CAI formation. To satisfy the abundant evidence for widespread planetesimal differentiation...

  14. Will small energy consumers be faster in transition? Evidence from the early shift from coal to oil in Latin America

    International Nuclear Information System (INIS)

    Rubio, M.d.Mar; Folchi, Mauricio

    2012-01-01

    This paper provide evidence of the early transition from coal to oil for 20 Latin American countries over the first half of the 20th century, which does not fit the transition experiences of large energy consumers. These small energy consumers had earlier and faster transitions than leading nations. We also provide evidence for alternative sequences (inverse, revertible) in the transition from coal to oil. Furthermore, we demonstrate that ‘leapfrogging’ allowed a set of follower economies to reach the next rung of the energy ladder (oil domination) 30 years in advance of the most developed economies. We examine these follower economies, where transition took place earlier and faster than the cases historically known, in order to understand variation within the energy transitions and to expand the array of feasible pathways of future energy transitions. We find that being a small energy consumer makes a difference for the way the energy transition takes place; but also path dependence (including trade and technological partnerships), domestic energy endowment (which dictates relative prices) and policy decisions seem to be the variables that shaped past energy transitions. - Highlights: ► We provide evidence of the early transition from coal to oil for 20 Latin American. ► We find that being a small energy consumer makes a difference for the way the energy transition takes place. ► Followers had earlier and faster transitions than leading nations. ► ‘Leapfrogging’ allowed extremely fast energy transitions. ► Alternative forms (revertible, inverse) of energy transition also exist.

  15. Isotopic homogeneity of iron in the early solar nebula.

    Science.gov (United States)

    Zhu, X K; Guo, Y; O'Nions, R K; Young, E D; Ash, R D

    2001-07-19

    The chemical and isotopic homogeneity of the early solar nebula, and the processes producing fractionation during its evolution, are central issues of cosmochemistry. Studies of the relative abundance variations of three or more isotopes of an element can in principle determine if the initial reservoir of material was a homogeneous mixture or if it contained several distinct sources of precursor material. For example, widespread anomalies observed in the oxygen isotopes of meteorites have been interpreted as resulting from the mixing of a solid phase that was enriched in 16O with a gas phase in which 16O was depleted, or as an isotopic 'memory' of Galactic evolution. In either case, these anomalies are regarded as strong evidence that the early solar nebula was not initially homogeneous. Here we present measurements of the relative abundances of three iron isotopes in meteoritic and terrestrial samples. We show that significant variations of iron isotopes exist in both terrestrial and extraterrestrial materials. But when plotted in a three-isotope diagram, all of the data for these Solar System materials fall on a single mass-fractionation line, showing that homogenization of iron isotopes occurred in the solar nebula before both planetesimal accretion and chondrule formation.

  16. Ferrous arrowheads and their oil quench hardening: Some early Indian evidence

    Science.gov (United States)

    Dube, R. K.

    2008-05-01

    A wide variety of ferrous arrowheads were in use in ancient India. Several typical chemical analyses of arrowheads found from archaeological excavation carried out at Kaushambi are reported in this paper. The average carbon content of these arrowheads varied from as low as 0.1 wt.% to approximately 0.9 wt.%. Literary evidence for oil quench hardening of ferrous arrowheads, as reported in famous Sanskrit epics—the Rāmāyana and the Mahābhārata—have been discussed in this paper. This type of quench hardening was intentionally adopted as it helped in preventing distortion and formation of quench cracks in arrowheads. The oil quench-hardened arrowheads were rubbed on stones to sharpen them, which also brought about tempering of martensite due to frictional heat.

  17. Birth Weight and Social Trust in Adulthood: Evidence for Early Calibration of Social Cognition.

    Science.gov (United States)

    Petersen, Michael Bang; Aarøe, Lene

    2015-11-01

    Social trust forms the fundamental basis for social interaction within societies. Understanding the cognitive architecture of trust and the roots of individual differences in trust is of key importance. We predicted that one of the factors calibrating individual levels of trust is the intrauterine flow of nutrients from mother to child as indexed by birth weight. Birth weight forecasts both the future external environment and the internal condition of the individual in multiple ways relevant for social cognition. Specifically, we predicted that low birth weight is utilized as a forecast of a harsh environment, vulnerable condition, or both and, consequently, reduces social trust. The results of the study reported here are consistent with this prediction. Controlling for many confounds through sibling and panel designs, we found that lower birth weight reduced social trust in adulthood. Furthermore, we obtained tentative evidence that this effect is mitigated if adult environments do not induce stress. © The Author(s) 2015.

  18. Can Targeted Intervention Mitigate Early Emotional and Behavioral Problems?: Generating Robust Evidence within Randomized Controlled Trials.

    Directory of Open Access Journals (Sweden)

    Orla Doyle

    Full Text Available This study examined the impact of a targeted Irish early intervention program on children's emotional and behavioral development using multiple methods to test the robustness of the results. Data on 164 Preparing for Life participants who were randomly assigned into an intervention group, involving home visits from pregnancy onwards, or a control group, was used to test the impact of the intervention on Child Behavior Checklist scores at 24-months. Using inverse probability weighting to account for differential attrition, permutation testing to address small sample size, and quantile regression to characterize the distributional impact of the intervention, we found that the few treatment effects were largely concentrated among boys most at risk of developing emotional and behavioral problems. The average treatment effect identified a 13% reduction in the likelihood of falling into the borderline clinical threshold for Total Problems. The interaction and subgroup analysis found that this main effect was driven by boys. The distributional analysis identified a 10-point reduction in the Externalizing Problems score for boys at the 90th percentile. No effects were observed for girls or for the continuous measures of Total, Internalizing, and Externalizing problems. These findings suggest that the impact of this prenatally commencing home visiting program may be limited to boys experiencing the most difficulties. Further adoption of the statistical methods applied here may help to improve the internal validity of randomized controlled trials and contribute to the field of evaluation science more generally.ISRCTN Registry ISRCTN04631728.

  19. Cannabis use in early adolescence: Evidence of amygdala hypersensitivity to signals of threat

    Directory of Open Access Journals (Sweden)

    Philip A. Spechler

    2015-12-01

    Full Text Available Cannabis use in adolescence may be characterized by differences in the neural basis of affective processing. In this study, we used an fMRI affective face processing task to compare a large group (n = 70 of 14-year olds with a history of cannabis use to a group (n = 70 of never-using controls matched on numerous characteristics including IQ, SES, alcohol and cigarette use. The task contained short movies displaying angry and neutral faces. Results indicated that cannabis users had greater reactivity in the bilateral amygdalae to angry faces than neutral faces, an effect that was not observed in their abstinent peers. In contrast, activity levels in the cannabis users in cortical areas including the right temporal-parietal junction and bilateral dorsolateral prefrontal cortex did not discriminate between the two face conditions, but did differ in controls. Results did not change after excluding subjects with any psychiatric symptomology. Given the high density of cannabinoid receptors in the amygdala, our findings suggest cannabis use in early adolescence is associated with hypersensitivity to signals of threat. Hypersensitivity to negative affect in adolescence may place the subject at-risk for mood disorders in adulthood.

  20. Early Adversity, RSA, and Inhibitory Control: Evidence of Children’s Neurobiological Sensitivity to Social Context

    Science.gov (United States)

    Skowron, Elizabeth A.; Cipriano-Essel, Elizabeth; Gatzke-Kopp, Lisa M.; Teti, Douglas M.; Ammerman, Robert T.

    2014-01-01

    This study examined parasympathetic physiology as a moderator of the effects of early adversity (i.e., child abuse and neglect) on children’s inhibitory control. Children’s respiratory sinus arrhythmia (RSA) was assessed during a resting baseline, two joint challenge tasks with mother, and an individual frustration task. RSA assessed during each of the joint parent–child challenge tasks moderated the effects of child maltreatment (CM) status on children’s independently-assessed inhibitory control. No moderation effect was found for RSA assessed at baseline or in the child-alone challenge task. Among CM-exposed children, lower RSA levels during the joint task predicted the lowest inhibitory control, whereas higher joint task RSA was linked to higher inhibitory control scores that were indistinguishable from those of non-CM children. Results are discussed with regard to the importance of considering context specificity (i.e., individual and caregiver contexts) in how biomarkers inform our understanding of individual differences in vulnerability among at-risk children. PMID:24142832

  1. Early adversity, RSA, and inhibitory control: evidence of children's neurobiological sensitivity to social context.

    Science.gov (United States)

    Skowron, Elizabeth A; Cipriano-Essel, Elizabeth; Gatzke-Kopp, Lisa M; Teti, Douglas M; Ammerman, Robert T

    2014-07-01

    This study examined parasympathetic physiology as a moderator of the effects of early adversity (i.e., child abuse and neglect) on children's inhibitory control. Children's respiratory sinus arrhythmia (RSA) was assessed during a resting baseline, two joint challenge tasks with mother, and an individual frustration task. RSA assessed during each of the joint parent-child challenge tasks moderated the effects of child maltreatment (CM) status on children's independently-assessed inhibitory control. No moderation effect was found for RSA assessed at baseline or in the child-alone challenge task. Among CM-exposed children, lower RSA levels during the joint task predicted the lowest inhibitory control, whereas higher joint task RSA was linked to higher inhibitory control scores that were indistinguishable from those of non-CM children. Results are discussed with regard to the importance of considering context specificity (i.e., individual and caregiver contexts) in how biomarkers inform our understanding of individual differences in vulnerability among at-risk children. © 2013 Wiley Periodicals, Inc.

  2. Cannabis use in early adolescence: Evidence of amygdala hypersensitivity to signals of threat.

    Science.gov (United States)

    Spechler, Philip A; Orr, Catherine A; Chaarani, Bader; Kan, Kees-Jan; Mackey, Scott; Morton, Aaron; Snowe, Mitchell P; Hudson, Kelsey E; Althoff, Robert R; Higgins, Stephen T; Cattrell, Anna; Flor, Herta; Nees, Frauke; Banaschewski, Tobias; Bokde, Arun L W; Whelan, Robert; Büchel, Christian; Bromberg, Uli; Conrod, Patricia; Frouin, Vincent; Papadopoulos, Dimitri; Gallinat, Jurgen; Heinz, Andreas; Walter, Henrik; Ittermann, Bernd; Gowland, Penny; Paus, Tomáš; Poustka, Luise; Martinot, Jean-Luc; Artiges, Eric; Smolka, Michael N; Schumann, Gunter; Garavan, Hugh

    2015-12-01

    Cannabis use in adolescence may be characterized by differences in the neural basis of affective processing. In this study, we used an fMRI affective face processing task to compare a large group (n=70) of 14-year olds with a history of cannabis use to a group (n=70) of never-using controls matched on numerous characteristics including IQ, SES, alcohol and cigarette use. The task contained short movies displaying angry and neutral faces. Results indicated that cannabis users had greater reactivity in the bilateral amygdalae to angry faces than neutral faces, an effect that was not observed in their abstinent peers. In contrast, activity levels in the cannabis users in cortical areas including the right temporal-parietal junction and bilateral dorsolateral prefrontal cortex did not discriminate between the two face conditions, but did differ in controls. Results did not change after excluding subjects with any psychiatric symptomology. Given the high density of cannabinoid receptors in the amygdala, our findings suggest cannabis use in early adolescence is associated with hypersensitivity to signals of threat. Hypersensitivity to negative affect in adolescence may place the subject at-risk for mood disorders in adulthood. Copyright © 2015. Published by Elsevier Ltd.

  3. Early stage second-language learning improves executive control: evidence from ERP.

    Science.gov (United States)

    Sullivan, Margot D; Janus, Monika; Moreno, Sylvain; Astheimer, Lori; Bialystok, Ellen

    2014-12-01

    A growing body of research has reported a bilingual advantage in performance on executive control tasks, but it is not known at what point in emerging bilingualism these advantages first appear. The present study investigated the effect of early stage second-language training on executive control. Monolingual English-speaking students were tested on a go-nogo task, sentence judgment task, and verbal fluency, before and after 6 months of Spanish instruction. The training group (n = 25) consisted of students enrolled in introductory Spanish and the control group (n = 30) consisted of students enrolled in introductory Psychology. After training, the Spanish group showed larger P3 amplitude on the go-nogo task and smaller P600 amplitude on the judgment task, indicating enhanced performance, with no changes for the control group and no differences between groups on behavioral measures. Results are discussed in terms of neural changes underlying executive control after brief second-language learning. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Delinquency, parental involvement, early adult criminality, and sex: Evidence of moderated mediation.

    Science.gov (United States)

    Walters, Glenn D

    2013-08-01

    One purpose of this study was to determine whether parental involvement, measured in late adolescence, mediates the relationship between delinquency in mid-adolescence and crime in early adulthood. This study's second purpose was to ascertain whether this relationship is moderated by sex, such that late adolescent parental involvement mediates the delinquency-crime relationship in females but not in males. A secondary analysis of data provided by 579 (272 males, 307 females) members of the National Longitudinal Survey of Youth-Child (NLSYC) was conducted in an effort to evaluate the possibility of moderated mediation in the relationship between delinquency at age 16, parental involvement at age 18, and criminality at age 24. Moderated mediation analysis, path analysis, and causal mediation analysis revealed the presence of a conditional indirect relationship between delinquency, parental involvement, and adult crime moderated by sex. These results are consistent with views on cumulative disadvantage and gendered pathways to crime. Copyright © 2013 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  5. Punctuated Sediment Discharge during Early Pliocene Birth of the Colorado River: Evidence from Regional Stratigraphy, Sedimentology, and Paleontology

    Science.gov (United States)

    Dorsey, Rebecca J.; O'Connell, Brennan; McDougall, Kristin; Homan, Mindy B.

    2018-01-01

    The Colorado River in the southwestern U.S. provides an excellent natural laboratory for studying the origins of a continent-scale river system, because deposits that formed prior to and during river initiation are well exposed in the lower river valley and nearby basinal sink. This paper presents a synthesis of regional stratigraphy, sedimentology, and micropaleontology from the southern Bouse Formation and similar-age deposits in the western Salton Trough, which we use to interpret processes that controlled the birth and early evolution of the Colorado River. The southern Bouse Formation is divided into three laterally persistent members: basal carbonate, siliciclastic, and upper bioclastic members. Basal carbonate accumulated in a tide-dominated marine embayment during a rise of relative sea level between 6.3 and 5.4 Ma, prior to arrival of the Colorado River. The transition to green claystone records initial rapid influx of river water and its distal clay wash load into the subtidal marine embayment at 5.4-5.3 Ma. This was followed by rapid southward progradation of the Colorado River delta, establishment of the earliest through-flowing river, and deposition of river-derived turbidites in the western Salton Trough (Wind Caves paleocanyon) between 5.3 and 5.1 Ma. Early delta progradation was followed by regional shut-down of river sand output between 5.1 and 4.8 Ma that resulted in deposition of marine clay in the Salton Trough, retreat of the delta, and re-flooding of the lower river valley by shallow marine water that deposited the Bouse upper bioclastic member. Resumption of sediment discharge at 4.8 Ma drove massive progradation of fluvial-deltaic deposits back down the river valley into the northern Gulf and Salton Trough. These results provide evidence for a discontinuous, start-stop-start history of sand output during initiation of the Colorado River that is not predicted by existing models for this system. The underlying controls on punctuated sediment

  6. Knowledge Creation as an Approach to Facilitating Evidence Informed Practice: Examining Ways to Measure the Success of Using This Method with Early Years Practitioners in Camden (London)

    Science.gov (United States)

    Brown, Chris; Rogers, Sue

    2015-01-01

    This paper has three key aims. First it examines the authors' attempts to use knowledge creation activity as a way of developing evidence informed practice amongst a learning community of 36 early years practitioners in the London Borough of Camden. Second, it seeks to illustrate how the authors approached the idea of measuring evidence use and…

  7. Evidence from neglect dyslexia for morphological decomposition at the early stages of orthographic-visual analysis

    Science.gov (United States)

    Reznick, Julia; Friedmann, Naama

    2015-01-01

    This study examined whether and how the morphological structure of written words affects reading in word-based neglect dyslexia (neglexia), and what can be learned about morphological decomposition in reading from the effect of morphology on neglexia. The oral reading of 7 Hebrew-speaking participants with acquired neglexia at the word level—6 with left neglexia and 1 with right neglexia—was evaluated. The main finding was that the morphological role of the letters on the neglected side of the word affected neglect errors: When an affix appeared on the neglected side, it was neglected significantly more often than when the neglected side was part of the root; root letters on the neglected side were never omitted, whereas affixes were. Perceptual effects of length and final letter form were found for words with an affix on the neglected side, but not for words in which a root letter appeared in the neglected side. Semantic and lexical factors did not affect the participants' reading and error pattern, and neglect errors did not preserve the morpho-lexical characteristics of the target words. These findings indicate that an early morphological decomposition of words to their root and affixes occurs before access to the lexicon and to semantics, at the orthographic-visual analysis stage, and that the effects did not result from lexical feedback. The same effects of morphological structure on reading were manifested by the participants with left- and right-sided neglexia. Since neglexia is a deficit at the orthographic-visual analysis level, the effect of morphology on reading patterns in neglexia further supports that morphological decomposition occurs in the orthographic-visual analysis stage, prelexically, and that the search for the three letters of the root in Hebrew is a trigger for attention shift in neglexia. PMID:26528159

  8. Do minimum wages improve early life health? Evidence from developing countries.

    Science.gov (United States)

    Majid, Muhammad Farhan; Mendoza Rodríguez, José M; Harper, Sam; Frank, John; Nandi, Arijit

    2016-06-01

    The impact of legislated minimum wages on the early-life health of children living in low and middle-income countries has not been examined. For our analyses, we used data from the Demographic and Household Surveys (DHS) from 57 countries conducted between 1999 and 2013. Our analyses focus on height-for-age z scores (HAZ) for children under 5 years of age who were surveyed as part of the DHS. To identify the causal effect of minimum wages, we utilized plausibly exogenous variation in the legislated minimum wages during each child's year of birth, the identifying assumption being that mothers do not time their births around changes in the minimum wage. As a sensitivity exercise, we also made within family comparisons (mother fixed effect models). Our final analysis on 49 countries reveal that a 1% increase in minimum wages was associated with 0.1% (95% CI = -0.2, 0) decrease in HAZ scores. Adverse effects of an increase in the minimum wage were observed among girls and for children of fathers who were less than 35 years old, mothers aged 20-29, parents who were married, parents who were less educated, and parents involved in manual work. We also explored heterogeneity by region and GDP per capita at baseline (1999). Adverse effects were concentrated in lower-income countries and were most pronounced in South Asia. By contrast, increases in the minimum wage improved children's HAZ in Latin America, and among children of parents working in a skilled sector. Our findings are inconsistent with the hypothesis that increases in the minimum wage unconditionally improve child health in lower-income countries, and highlight heterogeneity in the impact of minimum wages around the globe. Future work should involve country and occupation specific studies which can explore not only different outcomes such as infant mortality rates, but also explore the role of parental investments in shaping these effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Early evidence of San material culture represented by organic artifacts from Border Cave, South Africa.

    Science.gov (United States)

    d'Errico, Francesco; Backwell, Lucinda; Villa, Paola; Degano, Ilaria; Lucejko, Jeannette J; Bamford, Marion K; Higham, Thomas F G; Colombini, Maria Perla; Beaumont, Peter B

    2012-08-14

    Recent archaeological discoveries have revealed that pigment use, beads, engravings, and sophisticated stone and bone tools were already present in southern Africa 75,000 y ago. Many of these artifacts disappeared by 60,000 y ago, suggesting that modern behavior appeared in the past and was subsequently lost before becoming firmly established. Most archaeologists think that San hunter-gatherer cultural adaptation emerged 20,000 y ago. However, reanalysis of organic artifacts from Border Cave, South Africa, shows that the Early Later Stone Age inhabitants of this cave used notched bones for notational purposes, wooden digging sticks, bone awls, and bone points similar to those used by San as arrowheads. A point is decorated with a spiral groove filled with red ochre, which closely parallels similar marks that San make to identify their arrowheads when hunting. A mixture of beeswax, Euphorbia resin, and possibly egg, wrapped in vegetal fibers, dated to ∼40,000 BP, may have been used for hafting. Ornaments include marine shell beads and ostrich eggshell beads, directly dated to ∼42,000 BP. A digging stick, dated to ∼39,000 BP, is made of Flueggea virosa. A wooden poison applicator, dated to ∼24,000 BP, retains residues with ricinoleic acid, derived from poisonous castor beans. Reappraisal of radiocarbon age estimates through bayesian modeling, and the identification of key elements of San material culture at Border Cave, places the emergence of modern hunter-gatherer adaptation, as we know it, to ∼44,000 y ago.

  10. Brain MRI screening showing evidences of early central nervous system involvement in patients with systemic sclerosis.

    Science.gov (United States)

    Mohammed, Reem Hamdy A; Sabry, Yousriah Y; Nasef, Amr A

    2011-05-01

    Systemic sclerosis is a multisystem autoimmune collagen disease where structural and functional abnormalities of small blood vessels prevail. Transient ischemic attacks, ischemic stroke, and hemorrhage have been reported as primary consequence of vascular central nervous system affection in systemic sclerosis. Magnetic resonance imaging is considered to be the most sensitive diagnostic technique for detecting symptomatic and asymptomatic lesions in the brain in cases of multifocal diseases. The objective of this study is to detect subclinical as well as clinically manifest cerebral vasculopathy in patients with systemic sclerosis using magnetic resonance imaging. As much as 30 female patients with systemic sclerosis aged 27-61 years old, with disease duration of 1-9 years and with no history of other systemic disease or cerebrovascular accidents, were enrolled. Age-matched female control group of 30 clinically normal subjects, underwent brain magnetic resonance examination. Central nervous system (CNS) involvement in the form of white matter hyperintense foci of variable sizes were found in significantly abundant forms in systemic sclerosis patients on magnetic resonance evaluation than in age-related control group, signifying a form of CNS vasculopathy. Such foci showed significant correlation to clinical features of organic CNS lesion including headaches, fainting attacks and organic depression as well as to the severity of peripheral vascular disease with insignificant correlation with disease duration. In conclusion, subclinical as well as clinically manifest CNS ischemic vasculopathy is not uncommon in systemic sclerosis patients and magnetic resonance imaging is considered a sensitive noninvasive screening tool for early detection of CNS involvement in patients with systemic sclerosis.

  11. Associations of infant nutrition with insulin resistance measures in early adulthood: evidence from the Barry-Caerphilly Growth (BCG study.

    Directory of Open Access Journals (Sweden)

    Dylan M Williams

    Full Text Available Previous studies suggest that over-nutrition in early infancy may programme long-term susceptibility to insulin resistance.To assess the association of breast milk and quantity of infant formula and cows' milk intake during infancy with insulin resistance measures in early adulthood.Long-term follow-up of the Barry Caerphilly Growth cohort, into which mothers and their offspring had originally been randomly assigned, between 1972-1974, to receive milk supplementation or not. Participants were the offspring, aged 23-27 years at follow-up (n = 679. Breastfeeding and formula/cows' milk intake was recorded prospectively by nurses. The main outcomes were insulin sensitivity (ISI(0 and insulin secretion (CIR(30.573 (84% individuals had valid glucose and insulin results and complete covariate information. There was little evidence of associations of breastfeeding versus any formula/cows' milk feeding or of increasing quartiles of formula/cows' milk consumption during infancy (<3 months with any outcome measure in young adulthood. In fully adjusted models, the differences in outcomes between breastfeeding versus formula/cows' milk feeding at 3 months were: fasting glucose (-0.07 mmol/l; 95% CI: -0.19, 0.05; fasting insulin (8.0%; -8.7, 27.6; ISI(0 (-6.1%; -11.3, 12.1 and CIR(30 (3.8%; -19.0, 32.8. There was also little evidence that increasing intakes of formula/cows' milk at 3 months were associated with fasting glucose (increase per quartile of formula/cows' milk intake = 0.00 mmol/l; -0.03, 0.03; fasting insulin (0.8%; -3.2, 5.1; ISI (0 (-0.9%; -5.1, 3.5 and CIR(30 (-2.6%; -8.4, 3.6.We found no evidence that increasing consumption of formula/cows' milk in early infancy was associated with insulin resistance in young adulthood.

  12. Autism as early neurodevelopmental disorder: evidence for an sAPPα-mediated anabolic pathway

    Directory of Open Access Journals (Sweden)

    Debomoy K Lahiri

    2013-06-01

    Full Text Available Autism is a neurodevelopmental disorder marked by social skills and communication deficits and interfering repetitive behavior. Intellectual disability often accompanies autism. In addition to behavioral deficits, autism is characterized by neuropathology and brain overgrowth. Increased intracranial volume often accompanies this brain growth. We have found that the Alzheimer’s disease (AD associated amyloid-β precursor protein (APP, especially its neuroprotective processing product, secreted APP α (sAPPα, is elevated in persons with autism. This has led to the anabolic hypothesis of autism etiology, in which neuronal overgrowth in the brain results in interneuronal misconnections that may underlie multiple autism symptoms. We review the contribution of research in brain volume and of APP to the anabolic hypothesis, and relate APP to other proteins and pathways that have already been directly associated with autism, such as fragile X mental retardation protein (FMRP, Ras small GTPase/Extracellular Signal-Regulated Kinase (Ras/ERK, and phosphoinositide 3 kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR. We also present additional evidence of MRI intracranial measurements in favor of the anabolic hypothesis. Finally, since it appears that APP’s involvement in autism is part of a multi-partner network, we extend this concept into the inherently interactive realm of epigenetics. We speculate that the underlying molecular abnormalities that influence APP’s contribution to autism are epigenetic markers overlaid onto potentially vulnerable gene sequences due to environmental influence.

  13. Autism as early neurodevelopmental disorder: evidence for an sAPPα-mediated anabolic pathway.

    Science.gov (United States)

    Lahiri, Debomoy K; Sokol, Deborah K; Erickson, Craig; Ray, Balmiki; Ho, Chang Y; Maloney, Bryan

    2013-01-01

    Autism is a neurodevelopmental disorder marked by social skills and communication deficits and interfering repetitive behavior. Intellectual disability often accompanies autism. In addition to behavioral deficits, autism is characterized by neuropathology and brain overgrowth. Increased intracranial volume often accompanies this brain growth. We have found that the Alzheimer's disease (AD) associated amyloid-β precursor protein (APP), especially its neuroprotective processing product, secreted APP α, is elevated in persons with autism. This has led to the "anabolic hypothesis" of autism etiology, in which neuronal overgrowth in the brain results in interneuronal misconnections that may underlie multiple autism symptoms. We review the contribution of research in brain volume and of APP to the anabolic hypothesis, and relate APP to other proteins and pathways that have already been directly associated with autism, such as fragile X mental retardation protein, Ras small GTPase/extracellular signal-regulated kinase, and phosphoinositide 3 kinase/protein kinase B/mammalian target of rapamycin. We also present additional evidence of magnetic resonance imaging intracranial measurements in favor of the anabolic hypothesis. Finally, since it appears that APP's involvement in autism is part of a multi-partner network, we extend this concept into the inherently interactive realm of epigenetics. We speculate that the underlying molecular abnormalities that influence APP's contribution to autism are epigenetic markers overlaid onto potentially vulnerable gene sequences due to environmental influence.

  14. Dietary options and behavior suggested by plant biomarker evidence in an early human habitat

    Science.gov (United States)

    Magill, Clayton R.; Ashley, Gail M.; Domínguez-Rodrigo, Manuel; Freeman, Katherine H.

    2016-03-01

    The availability of plants and freshwater shapes the diets and social behavior of chimpanzees, our closest living relative. However, limited evidence about the spatial relationships shared between ancestral human (hominin) remains, edible resources, refuge, and freshwater leaves the influence of local resources on our species' evolution open to debate. Exceptionally well-preserved organic geochemical fossils-biomarkers-preserved in a soil horizon resolve different plant communities at meter scales across a contiguous 25,000 m2 archaeological land surface at Olduvai Gorge from about 2 Ma. Biomarkers reveal hominins had access to aquatic plants and protective woods in a patchwork landscape, which included a spring-fed wetland near a woodland that both were surrounded by open grassland. Numerous cut-marked animal bones are located within the wooded area, and within meters of wetland vegetation delineated by biomarkers for ferns and sedges. Taken together, plant biomarkers, clustered bone debris, and hominin remains define a clear spatial pattern that places animal butchery amid the refuge of an isolated forest patch and near freshwater with diverse edible resources.

  15. Beverage intake and obesity in early childhood: evidence form primary health care clients in Northwest Argentina.

    Science.gov (United States)

    Alderete, E; Bejarano, I; Rodríguez, A

    2015-12-07

    Sugar sweetened beverages (SSB) are thought to play an important role in weight gain. We examined the relationship between the intake of caloric and noncaloric beverages (SSB and water) and the nutritional status of children. In 2014, we randomly selected 16 public health clinics in four cities of Northwest Argentina and conducted a survey among mothers of children 0-6 years of age. Children's beverage intake was ascertained by 24-h dietary recall provided by the mothers. Children's weight and height measures were obtained from clinic's registries. We calculated the body mass index using the International Obesity Task Force standards. The analysis included 562 children 25 months to 6 years of age with normal or above normal nutritional status. Children's beverage consumption was as follows, water 81.8%, carbonated soft drinks (CSD) 49.7%, coffee/tea/cocoa 44.0%, artificial fruit drinks 35.6%, flavored water 17.9%, natural fruit juice 14.5%. In multivariate logistic regression models the likelihood of being obese v. being overweight or having normal weight doubled with an intake of one to five glasses of CSD (OR=2.2) and increased by more than three-fold with an intake of more than five glasses (OR=3.5). Drinking more than five glasses of water decreased the likelihood of being obese by less than half (OR=0.3). The percentage of children drinking more than five glasses of other beverages was low (3.3-0.9%) and regression models did not yield significant results. The study contributed evidence for reducing children's CSD intake and for promoting water consumption, together with the implementation of comprehensive regulatory public health policies.

  16. Evidence for similar early but not late representation of possible and impossible objects

    Science.gov (United States)

    Freud, Erez; Hadad, Bat-Sheva; Avidan, Galia; Ganel, Tzvi

    2015-01-01

    The perceptual processes that mediate the ability to efficiently represent object 3D structure are still not fully understood. The current study was aimed to shed light on these processes by utilizing spatially possible and impossible objects that could not be created in real 3D space. Despite being perceived as exceptionally unusual, impossible objects still possess fundamental Gestalt attributes and valid local depth cues that may support their initial successful representation. Based on this notion and on recent findings from our lab, we hypothesized that the initial representation of impossible objects would involve common mechanisms to those mediating typical object perception while the perceived differences between possible and impossible objects would emerge later along the processing hierarchy. In Experiment 1, participants preformed same/different classifications of two markers superimposed on a display containing two objects (possible or impossible). Faster reaction times were observed for displays in which the markers were superimposed on the same object (“object-based benefit”). Importantly, this benefit was similar for possible and impossible objects, suggesting that the representations of the two object categories rely on similar perceptual organization processes. Yet, responses for impossible objects were slower compared to possible objects. Experiment 2 was designed to examine the origin of this effect. Participants classified the location of two markers while exposure duration was manipulated. A similar pattern of performance was found for possible and impossible objects for the short exposure duration, with differences in accuracy between these two types of objects emerging only for longer exposure durations. Overall, these findings provide evidence that the representation of object structure relies on a multi-level process and that object impossibility selectively impairs the rendering of fine-detailed description of object structure. PMID

  17. Breast Density Notification Legislation and Breast Cancer Stage at Diagnosis: Early Evidence from the SEER Registry.

    Science.gov (United States)

    Richman, Ilana; Asch, Steven M; Bendavid, Eran; Bhattacharya, Jay; Owens, Douglas K

    2017-06-01

    Twenty-eight states have passed breast density notification laws, which require physicians to inform women of a finding of dense breasts on mammography. To evaluate changes in breast cancer stage at diagnosis after enactment of breast density notification legislation. Using a difference-in-differences analysis, we examined changes in stage at diagnosis among women with breast cancer in Connecticut, the first state to enact legislation, compared to changes among women in control states. We used data from the Surveillance, Epidemiology, and End Results Program (SEER) registry, 2005-2013. Women ages 40-74 with breast cancer. Breast density notification legislation, enacted in Connecticut in October of 2009. Breast cancer stage at diagnosis. Our study included 466,930 women, 25,592 of whom lived in Connecticut. Legislation was associated with a 1.38-percentage-point (95 % CI 0.12 to 2.63) increase in the proportion of women in Connecticut versus control states who had localized invasive cancer at the time of diagnosis, and a 1.12-percentage-point (95 % CI -2.21 to -0.08) decline in the proportion of women with ductal carcinoma in situ at diagnosis. Breast density notification legislation was not associated with a change in the proportion of women in Connecticut versus control states with regional-stage (-0.09 percentage points, 95 % CI -1.01 to 1.02) or metastatic disease (-0.24, 95 % CI -0.75 to 0.28). County-level analyses and analyses limited to women younger than 50 found no statistically significant associations. Single intervention state, limited follow-up, potential confounding from unobserved trends. Breast density notification legislation in Connecticut was associated with a small increase in the proportion of women diagnosed with localized invasive breast cancer in individual-level but not county-level analyses. Whether this finding reflects potentially beneficial early detection or potentially harmful overdiagnosis is not known. Legislation was not

  18. Does early-life income inequality predict self-reported health in later life? Evidence from the United States.

    Science.gov (United States)

    Lillard, Dean R; Burkhauser, Richard V; Hahn, Markus H; Wilkins, Roger

    2015-03-01

    We investigate the association between adult health and the income inequality they experienced as children up to 80 years earlier. Our inequality data track shares of national income held by top percentiles from 1913 to 2009. We average those data over the same early-life years and merge them to individual data from the Panel Study of Income Dynamics data for 1984-2009. Controlling for demographic and economic factors, we find both men and women are statistically more likely to report poorer health if income was more unequally distributed during the first years of their lives. The association is robust to alternative specifications of income inequality and time trends and remains significant even when we control for differences in overall childhood health. Our results constitute prima facie evidence that adults' health may be adversely affected by the income inequality they experienced as children. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Thallium isotope evidence for a permanent increase in marine organic carbon export in the early Eocene

    Science.gov (United States)

    Nielsen, S.G.; Mar-Gerrison, S.; Gannoun, A.; LaRowe, D.; Klemm, V.; Halliday, A.N.; Burton, K.W.; Hein, J.R.

    2009-01-01

    The first high resolution thallium (Tl) isotope records in two ferromanganese crusts (Fe-Mn crusts), CD29 and D11 from the Pacific Ocean are presented. The crusts record pronounced but systematic changes in 205Tl/203Tl that are unlikely to reflect diagenetic overprinting or changes in isotope fractionation between seawater and Fe-Mn crusts. It appears more likely that the Fe-Mn crusts track the Tl isotope composition of seawater over time. The present-day oceanic residence time of Tl is estimated to be about 20,000??yr, such that the isotopic composition should reflect ocean-wide events. New and published Os isotope data are used to construct age models for these crusts that are consistent with each other and significantly different from previous age models. Application of these age models reveals that the Tl isotope composition of seawater changed systematically between ~ 55??Ma and ~ 45??Ma. Using a simple box model it is shown that the present day Tl isotope composition of seawater depends almost exclusively on the ratio between the two principal output fluxes of marine Tl. These fluxes are the rate of removal of Tl from seawater via scavenging by authigenic Fe-Mn oxyhydroxide precipitation and the uptake rate of Tl during low temperature alteration of oceanic crust. It is highly unlikely that the latter has changed greatly. Therefore, assuming that the marine Tl budget has also not changed significantly during the Cenozoic, the low 205Tl/203Tl during the Paleocene is best explained by a more than four-fold higher sequestration of Tl by Fe-Mn oxyhydroxides compared with at the present day. The calculated Cenozoic Tl isotopic seawater curve displays a striking similarity to that of S, providing evidence that both systems may have responded to the same change in the marine environment. A plausible explanation is a marked and permanent increase in organic carbon export from ~ 55??Ma to ~ 45??Ma, which led to higher pyrite burial rates and a significantly reduced

  20. Early evidence (late 2nd millennium BCE of plant-based dyeing of textiles from Timna, Israel.

    Directory of Open Access Journals (Sweden)

    Naama Sukenik

    Full Text Available In this article, we focus on the analysis of dyed textile fragments uncovered at an early Iron Age (11th-10th centuries BCE copper smelting site during new excavations in the Timna Valley conducted by the Central Timna Valley (CTV Project, as well as those found by the Arabah Expedition at the Hathor Temple (Site 200, dated to the Late Bronze/early Iron Ages (13th-11th centuries BCE. Analysis by HPLC-DAD identified two organic dyestuffs, Rubia tinctorum L. and indigotin, from a plant source (probably Isatis tinctoria L.. They are among the earliest plants known in the dyeing craft and cultivated primarily for this purpose. This study provides the earliest evidence of textiles dyed utilizing a chemical dyeing process based on an industrial dyeing plant from the Levant. Moreover, our results shed new light on the society operating the copper mines at the time, suggesting the existence of an elite that was interested in these high quality textiles and invested efforts in procuring them by long-distance trade.

  1. Early evidence (late 2nd millennium BCE) of plant-based dyeing of textiles from Timna, Israel.

    Science.gov (United States)

    Sukenik, Naama; Iluz, David; Amar, Zohar; Varvak, Alexander; Workman, Vanessa; Shamir, Orit; Ben-Yosef, Erez

    2017-01-01

    In this article, we focus on the analysis of dyed textile fragments uncovered at an early Iron Age (11th-10th centuries BCE) copper smelting site during new excavations in the Timna Valley conducted by the Central Timna Valley (CTV) Project, as well as those found by the Arabah Expedition at the Hathor Temple (Site 200), dated to the Late Bronze/early Iron Ages (13th-11th centuries BCE). Analysis by HPLC-DAD identified two organic dyestuffs, Rubia tinctorum L. and indigotin, from a plant source (probably Isatis tinctoria L.). They are among the earliest plants known in the dyeing craft and cultivated primarily for this purpose. This study provides the earliest evidence of textiles dyed utilizing a chemical dyeing process based on an industrial dyeing plant from the Levant. Moreover, our results shed new light on the society operating the copper mines at the time, suggesting the existence of an elite that was interested in these high quality textiles and invested efforts in procuring them by long-distance trade.

  2. The early printed Books of Hours in the Grey Collection in Cape Town: evidence of an information revolution

    Directory of Open Access Journals (Sweden)

    F C Steyn

    2014-11-01

    Full Text Available Printed books of hours, the best-seller of the late medieval trade in books, provide evidence of an information revolution equal to that occasioned by the Internet today. The Grey Collection of the National Library in Cape Town possesses eight books of hours, printed between 1498 and 1530, and they are almost completely unknown. Yet these valuable incunabula, all of them printed on vellum with hand-painted initials, and some of them with hand-painted miniatures, are of importance to anybody interested in books, the history of the book, the dissemination of information, the art of the late 15th to the early 16th centuries and early printing. They are also religious books, and of value to people interested in that discipline. The books are therefore eminently suitable as subjects for transdisciplinary research through which the subjects of history, sociology, art and religion can be drawn together. Two of these books, printed by Thielman Kerver in Paris, are discussed in detail in this article. The books are especially remarkable for their many illustrations that include pictures around the borders of each page as well as full-page illustrations. The pictures are neither metal cuts nor woodcuts, as were usual in that period, but relief prints. The most important part of the texts is a sequence of prayers to the Virgin Mary. Soon after these books were printed , in 1571, Pope Pius V prohibited the use of all existing books of hours.

  3. Glial alterations from early to late stages in a model of Alzheimer's disease: Evidence of autophagy involvement in Aβ internalization.

    Science.gov (United States)

    Pomilio, Carlos; Pavia, Patricio; Gorojod, Roxana Mayra; Vinuesa, Angeles; Alaimo, Agustina; Galvan, Veronica; Kotler, Monica Lidia; Beauquis, Juan; Saravia, Flavia

    2016-02-01

    Alzheimer's disease (AD) is a progressive neurodegenerative disease without effective therapy. Brain amyloid deposits are classical histopathological hallmarks that generate an inflammatory reaction affecting neuronal and glial function. The identification of early cell responses and of brain areas involved could help to design new successful treatments. Hence, we studied early alterations of hippocampal glia and their progression during the neuropathology in PDAPP-J20 transgenic mice, AD model, at 3, 9, and 15 months (m) of age. At 3 m, before deposits formation, microglial Iba1+ cells from transgenic mice already exhibited signs of activation and larger soma size in the hilus, alterations appearing later on stratum radiatum. Iba1 immunohistochemistry revealed increased cell density and immunoreactive area in PDAPP mice from 9 m onward selectively in the hilus, in coincidence with prominent amyloid Congo red + deposition. At pre-plaque stages, GFAP+ astroglia showed density alterations while, at an advanced age, the presence of deposits was associated with important glial volume changes and apparently being intimately involved in amyloid degradation. Astrocytes around plaques were strongly labeled for LC3 until 15 m in Tg mice, suggestive of increased autophagic flux. Moreover, β-Amyloid fibrils internalization by astrocytes in in vitro conditions was dependent on autophagy. Co-localization of Iba1 with ubiquitin or p62 was exclusively found in microglia contacting deposits from 9 m onward, suggesting torpid autophagy. Our work characterizes glial changes at early stages of the disease in PDAPP-J20 mice, focusing on the hilus as an especially susceptible hippocampal subfield, and provides evidence that glial autophagy could play a role in amyloid processing at advanced stages. © 2015 Wiley Periodicals, Inc.

  4. Practical considerations on the introduction of sacubitril/valsartan in clinical practice: Current evidence and early experience.

    Science.gov (United States)

    Farmakis, Dimitrios; Bistola, Vassiliki; Karavidas, Apostolos; Parissis, John

    2016-11-15

    The combination of neprilysin inhibitor sacubitril with the angiotensin II receptor 1 blocker valsartan is the first agent from the angiotensin receptor neprilysin inhibitors (ARNI) class authorized for clinical use in heart failure (HF) patients with reduced ejection fraction (HFrEF). Sacubitril/valsartan resulted in 20% reduction in the incidence rate of death or HF hospitalization compared to enalapril in symptomatic HFrEF patients in the seminal PARADIGM-HF trial. As a result, the recently updated European and American HF guidelines granted this agent a class IB indication for the treatment of ambulatory/chronic symptomatic HFrEF patients. However, translating the positive results of trials into true clinical benefit is often challenging. This is particularly true in the case of sacubitril/valsartan, as HF is a heterogeneous syndrome including many severely ill patients who are prone to decompensation, while this new agent comes to replace a cornerstone of current evidence-based HF therapy. In the present paper, we address a number of practical issues regarding the introduction of sacubitril/valsartan and propose an algorithm based on available evidence and early clinical experience. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  5. Early atmospheric metal pollution provides evidence for Chalcolithic/Bronze Age mining and metallurgy in Southwestern Europe

    Energy Technology Data Exchange (ETDEWEB)

    Martínez Cortizas, Antonio, E-mail: antonio.martinez.cortizas@usc.es [Departamento de Edafoloxía e Química Agrícola, Facultade de Bioloxía, Universidade de Santiago de Compostela, Campus Sur s/n, Santiago de Compostela (Spain); López-Merino, Lourdes, E-mail: lourdes.lopez-merino@brunel.ac.uk [Institute of Environment, Health and Societies, Brunel University London, UB8 3PH Uxbridge (United Kingdom); Bindler, Richard, E-mail: richard.bindler@umu.se [Department of Ecology and Environmental Science, Umeå University, Umeå (Sweden); Mighall, Tim, E-mail: t.mighall@abdn.ac.uk [Department of Geography & Environment, School of Geosciences, University of Aberdeen, Elphinstone Road, Aberdeen AB24 3UF (United Kingdom); Kylander, Malin E., E-mail: malin.kylander@geo.su.se [Department of Geological Sciences and the Bolin Centre for Climate Research, Stockholm University, SE-10691, Stockholm (Sweden)

    2016-03-01

    Although archaeological research suggests that mining/metallurgy already started in the Chalcolithic (3rd millennium BC), the earliest atmospheric metal pollution in SW Europe has thus far been dated to ~ 3500–3200 cal. yr. BP in paleo-environmental archives. A low intensity, non-extensive mining/metallurgy and the lack of appropriately located archives may be responsible for this mismatch. We have analysed the older section (> 2100 cal. yr. BP) of a peat record from La Molina (Asturias, Spain), a mire located in the proximity (35–100 km) of mines which were exploited in the Chalcolithic/Bronze Age, with the aim of assessing evidence of this early mining/metallurgy. Analyses included the determination of C as a proxy for organic matter content, lithogenic elements (Si, Al, Ti) as markers of mineral matter, and trace metals (Cr, Cu, Zn, Pb) and stable Pb isotopes as tracers of atmospheric metal pollution. From ~ 8000 to ~ 4980 cal. yr. BP the Pb composition is similar to that of the underlying sediments (Pb 15 ± 4 μg g{sup −1}; {sup 206}Pb/{sup 207}Pb 1.204 ± 0.002). A sustained period of low {sup 206}Pb/{sup 207}Pb ratios occurred from ~ 4980 to ~ 2470 cal. yr. BP, which can be divided into four phases: Chalcolithic (~ 4980–3700 cal. yr. BP), {sup 206}Pb/{sup 207}Pb ratios decline to 1.175 and Pb/Al ratios increase; Early Bronze Age (~ 3700–3500 cal. yr. BP), {sup 206}Pb/{sup 207}Pb increase to 1.192 and metal/Al ratios remain stable; Late Bronze Age (~ 3500–2800 cal. yr. BP), {sup 206}Pb/{sup 207}Pb decline to their lowest values (1.167) while Pb/Al and Zn/Al increase; and Early Iron Age (~ 2800–2470 cal. yr. BP), {sup 206}Pb/{sup 207}Pb increase to 1.186, most metal/Al ratios decrease but Zn/Al shows a peak. At the beginning of the Late Iron Age, {sup 206}Pb/{sup 207}Pb ratios and metal enrichments show a rapid return to pre-anthropogenic values. These results provide evidence of regional/local atmospheric metal pollution triggered by the

  6. Early atmospheric metal pollution provides evidence for Chalcolithic/Bronze Age mining and metallurgy in Southwestern Europe.

    Science.gov (United States)

    Martínez Cortizas, Antonio; López-Merino, Lourdes; Bindler, Richard; Mighall, Tim; Kylander, Malin E

    2016-03-01

    Although archaeological research suggests that mining/metallurgy already started in the Chalcolithic (3rd millennium BC), the earliest atmospheric metal pollution in SW Europe has thus far been dated to ~3500-3200 cal.yr. BP in paleo-environmental archives. A low intensity, non-extensive mining/metallurgy and the lack of appropriately located archives may be responsible for this mismatch. We have analysed the older section (>2100 cal.yr. BP) of a peat record from La Molina (Asturias, Spain), a mire located in the proximity (35-100 km) of mines which were exploited in the Chalcolithic/Bronze Age, with the aim of assessing evidence of this early mining/metallurgy. Analyses included the determination of C as a proxy for organic matter content, lithogenic elements (Si, Al, Ti) as markers of mineral matter, and trace metals (Cr, Cu, Zn, Pb) and stable Pb isotopes as tracers of atmospheric metal pollution. From ~8000 to ~4980 cal.yr. BP the Pb composition is similar to that of the underlying sediments (Pb 15 ± 4 μg g(-1); (206)Pb/(207)Pb 1.204 ± 0.002). A sustained period of low (206)Pb/(207)Pb ratios occurred from ~4980 to ~2470 cal.yr. BP, which can be divided into four phases: Chalcolithic (~4980-3700 cal.yr. BP), (206)Pb/(207)Pb ratios decline to 1.175 and Pb/Al ratios increase; Early Bronze Age (~3700-3500 cal.yr. BP), (206)Pb/(207)Pb increase to 1.192 and metal/Al ratios remain stable; Late Bronze Age (~3500-2800 cal.yr. BP), (206)Pb/(207)Pb decline to their lowest values (1.167) while Pb/Al and Zn/Al increase; and Early Iron Age (~2800-2470 cal.yr. BP), (206)Pb/(207)Pb increase to 1.186, most metal/Al ratios decrease but Zn/Al shows a peak. At the beginning of the Late Iron Age, (206)Pb/(207)Pb ratios and metal enrichments show a rapid return to pre-anthropogenic values. These results provide evidence of regional/local atmospheric metal pollution triggered by the earliest phases of mining/metallurgy in the area, and reconcile paleo-environmental and

  7. A case of early Wisconsinan ;over-chill;: New radiocarbon evidence for early extirpation of western camel (Camelops hesternus) in eastern Beringia

    Science.gov (United States)

    Zazula, Grant D.; MacPhee, Ross D. E.; Southon, John; Nalawade-Chavan, Shweta; Reyes, Alberto V.; Hewitson, Susan; Hall, Elizabeth

    2017-09-01

    There are comparatively few fossils that document the presence of the Pleistocene western camel (Camelops hesternus) in the unglaciated regions of Alaska and Yukon, northwestern North America (eastern Beringia). It has been previously reported on the basis of stratigraphic and radiocarbon data that this species was present within this region from the Sangamonian interglaciation (Marine Isotope Stage (MIS) 5) through the Last Glacial Maximum (LGM, MIS 2). However, the continued presence of western camel through the LGM is at odds with its ecological preferences as inferred from more southerly parts of the continent. Here we report 43 new radiocarbon dates on 34 western camel fossils from Alaska and Yukon, including specimens that have been dated previously. To minimize exogenous carbon contamination, we utilized either ultrafiltered collagen or single amino acid (hydroxyproline) methodologies in conducting the analyses. All samples, including previously reported specimens with finite ages, yielded ages that were either non-finite or close to the effective limit of radiocarbon dating. These results indicate that dates implying local presence of western camels in Alaska and Yukon during full-glacial conditions of MIS 2 are erroneous by as much as several tens of millennia, probably because of carbon contamination from glue or varnish used in fossil preparation and conservation. The revised radiocarbon chronology, together with other evidence, indicates that western camels were only able to occupy eastern Beringia only during Pleistocene interglaciations such as MIS 5, when forests and shrublands became the dominant regional biomes. The subsequent transition to cold, arid full-glacial conditions during the early Wisconsinan glaciation (MIS 4) around 75 000 years ago created unfavorable environmental conditions, eliminated browse, and led to their local extirpation in eastern Beringia. After their complete population loss in the Arctic and Subarctic, the range of

  8. Evidence for the prevention of bone loss in elderly and old early non-metastatic breast cancer patients treated with aromatase inhibitors

    DEFF Research Database (Denmark)

    Gunmalm, V.; Jørgensen, N. R.; Abrahamsen, B.

    2017-01-01

    Breast cancer (BC) is the most common cancer amongst women worldwide. Bone health is emerging as an important issue for BC survivors. In this literature study, we focus on agents for preventing bone loss in early non-metastatic estrogen receptor positive BC in treatment with aromatase inhibitors...... (AI) and to assess the evidence for antiresorptive treatment of bone loss in early non-metastatic breast cancer. We included randomized controlled trials (RCT's) comparing: (a) bisphosphonates and control; (b) different bisphosphonates; (c) denosumab and control and (d) bisphosphonates vs. denosumab...... in early non-metastatic BC women in AI treatment. Among antiresorptives, zoledronic acid currently has the highest evidence for prevention of AI associated bone loss in early non-metastatic BC. Data on fracture prevention among all patients, elderly and old is sparse. More randomized controlled studies...

  9. Preliminary evidence of early bone resorption in a sheep model of acute burn injury: an observational study.

    Science.gov (United States)

    Klein, Gordon L; Xie, Yixia; Qin, Yi-Xian; Lin, Liangjun; Hu, Minyi; Enkhbaatar, Perenlei; Bonewald, Lynda F

    2014-03-01

    Treatment with bisphosphonates within the first 10 days of severe burn injury completely prevents bone loss. We therefore postulated that bone resorption occurs early post burn and is the primary explanation for acute bone loss in these patients. Our objective was to assess bone for histological and biomechanical evidence of early resorption post burn. We designed a randomized controlled study utilizing a sheep model of burn injury. Three sheep received a 40 % total body surface area burn under isoflurane anesthesia, and three other sheep received cotton-smoke inhalation and served as control. Burned sheep were killed 5 days post procedure and controls were killed 2 days post procedure. Backscatter scanning electron microscopy was performed on iliac crests obtained immediately postmortem along with quantitative histomorphometry and compression testing to determine bone strength (Young's modulus). Blood ionized Ca was also determined in the first 24 h post procedure as was urinary CTx. Three of three sheep killed at 5 days had evidence of scalloping of the bone surface, an effect of bone resorption, whereas none of the three sheep killed at 2 days post procedure had scalloping. One of the three burned sheep killed at 5 days showed quantitative doubling of the eroded surface and halving of the bone volume compared to sham controls. Mean values of Young's modulus were approximately one third lower in the burned sheep killed at 5 days compared to controls, p = 0.08 by unpaired t test, suggesting weaker bone. These data suggest early post-burn bone resorption. Urine CTx normalized to creatinine did not differ between groups at 24 h post procedure because the large amounts of fluids received by the burned sheep may have diluted urine creatinine and CTx and because the urine volume produced by the burned sheep was threefold that of the controls. We calculated 24 h urinary CTx excretion, and with this calculation CTx excretion/24 h in the burned sheep was

  10. Outcomes and Impact of HIV Prevention, ART and TB Programs in Swaziland – Early Evidence from Public Health Triangulation

    Science.gov (United States)

    van Schalkwyk, Cari; Mndzebele, Sibongile; Hlophe, Thabo; Garcia Calleja, Jesus Maria; Korenromp, Eline L.; Stoneburner, Rand; Pervilhac, Cyril

    2013-01-01

    Introduction Swaziland’s severe HIV epidemic inspired an early national response since the late 1980s, and regular reporting of program outcomes since the onset of a national antiretroviral treatment (ART) program in 2004. We assessed effectiveness outcomes and mortality trends in relation to ART, HIV testing and counseling (HTC), tuberculosis (TB) and prevention of mother to child transmission (PMTCT). Methods Data triangulated include intervention coverage and outcomes according to program registries (2001-2010), hospital admissions and deaths disaggregated by age and sex (2001-2010) and population mortality estimates from the 1997 and 2007 censuses and the 2007 demographic and health survey. Results By 2010, ART reached 70% of the estimated number of people living with HIV/AIDS with CD4<350/mm3, with progressively improving patient retention and survival. As of 2010, 88% of health facilities providing antenatal care offered comprehensive PMTCT services. The HTC program recorded a halving in the proportion of adults tested who were HIV-infected; similarly HIV infection rates among HIV-exposed babies halved from 2007 to 2010. Case fatality rates among hospital patients diagnosed with HIV/AIDS started to decrease from 2005–6 in adults and especially in children, contrasting with stable case fatality for other causes including TB. All-cause child in-patient case fatality rates started to decrease from 2005–6. TB case notifications as well as rates of HIV/TB co-infection among notified TB patients continued a steady increase through 2010, while coverage of HIV testing and CPT for co-infected patients increased to above 80%. Conclusion Against a background of high, but stable HIV prevalence and decreasing HIV incidence, we documented early evidence of a mortality decline associated with the expanded national HIV response since 2004. Attribution of impact to specific interventions (versus natural epidemic dynamics) will require additional data from future

  11. When the waves of European Neolithization met: first paleogenetic evidence from early farmers in the southern Paris Basin.

    Directory of Open Access Journals (Sweden)

    Maïté Rivollat

    Full Text Available An intense debate concerning the nature and mode of Neolithic transition in Europe has long received much attention. Recent publications of paleogenetic analyses focusing on ancient European farmers from Central Europe or the Iberian Peninsula have greatly contributed to this debate, providing arguments in favor of major migrations accompanying European Neolithization and highlighting noticeable genetic differentiation between farmers associated with two archaeologically defined migration routes: the Danube valley and the Mediterranean Sea. The aim of the present study was to fill a gap with the first paleogenetic data of Neolithic settlers from a region (France where the two great currents came into both direct and indirect contact with each other. To this end, we analyzed the Gurgy 'Les Noisats' group, an Early/Middle Neolithic necropolis in the southern part of the Paris Basin. Interestingly, the archaeological record from this region highlighted a clear cultural influence from the Danubian cultural sphere but also notes exchanges with the Mediterranean cultural area. To unravel the processes implied in these cultural exchanges, we analyzed 102 individuals and obtained the largest Neolithic mitochondrial gene pool so far (39 HVS-I mitochondrial sequences and haplogroups for 55 individuals from a single archaeological site from the Early/Middle Neolithic period. Pairwise FST values, haplogroup frequencies and shared informative haplotypes were calculated and compared with ancient and modern European and Near Eastern populations. These descriptive analyses provided patterns resulting from different evolutionary scenarios; however, the archaeological data available for the region suggest that the Gurgy group was formed through equivalent genetic contributions of farmer descendants from the Danubian and Mediterranean Neolithization waves. However, these results, that would constitute the most ancient genetic evidence of admixture between farmers

  12. Early-Ming Era tsunami destruction along the Northern Coast of Aceh, Indonesia: New evidence from Archeology

    Science.gov (United States)

    Sieh, K.; Daly, P.; McKinnon, E. E.; Tai, Y. S.; Feener, R. M.; Ishmail, N.

    2017-12-01

    Our colleagues and we have reconstructed partial earthquake and tsunami histories along the coast of Aceh, Sumatra. Chlieh et al (2006) documented and modeled deformation of offshore islands associated with the 2004 rupture. Meltzner et al (2010) found coral evidence of uplifts in 1394±2 and 1450±3 CE. Sieh et al. (2015) documented associated tsunami that destroyed a structure built in 1366±3 CE, 40 km east of Banda Aceh at Lamreh. Since 2015, our landscape archaeology survey of 43 coastal villages over a 40-km reach of the coast has revealed 995 archaeological sites ranging from 10th century to present and containing over 5,000 carved gravestones and 50,000 ceramic sherds. The distribution of ceramic material suggests 7 discrete areas of cultural activity before the 1394 tsunami. Six of these appear to be villages that used imported ceramics and have been populated since the 10th century. However, detailed analysis indicates a clear reduction in activity between 1360 and 1450 CE. This suggests that one or both of the 1394 and 1450 tsunami disrupted the villages. The distribution of post-1500 CE ceramic material shows a gradual repopulation of pre-tsunami sites and a significant expansion of activity starting at the end of the 16th Century, for all areas except Lamreh. Only at on the elevated Lambaro highlands, above modern Lamreh, does material conclusively date between the 1394 and 1450 CE tsunamis. This historic trading site of "Lambri" contains large quantities of ceramics ranging from the early 11th century until the early 16th century, including precisely dated early-Ming (1403-1425 CE) material, some of which is distinctive imperial trade ceramics. We suspect that after the 1394 tsunami destroyed the other coastal settlements, the relatively safe highlands of Lambri were the only areas of the coast utilized for at least 50 years. After about 1450 CE, however, these highlands were abandoned, while the low-lying coastal communities began once again to

  13. A Clinical Translation of the Article Titled "Evidence for the Implementation of the Early Start Denver Model for Young Children With Autism Spectrum Disorder".

    Science.gov (United States)

    Shannon, Robin Adair

    2015-01-01

    The purpose of this article is to offer a clinical translation of a literature review titled "Evidence for the Implementation of the Early Start Denver Model for Young Children With Autism Spectrum Disorder" by Ryberg (2015). The literature review was conducted to determine the strength of the research evidence regarding the effectiveness of the Early Start Denver Model in improving cognitive, language, and behavioral functioning of children with autism spectrum disorder. In an effort to narrow the gap between evidence and practice, this clinical translation will discuss the components of the literature review in terms of its rationale for and objectives, methods, results, and implications for evidence-based nursing practice. © The Author(s) 2015.

  14. The Center for Response to Intervention in Early Childhood: Developing Evidence-Based Tools for a Multi-Tier Approach to Preschool Language and Early Literacy Instruction

    Science.gov (United States)

    Greenwood, Charles R.; Carta, Judith J.; Goldstein, Howard; Kaminski, Ruth A.; McConnell, Scott R.; Atwater, Jane

    2014-01-01

    The prevalence of struggling readers by third grade nationwide is estimated at one in three. Reports trace the roots of this problem to early childhood and the opportunity to learn language and early literacy skills at home and in preschool. Reports also indicate that one-size-fits-all preschool language and literacy instruction is beneficial for…

  15. Molecular evolution of glutamine synthetase II: Phylogenetic evidence of a non-endosymbiotic gene transfer event early in plant evolution

    Directory of Open Access Journals (Sweden)

    Tartar Aurélien

    2010-06-01

    Full Text Available Abstract Background Glutamine synthetase (GS is essential for ammonium assimilation and the biosynthesis of glutamine. The three GS gene families (GSI, GSII, and GSIII are represented in both prokaryotic and eukaryotic organisms. In this study, we examined the evolutionary relationship of GSII from eubacterial and eukaryotic lineages and present robust phylogenetic evidence that GSII was transferred from γ-Proteobacteria (Eubacteria to the Chloroplastida. Results GSII sequences were isolated from four species of green algae (Trebouxiophyceae, and additional green algal (Chlorophyceae and Prasinophytae and streptophyte (Charales, Desmidiales, Bryophyta, Marchantiophyta, Lycopodiophyta and Tracheophyta sequences were obtained from public databases. In Bayesian and maximum likelihood analyses, eubacterial (GSIIB and eukaryotic (GSIIE GSII sequences formed distinct clades. Both GSIIB and GSIIE were found in chlorophytes and early-diverging streptophytes. The GSIIB enzymes from these groups formed a well-supported sister clade with the γ-Proteobacteria, providing evidence that GSIIB in the Chloroplastida arose by horizontal gene transfer (HGT. Bayesian relaxed molecular clock analyses suggest that GSIIB and GSIIE coexisted for an extended period of time but it is unclear whether the proposed HGT happened prior to or after the divergence of the primary endosymbiotic lineages (the Archaeplastida. However, GSIIB genes have not been identified in glaucophytes or red algae, favoring the hypothesis that GSIIB was gained after the divergence of the primary endosymbiotic lineages. Duplicate copies of the GSIIB gene were present in Chlamydomonas reinhardtii, Volvox carteri f. nagariensis, and Physcomitrella patens. Both GSIIB proteins in C. reinhardtii and V. carteri f. nagariensis had N-terminal transit sequences, indicating they are targeted to the chloroplast or mitochondrion. In contrast, GSIIB proteins of P. patens lacked transit sequences, suggesting

  16. Numerical morphology supports early number word learning: Evidence from a comparison of young Mandarin and English learners

    Science.gov (United States)

    Corre, Mathieu Le; Li, Peggy; Huang, Becky H.; Jia, Gisela; Carey, Susan

    2016-01-01

    Previous studies showed that children learning a language with an obligatory singular/plural distinction (Russian and English) learn the meaning of the number word for one earlier than children learning Japanese, a language without obligatory number morphology (Barner, Libenson, Cheung, & Takasaki, 2009; Sarnecka, Kamenskaya, Yamana, Ogura, & Yudovina, 2007). This can be explained by differences in number morphology, but it can also be explained by many other differences between the languages and the environments of the children who were compared. The present study tests the hypothesis that the morphological singular/plural distinction supports the early acquisition of the meaning of the number word for one by comparing young English learners to age and SES matched young Mandarin Chinese learners. Mandarin does not have obligatory number morphology but is more similar to English than Japanese in many crucial respects. Corpus analyses show that, compared to English learners, Mandarin learners hear number words more frequently, are more likely to hear number words followed by a noun, and are more likely to hear number words in contexts where they denote a cardinal value. Two tasks show that, despite these advantages, Mandarin learners learn the meaning of the number word for one three to six months later than do English learners. These results provide the strongest evidence to date that prior knowledge of the numerical meaning of the distinction between singular and plural supports the acquisition of the meaning of the number word for one. PMID:27423486

  17. Challenges in knowledge translation: the early years of Cancer Care Ontario's Program in Evidence-Based Care.

    Science.gov (United States)

    Browman, G P

    2012-02-01

    Cancer Care Ontario's Program in Evidence-Based Care (pebc) was formalized in 1997 to produce clinical practice guidelines for cancer management for the Province of Ontario. At the time, the gap between guideline development and implementation was beginning to be acknowledged. The Program implemented strategies to promote use of guidelines. The program had to overcome numerous social challenges to survive. Prospective strategies useful to practitioners-including participation, transparent communication, a methodological vision, and methodology skills development offerings-were used to create a culture of research-informed oncology practice within a broad community of practitioners.Reactive strategies ensured the survival of the program in the early years, when some within the influential academic community and among decision-makers were skeptical about the feasibility of a rigorous methodologic approach meeting the fast turnaround times necessary for policy. The paper details the pebc strategies within the context of what was known about knowledge translation (kt) at the time, and it tries to identify key success factors. Many of the barriers faced in the implementation of kt-and the strategies for overcoming them-are unavailable in the public domain because the relevant reporting does not fit the traditional paradigm for publication. Telling the "stories behind the story" should be encouraged to enhance the practice of kt beyond the science.

  18. Community engagement to enhance child survival and early development in low- and middle-income countries: an evidence review.

    Science.gov (United States)

    Farnsworth, S Katherine; Böse, Kirsten; Fajobi, Olaoluwa; Souza, Patricia Portela; Peniston, Anne; Davidson, Leslie L; Griffiths, Marcia; Hodgins, Stephen

    2014-01-01

    As part of a broader evidence summit, USAID and UNICEF convened a literature review of effective means to empower communities to achieve behavioral and social changes to accelerate reductions in under-5 mortality and optimize early child development. The authors conducted a systematic review of the effectiveness of community mobilization and participation that led to behavioral change and one or more of the following: child health, survival, and development. The level and nature of community engagement was categorized using two internationally recognized models and only studies where the methods of community participation could be categorized as collaborative or shared leadership were eligible for analysis. The authors identified 34 documents from 18 countries that met the eligibility criteria. Studies with shared leadership typically used a comprehensive community action cycle, whereas studies characterized as collaborative showed clear emphasis on collective action but did not undergo an initial process of community dialogue. The review concluded that programs working collaboratively or achieving shared leadership with a community can lead to behavior change and cost-effective sustained transformation to improve critical health behaviors and reduce poor health outcomes in low- and middle-income countries. Overall, community engagement is an understudied component of improving child outcomes.

  19. Early evidence of xeromorphy in angiosperms: stomatal encryption in a new eocene species of Banksia (Proteaceae) from Western Australia.

    Science.gov (United States)

    Carpenter, Raymond J; McLoughlin, Stephen; Hill, Robert S; McNamara, Kenneth J; Jordan, Gregory John

    2014-09-01

    • Globally, the origins of xeromorphic traits in modern angiosperm lineages are obscure but are thought to be linked to the early Neogene onset of seasonally arid climates. Stomatal encryption is a xeromorphic trait that is prominent in Banksia, an archetypal genus centered in one of the world's most diverse ecosystems, the ancient infertile landscape of Mediterranean-climate southwestern Australia.• We describe Banksia paleocrypta, a sclerophyllous species with encrypted stomata from silcretes of the Walebing and Kojonup regions of southwestern Australia dated as Late Eocene.• Banksia paleocrypta shows evidence of foliar xeromorphy ∼20 Ma before the widely accepted timing for the onset of aridity in Australia. Species of Banksia subgenus Banksia with very similar leaves are extant in southwestern Australia. The conditions required for silcrete formation infer fluctuating water tables and climatic seasonality in southwestern Australia in the Eocene, and seasonality is supported by the paucity of angiosperm closed-forest elements among the fossil taxa preserved with B. paleocrypta. However, climates in the region during the Eocene are unlikely to have experienced seasons as hot and dry as present-day summers.• The presence of B. paleocrypta within the center of diversity of subgenus Banksia in edaphically ancient southwestern Australia is consistent with the continuous presence of this lineage in the region for ≥40 Ma, a testament to the success of increasingly xeromorphic traits in Banksia over an interval in which numerous other lineages became extinct. © 2014 Botanical Society of America, Inc.

  20. Numerical morphology supports early number word learning: Evidence from a comparison of young Mandarin and English learners.

    Science.gov (United States)

    Le Corre, Mathieu; Li, Peggy; Huang, Becky H; Jia, Gisela; Carey, Susan

    2016-08-01

    Previous studies showed that children learning a language with an obligatory singular/plural distinction (Russian and English) learn the meaning of the number word for one earlier than children learning Japanese, a language without obligatory number morphology (Barner, Libenson, Cheung, & Takasaki, 2009; Sarnecka, Kamenskaya, Yamana, Ogura, & Yudovina, 2007). This can be explained by differences in number morphology, but it can also be explained by many other differences between the languages and the environments of the children who were compared. The present study tests the hypothesis that the morphological singular/plural distinction supports the early acquisition of the meaning of the number word for one by comparing young English learners to age and SES matched young Mandarin Chinese learners. Mandarin does not have obligatory number morphology but is more similar to English than Japanese in many crucial respects. Corpus analyses show that, compared to English learners, Mandarin learners hear number words more frequently, are more likely to hear number words followed by a noun, and are more likely to hear number words in contexts where they denote a cardinal value. Two tasks show that, despite these advantages, Mandarin learners learn the meaning of the number word for one three to six months later than do English learners. These results provide the strongest evidence to date that prior knowledge of the numerical meaning of the distinction between singular and plural supports the acquisition of the meaning of the number word for one. Copyright © 2016. Published by Elsevier Inc.

  1. Earliest evidence for equid bit wear in the ancient Near East: The "ass" from Early Bronze Age Tell eṣ-Ṣâfi/Gath, Israel.

    Science.gov (United States)

    Greenfield, Haskel J; Shai, Itzhaq; Greenfield, Tina L; Arnold, Elizabeth R; Brown, Annie; Eliyahu, Adi; Maeir, Aren M

    2018-01-01

    Analysis of a sacrificed and interred domestic donkey from an Early Bronze Age (EB) IIIB (c. 2800-2600 BCE) domestic residential neighborhood at Tell eṣ-Ṣâfi/Gath, Israel, indicate the presence of bit wear on the Lower Premolar 2 (LPM2). This is the earliest evidence for the use of a bit among early domestic equids, and in particular donkeys, in the Near East. The mesial enamel surfaces on both the right and left LPM2 of the particular donkey in question are slightly worn in a fashion that suggests that a dental bit (metal, bone, wood, etc.) was used to control the animal. Given the secure chronological context of the burial (beneath the floor of an EB IIIB house), it is suggested that this animal provides the earliest evidence for the use of a bit on an early domestic equid from the Near East.

  2. Combined ERP/fMRI evidence for early word recognition effects in the posterior inferior temporal gyrus.

    Science.gov (United States)

    Dien, Joseph; Brian, Eric S; Molfese, Dennis L; Gold, Brian T

    2013-10-01

    Two brain regions with established roles in reading are the posterior middle temporal gyrus and the posterior fusiform gyrus (FG). Lesion studies have also suggested that the region located between them, the posterior inferior temporal gyrus (pITG), plays a central role in word recognition. However, these lesion results could reflect disconnection effects since neuroimaging studies have not reported consistent lexicality effects in pITG. Here we tested whether these reported pITG lesion effects are due to disconnection effects or not using parallel Event-related Potentials (ERP)/functional magnetic resonance imaging (fMRI) studies. We predicted that the Recognition Potential (RP), a left-lateralized ERP negativity that peaks at about 200-250 msec, might be the electrophysiological correlate of pITG activity and that conditions that evoke the RP (perceptual degradation) might therefore also evoke pITG activity. In Experiment 1, twenty-three participants performed a lexical decision task (temporally flanked by supraliminal masks) while having high-density 129-channel ERP data collected. In Experiment 2, a separate group of fifteen participants underwent the same task while having fMRI data collected in a 3T scanner. Examination of the ERP data suggested that a canonical RP effect was produced. The strongest corresponding effect in the fMRI data was in the vicinity of the pITG. In addition, results indicated stimulus-dependent functional connectivity between pITG and a region of the posterior FG near the Visual Word Form Area (VWFA) during word compared to nonword processing. These results provide convergent spatiotemporal evidence that the pITG contributes to early lexical access through interaction with the VWFA. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Metabolic profiling of CSF: evidence that early intervention may impact on disease progression and outcome in schizophrenia.

    Directory of Open Access Journals (Sweden)

    Elaine Holmes

    2006-08-01

    Full Text Available The identification of schizophrenia biomarkers is a crucial step towards improving current diagnosis, developing new presymptomatic treatments, identifying high-risk individuals and disease subgroups, and assessing the efficacy of preventative interventions at a rate that is not currently possible.(1H nuclear magnetic resonance spectroscopy in conjunction with computerized pattern recognition analysis were employed to investigate metabolic profiles of a total of 152 cerebrospinal fluid (CSF samples from drug-naïve or minimally treated patients with first-onset paranoid schizophrenia (referred to as "schizophrenia" in the following text and healthy controls. Partial least square discriminant analysis showed a highly significant separation of patients with first-onset schizophrenia away from healthy controls. Short-term treatment with antipsychotic medication resulted in a normalization of the disease signature in over half the patients, well before overt clinical improvement. No normalization was observed in patients in which treatment had not been initiated at first presentation, providing the first molecular evidence for the importance of early intervention for psychotic disorders. Furthermore, the alterations identified in drug-naïve patients could be validated in a test sample set achieving a sensitivity and specificity of 82% and 85%, respectively.Our findings suggest brain-specific alterations in glucoregulatory processes in the CSF of drug-naïve patients with first-onset schizophrenia, implying that these abnormalities are intrinsic to the disease, rather than a side effect of antipsychotic medication. Short-term treatment with atypical antipsychotic medication resulted in a normalization of the CSF disease signature in half the patients well before a clinical improvement would be expected. Furthermore, our results suggest that the initiation of antipsychotic treatment during a first psychotic episode may influence treatment response

  4. Using Evidence-Based Interventions to Improve Cancer Screening in the National Breast and Cervical Cancer Early Detection Program.

    Science.gov (United States)

    DeGroff, Amy; Carter, Aundrea; Kenney, Kristy; Myles, Zachary; Melillo, Stephanie; Royalty, Janet; Rice, Ketra; Gressard, Lindsay; Miller, Jacqueline W

    2016-01-01

    The National Breast and Cervical Cancer Early Detection Program (NBCCEDP) provides cancer screening to low-income, un-, and underinsured women through more than 11 000 primary care clinics. The program is well-positioned to work with health systems to implement evidence-based interventions (EBIs) to increase screening among all women. To collect baseline data on EBI use, evaluation of EBIs, and related training needs among NBCCEDP grantees. The Centers for Disease Control and Prevention conducted a Web-based survey in late 2013 among NBCCEDP grantees for the period July 2012 to June 2013. This was the first systematic assessment of EBIs among NBCCEDP grantees. The Centers for Disease Control and Prevention's NBCCEDP. Primarily program directors/coordinators for all 67 NBCCEDP grantees. Data captured were used to assess implementation of 5 EBIs, their evaluation, and related training needs. Frequencies and proportions were determined. Cluster analysis identified grantees with similar patterns of EBI use for NBCCEDP clients and providers. On average, 4.1 of 5 EBIs were implemented per grantee for NBCCEDP clients and providers. Four clusters were identified including "high overall EBI users," "high provider EBI users," "high EBI users with no provider assessment and feedback," and "high client EBI users." Only 1.8 EBIs were implemented, on average, with non-NBCCEDP clients and providers. Fewer than half (n = 32, 47.8%) of grantees conducted process or outcome evaluation of 1 or more EBIs. Overall, 47.6% of grantees reported high or medium training needs for client-oriented EBIs and 54.3% for provider-oriented EBIs. The NBCCEDP grantees are implementing EBIs extensively with clients and providers. Increased EBI use among non-NBCCEDP clients/providers is needed to extend the NBCCEDP's reach and impact. Grantee training and technical assistance is necessary across EBIs. In addition, grantees' use of process and outcome evaluation of EBI implementation must be increased

  5. Molecular genetic studies of natives on Easter Island: evidence of an early European and Amerindian contribution to the Polynesian gene pool.

    Science.gov (United States)

    Lie, B A; Dupuy, B M; Spurkland, A; Fernández-Viña, M A; Hagelberg, E; Thorsby, E

    2007-01-01

    Most archaeological and linguistic evidence suggest a Polynesian origin of the population of Easter Island (Rapanui), and this view has been supported by the identification of Polynesian mitochondrial DNA (mtDNA) polymorphisms in prehistoric skeletal remains. However, some evidence of an early South American contact also exists (the sweet potato, bottle gourd etc.), but genetic studies have so far failed to show an early Amerindian contribution to the gene pool on Easter Island. To address this issue, we analyzed mtDNA and Y chromosome markers and performed high-resolution human leukocyte antigen (HLA) genotyping of DNA harvested from previously collected sera of 48 reputedly nonadmixed native Easter Islanders. All individuals carried mtDNA types and HLA alleles previously found in Polynesia, and most men carried Y chromosome markers of Polynesian origin, providing further evidence of a Polynesian origin of the population of Easter Island. A few individuals carried HLA alleles and/or Y chromosome markers of European origin. More interestingly, some individuals carried the HLA alleles A*0212 and B*3905, which are of typical Amerindian origin. The genealogy of some of the individuals carrying these non-Polynesian HLA alleles and their haplotypic backgrounds suggest an introduction into Easter Island in the early 1800s, or earlier. Thus, there may have been an early European and Amerindian contribution to the Polynesian gene pool of Easter Island.

  6. Long-term forest dynamics at Gribskov, eastern Denmark with early-Holocene evidence for thermophilous broadleaved tree species

    DEFF Research Database (Denmark)

    Overballe-Petersen, Mette V; Nielsen, Anne Birgitte; Hannon, Gina E.

    2012-01-01

    two periods of the early Holocene and from c. 3000 cal. BP to present. The early-Holocene part of the record indicates a highly disturbed forest ecosystem with frequent fires and abundant macrofossils of particularly Betula sp. and Populus sp. The sediment stratigraphy and age–depth relationships give......We report on a full-Holocene pollen, charcoal and macrofossil record from a small forest hollow in Gribskov, eastern Denmark. The Fagus sylvatica pollen record suggests the establishment of a small Fagus population at Gribskov in the early Holocene together with early establishment of other...

  7. A randomized clinical trial of high-dosage coenzyme Q10 in early Parkinson disease: no evidence of benefit.

    Science.gov (United States)

    Beal, M Flint; Oakes, David; Shoulson, Ira; Henchcliffe, Claire; Galpern, Wendy R; Haas, Richard; Juncos, Jorge L; Nutt, John G; Voss, Tiffini Smith; Ravina, Bernard; Shults, Clifford M; Helles, Karen; Snively, Victoria; Lew, Mark F; Griebner, Brian; Watts, Arthur; Gao, Shan; Pourcher, Emmanuelle; Bond, Louisette; Kompoliti, Katie; Agarwal, Pinky; Sia, Cherissa; Jog, Mandar; Cole, Linda; Sultana, Munira; Kurlan, Roger; Richard, Irene; Deeley, Cheryl; Waters, Cheryl H; Figueroa, Angel; Arkun, Ani; Brodsky, Matthew; Ondo, William G; Hunter, Christine B; Jimenez-Shahed, Joohi; Palao, Alicia; Miyasaki, Janis M; So, Julie; Tetrud, James; Reys, Liza; Smith, Katharine; Singer, Carlos; Blenke, Anita; Russell, David S; Cotto, Candace; Friedman, Joseph H; Lannon, Margaret; Zhang, Lin; Drasby, Edward; Kumar, Rajeev; Subramanian, Thyagarajan; Ford, Donna Stuppy; Grimes, David A; Cote, Diane; Conway, Jennifer; Siderowf, Andrew D; Evatt, Marian Leslie; Sommerfeld, Barbara; Lieberman, Abraham N; Okun, Michael S; Rodriguez, Ramon L; Merritt, Stacy; Swartz, Camille Louise; Martin, W R Wayne; King, Pamela; Stover, Natividad; Guthrie, Stephanie; Watts, Ray L; Ahmed, Anwar; Fernandez, Hubert H; Winters, Adrienna; Mari, Zoltan; Dawson, Ted M; Dunlop, Becky; Feigin, Andrew S; Shannon, Barbara; Nirenberg, Melissa Jill; Ogg, Mattson; Ellias, Samuel A; Thomas, Cathi-Ann; Frei, Karen; Bodis-Wollner, Ivan; Glazman, Sofya; Mayer, Thomas; Hauser, Robert A; Pahwa, Rajesh; Langhammer, April; Ranawaya, Ranjit; Derwent, Lorelei; Sethi, Kapil D; Farrow, Buff; Prakash, Rajan; Litvan, Irene; Robinson, Annette; Sahay, Alok; Gartner, Maureen; Hinson, Vanessa K; Markind, Samuel; Pelikan, Melisa; Perlmutter, Joel S; Hartlein, Johanna; Molho, Eric; Evans, Sharon; Adler, Charles H; Duffy, Amy; Lind, Marlene; Elmer, Lawrence; Davis, Kathy; Spears, Julia; Wilson, Stephanie; Leehey, Maureen A; Hermanowicz, Neal; Niswonger, Shari; Shill, Holly A; Obradov, Sanja; Rajput, Alex; Cowper, Marilyn; Lessig, Stephanie; Song, David; Fontaine, Deborah; Zadikoff, Cindy; Williams, Karen; Blindauer, Karen A; Bergholte, Jo; Propsom, Clara Schindler; Stacy, Mark A; Field, Joanne; Mihaila, Dragos; Chilton, Mark; Uc, Ergun Y; Sieren, Jeri; Simon, David K; Kraics, Lauren; Silver, Althea; Boyd, James T; Hamill, Robert W; Ingvoldstad, Christopher; Young, Jennifer; Thomas, Karen; Kostyk, Sandra K; Wojcieszek, Joanne; Pfeiffer, Ronald F; Panisset, Michel; Beland, Monica; Reich, Stephen G; Cines, Michelle; Zappala, Nancy; Rivest, Jean; Zweig, Richard; Lumina, L Pepper; Hilliard, Colette Lynn; Grill, Stephen; Kellermann, Marye; Tuite, Paul; Rolandelli, Susan; Kang, Un Jung; Young, Joan; Rao, Jayaraman; Cook, Maureen M; Severt, Lawrence; Boyar, Karyn

    2014-05-01

    Coenzyme Q10 (CoQ10), an antioxidant that supports mitochondrial function, has been shown in preclinical Parkinson disease (PD) models to reduce the loss of dopamine neurons, and was safe and well tolerated in early-phase human studies. A previous phase II study suggested possible clinical benefit. To examine whether CoQ10 could slow disease progression in early PD. A phase III randomized, placebo-controlled, double-blind clinical trial at 67 North American sites consisting of participants 30 years of age or older who received a diagnosis of PD within 5 years and who had the following inclusion criteria: the presence of a rest tremor, bradykinesia, and rigidity; a modified Hoehn and Yahr stage of 2.5 or less; and no anticipated need for dopaminergic therapy within 3 months. Exclusion criteria included the use of any PD medication within 60 days, the use of any symptomatic PD medication for more than 90 days, atypical or drug-induced parkinsonism, a Unified Parkinson's Disease Rating Scale (UPDRS) rest tremor score of 3 or greater for any limb, a Mini-Mental State Examination score of 25 or less, a history of stroke, the use of certain supplements, and substantial recent exposure to CoQ10. Of 696 participants screened, 78 were found to be ineligible, and 18 declined participation. The remaining 600 participants were randomly assigned to receive placebo, 1200 mg/d of CoQ10, or 2400 mg/d of CoQ10; all participants received 1200 IU/d of vitamin E. Participants were observed for 16 months or until a disability requiring dopaminergic treatment. The prospectively defined primary outcome measure was the change in total UPDRS score (Parts I-III) from baseline to final visit. The study was powered to detect a 3-point difference between an active treatment and placebo. The baseline characteristics of the participants were well balanced, the mean age was 62.5 years, 66% of participants were male, and the mean baseline total UPDRS score was 22.7. A total of 267 participants

  8. Punctuated sediment discharge during early Pliocene birth of the Colorado River: Evidence from regional stratigraphy, sedimentology, and paleontology

    Science.gov (United States)

    Dorsey, Rebecca J.; O’Connell, Brennan; McDougall-Reid, Kristin; Homan, Mindy B.

    2018-01-01

    The Colorado River in the southwestern U.S. provides an excellent natural laboratory for studying the origins of a continent-scale river system, because deposits that formed prior to and during river initiation are well exposed in the lower river valley and nearby basinal sink. This paper presents a synthesis of regional stratigraphy, sedimentology, and micropaleontology from the southern Bouse Formation and similar-age deposits in the western Salton Trough, which we use to interpret processes that controlled the birth and early evolution of the Colorado River. The southern Bouse Formation is divided into three laterally persistent members: basal carbonate, siliciclastic, and upper bioclastic members. Basal carbonate accumulated in a tide-dominated marine embayment during a rise of relative sea level between ~ 6.3 and 5.4 Ma, prior to arrival of the Colorado River. The transition to green claystone records initial rapid influx of river water and its distal clay wash load into the subtidal marine embayment at ~ 5.4–5.3 Ma. This was followed by rapid southward progradation of the Colorado River delta, establishment of the earliest through-flowing river, and deposition of river-derived turbidites in the western Salton Trough (Wind Caves paleocanyon) between ~ 5.3 and 5.1 Ma. Early delta progradation was followed by regional shut-down of river sand output between ~ 5.1 and 4.8 Ma that resulted in deposition of marine clay in the Salton Trough, retreat of the delta, and re-flooding of the lower river valley by shallow marine water that deposited the Bouse upper bioclastic member. Resumption of sediment discharge at ~ 4.8 Ma drove massive progradation of fluvial-deltaic deposits back down the river valley into the northern Gulf and Salton Trough.These results provide evidence for a discontinuous, start-stop-start history of sand output during initiation of the Colorado River that is not predicted by existing models for this system. The underlying controls on

  9. Biotic and environmental dynamics through the Late Jurassic-Early Cretaceous transition: evidence for protracted faunal and ecological turnover.

    Science.gov (United States)

    Tennant, Jonathan P; Mannion, Philip D; Upchurch, Paul; Sutton, Mark D; Price, Gregory D

    2017-05-01

    The Late Jurassic to Early Cretaceous interval represents a time of environmental upheaval and cataclysmic events, combined with disruptions to terrestrial and marine ecosystems. Historically, the Jurassic/Cretaceous (J/K) boundary was classified as one of eight mass extinctions. However, more recent research has largely overturned this view, revealing a much more complex pattern of biotic and abiotic dynamics than has previously been appreciated. Here, we present a synthesis of our current knowledge of Late Jurassic-Early Cretaceous events, focusing particularly on events closest to the J/K boundary. We find evidence for a combination of short-term catastrophic events, large-scale tectonic processes and environmental perturbations, and major clade interactions that led to a seemingly dramatic faunal and ecological turnover in both the marine and terrestrial realms. This is coupled with a great reduction in global biodiversity which might in part be explained by poor sampling. Very few groups appear to have been entirely resilient to this J/K boundary 'event', which hints at a 'cascade model' of ecosystem changes driving faunal dynamics. Within terrestrial ecosystems, larger, more-specialised organisms, such as saurischian dinosaurs, appear to have suffered the most. Medium-sized tetanuran theropods declined, and were replaced by larger-bodied groups, and basal eusauropods were replaced by neosauropod faunas. The ascent of paravian theropods is emphasised by escalated competition with contemporary pterosaur groups, culminating in the explosive radiation of birds, although the timing of this is obfuscated by biases in sampling. Smaller, more ecologically diverse terrestrial non-archosaurs, such as lissamphibians and mammaliaforms, were comparatively resilient to extinctions, instead documenting the origination of many extant groups around the J/K boundary. In the marine realm, extinctions were focused on low-latitude, shallow marine shelf-dwelling faunas

  10. X-Ray Diffraction for In-Situ Mineralogical Analysis of Planetesimals.

    Science.gov (United States)

    Sarrazin, P.; Blake, D. F.; Dera, P.; Downs, R. T.; Taylor, J.

    2017-12-01

    X-ray diffraction (XRD) is a general purpose technique for definitive, quantitative mineralogical analysis. When combined with XRF data for sample chemistry, XRD analyses yield as complete a characterization as is possible by any spacecraft-capable techniques. The MSL CheMin instrument, the first XRD instrument flown in space, has been used to establish the quantitative mineralogy of the Mars global soil, to discover the first habitable environment on another planet, and to provide the first in-situ evidence of silicic volcanism on Mars. CheMin is now used to characterize the depositional and diagenetic environments associated with the mudstone sediments of lower strata of Mt. Sharp. Conventional powder XRD requires samples comprised of small grains presented in random orientations. In CheMin, sample cells are vibrated to cause loose powder to flow within the cell, driven by granular convection, which relaxes the requirement for fine grained samples. Nevertheless, CheMin still requires mechanisms to collect, crush, sieve and deliver samples before analysis. XTRA (Extraterrestrial Regolith Analyzer) is an evolution of CheMin intended to analyze fines in as-delivered surface regolith, without sample preparation. Fine-grained regolith coats the surfaces of most airless bodies in the solar system, and because this fraction is typically comminuted from the rocky regolith, it can often be used as a proxy for the surface as a whole. HXRD (Hybrid-XRD) is concept under development to analyze rocks or soils without sample preparation. Like in CheMin, the diffracted signal is collected with direct illumination CCD's. If the material is sufficiently fine-grained, a powder XRD pattern of the characteristic X-ray tube emission is obtained, similar to CheMin or XTRA. With coarse grained crystals, the white bremsstrahlung radiation of the tube is diffracted into Laue patterns. Unlike typical Laue applications, HXRD uses the CCD's capability to distinguish energy and analyze the

  11. Petrological and zircon evidence for the Early Cretaceous granulite-facies metamorphism in the Dabie orogen, China

    Science.gov (United States)

    Gao, Xiao-Ying; Zhang, Qiang-Qiang; Zheng, Yong-Fei; Chen, Yi-Xiang

    2017-07-01

    An integrated study of petrology, mineralogy, geochemistry, and geochronology was carried out for contemporaneous mafic granulite and diorite from the Dabie orogen. The results provide evidence for granulite-facies reworking of the ultrahigh-pressure (UHP) metamorphic rock in the collisional orogen. Most zircons from the granulite are new growth, and their U-Pb ages are clearly categorized into two groups at 122-127 Ma and 188 ± 2 Ma. Although these two groups of zircons show similarly steep HREE patterns and variably negative Eu anomalies, the younger group has much higher U, Th and REE contents and Th/U ratios, much lower εHf(t) values than the older group. This suggests their growth is associated with different types of dehydration reactions. The older zircon domains contain mineral inclusions of garnet + clinopyroxene ± quartz, indicating their growth through metamorphic reactions at high pressures. In contrast, the young zircon domains only contain a few quartz inclusions and the garnet-clinopyroxene-plagioclase-quartz barometry yields pressures of 4.9 to 12.5 kb. In addition, the clinopyroxene-garnet Fe-Mg exchange thermometry gives temperatures of 738-951 °C. Therefore, the young zircon domains would have grown through peritectic reaction at low to medium pressures. The younger granulite-facies metamorphic age is in agreement not only with the adjacent diorite at 125 ± 1 Ma in this study but also the voluminous emplacement of coeval mafic and felsic magmas in the Dabie orogen. Mineral separates from both mafic granulite and its adjacent diorite show uniformly lower δ18O values than normal mantle, similar to those for UHP eclogite-facies metaigneous rocks in the Dabie orogen. In combination with major-trace elements and zircon Lu-Hf isotope compositions, it is inferred that the protolith of mafic granulites shares with the source rock of diorites, both being a kind of mafic metasomatites at the slab-mantle interface in the continental subduction channel

  12. Subaqueous early eruptive phase of the late Aptian Rajmahal volcanism, India: Evidence from volcaniclastic rocks, bentonite, black shales, and oolite

    Directory of Open Access Journals (Sweden)

    Naresh C. Ghose

    2017-07-01

    Full Text Available The late Aptian (118–115 Ma continental flood basalts of the Rajmahal Volcanic Province (RVP are part of the Kerguelen Large Igneous Province, and constitute the uppermost part of the Gondwana Supergroup on the eastern Indian shield margin. The lower one-third of the Rajmahal volcanic succession contains thin layers of plant fossil-rich inter-trappean sedimentary rocks with pyroclasts, bentonite, grey and black shale/mudstone and oolite, whereas the upper two-thirds consist of sub-aerial fine-grained aphyric basalts with no inter-trappean material. At the eastern margin and the north-central sector of the RVP, the volcanics in the lower part include rhyolites and dacites overlain by enstatite-bearing basalts and enstatite-andesites. The pyroclastic rocks are largely felsic in composition, and comprise ignimbrite as well as coarse-grained tuff with lithic clasts, and tuff breccia with bombs, lapilli and ash that indicate explosive eruption of viscous rhyolitic magma. The rhyolites/dacites (>68 wt.% are separated from the andesites (<60 wt.% by a gap in silica content indicating their formation through upper crustal anatexis with only heat supplied by the basaltic magma. On the other hand, partially melted siltstone xenoliths in enstatite-bearing basalts suggest that the enstatite-andesites originated through mixing of the upper crust with basaltic magma, crystallizing orthopyroxene at a pressure-temperature of ∼3 kb/1150 °C. In contrast, the northwestern sector of the RVP is devoid of felsic-intermediate rocks, and the volcaniclastic rocks are predominantly mafic (basaltic in composition. Here, the presence of fine-grained tuffs, tuff breccia containing sideromelane shards and quenched texture, welded tuff breccia, peperite, shale/mudstone and oolite substantiates a subaqueous environment. Based on these observations, we conclude that the early phase of Rajmahal volcanism occurred under predominantly subaqueous conditions. The presence

  13. Clinically evident fat necrosis in women treated with high-dose-rate brachytherapy alone for early-stage breast cancer

    International Nuclear Information System (INIS)

    Wazer, David E.; Lowther, David; Boyle, Teresa; Ulin, Kenneth; Neuschatz, Andrew; Ruthazer, Robin; DiPetrillo, Thomas A.

    2001-01-01

    Purpose: To investigate the incidence of and variables associated with clinically evident fat necrosis in women treated on a protocol of high-dose-rate (HDR) brachytherapy alone without external-beam whole-breast irradiation for early-stage breast carcinoma. Methods and Materials: From 6/1997 until 8/1999, 30 women diagnosed with Stage I or II breast carcinoma underwent surgical excision and postoperative irradiation via HDR brachytherapy implant as part of a multi-institutional clinical Phase I/II protocol. Patients eligible included those with T1, T2, N0, N1 (≤3 nodes positive), M0 tumors of nonlobular histology with negative surgical margins, no extracapsular lymph-node extension, and a negative postexcision mammogram. Brachytherapy catheters were placed at the initial excision, re-excision, or at the time of axillary sampling. Direct visualization, surgical clips, ultrasound, or CT scans assisted in delineating the target volume defined as the excision cavity plus 2-cm margin. High activity 192 Ir (3-10 Ci) was used to deliver 340 cGy per fraction, 2 fractions per day, for 5 consecutive days to a total dose of 34 Gy to the target volume. Source position and dwell times were calculated using standard volume optimization techniques. Dosimetric analyses were performed with three-dimensional postimplant dose and volume reconstructions. The median follow-up of all patients was 24 months (range, 12-36 months). Results: Eight patients (crude incidence of 27%) developed clinically evident fat necrosis postimplant in the treated breast. Fat necrosis was determined by clinical presentation including pain and swelling in the treated volume, computed tomography, and/or biopsy. All symptomatic patients (7 of 8 cases) were successfully treated with 3 to 12 months of conservative management. Continuous variables that were found to be associated significantly with fat necrosis included the number of source dwell positions (p=0.04), and the volume of tissue which received

  14. Early to Middle Jurassic tectonic evolution of the Bogda Mountains, Northwest China: Evidence from sedimentology and detrital zircon geochronology

    Science.gov (United States)

    Ji, Hongjie; Tao, Huifei; Wang, Qi; Qiu, Zhen; Ma, Dongxu; Qiu, Junli; Liao, Peng

    2018-03-01

    The Bogda Mountains, as an important intracontinental orogenic belt, are situated in the southern part of the Central Asian Orogenic Belt (CAOB), and are a key area for understanding the Mesozoic evolution of the CAOB. However, the tectonic evolution of the Bogda Mountains remains controversial during the Mesozoic Era, especially the Early to Middle Jurassic Periods. The successive Lower to Middle Jurassic strata are well preserved and exposed along the northern flank of the Western Bogda Mountains and record the uplift processes of the Bogda Mountains. In this study, we analysed sedimentary facies combined with detrital zircon U-Pb geochronology at five sections of Lower to Middle Jurassic strata to detect the tectonic evolution and changes of provenance in the Bogda area. During Early to Middle Jurassic times, the fluvial, deltaic and lacustrine environments dominated in the western section of the Bogda area. The existence of Early Triassic peak age indicates that the Bogda Mountains did not experience uplift during the period of early Badaowan Formation deposition. The Early Triassic to Late Permian granitoid plutons and Carboniferous volcanic rocks from the Barkol and Santanghu areas were the main provenances. The significant change in the U-Pb age spectrum implies that the Eastern Bogda Mountains initiated uplift in the period of late Badaowan Formation deposition, and the Eastern Junggar Basin and the Turpan-Hami Basin were partially partitioned. The Eastern Bogda Mountains gradually became the major provenance. From the period of early Sangonghe to early Toutunhe Formations deposition, the provenance of the sediments and basin-range frame were similar to that of late Badaowan. However, the Eastern Bogda Mountains suffered intermittent uplift three times, and successive denudation. The uplifts respectively happened in early Sangonghe, late Sangonghe to early Xishanyao, and late Xishanyao to early Toutunhe. During the deposition stage of Toutunhe Formation, a

  15. Early life stress determines the effects of glucocorticoids and stress on hippocampal function: Electrophysiological and behavioral evidence respectively.

    Science.gov (United States)

    Pillai, Anup G; Arp, Marit; Velzing, Els; Lesuis, Sylvie L; Schmidt, Mathias V; Holsboer, Florian; Joëls, Marian; Krugers, Harm J

    2018-05-01

    Exposure to early-life adversity may program brain function to prepare individuals for adaptation to matching environmental contexts. In this study we tested this hypothesis in more detail by examining the effects of early-life stress - induced by raising offspring with limited nesting and bedding material from postnatal days 2-9 - in various behavioral tasks and on synaptic function in adult mice. Early-life stress impaired adult performance in the hippocampal dependent low-arousing object-in-context recognition memory task. This effect was absent when animals were exposed to a single stressor before training. Early-life stress did not alter high-arousing context and auditory fear conditioning. Early-life stress-induced behavioral modifications were not associated with alterations in the dendritic architecture of hippocampal CA1 pyramidal neurons or principal neurons of the basolateral amygdala. However, early-life stress reduced the ratio of NMDA to AMPA receptor-mediated excitatory postsynaptic currents and glutamate release probability specifically in hippocampal CA1 neurons, but not in the basolateral amygdala. These ex vivo effects in the hippocampus were abolished by acute glucocorticoid treatment. Our findings support that early-life stress can hamper object-in-context learning via pre- and postsynaptic mechanisms that affect hippocampal function but these effects are counteracted by acute stress or elevated glucocorticoid levels. Copyright © 2018. Published by Elsevier Ltd.

  16. Evidence of an IFN-γ by early life stress interaction in the regulation of amygdala reactivity to emotional stimuli.

    Science.gov (United States)

    Redlich, Ronny; Stacey, David; Opel, Nils; Grotegerd, Dominik; Dohm, Katharina; Kugel, Harald; Heindel, Walter; Arolt, Volker; Baune, Bernhard T; Dannlowski, Udo

    2015-12-01

    Since numerous studies have found that exposure to early life stress leads to increased peripheral inflammation and psychiatric disease, it is thought that peripheral immune activation precedes and possibly mediates the onset of stress-associated psychiatric disease. Despite early studies, IFNγ has received little attention relative to other inflammatory cytokines in the context of the pathophysiology of affective disorders. Neuroimaging endophenotypes have emerged recently as a promising means of elucidating these types of complex relationships including the modeling of the interaction between environmental factors and genetic predisposition. Here we investigate the GxE relationship between early-life stress and genetic variants of IFNγ on emotion processing. To investigate the impact of the relationship between genetic variants of IFNγ (rs1861494, rs2069718, rs2430561) and early life stress on emotion processing, a sample of healthy adults (n=409) undergoing an emotional faces paradigm in an fMRI study were genotyped and analysed. Information on early life stress was obtained via Childhood Trauma Questionnaire (CTQ). A positive association between early life stress and amygdala reactivity was found. Specifically, the main effect of genotype of rs1861494 on amygdala reactivity indicates a higher neural response in C allele carriers compared to T homozygotes, while we did not find main effects of rs2069718 and rs2430561. Importantly, interaction analyses revealed a specific interaction between IFNγ genotype (rs1861494) and early life stress affecting amygdala reactivity to emotional faces, resulting from a positive association between CTQ scores and amygdala reactivity in C allele carriers while this association was absent in T homozygotes. Our findings indicate that firstly the genetic variant of IFNγ (rs1861494) is involved with the regulation of amygdala reactivity to emotional stimuli and secondly, that this genetic variant moderates effects of early life

  17. Initial Clinician Reports of the Bottom-Up Dissemination of an Evidence-Based Intervention for Early Childhood Trauma

    Science.gov (United States)

    David, Paula; Schiff, Miriam

    2018-01-01

    Background: Bottom-up dissemination (BUD) of evidence based treatments (EBT), entailing the spread of an intervention through a peer network in a decentralized manner, is an under-reported phenomenon in the professional literature. Objective: This paper presents findings from a study researching the feasibility of BUD of an evidence-based…

  18. Links between white matter microstructure and cortisol reactivity to stress in early childhood: Evidence for moderation by parenting

    Directory of Open Access Journals (Sweden)

    Haroon I. Sheikh

    2014-01-01

    Full Text Available Activity of the hypothalamic–pituitary–adrenal axis (measured via cortisol reactivity may be a biological marker of risk for depression and anxiety, possibly even early in development. However, the structural neural correlates of early cortisol reactivity are not well known, although these would potentially inform broader models of mechanisms of risk, especially if the early environment further shapes these relationships. Therefore, we examined links between white matter architecture and young girls' cortisol reactivity and whether early caregiving moderated these links. We recruited 45 6-year-old girls based on whether they had previously shown high or low cortisol reactivity to a stress task at age 3. White matter integrity was assessed by calculating fractional anisotropy (FA of diffusion-weighted magnetic resonance imaging scans. Parenting styles were measured via a standardized parent–child interaction task. Significant associations were found between FA in white matter regions adjacent to the left thalamus, the right anterior cingulate cortex, and the right superior frontal gyrus (all ps < .001. Further, positive early caregiving moderated the effect of high cortisol reactivity on white matter FA (all ps ≤ .05, with high stress reactive girls who received greater parent positive affect showing white matter structure more similar to that of low stress reactive girls. Results show associations between white matter integrity of various limbic regions of the brain and early cortisol reactivity to stress and provide preliminary support for the notion that parenting may moderate associations.

  19. Early Silurian to Early Carboniferous ridge subduction in NW Junggar: Evidence from geochronological, geochemical, and Sr-Nd-Hf isotopic data on alkali granites and adakites

    Science.gov (United States)

    Zhang, Chen; Santosh, M.; Liu, Luofu; Luo, Qun; Zhang, Xin; Liu, Dongdong

    2018-02-01

    The Central Asian Orogenic Belt (CAOB) evolved through a long-lived orogeny involving multiple episodes of subduction and accretion marking a major phase of continental growth during the Paleozoic. The northern part of the Western Junggar region (NW Junggar) offers a window into these processes, particularly to constrain the timing of closure of the Paleo-Asian Ocean. Here we report geochemical, geochronological, and isotopic data from K-feldspar granites and adakitic rocks from the NW Junggar region. Zircon U-Pb ages suggest that the granites were emplaced during Early Silurian to the Early Carboniferous (434-328 Ma). The granites show geochemical characteristics similar to those of A-type granites, with high SiO2 (71.13-76.72 wt%), Na2O + K2O (8.00-9.59 wt%), and Al2O3 (12.28-14.08 wt%), but depleted Sr, Nb, Ta and Eu. They display moderate to high positive εNd(t) and εHf(t) values (4.26-8.21 and 7.69-14.60, respectively) and young Nd and Hf model ages (T2DM-Nd = 489-740 Ma and T2DM-Hf = 471-845 Ma), suggesting magma derivation through partial melting of lower crust in the Boshchekul-Chingiz and Zharma-Saur arcs. The adakites are characterized by high Sr content (406.5-751.6 ppm), and low Y (13.8-16.4 ppm) and Yb (1.5-1.8 ppm) content, yielding relatively high Sr/Y ratios (25.38-49.41) similar to those of modern adakites. They have high positive εNd(t) and εHf(t) values (7.85-8.25 and 13.23-15.97, respectively) and young Nd and Hf model ages (T2DM-Nd = 429-535 Ma and T2DM-Hf = 355-550 Ma), indicating that their source magmas were likely derived from partial melting of the oceanic crust beneath the Boshchekul-Chingiz arc. The petrogenesis and distribution of the A-type granites and adakites, as well as the tectonic architecture of the region, suggest that a ridge subduction event might have occurred during the Early Silurian to Early Carboniferous. In combination with previous studies in the Chinese Altai, we suggest a two-sided ridge subduction model for the

  20. Links between white matter microstructure and cortisol reactivity to stress in early childhood: evidence for moderation by parenting.

    Science.gov (United States)

    Sheikh, Haroon I; Joanisse, Marc F; Mackrell, Sarah M; Kryski, Katie R; Smith, Heather J; Singh, Shiva M; Hayden, Elizabeth P

    2014-01-01

    Activity of the hypothalamic-pituitary-adrenal axis (measured via cortisol reactivity) may be a biological marker of risk for depression and anxiety, possibly even early in development. However, the structural neural correlates of early cortisol reactivity are not well known, although these would potentially inform broader models of mechanisms of risk, especially if the early environment further shapes these relationships. Therefore, we examined links between white matter architecture and young girls' cortisol reactivity and whether early caregiving moderated these links. We recruited 45 6-year-old girls based on whether they had previously shown high or low cortisol reactivity to a stress task at age 3. White matter integrity was assessed by calculating fractional anisotropy (FA) of diffusion-weighted magnetic resonance imaging scans. Parenting styles were measured via a standardized parent-child interaction task. Significant associations were found between FA in white matter regions adjacent to the left thalamus, the right anterior cingulate cortex, and the right superior frontal gyrus (all ps parent positive affect showing white matter structure more similar to that of low stress reactive girls. Results show associations between white matter integrity of various limbic regions of the brain and early cortisol reactivity to stress and provide preliminary support for the notion that parenting may moderate associations.

  1. When the healthcare does not follow the evidence: The case of the lack of early intervention programs for psychosis in Spain.

    Science.gov (United States)

    Arango, Celso; Bernardo, Miguel; Bonet, Pere; Cabrera, Ana; Crespo-Facorro, Benedicto; Cuesta, Manuel J; González, Nel; Parrabera, Sílvia; Sanjuan, Julio; Serrano, Alfonso; Vieta, Eduard; Lennox, Belinda R; Melau, Marianne

    There is now sufficient evidence to support the importance of interventions in the early stages of psychosis. The delay in the detection and treatment of the first-episode psychosis is related to a lower and slower recovery, as well as a higher risk of relapse. Despite this fact, early intervention units or teams are still not regularly implemented in mental health service settings in Spain. In this opinion article, a review is presented of the main arguments for defending the need to implement these programs and strategies in order to achieve this aim. There are a number of programs for early intervention for psychosis currently working in other countries, with a therapeutic program that includes pharmacological and psychosocial interventions, together with public awareness, information dissemination, and family-professional collaboration activities. Published literature on the experience of these programs indicates that early intervention is not only effective in terms of the improvement of health status, but is also economically efficient. The main steps and recommendations needed to implement such early intervention programs in our country are described. Copyright © 2017 SEP y SEPB. All rights reserved.

  2. Confirmatory versus explorative endpoint analysis: Decision-making on the basis of evidence available from market authorization and early benefit assessment for oncology drugs.

    Science.gov (United States)

    Niehaus, Ines; Dintsios, Charalabos-Markos

    2018-03-26

    The early benefit assessment of pharmaceuticals in Germany and their preceding market authorization pursue different objectives. This is reflected by the inclusion of varying confirmatory endpoints within the evaluation of oncology drugs in early benefit assessment versus market authorization, with both relying on the same evidence. Data from assessments up to July 2015 are used to estimate the impact of explorative in comparison to confirmatory endpoints on market authorization and early benefit assessment by contrasting the benefit-risk ratio of EMA and the benefit-harm balance of the HTA jurisdiction. Agreement between market authorization and early benefit assessment is examined by Cohen's kappa (k). 21 of 41 assessments were considered in the analysis. Market authorization is more confirmatory than early benefit assessment because it includes a higher proportion of primary endpoints. The latter implies a primary endpoint to be relevant for the benefit-harm balance in only 67% of cases (0.078). Explorative mortality endpoints reached the highest agreement regarding the mutual consideration for the risk-benefit ratio and the benefit-harm balance (0.000). For explorative morbidity endpoints (-0.600), quality of life (-0.600) and side effects (-0.949) no agreement is ascertainable. To warrant a broader confirmatory basis for decisions supported by HTA, closer inter-institutional cooperation of approval authorities and HTA jurisdictions by means of reliable joint advice for manufacturers regarding endpoint definition would be favorable. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Do mental health problems in childhood predict chronic physical conditions among males in early adulthood? Evidence from a community-based prospective study.

    Science.gov (United States)

    Goodwin, R D; Sourander, A; Duarte, C S; Niemelä, S; Multimäki, P; Nikolakaros, G; Helenius, H; Piha, J; Kumpulainen, K; Moilanen, I; Tamminen, T; Almqvist, F

    2009-02-01

    Previous studies have documented associations between mental and physical health problems in cross-sectional studies, yet little is known about these relationships over time or the specificity of these associations. The aim of the current study was to examine the relationship between mental health problems in childhood at age 8 years and physical disorders in adulthood at ages 18-23 years. Multiple logistic regression analyses were used to examine the relationship between childhood mental health problems, reported by child, parent and teacher, and physical disorders diagnosed by a physician in early adulthood. Significant linkages emerged between childhood mental health problems and obesity, atopic eczema, epilepsy and asthma in early adulthood. Specifically, conduct problems in childhood were associated with a significantly increased likelihood of obesity and atopic eczema; emotional problems were associated with an increased likelihood of epilepsy and asthma; and depression symptoms at age 8 were associated with an increased risk of asthma in early adulthood. Our findings provide the first evidence of an association between mental health problems during childhood and increased risk of specific physical health problems, mainly asthma and obesity, during early adulthood, in a representative sample of males over time. These data suggest that behavioral and emotional problems in childhood may signal vulnerability to chronic physical health problems during early adulthood.

  4. The Long-Run Impacts of Early Childhood Education: Evidence from a Failed Policy Experiment. NBER Working Paper No. 17085

    Science.gov (United States)

    DeCicca, Philip; Smith, Justin D.

    2011-01-01

    We investigate short and long-term effects of early childhood education using variation created by a unique policy experiment in British Columbia, Canada. Our findings imply starting Kindergarten one year late substantially reduces the probability of repeating the third grade, and meaningfully increases in tenth grade math and reading scores.…

  5. Effectiveness of Early Entrepreneurship Education at the Primary School Level: Evidence from a Field Research in Morocco

    Science.gov (United States)

    Hassi, Abderrahman

    2016-01-01

    The present research is designed to identify the appropriate and relevant objectives that need to be pursued through entrepreneurial activities targeting elementary school children. It assesses the effectiveness of early entrepreneurship education. To do so, children aged 11 and 12 attended an entrepreneurial program and completed two versions of…

  6. Clay Mineralogy and Crystallinity as a Climatic Indicator: Evidence for Both Cold and Temperate Conditions on Early Mars

    Science.gov (United States)

    Horgan, B.; Rutledge, A.; Rampe, E. B.

    2015-01-01

    Surface weathering on Earth is driven by precipitation (rain/snow melt). Here we summarize the influence of climate on minerals produced during surface weathering, based on terrestrial literature and our new laboratory analyses of weathering products from glacial analog sites. By comparison to minerals identified in likely surface environments on Mars, we evaluate the implications for early martian climate.

  7. Reading Difficulties and Attention-Deficit/Hyperactivity Behaviours: Evidence of an Early Association in a Nonclinical Sample

    Science.gov (United States)

    Luoni, Chiara; Balottin, Umberto; Zaccagnino, Maria; Brembilla, Laura; Livetti, Giulia; Termine, Cristiano

    2015-01-01

    Attention-deficit/hyperactivity disorder (ADHD) often co-occurs with reading disability. A cross-sectional study in an Italian-speaking, nonclinical sample was conducted in an attempt to document the existence of an early association between reading difficulties (RD) and ADHD behaviours. We recruited a sample of 369 children in their first year at…

  8. Neighborhood Poverty Impacts Children's Physical Health and Well-Being over Time: Evidence from the Early Development Instrument

    Science.gov (United States)

    Cushon, Jennifer A.; Vu, Lan T. H.; Janzen, Bonnie L.; Muhajarine, Nazeem

    2011-01-01

    Research Findings: The purpose of this study was to investigate how neighborhoods and neighborhood socioeconomic disadvantage impact school readiness over time. School readiness was measured using the Early Development Instrument (EDI) for 3 populations of kindergartners in 2001, 2003, and 2005 in Saskatoon, Saskatchewan, Canada. EDI results…

  9. The Contribution of Short-Term Memory for Serial Order to Early Reading Acquisition: Evidence from a Longitudinal Study

    Science.gov (United States)

    Perez, Trecy Martinez; Majerus, Steve; Poncelet, Martine

    2012-01-01

    Early reading acquisition skills have been linked to verbal short-term memory (STM) capacity. However, the nature of this relationship remains controversial because verbal STM, like reading acquisition, depends on the complexity of underlying phonological processing skills. This longitudinal study addressed the relation between STM and reading…

  10. Further Evidence for the Role of Pregnancy-induced Hypertension and Other Early Life Influences in the Development of ADHD

    DEFF Research Database (Denmark)

    Pohlabeln, Hermann; Rach, Stefan; De Henauw, Stefaan

    2017-01-01

    The aim of this study is to investigate whether in addition to established early risk factors other, less studied pre-, peri-, and postnatal influences, like gestational hypertension or neonatal respiratory disorders and infections, may increase a child’s risk of developing attention-deficit/hype...

  11. The impact of early retirement incentives on labor market participation: evidence from a parametric change in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Kocourek, D.; Pertold, Filip

    2011-01-01

    Roč. 61, č. 5 (2011), s. 467-483 ISSN 0015-1920 R&D Projects: GA MŠk LC542 Institutional research plan: CEZ:AV0Z70850503 Keywords : early retirement * labor market participation * Czech Republic Subject RIV: AH - Economics Impact factor: 0.346, year: 2011 http://journal.fsv.cuni.cz/storage/1226_kocourek.pdf

  12. Early user involvement and participation in employee self-service application deployment: theory and evidence from four Dutch governmental cases.

    NARCIS (Netherlands)

    Koopman, G.; Batenburg, R.

    2009-01-01

    This paper theoretically and empirically addresses the notion that user participation and involvement is one of the important factors for IS success. Different models and studies are reviewed to define and classify types of early end-user involvement and participation. Next, five case studies are

  13. Haptic orientation perception benefits from visual experience : Evidence from early-blind, late-blind, and sighted people

    NARCIS (Netherlands)

    Postma, Albert; Zuidhoek, Sander; Noordzij, Matthijs L.; Kappers, A. M L

    2008-01-01

    Early-blind, late-blind, and blindfolded sighted participants were presented with two haptic allocentric spatial tasks: a parallel-setting task, in an immediate and a 10-sec delay condition, and a task in which the orientation of a single bar was judged verbally. With respect to deviation size, the

  14. Mineralogical evidence of reduced East Asian summer monsoon rainfall on the Chinese loess plateau during the early Pleistocene interglacials

    Science.gov (United States)

    Meng, Xianqiang; Liu, Lianwen; Wang, Xingchen T.; Balsam, William; Chen, Jun; Ji, Junfeng

    2018-03-01

    The East Asian summer monsoon (EASM) is an important component of the global climate system. A better understanding of EASM rainfall variability in the past can help constrain climate models and better predict the response of EASM to ongoing global warming. The warm early Pleistocene, a potential analog of future climate, is an important period to study EASM dynamics. However, existing monsoon proxies for reconstruction of EASM rainfall during the early Pleistocene fail to disentangle monsoon rainfall changes from temperature variations, complicating the comparison of these monsoon records with climate models. Here, we present three 2.6 million-year-long EASM rainfall records from the Chinese Loess Plateau (CLP) based on carbonate dissolution, a novel proxy for rainfall intensity. These records show that the interglacial rainfall on the CLP was lower during the early Pleistocene and then gradually increased with global cooling during the middle and late Pleistocene. These results are contrary to previous suggestions that a warmer climate leads to higher monsoon rainfall on tectonic timescales. We propose that the lower interglacial EASM rainfall during the early Pleistocene was caused by reduced sea surface temperature gradients across the equatorial Pacific, providing a testable hypothesis for climate models.

  15. Hf and Nd Isotope Evidence for Production of an Incompatible Trace Element Enriched Crustal Reservoir in Early Earth (Invited)

    Science.gov (United States)

    Brandon, A. D.; Debaille, V.; Lapen, T. J.

    2010-12-01

    The final significant stage of accretion of the Earth was likely a collision between proto-Earth and a Mars sized impactor that formed the Moon. This event is thought to have produced enough thermal energy to melt all or most of the Earth, with a consequent magma ocean (MO). During subsequent cooling, the Earth would have formed its protocrust and corresponding mantle lithosphere, consisting of solidified basalt-komatiitic melt, in combination with buoyant cumulates and late stage residual melts from the MO. Relative to the convecting mantle, portions of this protolithosphere are likely to have been enriched in incompatible trace elements (ITE) in sufficient quantities to contain a significant amount of the bulk Earth’s budget for rare earth elements, U, Th, and Hf. If the protolithosphere was negatively buoyant, it may have overturned at or near the final stages of MO crystallization and a significant portion of that material may have been transported into the deep mantle where it resided and remixed into the convecting mantle over Earth history [1,2]. If the protolithosphere remained positively buoyant, its crust would have likely begun to erode from surface processes, and subsequently recycled back into the mantle over time as sediment and altered crust, once a subduction mechanism arose. The Nd and Hf isotopic compositions of Earth’s earliest rocks support the idea that an early-formed ITE-enriched reservoir was produced. The maxima in 142Nd/144Nd for 3.85 to 3.64 Ga rocks from Isua, Greenland decreases from +20 ppm to +12 ppm relative to the present day mantle value, respectively [3]. This indicates mixing of an early-formed ITE enriched reservoir back into the convecting mantle. In addition, zircons from the 3.1 Ga Jack Hills conglomerate indicate that material with an enriched 176Lu/177Hf of ~0.02 and an age of 4.4 Ga or greater was present at the Earth’s surface over the first 2 Ga of Earth history, supporting the scenario of a positively buoyant

  16. Association Between Low IQ Scores and Early Mortality in Men and Women: Evidence From a Population-Based Cohort Study.

    Science.gov (United States)

    Maenner, Matthew J; Greenberg, Jan S; Mailick, Marsha R

    2015-05-01

    Lower (versus higher) IQ scores have been shown to increase the risk of early mortality, however, the underlying mechanisms are poorly understood and previous studies underrepresent individuals with intellectual disability (ID) and women. This study followed one third of all senior-year students (approximately aged 17) attending public high school in Wisconsin, U.S. in 1957 (n  =  10,317) until 2011. Men and women with the lowest IQ test scores (i.e., IQ scores ≤ 85) had increased rates of mortality compared to people with the highest IQ test scores, particularly for cardiovascular disease. Importantly, when educational attainment was held constant, people with lower IQ test scores did not have higher mortality by age 70 than people with higher IQ test scores. Individuals with lower IQ test scores likely experience multiple disadvantages throughout life that contribute to increased risk of early mortality.

  17. Evidence for a constant IMF in early-type galaxies based on their X-ray binary populations

    OpenAIRE

    Peacock, Mark B.; Zepf, Stephen E.; Maccarone, Thomas J.; Kundu, Arunav; Gonzalez, Anthony H.; Lehmer, Bret D.; Maraston, Claudia

    2014-01-01

    A number of recent studies have proposed that the stellar initial mass function (IMF) of early type galaxies varies systematically as a function of galaxy mass, with higher mass galaxies having bottom heavy IMFs. These bottom heavy IMFs have more low-mass stars relative to the number of high mass stars, and therefore naturally result in proportionally fewer neutron stars and black holes. In this paper, we specifically predict the variation in the number of black holes and neutron stars based ...

  18. Associations between birth registration and early child growth and development: evidence from 31 low- and middle-income countries.

    Science.gov (United States)

    Jeong, Joshua; Bhatia, Amiya; Fink, Günther

    2018-05-30

    Lack of legal identification documents can impose major challenges for children in low- and middle-income countries (LMICs). The aim of this study was to investigate the association between not having a birth certificate and young children's physical growth and developmental outcomes in LMICs. We combined nationally representative data from the Multiple Indicator Cluster Surveys in 31 LMICs. For our measure of birth registration, primary caregivers reported on whether the child had a birth certificate. Early child outcome measures focused on height-for-age z-scores (HAZ), weight-for-age z-scores (WAZ), weight-for-height z-scores (WHZ), and standardized scores of the Early Childhood Development Index (ECDI) for a subsample of children aged 36-59 months. We used linear regression models with country fixed effects to estimate the relationship between birth registration and child outcomes. In fully adjusted models, we controlled for a variety of child, caregiver, household, and access to child services covariates, including cluster-level fixed effects. In the total sample, 34.7% of children aged 0-59 months did not possess a birth certificate. After controlling for covariates, not owning a birth certificate was associated with lower HAZ (β = - 0.18; 95% CI: -0.23, - 0.14), WAZ (β = - 0.10, 95% CI: -0.13, - 0.07), and ECDI z-scores (β = - 0.10; 95% CI: -0.13, - 0.07) among children aged 36-59 months. Our findings document links between birth registration and children's early growth and development outcomes. Efforts to increase birth registration may be promising for promoting early childhood development in LMICs.

  19. Scientific Reasoning in Early and Middle Childhood: The Development of Domain-General Evidence Evaluation, Experimentation, and Hypothesis Generation Skills

    Science.gov (United States)

    Piekny, Jeanette; Maehler, Claudia

    2013-01-01

    According to Klahr's (2000, 2005; Klahr & Dunbar, 1988) Scientific Discovery as Dual Search model, inquiry processes require three cognitive components: hypothesis generation, experimentation, and evidence evaluation. The aim of the present study was to investigate (a) when the ability to evaluate perfect covariation, imperfect covariation,…

  20. Scientific reasoning in early and middle childhood: the development of domain-general evidence evaluation, experimentation, and hypothesis generation skills.

    Science.gov (United States)

    Piekny, Jeanette; Maehler, Claudia

    2013-06-01

    According to Klahr's (2000, 2005; Klahr & Dunbar, 1988) Scientific Discovery as Dual Search model, inquiry processes require three cognitive components: hypothesis generation, experimentation, and evidence evaluation. The aim of the present study was to investigate (a) when the ability to evaluate perfect covariation, imperfect covariation, and non-covariation evidence emerges, (b) when experimentation emerges, (c) when hypothesis generation skills emerge, and (d), whether these abilities develop synchronously during childhood. We administered three scientific reasoning tasks referring to the three components to 223 children of five age groups (from age 4.0 to 13.5 years). Our results show that the three cognitive components of domain-general scientific reasoning emerge asynchronously. The development of domain-general scientific reasoning begins with the ability to handle unambiguous data, progresses to the interpretation of ambiguous data, and leads to a flexible adaptation of hypotheses according to the sufficiency of evidence. When children understand the relation between the level of ambiguity of evidence and the level of confidence in hypotheses, the ability to differentiate conclusive from inconclusive experiments accompanies this development. Implications of these results for designing science education concepts for young children are briefly discussed. © 2012 The British Psychological Society.

  1. Prospective Links between Friendship and Early Physical Aggression: Preliminary Evidence Supporting the Role of Friendship Quality through a Dyadic Intervention

    Science.gov (United States)

    Salvas, Marie-Claude; Vitaro, Frank; Brendgen, Mara; Cantin, Ste´phane

    2016-01-01

    Positive friendships have been related to decreasing levels of children's physical aggression over time. While this evidence calls for interventions aimed at helping children build good-quality friendships, tests of causality through experimental manipulations are still needed. The goal of this study was to examine whether an intervention aimed to…

  2. Ecosystem change during MIS4 and early MIS 3: Evidence from Middle Stone Age sites in South Africa

    CSIR Research Space (South Africa)

    Hall, G

    2010-11-01

    Full Text Available Several Middle Stone Age (MSA) site in southern Africa present evidence of environmental changes during Marine Isotope Stages (MIS) 4 and 3 between 70ka and 50ka. Of these, Sibudu Cave, KwaZulu-Natal, has yielded a detailed record of how globalscale...

  3. Evidence for Different Disk Mass Distributions between Early- and Late-type Be Stars in the BeSOS Survey

    Energy Technology Data Exchange (ETDEWEB)

    Arcos, C.; Kanaan, S.; Curé, M. [Instituto de Física y Astronomía, Facultad de Ciencias, Universidad de Valparaíso. Av. Gran Bretana 1111, Valparaíso (Chile); Jones, C. E.; Sigut, T. A. A. [Department of Physics and Astronomy, The University of Western Ontario, London, ON N6A 3K7 (Canada)

    2017-06-10

    The circumstellar disk density distributions for a sample of 63 Be southern stars from the BeSOS survey were found by modeling their H α emission line profiles. These disk densities were used to compute disk masses and disk angular momenta for the sample. Average values for the disk mass are 3.4 × 10{sup −9} and 9.5 × 10{sup −10} M {sub ⋆} for early (B0–B3) and late (B4–B9) spectral types, respectively. We also find that the range of disk angular momentum relative to the star is (150–200) J {sub ⋆}/ M {sub ⋆} and (100–150) J {sub ⋆}/ M {sub ⋆}, again for early- and late-type Be stars, respectively. The distributions of the disk mass and disk angular momentum are different between early- and late-type Be stars at a 1% level of significance. Finally, we construct the disk mass distribution for the BeSOS sample as a function of spectral type and compare it to the predictions of stellar evolutionary models with rapid rotation. The observed disk masses are typically larger than the theoretical predictions, although the observed spread in disk masses is typically large.

  4. Does an early socialization into a food culture condition lifelong food preferences? Evidence from a retrospective study.

    Science.gov (United States)

    Scrob, Mircea-Lucian

    2016-06-01

    The influence of early formed dietary practices on food choices and preferences during adulthood has often been assumed but rarely adequately demonstrated given the difficulty of studying the subject matter with conventional laboratory or observational research designs. This article examines this assumption by analyzing the information from 31 structured interviews on the respondents' current preferences for combinations of six side dishes with bread or mămăligă (boiled cornmeal mush, similar to polenta). All the respondents had consumed mămăligă in their childhood but in their adulthood had switched to bread following the social and economic upheavals from 1960s Romania. The results show that a) for specific combinations, physiological factors and/or cultural norms that defined bread as a 'prestigious' food have been capable of overriding the effects of early socialization with mămăligă as the accompanying food and b) that consumers continue to prefer certain side dishes with mămăligă even after decades of predominant consumption of bread although confounding factors might account for such preferences. These findings qualify the expectation that an early familiarization with healthy eating habits will promote this desired lifestyle during adulthood by showing that physiological and socio-cultural factors are capable of overriding its effects on hedonic preferences. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Tikal, Guatemala, and Emergent Maya Civilization: Excavations reveal evidence of early complex-living at a prime Maya Indian site.

    Science.gov (United States)

    Coe, W R

    1965-03-19

    It would be extravagant to claim that these pages have outlined meaningfully the early evolution of Tikal. Data have been provided largely for one excavation locus at a site which, for all its importance, merely has symptomatic value. We cannot claim to have, at present, sufficient material to document satisfyingly the conditions and products of community-wide living at any point in these early times. Present knowledge of Eb and Tzec ceramics and of all the usual archeological correlates (architecture and so on) is disturbingly incomplete. While we do have a good many data on residence throughout much of Preclassic time, considerably more information is needed before a solid evaluation of Preclassic Tikal society can be achieved. One can only hope that pending excavation programs will provide it. Yet, experience shows that probably only a tiny percentage of early cultural remains, regardless of their grandeur and importance at the time, would have survived the constant quest for construction fills to satisfy a seemingly interminable need to build and revamp.

  6. Older adults benefit from music training early in life: biological evidence for long-term training-driven plasticity.

    Science.gov (United States)

    White-Schwoch, Travis; Woodruff Carr, Kali; Anderson, Samira; Strait, Dana L; Kraus, Nina

    2013-11-06

    Aging results in pervasive declines in nervous system function. In the auditory system, these declines include neural timing delays in response to fast-changing speech elements; this causes older adults to experience difficulty understanding speech, especially in challenging listening environments. These age-related declines are not inevitable, however: older adults with a lifetime of music training do not exhibit neural timing delays. Yet many people play an instrument for a few years without making a lifelong commitment. Here, we examined neural timing in a group of human older adults who had nominal amounts of music training early in life, but who had not played an instrument for decades. We found that a moderate amount (4-14 years) of music training early in life is associated with faster neural timing in response to speech later in life, long after training stopped (>40 years). We suggest that early music training sets the stage for subsequent interactions with sound. These experiences may interact over time to sustain sharpened neural processing in central auditory nuclei well into older age.

  7. Heritable influences on behavioural problems from early childhood to mid-adolescence: evidence for genetic stability and innovation.

    Science.gov (United States)

    Lewis, G J; Plomin, R

    2015-07-01

    Although behavioural problems (e.g., anxiety, conduct, hyperactivity, peer problems) are known to be heritable both in early childhood and in adolescence, limited work has examined prediction across these ages, and none using a genetically informative sample. We examined, first, whether parental ratings of behavioural problems (indexed by the Strengths and Difficulties questionnaire) at ages 4, 7, 9, 12, and 16 years were stable across these ages. Second, we examined the extent to which stability reflected genetic or environmental effects through multivariate quantitative genetic analysis on data from a large (n > 3000) population (UK) sample of monozygotic and dizygotic twins. Behavioural problems in early childhood (age 4 years) showed significant associations with the corresponding behavioural problem at all subsequent ages. Moreover, stable genetic influences were observed across ages, indicating that biological bases underlying behavioural problems in adolescence are underpinned by genetic influences expressed as early as age 4 years. However, genetic and environmental innovations were also observed at each age. These observations indicate that genetic factors are important for understanding stable individual differences in behavioural problems across childhood and adolescence, although novel genetic influences also facilitate change in such behaviours.

  8. Rapid growth in early childhood associated with young adult overweight and obesity--evidence from a community based cohort study.

    Science.gov (United States)

    Sutharsan, Ratneswary; O'Callaghan, Michael J; Williams, Gail; Najman, Jake M; Mamun, Abdullah A

    2015-08-08

    Rapid weight gain in early life may increase the risk of overweight and obesity in adulthood. We investigated the association between the rate of growth during early childhood and the development of overweight and obesity in young adults. We used a prospective cohort study of 2077 young adults who were born between 1981 and 1984 in Brisbane, Australia and had anthropometry measurements available at birth, 6 months, 5 years, 14 years and 21 years of age. The associations of rate of early growth with body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) and their categories at 21 years were studied using multivariate analysis. We found that rapid weight gain [> + 0.67 standard deviation score (SDS)] in the first 5 years of life was associated with young adults' overweight status (BMI: adjusted OR = 2.35, 95% CI, 1.82-3.03; WC: adjusted OR = 2.20, 95% CI, 1.65-2.95). We also observed that slow weight gain in the first 5 years of age (young adulthood, in contrast slow weight gain was inversely associated with weight status at 21 years.

  9. Toward Primary Prevention of Asthma. Reviewing the Evidence for Early-Life Respiratory Viral Infections as Modifiable Risk Factors to Prevent Childhood Asthma

    Science.gov (United States)

    Feldman, Amy S.; He, Yuan; Moore, Martin L.; Hershenson, Marc B.

    2015-01-01

    A first step in primary disease prevention is identifying common, modifiable risk factors that contribute to a significant proportion of disease development. Infant respiratory viral infection and childhood asthma are the most common acute and chronic diseases of childhood, respectively. Common clinical features and links between these diseases have long been recognized, with early-life respiratory syncytial virus (RSV) and rhinovirus (RV) lower respiratory tract infections (LRTIs) being strongly associated with increased asthma risk. However, there has long been debate over the role of these respiratory viruses in asthma inception. In this article, we systematically review the evidence linking early-life RSV and RV LRTIs with asthma inception and whether they could therefore be targets for primary prevention efforts. PMID:25369458

  10. The contribution of Australian residential early parenting centres to comprehensive mental health care for mothers of infants: evidence from a prospective study

    Directory of Open Access Journals (Sweden)

    Fisher Jane RW

    2010-04-01

    Full Text Available Abstract Background Australia's public access residential early parenting services provide programs to assist parents who self-refer, to care for their infants and young children. Treatment programs target infant feeding and sleeping difficulties and maternal mental health. There is limited systematic evidence of maternal and infant mental health, psychosocial circumstances or presenting problems, or the effectiveness of the programs. The aim of this study was to contribute to the evidence base about residential early parenting services. Methods A prospective cohort design was used. A consecutive sample of mothers with infants under one year old recruited during admission to a public access residential early parenting service for a 4 or 5 night stay in Melbourne, Australia was recruited. They completed structured self-report questionnaires, incorporating standardised measures of infant behaviour and maternal mood, during admission and at one and six months after discharge. Changes in infant behaviour and maternal psychological functioning after discharge were observed. Results 79 women completed the first questionnaire during admission, and 58 provided complete data. Women admitted to the residential program have poor physical and mental health, limited family support, and infants with substantial behaviour difficulties. One month after discharge significant improvements in infant behaviour and maternal psychological functioning were observed (mean (SD daily crying and fussing during admission = 101.02 (100.8 minutes reduced to 37.7 (55.2 at one month post discharge, p Conclusions This psycho-educational approach is an effective and acceptable early intervention for parenting difficulties and maternal mood disturbance, and contributes to a system of comprehensive mental health care for mothers of infants.

  11. 'Holding the line': a qualitative study of the role of evidence in early phase decision-making in the reconfiguration of stroke services in London.

    Science.gov (United States)

    Fraser, Alec; Baeza, Juan I; Boaz, Annette

    2017-06-09

    Health service reconfigurations are of international interest but remain poorly understood. This article focuses on the use of evidence by senior managerial decision-makers involved in the reconfiguration of stroke services in London 2008-2012. Recent work comparing stroke service reconfiguration in London and Manchester emphasises the ability of senior managerial decision-makers in London to 'hold the line' in the crucial early phases of the stroke reconfiguration programme. In this article, we explore in detail how these decision-makers 'held the line' and ask what the broader power implications of doing so are for the interaction between evidence, health policy and system redesign. The research combined semi-structured interviews (n = 20) and documentary analysis of historically relevant policy papers and contemporary stroke reconfiguration documentation published by NHS London and other interested parties (n = 125). We applied a critical interpretive and reflexive approach to the analysis of the data. We identified two forms of power which senior managerial decision-makers drew upon in order to 'hold the line'. Firstly, discursive power, which through an emphasis on evidence, better patient outcomes, professional support and clinical credibility alongside a tightly managed consultation process, helped to set an agenda that was broadly receptive to the overall decision to change stroke services in the capital in a radical way. Secondly, once the essential parameters of the decision to change services had been agreed, senior managerial decision-makers 'held the line' through hierarchical New Public Management style power to minimise the traditional pressures to de-radicalise the reconfiguration through 'top down' decision-making. We problematise the concept of 'holding the line' and explore the power implications of such managerial approaches in the early phases of health service reconfiguration. We highlight the importance of evidence for senior managerial

  12. Testing Students’ Entrepreneurial Self-Efficacy as an Early Predictor of Entrepreneurial Activities. Evidence From the SEAS Project

    Directory of Open Access Journals (Sweden)

    Krzysztof Zięba

    2018-01-01

    Full Text Available Over the last forty years, since Bandura (1977 introduced the concept of selfefcacy, there have been a constantly growing number of research publicatons using this concept. Its early development resulted in the creaton of a new construct of entrepreneurial self-efcacy (ESE proposed for the frst tme by (Chen et al. 1998. Since then, many different groups of research concerning ESE have emerged - one of them is the study of ESE of students. With regard to this partcular group, a recent tendency to study ESE in a pre-post setng can be notced i.a. Karlsson, Moberg (2013, Shinnar, Hsu, Powell (2014, Ismail, Zain, Zulihar (2015. Due to the increasing interest in entrepreneurial self-efcacy research and the need to fll the gap in the literature with regard to European post-communist countries (and partcularly – Poland (Drnovsek, Wincent, Cardon, 2010, in this paper we present a brief overview of ESE research and pose the queston whether ESE of Polish students can serve as an early predictor of their subsequent entrepreneurial actvites, potentally leading them to nascent entrepreneurship. The research material was collected from the SEAS (Survey on Entrepreneurial Attudes of Students Project carried out at the Faculty of Management and Economics, Gdańsk University of Technology. The research sample was composed of 72 students - ESE was measured in a pre-post setng using a single item based on a fve-point Likert scale. One of the research conclusions is that ESE manifested by student-beginners seems to influence their later entrepreneurial behavior in a statstcally signifcant way - potentally making ESE a valuable early predictor of future entrepreneurial actvites. In the concluding part of the study, limitatons are discussed and future study developments are indicated.

  13. Evidence of compromised blood-spinal cord barrier in early and late symptomatic SOD1 mice modeling ALS.

    Directory of Open Access Journals (Sweden)

    Svitlana Garbuzova-Davis

    2007-11-01

    Full Text Available The blood-brain barrier (BBB, blood-spinal cord barrier (BSCB, and blood-cerebrospinal fluid barrier (BCSFB control cerebral/spinal cord homeostasis by selective transport of molecules and cells from the systemic compartment. In the spinal cord and brain of both ALS patients and animal models, infiltration of T-cell lymphocytes, monocyte-derived macrophages and dendritic cells, and IgG deposits have been observed that may have a critical role in motor neuron damage. Additionally, increased levels of albumin and IgG have been found in the cerebrospinal fluid in ALS patients. These findings suggest altered barrier permeability in ALS. Recently, we showed disruption of the BBB and BSCB in areas of motor neuron degeneration in the brain and spinal cord in G93A SOD1 mice modeling ALS at both early and late stages of disease using electron microscopy. Examination of capillary ultrastructure revealed endothelial cell degeneration, which, along with astrocyte alteration, compromised the BBB and BSCB. However, the effect of these alterations upon barrier function in ALS is still unclear. The aim of this study was to determine the functional competence of the BSCB in G93A mice at different stages of disease.Evans Blue (EB dye was intravenously injected into ALS mice at early or late stage disease. Vascular leakage and the condition of basement membranes, endothelial cells, and astrocytes were investigated in cervical and lumbar spinal cords using immunohistochemistry. Results showed EB leakage in spinal cord microvessels from all G93A mice, indicating dysfunction in endothelia and basement membranes and confirming our previous ultrastructural findings on BSCB disruption. Additionally, downregulation of Glut-1 and CD146 expressions in the endothelial cells of the BSCB were found which may relate to vascular leakage.Results suggest that the BSCB is compromised in areas of motor neuron degeneration in ALS mice at both early and late stages of the disease.

  14. Do early care and education services improve language development for maltreated children? Evidence from a national child welfare sample.

    Science.gov (United States)

    Merritt, Darcey H; Klein, Sacha

    2015-01-01

    Young children under 6 years old are over-represented in the U.S. child welfare system (CWS). Due to their exposure to early deprivation and trauma, they are also highly vulnerable to developmental problems, including language delays. High quality early care and education (ECE) programs (e.g. preschool, Head Start) can improve children's development and so policymakers have begun calling for increased enrollment of CWS-supervised children in these programs. However, it is not a given that ECE will benefit all children who experience maltreatment. Some types of maltreatment may result in trauma-related learning and behavior challenges or developmental deficits that cause children to respond to ECE settings differently. The current study uses data from a nationally representative survey of children in the U.S. child welfare system, the National Survey of Child and Adolescent Well-Being II, to assess whether young CWS-supervised children (N=1,652) who were enrolled in ECE had better language development outcomes 18 months later than those not enrolled in ECE. We also explore whether the type of maltreatment that brought children to the CWS' attention moderates the relationship between ECE and children's language development. After controlling for children's initial scores on the Preschool Language Scale (PLS-3), type(s) of maltreatment experienced, and child and caregiver demographics, we found that ECE participation predicted better PLS-3 scores at follow-up, with a positive interaction between ECE participation and supervisory neglect. ECE seems to be beneficial for CWS-involved children's early language development, especially for children referred to the CWS because they lack appropriate parent supervision at home. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Divorce and social class during the early stages of the divorce revolution: evidence from Flanders and the Netherlands.

    Science.gov (United States)

    Kalmijn, Matthijs; Vanassche, Sofie; Matthijs, Koenraad

    2011-01-01

    In times of low divorce rates (such as the nineteenth century and early twentieth century), the authors expect higher social strata to have the highest divorce chances as they are better equipped to break existing barriers to divorce. In this article, the authors analyze data from marriage certificates to assess whether there was a positive effect of occupational class on divorce in Belgium (Flanders) and the Netherlands. Their results for the Netherlands show a positive association between social class and divorce, particularly among the higher cultural groups. In Flanders, the authors do not find this, but they observe a negative association between illiteracy and divorce, an observation pointing in the same direction.

  16. Early Pliocene Hiatus in Sand Output by the Colorado River: Evidence From Marine Deposits in the Salton Trough, Southern California

    Science.gov (United States)

    Dorsey, R. J.; Bykerk-Kauffman, A.

    2015-12-01

    Early Pliocene deposits in the western Salton Trough preserve a high-fidelity record of sediment dispersal into the marine realm during initiation and early evolution of the Colorado River (CR). Grain-size fractionation, sediment routing, and transport dynamics of the early CR delta are recorded in sediments of the Fish Creek - Vallecito basin, which was located ~100 km south of Yuma along the transform plate boundary at 5 Ma. Early Pliocene delivery of CR sand to the basin took place in two distinct pulses: (1) deposition of sandy turbidites (Wind Caves Mbr of the Latrania Fm) in a restricted submarine canyon at Split Mt Gorge between ~5.3 and 5.1 Ma; and (2) progradation of a thick, widespread, coarsening-up deltaic sequence of marine mudstone, sandstone, and coquinas (Deguynos Fm) between ~4.8 and 4.2 Ma. Estimated flux of CR sediment during Wind Caves deposition was weak (~3-5 Mt/yr) compared to the long-term average (172±64 Mt/yr). The two pulses of CR sand input are separated by the Coyote Clay (CC, ~5.1-4.8 Ma), a regionally correlable, greenish-yellow-weathering marine claystone unit at the base of the Deguynos Fm. CC gradationally overlies Wind Caves turbidites in the area of the paleocanyon. In contrast, in the Coyote Mts 15-23 km to the south and SE, CC rests on coarse-grained locally-derived late Miocene sedimentary rocks, Alverson volcanics, and metamorphic basement rock along a regional unconformity. Identical claystone facies occur in the NW Indio Hills (restores to Yuma at the mouth of the CR at 5 Ma), and Sierra Cucapa in Mexico (~200 km south of Yuma at 5 Ma). Marine localities outside of the Wind Caves paleocanyon experienced slow to negligible sedimentation along a rugged rocky shoreline until abrupt arrival of CR-derived clay. CC accumulated in a sand-starved, pro-delta marine setting (Winker, 1987) over an inferred N-S distance of ~200 km. We therefore reject an alternate hypothesis that CC accumulated on the muddy slope of the prograding CR

  17. Early Jurassic diversification of pycnodontiform fishes (Actinopterygii, Neopterygii) after the end-Triassic extinction event: evidence from a new genus and species, Grimmenodon aureum.

    Science.gov (United States)

    Stumpf, Sebastian; Ansorge, Jörg; Pfaff, Cathrin; Kriwet, Jürgen

    2017-07-04

    A new genus and species of pycnodontiform fishes, Grimmenodon aureum , from marginal marine, marine-brackish lower Toarcian ( Harpoceras exaratum ammonite subzone) clay deposits of Grimmen in northeastern Germany is described. The single specimen represents a diagnostic left prearticular dentition characterized by unique tooth arrangement and ornamentation patterns. Grimmenodon aureum , gen. et sp. nov., is the second unambiguously identified pycnodontiform species from the Early Jurassic, in addition to Eomesodon liassicus from the early Lower Jurassic of western Europe. We also report an indeterminate pycnodontiform tooth crown from the upper Pliensbachian ( Pleuroceras apyrenum ammonite subzone) of the same site. The material expands the Early Jurassic range of pycnodontiforms significantly northwards and confirms their presence before and immediately following the onset of the Toarcian Oceanic Anoxic Event (T-OAE) in the marginal marine ecosystems south of the Fennoscandian Shield. Moreover, the new records indicate that the Early Jurassic diversity of pycnodontiform fishes was greater than previously assumed and probably equaled that of the Late Triassic. Therefore, it is hypothesized that the Triassic-Jurassic mass extinction event did not affect pycnodontiform fishes significantly. Micro-computed tomography was used to study the internal anatomy of the prearticular of Grimmenodon aureum , gen. et sp. nov. Our results show that no replacement teeth were formed within the tooth-bearing bone but rather were added posteriorly to functional teeth. http://zoobank.org/urn:lsid:zoobank.org:pub:A56BDE9C-40C4-4CFA-9C2E-F5FA35A66F2 Citation for this article: Stumpf, S., J. Ansorge, C. Pfaff, and J. Kriwet. 2017. Early Jurassic diversification of pycnodontiform fishes (Actinopterygii, Neopterygii) after the end-Triassic extinction event: Evidence from a new genus and species, Grimmenodon aureum . Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1344679.

  18. New Empirical Evidence on the Validity and the Reliability of the Early Life Stress Questionnaire in a Polish Sample.

    Science.gov (United States)

    Sokołowski, Andrzej; Dragan, Wojciech Ł

    2017-01-01

    Background: The Early Life Stress Questionnaire (ELSQ) is widely used to estimate the prevalence of negative events during childhood, including emotional, physical, verbal, sexual abuse, negligence, severe conflicts, separation, parental divorce, substance abuse, poverty, and so forth. Objective: This study presents the psychometric properties of the Polish adaptation of the ELSQ. It also verifies if early life stress (ELS) is a good predictor of psychopathology symptoms during adulthood. Materials and Methods: We analyzed data from two samples. Sample 1 was selected by random quota method from across the country and included 609 participants aged 18-50 years, 306 women (50.2%) and 303 men (49.8%). Sample 2 contained 503 young adults (253 women and 250 men) aged 18-25. Confirmatory and exploratory factor analyses were used to measure ELSQ internal consistency. The validity was based on the relation to psychopathological symptoms and substance misuse. Results: Results showed good internal consistency and validity. Exploratory factor analysis indicates a six-factor structure of the ELSQ. ELS was related to psychopathology in adulthood, including depressive, sociophobic, vegetative as well as pain symptoms. ELSQ score correlated also with alcohol use, but not nicotine dependence. Moreover, ELS was correlated with stress in adulthood. Conclusion: The findings indicate that the Polish version of the ELSQ is a valid and reliable instrument for assessing ELS in the Polish population and may be applied in both clinical and community samples.

  19. Musicians' Enhanced Neural Differentiation of Speech Sounds Arises Early in Life: Developmental Evidence from Ages 3 to 30

    Science.gov (United States)

    Strait, Dana L.; O'Connell, Samantha; Parbery-Clark, Alexandra; Kraus, Nina

    2014-01-01

    The perception and neural representation of acoustically similar speech sounds underlie language development. Music training hones the perception of minute acoustic differences that distinguish sounds; this training may generalize to speech processing given that adult musicians have enhanced neural differentiation of similar speech syllables compared with nonmusicians. Here, we asked whether this neural advantage in musicians is present early in life by assessing musically trained and untrained children as young as age 3. We assessed auditory brainstem responses to the speech syllables /ba/ and /ga/ as well as auditory and visual cognitive abilities in musicians and nonmusicians across 3 developmental time-points: preschoolers, school-aged children, and adults. Cross-phase analyses objectively measured the degree to which subcortical responses differed to these speech syllables in musicians and nonmusicians for each age group. Results reveal that musicians exhibit enhanced neural differentiation of stop consonants early in life and with as little as a few years of training. Furthermore, the extent of subcortical stop consonant distinction correlates with auditory-specific cognitive abilities (i.e., auditory working memory and attention). Results are interpreted according to a corticofugal framework for auditory learning in which subcortical processing enhancements are engendered by strengthened cognitive control over auditory function in musicians. PMID:23599166

  20. A Swedish family with de novo alpha-synuclein A53T mutation: evidence for early cortical dysfunction

    DEFF Research Database (Denmark)

    Puschmann, Andreas; Ross, Owen A; Vilariño-Güell, Carles

    2009-01-01

    A de novo alpha-synuclein A53T (p.Ala53 Th; c.209G > A) mutation has been identified in a Swedish family with autosomal dominant Parkinson's disease (PD). Two affected individuals had early-onset (before 31 and 40 years), severe levodopa-responsive PD with prominent dysphasia, dysarthria, and cog......A de novo alpha-synuclein A53T (p.Ala53 Th; c.209G > A) mutation has been identified in a Swedish family with autosomal dominant Parkinson's disease (PD). Two affected individuals had early-onset (before 31 and 40 years), severe levodopa-responsive PD with prominent dysphasia, dysarthria......) and the Greek-American Family H kindreds. One unaffected family member carried the mutation haplotype without the c.209A mutation, strongly suggesting its de novo occurrence within this family. Furthermore, a novel mutation c.488G > A (p.Arg163His; R163H) in the presenilin-2 (PSEN2) gene was detected...

  1. Late Miocene-Early Pliocene reactivation of the Main Boundary Thrust: Evidence from the seismites in southeastern Kumaun Himalaya, India

    Science.gov (United States)

    Mishra, Anurag; Srivastava, Deepak C.; Shah, Jyoti

    2013-05-01

    Tectonic history of the Himalaya is punctuated by successive development of the faults that run along the boundaries between different lithotectonic terrains. The Main Boundary Fault, defining the southern limit of the Lesser Himalayan terrain, is tectonically most active. A review of published literature reveals that the nature and age of reactivation events on the Main Boundary Fault is one of the poorly understood aspects of the Himalayan orogen. By systematic outcrop mapping of the seismites, this study identifies a Late Miocene-Early Pliocene reactivation on the Main Boundary Thrust in southeast Kumaun Himalaya. Relatively friable and cohesionless Neogene sedimentary sequences host abundant soft-sediment deformation structures in the vicinity of the Main Boundary Thrust. Among a large variety of structures, deformed cross-beds, liquefaction pockets, slump folds, convolute laminations, sand dykes, mushroom structures, fluid escape structures, flame and load structures and synsedimentary faults are common. The morphological attributes, the structural association and the distribution pattern of the soft-sediment deformation structures with respect to the Main Boundary Fault strongly suggest their development by seismically triggered liquefaction and fluidization. Available magnetostratigraphic age data imply that the seismites were developed during a Late Miocene-Early Pliocene slip on the Main Boundary Thrust. The hypocenter of the main seismic event may lie on the Main Boundary Thrust or to the north of the study area on an unknown fault or the Basal Detachment Thrust.

  2. Cesarean section and risk of obesity in childhood, adolescence, and early adulthood: evidence from 3 Brazilian birth cohorts.

    Science.gov (United States)

    Barros, Fernando C; Matijasevich, Alicia; Hallal, Pedro C; Horta, Bernardo L; Barros, Aluísio J; Menezes, Ana B; Santos, Iná S; Gigante, Denise P; Victora, Cesar G

    2012-02-01

    The number of cesarean sections (CSs) is increasing in many countries, and there are concerns about their short- and long-term effects. A recent Brazilian study showed a 58% higher prevalence of obesity in young adults born by CS than in young adults born vaginally. Because CS-born individuals do not make contact at birth with maternal vaginal and intestinal bacteria, the authors proposed that this could lead to long-term changes in the gut microbiota that could contribute to obesity. We assessed whether CS births lead to increased obesity during childhood, adolescence, and early adulthood in 3 birth cohorts. We analyzed data from 3 birth-cohort studies started in 1982, 1993, and 2004 in Southern Brazil. Subjects were assessed at different ages until 23 y of age. Poisson regression was used to estimate prevalence ratios with adjustment for ≤15 socioeconomic, demographic, maternal, anthropometric, and behavioral covariates. In the crude analyses, subjects born by CS had ∼50% higher prevalence of obesity at 4, 11, and 15 y of age but not at 23 y of age. After adjustment for covariates, prevalence ratios were markedly reduced and no longer significant for men or women. The only exception was an association for 4-y-old boys in the 1993 cohort, which was not observed in the other 2 cohorts or for girls. In these 3 birth cohorts, CSs do not seem to lead to an important increased risk of obesity during childhood, adolescence, or early adulthood.

  3. Genetic and proteomic evidence for roles of Drosophila SUMO in cell cycle control, Ras signaling, and early pattern formation.

    Directory of Open Access Journals (Sweden)

    Minghua Nie

    2009-06-01

    Full Text Available SUMO is a protein modifier that is vital for multicellular development. Here we present the first system-wide analysis, combining multiple approaches, to correlate the sumoylated proteome (SUMO-ome in a multicellular organism with the developmental roles of SUMO. Using mass-spectrometry-based protein identification, we found over 140 largely novel SUMO conjugates in the early Drosophila embryo. Enriched functional groups include proteins involved in Ras signaling, cell cycle, and pattern formation. In support of the functional significance of these findings, sumo germline clone embryos exhibited phenotypes indicative of defects in these same three processes. Our cell culture and immunolocalization studies further substantiate roles for SUMO in Ras signaling and cell cycle regulation. For example, we found that SUMO is required for efficient Ras-mediated MAP kinase activation upstream or at the level of Ras activation. We further found that SUMO is dynamically localized during mitosis to the condensed chromosomes, and later also to the midbody. Polo kinase, a SUMO substrate found in our screen, partially colocalizes with SUMO at both sites. These studies show that SUMO coordinates multiple regulatory processes during oogenesis and early embryogenesis. In addition, our database of sumoylated proteins provides a valuable resource for those studying the roles of SUMO in development.

  4. Pertuzumab for the Neoadjuvant Treatment of Early-Stage HER2-Positive Breast Cancer: An Evidence Review Group Perspective of a NICE Single Technology Appraisal.

    Science.gov (United States)

    Squires, Hazel; Pandor, Abdullah; Thokala, Praveen; Stevens, John W; Kaltenthaler, Eva; Clowes, Mark; Coleman, Robert; Wyld, Lynda

    2018-01-01

    As part of its single technology appraisal process, the National Institute for Health and Care Excellence invited the manufacturer of pertuzumab (Perjeta ® ; Roche Products Limited) to submit evidence of its clinical and cost- effectiveness for the neoadjuvant treatment of women with high-risk, early-stage, HER2-positive breast cancer when used in combination with trastuzumab and chemotherapy. High-risk women included those with locally advanced (including inflammatory) breast cancer and women with high-risk early-stage breast cancer (classified as T2/3 or N1). The School of Health and Related Research Technology Appraisal Group at the University of Sheffield was commissioned to act as the independent Evidence Review Group. This article presents the critical review of the company's submission by the Evidence Review Group and the outcome of the National Institute for Health and Care Excellence guidance. The clinical data were mainly taken from a phase II, randomised, open-label, active controlled study (NeoSphere), which reported a significant advantage in terms of pathological complete response rates of pertuzumab in combination with trastuzumab and chemotherapy, compared with trastuzumab alone with chemotherapy (45.8 vs. 29.0%, p = 0.0141). The company did not make any indirect comparisons. A meta-analysis of 12 neoadjuvant studies investigating the relationship between pathological complete response and event-free survival was used to extrapolate the outcomes reported in the NeoSphere study. A cardiac safety study (TRYPHAENA) demonstrated the safety of pertuzumab. The company undertook a model-based economic evaluation of neoadjuvant pertuzumab plus trastuzumab and docetaxel compared with neoadjuvant trastuzumab and docetaxel over a lifetime horizon from the National Health Service and Personal Social Services perspective. The probabilistic incremental cost-effectiveness ratio was estimated to be £20,104 per quality-adjusted life-year gained for pertuzumab

  5. Meteorological and intelligence evidence of long-distance transit of chemical weapons fallout from bombing early in the 1991 Persian Gulf War.

    Science.gov (United States)

    Tuite, James J; Haley, Robert W

    2013-01-01

    Coalition bombings on the night of 18-19 January 1991, early in the Gulf War, targeted the Iraqi chemical weapons infrastructure. On 19 January 1991, nerve agent alarms sounded within Coalition positions hundreds of kilometers to the south, and the trace presence of sarin vapor was identified by multiple technologies. Considering only surface dispersion of plumes from explosions, officials concluded that the absence of casualties around bombed sites precluded long-distance transit of debris to US troop positions to explain the alarms and detections. Consequently, they were discounted as false positives, and low-level nerve agent exposure early in the air war was disregarded in epidemiologic investigations of chronic illnesses. Newly assembled evidence indicates that plumes from those nighttime bombings of Iraqi chemical facilities would have traversed the stable nocturnal boundary layer and penetrated the residual layer where they would be susceptible to rapid transit by supergeostrophic winds. This explanation is supported by plume height predictions, available weather charts, weather satellite images showing transit of a hot air mass, effects of solar mixing of atmospheric layers, and observations of a stationary weather front and thermal inversion in the region. Current evidence supports long-distance transit. Epidemiologic studies of chronic postwar illness should be reassessed using veterans' reports of hearing nerve agent alarms as the measure of exposure. Copyright © 2012 S. Karger AG, Basel.

  6. Evidence for the essentiality of arachidonic and docosahexaenoic acid in the postnatal maternal and infant diet for the development of the infant's immune system early in life.

    Science.gov (United States)

    Richard, Caroline; Lewis, Erin D; Field, Catherine J

    2016-05-01

    Long-chain polyunsaturated fatty acids (LCPUFA), especially the balance between arachidonic (AA) and docosahexaenoic (DHA) acids are known to have important immunomodulatory roles during the postnatal period when the immune system is rapidly developing. AA and DHA are required in infant formula in many countries but are optional in North America. The rationale for adding these LCPUFA to full-term formula is based on their presence in breast milk and randomized controlled studies that suggest improved cognitive function in preterm infants, but results are more variable in full-term infants. Recently, the European Food Safety Authority has proposed, based on a lack of functional evidence, that AA is not required in infant formula for full-term infants during the first year of life but DHA should remain mandatory. The purpose of this review is to review the evidence from epidemiological and intervention studies regarding the essentiality of AA and DHA in the postnatal infant and maternal diet (breast-feeding) for the immune system development early in life. Although studies support the essentiality of DHA for the immune system development, more research is needed to rule out the essentiality of AA. Nevertheless, intervention studies have demonstrated improvement in many markers of immune function in infants fed formula supplemented with AA and DHA compared with unsupplemented formula, which appears to consistently result in beneficial health outcomes including reduction in the risk of developing allergic and atopic disease early in life.

  7. Implicit conditioning of faces via the social regulation of emotion: ERP evidence of early attentional biases for security conditioned faces.

    Science.gov (United States)

    Beckes, Lane; Coan, James A; Morris, James P

    2013-08-01

    Not much is known about the neural and psychological processes that promote the initial conditions necessary for positive social bonding. This study explores one method of conditioned bonding utilizing dynamics related to the social regulation of emotion and attachment theory. This form of conditioning involves repeated presentations of negative stimuli followed by images of warm, smiling faces. L. Beckes, J. Simpson, and A. Erickson (2010) found that this conditioning procedure results in positive associations with the faces measured via a lexical decision task, suggesting they are perceived as comforting. This study found that the P1 ERP was similarly modified by this conditioning procedure and the P1 amplitude predicted lexical decision times to insecure words primed by the faces. The findings have implications for understanding how the brain detects supportive people, the flexibility and modifiability of early ERP components, and social bonding more broadly. Copyright © 2013 Society for Psychophysiological Research.

  8. Geochemical evidence for subduction in the early Archaean from quartz-carbonate-fuchsite mineralization, Isua Supracrustal Belt, West Greenland

    DEFF Research Database (Denmark)

    Pope, Emily Catherine; Rosing, Minik Thorleif; Bird, Dennis K.

    Quartz, carbonate and fuchsite (chromian muscovite) is a common metasomatic assemblage observed in orogenic gold systems, both in Phanerozoic convergent margin settings, and within supracrustal and greenstone belts of Precambrian rocks. Geologic and geochemical observations in younger orogenic...... systems suggest that ore-forming metasomatic fluids are derived from subduction-related devolitilization reactions, implying that orogenic Au-deposits in Archaean and Proterozoic supracrustal rock suites are related to subduction-style plate tectonics beginning early in Earth history. Justification...... with Phanerozoic orogenic deposits and that this type of metasomatism is a unique result of subduction-related processes. Fuchsite from the ISB has a δ18O and δD of 7.7 to 17.9‰ and -115 to -61‰, respectively. δ18O of quartz from the same rocks is between 10.3 and 18.6‰. Muscovite-quartz oxygen isotope thermometry...

  9. Outcomes and impact of HIV prevention, ART and TB programs in Swaziland--early evidence from public health triangulation.

    Science.gov (United States)

    van Schalkwyk, Cari; Mndzebele, Sibongile; Hlophe, Thabo; Garcia Calleja, Jesus Maria; Korenromp, Eline L; Stoneburner, Rand; Pervilhac, Cyril

    2013-01-01

    Swaziland's severe HIV epidemic inspired an early national response since the late 1980s, and regular reporting of program outcomes since the onset of a national antiretroviral treatment (ART) program in 2004. We assessed effectiveness outcomes and mortality trends in relation to ART, HIV testing and counseling (HTC), tuberculosis (TB) and prevention of mother to child transmission (PMTCT). Data triangulated include intervention coverage and outcomes according to program registries (2001-2010), hospital admissions and deaths disaggregated by age and sex (2001-2010) and population mortality estimates from the 1997 and 2007 censuses and the 2007 demographic and health survey. By 2010, ART reached 70% of the estimated number of people living with HIV/AIDS with CD4impact to specific interventions (versus natural epidemic dynamics) will require additional data from future household surveys, and improved routine (program, surveillance, and hospital) data at district level.

  10. Early use of orthographic information in spoken word recognition: Event-related potential evidence from the Korean language.

    Science.gov (United States)

    Kwon, Youan; Choi, Sungmook; Lee, Yoonhyoung

    2016-04-01

    This study examines whether orthographic information is used during prelexical processes in spoken word recognition by investigating ERPs during spoken word processing for Korean words. Differential effects due to orthographic syllable neighborhood size and sound-to-spelling consistency on P200 and N320 were evaluated by recording ERPs from 42 participants during a lexical decision task. The results indicate that P200 was smaller for words whose orthographic syllable neighbors are large in number rather than those that are small. In addition, a word with a large orthographic syllable neighborhood elicited a smaller N320 effect than a word with a small orthographic syllable neighborhood only when the word had inconsistent sound-to-spelling mapping. The results provide support for the assumption that orthographic information is used early during the prelexical spoken word recognition process. © 2015 Society for Psychophysiological Research.

  11. Provenance Studies on Metal Artefacts of the Early Danish Bronze Age: Comparing lead isotope data with the archaeological evidence

    DEFF Research Database (Denmark)

    Nørgaard, Heide Wrobel; Vandkilde, Helle; Pernicka, Ernst

    2017-01-01

    As early as 2100 BCE, societies in the hotspot zone of Denmark and Scania began to use metal. However, this region has not exploited metal ores of their own; therefore the origin of the metal used is of key significance to understanding and modelling the cross-European interconnectivities that were...... established through the necessity of trading. The Nordic region was for the very first time fully dependent on one crucial exogenous resource. The related change within the political economy surely resulted in the establishment of the Nordic Bronze Age. However, little is known about the significance......, the extent and the direction of this metal trade. For the Bronze Age in northern Europe (NBA) two possible transport routes stand opposite each other; on the one hand a continental route that connected the Alps, Central Europe and the NBA; and on the other hand, a maritime route linking Mediterranean...

  12. Early enrichment effects on brain development in hatchery-reared Atlantic salmon (Salmo salar): no evidence for a critical period

    DEFF Research Database (Denmark)

    Näslund, Joacim; Aarestrup, Kim; Thomassen, Søren T.

    2012-01-01

    was released into nature and recaptured at smoltification. These stream-reared smolts developed smaller brains than the hatchery reared smolts, irrespective of initial enrichment treatment. These novel findings do not support the hypothesis that there is a critical early period determining the brain growth...... trajectory. In contrast, our results indicate that brain growth is plastic in relation to environment. In addition, we show allometric growth in brain substructures over juvenile development, which suggests that comparisons between groups of different body size should be made with caution. These results can......In hatcheries, fish are normally reared in barren environments, which have been reported to affect their phenotypic development compared with wild conspecifics. In this study, Atlantic salmon (Salmo salar) alevins were reared in conventional barren hatchery trays or in either of two types...

  13. Research on early warning of food security using a system dynamics model: evidence from Jiangsu province in China.

    Science.gov (United States)

    Xu, Jianling; Ding, Yi

    2015-01-01

    Analyzing the early warning of food security, this paper sets the self-sufficiency rate as the principal indicator in a standpoint of supplement. It is common to use the quantitative methods to forecast and warning the insecurity. However, this paper considers more about the probable outcome when the government intervenes. By constructing the causal feedbacks among grain supplement, demand, productive input, and the policy factors to simulate the future food security in Jiangsu province, conclusions can be drawn as the following: (1) The situation of food security is insecure if the self-sufficiency rate is under 68.3% according to the development of system inertia. (2) it is difficult to guarantee the food security in Jiangsu just depending on the increase of grain sown area. (3) The valid solution to ensure the food security in Jiangsu is to improve the productivity. © 2015 Institute of Food Technologists®

  14. Evidence for a constant initial mass function in early-type galaxies based on their X-ray binary populations

    Energy Technology Data Exchange (ETDEWEB)

    Peacock, Mark B.; Zepf, Stephen E. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Maccarone, Thomas J. [Texas Tech University, Physics Department, Box 41051, Lubbock, TX 79409 (United States); Kundu, Arunav [Eureka Scientific, Inc., 2452 Delmer Street, Suite 100 Oakland, CA 94602 (United States); Gonzalez, Anthony H. [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Lehmer, Bret D. [The Johns Hopkins University, Homewood Campus, Baltimore, MD 21218 (United States); Maraston, Claudia, E-mail: mpeacock@msu.edu [Institute of Cosmology and Gravitation, Dennis Sciama Building, Burnaby Road, Portsmouth PO1 3FX (United Kingdom)

    2014-04-01

    A number of recent studies have proposed that the stellar initial mass function (IMF) of early type galaxies varies systematically as a function of galaxy mass, with higher mass galaxies having bottom-heavy IMFs. These bottom-heavy IMFs have more low-mass stars relative to the number of high mass stars, and therefore naturally result in proportionally fewer neutron stars (NSs) and black holes (BHs). In this paper, we specifically predict the variation in the number of BHs and NSs based on the power-law IMF variation required to reproduce the observed mass-to-light ratio trends with galaxy mass. We then test whether such variations are observed by studying the field low-mass X-ray binary (LMXB) populations of nearby early-type galaxies. In these binaries, an NS or BH accretes matter from a low-mass donor star. Their number is therefore expected to scale with the number of BHs and NSs present in a galaxy. We find that the number of LMXBs per K-band light is similar among the galaxies in our sample. These data therefore demonstrate the uniformity of the slope of the IMF from massive stars down to those now dominating the K-band light and are consistent with an invariant IMF. Our results are inconsistent with an IMF which varies from a Kroupa/Chabrier like IMF for low-mass galaxies to a steep power-law IMF (with slope x = 2.8) for high mass galaxies. We discuss how these observations constrain the possible forms of the IMF variations and how future Chandra observations can enable sharper tests of the IMF.

  15. Local adaptation at the transcriptome level in brown trout: evidence from early life history temperature genomic reaction norms.

    Directory of Open Access Journals (Sweden)

    Kristian Meier

    Full Text Available Local adaptation and its underlying molecular basis has long been a key focus in evolutionary biology. There has recently been increased interest in the evolutionary role of plasticity and the molecular mechanisms underlying local adaptation. Using transcriptome analysis, we assessed differences in gene expression profiles for three brown trout (Salmo trutta populations, one resident and two anadromous, experiencing different temperature regimes in the wild. The study was based on an F2 generation raised in a common garden setting. A previous study of the F1 generation revealed different reaction norms and significantly higher QST than FST among populations for two early life-history traits. In the present study we investigated if genomic reaction norm patterns were also present at the transcriptome level. Eggs from the three populations were incubated at two temperatures (5 and 8 degrees C representing conditions encountered in the local environments. Global gene expression for fry at the stage of first feeding was analysed using a 32k cDNA microarray. The results revealed differences in gene expression between populations and temperatures and population × temperature interactions, the latter indicating locally adapted reaction norms. Moreover, the reaction norms paralleled those observed previously at early life-history traits. We identified 90 cDNA clones among the genes with an interaction effect that were differently expressed between the ecologically divergent populations. These included genes involved in immune- and stress response. We observed less plasticity in the resident as compared to the anadromous populations, possibly reflecting that the degree of environmental heterogeneity encountered by individuals throughout their life cycle will select for variable level of phenotypic plasticity at the transcriptome level. Our study demonstrates the usefulness of transcriptome approaches to identify genes with different temperature reaction

  16. Evidence for a constant initial mass function in early-type galaxies based on their X-ray binary populations

    International Nuclear Information System (INIS)

    Peacock, Mark B.; Zepf, Stephen E.; Maccarone, Thomas J.; Kundu, Arunav; Gonzalez, Anthony H.; Lehmer, Bret D.; Maraston, Claudia

    2014-01-01

    A number of recent studies have proposed that the stellar initial mass function (IMF) of early type galaxies varies systematically as a function of galaxy mass, with higher mass galaxies having bottom-heavy IMFs. These bottom-heavy IMFs have more low-mass stars relative to the number of high mass stars, and therefore naturally result in proportionally fewer neutron stars (NSs) and black holes (BHs). In this paper, we specifically predict the variation in the number of BHs and NSs based on the power-law IMF variation required to reproduce the observed mass-to-light ratio trends with galaxy mass. We then test whether such variations are observed by studying the field low-mass X-ray binary (LMXB) populations of nearby early-type galaxies. In these binaries, an NS or BH accretes matter from a low-mass donor star. Their number is therefore expected to scale with the number of BHs and NSs present in a galaxy. We find that the number of LMXBs per K-band light is similar among the galaxies in our sample. These data therefore demonstrate the uniformity of the slope of the IMF from massive stars down to those now dominating the K-band light and are consistent with an invariant IMF. Our results are inconsistent with an IMF which varies from a Kroupa/Chabrier like IMF for low-mass galaxies to a steep power-law IMF (with slope x = 2.8) for high mass galaxies. We discuss how these observations constrain the possible forms of the IMF variations and how future Chandra observations can enable sharper tests of the IMF.

  17. Evidence of early alterations in adipose tissue biology and function and its association with obesity-related inflammation and insulin resistance in children.

    Science.gov (United States)

    Landgraf, Kathrin; Rockstroh, Denise; Wagner, Isabel V; Weise, Sebastian; Tauscher, Roy; Schwartze, Julian T; Löffler, Dennis; Bühligen, Ulf; Wojan, Magdalena; Till, Holger; Kratzsch, Jürgen; Kiess, Wieland; Blüher, Matthias; Körner, Antje

    2015-04-01

    Accumulation of fat mass in obesity may result from hypertrophy and/or hyperplasia and is frequently associated with adipose tissue (AT) dysfunction in adults. Here we assessed early alterations in AT biology and function by comprehensive experimental and clinical characterization of 171 AT samples from lean and obese children aged 0 to 18 years. We show an increase in adipocyte size and number in obese compared with lean children beginning in early childhood. These alterations in AT composition in obese children were accompanied by decreased basal lipolytic activity and significantly enhanced stromal vascular cell proliferation in vitro, potentially underlying the hypertrophy and hyperplasia seen in obese children, respectively. Furthermore, macrophage infiltration, including the formation of crown-like structures, was increased in AT of obese children from 6 years on and was associated with higher hs-CRP serum levels. Clinically, adipocyte hypertrophy was not only associated with leptin serum levels but was highly and independently correlated with HOMA-IR as a marker of insulin resistance in children. In summary, we show that adipocyte hypertrophy is linked to increased inflammation in AT in obese children, thereby providing evidence that obesity-associated AT dysfunction develops in early childhood and is related to insulin resistance. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  18. The Long-term Impact of Early Life Pain On Adult Responses to Anxiety and Stress: Historical Perspectives and Empirical Evidence

    Science.gov (United States)

    Victoria, Nicole C.; Murphy, Anne Z.

    2016-01-01

    Approximately 1 in 6 infants are born prematurely each year. Typically, these infants spend 25 days in the Neonatal Intensive Care Unit (NICU) where they experience 10–18 painful and inflammatory procedures each day. Remarkably, pre-emptive analgesics and/or anesthesia are administered less than 25% of the time. Unalleviated pain during the perinatal period is associated with permanent decreases in pain sensitivity, blunted cortisol responses and high rates of neuropsychiatric disorders. To date, the mechanism(s) by which these long-term changes in stress and pain behavior occur, and whether such alterations can be prevented by appropriate analgesia at the time of insult, remains unclear. Work in our lab using a rodent model of early life pain suggests that inflammatory pain experienced on the day of birth blunts adult responses to stress- and pain-provoking stimuli, and dysregulates the hypothalamic pituitary adrenal (HPA) axis in part through a permanent upregulation in central endogenous opioid tone. This review focuses on the long-term impact of neonatal inflammatory pain on adult anxiety- and stress-related responses, and underlying neuroanatomical changes in the context of endogenous pain control and the HPA axis. These two systems are in a state of exaggerated developmental plasticity early in postnatal life, and work in concert to respond to noxious or aversive stimuli. We present empirical evidence from animal and clinical studies, and discuss historical perspectives underlying the lack of analgesia/anesthetic use for early life pain in the modern NICU. PMID:26210872

  19. Early Evidence of Acheulean Settlement in Northwestern Europe - La Noira Site, a 700 000 Year-Old Occupation in the Center of France

    Science.gov (United States)

    Moncel, Marie-Hélène; Despriée, Jackie; Voinchet, Pierre; Tissoux, Hélène; Moreno, Davinia; Bahain, Jean-Jacques; Courcimault, Gilles; Falguères, Christophe

    2013-01-01

    The human settlement of Europe during Pleistocene times was sporadic and several stages have been recognized, both from paleaoanthropological and archaeological records. If the first phase of hominin occupation (as early as 1.4 Ma) seems mainly restricted to the southern part of the continent, the second phase, characterized by specific lithic tools (handaxes), is linked to Acheulean settlements and to the emergence of Homo heidelbergensis, the ancestor of Neanderthals. This phase reached northwestern Europe and is documented in numerous sites in Germany, Great Britain and northern France, generally after 600 ka. At la Noira (Brinay, Central France), the Middle Pleistocene alluvial formation of the Cher River covers an archaeological level associated with a slope deposit (diamicton). The lithic assemblage from this level includes Large Cutting Tools (LCTs), flakes and cores, associated with numerous millstone slabs. The lithic series is classified as Acheulean on the basis of both technological and typological analyses. Cryoturbation features indicate that the slope deposits and associated archaeological level were strongly frozen and disturbed after hominin occupation and before fluvial deposition. Eight sediment samples were dated by the electron spin resonance (ESR) method and the weighted average age obtained for the fluvial sands overlying the slope deposits is 665±55 ka. This age is older than previous chronological data placing the first European Acheulean assemblages north of 45th parallel north at around 500 ka and modifies our current vision of the initial peopling of northern Europe. Acheulean settlements are older than previously assumed and the oldest evidences are not only located in southern Europe. La Noira is the oldest evidence of Acheulean presence in north-western Europe and attests to the possibility of pioneering phases of Acheulean settlement which would have taken place on a Mode 1-type substratum as early as 700 ka. The lithic assemblage

  20. Early evidence of Acheulean settlement in northwestern Europe--la Noira site, a 700,000 year-old occupation in the center of France.

    Directory of Open Access Journals (Sweden)

    Marie-Hélène Moncel

    Full Text Available The human settlement of Europe during Pleistocene times was sporadic and several stages have been recognized, both from paleaoanthropological and archaeological records. If the first phase of hominin occupation (as early as 1.4 Ma seems mainly restricted to the southern part of the continent, the second phase, characterized by specific lithic tools (handaxes, is linked to Acheulean settlements and to the emergence of Homo heidelbergensis, the ancestor of Neanderthals. This phase reached northwestern Europe and is documented in numerous sites in Germany, Great Britain and northern France, generally after 600 ka. At la Noira (Brinay, Central France, the Middle Pleistocene alluvial formation of the Cher River covers an archaeological level associated with a slope deposit (diamicton. The lithic assemblage from this level includes Large Cutting Tools (LCTs, flakes and cores, associated with numerous millstone slabs. The lithic series is classified as Acheulean on the basis of both technological and typological analyses. Cryoturbation features indicate that the slope deposits and associated archaeological level were strongly frozen and disturbed after hominin occupation and before fluvial deposition. Eight sediment samples were dated by the electron spin resonance (ESR method and the weighted average age obtained for the fluvial sands overlying the slope deposits is 665±55 ka. This age is older than previous chronological data placing the first European Acheulean assemblages north of 45(th parallel north at around 500 ka and modifies our current vision of the initial peopling of northern Europe. Acheulean settlements are older than previously assumed and the oldest evidences are not only located in southern Europe. La Noira is the oldest evidence of Acheulean presence in north-western Europe and attests to the possibility of pioneering phases of Acheulean settlement which would have taken place on a Mode 1-type substratum as early as 700 ka. The

  1. Early evidence of Acheulean settlement in northwestern Europe--la Noira site, a 700,000 year-old occupation in the center of France.

    Science.gov (United States)

    Moncel, Marie-Hélène; Despriée, Jackie; Voinchet, Pierre; Tissoux, Hélène; Moreno, Davinia; Bahain, Jean-Jacques; Courcimault, Gilles; Falguères, Christophe

    2013-01-01

    The human settlement of Europe during Pleistocene times was sporadic and several stages have been recognized, both from paleaoanthropological and archaeological records. If the first phase of hominin occupation (as early as 1.4 Ma) seems mainly restricted to the southern part of the continent, the second phase, characterized by specific lithic tools (handaxes), is linked to Acheulean settlements and to the emergence of Homo heidelbergensis, the ancestor of Neanderthals. This phase reached northwestern Europe and is documented in numerous sites in Germany, Great Britain and northern France, generally after 600 ka. At la Noira (Brinay, Central France), the Middle Pleistocene alluvial formation of the Cher River covers an archaeological level associated with a slope deposit (diamicton). The lithic assemblage from this level includes Large Cutting Tools (LCTs), flakes and cores, associated with numerous millstone slabs. The lithic series is classified as Acheulean on the basis of both technological and typological analyses. Cryoturbation features indicate that the slope deposits and associated archaeological level were strongly frozen and disturbed after hominin occupation and before fluvial deposition. Eight sediment samples were dated by the electron spin resonance (ESR) method and the weighted average age obtained for the fluvial sands overlying the slope deposits is 665±55 ka. This age is older than previous chronological data placing the first European Acheulean assemblages north of 45(th) parallel north at around 500 ka and modifies our current vision of the initial peopling of northern Europe. Acheulean settlements are older than previously assumed and the oldest evidences are not only located in southern Europe. La Noira is the oldest evidence of Acheulean presence in north-western Europe and attests to the possibility of pioneering phases of Acheulean settlement which would have taken place on a Mode 1-type substratum as early as 700 ka. The lithic assemblage

  2. Evidence for gill slits and a pharynx in Cambrian vetulicolians: implications for the early evolution of deuterostomes

    Directory of Open Access Journals (Sweden)

    Ou Qiang

    2012-10-01

    Full Text Available Abstract Background Vetulicolians are a group of Cambrian metazoans whose distinctive bodyplan continues to present a major phylogenetic challenge. Thus, we see vetulicolians assigned to groups as disparate as deuterostomes and ecdysozoans. This divergence of opinions revolves around a strikingly arthropod-like body, but one that also bears complex lateral structures on its anterior section interpreted as pharyngeal openings. Establishing the homology of these structures is central to resolving where vetulicolians sit in metazoan phylogeny. Results New material from the Chengjiang Lagerstätte helps to resolve this issue. Here, we demonstrate that these controversial structures comprise grooves with a series of openings. The latter are oval in shape and associated with a complex anatomy consistent with control of their opening and closure. Remains of what we interpret to be a musculature, combined with the capacity for the grooves to contract, indicate vetulicolians possessed a pumping mechanism that could process considerable volumes of seawater. Our observations suggest that food captured in the anterior cavity was transported to dorsal and ventral gutters, which then channeled material to the intestine. This arrangement appears to find no counterpart in any known fossil or extant arthropod (or any other ecdysozoan. Anterior lateral perforations, however, are diagnostic of deuterostomes. Conclusions If the evidence is against vetulicolians belonging to one or other group of ecdysozoan, then two phylogenetic options seem to remain. The first is that such features as vetulicolians possess are indicative of either a position among the bilaterians or deuterostomes but apart from the observation that they themselves form a distinctive and recognizable clade current evidence can permit no greater precision as to their phylogenetic placement. We argue that this is too pessimistic a view, and conclude that evidence points towards vetulicolians being

  3. Reassessment of the evidence for postcranial skeletal pneumaticity in Triassic archosaurs, and the early evolution of the avian respiratory system.

    Directory of Open Access Journals (Sweden)

    Richard J Butler

    Full Text Available Uniquely among extant vertebrates, birds possess complex respiratory systems characterised by the combination of small, rigid lungs, extensive pulmonary air sacs that possess diverticula that invade (pneumatise the postcranial skeleton, unidirectional ventilation of the lungs, and efficient crosscurrent gas exchange. Crocodilians, the only other living archosaurs, also possess unidirectional lung ventilation, but lack true air sacs and postcranial skeletal pneumaticity (PSP. PSP can be used to infer the presence of avian-like pulmonary air sacs in several extinct archosaur clades (non-avian theropod dinosaurs, sauropod dinosaurs and pterosaurs. However, the evolution of respiratory systems in other archosaurs, especially in the lineage leading to crocodilians, is poorly documented. Here, we use µCT-scanning to investigate the vertebral anatomy of Triassic archosaur taxa, from both the avian and crocodilian lineages as well as non-archosaurian diapsid outgroups. Our results confirm previous suggestions that unambiguous evidence of PSP (presence of internal pneumatic cavities linked to the exterior by foramina is found only in bird-line (ornithodiran archosaurs. We propose that pulmonary air sacs were present in the common ancestor of Ornithodira and may have been subsequently lost or reduced in some members of the clade (notably in ornithischian dinosaurs. The development of these avian-like respiratory features might have been linked to inferred increases in activity levels among ornithodirans. By contrast, no crocodile-line archosaur (pseudosuchian exhibits evidence for unambiguous PSP, but many of these taxa possess the complex array of vertebral laminae and fossae that always accompany the presence of air sacs in ornithodirans. These laminae and fossae are likely homologous with those in ornithodirans, which suggests the need for further investigation of the hypothesis that a reduced, or non-invasive, system of pulmonary air sacs may be have

  4. Early identification and intervention matters: A comprehensive review of current evidence and recommendations for the monitoring of bone health in patients with cancer.

    Science.gov (United States)

    Brodowicz, Thomas; Hadji, Peyman; Niepel, Daniela; Diel, Ingo

    2017-12-01

    Bone metastases are common in patients with advanced solid tumors, and many individuals experience debilitating skeletal-related events (SREs; e.g. pathologic fracture, hypercalcemia, radiotherapy or surgery to bone, and spinal cord compression). These events substantially affect disease outcomes, including survival and quality of life, and healthcare systems. Plain radiography is the most widely used imaging modality for the detection of bone metastases; skeletal scintigraphy, computed tomography, positron emission tomography and magnetic resonance imaging offer greater sensitivity but their use in routine practice is restricted by high costs and limited availability. Biomarkers of bone turnover may also have a role in the early detection of bone metastases and can provide valuable prognostic information on disease progression. SREs can be delayed or prevented using agents such as the receptor activator of nuclear factor kappa B ligand (RANKL) inhibitor, denosumab, and bisphosphonates. Painful bone metastases can be treated with radiofrequency ablation, radiotherapy, or radionuclides such as radium-223 dichloride, which has been shown to delay the onset of SREs in men with castration-resistant prostate cancer. Close monitoring of bone health in patients with advanced cancer may lead to early identification of individuals with bone metastases who could benefit from early intervention to prevent SREs. This review examines current guideline recommendations for assessing and monitoring bone health in patients with advanced cancer, use of biomarkers and treatment of patients with bone metastases. The emerging evidence for the potential survival benefit conferred by early intervention with denosumab and bisphosphonates is also discussed, together with best practice recommendations. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  5. Sedimentary evidence for enhanced hydrological cycling in response to rapid carbon release during the early Toarcian oceanic anoxic event

    Science.gov (United States)

    Izumi, Kentaro; Kemp, David B.; Itamiya, Shoma; Inui, Mutsuko

    2018-01-01

    A pronounced excursion in the carbon-isotope composition of biospheric carbon and coeval seawater warming during the early Toarcian (∼183 Ma) has been linked to the large-scale transfer of 12C-enriched carbon to the oceans and atmosphere. A European bias in the distribution of available data means that the precise pattern, tempo and global expression of this carbon cycle perturbation, and the associated environmental responses, remain uncertain. Here, we present a new cm-scale terrestrial-dominated carbon-isotope record through an expanded lower Toarcian section from Japan that displays a negative excursion pattern similar to marine and terrestrial carbon-isotope records documented from Europe. These new data suggest that 12C-enriched carbon was added to the biosphere in at least one rapid, millennial-scale pulse. Sedimentological analysis indicates a close association between the carbon-isotope excursion and high-energy sediment transport and enhanced fluvial discharge. Together, these data support the hypothesis that a sudden strengthening of the global hydrological cycle occurred in direct and immediate response to rapid carbon release and atmospheric warming.

  6. Promoting Early Presentation of Breast Cancer in Older Women: Implementing an Evidence-Based Intervention in Routine Clinical Practice

    International Nuclear Information System (INIS)

    Forbes, L. J. L.; Forster, A. S.; Dodd, R. H.; Tucker, L.; Laming, R.; Ramirez, A. J.; Sellars, S.; Patnick, J.

    2012-01-01

    Women over 70 with breast cancer have poorer one-year survival and present at a more advanced stage than younger women. Promoting early symptomatic presentation in older women may reduce stage cost effectively and is unlikely to lead to overdiagnosis. After examining efficacy in a randomised controlled trial, we piloted a brief health professional-delivered intervention to equip women to present promptly with breast symptoms, as an integral part of the final invited mammogram at age ∼70, in the English National Health Service Breast Screening Programme. Methods. We trained mammographers, who then offered the intervention to older women in four breast screening services. We examined breast cancer awareness at baseline and one month in women receiving the intervention, and also in a service where the intervention was not offered. Results. We trained 27 mammographers to deliver the intervention confidently to a high standard. Breast cancer awareness increased 7-fold at one month in women receiving the intervention compared with 2-fold in the comparison service (odds ratio 15.2, 95% confidence interval 10.0 to 23.2). Conclusions. The PEP Intervention can be implemented in routine clinical practice with a potency similar to that achieved in a randomised controlled trial. It has the potential to reduce delay in diagnosis for breast cancer in older women.

  7. Promoting Early Presentation of Breast Cancer in Older Women: Implementing an Evidence-Based Intervention in Routine Clinical Practice

    Science.gov (United States)

    Forbes, Lindsay J. L.; Forster, Alice S.; Dodd, Rachael H.; Tucker, Lorraine; Laming, Rachel; Sellars, Sarah; Patnick, Julietta; Ramirez, Amanda J.

    2012-01-01

    Background. Women over 70 with breast cancer have poorer one-year survival and present at a more advanced stage than younger women. Promoting early symptomatic presentation in older women may reduce stage cost effectively and is unlikely to lead to overdiagnosis. After examining efficacy in a randomised controlled trial, we piloted a brief health professional-delivered intervention to equip women to present promptly with breast symptoms, as an integral part of the final invited mammogram at age ~70, in the English National Health Service Breast Screening Programme. Methods. We trained mammographers, who then offered the intervention to older women in four breast screening services. We examined breast cancer awareness at baseline and one month in women receiving the intervention, and also in a service where the intervention was not offered. Results. We trained 27 mammographers to deliver the intervention confidently to a high standard. Breast cancer awareness increased 7-fold at one month in women receiving the intervention compared with 2-fold in the comparison service (odds ratio 15.2, 95% confidence interval 10.0 to 23.2). Conclusions. The PEP Intervention can be implemented in routine clinical practice with a potency similar to that achieved in a randomised controlled trial. It has the potential to reduce delay in diagnosis for breast cancer in older women. PMID:23213334

  8. Evidence for close side-chain packing in an early protein folding intermediate previously assumed to be a molten globule.

    Science.gov (United States)

    Rosen, Laura E; Connell, Katelyn B; Marqusee, Susan

    2014-10-14

    The molten globule, a conformational ensemble with significant secondary structure but only loosely packed tertiary structure, has been suggested to be a ubiquitous intermediate in protein folding. However, it is difficult to assess the tertiary packing of transiently populated species to evaluate this hypothesis. Escherichia coli RNase H is known to populate an intermediate before the rate-limiting barrier to folding that has long been thought to be a molten globule. We investigated this hypothesis by making mimics of the intermediate that are the ground-state conformation at equilibrium, using two approaches: a truncation to generate a fragment mimic of the intermediate, and selective destabilization of the native state using point mutations. Spectroscopic characterization and the response of the mimics to further mutation are consistent with studies on the transient kinetic intermediate, indicating that they model the early intermediate. Both mimics fold cooperatively and exhibit NMR spectra indicative of a closely packed conformation, in contrast to the hypothesis of molten tertiary packing. This result is important for understanding the nature of the subsequent rate-limiting barrier to folding and has implications for the assumption that many other proteins populate molten globule folding intermediates.

  9. Evidence for a differential contribution of early perceptual and late cognitive processes during encoding to episodic memory impairment in schizophrenia.

    Science.gov (United States)

    Green, Amity E; Fitzgerald, Paul B; Johnston, Patrick J; Nathan, Pradeep J; Kulkarni, Jayashri; Croft, Rodney J

    2017-08-01

    Schizophrenia is characterised by significant episodic memory impairment that is thought to be related to problems with encoding, however the neuro-functional mechanisms underlying these deficits are not well understood. The present study used a subsequent recognition memory paradigm and event-related potentials (ERPs) to investigate temporal aspects of episodic memory encoding deficits in schizophrenia. Electroencephalographic data was recorded in 24 patients and 19 healthy controls whilst participants categorised single words as pleasant/unpleasant. ERPs were generated to subsequently recognised versus unrecognised words on the basis of a forced-choice recognition memory task. Subsequent memory effects were examined with the late positive component (LPP). Group differences in N1, P2, N400 and LPP were examined for words correctly recognised. Patients performed more poorly than controls on the recognition task. During encoding patients had significantly reduced N400 and LPP amplitudes than controls. LPP amplitude correlated with task performance however amplitudes did not differ between patients and controls as a function of subsequent memory. No significant differences in N1 or P2 amplitude or latency were observed. The present results indicate that early sensory processes are intact and dysfunctional higher order cognitive processes during encoding are contributing to episodic memory impairments in schizophrenia.

  10. Molecular pathways involved in the early and late damage induced by testis ischemia: evidence for a rational pharmacological modulation.

    Science.gov (United States)

    Altavilla, D; Romeo, C; Squadrito, F; Marini, H; Morgia, G; Antonuccio, P; Minutoli, L

    2012-01-01

    Testicular torsion or torsion of the spermatic cord is a surgical emergency in which misdiagnosis and inappropriate treatment can lead to male infertility. Events occurring during testicular torsion and detorsion are representative of an ischemia-reperfusion injury observed in other organs. The two most important factors determining testicular damage are the degree of twisting and the early onset of a surgical treatment to counter-rotate both testis and spermatic cord for inducing reperfusion. The damage from reperfusion is more severe than that induced by ischemia and several mechanisms are implicated in the development of testicular damage following torsion and detorsion. However, these mechanisms have not yet been fully clarified and, as a consequence, there is still a strong need to identify specific pharmacological treatment to limit the damage triggered by the reperfusion procedures. Ischemia and reperfusion of testis result in elevated production of reactive oxygen species (ROS), activate mitogen activated protein kinases (MAPKs) and PPARβ/δ receptor, induce transcription factors and growth factors including NF-κB and VEGF, trigger apoptotic machinery and induce several inflammatory cytokines, including TNF-α and IL-1β . This pathological cascade is responsible for the testicular atrophy, decreased blood flow and impaired spermatogenesis. Several pharmacological approaches have been characterized as promising therapeutic agents for the management of testicular torsion and may be useful to ameliorate the sequel of this disease.

  11. Tropical anurans mature early and die young: Evidence from eight Afromontane Hyperolius species and a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Ulrich Sinsch

    Full Text Available Age- and size-related life-history traits of anuran amphibians are thought to vary systematically with latitude and altitude. Because the available data base is strongly biased towards temperate-zone species, we provide new estimates on eight afrotropical Reed Frog species. A meta-analysis of the demographic traits in 44 tropical anuran species aims to test for the predicted clinal variation and to contrast results with variation detected in temperate-zone species. The small-sized reed frogs reach sexual maturity during the first or second year of life, but longevity does not exceed three to four years. Latitudinal effects on demographic life-history traits are not detectable in tropical anurans, and altitudinal effects are limited to a slight size reduction at higher elevations. Common features of anuran life-history in the tropics are early sexual maturation at small size and low longevity resulting in low lifetime fecundity. This pattern contrasts with that found in temperate-zone anurans which mature later at larger size and grow considerably older yielding greater lifetime fecundity than in the tropics. Latitudinal and altitudinal contraction of the yearly activity period shape the evolution of life-history traits in the temperate region, while trait variation in the tropics seems to be driven by distinct, not yet identified selective forces.

  12. Pedogenic calcite as evidence for an early Holocene dry period in the San Francisco Bay area, California

    Science.gov (United States)

    Borchardt, G.; Lienkaemper, J.J.

    1999-01-01

    Rainfall at the site of Union City, California, during early Holocene time appears to have been about half that of today, 470 mm/yr. We base this conclusion on detailed descriptions and particle-size analyses of 12 soil profiles and 1:20 scale logs of the fluvial stratigraphy in two 100-m-long, 5-m-deep excavations dug perpendicular to the axis of an alluvial fan along the Hayward fault. Subsidence and right-lateral movement along the fault allowed an offset stream to produce a nearly continuous alluvial record documented by 35 14C ages on detrital charcoal. Bk (calcitic) horizons in paleosols developed in the fan suggest that a relatively dry climatic period occurred from 10 to 7 ka (calendar-corrected ages). The pedogenic calcite exists primarily as vertically oriented filaments and fine, cavernous nodules formed at ped intersections. Soils and paleosols formed before 10 ka or since 7 ka did not have Bk horizons. Bk horizons that were buried suddenly at 7 ka were overlain by leached zones averaging 41 ?? 3 cm thick - about half the current depth of leaching.

  13. Early Onset of Distress Disorders and High-School Dropout: Prospective Evidence From a National Cohort of Australian Adolescents.

    Science.gov (United States)

    Butterworth, Peter; Leach, Liana S

    2018-06-01

    Prior research examining whether depression and anxiety lead to high-school dropout has been limited by a reliance on retrospective reports, the assessment of mental health at a single point in time (often remote from the time of high-school exit), and the omission of important measures of the social and familial environment. The present study addressed these limitations by analyzing 8 waves of longitudinal data from a cohort of Australian adolescents (n = 1,057) in the Household, Income and Labor Dynamics in Australia (HILDA) Survey (2001-2008). Respondents were followed from the age of 15 years through completion of or exit from high school. Discrete-time survival analysis was used to assess whether the early experience of a distress disorder (indicated by scores dropout, after controlling for household and parental socioeconomic characteristics and for tobacco smoking and alcohol consumption. Adolescents with a prior distress disorder had twice the odds of high-school dropout compared with those without (odds ratio = 1.99, 95% confidence interval: 1.24, 3.17). This association was somewhat attenuated but remained significant in models including tobacco and alcohol consumption (odds ratio = 1.74, 95% confidence interval: 1.74; 1.09, 2.78). These results suggest that improving the mental health of high-school students may promote better educational outcomes.

  14. The contribution of short-term memory for serial order to early reading acquisition: evidence from a longitudinal study.

    Science.gov (United States)

    Martinez Perez, Trecy; Majerus, Steve; Poncelet, Martine

    2012-04-01

    Early reading acquisition skills have been linked to verbal short-term memory (STM) capacity. However, the nature of this relationship remains controversial because verbal STM, like reading acquisition, depends on the complexity of underlying phonological processing skills. This longitudinal study addressed the relation between STM and reading decoding acquisition by distinguishing between STM for item information and STM for order information based on recent studies showing that STM for item information, but not STM for order information, recruits underlying phonological representations. If there is a specific link between STM and reading decoding acquisition, STM for order information should be an independent predictor of reading decoding acquisition. Tasks maximizing STM for serial order or item information, measures of phonological abilities, and reading tests were administered to children followed from kindergarten through first grade. We observed that order STM capacity, but not item STM capacity, predicted independent variance in reading decoding abilities 1 year later. These results highlight the specific role of STM for order in reading decoding acquisition and argue for a causal role of order STM capacity in reading acquisition. Mechanisms relating STM for order information and reading acquisition are discussed. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. The use of fan scrapers: Microwear evidence from Late Pottery Neolithic and Early Bronze Age, Ein Zippori, Israel

    Directory of Open Access Journals (Sweden)

    Richard W. Yerkes

    2016-09-01

    Full Text Available The results of a microwear analysis of samples of fan scrapers and fan scrapers spalls from late Pottery Neolithic (PN and Early Bronze Age (EBA occupation layers at Ein Zippori, Lower Galilee, Israel are presented. The goal of the microwear analysis was to determine the function of the fan scrapers and compare the visible usewear on the scrapers found in late PN and EBA lithic assemblages. The results indicate that during both periods most of the fan scrapers were used to skin and butcher animals, while some were also used for hide processing and bone working. The working edges of the fan scrapers had sharp, moderate, or steep edge-angles, and different edges were used for different tasks. Edges with microwear from scraping meat, bone, and hides (including some hides that may have been treated with abrasives had steep edge-angles, while there were moderate or sharp edge-angles on the edges of fan scrapers used for cutting. Two sub-types of fan scrapers were identified, flat cortex fan scrapers (FCFS, and cortical fan scrapers (CFS with convex dorsal faces. The CFS were abundant in PN contexts, while the FCFS were more common in EBA layers. However both of the sub-types had similar microwear traces.

  16. New evidence on the origin of non-spinose pitted-cancellate species of the early Danian planktonic foraminifera

    Science.gov (United States)

    Arenillas, Ignacio; Arz, Jose Antonio

    2013-06-01

    Intermediate forms identified in some of the most continuous lower Danian sections allow a better understanding of the origin and evolution of pitted (Globanomalina) and cancellate (Praemurica) planktonic foraminifera. Both Globanomalina and Praemurica are part of a major Paleocene lineage, namely the "non-spinose lineage", which started to diverge in the early Danian. Transitional specimens strongly suggest the evolution from Parvularugoglobigerina to Globanomalina, and then to Praemurica. These evolutionary turnovers were quite rapid (probably lasting less than 10 kyr), and seem to have begun in the time equivalent of the lower part of the E. simplicissima Subzone, namely the middle part of the standard Zone Pa. The initial evolutionary trends within this non-spinose lineage were the increase of test size and lip thickness, and the evolution from tiny pore-murals to large pore-pits, and from smooth to pitted and finally cancellate walls. Biostratigraphic data suggest that evolution of the wall texture preceded the morphological evolution within each genus. The oldest species of both Globanomalina and Praemurica, namely G. archeocompressa and Pr. taurica, initially retained the external morphology of the ancestral Parvularugoglobigerina eugubina. Since their divergence, Globanomalina and Praemurica followed a separate evolutionary path, evolving into morphologically different species.

  17. Gene expression profiling for guiding adjuvant chemotherapy decisions in women with early breast cancer: an evidence-based and economic analysis.

    Science.gov (United States)

    2010-01-01

    In February 2010, the Medical Advisory Secretariat (MAS) began work on evidence-based reviews of published literature surrounding three pharmacogenomic tests. This project came about when Cancer Care Ontario (CCO) asked MAS to provide evidence-based analyses on the effectiveness and cost-effectiveness of three oncology pharmacogenomic tests currently in use in Ontario.Evidence-based analyses have been prepared for each of these technologies. These have been completed in conjunction with internal and external stakeholders, including a Provincial Expert Panel on Pharmacogenomics (PEPP). Within the PEPP, subgroup committees were developed for each disease area. For each technology, an economic analysis was also completed by the Toronto Health Economics and Technology Assessment Collaborative (THETA) and is summarized within the reports.THE FOLLOWING REPORTS CAN BE PUBLICLY ACCESSED AT THE MAS WEBSITE AT: www.health.gov.on.ca/mas or at www.health.gov.on.ca/english/providers/program/mas/mas_about.htmlGENE EXPRESSION PROFILING FOR GUIDING ADJUVANT CHEMOTHERAPY DECISIONS IN WOMEN WITH EARLY BREAST CANCER: An Evidence-Based and Economic AnalysisEpidermal Growth Factor Receptor Mutation (EGFR) Testing for Prediction of Response to EGFR-Targeting Tyrosine Kinase Inhibitor (TKI) Drugs in Patients with Advanced Non-Small-Cell Lung Cancer: An Evidence-Based and Ecopnomic AnalysisK-RAS testing in Treatment Decisions for Advanced Colorectal Cancer: an Evidence-Based and Economic Analysis To review and synthesize the available evidence regarding the laboratory performance, prognostic value, and predictive value of Oncotype-DX for the target population. CONDITION AND TARGET POPULATION The target population of this review is women with newly diagnosed early stage (stage I-IIIa) invasive breast cancer that is estrogen-receptor (ER) positive and/or progesterone-receptor (PR) positive. Much of this review, however, is relevant for women with early stage (I and II) invasive breast

  18. Impedance-matching hearing in Paleozoic reptiles: evidence of advanced sensory perception at an early stage of amniote evolution.

    Directory of Open Access Journals (Sweden)

    Johannes Müller

    Full Text Available BACKGROUND: Insights into the onset of evolutionary novelties are key to the understanding of amniote origins and diversification. The possession of an impedance-matching tympanic middle ear is characteristic of all terrestrial vertebrates with a sophisticated hearing sense and an adaptively important feature of many modern terrestrial vertebrates. Whereas tympanic ears seem to have evolved multiple times within tetrapods, especially among crown-group members such as frogs, mammals, squamates, turtles, crocodiles, and birds, the presence of true tympanic ears has never been recorded in a Paleozoic amniote, suggesting they evolved fairly recently in amniote history. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we performed a morphological examination and a phylogenetic analysis of poorly known parareptiles from the Middle Permian of the Mezen River Basin in Russia. We recovered a well-supported clade that is characterized by a unique cheek morphology indicative of a tympanum stretching across large parts of the temporal region to an extent not seen in other amniotes, fossil or extant, and a braincase specialized in showing modifications clearly related to an increase in auditory function, unlike the braincase of any other Paleozoic tetrapod. In addition, we estimated the ratio of the tympanum area relative to the stapedial footplate for the basalmost taxon of the clade, which, at 23:1, is in close correspondence to that of modern amniotes capable of efficient impedance-matching hearing. CONCLUSIONS/SIGNIFICANCE: Using modern amniotes as analogues, the possession of an impedance-matching middle ear in these parareptiles suggests unique ecological adaptations potentially related to living in dim-light environments. More importantly, our results demonstrate that already at an early stage of amniote diversification, and prior to the Permo-Triassic extinction event, the complexity of terrestrial vertebrate ecosystems had reached a level that

  19. Early sensory cortex is activated in the absence of explicit input during crossmodal item retrieval: evidence from MEG.

    Science.gov (United States)

    Pillai, Ajay S; Gilbert, Jessica R; Horwitz, Barry

    2013-02-01

    Crossmodal associations form a fundamental aspect of our daily lives. In this study we investigated the neural correlates of crossmodal association in early sensory cortices using magnetoencephalography (MEG). We used a paired associate recognition paradigm in which subjects were tested after multiple training sessions over a span of four weeks. Subjects had to learn 12 abstract, nonlinguistic, pairs of auditory and visual objects that consisted of crossmodal (visual-auditory, VA; auditory-visual, AV) and unimodal (visual-visual, VV; auditory-auditory, AA) paired items. Visual objects included abstract, non-nameable, fractal-like images, and auditory objects included abstract tone sequences. During scanning, subjects were shown the first item of a pair (S1), followed by a delay, then the simultaneous presentation of a visual and auditory stimulus (S2). Subjects were instructed to indicate whether either of the S2 stimuli contained the correct paired associate of S1. Synthetic aperture magnetometry (SAMspm), a minimum variance beamformer, was then used to assess source power differences between the crossmodal conditions and their corresponding unimodal conditions (i.e., AV-AA and VA-VV) in the beta (15-30 Hz) and low gamma frequencies (31-54 Hz) during the S1 period. We found greater power during S1 in the corresponding modality-specific association areas for crossmodal compared with unimodal stimuli. Thus, even in the absence of explicit sensory input, the retrieval of well-learned, crossmodal pairs activate sensory areas associated with the corresponding modality. These findings support theories which posit that modality-specific regions of cortex are involved in the storage and retrieval of sensory-specific items from long-term memory. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Early oestrogens in shaping reproductive networks: evidence for a potential organisational role of oestradiol in female brain development.

    Science.gov (United States)

    Bakker, J; Brock, O

    2010-07-01

    A central tenet of contemporary theories on mammalian brain and behavioural sexual differentiation is that an organisational action of testosterone, secreted by the male's testes, controls male-typical aspects of brain and behavioural development, whereas no active perinatal sex hormone signalling is required for female-typical sexual differentiation. Furthermore, the available evidence suggests that many, although not all, of the perinatal organisational actions of testosterone on the development of the male brain result from the cellular effects of oestradiol formed via neural aromatisation of testosterone. However, a default developmental programme for the female brain has been criticised. Indeed, we review new results obtained in aromatase knockout mice indicating that oestradiol actively contributes to the differentiation of female-typical aspects of brain and behavioural sexual differentiation. Furthermore, we propose that male-typical neural and behavioural differentiation occurs prenatally in genetic males under the influence of oestradiol, which is avoided in foetal genetic females by the neuroprotective actions of alpha-fetoprotein, whereas female-typical neural and behavioural differentiation normally occurs postnatally in genetic females under the influence of oestradiol that is presumably produced by the ovaries.

  1. Conceptual plural information is used to guide early parsing decisions: Evidence from garden-path sentences with reciprocal verbs.

    Science.gov (United States)

    Patson, Nikole D; Ferreira, Fernanda

    2009-05-01

    In three eyetracking studies, we investigated the role of conceptual plurality in initial parsing decisions in temporarily ambiguous sentences with reciprocal verbs (e.g., While the lovers kissed the baby played alone). We varied the subject of the first clause using three types of plural noun phrases: conjoined noun phrases (the bride and the groom), plural definite descriptions (the lovers), and numerically quantified noun phrases (the two lovers). We found no evidence for garden-path effects when the subject was conjoined (Ferreira & McClure, 1997), but traditional garden-path effects were found with the other plural noun phrases. In addition, we tested plural anaphors that had a plural antecedent present in the discourse. We found that when the antecedent was conjoined, garden-path effects were absent compared to cases in which the antecedent was a plural definite description. Our results indicate that the parser is sensitive to the conceptual representation of a plural constituent. In particular, it appears that a Complex Reference Object (Moxey et al., 2004) automatically activates a reciprocal reading of a reciprocal verb.

  2. Evidence for ephemeral middle Eocene to early Oligocene Greenland glacial ice and pan-Arctic sea ice.

    Science.gov (United States)

    Tripati, Aradhna; Darby, Dennis

    2018-03-12

    Earth's modern climate is defined by the presence of ice at both poles, but that ice is now disappearing. Therefore understanding the origin and causes of polar ice stability is more critical than ever. Here we provide novel geochemical data that constrain past dynamics of glacial ice on Greenland and Arctic sea ice. Based on accurate source determinations of individual ice-rafted Fe-oxide grains, we find evidence for episodic glaciation of distinct source regions on Greenland as far-ranging as ~68°N and ~80°N synchronous with ice-rafting from circum-Arctic sources, beginning in the middle Eocene. Glacial intervals broadly coincide with reduced CO 2 , with a potential threshold for glacial ice stability near ~500 p.p.m.v. The middle Eocene represents the Cenozoic onset of a dynamic cryosphere, with ice in both hemispheres during transient glacials and substantial regional climate heterogeneity. A more stable cryosphere developed at the Eocene-Oligocene transition, and is now threatened by anthropogenic emissions.

  3. Evolution of GHF5 endoglucanase gene structure in plant-parasitic nematodes: no evidence for an early domain shuffling event.

    Science.gov (United States)

    Kyndt, Tina; Haegeman, Annelies; Gheysen, Godelieve

    2008-11-03

    the whole gene cassette, i.e. the GHF5 catalytic domain and the CBM2, rather than that it evolved by domain shuffling. Our evolutionary model for the gene structure in PPN GHF5 endoglucanases implies the occurrence of an early duplication event, and more recent gene duplications at genus or species level.

  4. Evolution of GHF5 endoglucanase gene structure in plant-parasitic nematodes: no evidence for an early domain shuffling event

    Directory of Open Access Journals (Sweden)

    Gheysen Godelieve

    2008-11-01

    PPN GHF5 endoglucanase gene most probably consisted of the whole gene cassette, i.e. the GHF5 catalytic domain and the CBM2, rather than that it evolved by domain shuffling. Our evolutionary model for the gene structure in PPN GHF5 endoglucanases implies the occurrence of an early duplication event, and more recent gene duplications at genus or species level.

  5. Late Noachian/Early Hesperian Ridge Network in Nili Fossae: Evidence for Water-Saturated Near-Surface Crust

    Science.gov (United States)

    Mustard, J. F.; Pascuzzo, A.

    2017-12-01

    The region north of the contact between Syrtis Major and the Isidis Basin is populated by thousands of ridges 100s of meters in length, up to a few 10s of meters high and 15-50 meters wide. The resistant ridges are being exhumed from weak early Noachian smectite-bearing host rocks. Hypotheses for the formation include igneous intrusion or fill, impact-induced breccia dikes and chemical alteration of pre-existing fracture planes or mineralized fracture planes through groundwater circulation (our preferred mode of formation). Mineralogic interpretations of visible-near infrared reflectance spectra from the CRISM instrument on MRO may be critical in interpreting the formation process. While most of the ridges are at the limit of CRISM's spatial resolution of 18 m/pixel, CRISM has a special observing mode which can increase the resolution in the along track observing (ATO) direction by a factor of 2-3 (e.g. 6 m). Using a combination of full resolution and one ATO observation, we have analyzed well-exposed ridges in the Nili Fossae region. Ridges are commonly exposed from beneath a distinctive mafic capping rock rich in olivine and variably altered to magnesite. Many of the ridges exhibit weaker smectite absorptions near 1.9 and 2.3 µm compared to the host rock but no additional spectral features are observed. One cause for weaker absorptions is grain size (i.e. solid rock shows weaker absorptions than its powdered equivalent). Alternatively the presence of a spectrally neutral cementing compound or mineral like quartz could lead to weaker features. Timing of ridge formation is constrained by two key stratigraphic makers. First the ridges were likely formed after the Isidis basin-forming event, 3.9 Ga, because many are observed between the 1st and 2nd rings of the basin structure and would not have survived the impact event otherwise. Second the ridges are exhumed from beneath a distinctive olivine-rich mafic cap unit with its emplacement dated to between the Isidis

  6. Evaluation of Blood-Based Antibody Rapid Testing for HIV Early Therapy: A Meta-Analysis of the Evidence

    Directory of Open Access Journals (Sweden)

    Xiaojie Huang

    2018-06-01

    for substituting RT for WB. Blood-based rapid HIV tests have comparable sensitivity and specificity to WB for HIV early therapy.

  7. Evidence for ancient atmospheric xenon in Archean rocks and implications for the early evolution of the atmosphere

    Science.gov (United States)

    Pujol, M.; Marty, B.; Burnard, P.; Hofmann, A.

    2012-12-01

    The initial atmospheric xenon isotopic composition has been much debated over the last 4 decades. A Non radiogenic Earth Atmospheric xenon (NEA-Xe) composition has been proposed to be the best estimate of the initial signature ([1]). NEA-Xe consists of modern atmospheric Xe without fission (131-136Xe) or radioactive decay (129Xe) products. However, the isotope composition of such non-radiogenic xenon is very different to that of potential cosmochemical precursors such as solar or meteoritic Xe, as it is mass-fractionated by up to 3-4 % per amu relative to the potential precursors, and it is also elementally depleted relative to other noble gases. Because the Xe isotopic composition of the Archean appears to be intermediate between that of these cosmochemical end-members and that of the modern atmosphere, we argued that isotopic fractionation of atmospheric xenon did not occur early in Earth's history by hydrodynamic escape, as postulated by all other models ([1], [2], [3]), but instead was a continuous, long term process that lasted during at least the Hadean and Archean eons. Taken at face value, the decrease of the Xe isotopic fractionation from 1.6-2.1 % amu-1 3.5 Ga ago ([4]) to 1 % amu-1 3.0 Ga ago (Ar-Ar age in fluid inclusions trapped in quartz from the same Dresser Formation, [5]) could reflect a secular variation of the atmospheric Xe signature. Nevertheless, up until now, all data showing an isotopic mass fractionation have been measured in rocks and fluids from the same formation (Dresser Formation, Western Australia, aged 3.5 Ga), and have yet to be confirmed in rocks from different locations. In order to better constrain xenon isotopic fractionation of the atmosphere through time, we decided to analyze barites from different ages, geological environments and metamorphism grade. We started this study with barite from the Fig Tree Formation (South Africa, aged 3.26 Ga). This barite was sampled in old mines so have negligible modern exposure time. It is

  8. Physical health, lifestyle beliefs and behaviors, and mental health of entering graduate health professional students: Evidence to support screening and early intervention.

    Science.gov (United States)

    Mazurek Melnyk, Bernadette; Slevin, Caitlin; Militello, Lisa; Hoying, Jacqueline; Teall, Alice; McGovern, Colleen

    2016-04-01

    Little is known about the physical health, lifestyle beliefs and behaviors, and mental health among first-year health professional graduate students. Therefore, the purpose of this study was to describe these attributes as well as to explore the relationships among them. A descriptive correlational study was conducted on the baseline data from a wellness onboarding intervention study with 93 health sciences students from seven different colleges within a large public land grant university in the Midwest United States. Nearly 40% of the sample was overweight/obese, and 19% of students had elevated total cholesterol levels. Only 44% met the recommended 30 min of exercise 5 days per week. Forty-one percent reported elevated depressive symptoms and 28% had elevated anxiety. Four students reported suicidal ideation. Inverse relationships existed among depression/anxiety and healthy lifestyle beliefs/behaviors. Students entering health professional schools are at high risk for depression, anxiety, and unhealthy behaviors, which could be averted through screening and early evidence-based interventions. Assessing the physical health, lifestyle behaviors, and mental health of first-year health sciences professional students is important to identify health problems and modifiable at-risk behaviors so that early interventions can be implemented to improve outcomes. ©2016 American Association of Nurse Practitioners.

  9. Glial Alterations From Early to Late Stages in a Model of Alzheimer’s Disease: Evidence of Autophagy Involvement in Aβ Internalization

    Science.gov (United States)

    Pomilio, Carlos; Pavia, Patricio; Gorojod, Roxana Mayra; Vinuesa, Angeles; Alaimo, Agustina; Galvan, Veronica; Kotler, Monica Lidia; Beauquis, Juan; Saravia, Flavia

    2017-01-01

    Alzheimer’s disease (AD) is a progressive neurodegenerative disease without effective therapy. Brain amyloid deposits are classical histopathological hallmarks that generate an inflammatory reaction affecting neuronal and glial function. The identification of early cell responses and of brain areas involved could help to design new successful treatments. Hence, we studied early alterations of hippocampal glia and their progression during the neuropathology in PDAPP-J20 transgenic mice, AD model, at 3, 9, and 15 months (m) of age. At 3 m, before deposits formation, microglial Iba1 + cells from transgenic mice already exhibited signs of activation and larger soma size in the hilus, alterations appearing later on stratum radiatum. Iba1 immunohistochemistry revealed increased cell density and immunoreactive area in PDAPP mice from 9 m onward selectively in the hilus, in coincidence with prominent amyloid Congo red + deposition. At pre-plaque stages, GFAP+ astroglia showed density alterations while, at an advanced age, the presence of deposits was associated with important glial volume changes and apparently being intimately involved in amyloid degradation. Astrocytes around plaques were strongly labeled for LC3 until 15 m in Tg mice, suggestive of increased autophagic flux. Moreover, β-Amyloid fibrils internalization by astrocytes in in vitro conditions was dependent on autophagy. Co-localization of Iba1 with ubiquitin or p62 was exclusively found in microglia contacting deposits from 9 m onward, suggesting torpid autophagy. Our work characterizes glial changes at early stages of the disease in PDAPP-J20 mice, focusing on the hilus as an especially susceptible hippocampal subfield, and provides evidence that glial autophagy could play a role in amyloid processing at advanced stages. PMID:26235241

  10. Speleothem evidence for the greening of the Sahara and its implications for the early human dispersal out of sub-Saharan Africa

    Science.gov (United States)

    El-Shenawy, Mohammed I.; Kim, Sang-Tae; Schwarcz, Henry P.; Asmerom, Yemane; Polyak, Victor J.

    2018-05-01

    Although there is a consensus that there were wet periods (greening events) in the Sahara in the past, the spatial extent and the timing of these greening events are still in dispute, yet critical to our understanding of the early human dispersal out of Africa. Our U-series dates of speleothems from the Northeastern Sahara (Wadi Sannur cave, Egypt) reveal that the periods of speleothem growth were brief and restricted to the interglacial Marine Isotope Stages MIS 5.5, MIS 7.3, and the early MIS 9 with a remarkable absence of the Holocene deposition of speleothems. These growth periods of Wadi Sannur cave speleothems correspond to periods of high rainfall and spread of vegetation (green Sahara). Distinct low δ18O values of speleothems indicate a distal moisture source that we interpret to be the Atlantic Ocean. These two lines of evidence from the Wadi Sannur speleothems thus suggest that maximal northward shifts in the West African monsoon system occurred during the growth periods of the speleothems, leading to greening of the Sahara, facilitating human migration into Eurasia. The periods of speleothem growth at Wadi Sannur cave are contemporaneous with important archeological events: (1) the earliest occurrence of the Middle Stone Age assemblages and Homo sapiens in North Africa (Jebel Irhoud), suggesting wide spread of greening conditions over the East-West transect of the Sahara, (2) the sharp technological break between the Acheulo-Yabrudian and the Mousterian industries, and (3) the arrival of Homo sapiens in Levant, indicating a key role of the Sahara route in early human dispersal out of Africa.

  11. Inferred Early Permian Arc Rifting in Bogda Mountain, Southernmost of the Central Asia Orogenic Belt: Evidence from a Peperite Bearing Volcano-Sedimentary Succession

    Science.gov (United States)

    Memtimin, M.; Guo, Z.

    2017-12-01

    Late Paleozoic tectonic history, especially Carboniferous-Permian periods, of the Central Asia Orogenic Belt (CAOB) is considered to be the turning point for the termination of terrane amalgamation and closure of the Paleoasian Ocean. However, the debate about the paleoenvironment and tectonic setting of the region during the period is still not resolved. In this study, we report a set of volcano-sedimentary sequence in the Bogda Mountain of the southernmost of CAOB, which is associated with contemporaneous subaqueous emplacement of and interaction between mafic lava and carbonate sediments. The succession contains four distinct facies including closely packed pillow basalts, pillow basalts with interstitial materials, hyaloclastites and peperites. We discuss their formation and emplacement mechanism, interaction between hot magma-water/unconsolidated sediments and thermal metamorphism during the interaction. Textural features of the sequence, especially hyaloclastites and peperites, provide clear evidence for in situ autofragmentation of lava flows, synvolcanic sedimentation of carbonates, fuel coolant interaction when hot magma bulldozed into wet unconsolidated sediments, and represent autochthonous origin of the succession. Lateral transition of the lithofacies indicate a progressively deepening subaqueous environment, resembling a stepwise evolution from early stage of volcanic intrusion with lower lava flux in shallower water level to increasingly subsiding basin with more lava flux in greater depth. Previous studies determined that the mafic magma was intruded around the Carboniferous-Permian boundary ( 300Ma), and geochemical studies showed the magma was originated from dry depleted mantle with little crustal contamination. Nevertheless, the succession was thought to be fault related allochthones formation which was transferred in as part of a Carboniferous intraplate arc. Combining our findings with the previous study results, we propose a new model to

  12. The long-term impact of early life pain on adult responses to anxiety and stress: Historical perspectives and empirical evidence.

    Science.gov (United States)

    Victoria, Nicole C; Murphy, Anne Z

    2016-01-01

    Approximately 1 in 6 infants are born prematurely each year. Typically, these infants spend 25 days in the Neonatal Intensive Care Unit (NICU) where they experience 10-18 painful and inflammatory procedures each day. Remarkably, pre-emptive analgesics and/or anesthesia are administered less than 25% of the time. Unalleviated pain during the perinatal period is associated with permanent decreases in pain sensitivity, blunted cortisol responses and high rates of neuropsychiatric disorders. To date, the mechanism(s) by which these long-term changes in stress and pain behavior occur, and whether such alterations can be prevented by appropriate analgesia at the time of insult, remains unclear. Work in our lab using a rodent model of early life pain suggests that inflammatory pain experienced on the day of birth blunts adult responses to stress- and pain-provoking stimuli, and dysregulates the hypothalamic pituitary adrenal (HPA) axis in part through a permanent upregulation in central endogenous opioid tone. This review focuses on the long-term impact of neonatal inflammatory pain on adult anxiety- and stress-related responses, and underlying neuroanatomical changes in the context of endogenous pain control and the HPA axis. These two systems are in a state of exaggerated developmental plasticity early in postnatal life, and work in concert to respond to noxious or aversive stimuli. We present empirical evidence from animal and clinical studies, and discuss historical perspectives underlying the lack of analgesia/anesthetic use for early life pain in the modern NICU. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. A review of evidence-based early intervention for behavioural problems in children with autism spectrum disorder: the core components of effective programs, child-focused interventions and comprehensive treatment models.

    Science.gov (United States)

    Tonge, Bruce J; Bull, Kerry; Brereton, Avril; Wilson, Rebecca

    2014-03-01

    This article reviews recent evidence and other earlier relevant articles regarding early intervention studies for children with autism spectrum disorder (ASD). There is a well-established body of empirical evidence for the effectiveness of Early Intensive Behavioural Intervention (EIBI) with young children with ASD. The importance of parent skills training, education and positive behaviour support is also a key factor in influencing outcomes. Drug treatment is of short-term benefit for disruptive behaviour but long-term outcome and metabolic side-effects have not been studied. Few studies have measured the long-term value and effectiveness of early intervention treatments, and currently there are no articles published on effects into adulthood of such treatments. Such research would indicate whether early intervention results in reduced reliance on health services into adulthood.

  14. Development of theory-based knowledge translation interventions to facilitate the implementation of evidence-based guidelines on the early management of adults with traumatic spinal cord injury.

    Science.gov (United States)

    Bérubé, Mélanie; Albert, Martin; Chauny, Jean-Marc; Contandriopoulos, Damien; DuSablon, Anne; Lacroix, Sébastien; Gagné, Annick; Laflamme, Élise; Boutin, Nathalie; Delisle, Stéphane; Pauzé, Anne-Marie; MacThiong, Jean-Marc

    2015-12-01

    Optimal, early management following a spinal cord injury (SCI) can limit individuals' disabilities and costs related to their care. Several knowledge syntheses were recently published to guide health care professionals with regard to early interventions in SCI patients. However, no knowledge translation (KT) intervention, selected according to a behaviour change theory, has been proposed to facilitate the use of SCI guidelines in an acute care setting. To develop theory-informed KT interventions to promote the application of evidence-based recommendations on the acute care management of SCI patients. The first four phases of the knowledge-to-action model were used to establish the study design. Knowledge selection was based on the Grading of Recommendations Assessment, Development and Evaluation system. Knowledge adaptation to the local context was sourced from the ADAPTE process. The theoretical domains framework oriented the selection and development of the interventions based on an assessment of barriers and enablers to knowledge application. Twenty-nine recommendations were chosen and operationalized in measurable clinical indicators. Barriers related to knowledge, skills, perceived capacities, beliefs about consequences, social influences, and the environmental context and resources theoretical domains were identified. The mapping of behaviour change techniques associated with those barriers led to the development of an online educational curriculum, interdisciplinary clinical pathways as well as policies and procedures. This research project allowed us developing KT interventions according to a thorough behavioural change methodology. Exposure to the generated interventions will support health care professionals in providing the best care to SCI patients. © 2015 John Wiley & Sons, Ltd.

  15. Phosphogenesis in the 2460 and 2728 million-year-old banded iron formations as evidence for biological cycling of phosphate in the early biosphere.

    Science.gov (United States)

    Li, Yi-Liang; Sun, Si; Chan, Lung S

    2012-01-01

    The banded iron formation deposited during the first 2 billion years of Earth's history holds the key to understanding the interplay between the geosphere and the early biosphere at large geological timescales. The earliest ore-scale phosphorite depositions formed almost at ∼2.0-2.2 billion years ago bear evidence for the earliest bloom of aerobic life. The cycling of nutrient phosphorus and how it constrained primary productivity in the anaerobic world of Archean-Palaeoproterozoic eons are still open questions. The controversy centers about whether the precipitation of ultrafine ferric oxyhydroxide due to the microbial Fe(II) oxidation in oceans earlier than 1.9 billion years substantially sequestrated phosphate, and whether this process significantly limited the primary productivity of the early biosphere. In this study, we report apatite radial flowers of a few micrometers in the 2728 million-year-old Abitibi banded iron formation and the 2460 million-year-old Kuruman banded iron formation and their similarities to those in the 535 million-year-old Lower Cambrian phosphorite. The lithology of the 535 Million-year-old phosphorite as a biosignature bears abundant biomarkers that reveal the possible similar biogeochemical cycling of phosphorus in the Later Archean and Palaeoproterozoic oceans. These apatite radial flowers represent the primary precipitation of phosphate derived from the phytoplankton blooms in the euphotic zones of Neoarchean and Palaoeproterozoic oceans. The unbiased distributions of the apatite radial flowers within sub-millimeter bands do not support the idea of an Archean Crisis of Phosphate. This is the first report of the microbial mediated mineralization of phosphorus before the Great Oxidation Event when the whole biosphere was still dominated by anaerobic microorganisms.

  16. Transportability of an Evidence-Based Early Childhood Intervention in a Low-Income African Country: Results of a Cluster Randomized Controlled Study.

    Science.gov (United States)

    Huang, Keng-Yen; Nakigudde, Janet; Rhule, Dana; Gumikiriza-Onoria, Joy Louise; Abura, Gloria; Kolawole, Bukky; Ndyanabangi, Sheila; Kim, Sharon; Seidman, Edward; Ogedegbe, Gbenga; Brotman, Laurie Miller

    2017-11-01

    Children in Sub-Saharan Africa (SSA) are burdened by significant unmet mental health needs. Despite the successes of numerous school-based interventions for promoting child mental health, most evidence-based interventions (EBIs) are not available in SSA. This study investigated the implementation quality and effectiveness of one component of an EBI from a developed country (USA) in a SSA country (Uganda). The EBI component, Professional Development, was provided by trained Ugandan mental health professionals to Ugandan primary school teachers. It included large-group experiential training and small-group coaching to introduce and support a range of evidence-based practices (EBPs) to create nurturing and predictable classroom experiences. The study was guided by the Consolidated Framework for Implementation Research, the Teacher Training Implementation Model, and the RE-AIM evaluation framework. Effectiveness outcomes were studied using a cluster randomized design, in which 10 schools were randomized to intervention and wait-list control conditions. A total of 79 early childhood teachers participated. Teacher knowledge and the use of EBPs were assessed at baseline and immediately post-intervention (4-5 months later). A sample of 154 parents was randomly selected to report on child behavior at baseline and post-intervention. Linear mixed effect modeling was applied to examine effectiveness outcomes. Findings support the feasibility of training Ugandan mental health professionals to provide Professional Development for Ugandan teachers. Professional Development was delivered with high levels of fidelity and resulted in improved teacher EBP knowledge and the use of EBPs in the classroom, and child social competence.

  17. 42,000-year-old worked and pigment-stained Nautilus shell from Jerimalai (Timor-Leste): Evidence for an early coastal adaptation in ISEA.

    Science.gov (United States)

    Langley, Michelle C; O'Connor, Sue; Piotto, Elena

    2016-08-01

    In this paper, we describe worked and pigment-stained Nautilus shell artefacts recovered from Jerimalai, Timor-Leste. Two of these artefacts come from contexts dating to between 38,000 and 42,000 cal. BP (calibrated years before present), and exhibit manufacturing traces (drilling, pressure flaking, grinding), as well as red colourant staining. Through describing more complete Nautilus shell ornaments from younger levels from this same site (>15,900, 9500, and 5000 cal. BP), we demonstrate that those dating to the initial occupation period of Jerimalai are of anthropogenic origin. The identification of such early shell working examples of pelagic shell in Island Southeast Asia not only adds to our growing understanding of the importance of marine resources to the earliest modern human communities in this region, but also indicates that a remarkably enduring shell working tradition was enacted in this area of the globe. Additionally, these artefacts provide the first material culture evidence that the inhabitants of Jerimalai were not only exploiting coastal resources for their nutritional requirements, but also incorporating these materials into their social technologies, and by extension, their social systems. In other words, we argue that the people of Jerimalai were already practicing a developed coastal adaptation by at least 42,000 cal. BP. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. The Early Diagnosis of Boys and Girls in Academic Risk Using the Perceptual-Motor Diagnostic System: A Longitudinal Retrospective Study of Evidences of its Effectiveness

    Directory of Open Access Journals (Sweden)

    Emmanuel Herrera-González

    2015-09-01

    Full Text Available The main objective in this study is to evidence the efficiency of the Peques System as a useful tool to diagnose, at an early stage, possible difficulties which will affect the academic performance. In a 3-year longitudinal study, the Perceptual-Motor Diagnostic System (Peques was applied to a sample of 149 participants (77 boys and 72 girls, who were beginning preschool education. Peques classified 38 children with a high risk to lose a year at primary school level. After a three-year follow-up (first primary school level, it was determined that 23 of the 127 who remained in the study (18%, had failed the first, second or third school year. From the high-risk group diagnosed by the Peques System, an 83% indeed lost a school year. These boys and girls had difficulties in different aspects, such as their information processing capacity, motor development, corporal image, Gestalt development and corporal coordination. We concluded that Peques System was able to predict the academic failure in the primary school level, based on the perceptual-motor development reached at preschool level. Further, based on this experience it is recommended to pay special attention to perceptual-motor development, since it plays a basic role in the academic success of boys and girls.

  19. Early childbearing, human capital attainment and mortality risk: Evidence from a longitudinal demographic surveillance area in rural-KwaZulu-Natal, South Africa

    Science.gov (United States)

    Ardington, Cally; Menendez, Alicia; Mutevedzi, Tinofa

    2014-01-01

    Using a rich longitudinal dataset, we examine the relationship between teen fertility and both subsequent educational outcomes and HIV related mortality risk in rural South Africa. Human capital deficits among teen mothers are large and significant, with earlier births associated with greater deficits. In contrast to many other studies from developed countries, we find no clear evidence of selectivity into teen childbearing in either schooling trajectories or pre-fertility household characteristics. Enrolment rates among teen mothers only begin to drop in the period immediately preceding the birth and future teen mothers are not behind in their schooling relative to other girls. Older teen mothers and those further ahead in school for their age pre-birth are more likely to continue schooling after the birth. In addition to adolescents’ higher biological vulnerability to HIV infection, pregnancy also appears to increase the risk of contracting HIV. Following women over an extended period, we document a higher HIV related mortality risk for teen mothers that cannot be explained by household characteristics in early adulthood. Controlling for age at sexual debut, we find that teen mothers report lower condom use and older partners than other sexually active adolescents. PMID:26028690

  20. One-pot synthesis of amino acid precursors with insoluble organic matter in planetesimals with aqueous activity

    Science.gov (United States)

    Kebukawa, Yoko; Chan, Queenie H. S.; Tachibana, Shogo; Kobayashi, Kensei; Zolensky, Michael E.

    2017-01-01

    The exogenous delivery of organic molecules could have played an important role in the emergence of life on the early Earth. Carbonaceous chondrites are known to contain indigenous amino acids as well as various organic compounds and complex macromolecular materials, such as the so-called insoluble organic matter (IOM), but the origins of the organic matter are still subject to debate. We report that the water-soluble amino acid precursors are synthesized from formaldehyde, glycolaldehyde, and ammonia with the presence of liquid water, simultaneously with macromolecular organic solids similar to the chondritic IOM. Amino acid products from hydrothermal experiments after acid hydrolysis include α-, β-, and γ-amino acids up to five carbons, for which relative abundances are similar to those extracted from carbonaceous chondrites. One-pot aqueous processing from simple ubiquitous molecules can thus produce a wide variety of meteoritic organic matter from amino acid precursors to macromolecular IOM in chondrite parent bodies. PMID:28345041

  1. Characterization of early follicular cDNA library suggests evidence for genetic polymorphisms in the inbred strain C108 of Bombyx mori.

    Science.gov (United States)

    Mills, D R; Goldsmith, M R

    2000-04-01

    Recent work towards the completion of a saturated molecular genetic linkage map for the lepidopteran silkworm, Bombyx mori (n = 28), has provided evidence for existing polymorphisms in the inbred strain C108. Two inbred parental strains, p50 and C108, were crossed to produce the F1 (P/C) hybrid offspring. The populations used in this project were comprised of a combination of 29 F2 (F1 x F1) and 31 reciprocal backcross (P/C x C/C, P/C x P/P) progeny. All restriction fragment length polymorphisms (RFLPs) for the initial analysis were hybridized with anonymous probes derived from a random early follicular cDNA (Rcf) library from Bombyx. A total of 19 Rcf probes were selected as showing scorable codominant polymorphic patterns when screened against F2 and backcross DNAs digested with the restriction enzymes EcoRI, HindIII, or PstI, and Southern blotted to nylon membranes for hybridization. Of the newly reported Rcf probes, 7 (37%) were characterized as producing 'simple' polymorphic patterns, while 12 (63%) were characterized as producing 'complex' polymorphic patterns. Further characterization of the complex patterns subdivided this group into two general classes: polymorphisms that contained an additional allele, and multiple bands that contained an easily scored two banded polymorphism. Because the extra allele class was limited to the (P/C x C/C) backcross progeny, it is suggested that the inbred parental strain C108 harbors polymorphic loci that are inherited in a simple Mendelian fashion. A genetic analysis discussing plausible origins and maintenance of these polymorphisms is presented.

  2. Evidence of a Bottom-heavy Initial Mass Function in Massive Early-type Galaxies from Near-infrared Metal Lines

    Science.gov (United States)

    Lagattuta, David J.; Mould, Jeremy R.; Forbes, Duncan A.; Monson, Andrew J.; Pastorello, Nicola; Persson, S. Eric

    2017-09-01

    We present new evidence for a variable stellar initial mass function (IMF) in massive early-type galaxies, using high-resolution, near-infrared spectroscopy from the Folded-port InfraRed Echellette spectrograph (FIRE) on the Magellan Baade Telescope at Las Campanas Observatory. In this pilot study, we observe several gravity-sensitive metal lines between 1.1 and 1.3 μm in eight highly luminous (L˜ 10{L}* ) nearby galaxies. Thanks to the broad wavelength coverage of FIRE, we are also able to observe the Ca II triplet feature, which helps with our analysis. After measuring the equivalent widths (EWs) of these lines, we notice mild to moderate trends between EW and central velocity dispersion (σ), with some species (K I, Na I, Mn I) showing a positive EW-σ correlation and others (Mg I, Ca II, Fe I) a negative one. To minimize the effects of metallicity, we measure the ratio R = [EW(K I)/EW(Mg I)], finding a significant systematic increase in this ratio with respect to σ. We then probe for variations in the IMF by comparing the measured line ratios to the values expected in several IMF models. Overall, we find that low-mass galaxies (σ ˜ 100 km s-1) favor a Chabrier IMF, while high-mass galaxies (σ ˜ 350 km s-1) are better described with a steeper (dwarf-rich) IMF slope. While we note that our galaxy sample is small and may suffer from selection effects, these initial results are still promising. A larger sample of galaxies will therefore provide an even clearer picture of IMF trends in this regime. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

  3. Evidence for STAT4 as a common autoimmune gene: rs7574865 is associated with colonic Crohn's disease and early disease onset.

    Directory of Open Access Journals (Sweden)

    Jürgen Glas

    Full Text Available BACKGROUND: Recent studies demonstrated an association of STAT4 variants with systemic lupus erythematosus (SLE and rheumatoid arthritis (RA, indicating that multiple autoimmune diseases share common susceptibility genes. We therefore investigated the influence of STAT4 variants on the susceptibility and phenotype of inflammatory bowel diseases (IBD in a large patient and control cohort. METHODOLOGY/PRINCIPAL FINDINGS: Genomic DNA from 2704 individuals of Caucasian origin including 857 patients with Crohn's disease (CD, 464 patients with ulcerative colitis (UC, and 1383 healthy, unrelated controls was analyzed for seven SNPs in the STAT4 gene (rs11889341, rs7574865, rs7568275, rs8179673, rs10181656, rs7582694, rs10174238. In addition, a detailed genotype-phenotype analysis was performed. Our analysis revealed an association of the STAT4 SNP rs7574865 with overall decreased susceptibility to CD (p = 0.047, OR 0.86 [95% CI 0.74-0.99]. However, compared to CD patients carrying the wild type genotype, the STAT4 SNP rs7574865 was significantly associated with early CD onset (p = 0.021 and colonic CD (p = 0.008; OR = 4.60, 95% CI 1.63-12.96. For two other STAT4 variants, there was a trend towards protection against CD susceptibility (rs7568275, p = 0.058, OR 0.86 [95% CI 0.74-1.00]; rs10174238, p = 0.057, OR 0.86 [95% CI 0.75-1.00]. In contrast, we did not observe any association with UC susceptibility. Evidence for weak gene-gene interaction of STAT4 with the IL23R SNP rs11209026 was lost after Bonferroni correction. CONCLUSIONS/SIGNIFICANCE: Our results identified the STAT4 SNP rs7574865 as a disease-modifying gene variant in colonic CD. However, in contrast to SLE and RA, the effect of rs7574865 on CD susceptibility is only weak.

  4. Evidence for STAT4 as a common autoimmune gene: rs7574865 is associated with colonic Crohn's disease and early disease onset.

    Science.gov (United States)

    Glas, Jürgen; Seiderer, Julia; Nagy, Melinda; Fries, Christoph; Beigel, Florian; Weidinger, Maria; Pfennig, Simone; Klein, Wolfram; Epplen, Jörg T; Lohse, Peter; Folwaczny, Matthias; Göke, Burkhard; Ochsenkühn, Thomas; Diegelmann, Julia; Müller-Myhsok, Bertram; Roeske, Darina; Brand, Stephan

    2010-04-29

    Recent studies demonstrated an association of STAT4 variants with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), indicating that multiple autoimmune diseases share common susceptibility genes. We therefore investigated the influence of STAT4 variants on the susceptibility and phenotype of inflammatory bowel diseases (IBD) in a large patient and control cohort. Genomic DNA from 2704 individuals of Caucasian origin including 857 patients with Crohn's disease (CD), 464 patients with ulcerative colitis (UC), and 1383 healthy, unrelated controls was analyzed for seven SNPs in the STAT4 gene (rs11889341, rs7574865, rs7568275, rs8179673, rs10181656, rs7582694, rs10174238). In addition, a detailed genotype-phenotype analysis was performed. Our analysis revealed an association of the STAT4 SNP rs7574865 with overall decreased susceptibility to CD (p = 0.047, OR 0.86 [95% CI 0.74-0.99]). However, compared to CD patients carrying the wild type genotype, the STAT4 SNP rs7574865 was significantly associated with early CD onset (p = 0.021) and colonic CD (p = 0.008; OR = 4.60, 95% CI 1.63-12.96). For two other STAT4 variants, there was a trend towards protection against CD susceptibility (rs7568275, p = 0.058, OR 0.86 [95% CI 0.74-1.00]; rs10174238, p = 0.057, OR 0.86 [95% CI 0.75-1.00]). In contrast, we did not observe any association with UC susceptibility. Evidence for weak gene-gene interaction of STAT4 with the IL23R SNP rs11209026 was lost after Bonferroni correction. Our results identified the STAT4 SNP rs7574865 as a disease-modifying gene variant in colonic CD. However, in contrast to SLE and RA, the effect of rs7574865 on CD susceptibility is only weak.

  5. Snake pictures draw more early attention than spider pictures in non-phobic women: Evidence from event-related brain potentials

    OpenAIRE

    Strien, Jan; Eijlers, R.; Franken, Ingmar; Huijding, Jorg

    2014-01-01

    textabstractSnakes were probably the first predators of mammals and may have been important agents of evolutionary changes in the primate visual system allowing rapid visual detection of fearful stimuli (Isbell, 2006). By means of early and late attention-related brain potentials, we examined the hypothesis that more early visual attention is automatically allocated to snakes than to spiders. To measure the early posterior negativity (EPN), 24 healthy, non-phobic women watched the random rapi...

  6. Early Cannabis Use and Estimated Risk of Later Onset of Depression Spells : Epidemiologic Evidence From the Population-based World Health Organization World Mental Health Survey Initiative

    NARCIS (Netherlands)

    de Graaf, R.; Radovanovic, M.; van Laar, M.; Fairman, B.; Degenhardt, L.; Aguilar-Gaxiola, S.; Bruffaerts, R.; De Girolamo, G.; Fayyad, J.; Gureje, O.; Haro, J.M.; Huang, Y.Q.; Kostychenko, S.; Lepine, J.P.; Matschinger, H.; Mora, M.E.M.; Neumark, Y.; Ormel, J.; Posada-Villa, J.; Stein, D.J.; Tachimori, H.; Wells, J.E.; Anthony, J.C.

    2010-01-01

    Early-onset cannabis use is widespread in many countries and might cause later onset of depression. Sound epidemiologic data across countries are missing. The authors estimated the suspected causal association that links early-onset (age <17 years) cannabis use with later-onset (age >= 17 years)

  7. Petrogenesis of Early Cretaceous dioritic dikes in the Shanyang-Zhashui area, South Qinling, central China: Evidence for partial melting of thickened lower continental crust

    Science.gov (United States)

    Chen, Lei; Yan, Zhen; Wang, Zongqi; Wang, Kunming

    2018-06-01

    The dioritic dikes distributed in the Shanyang-Zhashui area of the South Qinling region play an important role in understanding the deep magmatic processes and tectonic evolution during the orogenic process. The zircon Usbnd Pb ages of the dioritic dikes indicate that they were emplaced at ∼144 Ma and therefore postdate the dikes that formed in the intracontinental orogenic background after the continental collision between the North China Block (NCB) and the South China Block (SCB). The dioritic dikes have SiO2 contents of 56.86-64.93 wt%; K2O contents of 1.65-3.21 wt%; low MgO (1.50-2.66 wt%), Y (14.4-25.5 ppm) and heavy rare earth element (HREE) contents; low Mg# values (39.9-49); high Sr contents (528-4833 ppm); and high Sr/Y ratios (32.8-189). They exhibit highly fractionated REE and flat HREE patterns, strong enrichment in large ion lithophile elements (LILEs; e.g., Rb, Ba, and U) and depletion in high field strength elements (HFSEs) (e.g., Nb), as well as positive Sr and negative Ti anomalies. Furthermore, these dioritic dikes exhibit (87Sr/86Sr)i ratios ranging from 0.7048 to 0.7083, εNd(t) values ranging from -3.3 to -1.4, and εHf(t) values ranging from -4.1 to 1.6. The geochemical patterns of the dioritic dikes indicate that they possess adakitic characteristics. Moreover, the low MgO contents, Mg# values, Ni contents, Th/Ce ratios, and Srsbnd Ndsbnd Hf isotopic features all indicate that these dioritic dikes were generated by the partial melting of thickened mafic lower crust. The high La/Yb and Sr/Y ratios, low Y and Yb contents, absence of significant Eu anomalies, flat HREE patterns, and low Nb/Ta ratios of these rocks suggest that the adakitic melts were derived from the melting of garnet-bearing amphibolite. The geochronologic, elemental and isotopic evidence suggests that the dioritic dikes may have formed in a locally extensional environment within an overall N-S compressional setting or during the transition from compressional to extensional

  8. Evidence that children born at early term (37-38 6/7 weeks) are at increased risk for diabetes and obesity-related disorders.

    Science.gov (United States)

    Paz Levy, Dorit; Sheiner, Eyal; Wainstock, Tamar; Sergienko, Ruslan; Landau, Daniella; Walfisch, Asnat

    2017-11-01

    Prematurity is known to be associated with high rates of endocrine and metabolic complications in the offspring. Offspring born early term (37-38 6/7 weeks' gestation) were also shown to exhibit long-term morbidity resembling that of late preterm, in several health categories. We aimed to determine whether early term delivery impacts on the long-term endocrine and metabolic health of the offspring. A population-based cohort analysis was performed, including all term singleton deliveries occurring from 1991 through 2013 at a single regional tertiary medical center. Congenital malformations and multiple pregnancies were excluded. Gestational age upon delivery was subdivided into early term deliveries and deliveries occurring at full term and later (≥39 weeks' gestation, comparison group). Endocrine and metabolic morbidity (including diabetes, obesity, hypoglycemia, hyperlipidemia, and hypothyroidism) of the offspring, up to the age of 18 years, was evaluated according to hospitalization files. Kaplan-Meier survival curves were used to compare cumulative morbidity incidence. A Weibull parametric survival model was used to control for time to event, siblings, and other confounders. During the study period 225,260 term deliveries met the inclusion criteria. Of them, 24% (n = 54,073) occurred at early term. Endocrine and metabolic morbidity was significantly more common in the early term group (0.51% vs 0.41%, P = .003). Specifically, overweight and obesity were more common among the early term group (P = .002). Differences were more prominent among children >5 years, who exhibited higher rates of type 1 diabetes mellitus, as well as obesity, when born at early term (P diabetes, hypertension, labor induction, and Apgar score, early term delivery exhibited an independent association with long-term childhood endocrine and metabolic morbidity of the offspring (adjusted hazard ratio, 1.17; 95% confidence interval, 1.01-1.34) and more so for age >5 years (adjusted hazard

  9. Early Alzheimer's and Parkinson's Disease Pathology in Urban Children: Friend versus Foe Responses—It Is Time to Face the Evidence

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Franco-Lira, Maricela; Mora-Tiscareño, Antonieta; Medina-Cortina, Humberto; Torres-Jardón, Ricardo; Kavanaugh, Michael

    2013-01-01

    Chronic exposure to particulate matter air pollution is known to cause inflammation leading to respiratory- and cardiovascular-related sickness and death. Mexico City Metropolitan Area children exhibit an early brain imbalance in genes involved in oxidative stress, inflammation, and innate and adaptive immune responses. Early dysregulated neuroinflammation, brain microvascular damage, production of potent vasoconstrictors, and perturbations in the integrity of the neurovascular unit likely contribute to progressive neurodegenerative processes. The accumulation of misfolded proteins coincides with the anatomical distribution observed in the early stages of both Alzheimer's and Parkinson's diseases. We contend misfolding of hyperphosphorylated tau (HPπ), alpha-synuclein, and beta-amyloid could represent a compensatory early protective response to the sustained systemic and brain inflammation. However, we favor the view that the chronic systemic and brain dysregulated inflammation and the diffuse vascular damage contribute to the establishment of neurodegenerative processes with childhood clinical manifestations. Friend turns Foe early; therefore, implementation of neuroprotective measures to ameliorate or stop the inflammatory and neurodegenerative processes is warranted in exposed children. Epidemiological, cognitive, structural, and functional neuroimaging and mechanistic studies into the association between air pollution exposures and the development of neuroinflammation and neurodegeneration in children are of pressing importance for public health. PMID:23509683

  10. Early Alzheimer's and Parkinson's disease pathology in urban children: Friend versus Foe responses--it is time to face the evidence.

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Franco-Lira, Maricela; Mora-Tiscareño, Antonieta; Medina-Cortina, Humberto; Torres-Jardón, Ricardo; Kavanaugh, Michael

    2013-01-01

    Chronic exposure to particulate matter air pollution is known to cause inflammation leading to respiratory- and cardiovascular-related sickness and death. Mexico City Metropolitan Area children exhibit an early brain imbalance in genes involved in oxidative stress, inflammation, and innate and adaptive immune responses. Early dysregulated neuroinflammation, brain microvascular damage, production of potent vasoconstrictors, and perturbations in the integrity of the neurovascular unit likely contribute to progressive neurodegenerative processes. The accumulation of misfolded proteins coincides with the anatomical distribution observed in the early stages of both Alzheimer's and Parkinson's diseases. We contend misfolding of hyperphosphorylated tau (HPπ), alpha-synuclein, and beta-amyloid could represent a compensatory early protective response to the sustained systemic and brain inflammation. However, we favor the view that the chronic systemic and brain dysregulated inflammation and the diffuse vascular damage contribute to the establishment of neurodegenerative processes with childhood clinical manifestations. Friend turns Foe early; therefore, implementation of neuroprotective measures to ameliorate or stop the inflammatory and neurodegenerative processes is warranted in exposed children. Epidemiological, cognitive, structural, and functional neuroimaging and mechanistic studies into the association between air pollution exposures and the development of neuroinflammation and neurodegeneration in children are of pressing importance for public health.

  11. Snake pictures draw more early attention than spider pictures in non-phobic women: evidence from event-related brain potentials.

    Science.gov (United States)

    Van Strien, J W; Eijlers, R; Franken, I H A; Huijding, J

    2014-02-01

    Snakes were probably the first predators of mammals and may have been important agents of evolutionary changes in the primate visual system allowing rapid visual detection of fearful stimuli (Isbell, 2006). By means of early and late attention-related brain potentials, we examined the hypothesis that more early visual attention is automatically allocated to snakes than to spiders. To measure the early posterior negativity (EPN), 24 healthy, non-phobic women watched the random rapid serial presentation of 600 snake pictures, 600 spider pictures, and 600 bird pictures (three pictures per second). To measure the late positive potential (LPP), they also watched similar pictures (30 pictures per stimulus category) in a non-speeded presentation. The EPN amplitude was largest for snake pictures, intermediate for spider pictures and smallest for bird pictures. The LPP was significantly larger for both snake and spider pictures when compared to bird pictures. Interestingly, spider fear (as measured by a questionnaire) was associated with EPN amplitude for spider pictures, whereas snake fear was not associated with EPN amplitude for snake pictures. The results suggest that ancestral priorities modulate the early capture of visual attention and that early attention to snakes is more innate and independent of reported fear. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Early Alzheimer’s and Parkinson’s Disease Pathology in Urban Children: Friend versus Foe Responses—It Is Time to Face the Evidence

    Directory of Open Access Journals (Sweden)

    Lilian Calderón-Garcidueñas

    2013-01-01

    Full Text Available Chronic exposure to particulate matter air pollution is known to cause inflammation leading to respiratory- and cardiovascular-related sickness and death. Mexico City Metropolitan Area children exhibit an early brain imbalance in genes involved in oxidative stress, inflammation, and innate and adaptive immune responses. Early dysregulated neuroinflammation, brain microvascular damage, production of potent vasoconstrictors, and perturbations in the integrity of the neurovascular unit likely contribute to progressive neurodegenerative processes. The accumulation of misfolded proteins coincides with the anatomical distribution observed in the early stages of both Alzheimer’s and Parkinson's diseases. We contend misfolding of hyperphosphorylated tau (HPπ, alpha-synuclein, and beta-amyloid could represent a compensatory early protective response to the sustained systemic and brain inflammation. However, we favor the view that the chronic systemic and brain dysregulated inflammation and the diffuse vascular damage contribute to the establishment of neurodegenerative processes with childhood clinical manifestations. Friend turns Foe early; therefore, implementation of neuroprotective measures to ameliorate or stop the inflammatory and neurodegenerative processes is warranted in exposed children. Epidemiological, cognitive, structural, and functional neuroimaging and mechanistic studies into the association between air pollution exposures and the development of neuroinflammation and neurodegeneration in children are of pressing importance for public health.

  13. An early cretaceous phase of accelerated erosion on the south-western margin of Africa: evidence from apatite fission track analysis and the offshore sedimentary record

    International Nuclear Information System (INIS)

    Brown, R.W.; Gleadow, A.J.W.; Rust, D.J.; Summerfield, M.A.; De Wit, M.C.J.

    1990-01-01

    Apatite fission track ages and confined track length distributions have been determined for rock samples from the south-western continental margin of Africa. The apatite ages fall into two groups, one having early Cretaceous ages and mean confined track lengths of ∼ 14 μm with very few short tracks, and the other having older ages with confined track length distributions containing a significant proportion of strongly annealed tracks (<10 μm). In any particular area the older apatite ages only occur above a critical threshold elevation, forming a regional pattern in the data and indicating cooling of the upper few kilometres of the crust during the early cretaceous. This episode of cooling is shown to have been the consequence of an accelerated phase of erosion associated with the early stages of rifting and break-up of Gondwana, and correlates with sedimentation patterns derived from borehole data for the adjacent offshore basin. (author)

  14. An early cretaceous phase of accelerated erosion on the south-western margin of Africa: evidence from apatite fission track analysis and the offshore sedimentary record

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.W.; Gleadow, A.J.W. (La Trobe Univ., Bundoora (Australia)); Rust, D.J.; Summerfield, M.A. (Edinburgh Univ. (UK)); De Wit, M.C.J. (De Beers Consolidated Mines Ltd., Kimberley (South Africa))

    1990-01-01

    Apatite fission track ages and confined track length distributions have been determined for rock samples from the south-western continental margin of Africa. The apatite ages fall into two groups, one having early Cretaceous ages and mean confined track lengths of {approx} 14 {mu}m with very few short tracks, and the other having older ages with confined track length distributions containing a significant proportion of strongly annealed tracks (<10 {mu}m). In any particular area the older apatite ages only occur above a critical threshold elevation, forming a regional pattern in the data and indicating cooling of the upper few kilometres of the crust during the early cretaceous. This episode of cooling is shown to have been the consequence of an accelerated phase of erosion associated with the early stages of rifting and break-up of Gondwana, and correlates with sedimentation patterns derived from borehole data for the adjacent offshore basin. (author).

  15. No evidence for activated autophagy in left ventricular myocardium at early reperfusion with protection by remote ischemic preconditioning in patients undergoing coronary artery bypass grafting.

    Directory of Open Access Journals (Sweden)

    Nilgün Gedik

    Full Text Available Remote ischemic preconditioning (RIPC by repeated brief limb ischemia/reperfusion reduces myocardial injury in patients undergoing coronary artery bypass grafting (CABG. Activation of signal transducer and activator of transcription 5 (STAT5 in left ventricular (LV myocardium at early reperfusion is associated with such protection. Autophagy, i.e., removal of dysfunctional cellular components through lysosomes, has been proposed as one mechanism of cardioprotection. Therefore, we analyzed whether or not the protection by RIPC is associated with activated autophagy.CABG patients were randomized to undergo RIPC (3×5 min blood pressure cuff inflation/5 min deflation or placebo (cuff deflated before skin incision (n = 10/10. Transmural myocardial biopsies were taken from the LV before cardioplegia (baseline and at early (5-10 min reperfusion. RIPC-induced protection was reflected by decreased serum troponin I concentration area under the curve (194±17 versus 709±129 ng/ml × 72 h, p = 0.002. Western blotting for beclin-1-phosphorylation and protein expression of autophagy-related gene 5-12 (ATG5-12 complex, light chain 3 (LC3, parkin, and p62 was performed. STAT3-, STAT5- and extracellular signal-regulated protein kinase 1/2 (ERK1/2-phosphorylation was used as positive control to confirm signal activation by ischemia/reperfusion.Signals of all analyzed autophagy proteins did not differ between baseline and early reperfusion and not between RIPC and placebo. STAT5-phosphorylation was greater at early reperfusion only with RIPC (2.2-fold, p = 0.02. STAT3- and ERK1/2-phosphorylation were greater at early reperfusion with placebo and RIPC (≥2.7-fold versus baseline, p≤0.05.Protection through RIPC in patients undergoing CABG surgery does not appear to be associated with enhanced autophagy in LV myocardium at early reperfusion.

  16. Thymic Output and CD4 T-Cell Reconstitution in HIV-Infected Children on Early and Interrupted Antiretroviral Treatment: Evidence from the Children with HIV Early Antiretroviral Therapy Trial

    Directory of Open Access Journals (Sweden)

    Joanna Lewis

    2017-09-01

    Full Text Available ObjectivesEarly treatment of HIV-infected children and adults is important for optimal immune reconstitution. Infants’ immune systems are more plastic and dynamic than older children’s or adults’, and deserve particular attention. This study aimed to understand the response of the HIV-infected infant immune system to early antiretroviral therapy (ART and planned ART interruption and restart.MethodsData from HIV-infected children enrolled the CHER trial, starting ART aged between 6 and 12 weeks, were used to explore the effect of ART on immune reconstitution. We used linear and non-linear regression and mixed-effects models to describe children’s CD4 trajectories and to identify predictors of CD4 count during early and interrupted ART.ResultsEarly treatment arrested the decline in CD4 count but did not fully restore it to the levels observed in HIV-uninfected children. Treatment interruption at 40 or 96 weeks resulted in a rapid decline in CD4 T-cells, which on retreatment returned to levels observed before interruption. Naïve CD4 T-cell count was an important determinant of overall CD4 levels. A strong correlation was observed between thymic output and the stable CD4 count both before and after treatment interruption.ConclusionEarly identification and treatment of HIV-infected infants is important to stabilize CD4 counts at the highest levels possible. Once stabilized, children’s CD4 counts appear resilient, with good potential for recovery following treatment interruption. The naïve T-cell pool and thymic production of naive cells are key determinants of children’s CD4 levels.

  17. On the possibility of life on early Mars

    Science.gov (United States)

    Oberbeck, V. R.; Fogleman, G.

    1990-01-01

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

  18. No Own-Age Bias in 3-Year-Old Children: More Evidence for the Role of Early Experience in Building Face-Processing Biases

    Science.gov (United States)

    Cassia, Viola Macchi; Pisacane, Antonella; Gava, Lucia

    2012-01-01

    This study aimed to investigate the presence of an own-age bias in young children who accumulated different amounts of early experience with child faces. Discrimination abilities for upright and inverted adult and child faces were tested using a delayed two-alternative, forced-choice matching-to-sample task in two groups of 3-year-old children,…

  19. Preliminary analysis of the very early diagnosis of systemic sclerosis (VEDOSS) EUSTAR multicentre study: evidence for puffy fingers as a pivotal sign for suspicion of systemic sclerosis.

    NARCIS (Netherlands)

    Minier, T.; Guiducci, S.; Bellando-Randone, S.; Bruni, C.; Lepri, G.; Czirjak, L.; Distler, O.; Walker, U.A.; Fransen, J.; Allanore, Y.; Denton, C.; Cutolo, M.; Tyndall, A.; Muller-Ladner, U.; Matucci-Cerinic, M.

    2014-01-01

    OBJECTIVES: The EULAR (European League Against Rheumatism) Scleroderma Trials and Research Group (EUSTAR) has identified preliminary criteria for very early diagnosis of systemic sclerosis (SSc). Our aim was to assess the prevalence of each proposed diagnostic item in a large observational patient

  20. Snake pictures draw more early attention than spider pictures in non-phobic women : Evidence from event-related brain potentials

    NARCIS (Netherlands)

    Van Strien, J. W.; Eijlers, R.; Franken, I. H A; Huijding, J.|info:eu-repo/dai/nl/292646976

    Snakes were probably the first predators of mammals and may have been important agents of evolutionary changes in the primate visual system allowing rapid visual detection of fearful stimuli (Isbell, 2006). By means of early and late attention-related brain potentials, we examined the hypothesis

  1. Snake pictures draw more early attention than spider pictures in non-phobic women: Evidence from event-related brain potentials

    NARCIS (Netherlands)

    J.W. van Strien (Jan); R. Eijlers (R.); I.H.A. Franken (Ingmar); J. Huijding (Jorg)

    2014-01-01

    textabstractSnakes were probably the first predators of mammals and may have been important agents of evolutionary changes in the primate visual system allowing rapid visual detection of fearful stimuli (Isbell, 2006). By means of early and late attention-related brain potentials, we examined the

  2. Connecting the Dots: Raising a Reader Builds Evidence Base for Its Parent Engagement and Early Literacy Program. Research Report. Publication #2014-60

    Science.gov (United States)

    Walker, Karen; Gooze, Rachel A.; Torres, Alicia

    2014-01-01

    Early literacy skills are the foundation for school success. This is particularly important for groups of children at heightened risk of poor educational outcomes, such as English language learners and children from low-income families. Informed by a growing body of research and evaluation studies that point to the importance of home literacy…

  3. Early Oral Language and Later Reading Development in Spanish-Speaking English Language Learners: Evidence from a Nine-Year Longitudinal Study

    Science.gov (United States)

    Kieffer, Michael J.

    2012-01-01

    Using nationally-representative, longitudinal data on a cohort of Spanish-speaking English language learners in the U.S., this study investigated the extent to which early oral language proficiency in Spanish and English predicts later levels and rates of growth in English reading. Latent growth models indicated that both Spanish and English…

  4. About evidence based and beyond: a discourse-analytic study of stakeholders' talk on involvement in the early development of personalized nutrition

    NARCIS (Netherlands)

    Bouwman, L.I.; Molder, te H.F.M.

    2009-01-01

    This paper draws on discourse analysis to examine how Dutch stakeholders in health education, health care, health insurance, social science, the food industry and the media make sense of innovations in the field of `personalized nutrition¿ and their own role and significance in an early stage of

  5. Informing Educational Decisions in the Early Years: Can Evidence for Improving Pedagogy for Children with Autistic Spectrum Disorder Be Found from Neuroscience?

    Science.gov (United States)

    Peters, Brenda; Forlin, Chris

    2011-01-01

    It is possible that many benefits may be found for all concerned in education and child development in understanding how knowledge of the brain and its development can inform early years practice. This article, written by Brenda Peters and Chris Forlin, both from the Hong Kong Institute of Education, reviews literature based on neuroscience to…

  6. Family Support or School Readiness? Contrasting Models of Public Spending on Children's Early Care and Learning. Evidence Speaks Reports, Vol 1, #16

    Science.gov (United States)

    Whitehurst, Grover J.

    2016-01-01

    In the United States, public policy and expenditure intended to improve the prospects of children from low-income families have focused on better preparing children for school through Head Start and universal pre-K. This school readiness approach differs from the dominant model of public support for early care and learning in Northern Europe,…

  7. Shame and Guilt in Preschool Depression: Evidence for Elevations in Self-Conscious Emotions in Depression as Early as Age 3

    Science.gov (United States)

    Luby, Joan; Belden, Andy; Sullivan, Jill; Hayen, Robin; McCadney, Amber; Spitznagel, Ed

    2009-01-01

    Background: Empirical findings from two divergent bodies of literature illustrate that depression can arise in the preschool period and that the complex self-conscious emotions of guilt and shame may develop normatively as early as age 3. Despite these related findings, few studies have examined whether the emotions of shame and guilt are salient…

  8. Evidence for an agitated-aggressive syndrome in early-onset psychosis correlated with antisocial personality disorder, forensic history, and substance use disorder.

    Science.gov (United States)

    Huber, Christian G; Hochstrasser, Lisa; Meister, Klara; Schimmelmann, Benno G; Lambert, Martin

    2016-08-01

    Agitation, aggression, and violence are increased in psychotic disorders. Additionally, an earlier age at onset may be associated with aggressive behavior. However, the relationship of age at onset, an agitated-aggressive syndrome as measured with the Positive And Negative Syndrome Scale for Schizophrenia - Excited Component (PANSS-EC), and its potential correlates in first-episode psychosis (FEP) has not been studied. This study assessed the association between age at onset, an agitated-aggressive syndrome, and its potential correlates in a prospective sample of 52 FEP patients with early-onset and adult-onset followed up for 12months. Twenty-six patients conformed to the criteria of early-onset psychosis. Early age at onset was associated with antisocial personality disorder (p=0.004; φc=0.39), a history of legal involvement (p=0.005; φc=0.39), and higher rates of lifetime substance use disorder (SUD; p=0.002; φc=0.42). Early-onset patients had significantly higher PANSS-EC scores over the course of observation (F(1,44.4)=5.39; p=0.025; d=0.656), but no significant group differences emerged for the remaining PANSS subscores. PANSS-EC scores were correlated positively with antisocial personality disorder and forensic history at 6weeks, 3months, 6months, and 12months, and with lifetime substance use disorder at 3months and 6months. Patients with early onset psychosis may have increased levels of agitation/aggressiveness, and, more likely, antisocial personality disorder, forensic history, and lifetime substance use disorder. These variables were linked to suicidality, aggressiveness, and involuntary treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Further Evidence of a Cohort Effect in Bipolar Disorder : More Early Onsets and Family History of Psychiatric Illness in More Recent Epochs

    NARCIS (Netherlands)

    Post, Robert M.; Kupka, Ralph; Keck, Paul E.; McElroy, Susan L.; Altshuler, Lori L.; Frye, Mark A.; Rowe, Michael; Grunze, Heinz; Suppes, Trisha; Leverich, Gabriele S.; Nolen, Willem A.

    Objective: Given that a cohort effect is rarely mentioned as one of the possible contributors to the increased incidence of childhood-onset bipolar disorder in the United States, we reexamined evidence for the phenomenon within our outpatient Bipolar Collaborative Network. Methods: 968 outpatients

  10. Epidemiologic evidence of health effects from long-distance transit of chemical weapons fallout from bombing early in the 1991 Persian Gulf War.

    Science.gov (United States)

    Haley, Robert W; Tuite, James J

    2013-01-01

    Military intelligence data published in a companion paper explain how chemical fallout from US and Coalition bombing of Iraqi chemical weapons facilities early in the air campaign transited long distance, triggering nerve agent alarms and exposing US troops. We report the findings of a population-based survey designed to test competing hypotheses on the impact on chronic Gulf War illness of nerve agent from early-war bombing versus post-war demolition. The US Military Health Survey performed computer-assisted telephone interviews of a stratified random sample of Gulf War-era veterans (n = 8,020). Early-war exposure was measured by having heard nerve agent alarms and post-war exposure, by the computer-generated plume from the Khamisiyah demolition. Gulf War illness was measured by two widely published case definitions. The OR (95% CI) for the association of alarms with the Factor case definition was 4.13 (95% CI 2.51-6.80) compared with 1.21 (95% CI 0.86-1.69) for the Khamisiyah plume. There was a dose-related trend for the number of alarms (p(trend) war demolition. Copyright © 2012 S. Karger AG, Basel.

  11. Early Cretaceous MORB-type basalt and A-type rhyolite in northern Tibet: Evidence for ridge subduction in the Bangong-Nujiang Tethyan Ocean

    Science.gov (United States)

    Fan, Jian-Jun; Li, Cai; Sun, Zhen-Ming; Xu, Wei; Wang, Ming; Xie, Chao-Ming

    2018-04-01

    New zircon U-Pb ages, major- and trace-element data, and Hf isotopic compositions are presented for bimodal volcanic rocks of the Zhaga Formation (ZF) in the western-middle segment of the Bangong-Nujiang suture zone (BNSZ), northern Tibet. The genesis of these rocks is described, and implications for late-stage evolution of the Bangong-Nujiang Tethyan Ocean (BNTO) are considered. Detailed studies show that the ZF bimodal rocks, which occur as layers within a typical bathyal to abyssal flysch deposit, comprise MORB-type basalt that formed at a mid-ocean ridge, and low-K calc-alkaline A-type rhyolite derived from juvenile crust. The combination of MORB-type basalt, calc-alkaline A-type rhyolite, and bathyal to abyssal flysch deposits in the ZF leads us to propose that they formed as a result of ridge subduction. The A-type ZF rhyolites yield LA-ICP-MS zircon U-Pb ages of 118-112 Ma, indicating formation during the Early Cretaceous. Data from the present study, combined with regional geological data, indicate that the BNTO underwent conversion from ocean opening to ocean closure during the Late Jurassic-Early Cretaceous. The eastern segment of the BNTO closed during this period, while the western and western-middle segments were still at least partially open and active during the Early Cretaceous, accompanied by ridge subduction within the Bangong-Nujiang Tethyan Ocean.

  12. Association of nursery and early school attendance with later health behaviours, biomedical risk factors, and mortality: evidence from four decades of follow-up of participants in the 1958 birth cohort study.

    Science.gov (United States)

    Batty, G David; Ploubidis, George B; Goodman, Alissa; Bann, David

    2018-03-14

    Although early life education for improved long-term health and the amelioration of socioeconomically generated inequalities in chronic disease is advocated in influential policy statements, the evidence base is very modest. To address this dearth of evidence using data from a representative UK national birth cohort study. The analytical sample comprised men and women in the 1958 birth cohort study with prospectively gathered data on attendance at nursery or primary school before the age of 5 years who had gone on to participate in social survey at 42 years (n=11 374), or a biomedical survey at 44/5 years of age (n=9210), or had data on vital status from 18 to 55 years (n=17 657). Relative to study members who had not attended nursery, in those who had, there was in fact a higher prevalence of smoking and high alcohol intake in middle age. Conversely, nursery attenders had more favourable levels of lung function and systolic blood pressure in middle age. This apparent association between nursery attendance and lower systolic blood pressure was confined to study members from more deprived social backgrounds of origin (P value for interaction 0.030). There was no apparent link between early school attendance and any behavioural or biological risk factor. Neither nursery nor early school attendance was clearly related to mortality risk. We found no clear evidence for an association of either attendance at nursery or primary school before the age of 5 years and health outcomes around four decades later. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  13. Late Carboniferous to early Permian sedimentary–tectonic evolution of the north of Alxa, Inner Mongolia, China: Evidence from the Amushan Formation

    Directory of Open Access Journals (Sweden)

    Haiquan Yin

    2016-09-01

    Full Text Available The late Paleozoic evolution of the Wulijishanhen (WSH-Shangdan (SD area near to the Chaganchulu Ophiolite belt is reinterpreted. Analysis of the upper Carboniferous to lower Permian sedimentary sequence, biological associations, detrital materials, sandstone geochemistry and volcanic rocks indicates that the SD area was an epicontinental sea and rift during the late Paleozoic rather than a large-scale ocean undergoing spreading and closure. This study reveals that the actual evolution of the study area is from the late Carboniferous to the early Permian. The fusulinids Triticites sp. and Pseudoschwagerina sp. in the limestones demonstrate that the Amushan Formation develops during the late Carboniferous to the early Permian. The limestones at the base of the SD section indicate that it is a stable carbonate platform environment, the volcanic rocks in the middle of the sequence support a rift tectonic background, and the overlying conglomerates and sandstones are characteristic of an epicontinental sea or marine molasse setting. The rift volcanism made the differences in the fossil content of the SD and WSH sections and led to two sections expose different levels within the Amushan Formation and different process of tectonic evolution. Moreover, the geochemical characteristics and detrital materials of the sandstones show that the provenance and formation of the sandstones were related to the setting of active continental margin. The quartz-feldspar-lithic fragments distribution diagram indicates that the material source for the sandstones was a recycled orogenic belt. Thus, the source area of the sandstones may have been an active continental margin before the late Carboniferous–early Permian. The characteristics of the regional tectonic evolution of the area indicate that the region may form a small part of the Gobi–Tianshan rift of southern Mongolia.

  14. The X-Ray Luminosity Functions of Field Low-Mass X-Ray Binaries in Early-Type Galaxies: Evidence for a Stellar Age Dependence

    Science.gov (United States)

    Lehmer, B. D.; Berkeley, M.; Zezas, A.; Alexander, D. M.; Basu-Zych, A.; Bauer, F. E.; Brandt, W. N.; Fragos, T.; Hornschemeier, A. E.; Kalogera, V.; hide

    2014-01-01

    We present direct constraints on how the formation of low-mass X-ray binary (LMXB) populations in galactic fields depends on stellar age. In this pilot study, we utilize Chandra and Hubble Space Telescope (HST) data to detect and characterize the X-ray point source populations of three nearby early-type galaxies: NGC 3115, 3379, and 3384. The luminosity-weighted stellar ages of our sample span approximately equal to 3-10 Gyr. X-ray binary population synthesis models predict that the field LMXBs associated with younger stellar populations should be more numerous and luminous per unit stellar mass than older populations due to the evolution of LMXB donor star masses. Crucially, the combination of deep Chandra and HST observations allows us to test directly this prediction by identifying and removing counterparts to X-ray point sources that are unrelated to the field LMXB populations, including LMXBs that are formed dynamically in globular clusters, Galactic stars, and background AGN/galaxies. We find that the "young" early-type galaxy NGC 3384 (approximately equals 2-5 Gyr) has an excess of luminous field LMXBs (L(sub x) approximately greater than (5-10) × 10(exp 37) erg s(exp -1)) per unit K-band luminosity (L(sub K); a proxy for stellar mass) than the "old" early-type galaxies NGC 3115 and 3379 (approximately equals 8-10 Gyr), which results in a factor of 2-3 excess of L(sub X)/L(sub K) for NGC 3384. This result is consistent with the X-ray binary population synthesis model predictions; however, our small galaxy sample size does not allow us to draw definitive conclusions on the evolution field LMXBs in general. We discuss how future surveys of larger galaxy samples that combine deep Chandra and HST data could provide a powerful new benchmark for calibrating X-ray binary population synthesis models.

  15. From Disks to Planets: The Making of Planets and Their Early Atmospheres. An Introduction

    Science.gov (United States)

    Lammer, Helmut; Blanc, Michel

    2018-03-01

    This paper is an introduction to volume 56 of the Space Science Series of ISSI, "From disks to planets—the making of planets and their proto-atmospheres", a key subject in our quest for the origins and evolutionary paths of planets, and for the causes of their diversity. Indeed, as exoplanet discoveries progressively accumulated and their characterization made spectacular progress, it became evident that the diversity of observed exoplanets can in no way be reduced to the two classes of planets that we are used to identify in the solar system, namely terrestrial planets and gas or ice giants: the exoplanet reality is just much broader. This fact is no doubt the result of the exceptional diversity of the evolutionary paths linking planetary systems as a whole as well as individual exoplanets and their proto-atmospheres to their parent circumstellar disks: this diversity and its causes are exactly what this paper explores. For each of the main phases of the formation and evolution of planetary systems and of individual planets, we summarize what we believe we understand and what are the important open questions needing further in-depth examination, and offer some suggestions on ways towards solutions. We start with the formation mechanisms of circumstellar disks, with their gas and disk components in which chemical composition plays a very important role in planet formation. We summarize how dust accretion within the disk generates planet cores, while gas accretion on these cores can lead to the diversity of their fluid envelopes. The temporal evolution of the parent disk itself, and its final dissipation, put strong constraints on how and how far planetary formation can proceed. The radiation output of the central star also plays an important role in this whole story. This early phase of planet evolution, from disk formation to dissipation, is characterized by a co-evolution of the disk and its daughter planets. During this co-evolution, planets and their

  16. Pediatric surgeons and anesthesiologists expand the dialogue on the neurotoxicity question, rationale for early and delayed surgeries, and practice changes while awaiting definitive evidence.

    Science.gov (United States)

    Byrne, Mary W; Casale, Pasquale; Garzon, Maria; Hyman, Joshua E; Lin, Albert Y; Lynch, Lisa R; Schleien, Charles L; Stylianos, Steven

    2014-10-01

    The Pediatric Anesthesia NeuroDevelopment Assessment team at Columbia University Medical Center Department of Anesthesiology convened its fourth biennial Symposium to address unresolved issues concerning potential neurotoxic effects of anesthetic agents and sedatives on young children and to assess study findings to date. Dialogue initiated at the third Symposium was continued between anesthesiologists, researchers, and a panel of expert pediatric surgeons representing general surgery and dermatology, orthopedic, and urology specialties. The panel explored the need to balance benefits of early surgery using improved technologies against potential anesthetic risks, practice changes while awaiting definitive answers, and importance of continued interprofessional dialogue.

  17. Achievement gaps and correlates of early mathematics achievement: Evidence from the ECLS K—first grade sample. Vol. 13 No. 46

    Directory of Open Access Journals (Sweden)

    Madhabi Chatterji

    2005-11-01

    Full Text Available In light of the NCLB Act of 2001, this study estimated mathematics achievement gaps in different subgroups of kindergartners and first graders, and identified child- and school-level correlates and moderators of early mathematics achievement. A subset of 2300 students nested in 182 schools from the Early Childhood Longitudinal Study K-First Grade data set was analyzed with hierarchical linear models. Relative to school mean estimates at the end of kindergarten, significant mathematics achievement gaps were found in Hispanics, African Americans and high poverty students. At the end of Grade 1, mathematics gaps were significant in African American, high poverty, and female subgroups, but not in Hispanics. School-level correlates of Grade 1 Mathematics achievement were class size (with a small negative main effect, at-home reading time by parents (with a large positive main effect and school size (with a small positive main effect. Cross-level interactions in Grade 1 indicated that schools with larger class and school sizes had a negative effect on African American children's math scores; schools giving more instructional time to reading and math had a positive effect on high poverty students' scores, and schools with higher elementary teacher certification rates had a positive effect on boys' mathematics achievement.

  18. First-hand sensory experience plays a limited role in children's early understanding of seeing and hearing as sources of knowledge: evidence from typically hearing and deaf children.

    Science.gov (United States)

    Schmidt, Ellyn; Pyers, Jennie

    2014-11-01

    One early-developing component of theory of mind is an understanding of the link between sensory perception and knowledge formation. We know little about the extent to which children's first-hand sensory experiences drive the development of this understanding, as most tasks capturing this early understanding target vision, with less attention paid to the other senses. In this study, 64 typically hearing children (Mage  = 4.0 years) and 21 orally educated deaf children (Mage  = 5.44 years) were asked to identify which of two informants knew the identity of a toy animal when each had differing perceptual access to the animal. In the 'seeing' condition, one informant saw the animal and the other did not; in the 'hearing' condition, one informant heard the animal and the other did not. For both hearing and deaf children, there was no difference between performance on hearing and seeing trials, but deaf children were delayed in both conditions. Further, within both the hearing and deaf groups, older children outperformed younger children on these tasks, indicating that there is a developmental progression. Taken together, the pattern of results suggests that experiences other than first-hand sensory experiences drive children's developing understanding that sensory perception is associated with knowledge. © 2014 The British Psychological Society.

  19. A long-lived Late Cretaceous-early Eocene extensional province in Anatolia? Structural evidence from the Ivriz Detachment, southern central Turkey

    Science.gov (United States)

    Gürer, Derya; Plunder, Alexis; Kirst, Frederik; Corfu, Fernando; Schmid, Stefan M.; van Hinsbergen, Douwe J. J.

    2018-01-01

    Central Anatolia exposes previously buried and metamorphosed, continent-derived rocks - the Kırşehir and Afyon zones - now covering an area of ∼300 × 400 km. So far, the exhumation history of these rocks has been poorly constrained. We show for the first time that the major, >120 km long, top-NE 'Ivriz' Detachment controlled the exhumation of the HP/LT metamorphic Afyon Zone in southern Central Anatolia. We date its activity at between the latest Cretaceous and early Eocene times. Combined with previously documented isolated extensional detachments found in the Kırşehir Block, our results suggest that a major province governed by extensional exhumation was active throughout Central Anatolia between ∼80 and ∼48 Ma. Although similar in dimension to the Aegean extensional province to the east, the Central Anatolian extensional province is considerably older and was controlled by a different extension direction. From this, we infer that the African slab(s) that subducted below Anatolia must have rolled back relative to the Aegean slab since at least the latest Cretaceous, suggesting that these regions were underlain by a segmented slab. Whether or not these early segments already corresponded to the modern Aegean, Antalya, and Cyprus slab segments remains open for debate, but slab segmentation must have occurred much earlier than previously thought.

  20. Detection of Enhanced Central Mass-to-light Ratios in Low-mass Early-type Galaxies: Evidence for Black Holes?

    Science.gov (United States)

    Pechetti, Renuka; Seth, Anil; Cappellari, Michele; McDermid, Richard; den Brok, Mark; Mieske, Steffen; Strader, Jay

    2017-11-01

    We present dynamical measurements of the central mass-to-light ratio (M/L) of a sample of 27 low-mass early-type {{ATLAS}}3{{D}} galaxies. We consider all {{ATLAS}}3{{D}} galaxies with 9.7 text{}}M/L{{s}} are higher than dynamical {\\text{}}M/L{{s}} derived at larger radii and stellar population estimates of the galaxy centers in ˜80% of galaxies, with a median enhancement of ˜14% and a statistical significance of 3.3σ. We show that the enhancement in the central M/L is best described either by the presence of black holes in these galaxies or by radial initial mass function variations. Assuming a black hole model, we derive black hole masses for the sample of galaxies. In two galaxies, NGC 4458 and NGC 4660, the data suggest significantly overmassive black holes, while in most others only upper limits are obtained. We also show that the level of M/L enhancements we see in these early-type galaxy nuclei are consistent with the larger enhancements seen in ultracompact dwarf galaxies (UCDs), supporting the scenario where massive UCDs are created by stripping galaxies of these masses.

  1. Immune system development during early childhood in tropical Latin America: evidence for the age-dependent down regulation of the innate immune response.

    Science.gov (United States)

    Teran, Rommy; Mitre, Edward; Vaca, Maritza; Erazo, Silvia; Oviedo, Gisela; Hübner, Marc P; Chico, Martha E; Mattapallil, Joseph J; Bickle, Quentin; Rodrigues, Laura C; Cooper, Philip J

    2011-03-01

    The immune response that develops in early childhood underlies the development of inflammatory diseases such as asthma and there are few data from tropical Latin America (LA). This study investigated the effects of age on the development of immunity during the first 5 years of life by comparing innate and adaptive immune responses in Ecuadorian children aged 6-9 months, 22-26 months, and 48-60 months. Percentages of naïve CD4+ T cells declined with age while those of memory CD4(+) and CD8(+) T cells increased indicating active development of the immune system throughout the first five years. Young infants had greater innate immune responses to TLR agonists compared to older children while regulatory responses including SEB-induced IL-10 and percentages of FoxP3(+) T-regulatory cells decreased with age. Enhanced innate immunity in early life may be important for host defense against pathogens but may increase the risk of immunopathology. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Isotopic and anatomical evidence of an herbivorous diet in the Early Tertiary giant bird Gastornis. Implications for the structure of Paleocene terrestrial ecosystems

    Science.gov (United States)

    Angst, D.; Lécuyer, C.; Amiot, R.; Buffetaut, E.; Fourel, F.; Martineau, F.; Legendre, S.; Abourachid, A.; Herrel, A.

    2014-04-01

    The mode of life of the early Tertiary giant bird Gastornis has long been a matter of controversy. Although it has often been reconstructed as an apex predator feeding on small mammals, according to other interpretations, it was in fact a large herbivore. To determine the diet of this bird, we analyze here the carbon isotope composition of the bone apatite from Gastornis and contemporaneous herbivorous mammals. Based on 13C-enrichment measured between carbonate and diet of carnivorous and herbivorous modern birds, the carbonate δ13C values of Gastornis bone remains, recovered from four Paleocene and Eocene French localities, indicate that this bird fed on plants. This is confirmed by a morphofunctional study showing that the reconstructed jaw musculature of Gastornis was similar to that of living herbivorous birds and unlike that of carnivorous forms. The herbivorous Gastornis was the largest terrestrial tetrapod in the Paleocene biota of Europe, unlike the situation in North America and Asia, where Gastornis is first recorded in the early Eocene, and the largest Paleocene animals were herbivorous mammals. The structure of the Paleocene terrestrial ecosystems of Europe may have been similar to that of some large islands, notably Madagascar, prior to the arrival of humans.

  3. A Low Mass for Mars from Jupiter's Early Gas-Driven Migration

    Science.gov (United States)

    Walsh, Kevin J.; Morbidelli, Alessandro; Raymond, Sean N.; O'Brien, David P.; Mandell, Avi M.

    2011-01-01

    Jupiter and Saturn formed in a few million years from a gas-dominated protoplanetary disk, and were susceptible to gas-driven migration of their orbits on timescales of only approximately 100,000 years. Hydrodynamic simulations show that these giant planets can undergo a two-stage, inward-then-outward, migration. The terrestrial planets finished accreting much later and their characteristics, including Mars' small mass, are best reproduced by starting from a planetesimal disk with an outer edge at about one astronomical unit from the Sun (1 AU is the Earth-Sun distance). Here we report simulations of the early Solar System that show how the inward migration of Jupiter to 1.5 AU, and its subsequent outward migration, lead to a planetesimal disk truncated at 1 AU; the terrestrial planets then form from this disk over the next 30-50 million years, with an Earth/Mars mass ratio consistent with observations. Scattering by Jupiter initially empties but then repopulates the asteroid belt, with inner-belt bodies originating between 1 and 3 AU and outer-belt bodies originating between and beyond the giant planets. This explains the significant compositional differences across the asteroid belt. The key aspect missing from previous models of terrestrial planet formation is the substantial radial migration of the giant planets, which suggests that their behaviour is more similar to that inferred for extrasolar planets than previously thought.

  4. Father involvement in early child-rearing and behavioural outcomes in their pre-adolescent children: evidence from the ALSPAC UK birth cohort

    Science.gov (United States)

    Redshaw, Maggie; Savage-McGlynn, Emily; Quigley, Maria A

    2016-01-01

    Objective To explore the nature of paternal involvement in early child-rearing adopting a social developmental perspective, and estimate its effect on behavioural outcomes of children aged 9 and 11 years. Setting The data come from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort recruited in the former county of Avon in the southwest of England. Participants Out of the 14 701 children in this cohort who were alive at 1 year, 10 440 children were living with both parents at 8 months and were therefore eligible. Outcome data were available for 6898 children at 9 years and 6328 children at 11 years. Main exposure Paternal involvement was measured using factor scores obtained through factor analysis of fathers’ responses on their participation in, understanding of, and feelings about their child's early upbringing. Outcome Behavioural problems were measured using the Strengths and Difficulties Questionnaire (SDQ) total difficulties score. Results 3 factors were identified in the factor analysis: Factor 1 described fathers’ emotional response to the child; factor 2 measured the frequency of fathers’ involvement in domestic and childcare activities; factor 3 characterised fathers’ feelings of security in their role as parent and partner. Children of fathers with high scores on factors 1 and 3 had 14% (OR 0.86, 95% CI 0.79 to 0.94, p=0.001) and 13% (OR 0.87, 95% CI 0.79 to 0.96, p=0.006), respectively, lower adjusted odds of behavioural problems at 9 years. Factors 1 and 3 were associated with comparable reduction in adjusted odds of behavioural problems at 11 years (OR 0.89, 95% CI 0.81 to 0.98, p=0.017 and OR 0.89, 95% CI 0.81 to 0.99, p=0.034, respectively). Factor 2 was not associated with the outcome. Conclusions Psychological and emotional aspects of paternal involvement in children's early upbringing, particularly how new fathers see themselves as parents and adjust to the role, rather than the quantity of direct

  5. Father involvement in early child-rearing and behavioural outcomes in their pre-adolescent children: evidence from the ALSPAC UK birth cohort.

    Science.gov (United States)

    Opondo, Charles; Redshaw, Maggie; Savage-McGlynn, Emily; Quigley, Maria A

    2016-11-22

    To explore the nature of paternal involvement in early child-rearing adopting a social developmental perspective, and estimate its effect on behavioural outcomes of children aged 9 and 11 years. The data come from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort recruited in the former county of Avon in the southwest of England. Out of the 14 701 children in this cohort who were alive at 1 year, 10 440 children were living with both parents at 8 months and were therefore eligible. Outcome data were available for 6898 children at 9 years and 6328 children at 11 years. Paternal involvement was measured using factor scores obtained through factor analysis of fathers' responses on their participation in, understanding of, and feelings about their child's early upbringing. Behavioural problems were measured using the Strengths and Difficulties Questionnaire (SDQ) total difficulties score. 3 factors were identified in the factor analysis: Factor 1 described fathers' emotional response to the child; factor 2 measured the frequency of fathers' involvement in domestic and childcare activities; factor 3 characterised fathers' feelings of security in their role as parent and partner. Children of fathers with high scores on factors 1 and 3 had 14% (OR 0.86, 95% CI 0.79 to 0.94, p=0.001) and 13% (OR 0.87, 95% CI 0.79 to 0.96, p=0.006), respectively, lower adjusted odds of behavioural problems at 9 years. Factors 1 and 3 were associated with comparable reduction in adjusted odds of behavioural problems at 11 years (OR 0.89, 95% CI 0.81 to 0.98, p=0.017 and OR 0.89, 95% CI 0.81 to 0.99, p=0.034, respectively). Factor 2 was not associated with the outcome. Psychological and emotional aspects of paternal involvement in children's early upbringing, particularly how new fathers see themselves as parents and adjust to the role, rather than the quantity of direct involvement in childcare, is associated with positive behavioural outcomes in children

  6. The mantle source of island arc magmatism during early subduction: Evidence from Hf isotopes in rutile from the Jijal Complex (Kohistan arc, Pakistan)

    Science.gov (United States)

    Ewing, Tanya A.; Müntener, Othmar

    2018-05-01

    The Cretaceous-Paleogene Kohistan arc complex, northern Pakistan, is renowned as one of the most complete sections through a preserved paleo-island arc. The Jijal Complex represents a fragment of the plutonic roots of the Kohistan arc, formed during its early intraoceanic history. We present the first Hf isotope determinations for the Jijal Complex, made on rutile from garnet gabbros. These lithologies are zircon-free, but contain rutile that formed as an early phase. Recent developments in analytical capabilities coupled with a careful analytical and data reduction protocol allow the accurate determination of Hf isotope composition for rutile with <30 ppm Hf for the first time. Rutile from the analysed samples contains 5-35 ppm Hf, with sample averages of 13-17 ppm. Rutile from five samples from the Jijal Complex mafic section, sampling 2 km of former crustal thickness, gave indistinguishable Hf isotope compositions with εHf(i) ranging from 11.4 ± 3.2 to 20.1 ± 5.7. These values are within error of or only slightly more enriched than modern depleted mantle. The analysed samples record variable degrees of interaction with late-stage melt segregations, which produced symplectitic overprints on the main mineral assemblage as well as pegmatitic segregations of hydrous minerals. The indistinguishable εHf(i) across this range of lithologies demonstrates the robust preservation of the Hf isotope composition of rutile. The Hf isotope data, combined with previously published Nd isotope data for the Jijal Complex garnet gabbros, favour derivation from an inherently enriched, Indian Ocean type mantle. This implies a smaller contribution from subducted sediments than if the source was a normal (Pacific-type) depleted mantle. The Jijal Complex thus had only a limited recycled continental crustal component in its source, and represents a largely juvenile addition of new continental crust during the early phases of intraoceanic magmatism. The ability to determine the Hf

  7. Psychological outcomes in midadulthood associated with mother's child-rearing attitudes in early childhood--evidence from the 1970 British birth cohort.

    Science.gov (United States)

    Flouri, Eirini

    2004-02-01

    This study used longitudinal data from the 1970 British Cohort Study (BCS70) to examine the role of mother's child-rearing attitudes assessed when cohort members were aged 5 in children's psychological well-being (psychological functioning, psychological distress, life satisfaction and self-efficacy) at age 30. Although at the multivariate level mother's childrearing attitudes were not related to sons' psychological well-being in adult life, in daughters self-efficacy and life satisfaction at age 30 were related to mother's anti-child autonomy attitudes and mother's non-authoritarian child-rearing attitudes, respectively. In addition, mother's non-authoritarian childrearing attitudes had a protective effect against later psychological distress and low self-efficacy in daughters who had experienced significant material disadvantage in early childhood.

  8. The Impact of Health Changes on Labor Supply: Evidence from Merged Data on Individual Objective Medical Diagnosis Codes and Early Retirement Behavior

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper; Kallestrup-Lamb, Malene

    2012-01-01

    The justification bias in the estimated impact of health shocks on retirement is mitigated by using objective health measures from a large, register-based longitudinal data set including medical diagnosis codes, along with labor market status, financial, and socio-economic variables. The duration...... until retirement is modeled using single and competing risk specifications, observed and unobserved heterogeneity, and flexible baseline hazards. Wealth is used as a proxy for elapsed duration to mitigate the potential selection bias stemming from conditioning on initial participation. The competing...... risk specification distinguishes complete multi-period routes to retirement, such as unemployment followed by early retirement. A result on comparison of coefficients across all states is offered. The empirical results indicate a strong impact of health changes on retirement, and hence a large...

  9. A- and I-type metagranites from the North Shahrekord Metamorphic Complex, Iran: Evidence for Early Paleozoic post-collisional magmatism

    Science.gov (United States)

    Badr, Afsaneh; Davoudian, Ali Reza; Shabanian, Nahid; Azizi, Hossein; Asahara, Yoshihiro; Neubauer, Franz; Dong, Yunpeng; Yamamoto, Koshi

    2018-02-01

    The North Shahrekord Metamorphic Complex (NSMC) of the central Sanandaj-Sirjan Zone (SaSZ) consists of metagranitoid bodies, which were metamorphosed within high pressure-low temperature conditions. Whole rock chemistry shows relatively high amounts of SiO2 (65-77 wt%) and Al2O3 (12-15 wt%), low amounts of Nb, P, Sr, Ti, a high ratio of Ga/Al (4-9) and a negative Eu anomaly. The chemical compositions of metagranites are reasonably similar to A- and I-type granites. U-Pb zircon ages of three samples of metagranites indicate that crystallization of the granites occurred at 521.6 ± 9.1 to 513.5 ± 8.5 Ma, Middle Cambrian. The initial 87Sr/86Sr and 143Nd/144Nd ratios of samples vary from 0.7057-0.7239 and 0.511801-0.511890, respectively. High initial 87Sr/86Sr ratios and low εNd(t) values (- 3.39 to - 1.07) associated with high ratios of 206Pb/204Pb(t) = 17.8557-18.8045, 207Pb/204Pb(t) = 15.6721-15.7220, and 208Pb/204Pb(t) = 37.7490-38.4468 infer a significant contribution of continental crust in generating the source magma of the metagranite bodies. The results reveal that the metagranites were mainly produced through mixing of basaltic melts with components similar to metasedimentary sources. The new results show that crystallization of the metagranites occurred in Early Paleozoic times and much earlier than break-up and drifting of the SaSZ from the Arabian plate, suggesting that the metagranites were mainly produced in the western Iran after the closure of the Proto-Tethys Ocean. This model is consistent with the previously suggested models for formation of an Early Paleozoic granitoid belt along the northern rim of Gondwana.

  10. Contribution of early impact events to metal-silicate separation, thermal annealing, and volatile redistribution: Evidence in the Pułtusk H chondrite

    Science.gov (United States)

    Krzesińska, Agata M.

    2017-11-01

    Three-dimensional X-ray tomographic reconstructions and petrologic studies reveal voluminous accumulations of metal in Pułtusk H chondrite. At the contact of these accumulations, the chondritic rock is enriched in troilite. The rock contains plagioclase-rich bands, with textures suggesting crystallization from melt. Unusually large phosphates are associated with the plagioclase and consist of assemblages of merrillite, and fluorapatite and chlorapatite. The metal accumulations were formed by impact melting, rapid segregation of metal-sulfide melt and the incorporation of this melt into the fractured crater basement. The impact most likely occurred in the early evolution of the H chondrite parent body, when post-impact heat overlapped with radiogenic heat. This enabled slow cooling and separation of the metallic melt into metal-rich and sulfide-rich fractions. This led to recrystallization of chondritic rock in contact with the metal accumulations and the crystallization of shock melts. Phosphorus was liberated from the metal and subsumed by the silicate shock melt, owing to oxidative conditions upon slow cooling. The melt was also a host for volatiles. Upon further cooling, phosphorus reacted with silicates leading to the formation of merrillite, while volatiles partitioned into the residual halogen-rich, dry fluid. In the late stages, the fluid altered merrillite to patchy Cl/F-apatite. The above sequence of alterations demonstrates that impact during the early evolution of chondritic parent bodies might have contributed to local metal segregation and silicate melting. In addition, postshock conditions supported secondary processes: compositional/textural equilibration, redistribution of volatiles, and fluid alterations.

  11. Providing Family Planning Services at Primary Care Organizations after the Exclusion of Planned Parenthood from Publicly Funded Programs in Texas: Early Qualitative Evidence.

    Science.gov (United States)

    White, Kari; Hopkins, Kristine; Grossman, Daniel; Potter, Joseph E

    2017-10-20

    To explore organizations' experiences providing family planning during the first year of an expanded primary care program in Texas. Between November 2014 and February 2015, in-depth interviews were conducted with program administrators at 30 organizations: 7 women's health organizations, 13 established primary care contractors (e.g., community health centers, public health departments), and 10 new primary care contractors. Interviews addressed organizational capacities to expand family planning and integrate services with primary care. Interview transcripts were analyzed using a theme-based approach. Themes were compared across the three types of organizations. Established and new primary care contractors identified several challenges expanding family planning services, which were uncommon among women's health organizations. Clinicians often lacked training to provide intrauterine devices and contraceptive implants. Organizations often recruited existing clients into family planning services, rather than expanding their patient base, and new contractors found family planning difficult to integrate because of clients' other health needs. Primary care contractors frequently described contraceptive provision protocols that were not evidence-based. Many primary care organizations in Texas initially lacked the capacity to provide evidence-based family planning services that women's health organizations already provided. © Health Research and Educational Trust.

  12. The formation of giant planets and its effects on protoplanetary disks: the case of Jupiter and the Jovian Early Bombardment

    Science.gov (United States)

    Turrini, D.; ISSI Team "Vesta, the key to the origins of the Solar System"; EChO "Planetary Formation" Working Group

    The formation of giant planets is accompanied by a short but intense primordial bombardment \\citep{safronov69,weidenschilling75,weidenschilling01,turrini11}: the prototype for this class of events is the Jovian Early Bombardment (JEB) caused by the formation of Jupiter in the Solar System \\citep{turrini11,turrini12}. The JEB affected the collisional evolution of the minor bodies in the inner Solar System by inflicting mass loss to planetesimals \\citep{turrini12,turrini14a,turrini14b} due to cratering erosion and, at the same time, delivering water and volatile materials to the asteroid belt \\citep{turrini14b}. The JEB also resulted in a significant number of collisions between Jupiter and planetesimals formed over a wide orbital range, delivering volatile and refractory materials to the giant planet and its circumplanetary disk \\citep{turrini14c}. In this talk I'll discuss how the study of the effects of the JEB on Vesta can be used to constrain the early evolution of the Solar System \\citep{turrini14a,turrini14b} and how these constraints can, in turn, provide insight on the composition of Jupiter and of its satellites. Finally, I'll discuss the implications of the JEB model for extrasolar planets \\citep{turrini14c}.

  13. Evolution and early evidence of the impact of consumer-driven health plans: from e-commerce venture to health savings accounts.

    Science.gov (United States)

    Parente, Stephen T; Feldman, Roger

    2008-08-01

    Using results from peer-reviewed empirical analyses we describe the development and impact of the consumer-driven health plan market over the last 5 years. The results of these analyses show that consumers are responding to the financial incentives of these new health insurance benefits. Although the results may not always be what the consumer-driven health plan developers intended, there is clear evidence of 'consumerism', where individuals act in a way that generally increases their access to healthcare or investments, if the opportunity is present. Just as Medicare Part D enrollment demonstrated consumers could identify differences in prescription drug plans and make rational choices, so too are prospective patients able to function as consumers in the medical marketplace when give the opportunity.

  14. Marriage season, promptness of successful pregnancy and first-born sex ratio in a historical natural fertility population - evidence for sex-dependent early pregnancy loss?

    Science.gov (United States)

    Nonaka, K.; Desjardins, Bertrand; Charbonneau, Hubert; Légaré, Jacques; Miura, Teiji

    We investigated population-based vital records of the seventeenth and eighteenth century French Canadian population to assess the effects of marriage season on the outcome of the first births under natural fertility conditions (n=21,698 marriages). Promptness of the first successful conception after marriage differed according to marriage season; the proportion of marriages with a marriage-first birth interval of 8.0-10.0 months was lowest (34%) for marriages in August-October (P=0.001). Although the male/female sex ratio of the babies born with an interval of 8.0-10.0 months was generally higher (1.10) than those with an interval of 10.0-24.0 months (1.05), the marriages in August-October resulted in a significantly reduced sex ratio (0.96) among only the prompt conceptions (P=0.026). We discuss whether this seasonal reduction of the sex ratio could be partly explained by a clustered pregnancy loss of male zygotes in early pregnancy.

  15. Delayed discrimination of spatial frequency for gratings of different orientation: behavioral and fMRI evidence for low-level perceptual memory stores in early visual cortex.

    Science.gov (United States)

    Baumann, Oliver; Endestad, Tor; Magnussen, Svein; Greenlee, Mark W

    2008-07-01

    The concept of perceptual memory refers to the neural and cognitive processes underlying the storage of specific stimulus features such as spatial frequency, orientation, shape, contrast, and color. Psychophysical studies of perceptual memory indicate that observers can retain visual information about the spatial frequency of Gabor patterns independent of the orientation with which they are presented. Compared to discrimination of gratings with the same orientation, reaction times to orthogonally oriented gratings, however, increase suggesting additional processing. Using event-related fMRI we examined the pattern of neural activation evoked when subjects discriminated the spatial frequency of Gabors presented with the same or orthogonal orientation. Blood-oxygen level dependent BOLD fMRI revealed significantly elevated bilateral activity in visual areas (V1, V2) when the gratings to be compared had an orthogonal orientation, compared to when they had the same orientation. These findings suggest that a change in an irrelevant stimulus dimension requires additional processing in primary and secondary visual areas. The finding that the task-irrelevant stimulus property (orientation) had no significant effect on the prefrontal and intraparietal cortex supports a model of working memory in which discrimination and retention of basic stimulus dimensions is based on low-level perceptual memory stores that are located at an early stage in the visual process. Our findings suggest that accessing different stores requires time and has higher metabolic costs.

  16. Family Income and Material Deprivation: Do They Matter for Sleep Quality and Quantity in Early Life? Evidence From a Longitudinal Study.

    Science.gov (United States)

    Barazzetta, Marta; Ghislandi, Simone

    2017-03-01

    The aim of this article is to investigate the determinants of sleeping patterns in children up to age 9 on a large and geographically homogeneous sample of British children and parents, focusing in particular on the role of economic and social factors, specifically on income. The data of this study come from the Avon Longitudinal Study of Parents and Children, a long-term health research project that recruited over 14000 pregnant women who were due to give birth between April 1991 and December 1992 in Bristol and its surrounding areas, including some of Somerset and Gloucestershire. Logistic regression models for the sleep problem dummies and log-linear models for the sleep quantity. One additional item in the material deprivation index is associated to an increase of around 10-20% in the odds of having at least 1 sleep problem. Similarly, children from the richest families are less likely to have any sleep problem up to 115 months (around 20% reduction in the odds). Mother's characteristics (i.e., education and mental health in the pregnancy period) are also significant predictors. Sleep quantity does not vary much and is not sensitive to socioeconomic factors. Exposure to income-related inequalities affects child sleep. Further research is needed to understand if sleep in early life influences future health and economic trajectories. © Sleep Research Society 2016. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  17. New evidence of an early Pridoli barrier reef in the southern part of the Baltic Silurian basin based on three-dimensional seismic survey, Lithuania

    Directory of Open Access Journals (Sweden)

    Donatas Kaminskas

    2015-02-01

    Full Text Available Reefs and a barrier reef have been newly identified and mapped by three-dimensional (3D seismic survey in Lithuania. Seismic data analysis has allowed the size and geometry of these reefs to be determined. The largest reefs occur at Pavasaris and South Bliudziai. They have a similar shape and are about 1.5 km long and 1 km wide. A circle-shaped smaller patch reef at North Bliudziai is 1 km in diameter. The overall heights of the studied structures do not exceed 30–40 m. The reefs consist of coarse-grained bioclastic stromatoporoid limestone. A barrier reef rising structurally from SW to NE was established in the west of the mapped area. The stratigraphic position (early Minija Regional Stage and lateral distribution of the barrier reef suggest it started to form earlier than the group of patch reefs. The development of patch reefs was related to the transgression of the Silurian Baltic basin.

  18. Dynamics of immediate early gene and neuropeptide gene response to prolonged immobilization stress: evidence against a critical role of the termination of exposure to the stressor.

    Science.gov (United States)

    Trnecková, Lenka; Rotllant, David; Klenerová, Vera; Hynie, Sixtus; Armario, Antonio

    2007-02-01

    Stress-induced expression of immediate early genes (IEGs) appears to be transient even if the exposure to the stressor persists. However, there are some exceptions which suggest that particular characteristics of stressors can affect the dynamics of IEG expression. We studied in selected telencephalic, diencephalic and brainstem regions the mRNA levels of two clearly distinct IEGs (c-fos and arc) during prolonged exposure to a severe stressor such as immobilization (IMO) and after releasing the rats from the situation. Although regional differences were observed with the two IEGs, overall, c-fos mRNA levels progressively declined over the course of 4 h of continuous exposure to IMO, whereas arc mRNA levels were maintained at high levels in the brain regions that express this gene under stress (telencephalon). Levels of CRF hnRNA in the hypothalamus paraventricular nucleus only slightly declined during prolonged exposure to IMO. Surprisingly, termination of exposure to IMO did not modify CRF gene expression in the paraventricular nucleus or the pattern of IEGs expression, with the exception of c-fos in the lateral septum. Thus, putative signals associated to the termination of exposure to IMO were unable to modify either IEG expression in most brain areas or CRF gene expression in the paraventricular nucleus.

  19. Evidence of the preferential use of disease prototypes over case exemplars among early year one medical students prior to and following diagnostic training.

    Science.gov (United States)

    Papa, Frank J; Li, Feiming

    2015-12-01

    Two core dual processing theory (DPT) System I constructs (Exemplars and Prototypes) were used to: 1) formulate a training exercise designed to improve diagnostic performance in year one medical students, and 2) explore whether any observed performance improvements were associated with preferential use of exemplars or prototypes. With IRB approval, 117 year one medical students participated in an acute chest pain diagnostic training exercise. A pre- and post-training test containing the same 27 case vignettes was used to determine if the subjects' diagnostic performance improved via training in both exemplars and prototypes. Exemplar and Prototype theory was also used to generate a unique typicality estimate for each case vignette. Because these estimates produce different performance predictions, differences in the subjects' observed performance would make it possible to infer whether subjects were preferentially using Exemplars or Prototypes. Pre- vs. post-training comparison revealed a significant performance improvement; t=14.04, pmid typical vignettes: t=4.94, pleast typical: t=5.16, pmid typical: t=2.94, pleast typical: t=6.64, ptheory than Exemplar theory. DPT is useful in designing and evaluating the utility of new approaches to diagnostic training, and, investigating the cognitive factors driving diagnostic capabilities among early medical students.

  20. ACCRETION AND PRESERVATION OF D-RICH ORGANIC PARTICLES IN CARBONACEOUS CHONDRITES: EVIDENCE FOR IMPORTANT TRANSPORT IN THE EARLY SOLAR SYSTEM NEBULA

    International Nuclear Information System (INIS)

    Remusat, L.; Guan, Y.; Wang, Y.; Eiler, J. M.

    2010-01-01

    We have acquired NanoSIMS images of the matrices of CI, CM, and CR carbonaceous chondrites to study, in situ, the organic matter trapped during the formation of their parent bodies. D/H ratio images reveal the occurrence of D-rich hot spots, constituting isolated organic particles. Not all the organic particles are D-rich hot spots, indicating that at least two kinds of organic particles have been accreted in the parent bodies. Ratio profiles through D-rich hot spots indicate that no significant self-diffusion of deuterium occurs between the D-rich organic matter and the depleted hydrous minerals that are surrounding them. This is not the result of a physical shielding by any constituent of the chondrites. Ab initio calculations indicate that it cannot be explained by isotopic equilibrium. Then it appears that the organic matter that is extremely enriched in D does not exchange with the hydrous minerals, or this exchange is so slow that it is not significant over the 4.5 billion year history on the parent body. If we consider that the D-rich hot spots are the result of an exposure to intense irradiation, then it appears that carbonaceous chondrites accreted organic particles that have been brought to different regions of the solar nebula. This is likely the result of important radial and vertical transport in the early solar system.

  1. Dissociation between implicit and explicit manifestations of awareness in early stage dementia: evidence from the emotional Stroop effect for dementia-related words.

    Science.gov (United States)

    Martyr, Anthony; Clare, Linda; Nelis, Sharon M; Roberts, Judith L; Robinson, Julia U; Roth, Ilona; Markova, Ivana S; Woods, Robert T; Whitaker, Christopher J; Morris, Robin G

    2011-01-01

    To determine whether people with dementia (PwD), and carers of PwD, show a processing bias to dementia-related words in an emotional Stroop task, and if so, whether the presence of such a bias is related to level of explicit awareness of the condition. Seventy-nine people with early stage Alzheimer's disease (AD), vascular or mixed dementia, and their carers, completed an emotional Stroop task. Time taken to colour-name dementia-related and neutral words was compared within and between groups. Additionally, as a comparison, ratings of the awareness of the condition shown by PwD were made on the basis of a detailed interview with each PwD and his/her carer. PwD and carers showed the same level of increase in response times to salient compared to neutral words. In the PwD this effect was unrelated to the degree of awareness that they demonstrated regarding the condition. The emotional Stroop effect in response to dementia-related words in PwD indicates that preserved implicit awareness of the condition can be elicited even where there is reduced explicit awareness. Copyright © 2010 John Wiley & Sons, Ltd.

  2. Association between economic growth and early childhood undernutrition: evidence from 121 Demographic and Health Surveys from 36 low-income and middle-income countries.

    Science.gov (United States)

    Vollmer, Sebastian; Harttgen, Kenneth; Subramanyam, Malavika A; Finlay, Jocelyn; Klasen, Stephan; Subramanian, S V

    2014-04-01

    Economic growth is widely regarded as a necessary, and often sufficient, condition for the improvement of population health. We aimed to assess whether macroeconomic growth was associated with reductions in early childhood undernutrition in low-income and middle-income countries. We analysed data from 121 Demographic and Health Surveys from 36 countries done between Jan 1, 1990, and Dec 31, 2011. The sample consisted of nationally representative cross-sectional surveys of children aged 0-35 months, and the outcome variables were stunting, underweight, and wasting. The main independent variable was per-head gross domestic product (GDP) in constant prices and adjusted for purchasing power parity. We used logistic regression models to estimate the association between changes in per-head GDP and changes in child undernutrition outcomes. Models were adjusted for country fixed effects, survey-year fixed effects, clustering, and demographic and socioeconomic covariates for the child, mother, and household. Sample sizes were 462,854 for stunting, 485,152 for underweight, and 459,538 for wasting. Overall, 35·6% (95% CI 35·4-35·9) of young children were stunted (ranging from 8·7% [7·6-9·7] in Jordan to 51·1% [49·1-53·1] in Niger), 22·7% (22·5-22·9) were underweight (ranging from 1·8% [1·3-2·3] in Jordan to 41·7% [41·1-42·3] in India), and 12·8% (12·6-12·9) were wasted (ranging from 1·2% [0·6-1·8] in Peru to 28·8% [27·5-30·0] in Burkina Faso). At the country level, no association was seen between average changes in the prevalence of child undernutrition outcomes and average growth of per-head GDP. In models adjusted only for country and survey-year fixed effects, a 5% increase in per-head GDP was associated with an odds ratio (OR) of 0·993 (95% CI 0·989-0·995) for stunting, 0·986 (0·982-0·990) for underweight, and 0·984 (0·981-0·986) for wasting. ORs after adjustment for the full set of covariates were 0·996 (0·993-1·000) for stunting, 0

  3. Isolation of hemopoietic stem cell subsets from murine bone marrow: II. Evidence for an early precursor of day-12 CFU-S and cells associated with radioprotective ability

    International Nuclear Information System (INIS)

    Ploemacher, R.E.; Brons, N.H.

    1988-01-01

    Counterflow centrifugal elutriation (CCE) in combination with plastic adherence and fluorescence-activated cell sorting were used consecutively to enrich functionally different subpopulations of pluripotent hemopoietic stem cells (HSC) from mouse bone marrow. The nonadherent CCE fractions were labeled with wheat germ agglutinin (WGA)-fluorescein isothiocyanate (FITC) and sorted according to differences in fluorescence within various windows on the basis of forward (FLS) and perpendicular (PLS) light scatter. The sorted cells were then assayed for their (1) in vivo colony-forming ability (day-7 and day-12 spleen colony-forming units [CFU-S]), (2) radioprotective ability (RPA; 30-day survival), and (3) their ability to repopulate the bone marrow or spleen over a 13-day period with day-12 CFU-S, granulocyte-macrophage colony-forming units (CFU-GM), nucleated cells, or cells associated with RPA. The highest incidence of day-12 CFU-S and cells with RPA was obtained by sorting the most WGA-positive cells with relatively high PLS (enrichment, 50- to 200-fold), lowering the effective dose (ED 50/30) to an average of 80 cells. The separative procedure enabled hemopoietic stem cells that repopulate both bone marrow and spleen with secondary RPA cells, CFU-S-12, and CFU-GM to be enriched and separated from part of the RPA cells, CFU-S-12, and cells that reconstitute the cellularity of bone marrow and spleen. These data suggest that cells generating both day-12 CFU-S and RPA cells differ from day-12 CFU-S and RPA cells themselves on the basis of PLS characteristics and affinity for WGA. Such early stem cells have also been detected in sorted fractions meeting the FLS/PLS characteristics of lymphocytes

  4. Late Paleozoic-Early Mesozoic tectonic evolution of the Paleo-Asian Ocean: geochronological and geochemical evidence from granitoids in the northern margin of Alxa, Western China

    Science.gov (United States)

    Sha, Xin; Wang, Jinrong; Chen, Wanfeng; Liu, Zheng; Zhai, Xinwei; Ma, Jinlong; Wang, Shuhua

    2018-03-01

    The Paleo-Asian Ocean (Southern Mongolian Ocean) ophiolitic belts and massive granitoids are exposed in the Alxa block, in response to oceanic subduction processes. In this work, we report petrographic, geochemical, and zircon U-Pb age data of some granitoid intrusions from the northern Alxa. Zircon U-Pb dating for the quartz diorite, tonalite, monzogranite, and biotite granite yielded weighted mean 206Pb/238U a