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Sample records for kyr revising earlier

  1. 75 FR 47316 - National Science Board; Sunshine Act Meetings; Notice (Subject Matter Revised From Earlier Notice)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-05

    ... National Science Board; Sunshine Act Meetings; Notice (Subject Matter Revised From Earlier Notice) The... National Science Board business and other matters specified, as follows: Date and Time: August 12, 2010, at 3 p.m. EDT. Subject Matter: Review and Discussion of Current Mid-Scale Research Funding Support...

  2. Revision of Ernst Antevs' New England Varve Chronology: A Record of Meltwater Production and Southeastern LIS Recession: 18.2-12.5 kyr BP (Invited)

    NASA Astrophysics Data System (ADS)

    Ridge, J. C.

    2013-12-01

    New varve cores and 54 radiocarbon ages, have allowed the correction, closure of a gap, calibration, and expansion of Ernst Antevs' (1922) New England Varve Chronology from sediments of glacial Lake Hitchcock and it's successors in the Connecticut Valley of western New England (northeastern U.S.A.). The continuous 5659-yr chronology (18.2-12.5 kyr BP) has been renumbered as the North American Varve Chronology. Glacial varve thickness (18.2-13.7 kyr BP) documents abrupt changes in meltwater production related to varying ablation rate (summer climate) that is linked to ice sheet recession rates and advances, i.e. cold intervals are times of thin varves and slower ice recession or glacial readvances. To take advantage of the varve-climate relationship it is necessary to identify non-climatic events that can cause varve thickness to change. This includes sudden changes in lake level and flood events triggered by the abrupt drainage of tributary glacial lakes. A chronology of ice recession for intervals terminated by four stillstands and readvances of 1-2 century durations have been determined for the Connecticut Valley (from S to N): 50-100 m/yr in northern Connecticut to southern Massachusetts; Chicopee Readvance; 30-40 m/yr in central Mass.; Hatfield event; 80-90 m/yr from northern Mass. to central New Hampshire; North Charlestown end moraines; 300 m/yr to northern N.H.; Littleton Readvance; >300 m/yr to Quebec. Meltwater produced by ice recession of 300 m/yr modeled as a receding 1-bar ice sheet profile (from 100 km up ice near ELA to margin, valley width of 80 km, glacier flow rate of 200 m/yr at ELA) would be a minimum glacial meltwater discharge in the Connecticut Valley of ~90 x 109 m3/yr. This is ~10X the modern Conn. River discharge at Walpole, NH compressed almost entirely to the melt season. Non-glacial varves deposited after ice receded from the basin (13.7-12.5 kyr BP) also document climate change as a result of varve thickness varying with changes in

  3. The Sima de los Huesos hominids date to beyond U/Th equilibrium (>350 kyr) and perhaps to 400-500 kyr: New radiometric dates

    USGS Publications Warehouse

    Bischoff, J.L.; Shamp, D.D.; Aramburu, Arantza; Arsuaga, J.L.; Carbonell, E.; Bermudez de Castro, Jose Maria

    2003-01-01

    The Sima de los Huesos site of the Atapuerca complex near Burgos, Spain contains the skeletal remains of at least 28 individuals in a mud breccia underlying an accumulation of the Middle Pleistocene cave bear (U. deningeri). Earlier dating estimates of 200 to 320 kyr were based on U-series and ESR methods applied to bones, made inaccurate by unquantifiable uranium cycling. We report here on a new discovery within the Sima de los Huesos of human bones stratigraphically underlying an in situ speleothem. U-series analyses of the speleothem shows the lower part to be at isotopic U/Th equilibrium, translating to a firm lower limit of 350 kyr for the SH hominids. Finite dates on the upper part suggest a speleothem growth rate of c. 1 cm/32 kyr. This rate, along with paleontological constraints, place the likely age of the hominids in the interval of 400 to 600 kyr. ?? 2002 Elsevier Science Ltd. All rights reserved.

  4. An earlier de motu cordis.

    PubMed Central

    Daly, Walter J.

    2004-01-01

    Thirteenth century medical science, like medieval scholarship in general, was directed at reconciliation of Greek philosophy/science with prevailing medieval theology and philosophy. Peter of Spain [later Pope John XXI] was the leading medical scholar of his time. Peter wrote a long book on the soul. Imbedded in it was a chapter on the motion of the heart. Peter's De Motu was based on his own medical experience and Galen's De Usu Partium and De Usu Respirationis and De Usu Pulsuum. This earlier De Motu defines a point on the continuum of intellectual development leading to us and into the future. Thirteenth century scholarship relied on past authority to a degree that continues to puzzle and beg explanation. Images Fig. 1 PMID:17060956

  5. Variations in flow and transport in thick desert vadose zones in response to paleoclimatic forcing (0-90 kyr): Field measurements, modeling, and uncertainties

    USGS Publications Warehouse

    Scanlon, B.R.; Keese, K.; Reedy, R.C.; Simunek, J.; Andraski, B.J.

    2003-01-01

    An understanding of unsaturated flow and potential recharge in interdrainage semiarid and arid regions is critical for quantification of water resources and contaminant transport. We evaluated system response to paleoclimatic forcing using water potential and Cl profiles and modeling of nonisothermal liquid and vapor flow and Cl transport at semiarid (High Plains, Texas) and arid (Chihuahuan Desert, Texas; Amargosa Desert, Nevada) sites. Infiltration in response to current climatic forcing is restricted to the shallow (???0.3-3 m) subsurface. Subsurface Cl accumulations correspond to time periods of 9-90 kyr. Bulge-shaped Cl profiles generally represent accumulation during the Holocene (9-16 kyr). Lower Cl concentrations at depth reflect higher water fluxes (0.04-8.4 mm/yr) during the Pleistocene and earlier times. Low water potentials and upward gradients indicate current drying conditions. Nonisothermal liquid and vapor flow simulations indicate that upward flow for at least 1-2 kyr in the High Plains and for 1.2-16 kyr at the Chihuahuan and Amargosa desert sites is required to reproduce measured upward water potential gradients and that recharge is negligible (<0.1 mm/yr) in these interdrainage areas.

  6. Plio-Pleistocene time evolution of the 100-kyr cycle in marine paleoclimate records

    NASA Technical Reports Server (NTRS)

    Park, Jeffrey; Maasch, Kirk A.

    1993-01-01

    A new time-series analysis technique (called envelope inversion), which is based on multiple taper spectral analysis, is used to address the question of an abrupt versus a gradual onset of the 100-kyr ice-age periodicity in the middle Pleistocene. Three long (greater than 2.6 m.y.) time series from Deep Sea Drilling Project site 607 (midlatitude Atlantic) and Ocean Drilling Program site 677 (equatorial Pacific) were analyzed using delta(O-18) records. Results do not yield compelling evidence for an abrupt change in the 100-kyr delta(O-18) signal. Rather, the results suggest that the 100-kyr delta(O-18) cycle is phase-locked with the 124-kyr eccentricity cycle some 300-400 kyr prior to its late Pleistocene growth in amplitude and phase lock with the 95-kyr eccentricity cycle.

  7. Toward Explaining Earlier Retirement after 1970.

    ERIC Educational Resources Information Center

    Ippolito, Richard A.

    1990-01-01

    Rule changes in the social security system and pension plans suggest that labor force participation rates for men aged 55 to 64 fell by 20 percent from 1970 through 1986 because of the increase in social security benefits and a change in private pension rules encouraging earlier retirement. (Author/JOW)

  8. Euthanasia: why people want to die earlier.

    PubMed

    Seale, C; Addington-Hall, J

    1994-09-01

    The results from two surveys in England of relatives and others who knew people in samples drawn from death certificates are reported. The main focus is on a sample of 3696 people dying in 1990 in 20 health authorities, with supporting analysis from an earlier national sample of 639 people dying in 1987. The incidence of people saying they wanted to die sooner, and of requests for euthanasia are reported. Excluding a proportion who did not wish to express a view, or did not know the answer, about a quarter of both respondents and the people who died expressed the view that an earlier death would be, or would have been, preferable. 3.6% of people in the 1990 study were said to have asked for euthanasia at some point in the last year of life. The extent to which such views were determined by the experience of pain, other distressing symptoms, dependency and social and cultural factors such as religious belief and social class is explored. The finding that dependency was important in causing the feeling that an earlier death would have been better, as well as requests for euthanasia, is related to the public debate about euthanasia, which often contains the assertion that fear of pain is a dominant factor. Pain was found to be a significant factor in death from cancer, but not as important for other causes of death. Social class, place of residence of the deceased, and strength and type of religious faith were found to be largely insignificant in influencing feelings about an earlier death and requests for euthanasia.

  9. Calcium isotopes in caves as a proxy for aridity: Modern calibration and application to the 8.2 kyr event

    NASA Astrophysics Data System (ADS)

    Owen, R. A.; Day, C. C.; Hu, C.-Y.; Liu, Y.-H.; Pointing, M. D.; Blättler, C. L.; Henderson, G. M.

    2016-06-01

    We present the first study of Ca isotope cycling in a natural cave system, with measurements of bedrock, dripwater and recently formed carbonate, coupled to a first stalagmite time-series spanning the 8.2 kyr event. Dripwaters at Heshang Cave (Central China; 30°27‧N, 110°25‧E) are isotopically heavy relative to the dolomite bedrock, the result of prior calcite precipitation (PCP) occurring earlier in the drip flow path. A simple Rayleigh fractionation model quantifies the extent of PCP in the modern environment at 36% Ca removal. The observed in situ calcium isotope fractionation factor between dripwater and carbonate is Δ 44 / 42 Ca = - 0.63 ± 0.03 ‰ and does not vary during the annual cycle. Measurements of speleothem carbonate spanning the 8.2 kyr event show the response of Ca isotopes to changing climate. δ44/42Ca increases by 0.35‰ at the onset of the event, coeval with changes in δ18O and Mg/Ca, and remains high for 80 yr. This change is explained by decreased rainfall leading to increased PCP; an interpretation supported by established PCP proxies (Mg/Ca, Sr/Ca and Ba/Ca). Ca isotopes indicate that PCP increased to 60% Ca removal during the event, which, from application of a simple box model, suggests mean annual rainfall decreased by approximately a third in Central China during the 8.2 kyr event. The response of Ca isotopes across this event demonstrates their potential for the assessment of past conditions, including past dripwater flow rates and rainfall.

  10. Late Neogene East Asian monsoon: from winter to summer dominated sub-regime and periodicity transition from 100 kyr to 41 kyr

    NASA Astrophysics Data System (ADS)

    Li, F.; Rousseau, D.-D.; Wu, N.; Hao, Q.; Pei, Y.

    2009-04-01

    More and more evidence indicates that the onset of the East Asian (EA) monsoon can be traced back to the Oligocene-Miocene boundary (at about 23 Ma). However, the process of its evolution is still less well known until now. Here we investigate its late Neogene evolution by analyzing a terrestrial mollusk sequence, from the Chinese Loess Plateau (CLP), covering the period between 7.1 and 3.5 Ma. Considering the modern ecological requirements of these organisms, we were able to define two groups of cold-aridiphilous (CA) and thermo-humidiphilous (TH) species, representing the EA winter and summer monsoon variations, respectively, as previously defined in the Quaternary glacial-interglacial cycles. Variations in these two groups indicate two different monsoon dominated periods during 7.1-3.5 Ma. First, between 7.1 and 5.5 Ma, the EA winter monsoon, with a 100 kyr periodicity, was dominant. Second, between 5.1 and 4 Ma, the EA summer monsoon dominated, with a 41 kyr periodicity. Furthermore, our mollusk record yields valuable evidence for a late Miocene-Pliocene transition of about 400 kyr from winter monsoon dominated towards summer monsoon dominated, associated with a periodicity transition from weak 100 kyr to 41 kyr. The strengthened winter monsoon interval, with a 100 kyr periodicity, is coeval with orbital-scale global ice volume changes, in conjunction with the uplift of the Tibetan Plateau which probably reinforced the winter monsoon sub-regime. Conversely, closures of the Panama and Indonesian seaways, associated with changes in obliquity between 5.1 and 4 Ma, are probably major forcing factors for the observed dominant summer monsoon with 41 kyr frequency, favoring heat and moisture transports between low and high latitudes to allow TH mollusks to grow and develop in the CLP. The transition from a 100 kyr dominated interval towards a 41 kyr dominated one is contrary to the mid-Pleistocene transition (MPT), which corresponds to ice volume expansion at high

  11. Earlier snowmelt and warming lead to earlier but not necessarily more plant growth.

    PubMed

    Livensperger, Carolyn; Steltzer, Heidi; Darrouzet-Nardi, Anthony; Sullivan, Patrick F; Wallenstein, Matthew; Weintraub, Michael N

    2016-01-01

    Climate change over the past ∼50 years has resulted in earlier occurrence of plant life-cycle events for many species. Across temperate, boreal and polar latitudes, earlier seasonal warming is considered the key mechanism leading to earlier leaf expansion and growth. Yet, in seasonally snow-covered ecosystems, the timing of spring plant growth may also be cued by snowmelt, which may occur earlier in a warmer climate. Multiple environmental cues protect plants from growing too early, but to understand how climate change will alter the timing and magnitude of plant growth, experiments need to independently manipulate temperature and snowmelt. Here, we demonstrate that altered seasonality through experimental warming and earlier snowmelt led to earlier plant growth, but the aboveground production response varied among plant functional groups. Earlier snowmelt without warming led to early leaf emergence, but often slowed the rate of leaf expansion and had limited effects on aboveground production. Experimental warming alone had small and inconsistent effects on aboveground phenology, while the effect of the combined treatment resembled that of early snowmelt alone. Experimental warming led to greater aboveground production among the graminoids, limited changes among deciduous shrubs and decreased production in one of the dominant evergreen shrubs. As a result, we predict that early onset of the growing season may favour early growing plant species, even those that do not shift the timing of leaf expansion. PMID:27075181

  12. Earlier snowmelt and warming lead to earlier but not necessarily more plant growth

    PubMed Central

    Livensperger, Carolyn; Steltzer, Heidi; Darrouzet-Nardi, Anthony; Sullivan, Patrick F.; Wallenstein, Matthew; Weintraub, Michael N.

    2016-01-01

    Climate change over the past ∼50 years has resulted in earlier occurrence of plant life-cycle events for many species. Across temperate, boreal and polar latitudes, earlier seasonal warming is considered the key mechanism leading to earlier leaf expansion and growth. Yet, in seasonally snow-covered ecosystems, the timing of spring plant growth may also be cued by snowmelt, which may occur earlier in a warmer climate. Multiple environmental cues protect plants from growing too early, but to understand how climate change will alter the timing and magnitude of plant growth, experiments need to independently manipulate temperature and snowmelt. Here, we demonstrate that altered seasonality through experimental warming and earlier snowmelt led to earlier plant growth, but the aboveground production response varied among plant functional groups. Earlier snowmelt without warming led to early leaf emergence, but often slowed the rate of leaf expansion and had limited effects on aboveground production. Experimental warming alone had small and inconsistent effects on aboveground phenology, while the effect of the combined treatment resembled that of early snowmelt alone. Experimental warming led to greater aboveground production among the graminoids, limited changes among deciduous shrubs and decreased production in one of the dominant evergreen shrubs. As a result, we predict that early onset of the growing season may favour early growing plant species, even those that do not shift the timing of leaf expansion. PMID:27075181

  13. Earlier pupping in harbour seals, Phoca vitulina.

    PubMed

    Reijnders, Peter J H; Brasseur, Sophie M J M; Meesters, Erik H W G

    2010-12-23

    The annual reproductive cycle of most seal species is characterized by a tight synchrony of births. Typically, timing of birth shows little inter-annual variation. Here, however we show that harbour seals Phoca vitulina from the Wadden Sea (southeast North Sea) have shortened their yearly cycle, moving parturition to earlier dates since the early 1970s. Between 1974 and 2009, the birth date of harbour seals shifted on average by -0.71 d yr⁻¹, three and a half weeks (25 days) earlier, in the Dutch part of the Wadden Sea. Pup counts available for other parts of the Wadden Sea were analysed, showing a similar shift. To elucidate potential mechanism(s) for this shift in pupping phenology, possible changes in population demography, changes in maternal life-history traits and variations in environmental conditions were examined. It was deduced that the most likely mechanism was a shortening of embryonic diapause. We hypothesize that this could have been facilitated by an improved forage base, e.g. increase of small fishes, attributable to overfishing of large predator fishes and size-selective fisheries.

  14. Southwest Scandinavia, 40-15 kyr BP: palaeogeography and environmental change

    NASA Astrophysics Data System (ADS)

    Houmark-Nielsen, Michael; Kjær, Kurt Henrik

    2003-12-01

    Twelve palaeogeographical reconstructions illustrate environmental changes at the southwest rim of the Scandinavian Ice Sheet 40-15 kyr BP. Synchronised land, sea and glacier configurations are based on the lithostratigraphy of tills and intertill sediments. Dating is provided by optically stimulated luminescence and calibrated accelerator mass spectrometry radiocarbon.An interstadial sequence ca. 40-30 kyr BP with boreo-arctic proglacial fjords and subarctic flora and occasional glaciation in the Baltic was succeeded by a Last Glacial Maximum sequence ca. 30-20 kyr BP, with the closure of fjords and subsequent ice streams in glacial lake basins in Kattegat and the Baltic. Steadily flowing ice from Sweden bordered the Norwegian Channel Ice Stream. A deglaciation sequence ca. 20-15 kyr BP indicates the transgression of arctic waters, retreat of the Swedish ice and advance of Baltic ice streams succeeded by a return to interstadial conditions.When ameliorated ice-free conditions prevailed in maritime regions, glaciers advanced through the Baltic and when interstadial regimes dominated the Baltic, glaciers expanded off the Norwegian coast. The largest glacier extent was reached in the North Sea around 29 kyr BP, about 22 kyr BP in Denmark and ca. 18 kyr BP in the Baltic. Our model provides new data for future numerical and qualitative landform-based models. Copyright

  15. Model of earlier stage of universe's evolution

    NASA Astrophysics Data System (ADS)

    Bronnikov, K. A.; Melnikov, V. N.

    1987-06-01

    A scenario of the evolution of the universe has been proposed on the basis of an open nonsingular model symmetric in time and consisting of four stages: (1) spontaneous breaking of the conformal symmetry in unified theories of the Weinberg-Salam type with gravitational background, assuming that only a conformal Higgs field and a gravitational field have nonzero averages in vacuum; (2) spontaneous breaking of the gauge symmetry of a Higgs field in a gravitational field; (3) generation of particles in a nonsteady gravitational field; (4) variation of the effective gravitational coupling. The model is initially cold and then becomes hot as particles are generated or phase transition occurs. The dynamics of this model and the corresponding earlier stage of evolution are determined by the time term in the Einstein equations, analysis and solution of which require that deviation of the scalar field from classical and a possible attendant effect on the polarization of vacuum be taken into account. The essential underlying feature of this model is the concept of evolution from a perfect vacuum and thus a cold state with subsequent expansion from a nonsingular state and expansion implied by the cosmological constant.

  16. Can prion disease suspicion be supported earlier?

    PubMed Central

    Medina, Zaira; Balaguer, Rainier Rodriguez; Calleja, Jesus Higuera

    2011-01-01

    The subacute spongiform encephalopathies are prion diseases characterized by acute and rapid neurodegeneration that lead to the death of the patient within months to a few years. The epidemiology of CJD is complicated and the frequency in Mexico is unknown. We aim to describe the cases of prion disease in Mexico. Consecutive patients who met the diagnostic criteria by the WHO were enrolled. We describe 26 patients with clinical manifestations, imaging and laboratory studies compatible with prion disease. The mean age at onset was 52 years old. The main clinical manifestations were cognitive alterations (69%) followed by extrapyramidal movements (50%), abnormal cerebellar function (46%), behavioral alterations (46%), myoclonus (46%) and mood depression (23%), among other features. Half of the patients progressed rapidly to a state of akinetic mutism (53%). Only 2 (7.6%) patients had a family history of a similar disease. Time interval between onset and diagnosis varied between 71 days to 24 months, with a median of 6 months. The classical bilateral basal ganglia hyperintensities were present in the very early stage of the disease. Protein 14-3-3 immuneassay in the CSF was positive in all measured cases. Bilateral basal ganglia hyperintensities was the most important early finding, while protein 14-3-3 was a late finding and the results were usually obtained after the patient was discharged. Around 1.5 cases of CJD cases per year are reported in our country. When suspected, MRI can support the diagnosis earlier than other studies. PMID:21869605

  17. Terrestrial biosphere changes over the last 120 kyr

    NASA Astrophysics Data System (ADS)

    Hoogakker, B. A. A.; Smith, R. S.; Singarayer, J. S.; Marchant, R.; Prentice, I. C.; Allen, J. R. M.; Anderson, R. S.; Bhagwat, S. A.; Behling, H.; Borisova, O.; Bush, M.; Correa-Metrio, A.; de Vernal, A.; Finch, J. M.; Fréchette, B.; Lozano-Garcia, S.; Gosling, W. D.; Granoszewski, W.; Grimm, E. C.; Grüger, E.; Hanselman, J.; Harrison, S. P.; Hill, T. R.; Huntley, B.; Jiménez-Moreno, G.; Kershaw, P.; Ledru, M.-P.; Magri, D.; McKenzie, M.; Müller, U.; Nakagawa, T.; Novenko, E.; Penny, D.; Sadori, L.; Scott, L.; Stevenson, J.; Valdes, P. J.; Vandergoes, M.; Velichko, A.; Whitlock, C.; Tzedakis, C.

    2016-01-01

    A new global synthesis and biomization of long (> 40 kyr) pollen-data records is presented and used with simulations from the HadCM3 and FAMOUS climate models and the BIOME4 vegetation model to analyse the dynamics of the global terrestrial biosphere and carbon storage over the last glacial-interglacial cycle. Simulated biome distributions using BIOME4 driven by HadCM3 and FAMOUS at the global scale over time generally agree well with those inferred from pollen data. Global average areas of grassland and dry shrubland, desert, and tundra biomes show large-scale increases during the Last Glacial Maximum, between ca. 64 and 74 ka BP and cool substages of Marine Isotope Stage 5, at the expense of the tropical forest, warm-temperate forest, and temperate forest biomes. These changes are reflected in BIOME4 simulations of global net primary productivity, showing good agreement between the two models. Such changes are likely to affect terrestrial carbon storage, which in turn influences the stable carbon isotopic composition of seawater as terrestrial carbon is depleted in 13C.

  18. AGN flickering on 10-100 kyr timescales

    NASA Astrophysics Data System (ADS)

    Sartori, Lia F.; Schawinski, Kevin; Kill, Bill; Maksym, Peter; Koss, Michael; Argo, Megan; Urry, Meg; Wong, Ivy; Lintott, Chris

    2016-08-01

    The study of AGN variability on timescales of 10^4-10^5 years is important in order to understand the BH - host galaxy interaction and coevolution. The discovery of "Hanny's Voorwerp" (HV), an extended emission line region associated with the nearby galaxy IC 2497, provided us with a laboratory to study AGN variability over such timescales. HV was illuminated by a strong quasar in IC 2497, but this quasar significantly shut down in the last 200 kyrs. Thanks to its recent shutdown we can now explore the host galaxy unimpeded by the presence of a quasar dominating the observations, while the Voorwerp preserves the echoes of its past activity. Recent studies on the optical properties of hard X-ray selected AGN suggest that AGN may flicker on and off hundreds or thousands times with each burst lasting ~10^5 yrs. Systems similar to IC 2497 and HV, the so-called Voorwerpjes, allow us to constrain the last stages of the AGN lifecycle. On the other hand, we recently suggested that the switch on phase may be observed in the so-called optically elusive AGN. In this talk I will review both observational evidence and results from simulation work which support this picture, and explain how optically elusive AGN and Voorwerpjes galaxies can help us to understand different phases of the AGN lifecycle. Moreover, I will discuss possible implications for AGN feedback, BH - host galaxy coevolution, and the analogy between AGN and X-ray binaries accretion physics.

  19. Frequency variations of the earth's obliquity and the 100-kyr ice-age cycles

    NASA Technical Reports Server (NTRS)

    Liu, Han-Shou

    1992-01-01

    Changes in the earth's climate are induced by variations in the earth's orbital parameters which modulate the seasonal distribution of solar radiation. Periodicities in the geological climate record with cycles of 100, 41, and 23 kyr have been linked with changes in obliquity, eccentricity, and precession of the equinoxes. The effect of variations of eccentricity during a 100 kyr period is weak relative to the signals from obliquity and precession variations and it may therefore be expected that the 100 kyr signal in the climate record would be of low intensity. However, this signal dominates the climate record and internal nonlinear processes within the climate system have previously been proposed to account for this fact. The author shows that variations in the frequency of the obliquity cycle can give rise to strong 100-kyr forcing of climate.

  20. High temporal Resolution Fire History in Eastern Africa: the Last 16 kyr cal. BP

    NASA Astrophysics Data System (ADS)

    Vanniere, B.; Carcaillet, C.; Garcin, Y.; Vullien, A.; Williamson, D.

    2004-12-01

    Charcoal series, based on a high temporal resolution analysis, at Lake Massoko (9°20' S, 33° 45' E, 770 a.s.l., SW Tanzania) reveals numerous changes of fire regime over the last 16 kyr cal BP. Data are based on the tallying of charcoal from 700 continuous 1 cm thick samples along a 7m long sequence. The structure of charcoal particles is well preserved with an length:width ratio superior to 5; this appears to testify to the local provenance of the material studied and to the rapid transport of particles to the lake. The majority of particles belongs to herbaceous cuticles produced by savanna or bush fires. Time control is supported by 14 radiocarbon dates. Mean time resolution per sample of 17 yr provides the first long detailed biomass burning record in Africa. This record evidences frequent fires events during the last 16 kyr, indicating that fire is a key component of east African ecosystems since, at least, the last glacial stage up to present. From 16 to 12 kyr cal BP, the charcoal influx into the lake is low except during two specific sequences, between 13.5-12.5 kyr cal BP and 14.5-14 kyr cal BP. These may correspond to more arid or more biomass-available phases. Around 10 kyr cal BP, at the early Holocene a greater influx of charcoal is recorded in the lake, probably as a result of a high fire regime likely triggered by severe droughts. Between 8.3 and 1.7 kyr cal BP, the charcoal influx displays a cyclic fire history of ca. 500 yr. Low fire regime, between 3.5-2.5, 5.5-5 and 7.5-7 kyr cal BP, correspond to wetter periods. About 12 sequences of fire increase and decrease are highlighted, which appears to support a high climatic variability during the middle-Holocene. After 1.7 kyr BP, there is a long lasting increase of charcoal influx into the lake, as observed by black carbon analysis (Thevenon et al., 2003). This particular period, without analog since 16 kyr cal BP, is consistent with the development of Iron Age settlements in the region, slash

  1. An 84-kyr paleomagnetic record from the sediments of Lake Baikal, Siberia

    USGS Publications Warehouse

    Peck, J.A.; King, J.W.; Colman, Steven M.; Kravchinsky, V.A.

    1996-01-01

    We have conducted a paleomagnetic study of sediment cores obtained from the Selenga prodelta region of Lake Baikal, Russia. This record, which spans approximately the last 84 kyr, contributes to a better understanding of the nature of geomagnetic field behavior in Siberia and is a useful correlation and dating tool. We demonstrate that the Lake Baikal sediments are recording variations in the geomagnetic field. The directional record displays secular variation behavior with a geomagnetic excursion at 20 ka and additional excursions appearing as large-amplitude secular variation at 41, 61, and 67 ka. Smoothing of the geomagnetic excursion behavior occurs in Lake Baikal sediments owing to the intermediate sedimentation rate (13 cm kyr-1). The Lake Baikal relative paleointensity record correlates to absolute paleointensity data for the last 10 kyr and to relative paleointensity records from the Mediterranean Sea and Indian Ocean for the last 84 kyr. This correlation suggests a strong global (i.e., dipole) component to these records and further supports the reliability of sediments as recorders of relative geomagnetic paleointensity. We show that a relative geomagnetic intensity stratigraphy has a potential resolution of 7 kyr by correlating continental and marine records. The geomagnetic intensity stratigraphy helps constrain the age of the difficult to date Lake Baikal sediments.

  2. Observation of 23 Supernovae That Exploded <300 pc from Earth during the past 300 kyr

    NASA Astrophysics Data System (ADS)

    Firestone, R. B.

    2014-07-01

    Four supernovae (SNe), exploding <=300 pc from Earth, were recorded 44, 37, 32, and 22 kyr ago in the radiocarbon (14C) record during the past 50 kyr. Each SN left a nearly identical signature in the record, beginning with an initial sudden increase in atmospheric radiocarbon, when the SN exploded, followed by a hiatus of 1500 yr, and concluding with a sustained 2000 yr increase in global radiocarbon due to γ-rays produced by diffusive shock in the SN remnant (SNR). For the past 18 kyr excess radiocarbon has decayed with the 14C half-life. SN22kyrBP, is identified as the Vela SN that exploded 250 ± 30 pc from Earth. These SN are confirmed in the 10Be, 26Al, 36Cl, and NO_3^- geologic records. The rate of near-Earth SNe is consistent with the observed rate of historical SNe giving a galactic rate of 14 ± 3 kyr-1 assuming the Chandra Galactic Catalog SNR distribution. The Earth has been used as a calorimeter to determine that ≈2 × 1049 erg were released as γ-rays at the time of each SN explosion and ≈1050 erg in γ-rays following each SN. The background rate of 14C production by cosmic rays has been determined as 1.61 atoms cm-2 s-1. Approximately 1/3 of the cosmic ray energy produced by diffusive shock in the SNR was observed to be emitted as high-energy γ-rays. Analysis of the 10Be/9Be ratio in marine sediment identified 19 additional near-Earth SNe that exploded 50-300 kyr ago. Comparison of the radiocarbon record with global temperature variations indicated that each SN explosion is correlated with a concurrent global warming of ≈3°C-4°C.

  3. Mesozoic cyclostratigraphy, the 405-kyr orbital eccentricity metronome, and the Astronomical Time Scale (Invited)

    NASA Astrophysics Data System (ADS)

    Hinnov, L.; Ogg, J. G.

    2009-12-01

    Mesozoic cyclostratigraphy from around the world is being assessed to construct a continuous Astronomical Time Scale (ATS) based on Earth’s cyclic orbital parameters. The recognition of a prevalent sedimentary cycling with a ~400-kyr period associated with forcing by the stable 405-kyr orbital eccentricity variation is an important development. Numerous formations spanning 10 to 20 myr (and longer) intervals in the Cretaceous, Jurassic and Triassic clearly express this dominant cycle and provide a robust basis for 405-kyr-scale calibration of the ATS. This 405-kyr metronome will enable extension of the well-defined Cenozoic ATS for scaling of the past quarter-billion years of Earth history. This astronomical calibration has a resolution comparable to the 1% to 0.1% precision for radioisotope dating of Mesozoic ash beds, with the added benefit of providing continuous stratigraphic coverage between dated beds. Extended portions of the Mesozoic ATS have already provided new insights into long-standing geologic problems of seafloor spreading, tectonics, eustasy, and paleoclimate change. Ongoing work is focused on closing gaps in coverage and on collecting duplicate cyclostratigraphic records for the entire Mesozoic Era.

  4. A 640 kyr geomagnetic and palaeoclimatic record from Lake Baikal sediments

    NASA Astrophysics Data System (ADS)

    Kravchinsky, Vadim A.; Evans, Michael E.; Peck, John A.; Sakai, Hideo; Krainov, Mikhail A.; King, John W.; Kuzmin, Mikhail I.

    2007-07-01

    Magnetic remanence vectors for 1737 samples from two ~100 m cores of Lake Baikal sediments are reported along with complete magnetic susceptibility profiles obtained from a pass-through system. Chronological control is established by means of two independent correlations; first, by matching susceptibility variations to the oceanic oxygen isotope record and second, by matching the relative palaeointensity variations to the SINT-800 global reference curve. These both imply an average deposition rate of 15 cm kyr-1 and a basal age of ~640 ka. Spectral analysis reveals the presence of Milankovitch signals at ~100 kyr (eccentricity), ~41 kyr (obliquity) and ~23 and ~19 kyr (precession). Stable remanence vectors are almost all of normal polarity. The few exceptions comprise brief intervals of low and/or negative inclinations which probably represent geomagnetic excursions. However, these are far less numerous than the high sedimentation rate would lead one to expect. Furthermore, only four of them can be readily matched to the-still poorly understood-global pattern. These are the Laschamp, the Albuquerque, the Iceland Basin and perhaps the West Eifel excursions which occurred at ~38 000, ~146 000, at 180 000-190 000 and at 480 000-495 000 yr ago, respectively.

  5. Scientific Knowledge Suppresses but Does Not Supplant Earlier Intuitions

    ERIC Educational Resources Information Center

    Shtulman, Andrew; Valcarcel, Joshua

    2012-01-01

    When students learn scientific theories that conflict with their earlier, naive theories, what happens to the earlier theories? Are they overwritten or merely suppressed? We investigated this question by devising and implementing a novel speeded-reasoning task. Adults with many years of science education verified two types of statements as quickly…

  6. A paleomagnetic record of the last 640 kyr from an eastern Mediterranean piston core and a review of geomagnetic excursions in the Brunhes

    NASA Astrophysics Data System (ADS)

    Oda, H.; Dekkers, M. J.; Langereis, C. G.; Lourens, L.; Heslop, D.

    2004-12-01

    Core KC01 (25.93 m long) was taken from a small ridge on the lower slope of the southern Calabrian Ridge (Pisano Plateau, 36deg15.25'N, 17deg44.34'E, 3643m water depth) during cruise MD69 of the French R/V Marion Dufresne in June-July 1991. The sediment consists of hemipelagic sediments with intercalated sapropel and tephra layers. They form an alternation of grey, greenish, olive-coloured, yellowish, white and beige shades. Sapropel layers are black to dark green. Paleomagnetic samples (6.4 cm3 cubes) were taken from the half split cores and measurements of the natural remanent magnetization was conducted at Utrecht University with a DC SQUID magnetometer (2G Enterprises model 740-R). Stepwise alternating field demagnetization was done at 8-11 steps up to 60-80 mT on each sample. Core KC01 (37.04 m long) was taken as a companion core from core KC01B at the same locality, earlier subjected to magnetostratigraphic work (Langereis et al., 1997). Langereis et al. (1997) established an age model based on the matching of (ghost-)sapropels with insolation minima. They applied the 65degN summer insolation calculated from the astronomical solution La90 (Laskar 1990; Laskar et al., 1993) as target curve and included a time lag of 3-kyr - based on the age difference between the radiocarbon dated midpoint of S1 at 8.5 ka and the insolation maximum at 11.5 ka following the method by Lourens et al. (1996). Lourens (2004) modified the astronomical chronology established by Langereis et al. (1997) and investigated the sapropel chronology on KC01B and KC01 based on high resolution colour correlation with ODP Site 964, which is 1 km away, and constructed an improved age model, which gives a better estimate for these two cores. Langereis et al. (1997) reported four excursions (CR0, CR1, CR2, CR3) with ages of 261, 318, 515, and 573 ka based on the chronology of sapropels on Core KC01B. Lourens (2004) revised the chronology of Core KC01B and redated the excursions as 260, 319, 543

  7. δ13Catm and [CO2] measurements in Antarctic ice cores, 160 kyrBP - present

    NASA Astrophysics Data System (ADS)

    Eggleston, Sarah; Schmitt, Jochen; Schneider, Robert; Joos, Fortunat; Fischer, Hubertus

    2014-05-01

    Measurements from Antarctic ice cores allow us to reconstruct atmospheric concentrations of climatically important gases including CO2 over the past 800 kyr. Such measurements show that [CO2] has varied in parallel with Antarctic temperatures on glacial-interglacial timescales. Knowledge of the variations of the stable carbon isotope of CO2, δ13Catm, can help us better understand the processes involved in these fluctuations. Here, we present a first complete δ13Catmrecord extending from 160 kyrBP to the present accompanied by δ15N2 measurements during Marine Isotope Stage 3 (MIS 3, 57 - 29 kyrBP). The present record, measured primarily on ice from the EPICA Dome C and Talos Dome ice cores, has an average resolution of 500 yr, focused mainly on the Last Glacial Maximum and termination (180 yr; Schmitt et al., 2012), MIS 3 (660 yr), and Termination II through MIS 5.4 (590 yr; Schneider et al., 2013). Throughout the record, δ13Catm varies between approximately -6.8 and -6.4‰Following a period of relatively constant δ13Catm at the end of MIS 6 (around -6.8), the boundaries of MIS 5 correspond roughly with the beginning and end of a gradual enrichment in this isotope. In comparison, the more recent record depicts three more abrupt excursions to lighter values around 63 - 59, 46, and 17 kyrBP, in each case followed by a slower return (0.4o over the course of 5 - 15 kyr) to more enriched isotopic values. These coincide with Heinrich events 6, 5, and 1, respectively. No direct correlation is observed between the concentration and carbon isotope of CO2 over the last 160 kyr. The data indicate rather that numerous processes, such as uptake and release of atmospheric CO2 by the ocean and land biosphere, perhaps influenced by regions of growing permafrost during MIS 3 and 4, acting on a variety of timescales must be considered in explaining the evolution of δ13Catm on glacial-interglacial timescales. References: Schmitt, J. et al. Science 336, 711-714 (2012) Schneider

  8. Observation of 23 supernovae that exploded <300 pc from Earth during the past 300 kyr

    SciTech Connect

    Firestone, R. B.

    2014-07-01

    Four supernovae (SNe), exploding ≤300 pc from Earth, were recorded 44, 37, 32, and 22 kyr ago in the radiocarbon ({sup 14}C) record during the past 50 kyr. Each SN left a nearly identical signature in the record, beginning with an initial sudden increase in atmospheric radiocarbon, when the SN exploded, followed by a hiatus of 1500 yr, and concluding with a sustained 2000 yr increase in global radiocarbon due to γ-rays produced by diffusive shock in the SN remnant (SNR). For the past 18 kyr excess radiocarbon has decayed with the {sup 14}C half-life. SN22kyrBP, is identified as the Vela SN that exploded 250 ± 30 pc from Earth. These SN are confirmed in the {sup 10}Be, {sup 26}Al, {sup 36}Cl, and NO{sub 3}{sup −} geologic records. The rate of near-Earth SNe is consistent with the observed rate of historical SNe giving a galactic rate of 14 ± 3 kyr{sup –1} assuming the Chandra Galactic Catalog SNR distribution. The Earth has been used as a calorimeter to determine that ≈2 × 10{sup 49} erg were released as γ-rays at the time of each SN explosion and ≈10{sup 50} erg in γ-rays following each SN. The background rate of {sup 14}C production by cosmic rays has been determined as 1.61 atoms cm{sup –2} s{sup –1}. Approximately 1/3 of the cosmic ray energy produced by diffusive shock in the SNR was observed to be emitted as high-energy γ-rays. Analysis of the {sup 10}Be/{sup 9}Be ratio in marine sediment identified 19 additional near-Earth SNe that exploded 50-300 kyr ago. Comparison of the radiocarbon record with global temperature variations indicated that each SN explosion is correlated with a concurrent global warming of ≈3°C-4°C.

  9. Peanut Allergy Treatment: The Earlier in Childhood, the Better

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_160504.html Peanut Allergy Treatment: The Earlier in Childhood, the Better Exposure ... 18, 2016 (HealthDay News) -- A treatment for peanut allergies may work better if it's given to children ...

  10. 2. VIEW, LOOKING SOUTHEAST, SHOWING PIER OF EARLIER SWING BRIDGE ...

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

    2. VIEW, LOOKING SOUTHEAST, SHOWING PIER OF EARLIER SWING BRIDGE - New York, New Haven & Hartford Railroad, Niantic Bridge, Spanning Niantic River between East Lyme & Waterford, Old Lyme, New London County, CT

  11. FDA Facilitates Research on Earlier Stages of Alzheimer's Disease

    MedlinePlus

    ... Updates FDA Facilitates Research on Earlier Stages of Alzheimer's Disease Share Tweet Linkedin Pin it More sharing ... disease.” back to top New Paths for New Alzheimer’s Drugs FDA’s draft guidance aims to encourage research ...

  12. An explanation of the 100 kyr ice age cycle using a simple box model

    NASA Astrophysics Data System (ADS)

    Fowler, A. C.; Rickaby, R. E. M.; Wolff, E. W.

    2012-04-01

    We have developed a conceptually simple box model, similar in philosophy to those of Saltzman, with a view to explaining the 100 kyr period of the most recent ice age signals. Here we explain in detail how and why the various components of the model have been constructed, and we show how the model can be analysed in order to explain its behaviour. We find that the model can explain the 100 kyr cycles as a self-sustaining oscillation, and in addition we can explain the 40 kyr -100 kyr transition, and indeed the post-Eocene cooling, through the variation of weathering rate over geologic time. The central component of the model is an ocean carbon balance, which receives input from the weathering of silicates and carbonates, and loses CaCO3 by the burial of calcareous biomass. It is therefore necessary to also balance calcium and biomass, and thence phosphorus, which we take to be rate limiting. Charge balance is effected through estimates of the conservative ions Na+, Cl-, etc. To this ocean chemistry model we add a simple ice sheet model of the Weertman/Oerlemans/Ghil type, and we allow for rapid deglaciation through an enhanced wastage rate associated with the growth of proglacial lakes like Agassiz. The oscillations which result are due to the interaction of the hysteretic ice sheet growth (allowing for the elevation-accumulation feedback), and a similar hysteresis in the proglacial lake volume. The effect of this on the atmospheric carbon is controlled by the lowering of the carbonate ion which results when the ice sheet meltwater flows into the ocean.

  13. A distal 140 kyr sediment record of Nile discharge and East African monsoon variability

    NASA Astrophysics Data System (ADS)

    Ehrmann, Werner; Schmiedl, Gerhard; Seidel, Martin; Krüger, Stefan; Schulz, Hartmut

    2016-03-01

    Clay mineral assemblages in a sediment core from the distal Nile discharge plume off Israel have been used to reconstruct the late Quaternary Nile sediment discharge into the eastern Mediterranean Sea (EMS). The record spans the last ca. 140 kyr. Smectite abundances indicate the influence of the Blue Nile and the Atbara River that have their headwaters in the volcanic rocks of the Ethiopian Highlands. Kaolinite abundances indicate the influence of wadis, which contribute periodically to the suspension load of the Nile. Due to the geographical position, the climate and the sedimentary framework of the EMS is controlled by two climate systems. The long-term climate regime was governed by the African monsoon that caused major African humid periods (AHPs) with enhanced sediment discharge at 132 to < 126 (AHP 5), 116 to 99 (AHP4), and 89 to 77 ka (AHP3). They lasted much longer than the formation of the related sapropel layers S5 (> 2 kyr), S4 (3.5 kyr), and S3 (5 kyr). During the last glacial period (Marine Isotope Stages (MISs) 4-2), the long-term changes in the monsoonal system were superimposed by millennial-scale changes in an intensified midlatitude glacial system. This climate regime caused short but pronounced drought periods in the Nile catchment, which are linked to Heinrich events and alternate with more humid interstadials. The clay mineral record further implies that feedback mechanisms between vegetation cover and sediment discharge of the Nile are detectable but of minor importance for the sedimentary record in the southeastern Mediterranean Sea during the investigated African humid periods.

  14. Causal links between Nile floods and eastern Mediterranean sapropel formation during the past 125 kyr confirmed by OSL and radiocarbon dating of Blue and White Nile sediments

    NASA Astrophysics Data System (ADS)

    Williams, M. A. J.; Duller, G. A. T.; Williams, F. M.; Woodward, J. C.; Macklin, M. G.; El Tom, O. A. M.; Munro, R. N.; El Hajaz, Y.; Barrows, T. T.

    2015-12-01

    It has long been hypothesised that beds of highly organic mud or sapropels seen in marine sediment cores retrieved from the floor of the eastern Mediterranean accumulated during times of high Nile fluvial discharge. Our recent fieldwork in the valleys of the Blue Nile, the White Nile and the main Nile has for the first time revealed a sequence of extreme flood episodes synchronous with sapropel units S5 (124 kyr), S4 (102 kyr), S3 (81 kyr), S2 (55 kyr) and S1 (13.5-6.5 kyr). There are more weakly defined links with Nile floods and sapropel units S9 (240 kyr), S8 (217 kyr), S7 (195 kyr), S6 (172 kyr), but the dating error terms are too large to allow us to be too definite. During times of extreme floods over the past 125 kyr, wide distributary channels of the Blue Nile flowed across the Gezira alluvial fan in central Sudan and transported a bed load of sand and gravel into the lower White Nile valley. The sands were reworked by wind to form source-bordering dunes, all of which contain heavy minerals of Ethiopian provenance. These source-bordering dunes were active at 115-105 kyr, 60 kyr and 12-7 kyr, all times of extreme Blue Nile floods. The flood and dune sediments were dated using a combination of optically stimulated luminescence (OSL) and radiocarbon analyses. The Quaternary record of Nile floods discussed here shows a precessional signal and reflects episodes of stronger summer monsoon and more northerly seasonal movement of the ITCZ, linked to times of higher insolation in northern tropical latitudes. Progressive aggradation of Holocene Nile channels in northern Sudan has had a profound influence upon human settlement in the last 8 kyr.

  15. Cosmogenic 10Be and Paleoaccumulation Rates at WAIS Divide from 12-19 kyr BP

    NASA Astrophysics Data System (ADS)

    Welten, K. C.; Woodruff, T. E.; Caffee, M. W.

    2012-12-01

    Concentrations of cosmogenic 10Be in polar ice samples are affected by variations in solar activity, geomagnetic field strength, atmospheric mixing and annual snow accumulation rates. We are presently engaged in a study to obtain a continuous 10Be record in a deep ice core (WDC06A) that was drilled at the West Antarctic Ice Sheet (WAIS) Divide, a site with an average snow accumulation rate of ~20 cm weq/yr, similar to the GISP2 site in Greenland. We previously reported 10Be in annual layers in the top 114 m of WDC06A (Woodruff et al. 2011) and 10Be and 36Cl at decadal resolution in the top 560 m (Welten et al. 2009), and are now measuring 10Be in samples from a depth of 1800-2500 m, corresponding to preliminary ages of 10-20 kyr BP. We separated 10Be from ice samples of 300-600 g, following procedures described previously (Finkel and Nishiizumi 1997) and measured 10Be concentrations by accelerator mass spectrometry at PRIME lab. So far, we measured 10Be in 50 ice samples with ages between 12.3-13.9 kyr BP, at a resolution of ~30 yr/sample, and 50 samples from 15.6-19.0 kyr BP at an average resolution of ~70 yr/sample. The 10Be depth profile shows a relative constant value of (28 ± 3) x 10^3 atoms/g for samples younger than 18 kyr BP and a value of (41 ± 3) x 10^3 atoms/g for ice from 18.2-19.0 kyr BP. These values are 50-120% higher than the average concentration of 18.4 x 10^3 atoms/g for WAIS Divide ice samples from the last 420 year of snow accumulation. Although the higher 10Be concentrations in ice from the last glacial stage can be partly attributed to a 10-20% lower geomagnetic field strength (and thus a higher global 10Be production rate), they are mainly due to lower snow accumulation rates during the last glacial stage. After applying corrections for changes in geomagnetic field strength based on the SINT-800 record, we derive average snow accumulation rates of 13-15 cm weq/yr for the age interval of 12-18 kyr BP and of ~10 cm weq/yr for 18.2-19.0 kyr

  16. Prescription stimulant use is associated with earlier onset of psychosis.

    PubMed

    Moran, Lauren V; Masters, Grace A; Pingali, Samira; Cohen, Bruce M; Liebson, Elizabeth; Rajarethinam, R P; Ongur, Dost

    2015-12-01

    A childhood history of attention deficit hyperactivity disorder (ADHD) is common in psychotic disorders, yet prescription stimulants may interact adversely with the physiology of these disorders. Specifically, exposure to stimulants leads to long-term increases in dopamine release. We therefore hypothesized that individuals with psychotic disorders previously exposed to prescription stimulants will have an earlier onset of psychosis. Age of onset of psychosis (AOP) was compared in individuals with and without prior exposure to prescription stimulants while controlling for potential confounding factors. In a sample of 205 patients recruited from an inpatient psychiatric unit, 40% (n = 82) reported use of stimulants prior to the onset of psychosis. Most participants were prescribed stimulants during childhood or adolescence for a diagnosis of ADHD. AOP was significantly earlier in those exposed to stimulants (20.5 vs. 24.6 years stimulants vs. no stimulants, p < 0.001). After controlling for gender, IQ, educational attainment, lifetime history of a cannabis use disorder or other drugs of abuse, and family history of a first-degree relative with psychosis, the association between stimulant exposure and earlier AOP remained significant. There was a significant gender × stimulant interaction with a greater reduction in AOP for females, whereas the smaller effect of stimulant use on AOP in males did not reach statistical significance. In conclusion, individuals with psychotic disorders exposed to prescription stimulants had an earlier onset of psychosis, and this relationship did not appear to be mediated by IQ or cannabis. PMID:26522870

  17. Research promises earlier warning for grapevine canker diseases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When it comes to detecting and treating vineyards for grapevine canker diseases (also called trunk diseases), like Botryosphaeria dieback (Bot canker), Esca, Eutypa dieback and Phomopsis dieback, the earlier the better, says plant pathologist Kendra Baumgartner, with the USDA’s Agricultural Research...

  18. Century-scale climate-driven vegetation and environmental dynamics in southern Siberia during the last 47 kyr

    NASA Astrophysics Data System (ADS)

    Tarasov, Pavel; Bezrukova, Elena; Solovieva, Nadia; Riedel, Frank

    2010-05-01

    Radiocarbon-dated pollen and diatom records from Lake Kotokel in southern Siberia are used to reconstruct the environmental history of the area since ~47 kyr BP. Pollen data and reconstructed biome scores suggest predominance of a tundra-steppe vegetation and variable woody cover (5-20%) between ~47-30 kyr BP, indicating generally a harsh and unstable climate during this interval, conventionally regarded as the MIS3 interstadial. The short-term climate amelioration episodes in the glacial part of the records are marked by the peaks in taiga and corresponding minima in steppe biome scores and appear synchronously with the hemispheric temperature and precipitation changes recorded in the Greenland ice cores and Chinese stalagmites. The interval ~30-24 kyr BP was probably the driest and coldest of the whole record, as indicated by highest scores for steppe biome, woody coverage <5%, absence of diatoms and reduced size of the lake. A slight amelioration of the regional climate ~24-22 kyr BP was followed by a shorter than the previous and less pronounced deterioration phase. After 14.7 kyr BP the climate became warmer and wetter than ever during ~47-14.7 kyr BP, resulting in the deepening of the lake and increase in the woody coverage to 20-30% ~14.5-14 kyr and ~13.3-12.8 kyr BP. These two intervals correspond to the Meiendorf and Allerød interstadials, which until now were interpreted as part of the undifferentiated Bølling/Allerød interstadial complex in the Lake Baikal region. The increase in tundra biome scores and pronounced change in the diatom composition allow (for the first time) the unambiguous identification of the Younger Dryas (YD) in the region ~12.7-11.65 kyr BP, suggesting the synchronous onset of the YD and the Holocene interglacial across Eurasia. The maximal spread of the taiga communities in the region is associated with a warmer and wetter climate than the present prior to ~7 kyr BP. This was followed by a wide spread of Scots pine, indicating

  19. The 6 and 130 kyr BP climates as simulated by an updated version of LOVECLIM1.2

    NASA Astrophysics Data System (ADS)

    Loutre, M.-F.; Fichefet, T.; Goosse, H.; Barriat, P.-Y.; Sallaz-Damaz, Y.; Timmermann, A.; Laurian, A.; Barthélemy, A.

    2012-04-01

    New modules are included in LOVECLIM1.2 (Goosse et al, 2010). First, a modified atmospheric balance equation is implemented. It links the computed changes of the atmospheric streamfunction with the geopotential height at each level (ABEL) by representing the effect of divergent winds on the streamfunction (Timmermann, 2011, personnal communication). Second, a parameterisation of katabatic winds is implemented (KATA). Their impact on the Antarctic sea ice is represented through constant corrections applied to the ice transport in the vicinity of the coast (Barthelemy, 2011). Third, an empirical diagnostic cloud scheme, based on the ERA-40 reanalysis data (Uppala et al., 2005), is introduced in LOVECLIM to address cloud feedbacks (Timmermann, 2011, personnal communication) (CLOU). This modified version of LOVECLIM has been tested under pre-industrial, mid-holocene (6 kyr BP) and last interglacial (130 kyr BP) forcing conditions. Two setups were used and compared to LOVECLIM1.2, i.e. AK01, which includes both ABEL and KATA, and AK02, which also includes CLOU. First, AK01 and AK02 simulated climates are compared to the LOVECLIM1.2 one. Both AK01 and AK02 induce a global annual mean cooling of 0.4C for the pre-industrial period, and of 0.3C at 6 kyr and at 130 kyr BP. In summer (JJAS) the cooling is mostly located over continents and tropical areas. There is also a strong cooling off Antarctica in the Weddell Sea, while the Pacific sector of the Southern Ocean experiences a warming. In both cases (AK01 and AK02), summer precipitation is reduced in equatorial regions (mostly over the Indian and Pacific Oceans) and enhanced in tropical regions, especially over North Africa. Second, the simulated Holocene (6 kyr BP) and pre-industrial (present) climate are compared. On global annual mean, the surface temperature is 0.3C higher at 6 kyr BP than at present. The warming in summer (JJAS) is the largest in the high northern latitudes, especially over Greenland and North America

  20. Earlier green-up and spring warming amplification over Europe

    NASA Astrophysics Data System (ADS)

    Ma, Shaoxiu; Pitman, Andy J.; Lorenz, Ruth; Kala, Jatin; Srbinovsky, Jhan

    2016-03-01

    The onset of green-up of plants has advanced in response to climate change. This advance has the potential to affect heat waves via biogeochemical and biophysical processes. Here a climate model was used to investigate only the biophysical feedbacks of earlier green-up on climate as the biogeochemical feedbacks have been well addressed. Earlier green-up by 5 to 30 days amplifies spring warming in Europe, especially heat waves, but makes few differences to heat waves in summer. This spring warming is most noticeable within 30 days of advanced green-up and is associated with a decrease in low- and middle-layer clouds and associated increases of downward short wave and net radiation. We find negligible differences in the Southern Hemisphere and low latitudes of the Northern Hemisphere. Our results provide an estimate of the level of skill necessary in phenology models to avoid introducing biases in climate simulations.

  1. The Liang Bua faunal remains: a 95k.yr. sequence from Flores, East Indonesia.

    PubMed

    van den Bergh, G D; Meijer, H J M; Due Awe, Rokhus; Morwood, M J; Szabó, K; van den Hoek Ostende, L W; Sutikna, T; Saptomo, E W; Piper, P J; Dobney, K M

    2009-11-01

    Excavations at Liang Bua, a limestone cave on the island of Flores, East Indonesia, have yielded a well-dated archaeological and faunal sequence spanning the last 95k.yr., major climatic fluctuations, and two human species -H. floresiensis from 95 to 17k.yr.(1), and modern humans from 11k.yr. to the present. The faunal assemblage comprises well-preserved mammal, bird, reptile and mollusc remains, including examples of island gigantism in small mammals and the dwarfing of large taxa. Together with evidence from Early-Middle Pleistocene sites in the Soa Basin, it confirms the long-term isolation, impoverishment, and phylogenetic continuity of the Flores faunal community. The accumulation of Stegodon and Komodo dragon remains at the site in the Pleistocene is attributed to Homo floresiensis, while predatory birds, including an extinct species of owl, were largely responsible for the accumulation of the small vertebrates. The disappearance from the sequence of the two large-bodied, endemic mammals, Stegodon florensis insularis and Homo floresiensis, was associated with a volcanic eruption at 17 ka and precedes the earliest evidence for modern humans, who initiated use of mollusc and shell working, and began to introduce a range of exotic animals to the island. Faunal introductions during the Holocene included the Sulawesi warty pig (Sus celebensis) at about 7ka, followed by the Eurasian pig (Sus scrofa), Long-tailed macaque, Javanese porcupine, and Masked palm civet at about 4ka, and cattle, deer, and horse - possibly by the Portuguese within historic times. The Holocene sequence at the site also documents local faunal extinctions - a result of accelerating human population growth, habitat loss, and over-exploitation.

  2. Constraint on the penultimate glacial maximum Northern Hemisphere ice topography (≈140 kyrs BP)

    NASA Astrophysics Data System (ADS)

    Colleoni, Florence; Wekerle, Claudia; Näslund, Jens-Ove; Brandefelt, Jenny; Masina, Simona

    2016-04-01

    The penultimate glacial maximum (PGM, ≈140 kyrs BP), is known to be the most extensive glaciation on record that occurred during the last 400 kyrs over Eurasia. We used a coupled Atmosphere-Ocean-Sea-Ice-Land model to simulate the climate of the PGM accounting for a reconstruction of the large PGM Eurasian ice sheet. Due to uncertainties in the PGM Laurentide ice-sheet topography, two simulations with different ice-sheet topographies over North America (large as for the Last Glacial Maximum, LGM and small as for 13 kyrs BP) are performed. Results show that the simulated PGM glacial maximum climates are of comparable magnitude with previous simulations of the LGM in both cases. Assuming a small Laurentide ice-sheet instead of the LGM one in our PGM simulations results in a shift in the planetary waves. This causes an increase in storm track activity over the North Atlantic as well as higher temperatures and precipitation rates over North America, North Atlantic and over the Eurasian ice sheet. In addition, it induces a negative temperature anomaly over East Siberia yielding a thick snow cover, which seems to be in agreement with data from recent Arctic campaigns suggesting that an ice cap developed over Beringia during the PGM. All together, the changes in large-scale circulation and regional climate simulated using a small Laurentide ice sheet match the proxies well. Based on our findings, we suggest that the Laurentide ice sheet might have been smaller during the PGM than during the LGM, in turn also implying a larger Eurasian ice sheet than during the LGM, which is supported by various geological evidence of the PGM.

  3. Glacial ocean and continental climate variability off southernmost Chile during the past 60 kyr

    NASA Astrophysics Data System (ADS)

    Lamy, F.; Caniupan, M.; Arz, H. W.; Hebbeln, D.; Kaiser, J.; Kilian, R.; Kissel, C.; Lange, C.; Mollenhauer, G.; Ninnemann, U.

    2009-04-01

    We present paleoceanographic and continental paleoclimate data from sediment core MD07-3128 recovered during IMAGES XV-MD159-PACHIDERME cruise off southernmost Chile. The coring site is located at ~53°S at the continental slope (~1000 m water depth) off the Pacific entrance of the Strait of Magellan. Based on the preliminary stratigraphy (14C and paleomagnetic evidence), the Holocene sequence is very condensed and largely consists of foraminifera sand, whereas enhanced terrestrial sediment input provides high time-resolution during the last glacial back to ca. 65 kyr BP. The alkenone SST record reveals a very strong warming of ca. 8˚C over the last termination and millennial-sale variability in the order of 2-4˚C in the glacial (MIS 2-4). The timing and structure of the termination and some of the millennial-scale fluctuations in the glacial are very similar to those observed in the well-dated SST record from the Chilean margin ODP Site 1233 (41°S) and in the temperature reconstructions from Antarctic ice-cores. There are however important differences in the new southernmost Chilean margin record, e.g. regarding a long-term warming trend over the MIS 3 followed by a cooling towards the LGM. Opal/CaCO3 ratios are generally higher and alkenone concentrations lower during millennial-scale cold intervals suggesting SST-related shifts in the calcareous and siliceous plankton communities. The cold period between ~25 to ~19 kyr BP is accompanied by a significant increase in ice rafted debris and alkenone C37:4 content in particular at ~21, ~20 and ~18 kyr BP that correlate with reduced iron contents (most likely due to Quarz-rich IRD). These changes may be related with glacier advances documented in the Strait of Magellan region or wind-driven changes in the advection of ice-bergs to the site.

  4. The Liang Bua faunal remains: a 95k.yr. sequence from Flores, East Indonesia.

    PubMed

    van den Bergh, G D; Meijer, H J M; Due Awe, Rokhus; Morwood, M J; Szabó, K; van den Hoek Ostende, L W; Sutikna, T; Saptomo, E W; Piper, P J; Dobney, K M

    2009-11-01

    Excavations at Liang Bua, a limestone cave on the island of Flores, East Indonesia, have yielded a well-dated archaeological and faunal sequence spanning the last 95k.yr., major climatic fluctuations, and two human species -H. floresiensis from 95 to 17k.yr.(1), and modern humans from 11k.yr. to the present. The faunal assemblage comprises well-preserved mammal, bird, reptile and mollusc remains, including examples of island gigantism in small mammals and the dwarfing of large taxa. Together with evidence from Early-Middle Pleistocene sites in the Soa Basin, it confirms the long-term isolation, impoverishment, and phylogenetic continuity of the Flores faunal community. The accumulation of Stegodon and Komodo dragon remains at the site in the Pleistocene is attributed to Homo floresiensis, while predatory birds, including an extinct species of owl, were largely responsible for the accumulation of the small vertebrates. The disappearance from the sequence of the two large-bodied, endemic mammals, Stegodon florensis insularis and Homo floresiensis, was associated with a volcanic eruption at 17 ka and precedes the earliest evidence for modern humans, who initiated use of mollusc and shell working, and began to introduce a range of exotic animals to the island. Faunal introductions during the Holocene included the Sulawesi warty pig (Sus celebensis) at about 7ka, followed by the Eurasian pig (Sus scrofa), Long-tailed macaque, Javanese porcupine, and Masked palm civet at about 4ka, and cattle, deer, and horse - possibly by the Portuguese within historic times. The Holocene sequence at the site also documents local faunal extinctions - a result of accelerating human population growth, habitat loss, and over-exploitation. PMID:19058833

  5. South Asian monsoon variability during the past 800 kyr revealed by rock magnetic proxies

    NASA Astrophysics Data System (ADS)

    Suganuma, Y.; Yamazaki, T.; Kanamatsu, T.

    2009-05-01

    A rock magnetic investigation was carried out on a sedimentary core taken from the distal portion of the Bengal Fan in order to reconstruct the South Asian monsoon variability during the past 800 kyr. The 10.2 m long piston core MR0503-PC3, recovered at a water depth of 4400 m, consists of clay to silty clay with minor amounts of nannofossils. An age model for the MR0503-PC3 core is established by correlating a relative paleointensity record of the core [Suganuma Y., Yamazaki, T., Kanamatsu, T., Hokanishi, N., 2008. Relative paleointensity record during the last 800 kyr from the equatorial Indian Ocean: implication for relationship between inclination and intensity variations. Geochemistry, Geophysics, Geosystems. 9, Q02011. doi:10.1029/2007GC001723.] to the global paleointensity stack "Sint-800" [Guyodo, Y., Valet, J.P., 1999. Global changes in intensity of the Earth's magnetic field during the past 800 kyr. Nature. 399, 249-252.]. The age model is consistent with the published ages of tephra layers intercalated in the core, and shows continuous sedimentation during the past 800 kyr. Temporal variations in rock magnetic proxies for the magnetic concentration (ARM, IRM, and HIRM), the grain size (Mrs/Ms), and the composition (S -0.3T and S -0.1T) show that the amount of fine-grained magnetite increased during interglacial stages, and then gradually decreased toward the following glacial maxima. This indicates that the supply of fine-grained magnetite probably originated from areal expansion and/or increased pedogenic activity in the Ganges and Brahmaputra Rivers catchment. Increases during warmer periods suggest intensification of the South Asian summer monsoon during interglacial stages. During marine isotope stages (MIS) 15-11, enhancement of fine-grained magnetite and increased hematite and maghemite contributions are observed. These suggest a significant intensification of the South Asian summer monsoon during this period. Our record and other paleoclimatic

  6. Ethical Revision.

    ERIC Educational Resources Information Center

    Jackman, Mary Kathryn

    1994-01-01

    Discusses the dilemma of how to respond to student papers advancing morally repugnant positions. Advocates conceptualizing writing as an ethical act and connecting ethics and revision. Describes briefly how three such student papers were handled. (SR)

  7. Earlier violent television exposure and later drug dependence.

    PubMed

    Brook, David W; Saar, Naomi S; Brook, Judith S

    2008-01-01

    This research examined the longitudinal pathways from earlier violent television exposure to later drug dependence. African American and Puerto Rican adolescents were interviewed during three points in time (n = 463). Exposure to violent television programs in late adolescence predicted exposure to violent television programs in young adulthood, which in turn was related to tobacco/marijuana use, nicotine dependence, and later drug dependence. Some policy and clinical implications suggest regulating the times when violent television programs are broadcast, creating developmentally targeted prevention/treatment programs, and recognizing that watching violent television programs may serve as a cue regarding increased susceptibility to nicotine and drug dependence. PMID:18612881

  8. Glacial lake drainage in Patagonia (13-8 kyr) and response of the adjacent Pacific Ocean

    PubMed Central

    Glasser, Neil F.; Jansson, Krister N.; Duller, Geoffrey A. T.; Singarayer, Joy; Holloway, Max; Harrison, Stephan

    2016-01-01

    Large freshwater lakes formed in North America and Europe during deglaciation following the Last Glacial Maximum. Rapid drainage of these lakes into the Oceans resulted in abrupt perturbations in climate, including the Younger Dryas and 8.2 kyr cooling events. In the mid-latitudes of the Southern Hemisphere major glacial lakes also formed and drained during deglaciation but little is known about the magnitude, organization and timing of these drainage events and their effect on regional climate. We use 16 new single-grain optically stimulated luminescence (OSL) dates to define three stages of rapid glacial lake drainage in the Lago General Carrera/Lago Buenos Aires and Lago Cohrane/Pueyrredón basins of Patagonia and provide the first assessment of the effects of lake drainage on the Pacific Ocean. Lake drainage occurred between 13 and 8 kyr ago and was initially gradual eastward into the Atlantic, then subsequently reorganized westward into the Pacific as new drainage routes opened up during Patagonian Ice Sheet deglaciation. Coupled ocean-atmosphere model experiments using HadCM3 with an imposed freshwater surface “hosing” to simulate glacial lake drainage suggest that a negative salinity anomaly was advected south around Cape Horn, resulting in brief but significant impacts on coastal ocean vertical mixing and regional climate. PMID:26869235

  9. Glacial lake drainage in Patagonia (13-8 kyr) and response of the adjacent Pacific Ocean.

    PubMed

    Glasser, Neil F; Jansson, Krister N; Duller, Geoffrey A T; Singarayer, Joy; Holloway, Max; Harrison, Stephan

    2016-01-01

    Large freshwater lakes formed in North America and Europe during deglaciation following the Last Glacial Maximum. Rapid drainage of these lakes into the Oceans resulted in abrupt perturbations in climate, including the Younger Dryas and 8.2 kyr cooling events. In the mid-latitudes of the Southern Hemisphere major glacial lakes also formed and drained during deglaciation but little is known about the magnitude, organization and timing of these drainage events and their effect on regional climate. We use 16 new single-grain optically stimulated luminescence (OSL) dates to define three stages of rapid glacial lake drainage in the Lago General Carrera/Lago Buenos Aires and Lago Cohrane/Pueyrredón basins of Patagonia and provide the first assessment of the effects of lake drainage on the Pacific Ocean. Lake drainage occurred between 13 and 8 kyr ago and was initially gradual eastward into the Atlantic, then subsequently reorganized westward into the Pacific as new drainage routes opened up during Patagonian Ice Sheet deglaciation. Coupled ocean-atmosphere model experiments using HadCM3 with an imposed freshwater surface "hosing" to simulate glacial lake drainage suggest that a negative salinity anomaly was advected south around Cape Horn, resulting in brief but significant impacts on coastal ocean vertical mixing and regional climate. PMID:26869235

  10. NGRIP temperature reconstruction from 10 to 120 kyr b2k

    NASA Astrophysics Data System (ADS)

    Kindler, P.; Guillevic, M.; Baumgartner, M.; Schwander, J.; Landais, A.; Leuenberger, M.

    2013-07-01

    In order to reconstruct Greenland NGRIP temperature, measurements of δ15N from the beginning of the Holocene to Dansgaard-Oeschger (DO) event 8 have been performed. Together with previously measured and mostly published δ15N data, we are now able to present for the first time a NGRIP temperature reconstruction for the whole last glacial period (beginning of the Holocene back to 120 kyr) including every DO event based on δ15N isotope measurements using a firn densification and heat diffusion model. The detected temperature rises at DO events range from 5 °C (DO 25) up to 16.5 °C (DO 11), ± 3 °C. To bring measured and modelled data into agreement, we had to reduce the accumulation rate given by the ss09sea06bm time scale in some periods significantly, especially during the last glacial maximum (LGM). A comparison between reconstructed temperature and δ18Oice data confirms that the isotopic composition of the stadial was strongly influenced by seasonality. We continuously calculated α (δ18Oice to temperature sensitivity) on a 10 kyr running time window. α variations show an anticorrelation with obliquity, in agreement with a simple Rayleigh distillation model, and moreover seem to be influenced by Northern Hemisphere ice sheet volume.

  11. Toward a continuous 405-kyr-calibrated Astronomical Time Scale for the Mesozoic Era

    NASA Astrophysics Data System (ADS)

    Hinnov, Linda; Ogg, James; Huang, Chunju

    2010-05-01

    Mesozoic cyclostratigraphy is being assembled into a continuous Astronomical Time Scale (ATS) tied to the Earth's cyclic orbital parameters. Recognition of a nearly ubiquitous, dominant ~400-kyr cycling in formations throughout the era has been particularly striking. Composite formations spanning contiguous intervals up to 50 myr clearly express these long-eccentricity cycles, and in some cases, this cycling is defined by third- or fourth-order sea-level sequences. This frequency is associated with the 405-kyr orbital eccentricity cycle, which provides a basic metronome and enables the extension of the well-defined Cenozoic ATS to scale the majority of the Mesozoic Era. This astronomical calibration has a resolution comparable to the 1% to 0.1% precision for radioisotope dating of Mesozoic ash beds, but with the added benefit of providing continuous stratigraphic coverage between dated beds. Extended portions of the Mesozoic ATS provide solutions to long-standing geologic problems of tectonics, eustasy, paleoclimate change, and rates of seafloor spreading.

  12. Synchronous changes in atmospheric CH4 and Greenland climate between 40 and 8 kyr BP

    NASA Astrophysics Data System (ADS)

    Chappellaz, J.; Bluniert, T.; Raynaud, D.; Barnola, J. M.; Schwander, J.; Stauffert, B.

    1993-12-01

    ICE-CORE reconstructions of atmospheric methane concentrations for the past 220 kyr have revealed large variations associated with different climatic periods1-4. But the phase relationship between climate and methane has been uncertain because of dating uncertainties and the coarse sampling interval of available methane records. Here we present a high-resolution record of atmospheric methane from 40 to 8 kyr ago from the GRIP ice core in Green-land. Our improved resolution and dating allow us to conclude that the large changes in atmospheric methane concentration during the last deglaciation were in phase (+/-200 years) with the variations in Greenland climate. Our results confirm the previous observation3 that methane increased to Holocene levels when much of the Northern wetlands was still ice-covered, lending support to the suggestion3 that low-latitude wetlands were responsible for the observed changes. We observe oscillations in methane concentration associated with the warm periods (interstadials) that occurred throughout the glacial period5, suggesting that the interstadials were at least hemispheric in their extent. We propose that variations in the hydrological cycle at low latitudes may be responsible for the variations in both methane and Greenland temperature during the interstadials.

  13. 100 Kyr Old Desert of Western India: Morhodynamics and Environmental Significance

    NASA Astrophysics Data System (ADS)

    Bhatt, N.

    2012-04-01

    The Late Quaternary oscillations in sea levels and resultant changes in the coastal environment have remained a popular aspect of study amongst the earthscientists and archaeologists. The Saurashtra peninsula of the western India that lies on the southwestern side of the Thar Desert, has archived a fascinating record of such environmental changes since last interglacial (~120kyr) in the form of a fossil desert exhibiting various aeolian land forms constituted by the sand largely derived from the coastal areas due to an oscillatory sea level change. A variety of dunes viz., coastal transverse, parabolic, longitudinal, barchans, climbing and falling dunes along with valley fills and sand sheets have been mapped. Being biogenic calcium carbonate rich, the sands have been lithified under the influence of an increase in moisture and thus the dune and bed forms are preserved in its best shape. The intense aeolian activities are also evident in the form of desert varnish on rocky outcrops. The sequence comprises smaller climate perturbations in the form of stabilization, erosion and karstification of older dunes and deposition of fluvial sediments in between. The paper deals with the mode of occurrence, response of sediments to wind dynamics and palaeo topography, internal structures, later modifications of sediments and significance of the geochronologically constrained aeolianites in understanding of environmental changes since 100kyr in the region.

  14. Glacial lake drainage in Patagonia (13-8 kyr) and response of the adjacent Pacific Ocean.

    PubMed

    Glasser, Neil F; Jansson, Krister N; Duller, Geoffrey A T; Singarayer, Joy; Holloway, Max; Harrison, Stephan

    2016-02-12

    Large freshwater lakes formed in North America and Europe during deglaciation following the Last Glacial Maximum. Rapid drainage of these lakes into the Oceans resulted in abrupt perturbations in climate, including the Younger Dryas and 8.2 kyr cooling events. In the mid-latitudes of the Southern Hemisphere major glacial lakes also formed and drained during deglaciation but little is known about the magnitude, organization and timing of these drainage events and their effect on regional climate. We use 16 new single-grain optically stimulated luminescence (OSL) dates to define three stages of rapid glacial lake drainage in the Lago General Carrera/Lago Buenos Aires and Lago Cohrane/Pueyrredón basins of Patagonia and provide the first assessment of the effects of lake drainage on the Pacific Ocean. Lake drainage occurred between 13 and 8 kyr ago and was initially gradual eastward into the Atlantic, then subsequently reorganized westward into the Pacific as new drainage routes opened up during Patagonian Ice Sheet deglaciation. Coupled ocean-atmosphere model experiments using HadCM3 with an imposed freshwater surface "hosing" to simulate glacial lake drainage suggest that a negative salinity anomaly was advected south around Cape Horn, resulting in brief but significant impacts on coastal ocean vertical mixing and regional climate.

  15. Changes toward earlier streamflow timing across western North America

    USGS Publications Warehouse

    Stewart, I.T.; Cayan, D.R.; Dettinger, M.D.

    2005-01-01

    The highly variable timing of streamflow in snowmelt-dominated basins across western North America is an important consequence, and indicator, of climate fluctuations. Changes in the timing of snowmelt-derived streamflow from 1948 to 2002 were investigated in a network of 302 western North America gauges by examining the center of mass for flow, spring pulse onset dates, and seasonal fractional flows through trend and principal component analyses. Statistical analysis of the streamflow timing measures with Pacific climate indicators identified local and key large-scale processes that govern the regionally coherent parts of the changes and their relative importance. Widespread and regionally coherent trends toward earlier onsets of springtime snowmelt and streamflow have taken place across most of western North America, affecting an area that is much larger than previously recognized. These timing changes have resulted in increasing fractions of annual flow occurring earlier in the water year by 1-4 weeks. The immediate (or proximal) forcings for the spatially coherent parts of the year-to-year fluctuations and longer-term trends of streamflow timing have been higher winter and spring temperatures. Although these temperature changes are partly controlled by the decadal-scale Pacific climate mode [Pacific decadal oscillation (PDO)], a separate and significant part of the variance is associated with a springtime warming trend that spans the PDO phases. ?? 2005 American Meteorological Society.

  16. Earlier vegetation green-up has reduced spring dust storms.

    PubMed

    Fan, Bihang; Guo, Li; Li, Ning; Chen, Jin; Lin, Henry; Zhang, Xiaoyang; Shen, Miaogen; Rao, Yuhan; Wang, Cong; Ma, Lei

    2014-01-01

    The observed decline of spring dust storms in Northeast Asia since the 1950s has been attributed to surface wind stilling. However, spring vegetation growth could also restrain dust storms through accumulating aboveground biomass and increasing surface roughness. To investigate the impacts of vegetation spring growth on dust storms, we examine the relationships between recorded spring dust storm outbreaks and satellite-derived vegetation green-up date in Inner Mongolia, Northern China from 1982 to 2008. We find a significant dampening effect of advanced vegetation growth on spring dust storms (r = 0.49, p = 0.01), with a one-day earlier green-up date corresponding to a decrease in annual spring dust storm outbreaks by 3%. Moreover, the higher correlation (r = 0.55, p < 0.01) between green-up date and dust storm outbreak ratio (the ratio of dust storm outbreaks to times of strong wind events) indicates that such effect is independent of changes in surface wind. Spatially, a negative correlation is detected between areas with advanced green-up dates and regional annual spring dust storms (r = -0.49, p = 0.01). This new insight is valuable for understanding dust storms dynamics under the changing climate. Our findings suggest that dust storms in Inner Mongolia will be further mitigated by the projected earlier vegetation green-up in the warming world.

  17. Earlier vegetation green-up has reduced spring dust storms.

    PubMed

    Fan, Bihang; Guo, Li; Li, Ning; Chen, Jin; Lin, Henry; Zhang, Xiaoyang; Shen, Miaogen; Rao, Yuhan; Wang, Cong; Ma, Lei

    2014-01-01

    The observed decline of spring dust storms in Northeast Asia since the 1950s has been attributed to surface wind stilling. However, spring vegetation growth could also restrain dust storms through accumulating aboveground biomass and increasing surface roughness. To investigate the impacts of vegetation spring growth on dust storms, we examine the relationships between recorded spring dust storm outbreaks and satellite-derived vegetation green-up date in Inner Mongolia, Northern China from 1982 to 2008. We find a significant dampening effect of advanced vegetation growth on spring dust storms (r = 0.49, p = 0.01), with a one-day earlier green-up date corresponding to a decrease in annual spring dust storm outbreaks by 3%. Moreover, the higher correlation (r = 0.55, p < 0.01) between green-up date and dust storm outbreak ratio (the ratio of dust storm outbreaks to times of strong wind events) indicates that such effect is independent of changes in surface wind. Spatially, a negative correlation is detected between areas with advanced green-up dates and regional annual spring dust storms (r = -0.49, p = 0.01). This new insight is valuable for understanding dust storms dynamics under the changing climate. Our findings suggest that dust storms in Inner Mongolia will be further mitigated by the projected earlier vegetation green-up in the warming world. PMID:25343265

  18. Scientific knowledge suppresses but does not supplant earlier intuitions.

    PubMed

    Shtulman, Andrew; Valcarcel, Joshua

    2012-08-01

    When students learn scientific theories that conflict with their earlier, naïve theories, what happens to the earlier theories? Are they overwritten or merely suppressed? We investigated this question by devising and implementing a novel speeded-reasoning task. Adults with many years of science education verified two types of statements as quickly as possible: statements whose truth value was the same across both naïve and scientific theories of a particular phenomenon (e.g., "The moon revolves around the Earth") and statements involving the same conceptual relations but whose truth value differed across those theories (e.g., "The Earth revolves around the sun"). Participants verified the latter significantly more slowly and less accurately than the former across 10 domains of knowledge (astronomy, evolution, fractions, genetics, germs, matter, mechanics, physiology, thermodynamics, and waves), suggesting that naïve theories survive the acquisition of a mutually incompatible scientific theory, coexisting with that theory for many years to follow.

  19. Trend of earlier spring in central Europe continued

    NASA Astrophysics Data System (ADS)

    Ungersböck, Markus; Jurkovic, Anita; Koch, Elisabeth; Lipa, Wolfgang; Scheifinger, Helfried; Zach-Hermann, Susanne

    2013-04-01

    Modern phenology is the study of the timing of recurring biological events in the animal and plant world, the causes of their timing with regard to biotic and abiotic forces, and the interrelation among phases of the same or different species. The relationship between phenology and climate explains the importance of plant phenology for Climate Change studies. Plants require light, water, oxygen mineral nutrients and suitable temperature to grow. In temperate zones the seasonal life cycle of plants is primarily controlled by temperature and day length. Higher spring air temperatures are resulting in an earlier onset of the phenological spring in temperate and cool climate. On the other hand changes in phenology due to climate change do have impact on the climate system itself. Vegetation is a dynamic factor in the earth - climate system and has positive and negative feedback mechanisms to the biogeochemical and biogeophysical fluxes to the atmosphere Since the mid of the 1980s spring springs earlier in Europe and autumn is shifting back to the end of the year resulting in a longer vegetation period. The advancement of spring can be clearly attributed to temperature increase in the months prior to leaf unfolding and flowering, the timing of autumn is more complex and cannot easily be attributed to one or some few parameters. To demonstrate that the observed advancement of spring since the mid of 1980s is pro-longed in 2001 to 2010 and the delay of fall and the lengthening of the growing season is confirmed in the last decade we picked out several indicator plants from the PEP725 database www.pep725.eu. The PEP725 database collects data from different European network operators and thus offers a unique compilation of phenological observations; the database is regularly updated. The data follow the same classification scheme, the so called BBCH coding system so they can be compared. Lilac Syringa vulgaris, birch Betula pendula, beech Fagus and horse chestnut Aesculus

  20. First trimester prenatal diagnosis: earlier is not necessarily better.

    PubMed Central

    Boss, J A

    1994-01-01

    In the past few years considerable attention has been given to a relatively new method of prenatal diagnosis known as chorionic villus sampling (CVS). Because CVS can be performed in the first trimester it is hailed by many as a significant advance over amniocentesis. What has not been as publicized, however, are the disadvantages of CVS and earlier prenatal diagnosis. The emotional costs of CVS in terms of the greater number of both spontaneous and selective abortions following CVS, the use of CVS for sex selection and, because of the greater social acceptability of first trimester abortion, the possibility of increased pressure on women to undergo prenatal diagnosis by health insurance companies, medical professionals and government agencies, all need to be weighed against the advantages of early prenatal diagnosis. PMID:7996559

  1. Reducing Older Driver Motor Vehicle Collisions via Earlier Cataract Surgery

    PubMed Central

    Mennemeyer, Stephen T.; Owsley, Cynthia; McGwin, Gerald

    2013-01-01

    Older adults who undergo cataract extraction have roughly half the rate of motor vehicle collision (MVC) involvement per mile driven compared to cataract patients who do not elect cataract surgery. Currently in the U.S., most insurers do not allow payment for cataract surgery based upon the findings of a vision exam unless accompanied by an individual’s complaint of visual difficulties that seriously interfere with driving or other daily activities and individuals themselves may be slow or reluctant to complain and seek relief. As a consequence, surgery tends to occur after significant vision problems have emerged. We hypothesize that a proactive policy encouraging cataract surgery earlier for a lesser level of complaint would significantly reduce MVCs among older drivers. We used a Monte Carlo model to simulate the MVC experience of the U.S. population from age 60 to 89 under alternative protocols for the timing of cataract surgery which we call “Current Practice” (CP) and “Earlier Surgery” (ES). Our base model finds, from a societal perspective with undiscounted 2010 dollars, that switching to ES from CP reduces by about 21% the average number of MVCs, fatalities, and MVC cost per person. The net effect on total cost – all MVC costs plus cataract surgery expenditures -- is a reduction of about 16%. Quality Adjusted Life Years would increase by about 5%. From the perspective of payers for healthcare, the switch would increase cataract surgery expenditure for ages 65+ by about 8% and for ages 60 to 64 by about 47% but these expenditures are substantially offset after age 65 by reductions in the medical and emergency services component of MVC cost. Similar results occur with discounting at 3% and with various sensitivity analyses. We conclude that a policy of ES would significantly reduce MVCs and their associated consequences. PMID:23369786

  2. Changes in chemical weathering intensity in the Himalayas over the past 30 kyr

    NASA Astrophysics Data System (ADS)

    Dosseto, A.; Vigier, N.

    2010-12-01

    Chemical weathering and climate are tightly coupled and in an era of rapid climate change, it is critical to be able to understand how erosion processes respond to climate variability. A possible approach is to investigate sedimentary records and study how in the past, sediments have recorded the response of catchment erosion to climate variability. In this study, we have measured lithium (Li) isotopes in sediments deposited on river terraces in the upper Ganges (Alaknanda) and Yamuna basins (India) with deposition ages ranging from 0 to 26 kyr. Li isotopes fractionate during chemical weathering and could potentially give us some insights on past variations of weathering intensity. We find that Li isotope composition vary between -1.5 and 2 ‰. Before 14 kyr ago, sediments exhibit negative values followed a sharp increase to positive values between 11 and 14 kyr ago. This increase in could be explained by (i) an increase in average temperature, where a higher temperature of equilibration between water and precipitating clays results in higher Li isotope ratios; (ii) a change in mineralogy, as the type and crystallinity of clays will fact the isotopic composition; or (iii) a decrease in chemical weathering intensity, as Li isotope ratios are believed to decrease in sediments/soils with increasing weathering intensity (Rudnick et al., 2004). Interestingly, this period of shift in Li isotope composition also corresponds to an intensification of monsoon rainfall. If the change in Li isotope compositions is the result of a decrease of chemical weathering intensity, this would imply that despite of more intense rainfall, weathering has been less intense during the Holocene. This could be explained as greater rainfall will generate more erosion and sediments are likely to spend less time in the basin, thus the amount of time available for weathering is reduced. This would imply that chemical weathering is mostly controlled by the erosive power of greater rainfall over

  3. Geomagnetic intensity variations for the past 8 kyr: New archaeointensity results from Eastern China

    NASA Astrophysics Data System (ADS)

    Cai, Shuhui; Tauxe, Lisa; Deng, Chenglong; Pan, Yongxin; Jin, Guiyun; Zheng, Jianming; Xie, Fei; Qin, Huafeng; Zhu, Rixiang

    2014-04-01

    In this study, we have carried out paleointensity experiments on 918 specimens spanning the last ∼7 kyr, including pottery fragments, baked clay and slag, collected from Shandong, Liaoning, Zhejiang and Hebei Provinces in China. Approximately half of the specimens yielded results that passed strict data selection criteria and give high-fidelity paleointensities. The virtual axial dipole moments (VADMs) of our sites range from ∼2×1022 to ∼13×1022 Am. At ∼2250 BCE our results suggest a paleointensity low of ∼2×1022 Am, which increases to a high of ∼13×1022 Am by ∼1300 BCE. This rapid (less than 1000 yrs) six-fold change in the paleointensity may have important implications for the dynamics of core flow at this time. Our data from the last ∼3 kyr are generally in good agreement with the ARCH3k.1 model, but deviate significantly at certain time periods from the CALS3k.4 and CALS10k.1b model, which is likely due to differences in the data used to constrain these models. At ages older than ∼3 ka, where only the CALS10k.1b model is available for comparison, our data deviate significantly from the model. Combining our new results with the published data from China and Japan, we provide greatly improved constraints for the regional model of Eastern Asia. When comparing the variations of geomagnetic field in three global representative areas of Eastern Asia, the Middle East and Southern Europe, a common general trend of sinusoidal variations since ∼8 ka is shown, likely dominated by the dipole component. However, significant disparities are revealed as well, which we attribute to non-dipolar components caused by movement of magnetic flux patches at the core-mantle boundary.

  4. Paleoseismoloigcal evidence of the 1762 and earlier earthquakes off Myanmar

    NASA Astrophysics Data System (ADS)

    Aung, T.; Satake, K.; Okamura, Y.; Shishikura, M.; Swe, W.; Saw, H.; Swe, T.; Tun, S.; Aung, T.

    2007-12-01

    The potential for giant tsunamigenic earthquakes off the west coast of Myanmar, north of the 2004 Sumatra- Andaman earthquake has been debated. Tectonic environments (Cummins, 2007), recent GPS observations (Socquet, 2006) and historical descriptions of geomorphological changes and eyewitness accounts of the 1762 Bengal earthquake seem to support that the earthquake potential exists. As possible evidence of past earthquakes, marine terraces have developed along the Rakhine coast. Our field surveys at the four localities on west and middle Phayonkar islands identified at least three clear steps of marine terraces approximately 1-2 m, ~5 m and ~10 m above present sea level. These steps indicate that sudden sea level change, or coseismic uplift associated with the large earthquakes, occurred in the past. Radiocarbon dating of coral or shell fossils provide ages of the uplift events. Six samples from the lower terrace indicate the most recent uplift occurred between 1585 and 1860 AD. This range includes the 1762 Bengal earthquake. Dates of the middle step, based on four samples, range between 805 and 1220 AD. Four samples on the upper step indicate an uplift event between 1295 and 600 BC. The time interval between the lower and middle step is several hundred years, while that between the middle and upper step is more than 1000 years. The longer time span and the larger elevation difference of the earlier interval may indicate either missing event(s) or variability of earthquake size and recurrence interval.

  5. Earlier North American Monsoon Onset in a Warmer World?

    NASA Astrophysics Data System (ADS)

    Rauscher, S. A.; Seth, A.; Ringler, T.; Rojas, M.; Liebmann, B.

    2009-12-01

    Analysis of twenty-first century projections indicate substantial drying over the American Southwest and the potential for “Dust Bowl” conditions to be the norm by the middle of century. Closer examination of monthly precipitation data from the CMIP3 models indicates that the annual cycle is actually amplified over the North American Monsoon (NAMS) region, with drier conditions during the winter and an increase in monsoon rains during the later part of the rainy season. Importantly, the projected decrease in winter precipitation extends into the spring season, suggesting a delayed onset of the NAMS. Consistent thermodynamic changes, including a decrease in low-level relative humidity and an increase in the vertical gradient of moist static energy, accompany this spring precipitation decrease. Here we examine daily precipitation data from the CMIP3 archive to determine if this reduced spring precipitation represents a true delay in the NAMS onset. We further analyze the hydrological cycle over the NAMS region in several of the CMIP3 models, focusing on changes in net moisture divergence, surface evaporation, and soil moisture in order to fully understand how the hydrological cycle will change in the future based on the CMIP3 simulations, and how these changes may be translated into the timing and intensity of the NAMS. The combination of a delayed NAMS onset and earlier and reduced snowmelt runoff in the western US could substantially change the availability of water resources over the NAMS region.

  6. Earlier speech exposure does not accelerate speech acquisition.

    PubMed

    Peña, Marcela; Werker, Janet F; Dehaene-Lambertz, Ghislaine

    2012-08-15

    Critical periods in language acquisition have been discussed primarily with reference to studies of people who are deaf or bilingual. Here, we provide evidence on the opening of sensitivity to the linguistic environment by studying the response to a change of phoneme at a native and nonnative phonetic boundary in full-term and preterm human infants using event-related potentials. Full-term infants show a decline in their discrimination of nonnative phonetic contrasts between 9 and 12 months of age. Because the womb is a high-frequency filter, many phonemes are strongly degraded in utero. Preterm infants thus benefit from earlier and richer exposure to broadcast speech. We find that preterms do not take advantage of this enriched linguistic environment: the decrease in amplitude of the mismatch response to a nonnative change of phoneme at the end of the first year of life was dependent on maturational age and not on the duration of exposure to broadcast speech. The shaping of phonological representations by the environment is thus strongly constrained by brain maturation factors.

  7. Poorest countries experience earlier anthropogenic emergence of daily temperature extremes

    NASA Astrophysics Data System (ADS)

    Harrington, Luke J.; Frame, David J.; Fischer, Erich M.; Hawkins, Ed; Joshi, Manoj; Jones, Chris D.

    2016-05-01

    Understanding how the emergence of the anthropogenic warming signal from the noise of internal variability translates to changes in extreme event occurrence is of crucial societal importance. By utilising simulations of cumulative carbon dioxide (CO2) emissions and temperature changes from eleven earth system models, we demonstrate that the inherently lower internal variability found at tropical latitudes results in large increases in the frequency of extreme daily temperatures (exceedances of the 99.9th percentile derived from pre-industrial climate simulations) occurring much earlier than for mid-to-high latitude regions. Most of the world’s poorest people live at low latitudes, when considering 2010 GDP-PPP per capita; conversely the wealthiest population quintile disproportionately inhabit more variable mid-latitude climates. Consequently, the fraction of the global population in the lowest socio-economic quintile is exposed to substantially more frequent daily temperature extremes after much lower increases in both mean global warming and cumulative CO2 emissions.

  8. Geomagnetic field variations during the last 400 kyr in the western equatorial Pacific: Paleointensity-inclination correlation revisited

    NASA Astrophysics Data System (ADS)

    Yamazaki, Toshitsugu; Kanamatsu, Toshiya; Mizuno, Sakiko; Hokanishi, Natsumi; Gaffar, Eddy Z.

    2008-10-01

    A paleomagnetic study was conducted on four piston cores newly obtained from the West Caroline Basin in the western equatorial Pacific in order to investigate variations in paleointensity and inclination during the last 400 kyr. An inclination-intensity correlation was previously reported in this region using giant piston cores, but the quality of the paleomagnetic data of the younger end, the last ca. 300 kyr, was needed to be checked because the upper part of the giant piston cores could suffer from perturbation by oversampling. Age control is based on the oxygen-isotope ratios for one core and inter-core correlation using relative paleointensity for other cores. Stacked curves of paleointensity and inclination were constructed from the four cores. It was confirmed that variations on the order of 104 to 105 years occur in inclination as well as paleointensity. A cross-correlation analysis showed that significant in-phase correlation occurs between intensity and inclination for periods longer than about 25 kyr, and power spectra of both paleointensity and inclination variations have peaks at ~100 kyr periods. The regional paleointensity stack with higher resolution than the Sint-800 stack (Guyodo and Valet, 1999) should be useful for paleointensity-assisted chronostratigraphy.

  9. Geomagnetic field variations during the last 400 kyr in the western equatorial Pacific: Paleointensity-inclination correlation revisited

    NASA Astrophysics Data System (ADS)

    Yamazaki, T.; Kanamatsu, T.; Mizuno, S.; Hokanishi, N.; Gaffar, E. Z.

    2008-12-01

    A paleomagnetic study was conducted on four piston cores newly obtained from the West Caroline Basin in the western equatorial Pacific in order to investigate variations in paleointensity and inclination during the last 400 kyr. An inclination-intensity correlation was previously reported in this region using giant piston cores, but the quality of the paleomagnetic data of the younger end, the last ca. 300 kyr, was needed to be checked because the upper part of the giant piston cores could suffer from perturbation by oversampling. Age control is based on the oxygen-isotope ratios for one core and inter-core correlation using relative paleointensity for other cores. The mean inclinations of the four cores show negative inclination anomalies ranging from -5.2 to -11.2 degree. The western equatorial Pacific is documented as a region of a large negative inclination anomalies, and the observed values are comparable to those expected from the time-averaged field (TAF) models [Johnson and Constable, 1997; Hatakeyama and Kono, 2002]. Stacked curves of paleointensity and inclination were constructed from the four cores. It was confirmed that geomagnetic variations on the order of 10 to 100 kyrs occur in inclination as well as paleointensity. A cross-correlation analysis showed that significant in-phase correlation occurs between intensity and inclination for periods longer than about 25 kyr, and power spectra of both paleointensity and inclination variations have peaks at ~100 kyr periods. The regional paleointensity stack with higher resolution than the Sint-800 stack [Guyodo and Valet, 1999] should be useful for paleointensity-assisted chronostratigraphy.

  10. Progress in the reconstruction of Quaternary climate dynamics in the Northwest Pacific: A new modern analogue reference dataset and its application to the 430-kyr pollen record from Lake Biwa

    NASA Astrophysics Data System (ADS)

    Tarasov, Pavel E.; Nakagawa, Takeshi; Demske, Dieter; Österle, Hermann; Igarashi, Yaeko; Kitagawa, Junko; Mokhova, Lyudmila; Bazarova, Valentina; Okuda, Masaaki; Gotanda, Katsuya; Miyoshi, Norio; Fujiki, Toshiyuki; Takemura, Keiji; Yonenobu, Hitoshi; Fleck, Andreas

    2011-09-01

    This study presents a newly compiled dataset of modern pollen and climate data from 798 sites across Japan and the Russian Far East. This comprehensive reference dataset combined with the modern analogue technique (MAT) provides a powerful tool for pollen-based reconstruction of the Quaternary Northwest Pacific climate. Pollen-derived reconstruction of the modern climate at the reference pollen-sampling sites matches well with the estimated modern climate values ( R2 values vary between 0.79 and 0.95, and RMSEP values vary between 5.8 and 9.7% of the modern climatic range for all nine tested variables). The successful testing of the method encourages its application to the fossil pollen records. We used a coarse-resolution pollen record from Lake Biwa to reconstruct glacial-interglacial climate dynamics in central Japan since ~ 438 kyr and compared it to the earlier reconstruction based on a less representative reference dataset. The current and earlier results consistently demonstrate that the coldest glacial intervals experienced pronounced cooling in winter and moderate cooling in summer, supporting the growth of cool mixed forest (COMX) where warm mixed forest (WAMX) predominates today. During the last glacial, maximum (~ 24 kyr BP) mean temperatures of the coldest (MTCO) and warmest (MTWA) month were about - 13 °C (RMSEP = 2.34 °C) and 21 °C (RMSEP = 1.66 °C) respectively, and annual precipitation (PANN) was about 800 mm (RMSEP = 158.06 mm). During the thermal optimums of the interglacial intervals, the temperatures of the coldest and warmest month were above 0 °C and 25 °C respectively, leading to the reconstruction of WAMX and temperate conifer forest (TECO). Although both these vegetation types grow in the southern part of Japan today, WAMX requires warmer space. The presence of WAMX during marine isotope stages (MIS) 11 and 1, and its absence during MIS 9 and MIS 5 contradict the marine isotope and Antarctic ice records, suggesting that the latter

  11. AMS Chronology Reveals Ice Sheet Retreat at 15.5 kyr; Provides North Atlantic Chill and Feedbacks for Abrupt Climate Warming

    NASA Astrophysics Data System (ADS)

    Peteet, D. M.; Beh, M.; Orr, C.; Kurdyla, D.; Guilderson, T. P.

    2009-12-01

    The timing of the southeastern Laurentide ice sheet collapse is critical to understanding ocean-atmosphere-ice dynamics. Yet at present an enigma remains based on conflicting evidence including radiocarbon ages on bulk and identifiable macrofossils in lakes, 10Be cosmogenic dating results, and glacial lake varve sequences. Disparate data sources offer conflicting chronologies concerning when ice began retreating from the Laurentide New York - New Jersey -Pennsylvania Last Glacial Maximum (LGM) position. Our study, an investigation of lake basal clays and silts (0.5-8% organic), finds the deglaciation at 15 kyr. These results are 5-8 kyr later than previous deglaciation chronology (23-20 kyr) based upon bulk radiocarbon dating of lake sediments and extrapolation, 8-12 kyr later than varve chronologies, and 4-8kyr later than 10Be results. Our surprising result is generated by 15 accelerator mass spectrometry 14C dates from tundra/spruce macrofossils in 9 basal lake sediments. These dates indicate pioneer plant colonization from areas south and west as the landscape stabilized, just prior to widespread (Bolling) warming which induced rapid limnic organic sedimentation. While warming began as early as 17kyr as evidenced by terrestrial and marine records south of the ice margin, this cold meltwater lid on the N. Atlantic may have delayed the southern margin retreat to 15 kyr, when ice-free soils/lakes provided positive terrestrial/water vapor feedback for the swift pronounced warming.

  12. Distributive Education: Secondary, Course Outline. Revised 1972.

    ERIC Educational Resources Information Center

    Washington State Coordinating Council for Occupational Education, Olympia.

    The document is a revision of earlier units, updated to include behavioral or performance objectives. Divided into 22 units of instruction, the course outline for distributive education presents suggested length of time for each part of a unit, prerequisites, a description of the part, objectives, sources, outline for the section, activities,…

  13. Circum-Antarctic Nd isotope variability during the last 30 kyrs

    NASA Astrophysics Data System (ADS)

    Struve, T.; van de Flierdt, T.; Hines, S. K.; Burke, A.; Adkins, J. F.; Robinson, L. F.; Crocket, K. C.; Auro, M. E.

    2014-12-01

    The modern Southern Ocean is a key area for the global ocean circulation as wind-driven mixing, upwelling and redistribution of water masses in the Antarctic Circumpolar Current (ACC) all have a significant impact on the properties and flow patterns of global water masses. It has been suggested that the Southern Ocean plays a critical role in oceanographic and climatic changes observed on glacial-interglacial timescales, in particular with respect to carbon sequestration between the deep ocean and the atmosphere. For the purpose of unravelling Southern Ocean water mass composition at intermediate depth during the past 30 kyrs, we here utilise the Nd isotopic composition of the aragonitic skeletons of solitary deep-sea corals. These corals were collected from two locations, the Drake Passage and the area south of Tasmania, and from water depths between 300 and 1750 m. Modern coral specimen were calibrated against nearby seawater. Neodymium was collected from the wash fraction of the anion-exchange column, which represents the first step in preparing samples for precise U-series dating. Subsequent Nd separation utilised a two-stage ion chromatography (RE-spec/cation exchange and Ln-spec resins). Isotopic analyses were performed as NdO+ on a Triton TIMS using a TaF5 activator on W filaments yielding 2σ external reproducibilities of ~20 ppm. (Sub-) millenial scale deep-sea coral neodymium isotope results from the Drake Passage suggest that the modern homogenous ACC neodymium isotopic composition of ɛNd≈ -8 is a very recent feature. During the past 30 kyrs Nd isotope variability on the order of two epsilon units are observed at intermediate water depths as well as repeated changes in water column stratification. We will discuss our new results in the context of other Southern Ocean records, as well as preliminary Nd isotope data from glacial to deglacial deep-sea corals from south of Tasmania in order to constrain the last glacial to deglacial circum-Antarctic Nd

  14. Latitudinal Hydrologic Variability Along the East African Rift, Over the Past 200 Kyr

    NASA Astrophysics Data System (ADS)

    Scholz, C. A.

    2014-12-01

    Within the deep sediments of the large lakes of Africa's Great Rift Valley are continuous environmental records of remarkable antiquity and fidelity. Not only do stratigraphic sections from these basins extend back millions of years, many of the intervals represented contain high-resolution material of decadal resolution or better. East African lake basins remain sparsely sampled however, with only a few long and continuous records available. Our ability to image the lakes using seismic reflection methods greatly exceeds our opportunities for coring and drilling however; assessing stratal relationships observed in the geophysical data permits powerful inferences about past hydrologic changes. With intensive hydrocarbon exploration work underway in East Africa, industry well data can also help constrain and ground truth basin histories. Substantial spatio-temporal hydrologic variability is observed in East African basins over the past 200 kyr. Paleohydrological changes in the late Pleistocene and early Holocene are now well constrained in the northern hemisphere East African topics, with widespread aridity and in some cases lake desiccation observed during Heinrich Event 1. A climate recovery followed in the northern hemisphere East African tropics, with the early Holocene African Humid Period a time of positive water balance across most of the rift valley. The paleohydrology of southern hemisphere tropical East Africa is more equivocal, for instance with negligible draw-down of Lake Malawi at HE1. Whereas these late Pleistocene events represent substantial climate reorganizations, severe droughts during the middle-late Pleistocene (150-65 kyr BP) were far more intense, and produced much more severe drawdowns of Lakes Malawi and Tanganyika. Scientific drill cores, kullenberg cores, and extensive seismic reflection data sets from Lakes Malawi and Tanganyika provide indisputable evidence for lowstands of -500m and -600 m respectively. Climate changes that lowered the

  15. Rock magnetic records of Southeast Asian monsoon variability during the past 800 kyr

    NASA Astrophysics Data System (ADS)

    Suganuma, Y.; Yamazaki, T.; Kanamatsu, T.

    2007-12-01

    Rock magnetic investigations were carried out on a sedimentary core taken from the Ninety-east ridge, the eastern equatorial Indian Ocean in order to reconstruct the South Asia monsoon variability during the past 800 kyr. A 10.2 m long piston core ? MR0503-PC3 was recovered in August 2005 during the R/V Mirai MR0503 cruise. The core site is located in the western flank of the Ninety-east ridge (1×E 13.2'N, 88×E 26.0'E), and water depth is 4400 m. In order to develop an age model for the MR0503-PC3 core, a relative paleointensity record (NRM30mT/IRM30mT) obtained from the core is correlated with the global stack of relative paleointensity records &Sint-? (Guyodo and Valet, 1999). Based on the developed age model, the age of the bottom of the MR0503-PC3 core is ca. 800 ka and an average sedimentation rate is 1.3 cm/kyr. A suite of rock magnetic parameters (Magnetic Susceptibility, IRM, ARM, Mrs/Ms, and S-ratio) was obtained from discrete samples collected from the half-split of the core. Magnetic Susceptibility, IRM, and ARM are used as proxies for the magnetic mineral flux. Mrs/Ms and S-ratio are used as proxies for mean grain size and magnetic mineralogical parameter, respectively. The results show that a magnetic mineral flux increases during warmer periods, whereas the flux decreases during colder periods. On the other hand, magnetic grain size increases during colder periods and decreases during warmer periods. These indicate that a supply of fine-grained magnetite (or maghemite), probably originated to pedogenesis, increases during warmer periods, suggesting intense precipitation related to the South Asian summer monsoon. During MIS 15 to 11, stepwise increases of the magnetic mineral flux accompanied with sudden drops of S-ratios are recognized. The sudden drop of S-ratio is related to intense inputs of coarse-grained hematite and maghemite, probably originated to the chemical weathering of the Himalaya-Tibet plateau. This feature suggests that

  16. Biogenic sedimentation beneath the California Current system for the past 30 kyr and its paleoceanographic significance

    USGS Publications Warehouse

    Gardner, J.V.; Dean, W.E.; Dartnell, P.

    1997-01-01

    A north-south transect of 17 cores was constructed along the eastern boundary of the California Current system from 33?? to 42?? N to investigate the changes in biogenic sedimentation over the past 30 kyr. Percentages and mass accumulation rates of CaCO3, Corg, and biogenic opal were assembled at 500 to 1000 years/sample to provide relatively high resolution. Time-space maps reveal a complex pattern of changes that do not follow a simple glacial-interglacial two-mode model. Biogenic sedimentation shows responses that are sometimes time-transgressive and sometimes coeval, and most of the responses show more consistency within a limited geographic area than any temporal consistency. Reconstructed conditions during late oxygen isotope stage 3 were more like early Holocene conditions than any other time during the last 30 kyr. Coastal upwelling and productivity during oxygen isotope stage 3 were relatively strong along the central California margin but were weak along the northern California margin. Precipitation increased during the last glacial interval in the central California region, and the waters of the southern California margin had relatively low productivity. Productivity on the southern Oregon margin was relatively low at the beginning of the last glacial interval, but by about 20 ka, productivity in this area significantly increased. This change suggests that the center of the divergence of the West Wind Drift shifted south at this time. The end of the last glacial interval was characterized by increased productivity in the southern California margin and increased upwelling along the central California margin but upwelling remained weak along the northern California margin. A sudden (<300 years) decrease in CaCO3, Corg, and biogenic opal occurred at 13 ka. The changes suggest a major reorientation of the atmospheric circulation in the North Pacific and western North America and the establishment of a strong seasonality in the central California region. A

  17. Wet periods in northeastern Brazil over the past 210 kyr linked to distant climate anomalies.

    PubMed

    Wang, Xianfeng; Auler, Augusto S; Edwards, R Lawrence; Cheng, Hai; Cristalli, Patricia S; Smart, Peter L; Richards, David A; Shen, Chuan-Chou

    2004-12-01

    The tropics are the main source of the atmosphere's sensible and latent heat, and water vapour, and are therefore important for reconstructions of past climate. But long, accurately dated records of southern tropical palaeoclimate, which would allow the establishment of climatic connections to distant regions, have not been available. Here we present a 210,000-year (210-kyr) record of wet periods in tropical northeastern Brazil--a region that is currently semi-arid. The record is obtained from speleothems and travertine deposits that are accurately dated using the U/Th method. We find wet periods that are synchronous with periods of weak East Asian summer monsoons, cold periods in Greenland, Heinrich events in the North Atlantic and periods of decreased river runoff to the Cariaco basin. We infer that the wet periods may be explained with a southward displacement of the Intertropical Convergence Zone. This widespread synchroneity of climate anomalies suggests a relatively rapid global reorganization of the ocean-atmosphere system. We conclude that the wet periods probably affected rainforest distribution, as plant fossils show that forest expansion occurred during these intermittent wet intervals, and opened a forest corridor between the Amazonian and Atlantic rainforests. PMID:15592409

  18. Iron fluxes to Talos Dome, Antarctica, over the past 200 kyr

    NASA Astrophysics Data System (ADS)

    Vallelonga, P.; Barbante, C.; Cozzi, G.; Gabrieli, J.; Schüpbach, S.; Spolaor, A.; Turetta, C.

    2013-03-01

    Atmospheric fluxes of iron (Fe) over the past 200 kyr are reported for the coastal Antarctic Talos Dome ice core, based on acid leachable Fe concentrations. Fluxes of Fe to Talos Dome were consistently greater than those at Dome C, with the greatest difference observed during interglacial climates. We observe different Fe flux trends at Dome C and Talos Dome during the deglaciation and early Holocene, attributed to a combination of deglacial activation of dust sources local to Talos Dome and the reorganisation of atmospheric transport pathways with the retreat of the Ross Sea ice shelf. This supports similar findings based on dust particle sizes and fluxes and Rare Earth Element fluxes. We show that Ca and Fe should not be used as quantitative proxies for mineral dust, as they all demonstrate different deglacial trends at Talos Dome and Dome C. Considering that a 20 ppmv decrease in atmospheric CO2 at the coldest part of the last glacial maximum occurs contemporaneously with the period of greatest Fe and dust flux to Antarctica, we confirm that the maximum contribution of aeolian dust deposition to Southern Ocean sequestration of atmospheric CO2 is approximately 20 ppmv.

  19. Iron fluxes to Talos Dome, Antarctica, over the past 200 kyr

    NASA Astrophysics Data System (ADS)

    Vallelonga, P.; Barbante, C.; Cozzi, G.; Gabrieli, J.; Schüpbach, S.; Spolaor, A.; Turetta, C.

    2012-12-01

    Atmospheric fluxes of iron (Fe) over the past 200 kyr are reported for the coastal Antarctic Talos Dome ice core, based on acid leachable Fe concentrations. Fluxes of Fe to Talos Dome were consistently greater than those at Dome C, with the greatest difference observed during interglacial climates. We observe different Fe flux trends at Dome C and Talos Dome during the deglaciation and early Holocene, attributed to a combination of deglacial activation of dust sources local to Talos Dome and reorganization of atmospheric transport pathways with the retreat of the Ross Sea ice shelf. This supports similar findings based on dust particle sizes and fluxes and Rare Earth Element fluxes. We show that Ca and Fe should not be used as quantitative proxies for mineral dust, as they all demonstrate different deglacial trends at Talos Dome and Dome C. Considering that a 20 ppmv decrease in atmospheric CO2 at the coldest part of the last glacial maximum occurs contemporaneously with the period of greatest Fe and dust flux to Antarctica, we conclude that the maximum contribution of aeolian dust deposition to Southern Ocean sequestration of atmospheric CO2 is approximately 20 ppmv.

  20. Strong coherence between solar variability and the monsoon in Oman between 9 and 6 kyr ago.

    PubMed

    Neff, U; Burns, S J; Mangini, A; Mudelsee, M; Fleitmann, D; Matter, A

    2001-05-17

    Variations in the amount of solar radiation reaching the Earth are thought to influence climate, but the extent of this influence on timescales of millennia to decades is unclear. A number of climate records show correlations between solar cycles and climate, but the absolute changes in solar intensity over the range of decades to millennia are small and the influence of solar flux on climate is not well established. The formation of stalagmites in northern Oman has recorded past northward shifts of the intertropical convergence zone, whose northward migration stops near the southern shoreline of Arabia in the present climate. Here we present a high-resolution record of oxygen isotope variations, for the period from 9.6 to 6.1 kyr before present, in a Th-U-dated stalagmite from Oman. The delta18O record from the stalagmite, which serves as a proxy for variations in the tropical circulation and monsoon rainfall, allows us to make a direct comparison of the delta18O record with the Delta14C record from tree rings, which largely reflects changes in solar activity. The excellent correlation between the two records suggests that one of the primary controls on centennial- to decadal-scale changes in tropical rainfall and monsoon intensity during this time are variations in solar radiation.

  1. Temperature reconstruction from 10 to 120 kyr b2k from the NGRIP ice core

    NASA Astrophysics Data System (ADS)

    Kindler, P.; Guillevic, M.; Baumgartner, M.; Schwander, J.; Landais, A.; Leuenberger, M.; Spahni, R.; Capron, E.; Chappellaz, J.

    2014-04-01

    In order to reconstruct the temperature of the North Greenland Ice Core Project (NGRIP) site, new measurements of δ15N have been performed covering the time period from the beginning of the Holocene to Dansgaard-Oeschger (DO) event 8. Together with previously measured and mostly published δ15N data, we present for the first time a NGRIP temperature reconstruction for the whole last glacial period from 10 to 120 kyr b2k (thousand years before 2000 AD) including every DO event based on δ15N isotope measurements combined with a firn densification and heat diffusion model. The detected temperature rises at the onset of DO events range from 5 °C (DO 25) up to 16.5 °C (DO 11) with an uncertainty of ±3 °C. To bring measured and modelled data into agreement, we had to reduce the accumulation rate given by the NGRIP ss09sea06bm timescale in some periods by 30 to 35%, especially during the last glacial maximum. A comparison between reconstructed temperature and δ18Oice data confirms that the isotopic composition of the stadial was strongly influenced by seasonality. We evidence an anticorrelation between the variations of the δ18Oice sensitivity to temperature (referred to as α) and obliquity in agreement with a simple Rayleigh distillation model. Finally, we suggest that α might be influenced by the Northern Hemisphere ice sheet volume.

  2. Wet periods in northeastern Brazil over the past 210 kyr linked to distant climate anomalies.

    PubMed

    Wang, Xianfeng; Auler, Augusto S; Edwards, R Lawrence; Cheng, Hai; Cristalli, Patricia S; Smart, Peter L; Richards, David A; Shen, Chuan-Chou

    2004-12-01

    The tropics are the main source of the atmosphere's sensible and latent heat, and water vapour, and are therefore important for reconstructions of past climate. But long, accurately dated records of southern tropical palaeoclimate, which would allow the establishment of climatic connections to distant regions, have not been available. Here we present a 210,000-year (210-kyr) record of wet periods in tropical northeastern Brazil--a region that is currently semi-arid. The record is obtained from speleothems and travertine deposits that are accurately dated using the U/Th method. We find wet periods that are synchronous with periods of weak East Asian summer monsoons, cold periods in Greenland, Heinrich events in the North Atlantic and periods of decreased river runoff to the Cariaco basin. We infer that the wet periods may be explained with a southward displacement of the Intertropical Convergence Zone. This widespread synchroneity of climate anomalies suggests a relatively rapid global reorganization of the ocean-atmosphere system. We conclude that the wet periods probably affected rainforest distribution, as plant fossils show that forest expansion occurred during these intermittent wet intervals, and opened a forest corridor between the Amazonian and Atlantic rainforests.

  3. U-ages in soils and groundwater evidencing wet periods 400-600kyr ago in southeast Brazil.

    PubMed

    Bonotto, D M; Jiménez-Rueda, J R

    2007-07-01

    (238)U and its radiogenic daughter (234)U have been utilized for dating soil formation and groundwater residence time during the last 1.5 million years, in this case based on the U-dissolution/precipitation occurring during modifications of the oxidation-reduction conditions. In this paper, we report a 400-600kyr proxy of wet periods from sediments occurring in a soil profile developed over rocks outcropping at the Paraná sedimentary basin in Brazil, and from groundwater exploited of Guarani aquifer at the same basin. The approaches indicated successful use of the U-modeled ages for suggesting wet periods exceeding the past 116-210kyr from previous studies.

  4. Droughts in the East Asian summer monsoon margin during the last 6 kyrs: Link to the North Atlantic cooling events

    NASA Astrophysics Data System (ADS)

    Fan, Jiawei; Xiao, Jule; Wen, Ruilin; Zhang, Shengrui; Wang, Xu; Cui, Linlin; Li, He; Xue, Dingshuai; Yamagata, Hideki

    2016-11-01

    Teleconnections to the high latitudes, forcing by the tropical oceans and solar variability have all been suggested as dominant factors in the sub-millennial global climate changes, yet there is little consensus as to the relative importance of these factors for the East Asian summer monsoon (EASM) variability. This study presents the results of high-resolution analyses of Ca and Mg concentrations, Mg/Ca ratio, δ18O and δ13C values of endogenic calcites from a sediment core from Dali Lake in the EASM margin, in order to investigate the sub-millennial EASM variability and its possible driving forces during the last 6 kyrs. Increases in these chemical proxy data were interpreted as drought events in the region due to the intensive evaporation losses overwhelming the water input to the lake. The chemical proxy data in this study combined with multi-proxy indicators including grain size component and total organic carbon concentrations from the same sediment core imply that declines in the EASM intensity may have played a dominant role in triggering the drought events during the last 6 kyrs. The results indicate that the EASM intensity significantly declined at the intervals of 5.8-4.75, 3.2-2.8, 1.65-1.15 and 0.65-0.2 kyrs BP. Large declines in the EASM intensity during the last 6 kyrs correspond in time to occurrences of ice-rafted debris in the North Atlantic, indicating that millennial-to-centennial scale changes in the EASM intensity were mainly controlled by climatic processes occurring in the northern high latitudes. These data imply that persistent global warming may be favorable for the strengthening of the EASM circulation and for the transportation of more rainfall to the semi-arid regions of northern China on sub-millennial scales.

  5. New Benthic δ18o Stacks and Age Models for the Last Glacial Cycle (0-150 kyr ago)

    NASA Astrophysics Data System (ADS)

    Lisiecki, L. E.; Stern, J. V.

    2014-12-01

    The δ18O of formainiferal calcite is a common paleoceanographic proxy, which measures ice volume and deep water temperature change. Foraminiferal δ18O is also often used to create marine sediment core age models by aligning down-core variations in δ18O to a global stack, or average. However, the most commonly used stack, known as "LR04," has an outdated age model, assumes global benthic δ18O synchrony, and is biased to the Atlantic [Lisiecki and Raymo, 2005]. Here we present six regional benthic δ18O stacks of the last glacial cycle (0-150 kyr) that are combined to form a volume-weighted global stack with data from 263 sites. We develop new benthic δ18O age models using regional radiocarbon dates from 0-40 ka and correlations to the GICC05 layer-counted Greenland age model from 40-56 ka [Svensson et al., 2008] and U-Th-dated Chinese speleothems from 56-150 kyr [Wang et al., 2001; Cheng et al., 2009; Barker et al, 2011]. Additional features of the new stacks are diachronous benthic δ18O changes during the last two glacial terminations and explicit age uncertainty estimates throughout. Our new global stack indicates that some portions of the LR04 stack are up to 4 kyr too young. We estimate corrections to the LR04 age model throughout the Pleistocene that imply faster climate responses to orbital forcing than previously estimated.

  6. Terrestrial biosphere changes over the last 120 kyr and their impact on ocean δ 13C

    NASA Astrophysics Data System (ADS)

    Hoogakker, B. A. A.; Smith, R. S.; Singarayer, J. S.; Marchant, R.; Prentice, I. C.; Allen, J. R. M.; Anderson, R. S.; Bhagwat, S. A.; Behling, H.; Borisova, O.; Bush, M.; Correa-Metrio, A.; de Vernal, A.; Finch, J. M.; Fréchette, B.; Lozano-Garcia, S.; Gosling, W. D.; Granoszewski, W.; Grimm, E. C.; Grüger, E.; Hanselman, J.; Harrison, S. P.; Hill, T. R.; Huntley, B.; Jiménez-Moreno, G.; Kershaw, P.; Ledru, M.-P.; Magri, D.; McKenzie, M.; Müller, U.; Nakagawa, T.; Novenko, E.; Penny, D.; Sadori, L.; Scott, L.; Stevenson, J.; Valdes, P. J.; Vandergoes, M.; Velichko, A.; Whitlock, C.; Tzedakis, C.

    2015-03-01

    A new global synthesis and biomization of long (>40 kyr) pollen-data records is presented, and used with simulations from the HadCM3 and FAMOUS climate models to analyse the dynamics of the global terrestrial biosphere and carbon storage over the last glacial-interglacial cycle. Global modelled (BIOME4) biome distributions over time generally agree well with those inferred from pollen data. The two climate models show good agreement in global net primary productivity (NPP). NPP is strongly influenced by atmospheric carbon dioxide (CO2) concentrations through CO2 fertilization. The combined effects of modelled changes in vegetation and (via a simple model) soil carbon result in a global terrestrial carbon storage at the Last Glacial Maximum that is 210-470 Pg C less than in pre-industrial time. Without the contribution from exposed glacial continental shelves the reduction would be larger, 330-960 Pg C. Other intervals of low terrestrial carbon storage include stadial intervals at 108 and 85 ka BP, and between 60 and 65 ka BP during Marine Isotope Stage 4. Terrestrial carbon storage, determined by the balance of global NPP and decomposition, influences the stable carbon isotope composition (δ13C) of seawater because terrestrial organic carbon is depleted in 13C. Using a simple carbon-isotope mass balance equation we find agreement in trends between modelled ocean δ13C based on modelled land carbon storage, and palaeo-archives of ocean δ13C, confirming that terrestrial carbon storage variations may be important drivers of ocean δ13C changes.

  7. 50-kyr vegetation history in the western Verkhoyansk Mountains region (NE Asia) reconstructed from fossil pollen data

    NASA Astrophysics Data System (ADS)

    Müller, Stefanie; Tarasov, Pavel E.; Andreev, Andrei A.; Tütken, Thomas; Gartz, Steffi; Diekmann, Bernhard

    2010-05-01

    A detailed radiocarbon-dated pollen record from Lake Billyakh (65°17'N, 126°47'E; 340 m a.s.l.) situated in the western part of the Verkhoyansk Mountains, about 140 km south of the Arctic Circle is presented. A set of 53 surface pollen samples representing tundra, cold-deciduous forest and taiga was collected in northern and central Yakutia communities to verify the accuracy of the quantitative biome reconstruction method and to obtain a more precise attribution of the identified pollen taxa to the main regional biomes. The adjusted method is then applied to the pollen record from Lake Billyakh to gain an objective reconstruction of vegetation and environments since about 50.7 kyr BP. The results of the pollen analysis and pollen-based biome reconstruction suggest that herbaceous tundra and steppe communities dominated the area from 50.7 to 13.5 kyr BP. The lowest pollen percentages of woody taxa and the highest values of Artemisia pollen attest that the 31-15 kyr BP period as the driest and coldest interval of the entire record. A relative high content of taxa representing shrub tundra communities and the presence of larch pollen recorded prior to 31 kyr and after 13.5 kyr BP likely indicate interstadial climate amelioration associated with the middle and latest parts of the last glacial. An increase in pollen percentages of herbaceous taxa around 12 kyr BP suggests broader distribution of drier communities in response to the colder and drier than present climate of the Younger Dryas. The onset of the Holocene is marked by the highest values of shrub taxa, mainly Betula sect. Nanae/Fruticosae. Pollen percentages of arboreal taxa increase gradually and reach maximum values after 7 kyr BP. The latter maximum mainly reflects the spread of Pinus sylvestris in central Yakutia as a response to the mid-Holocene climatic optimum. The quasi-continuous presence of larch, shrubby birch and alder pollen throughout the whole record is the most striking feature of the pollen

  8. 130 kyr of Dust Fluxes in the Equatorial Pacific: Implications for ITCZ movement and intensity

    NASA Astrophysics Data System (ADS)

    Jacobel, A. W.; Costa, K.; McManus, J. F.; Winckler, G.; Anderson, R. F.

    2015-12-01

    The position of the Intertropical Convergence Zone (ITCZ) has been hypothesized to play a role in linking the climate of the poles to the tropics and in predicating important changes in ocean overturning, particularly on deglacial timescales. One method of tracking the paleo-position of the ITCZ is through the quantification of 230Thxs,0-normalized 232Th concentrations in marine sediments which act as proxy for aeolian dust flux. Because the ITCZ is an efficient scavenger of atmospheric particulates, changes in the latitude of maximum dust flux can yield insight into variations in ITCZ position. This technique has been successfully utilized to reconstruct the movement of the ITCZ during the last deglaciation in the eastern equatorial Pacific (McGee et al., 2007). In this study we apply a similar approach to produce a high-resolution reconstruction of ITCZ movement in the central equatorial Pacific over the last 130 kyr, including the last glacial inception, Marine Isotope Stage 4, the Last Glacial Maximum and Termination I (TI). We present records of 232Th/230Thxs,0 as a proxy for continentally sourced dust at sub-millennial resolution along a latitudinal transect of three sites beneath the shifting ITCZ. We pair our new data with existing dust flux data from Antarctica, Greenland and the North Pacific to differentiate between changes in the ITCZ and variability in atmospheric dust abundance. Our data reconstruct a spatially different pattern of ITCZ movement during the last two deglaciations, which allows us to locate our records in the context of recent studies challenging our mechanistic understanding of deglacial terminations. Additionally, our data show evidence of precessional forcing in reconstructed dust fluxes, and we evaluate changes in ITCZ precipitation intensity (scavenging efficiency) and enhanced aeolian transport in tropical dust source regions as the driver of this variability.D. McGee, F. Marcantonio, and J. Lynch-Stieglitz, "Deglacial Changes in

  9. Dust fertilization of biological productivity in the Subarctic North Pacific during the last 150 kyr

    NASA Astrophysics Data System (ADS)

    Serno, S.; Winckler, G.; Anderson, R. F.; Ren, H. A.; Hayes, C.; Machalett, B.; Gersonde, R.; Haug, G. H.

    2012-12-01

    The Subarctic North Pacific (SNP) is one of three principal High Nutrient Low Chlorophyll regions of the modern ocean characterized by an excess pool of macronutrients not completely consumed during the annual biogeochemical cycle. In the last 25 years, a number of studies from the SNP have proposed that eolian dust input of iron from East Asian arid regions is the major limiting factor for primary and export production. In recent years, additional iron sources have been suggested for regulating phytoplankton growth in the SNP, including mobilized continental margin material, ice-rafted debris, volcanic material, turbulent mixing and upwelling. We will present results of a multi-proxy approach from INOPEX core SO202-7-6 and ODP site 882 from the Detroit Seamount in the northwest SNP covering the last 30 and 150 kyr, respectively. We will compare 230Th-normalized dust flux records based on 4He, 232Th and REE, grain size distributions and 230Th-normalized fluxes of opal, total organic carbon, carbonate and biogenic barium and Pa/Th ratios as productivity proxies for INOPEX core SO202-7-6. A new high resolution record of dust fluxes based on 4He will be compared with published productivity proxy records from ODP site 882. A spatial survey of core-top sediments covering the whole SNP indicates that the efficiency of diatom export out of the euphotic zone, as defined by the ratio of opal flux in the core-top sediments to the maximum annual surface water silicate concentration during the winter months, is positively correlated with dust fluxes, possibly as a result of either dust fertilization of primary production or a diatom ballasting effect by dust particles. Preliminary results from INOPEX core SO202-7-6, on the other hand, indicate no correlation between dust flux and biological productivity during the last deglaciation. We will discuss possible explanations for these observations to answer the question if the dust fertilization hypothesis proposed by John Martin

  10. Millennial-scale influence of southern intermediate component water into the North-east Atlantic during the last 40 kyr

    NASA Astrophysics Data System (ADS)

    Colin, Christophe; Frank, Norbert; Dubois-Dauphin, Quentin; Bonneau, Lucile; Montero-Serrano, Jean-Carlos; Blamart, Dominique; Van Rooij, David

    2014-05-01

    Throughout the last glacial-interglacial cycle major reorganisations of water masses in the North Atlantic occurred. Mediterranean Outflow Water (MOW) being an important source of saline and warm intermediate water has been modulated regarding its strength and mean depth. The Gulf of Cadiz near the Strait of Gibraltar is located in a region influenced by the 3 major temperate Atlantic mid-depth water masses: MOW, mid-depth subtropical gyre water and Antarctic Intermediate Water (AAIW). Those water masses are today characterized by contrasted Nd isotopic composition (ɛNd): NACW ɛNd = -11.9; MOW ɛNd= -9.4; AAIW ɛNd= -6 to -7. Here, we have investigated ɛNd of seawater and cold-water corals (L. pertusa, M. oculata and D. dianthus) located to the Alboran Sea and to the SE of the Gulf of Cadiz (between 550 and 850 m) to constrain the present day seawater ɛNd and to reconstruct the past water mass mixing, i.e. MOW variability during the last 37 kyr. Seawater ɛNd values of ~-11.6 indicate that the NACW is today the predominant water mass at the position of the coral bearing sediment core MD08-3231. Cold-water coral fragments have been 230Th/U dated yielding ages of 4.5 to 37 kyr. The coral ɛNd values range from -8 to -10.4 during the last 37 kyr, most likely indicating changes of the dominant water mass provenance. Glacial cold-water corals (from 19 to 37 kyr) are characterized by more radiogenic ɛNd values (> -9.5) compared to the ones from the Holocene demonstrating a decreasing contribution of MOW and/or AAIW in the SE Gulf of Cadiz during climate warming. Strikingly, Heinrich events H2 and H3 reveal even more radiogenic ɛNd values (~-8). In addition, deep-sea corals from the Alboran Sea indicate that ɛNd of the MOW do not change significantly trough time. These results imply a higher contribution of AAIW at 500 m depth in the eastern temperate Atlantic. This first coral based paleo-seawater ɛNd record for the Gulf of Cadiz thus points to significant

  11. Interpretation of palaeomonsoon dynamics on the Eastern Tibetan Plateau from a 10kyr peat record of dust deposition and regional atmospheric model simulations

    NASA Astrophysics Data System (ADS)

    Ferrat, M.; Weiss, D. J.; Dong, S.; Langmann, B.; Spiro, B.; Large, D.

    2010-12-01

    The eastern Qinghai-Tibetan Plateau is a climatically sensitive region, located today under the influence of the East Asian monsoon, the Indian summer monsoon and the westerlies. However, the evolution of atmospheric circulation patterns over this area through time remains poorly constrained due to the lack of information on changes in past wind trajectories and intensities. The study of this variability in climate archives is key to a better understanding of past Asian atmospheric dynamics and the refining of regional climate models. Our aim is to constrain Holocene palaeomonsoon dynamics over the eastern Qinghai-Tibetan Plateau through: 1) The geochemical study of atmospheric mineral dust deposited in a well-dated, continuous peat core; 2) The interpretation of results with respect to atmospheric simulations of dust transport under recent climatic scenarios using the regional climate model REMOTE. Dust mobilized by strong winds from the large deserts and sandy lands of northern China and India is transported over Asia by the different atmospheric currents and the study of mineral dust in our climate archive will allow us to: (a) quantify aeolian deposition, and hence study past wind strength; (b) identify the dominant dust sources (local, regional and long-range) through the application of geochemical provenance tracers, and hence study atmospheric pathways. Holocene dust fluxes in the peat core vary from 2-33 g m-2 y-1. Analysis of the dust record and surface samples from the potential source areas indicates that the europium anomaly, the ratios Y/Tb, Y/ΣREE, Sc/La, La/Th, Th/ ΣREE and Y/Er, as well as Pb isotopes (204Pb, 206Pb, 207Pb and 208Pb) are effective geochemical tracers to distinguish between the different dust sources. Results suggest that the deserts and loess deposits of northern China and the deserts of northwestern China dominated deposition to the core throughout the Holocene and particularly during the last 5kyr. Earlier deposition was also

  12. Dinocyst assemblage constraints on oceanographic and atmospheric processes in the eastern equatorial Atlantic over the last 44 kyr

    NASA Astrophysics Data System (ADS)

    Hardy, William; Penaud, Aurélie; Marret, Fabienne; Bayon, Germain; Marsset, Tania; Droz, Laurence

    2016-08-01

    A new 44 kyr long record of dinoflagellate (phytoplanktonic organisms) cysts (dinocysts) is presented from a marine sediment core collected on the Congolese margin with the aim of reconstructing past hydrological changes in the equatorial eastern Atlantic Ocean since Marine Isotopic Stage (MIS) 3. Our high-resolution dinocyst record indicates that significant temperature and moisture variations occurred across the glacial period, the last deglaciation and the Holocene. The use of specific dinocyst taxa, indicative of fluvial, upwelling and Benguela Current past environments for instance, provides insights into the main forcing mechanisms controlling palaeohydrological changes on orbital timescales. In particular, we are able, for the last 44 kyr, to correlate fluvial-sensitive taxa to monsoonal mechanisms related to precession minima-obliquity maxima combinations. While upwelling mechanisms appear as the main drivers for dinoflagellate productivity during MIS 2, dissolved nutrient-enriched Congo River inputs to the ocean also played a significant role in promoting dinoflagellate productivity between approximately 15.5 and 5 ka BP. Finally, this high-resolution dinocyst study permits us to precisely investigate the suborbital timing of the last glacial-interglacial termination, including an atypical warm and wet oceanic LGM signature, northern high-latitude abrupt climate change impacts in the equatorial eastern Atlantic, as well as a two-step decrease in moisture conditions during the Holocene at around 7-6 and 4-3.5 ka BP.

  13. Volcanic synchronisation of the EPICA-DC and TALDICE ice cores for the last 42 kyr BP

    NASA Astrophysics Data System (ADS)

    Severi, M.; Udisti, R.; Becagli, S.; Stenni, B.; Traversi, R.

    2012-03-01

    The age scale synchronisation between the Talos Dome and the EPICA Dome C ice cores was carried on through the identification of several common volcanic signatures. This paper describes the rigorous method, using the signature of volcanic sulphate, which was employed for the last 42 kyr of the record. Using this tight stratigraphic link, we transferred the EDC age scale to the Talos Dome ice core, producing a new age scale for the last 12 kyr. We estimated the discrepancies between the modelled TALDICE-1 age scale and the new scale during the studied period, by evaluating the ratio R of the apparent duration of temporal intervals between pairs of isochrones. Except for a very few cases, R ranges between 0.8 and 1.2, corresponding to an uncertainty of up to 20% in the estimate of the time duration in at least one of the two ice cores. At this stage our approach does not allow us to unequivocally identify which of the models is affected by errors, but, taking into account only the historically known volcanic events, we found that discrepancies up to 200 yr appear in the last two millennia in the TALDICE-1 model, while our new age scale shows a much better agreement with the volcanic absolute horizons. Thus, we propose for the Talos Dome ice core a new age scale (covering the whole Holocene) obtained by a direct transfer, via our stratigraphic link, from the EDC modelled age scale by Lemieux-Dudon et al. (2010).

  14. Volcanic synchronisation of the EPICA-DC and TALDICE ice cores for the last 42 kyr BP

    NASA Astrophysics Data System (ADS)

    Severi, M.; Udisti, R.; Becagli, S.; Stenni, B.; Traversi, R.

    2012-04-01

    An age scale synchronisation between the Talos Dome and the EPICA Dome C ice cores was carried on through the identification of several common volcanic signatures for the last 42 kyr. Using this tight stratigraphic link we transferred the EDC age scale to the Talos Dome ice core producing a new age scale for the last 12 kyr. We estimated the discrepancies between the modeled TALDICE-1 age scale and the new one during the studied period, by evaluating the ratio R of the apparent duration of temporal intervals between pairs of isochrones. Except for a very few cases, R ranges between 0.8 and 1.2 corresponding to an uncertainty of up to 20% in the estimate of the time duration in at least one of the two ice cores. At this stage our approach does not allow us unequivocally to find out which of the models is affected by errors, but, taking into account only the historically known volcanic events, we found that discrepancies up to 200 years appears in the last two millennia in the TALDICE-1 model, while our new age scale shows a much better agreement with the volcanic absolute horizons. Thus, we propose for the Talos Dome ice core a new age scale (covering the whole Holocene) obtained by a direct transfer, via our stratigraphic link, from the EDC modelled age scale by Lemieux-Dudon et al. (2010).

  15. Volcanic synchronisation of the EPICA-DC and TALDICE ice cores for the last 42 kyr BP

    NASA Astrophysics Data System (ADS)

    Severi, M.; Udisti, R.; Becagli, S.; Stenni, B.; Traversi, R.

    2011-10-01

    The age scale synchronisation between the Talos Dome and the EPICA Dome C ice cores was carried on through the identification of several common volcanic signatures. This paper describes the rigorous method, using the signature of volcanic sulphate, which was employed for the last 42 kyr of the record. Using this tight stratigraphic link we transferred the EDC age scale to the Talos Dome ice core producing a new age scale for the last 42 kyr. We estimated the discrepancies between the modeled TALDICE-1 age scale and the new one during the studied period, by evaluating the ratio R of the apparent duration of temporal intervals between pairs of isochrones. Except for a very few cases, R ranges between 0.8 and 1.2 corresponding to an uncertainty of up to 20% in the estimate of the time duration in at least one of the two ice cores. At this stage our approach does not allow us unequivocally to find out which of the models is affected by errors, but, taking into account only the historically known volcanic events, we found that discrepancies up to 200 yr appears in the last two millennia in the TALDICE-1 model, while our new age scale shows a much better agreement with the volcanic absolute horizons. Thus, we propose for the Talos Dome ice core a new age scale (covering the whole Holocene) obtained by a direct transfer, via our stratigraphic link, from the EDC modelled age scale.

  16. Silicic Eruptions of the Past 50 kyr at the Three Sisters Volcanic Cluster

    NASA Astrophysics Data System (ADS)

    Calvert, A. T.; Hildreth, W.; Fierstein, J.

    2003-12-01

    The Three Sisters volcanic cluster in the central Oregon Cascades consists of mafic to intermediate stratovolcanoes surrounded by mafic and silicic flows and domes. The bulk of South and Middle Sister are late Pleistocene while North Sister is middle Pleistocene (Schmidt and Grunder, 2003 GSA abs.). Thick rhyolite and dacite lava flows and domes are rich in potassium, and young glaciation exposes holocrystalline groundmass textures ideal for argon geochronology. Several of these silicic flows bracket stratovolcano growth, and precise geochronology illuminates a rich basalt to rhyolite history in the cluster over the past 50 kyr. Careful step-heating 40Ar/39Ar experiments yield excellent plateau ages with radiogenic yields often above 5% on rocks as young as 20 ka. Most samples have well-determined isochrons with atmospheric (40/36 = 295.5) intercepts, although several have intercepts as low as 286. South Sister is a composite cone with an andesite/dacite base (Hodge Crest) and a young andesite summit sequence. The basal flow of the 300m-thick, youngest conformable stack of andesite lavas at the summit is 27+/-3 ka. Unconformably underlying portions date back to at least 50 ka based on ages of overlapping silicic flows. The base of Middle Sister is andesite overlain by ˜300m of olivine basalt. Some Middle Sister andesites and all basalts overlie a distinctive dacite agglutinate (20+/-2 ka) in the South/Middle Sister saddle. All Middle Sister lavas underlie a thick dacite flow (14+/-3 ka) that vented at 8500 ft (2600m) on its S flank. Dacite lava flows erupted from the Middle/North Sister saddle at 27+/-2 and 18+/-2 ka. Additionally, several >100m-thick rhyolite and dacite lavas vented low on the flanks of the cluster. Obsidian Cliff rhyolite (37.8+/-1.8 ka) and Lane Plateau dacite (21.4+/-1.9 ka) erupted W of Middle Sister, the Dew Lake dacite (32.3+/-1.8 ka) located near the locus of the INSAR anomaly W of South Sister flowed around a 148+/-4 ka (knob 6482) basalt

  17. Mineralogical impact on organic nitrogen across a long-term soil chronosequence (0.3-4100 kyr)

    NASA Astrophysics Data System (ADS)

    Mikutta, Robert; Kaiser, Klaus; Dörr, Nicole; Vollmer, Antje; Chadwick, Oliver A.; Chorover, Jon; Kramer, Marc G.; Guggenberger, Georg

    2010-04-01

    Large portions of organic N (ON) in soil exist tightly associated with minerals. Mineral effects on the type of interactions, chemical composition, and stability of ON, however, are poorly understood. We investigated mineral-associated ON along a Hawaiian soil chronosequence (0.3-4100 kyr) formed in basaltic tephra under comparable climatic, topographic, and vegetation conditions. Mineral-organic associations were separated according to density ( ρ > 1.6 g/cm 3), characterized by X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge fine structure (NEXAFS) and analyzed for amino acid enantiomers and amino sugars. The 14C activity of mineral-bound OC was estimated by accelerator mass spectrometry. The close OC-ON relationship ( r = 0.96) and XPS results suggest that ON exists incorporated in bulk mineral-bound OM and likely becomes associated with minerals as part of sorbing OM. The youngest site (0.3 kyr), with soils mainly composed of primary minerals (olivine, pyroxene, feldspar) and with little ON, contained the largest proportion of hydrolyzable amino sugars and amino acids but with a small share of acidic amino acids (aspartic acid, glutamic acid). In soils of the intermediate weathering stage (20-400 kyr), where poorly crystalline minerals and metal(hydroxide)-organic precipitates prevail, more mineral-associated ON was present, containing a smaller proportion of hydrolyzable amino sugars and amino acids due to the preferential accumulation of other OM components such as lignin-derived phenols. Acidic amino acids were more abundant, reflecting the strong association of acidic organic components with metal(hydroxide)-organic precipitates and variable-charge minerals. In the final weathering stage (1400-4100 kyr) with well-crystalline secondary Fe and Al (hydr)oxides and kaolin minerals, mineral-organic associations held less ON and were, relative to lignin phenols, depleted in hydrolyzable amino sugars and amino acids, particularly in acidic

  18. The Padua Inventory: Do Revisions Need Revision?

    ERIC Educational Resources Information Center

    Gonner, Sascha; Ecker, Willi; Leonhart, Rainer

    2010-01-01

    The purpose of the present study was to examine the psychometric properties, factorial structure, and validity of the Padua Inventory-Washington State University Revision and of the Padua Inventory-Revised in a large sample of patients with obsessive-compulsive disorder (n = 228) and with anxiety disorders and/or depression (n = 213). The…

  19. Observation of 23 Supernovae that Exploded <300 pc from Earth During the Past 300 kyr in the Radiocarbon and 10Be Cosmogenic Isotope Record

    NASA Astrophysics Data System (ADS)

    Firestone, R. B.

    2014-12-01

    The global excess radiocarbon abundance record for the past 50 kyr can be entirely explained by the explosion of four supernovae 44, 37, 32, and 22 kyr ago less than 250 pc from Earth. Each supernova left a nearly identical signature beginning with a sudden increase at the time of the explosion, followed by a hiatus of 1500 years, and continuing with a sustained, 2000 year increase in radiocarbon from gamma rays produced by diffusive shock in the supernova remnant. For the past 18 kyr excess radiocarbon from SN22kyrBP, identified as the Vela supernova, has decayed with the 5700 year half-life of 14C. The absolute scale for radiocarbon abundance has been determined from the decay curve as Δ14C=5±2% in 1950. Small oscillations in the decay curve are shown to coincide with variations in Earth's Virtual Axial Dipole Moment (VADM). SN44kyrBP exploded approximately 110 pc from Earth doubling the radiocarbon abundance. These supernovae are confirmed in the 10Be, 26Al, 36Cl and nitrate geological records. An additional 19 supernovae are observed 50-300 kyr ago in the 10Be record. Using the Earth as a calorimeter I have determined that approximated 2×1049 ergs were released at the time of each supernova explosion and 1049-50 ergs afterwards, consistent with theoretical predictions. The background rate of radiocarbon productions from more distant sources was determined as 1.61 atoms/cm2s at the top of the atmosphere. Although little danger to life on Earth is expected from these supernovae, each of the recent events were shown to correlate with concurrent global warming of 3-4°C.

  20. The Environmental impact of the 8.2 and 9.2 kyr events in the UK.

    NASA Astrophysics Data System (ADS)

    Jones, Richard; Reinhardt, Liam; Halloran, Paul; Hatton, Jackie; Marshall, Jim

    2015-04-01

    The instability of the Early Holocene climate in NW Europe is due in part to the impact of freshwater pulses in the North Atlantic disrupting thermohaline circulation and reducing the northward transport of heat. Two of the most significant climatic episodes are the 8.2 and 9.2 kyr events, characterised by significant oxygen isotopic excursions in NW European lacustrine and speleothem records, the Greenland Ice-core record and changing SSTs in the North Atlantic sector. Assessing the impact of these two events on terrestrial systems is problematic due to the difficulty in identifying their signature in terrestrial archives. A sub-decadal oxygen isotope record from a Holocene micrite core from Hawes Water NW England provides unambiguous evidence for two significant isotopic excursions equivalent to the 9.2 and 8.2 kyr events. Lasting 50 and 150 yr respectively they are characterised by a slight cooling of around 1.6oC in mean July air temperatures (chironomid inferred). The environmental impact of each event was minimal, with no evidence for any significant changes in the range or abundance of plant taxa and no evidence for catchment instability. These results support the idea that the 8.2 and 9.2 kyr events are primarily a reflection of the changing isotopic composition of meteoric precipitation (δ18Op) and in the UK at least were of limited environmental significance. Analysis of subpolar gyre behaviour and atmospheric circulation across preindustrial control simulations from CMIP5, suggest that the negative isotopic excursions recorded at Hawes Water most likely reflect the influx of isotopically lighter moisture from the Arctic. An influx of freshwater down the Hudson River and into the North Atlantic Current could result in the development of low pressure anomalies over Scandinavia, bringing arctic air and moisture to the UK. This could be expected to produce the relatively minor decline in summer temperatures but would result in the significant negative shift

  1. Impact of climate variability on terrestrial environment in Western Europe between 45 and 9 kyr cal. BP: vegetation dynamics recorded by the Bergsee Lake (Black Forest, Germany).

    NASA Astrophysics Data System (ADS)

    Duprat-Oualid, Fanny; Begeot, Carole; Rius, Damien; Millet, Laurent; Magny, Michel

    2016-04-01

    Between 9 and 45 kyr cal. BP, two great transitions lead the global climate system to evolve from the Last-Glacial period (115-14.7 kyr cal. BP), to two successive warmer periods, the Late-Glacial Interstadial (14.7-11.7 kyr cal. BP) and the Holocene (11.7-0 kyr cal. BP). δ18O variations recorded in Greenland ice cores (GRIP & NGRIP) revealed high frequency climate variability within the Last Glacial. These reference isotopic records highlighted a succession of centennial-to-millennial warm/cold events, the so-called Greenland Interstadials (GI) and Greenland Stadials (GS). The number continental records about the period 14.7-0 kyr cal. BP is substantial. This allowed to understand the vegetation dynamics in response to climate changes this period at the North-Atlantic scale. However, sequences covering the glacial period (beyond 20 kyr cal.BP) remain rare, because of hiatuses mostly due to local glaciers. Therefore, sedimentary continuous records of vegetation dynamics are still needed to better understand climate changes during the Last Glacial in Western Europe (Heiri et al. 2014). Here we present a new high-resolution pollen record from Lake Bergsee (47°34'20''N, 7°56'11''E, 382 m a.s.l). This lake is located south of Black Forest and north of the Alps, beyond the zone of glaciers maximal extension. Therefore it could have recorded the whole last climatic cycle, i.e. 120-0 kyr cal. BP. In 2013, a 29 m long core was extracted from the Bergsee. According to the depth-age model based on 14C AMS dating and the Laacher See Tephra (LST), the record spans continuously at least the last 45 kyrs. The first series of pollen analysis, focused on the 45-9 kyr cal. BP time window, allows us to reconstruct a precise, faithful and continuous vegetation history at the centennial scale. This high temporal resolution enabled to assess the response of vegetation to secular climate events (e.g. GI-4 = 200 yrs). First, our results show that vegetation responded to climate

  2. A Revised Holocene History of Lake Kivu, East Africa

    NASA Astrophysics Data System (ADS)

    Votava, J. E.; Johnson, T. C.; Hecky, R. E.

    2013-12-01

    The great lakes of the East African Rift valley are a vast chain of lakes formed in a region of active tectonics. These large, deep lakes are relatively old and many (e.g. Tanganyika, Malawi, and Turkana) have greatly influenced our understanding of terrestrial, tropical East African paleoclimate. Lake Kivu (max depth, 485m) sits at the heart of these rift lakes, north of Lake Tanganyika between the Democratic Republic of the Congo and Rwanda (roughly 250 km west of Lake Victoria). At over 1,400 meters in elevation, this 2,060 km2 mesotrophic lake has a complex stratification regime imposed by hydrothermal springs and deep waters supersaturated at STP in CO2 and CH4 gasses. The active Virunga Volcanoes to the north of the lake supply heated, high-salinity waters below 280 meters water depth maintaining the modern crenogenic meromixis. Based on detailed studies of diatom assemblages and bulk sedimentology, previous workers have suggested this hydrothermal activity began roughly 5,000 years BP. Unfortunately, dating and stratigraphic correlations of these original cores from the 1970 Woods Hole Oceanographic Institution's expedition have been problematic. Here we offer an improved chronology and new carbonate analyses from cores recovered in 2012 and 2013. Our AMS radiocarbon ages come from six terrigeneous macrofossils spanning the last 9,100 years (cal BP). These ages suggest a rather high sedimentation rate on the order of 70cm/kyr, and hence, our 8 m-long core provides us with a high-resolution lake history for the past 10,000 years. Most notable over the past 5,000 years in the lake history is the repeated onset and cessation of carbonate deposition, punctuated by organic-rich intervals. Earlier studies of the Woods Hole cores placed the onset of carbonate deposition at ca. 11,000 years BP suggesting changes in lake hydrology (i.e. closed to open), while the abrupt cessation of carbonate was dated at ca. 5,000 years BP and attributed to the beginning of

  3. Sea ice and millennial-scale climate variability in the Nordic seas 90 kyr ago to present.

    PubMed

    Hoff, Ulrike; Rasmussen, Tine L; Stein, Ruediger; Ezat, Mohamed M; Fahl, Kirsten

    2016-01-01

    In the light of rapidly diminishing sea ice cover in the Arctic during the present atmospheric warming, it is imperative to study the distribution of sea ice in the past in relation to rapid climate change. Here we focus on glacial millennial-scale climatic events (Dansgaard/Oeschger events) using the sea ice proxy IP25 in combination with phytoplankton proxy data and quantification of diatom species in a record from the southeast Norwegian Sea. We demonstrate that expansion and retreat of sea ice varies consistently in pace with the rapid climate changes 90 kyr ago to present. Sea ice retreats abruptly at the start of warm interstadials, but spreads rapidly during cooling phases of the interstadials and becomes near perennial and perennial during cold stadials and Heinrich events, respectively. Low-salinity surface water and the sea ice edge spreads to the Greenland-Scotland Ridge, and during the largest Heinrich events, probably far into the Atlantic Ocean.

  4. Cosmic airburst debris, climate anomalies and societal reactions at 4.2kyr BP: from North Syria to Adelie Land

    NASA Astrophysics Data System (ADS)

    Coqueugniot, E.; Courty, M. M.

    2012-12-01

    The linkages established between dust spikes, unprecedented drought and societal disruption at 4.2 kyr BP have yet failed elucidating the marked increase in aerosol. The volcanic dust component or the erratic spatial pattern are among other puzzling anomalies for a global climate event. We examine here the 4.2 kyr BP debris records from high quality sedimentary archives across the two hemispheres: (1) at Tell Dja'de (Syria), a carbonaceous surface sealed by a EB III/IV Bronze age cemetery; (2) at Tell Ahmar (Syria), the nearly intact collapsed wood frame of the Akkad palace sandwiched between the last 3rd millennium BC plastered floors and massive destruction layers of the monumental buildings; (3) debris accumulation from human processed slags in late Akkaddian contexts at Tell Leilan, Tell Chuera, Tell Beydar, Tell Brak (North Syria) and in an EB III/IV one at Umbaschi (South Syria); (4) a tsunami layer at Banda Aceh (Sumatra); (5) deep sea cores from the Mediterranean and Caspian seas, the Indian and Austral oceans. Using an in situ multi-analytical protocol, we focus on the carbonaceous polymorphs and the composite elements that we formerly defined to tracing hypervelocity cosmic airbursts. A meticulous control of their spatial pattern and structural characteristics at meso to nano-scales has helped to distinguishing the intact debris fall of airburst origin from their human processed-byproducts. The later trace the occurrence in the debris airbursts of highly valuable resources, i.e. fossil combustible with singular properties, that have been exploited since the prehistoric time. Evidence for an oceanic impact at 4.2 kyr BP in the Austral ocean are provided by the 3 m record in the Adelie land high resolution marine core (MD03-2601) showing sudden discharge of ice rafted fine debris with impact features. Their fresh fingerprints in the high to low latitude records from the southern hemisphere indicate massive dispersion of impact debris by air and surface

  5. A complete terrestrial radiocarbon record for 11.2 to 52.8 kyr B.P.

    PubMed

    Bronk Ramsey, Christopher; Staff, Richard A; Bryant, Charlotte L; Brock, Fiona; Kitagawa, Hiroyuki; van der Plicht, Johannes; Schlolaut, Gordon; Marshall, Michael H; Brauer, Achim; Lamb, Henry F; Payne, Rebecca L; Tarasov, Pavel E; Haraguchi, Tsuyoshi; Gotanda, Katsuya; Yonenobu, Hitoshi; Yokoyama, Yusuke; Tada, Ryuji; Nakagawa, Takeshi

    2012-10-19

    Radiocarbon ((14)C) provides a way to date material that contains carbon with an age up to ~50,000 years and is also an important tracer of the global carbon cycle. However, the lack of a comprehensive record reflecting atmospheric (14)C prior to 12.5 thousand years before the present (kyr B.P.) has limited the application of radiocarbon dating of samples from the Last Glacial period. Here, we report (14)C results from Lake Suigetsu, Japan (35°35'N, 135°53'E), which provide a comprehensive record of terrestrial radiocarbon to the present limit of the (14)C method. The time scale we present in this work allows direct comparison of Lake Suigetsu paleoclimatic data with other terrestrial climatic records and gives information on the connection between global atmospheric and regional marine radiocarbon levels.

  6. Sea ice and millennial-scale climate variability in the Nordic seas 90 kyr ago to present

    NASA Astrophysics Data System (ADS)

    Hoff, Ulrike; Rasmussen, Tine L.; Stein, Ruediger; Ezat, Mohamed M.; Fahl, Kirsten

    2016-07-01

    In the light of rapidly diminishing sea ice cover in the Arctic during the present atmospheric warming, it is imperative to study the distribution of sea ice in the past in relation to rapid climate change. Here we focus on glacial millennial-scale climatic events (Dansgaard/Oeschger events) using the sea ice proxy IP25 in combination with phytoplankton proxy data and quantification of diatom species in a record from the southeast Norwegian Sea. We demonstrate that expansion and retreat of sea ice varies consistently in pace with the rapid climate changes 90 kyr ago to present. Sea ice retreats abruptly at the start of warm interstadials, but spreads rapidly during cooling phases of the interstadials and becomes near perennial and perennial during cold stadials and Heinrich events, respectively. Low-salinity surface water and the sea ice edge spreads to the Greenland-Scotland Ridge, and during the largest Heinrich events, probably far into the Atlantic Ocean.

  7. Stratigraphic Correlation of an Excursion at 22 kyr in the U.S. Great Basin - the Hilina Pali Excursion?

    NASA Astrophysics Data System (ADS)

    Liddicoat, J. C.; Coe, R. S.

    2013-12-01

    An unusually large secular variation of the geomagnetic field recorded in outcrops of pluvial Lake Russell sediment about 22 kyr old in the Mono Basin, CA, can be used for precise correlation to other lacustrine sections in the western U.S., and perhaps beyond. We present new AF and thermal demagnetization results for paired samples at 2-cm intervals between ash layers 7 and 8 of Lajoie (1968) in the bank of Wilson Creek that document an excursion having an inclination as low as 16 degrees and as high as 73 degrees, while the declination swings from 15 degrees west during the low inclination to 30 east when the inclination is high, and back to average northerly declination and expected inclination. The corresponding VGPs form a narrow clockwise-trending loop centered at about 50 N, 30 E. The Mono Lake Excursion (MLE; Liddicoat and Coe, 1979) occurs 1.7 m lower in the same section. The best estimates for the ages of the two excursions are about 22 and 32 kyr, based on 14-C dates (Cassata et al., 2010). About 150 km to the north, sediments of about the same age exposed along the Truckee River that were deposited in pluvial Lake Lahontan record a similar geomagnetic signature. Moreover, both the MLE and this excursion are exhibited at the appropriate levels in a sediment core taken from Pyramid Lake, the remnant of Lake Lahontan (Benson et al., 2008). Thus, this excursion is a valuable marker for high-resolution correlation of Quaternary sediments in the western U.S., especially when paired with the MLE. It is tempting to try to identify this geomagnetic feature with others of about the same age further away. On the island of Hawaii, Coe et al. (1978) discovered a lava flow on the Hilina Pali with a calibrated 14-C age of 21 +/-1 kyr that has an inclination about 30 degrees shallower and a paleointensity 60 percent lower than today. Later Teanby et al. (2002) documented an excursion with inclinations as low as -35 degrees, recorded by around 40 successive flows with

  8. Modelling 100 kyr of transient climate change during the Pliocene (MIS M2 to MIS KM5c)

    NASA Astrophysics Data System (ADS)

    Hunter, S. J.; Dolan, A. M.; Haywood, A. M.

    2014-12-01

    The mid-Pliocene warm period (3.264-3.025 Ma) is a key target for palaeoclimate modellers in the investigation of warm intervals in Earth history. This research is driven by the need to evaluate climate models against geological data in order to assess model performance in warmer than present climates. The mid-Pliocene has generally been modelled using fixed-boundary condition climate model experiments, such as those performed for the Pliocene Model Intercomparison Project (PlioMIP). This means that orbital-timescale variability in climate is often overlooked. In the past data-model comparisons have primarily focussed on comparing snap-shot experiments (fixed boundary conditions) with time-averaged data (for example PRISM3 data which is representative of an average of ~250,000 years). In order to improve the validity of proxy-data and model comparisons it is critical that we move towards climate simulations that better capture changing bounding conditions occurring over orbital timescales and compare these with timeseries data. Here, we present two sets of transient simulations; the first is centred on the warm interglacial peak, MIS KM5c (+/-20 kyr) whilst the second runs from the glacial peak MIS M2 through to MIS KM5c (~100 kyr). We use the full-complexity intermediate-resolution FAMOUS climate model driven by PRISM3 boundary conditions (which were also used in PlioMIP phase 1). Our initial experiments apply a changing orbit, with and without dynamic vegetation. We present an overview of climate variability during these time windows, but also discuss the difficulties that have been faced in such modelling and detail some ideal future directions to explore

  9. Nuclear Power and the Environment: Questions and Answers. Revised.

    ERIC Educational Resources Information Center

    Campana, Robert J.; Langer, Sidney

    This publication is a complete revision of an earlier booklet brought on by the dramatic changes in the energy outlook of the United States that occurred in 1973 and 1974. The purpose of this document is to inform the public on the overall U.S. energy situation, in particular electricity generated from nuclear reactors and other sources. The…

  10. Opticalman 1 and C, Rate Training Manual. [1972 Revised Edition].

    ERIC Educational Resources Information Center

    Naval Personnel Program Support Activity, Washington, DC.

    In this revised edition of an earlier publication (ED 070 574), fundamentals of optical instruments on board ships are presented in this rate training manual for regular navy and naval reserve personnel. The manual includes nine chapters: Introduction; Administration and Supervision; Nature of Light; Optical Alignment Instruments; Night Vision…

  11. Revision and Factor Analysis of a Death Anxiety Scale.

    ERIC Educational Resources Information Center

    Thorson, James A.; Powell, F. C.

    Earlier research on death anxiety using the 34-item scale developed by Nehrke-Templer-Boyar (NTB) indicated that females and younger persons have significantly higher death anxiety. To simplify a death anxiety scale for use with different age groups, and to determine the conceptual factors actually measured by the scale, a revised 25-item…

  12. 3/4 view of newer station's south and east elevations. Earlier ...

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

    3/4 view of newer station's south and east elevations. Earlier photos taken from the tower atop this structure. - Vermilion Life Saving Station, Shore of Lake Superior, 10 miles west of Whitefish Point, Paradise, Chippewa County, MI

  13. Integrated Tree-Ring-Radiocarbon High-Resolution Timeframe to Resolve Earlier Second Millennium BCE Mesopotamian Chronology.

    PubMed

    Manning, Sturt W; Griggs, Carol B; Lorentzen, Brita; Barjamovic, Gojko; Ramsey, Christopher Bronk; Kromer, Bernd; Wild, Eva Maria

    2016-01-01

    500 years of ancient Near Eastern history from the earlier second millennium BCE, including such pivotal figures as Hammurabi of Babylon, Šamši-Adad I (who conquered Aššur) and Zimrilim of Mari, has long floated in calendar time subject to rival chronological schemes up to 150+ years apart. Texts preserved on clay tablets provide much information, including some astronomical references, but despite 100+ years of scholarly effort, chronological resolution has proved impossible. Documents linked with specific Assyrian officials and rulers have been found and associated with archaeological wood samples at Kültepe and Acemhöyük in Turkey, and offer the potential to resolve this long-running problem. Here we show that previous work using tree-ring dating to place these timbers in absolute time has fundamental problems with key dendrochronological crossdates due to small sample numbers in overlapping years and insufficient critical assessment. To address, we have integrated secure dendrochronological sequences directly with radiocarbon (14C) measurements to achieve tightly resolved absolute (calendar) chronological associations and identify the secure links of this tree-ring chronology with the archaeological-historical evidence. The revised tree-ring-sequenced 14C time-series for Kültepe and Acemhöyük is compatible only with the so-called Middle Chronology and not with the rival High, Low or New Chronologies. This finding provides a robust resolution to a century of uncertainty in Mesopotamian chronology and scholarship, and a secure basis for construction of a coherent timeframe and history across the Near East and East Mediterranean in the earlier second millennium BCE. Our re-dating also affects an unusual tree-ring growth anomaly in wood from Porsuk, Turkey, previously tentatively associated with the Minoan eruption of the Santorini volcano. This tree-ring growth anomaly is now directly dated ~1681-1673 BCE (68.2% highest posterior density range), ~20

  14. Integrated Tree-Ring-Radiocarbon High-Resolution Timeframe to Resolve Earlier Second Millennium BCE Mesopotamian Chronology

    PubMed Central

    Griggs, Carol B.; Lorentzen, Brita; Barjamovic, Gojko; Ramsey, Christopher Bronk; Kromer, Bernd; Wild, Eva Maria

    2016-01-01

    500 years of ancient Near Eastern history from the earlier second millennium BCE, including such pivotal figures as Hammurabi of Babylon, Šamši-Adad I (who conquered Aššur) and Zimrilim of Mari, has long floated in calendar time subject to rival chronological schemes up to 150+ years apart. Texts preserved on clay tablets provide much information, including some astronomical references, but despite 100+ years of scholarly effort, chronological resolution has proved impossible. Documents linked with specific Assyrian officials and rulers have been found and associated with archaeological wood samples at Kültepe and Acemhöyük in Turkey, and offer the potential to resolve this long-running problem. Here we show that previous work using tree-ring dating to place these timbers in absolute time has fundamental problems with key dendrochronological crossdates due to small sample numbers in overlapping years and insufficient critical assessment. To address, we have integrated secure dendrochronological sequences directly with radiocarbon (14C) measurements to achieve tightly resolved absolute (calendar) chronological associations and identify the secure links of this tree-ring chronology with the archaeological-historical evidence. The revised tree-ring-sequenced 14C time-series for Kültepe and Acemhöyük is compatible only with the so-called Middle Chronology and not with the rival High, Low or New Chronologies. This finding provides a robust resolution to a century of uncertainty in Mesopotamian chronology and scholarship, and a secure basis for construction of a coherent timeframe and history across the Near East and East Mediterranean in the earlier second millennium BCE. Our re-dating also affects an unusual tree-ring growth anomaly in wood from Porsuk, Turkey, previously tentatively associated with the Minoan eruption of the Santorini volcano. This tree-ring growth anomaly is now directly dated ~1681–1673 BCE (68.2% highest posterior density range), ~20

  15. Integrated Tree-Ring-Radiocarbon High-Resolution Timeframe to Resolve Earlier Second Millennium BCE Mesopotamian Chronology.

    PubMed

    Manning, Sturt W; Griggs, Carol B; Lorentzen, Brita; Barjamovic, Gojko; Ramsey, Christopher Bronk; Kromer, Bernd; Wild, Eva Maria

    2016-01-01

    500 years of ancient Near Eastern history from the earlier second millennium BCE, including such pivotal figures as Hammurabi of Babylon, Šamši-Adad I (who conquered Aššur) and Zimrilim of Mari, has long floated in calendar time subject to rival chronological schemes up to 150+ years apart. Texts preserved on clay tablets provide much information, including some astronomical references, but despite 100+ years of scholarly effort, chronological resolution has proved impossible. Documents linked with specific Assyrian officials and rulers have been found and associated with archaeological wood samples at Kültepe and Acemhöyük in Turkey, and offer the potential to resolve this long-running problem. Here we show that previous work using tree-ring dating to place these timbers in absolute time has fundamental problems with key dendrochronological crossdates due to small sample numbers in overlapping years and insufficient critical assessment. To address, we have integrated secure dendrochronological sequences directly with radiocarbon (14C) measurements to achieve tightly resolved absolute (calendar) chronological associations and identify the secure links of this tree-ring chronology with the archaeological-historical evidence. The revised tree-ring-sequenced 14C time-series for Kültepe and Acemhöyük is compatible only with the so-called Middle Chronology and not with the rival High, Low or New Chronologies. This finding provides a robust resolution to a century of uncertainty in Mesopotamian chronology and scholarship, and a secure basis for construction of a coherent timeframe and history across the Near East and East Mediterranean in the earlier second millennium BCE. Our re-dating also affects an unusual tree-ring growth anomaly in wood from Porsuk, Turkey, previously tentatively associated with the Minoan eruption of the Santorini volcano. This tree-ring growth anomaly is now directly dated ~1681-1673 BCE (68.2% highest posterior density range), ~20

  16. Three exceptionally strong East-Asian summer monsoon events during glacial times in the past 470 kyr

    NASA Astrophysics Data System (ADS)

    Rousseau, D.-D.; Wu, N.; Pei, Y.; Li, F.

    2009-04-01

    Chinese loess sequences are interpreted as a reliable record of the past variation of the East Asian monsoon regime through the alternation of loess and paleosols units, dominated by the winter and summer monsoon, respectively. Different proxies have been used to describe this system, mostly geophysical, geochemical or sedimentological. Terrestrial mollusks are also a reliable proxy of past environmental conditions and are often preserved in large numbers in loess deposits. The analysis of the mollusk remains in the Luochuan sequence, comprising L5 loess to S0 soil, i.e. the last 500 ka, shows that for almost all identified species, the abundance is higher at the base of the interval (L5 to L4) than in the younger deposits. Using the present ecological requirements of the identified mollusk species in the Luochuan sequence allows the definition of two main mollusk groups varying during the last 500 kyr. The cold-aridiphilous individuals indicate the so-called Asian winter monsoon regime and predominantly occur during glacials, when dust is deposited. The thermal-humidiphilous mollusks are prevalent during interglacial or interstadial conditions of the Asian summer monsoon, when soil formation takes place. In the sequence, three events with exceptionally high abundance of the Asian summer monsoon indicators are recorded during the L5, L4 and L2 glacial intervals, i.e., at about 470, 360 and 170 kyr, respectively. The L5 and L4 events appear to be the strongest (high counts). Similar variations have also been identified in the Xifeng sequence, distant enough from Luochuan, but also in Lake Baikal further North, to suggest that this phenomenon is regional rather than local. The indicators of the summer monsoon within the glacial intervals imply a strengthened East-Asian monsoon interpreted as corresponding to marine isotope stages 12, 10 and 6, respectively. The L5 and L2 summer monsoons are coeval with Mediterranean sapropels S12 and S6, which characterize a strong

  17. Three exceptionally strong East-Asian summer monsoon events during glacial times in the past 470 kyr

    NASA Astrophysics Data System (ADS)

    Rousseau, D.; Wu, N.; Pei, Y.; Li, F.

    2009-12-01

    Chinese loess sequences are interpreted as a reliable record of the past variation of the East Asian monsoon regime through the alternation of loess and paleosols units, dominated by the winter and summer monsoon respectively. Different proxies have been used to describe this system, mostly geophysical, geochemical or sedimentological. Terrestrial mollusks are also a reliable proxy of past environmental conditions and are often preserved in large numbers in loess deposits. The analysis of the mollusk remains in the Luochuan sequence, comprising L5 loess to S0 soil, i.e. the last 500 ka, shows that for almost all identified species, the abundance is higher at the base of the interval (L5 to L4) than in the younger deposits. Using the present ecological requirements of the identified mollusk species in the Luochuan sequence allows the definition of two main mollusk groups varying during the last 500 kyr. In the sequence, three events with exceptionally high abundance of the Asian summer monsoon indicators (thermal-humidiphilous mollusks) are recorded during the L5, L4 and L2 glacial intervals, i.e., at about 470, 360 and 170 kyr respectively. The L5 and L4 events appear to be the strongest (high counts). Similar variations have also been identified in E Asia to suggest that this phenomenon is regional rather than local. The L5 and L2 summer monsoons are coeval with Mediterranean sapropels S12 and S6, which characterize a strong African summer monsoon with relatively low surface water salinity in the Indian Ocean. Changes in the precipitation regime could correspond to a response to a particular astronomical configuration (low obliquity, low precession, summer solstice at perihelion) leading to an increased summer insolation gradient between the tropics and the high latitudes and resulting in enhanced atmospheric water transport from the tropics to the African and Asian continents. However, other climate drivers such as reorganization of marine and atmospheric

  18. Three exceptionally strong East-Asian summer monsoon events during glacial conditions in the past 470 kyr

    NASA Astrophysics Data System (ADS)

    Rousseau, D.-D.; Wu, N.; Pei, Y.; Li, F.

    2008-12-01

    Chinese loess sequences are interpreted as a reliable record of the past variation of the East Asian monsoon regime through the alternation of loess and paleosols units, dominated by the winter and summer monsoon, respectively. Different proxies have been used to describe this system, mostly geophysical, geochemical or sedimentological. Terrestrial mollusks are also a reliable proxy of past environmental conditions and are often preserved in large numbers in loess deposits. The analysis of the mollusk remains in the Luochuan sequence, comprising L5 loess to S0 soil, i.e. the last 500 ka, shows that for almost all identified species, the abundance is higher at the base of the interval (L5 to L4) than in the younger deposits. Using the present ecological requirements of the identified mollusk species in the Luochuan sequence allows the definition of two main mollusk groups varying during the last 500 kyr. The cold-aridiphilous individuals indicate the so-called Asian winter monsoon regime and predominantly occur during glacials, when dust is deposited. The thermal-humidiphilous mollusks are prevalent during interglacial or interstadial conditions of the Asian summer monsoon, when soil formation takes place. In the sequence, three events with exceptionally high abundance of the Asian summer monsoon indicators are recorded during the L5, L4 and L2 glacial intervals, i.e., at about 470, 360 and 170 kyr, respectively. The L5 and L4 events appear to be the strongest (high counts). Similar variations have also been identified in the Xifeng sequence, distant enough from Luochuan, but also in Lake Baikal further North, to suggest that this phenomenon is regional rather than local. The indicators of the summer monsoon within the glacial intervals imply a strengthened East-Asian monsoon interpreted as corresponding to marine isotope stages 6, 10 and 12, respectively. The L5 and L2 summer monsoons are coeval with Mediterranean sapropels S12 and S6, which characterize a strong

  19. Benthic foraminiferal δ18O-Mg/Ca from the SE Nordic seas during the last 65 kyr

    NASA Astrophysics Data System (ADS)

    Ezat, M.; Rasmussen, T. L.; Groeneveld, J.

    2013-12-01

    Benthic foraminiferal δ18O-Mg/Ca from the SE Nordic seas during the last 65 kyr Mohamed M. Ezat1,2*, Tine L. Rasmussen1, Jeroen Groeneveld3 1 CAGE - Centre for Arctic Gas Hydrate, Environment and Climate, and Department of Geology, University of Tromsø, NO-9037 Tromsø, Norway. 2 Department of Geology, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt. 3 Department of Geosciences, University of Bremen, Klagenfurter Strasse, 28359, Bremen, Germany. * e-mail: mohamed.ezat@uit.no The climate during the last glacial period underwent rapid millennial-scale variability known as Dansgaard-Oeschger (DO) events of warm interstadials and cold stadials. DO events are manifested in marine and continental records in the circum-North Atlantic region and throughout the globe. Several studies suggest a crucial role of the Nordic seas in regulating the climate during the last glacial period. Previous studies from the Nordic seas revealed low benthic δ18O values during stadials and high values during interstadials. The causes of the depletions in benthic 18O during stadials are highly debated. Sinking of isotope depleted-brines formed due to sea ice production has previously been proposed. Another explanation has indicated warming of the intermediate water in the Nordic seas based on the finding of warm water benthic foraminiferal species during stadials. Here we present the first benthic foraminiferal Mg/Ca-based bottom water temperature (BWT) record from the Nordic seas that, along with other proxies, aims to resolve the hydrographic changes at intermediate water depth on DO timescale during the last 65 kyr. The results show pronounced and gradual BWT increases during all cold stadials followed by an abrupt drop to modern-like BWT at interstadials onsets. The increase in BWT, caused by the subsurface inflow of warm Atlantic intermediate water, substantially contributed to the halocline collapse and onset of interstadial conditions throughout complex ocean-sea ice

  20. Multiproxy Records of Indo-Pacific Climate and Environmental Change from Lake Towuti, Indonesia, Since 60 Kyr BP

    NASA Astrophysics Data System (ADS)

    Russell, J. M.; Vogel, H.; Bijaksana, S.; Konecky, B. L.; Wicaksono, S. A.; Costa, K.; Wattrus, N. J.; Melles, M.

    2014-12-01

    Lake Towuti is a large tectonic lake in central Sulawesi, Indonesia that provides a unique opportunity to reconstruct climate and terrestrial environments in the heart of the Indo-Pacific warm pool. Long-term climate variations in this region are governed by a complex interplay between the Australasian monsoons and the ENSO system forced by changing insolation, sea level, ice sheets, and greenhouse gas concentrations. Existing reconstructions suggest heterogeneous responses of Indonesian climate to these forcings, highlighting the need for new long records of regional hydrology. We have developed multiproxy datasets from Lake Towuti and nearby lakes that provide continuous, detailed, and reproducible paleoenvironmental records spanning the past 60 kyr BP. Elemental tracers of terrestrial runoff and compound-specific stable isotope records of vegetation show that wet conditions and rainforest ecosystems persisted during Marine Isotope Stage 3 and the Holocene, and were interrupted by severe drying between 33 and 15 kyr BP when high-latitude ice sheets expanded and global temperatures cooled. This chronology of change implies that central Indonesian hydroclimate varies strongly in response to high-latitude climate forcing. New vegetation records from nearby lakes confirm these findings, but suggest the amplitude of glacial-interglacial changes in vegetation were weaker at high altitude, with important implications for the heterogeneity among Indonesian climate reconstructions. New lithologic and trace element records from Lake Towuti further document the significance of climate changes at the MIS3, 2, and 1 boundaries to Lake Towuti's paleolimnology, heat budget, and seasonal mixing. High-resolution seismic reflection data from Lake Towuti constrain the maximum depth of lake level lowstands during MIS2. Hydrological modeling suggests that precipitation was reduced by at least 50% at that time, an amplitude at or above the upper limits of precipitation changes

  1. A role for land surface forcing of North Atlantic climate and isotope signals during the 8.2kyr event?

    NASA Astrophysics Data System (ADS)

    Hopcroft, Peter; Valdes, Paul

    2014-05-01

    An important example of abrupt climate change occurred 8200 years ago in the North Atlantic and is generally known as the 8.2kyr event. This abrupt ~160 year cooling appears to coincide with the final drainage of the ice-dammed Lakes Agassiz and Ojibway. The resultant influx of meltwater to the North Atlantic is assumed to have perturbed the Atlantic Meridional Overturning circulation, reducing northward heat transport and causing widespread cooling. Numerous lines of evidence support this theory, with reconstructions showing changes in deep water formation, reductions in salinity and evidence of sea-level rise. Coupled general circulation model (GCM) simulations driven with realistic estimates of the meltwater flux show a regional cooling but fail to replicate the duration or the magnitude of this event in comparison with proxy archives. Meltwater injection was not the only rapid climate forcing in operation at this time. Drainage of the pro-glacial lakes would have had a profound effect on the boundary layer heat fluxes over North America, with potential teleconnections further afield. In this work we use an isotope-enabled version of the coupled GCM HadCM3 with boundary conditions appropriate for the time period of 9kyr (including ice sheets, greenhouse gases and orbital parameters). This model tracks oxygen isotopes throughout the hydrological cycle allowing more robust comparison with proxy archives. We analyse the impact of the removal of a lake area corresponding to Lakes Agassiz and Ojibway at this time and present sensitivity tests designed to analyse the contributions from lake removal, orographic change and the assumed isotopic content of the pro-glacial lakes. The results show a distinct pattern of cooling across North America (in the annual mean) with an apparent teleconnection to the Barents Sea, where there is warming associated with sea-ice reduction. The isotopic implications depend on the initial isotopic content of the pro-glacial lake. Assuming

  2. Sedimentary patterns on Cape Ghir margin (Morocco) during the past 30 kyr deciphered by their magnetic and geochemical properties

    NASA Astrophysics Data System (ADS)

    Blanchet, C.; Broder, T.; Goldhammer, T.; Freudenthal, T.; Stuut, J.-B.

    2009-04-01

    The sediments deposited on the Cape Ghir margin (Morocco) contain detailed records of Holocene oceanic and climatic regimes. Based on these results, the newly designed drill-rig MeBO has retrieved two pushed-cores on the continental margin (R.V. Maria S. Merian, 2007): cores GeoB11804 (355 m water depth) and GeoB11807 (908 m water depth). Since this corer allows deeper penetration in the sequence, we can extent the paleo-record further back in time. Also, the sedimentation in this region is known to be greatly fed by aeolian dust which can be traced using the magnetic properties of sediments, and eventually compared to the upwelling activity. A set of 26 calibrated 14C ages show that core GeoB11804 covers the last 30 kyr. Correlation of magnetic susceptibility profiles and ^18O measurements on planktonic foraminifers indicate that core GeoB11807 spans the last 20 kyr. Both cores exhibit mean sedimentation rates of ~110 cm/ka, therefore providing a time resolution of ~20 years. Very low terrigenous and magnetic contents are recorded between 30 and 18 ka, indicating the predominance of marine input on the margin during the Last Glacial Maximum (25-20 ka). The deglaciation is marked by pulses of magnetite (Fe3O4) and greigite (Fe3S4) at 18 and 12 ka, probably related to rapid sea level rises. These pulses are superimposed on a steady increase in terrigenous and magnetic contents between 18 and 10 ka, which could indicate a progressively stronger terrigenous contribution (from winds or rivers) due to sea level rise and/or climatic change. The Younger Dryas event (YD, 12-11 ka) is here recorded as an abrupt decrease in terrigenous sediment delivery. The hematite (Fe2S3) and goethite (FeOOH) contents rapidly and step-wisely increase after the YD and stabilize at ~ 8 ka. At ~ 1.7 ka, the magnetic contents abruptly increase, which might be related to diagenetic processes around the Sulfate-Methane transition. The top 1500 yrs are enriched in magnetic minerals of rather low

  3. Quantitative woody cover reconstructions from eastern continental Asia of the last 22 kyr reveal strong regional peculiarities

    NASA Astrophysics Data System (ADS)

    Tian, Fang; Cao, Xianyong; Dallmeyer, Anne; Ni, Jian; Zhao, Yan; Wang, Yongbo; Herzschuh, Ulrike

    2016-04-01

    We present a calibration-set based on modern pollen and satellite-based Advanced Very High Resolution Radiometer (AVHRR) observations of woody cover (including needleleaved, broadleaved and total tree cover) in eastern continental Asia, which shows good performance under cross-validation with the modern analogue technique (all the coefficients of determination between observed and predicted values are greater than 0.65). The calibration-set is used to reconstruct woody cover from a taxonomically harmonized and temporally standardized fossil pollen dataset (including 274 cores) with 500-year resolution over the last 22 kyr. The spatial range of forest has not noticeably changed in eastern continental Asia during the last 22 kyr, although woody cover has, especially at the margin of the eastern Tibetan Plateau and in the forest-steppe transition area of north-central China. Vegetation was sparse during the LGM in the present forested regions, but woody cover increased markedly at the beginning of the Bølling/Allerød period (B/A; ca. 14.5 ka BP) and again at the beginning of the Holocene (ca. 11.5 ka BP), and is related to the enhanced strength of the East Asian Summer Monsoon. Forest flourished in the mid-Holocene (ca. 8 ka BP) possibly due to favourable climatic conditions. In contrast, cover was stable in southern China (high cover) and arid central Asia (very low cover) throughout the investigated period. Forest cover increased in the north-eastern part of China during the Holocene. Comparisons of these regional pollen-based results with simulated forest cover from runs of a global climate model (for 9, 6 and 0 ka BP (ECHAM5/JSBACH ∼1.125° spatial resolution)) reveal many similarities in temporal change. The Holocene woody cover history of eastern continental Asia is different from that of other regions, likely controlled by different climatic variables, i.e. moisture in eastern continental Asia; temperature in northern Eurasia and North America.

  4. Multiproxy approach revealing climate and cultural changes during the last 26kyrs in south-central Chile

    NASA Astrophysics Data System (ADS)

    Abarzua, Ana M.; Jarpa, Leonora; Martel, Alejandra; Vega, Rodrigo; Pino, Mario

    2010-05-01

    Multiproxy approach from Purén Lumaco Valley (38°S) describes the paleonvironmental history during the Last Maximum Glacial (LGM) in south-central Chile. Three sediment cores and severals AMS 14C dates were used to perform a complete pollen, diatoms, chironomids, and sedimentological records demonstrating the existence of a large and non profundal paleolake, between 25 and 20kyr BP. Some of these evidence are laminated silty-clay sediments (lacustrine rhythmites), associated with the presence of siderite mineral (FeCO3), besides biological proxies like Fragilaria construens and Stauroforma inermes (planctonic diatoms), and Dicrotendipes sp. and Tanytarsini tribe (littoral chironomids). The pollen ensemble reveals the first glacial refuge of Araucaria araucana forests in the low lands during the LGM. The lake was drained abruptly into a swamp/bog at 12kyr BP and colonized by Myrtaceae wet forest. This evidence suggest the dry/warm climate period of early Holocene in south-central Chile. Later, the sediments indicate variable lacustrine levels, and increase of charcoal particles, associated to current climatic conditions. The pollen spectrum dominated by Myrtaceae and Nothofagus contrasts with a strongly disturb current landscape. Actually, Purén-Lumaco valley constitutes a complex peat-bog system dominated by exotic grasses and forest species (Tritricum aestivum, Pinus radiata and Eucalyptus spp.). Some archaeological antecedents in the area document the human development at ca. 7yrs BP. The greatest archaeological characteristic present in the valley is the kuel, a Mapuche earth accumulation. The presence and extension of almost 300 kuel in the valley reflect the social/economic development, and partly explains why the region was the major resistance area for Spanish colonizer during XVI-XVII centuries. Also the archaeological findings reveal the presence of maize pollen (Zea mays) within their food consumption. The influence of climate and human impact in

  5. Plant wax δD values record changing Eastern Mediterranean atmospheric circulation patterns during the 8.2 kyr B.P. climatic event

    NASA Astrophysics Data System (ADS)

    Schemmel, Fabian; Niedermeyer, Eva M.; Schwab, Valérie F.; Gleixner, Gerd; Pross, Jörg; Mulch, Andreas

    2016-02-01

    Throughout the Holocene, the climate of the Mediterranean region has been strongly influenced by variability in the atmospheric circulation of the high and low latitudes. A prominent example for such Holocene climate perturbations is the '8.2 kyr B.P. climatic event'. Reorganization of Northern Hemisphere atmospheric circulation patterns resulted in variations of temperature and precipitation distribution across the Mediterranean. The effects of changing high- and low-latitude atmospheric circulation on Mediterranean climate in relation to the 8.2 kyr B.P. climatic event are, however, not well understood. Here we present a high-resolution record of stable hydrogen isotope composition of plant-wax n-alkanes (δDwax) across the 8.2 kyr B.P. climatic event from the Tenaghi Philippon peat deposit (NE Greece) in order to characterize patterns of precipitation and changes in atmospheric circulation in the Eastern Mediterranean region. Our record reveals pronounced changes in δDwax that correlate closely with previously published palynological data. A long-term decline in δDwax values characterizes the lower part of the section. The 8.2 kyr B.P. climatic event itself is connected to two distinct positive δDwax excursions: a minor shift in δDwax around 8.2 kyr B.P. and a major shift in δDwax between ca. 8.1 and 8.0 kyr B.P.. The upper part of the section shows a progressive trend towards higher δDwax values. We link shifts in δDwax to changes in Mediterranean air mass trajectories supplying precipitation to NE Greece caused by variations in the relative contributions of northerly-derived, D-depleted moisture and southerly-derived, D-enriched moisture. Possible control mechanisms for alternating air mass trajectories include changes in the influence of the Siberian High and differences in the influence of the African and Asian monsoon circulation on anticyclonic conditions in the Mediterranean region as well as regional inflow of moist air masses from the Aegean Sea.

  6. Later endogenous circadian temperature nadir relative to an earlier wake time in older people

    NASA Technical Reports Server (NTRS)

    Duffy, J. F.; Dijk, D. J.; Klerman, E. B.; Czeisler, C. A.

    1998-01-01

    The contribution of the circadian timing system to the age-related advance of sleep-wake timing was investigated in two experiments. In a constant routine protocol, we found that the average wake time and endogenous circadian phase of 44 older subjects were earlier than that of 101 young men. However, the earlier circadian phase of the older subjects actually occurred later relative to their habitual wake time than it did in young men. These results indicate that an age-related advance of circadian phase cannot fully account for the high prevalence of early morning awakening in healthy older people. In a second study, 13 older subjects and 10 young men were scheduled to a 28-h day, such that they were scheduled to sleep at many circadian phases. Self-reported awakening from scheduled sleep episodes and cognitive throughput during the second half of the wake episode varied markedly as a function of circadian phase in both groups. The rising phase of both rhythms was advanced in the older subjects, suggesting an age-related change in the circadian regulation of sleep-wake propensity. We hypothesize that under entrained conditions, these age-related changes in the relationship between circadian phase and wake time are likely associated with self-selected light exposure at an earlier circadian phase. This earlier exposure to light could account for the earlier clock hour to which the endogenous circadian pacemaker is entrained in older people and thereby further increase their propensity to awaken at an even earlier time.

  7. A paleomagnetic and relative paleointensity record from the Argentine Basin (western South Atlantic Ocean) for the last ~125 kyrs

    NASA Astrophysics Data System (ADS)

    Heil, C. W., Jr.; Stoner, J. S.; St-Onge, G.; King, J. W.

    2015-12-01

    The paucity of paleomagnetic records from the western South Atlantic Ocean presents a significant gap in our understanding of the spatial variations in geomagnetic field dynamics as they relate to the occurrence of geomagnetic excursions and changes in field strength. As such, high quality records from this region can help build upon Holocene observations and extend the geographic and temporal data coverage for spherical harmonic models. To that end, we present paleomagnetic directional (inclination) and strength (relative paleointensity) records from two cores from the Argentine Basin (RC11-49 and RC16-88). Although the cores were collected more than 40 years ago, the sediments appear to hold a stable remanence and reliable magnetic directions, as evidenced by their reproducibility between the two cores that are separated by ~25 km. The records show evidence of 4 excursional features in the uppermost 16-m of the sediments from the basin. A comparison of the relative paleointensity records from these cores to the South Atlantic Paleointensity Stack (SAPIS) (Stoner et al., 2002) and the relative paleointensity record from ODP Site 1089 (Stoner et al., 2003) indicate that the sediments reliably record relative changes in geomagnetic field intensity and suggests that the longest record (RC11-49) spans the last ~125 kyrs. Our results indicate that the sediments of the Argentine Basin are an important sedimentary archive of geomagnetic field behavior and strength at least through the Holocene and Late Pleistocene and highlight the need for further studies of cores within the basin.

  8. Export production in the subarctic North Pacific over the last 800 kyrs: No evidence for iron fertilization?

    USGS Publications Warehouse

    Kienast, S.S.; Hendy, I.L.; Crusius, J.; Pedersen, Thomas F.; Calvert, S.E.

    2004-01-01

    The subarctic North Pacific is a high nitrate-low chlorophyll (HNLC) region, where phytoplankton growth rates, especially those of diatoms, are enhanced when micro-nutrient Fe is added. Accordingly, it has been suggested that glacial Fe-laden dust might have increased primary production in this region. This paper reviews published palaeoceanographic records of export production over the last 800 kyrs from the open North Pacific (north of ???35??N). We find different patterns of export production change over time in the various domains of the North Pacific (NW and NE subarctic gyres, the marginal seas and the transition zone). However, there is no compelling evidence for an overall increase in productivity during glacials in the subarctic region, challenging the paradigm that dust-born Fe fertilization of this region has contributed to the glacial draw down of atmospheric CO2. Potential reasons for the lack of increased glacial export production include the possibility that Fe-fertilization rapidly drives the ecosystem towards limitation by another nutrient. This effect would have been exacerbated by an even more stable mixed layer compared to today. ?? The Oceanographic Society of Japan.

  9. The bioavailable iron in NEEM ice core related to Asian dust records over the past 110 kyr

    NASA Astrophysics Data System (ADS)

    Xiao, Cunde

    2016-04-01

    The mineral dust can indirectly affect climate by supplying iron and other essential bioavailable elements into ocean. In this study, we present dissolved iron (DFe) and total dissolved iron (TDFe) concentrations in NEEM ice core over the past 110 kyr B.P. The concentrations of bioavailable reactive element Fe have good positive correlation with the concentrations of dust and Ca2+ in NEEM ice core, while show significantly negative relationship with δ18O and CO2 concentration. The ratios of DFe/TDFe are higher in warm periods (Holocene and last interglacial) than in cold period (LGM), indicating the iron-biological pump effect is more significant in warm periods than that in cold periods, this result may provide a new insight for reevaluating the iron hypothesis over glacial/interglacial periods. Our study also shows that the iron flux changes between NEEM ice core and Asian loess records are good consistent with the northern Hemisphere summer insolation. These results emphasize that the variability of Fe flux is most likely driven by solar radiation and dust in northern hemisphere.

  10. Thermal isolation of Campbell Plateau, New Zealand, by the Antarctic Circumpolar Current over the past 130 kyr

    NASA Astrophysics Data System (ADS)

    Neil, Helen L.; Carter, Lionel; Morris, Michele Y.

    2004-12-01

    Campbell Plateau occupies a key position in the southwest Pacific sector of the Southern Ocean. The plateau confines and steers the Antarctic Circumpolar Current (ACC) along its flanks, isolating the Subantarctic plateau from cold polar waters. Oxygen and carbon isotope records from Campbell Plateau cores provide new records of water mass stratification for the past 130 kyr. During glacial climes, strengthening of the Subantarctic Front (SAF) caused waters over the plateau flanks to be deeply mixed and ˜3°C cooler. Waters of the plateau interior remained stratified and isolated from the cold southern waters. In the west, waters cooled markedly (˜4°C) owing to reduced entrainment of Tasman Sea water. Marked cooling also occurred north of Campbell Plateau under increased entrainment of polar water by a branch of the SAF. The ACC remained along the flanks of Campbell Plateau during the last interglacial, when interior waters were stratified and warmer by ˜1°C than now.

  11. Sea ice and millennial-scale climate variability in the Nordic seas 90 kyr ago to present.

    PubMed

    Hoff, Ulrike; Rasmussen, Tine L; Stein, Ruediger; Ezat, Mohamed M; Fahl, Kirsten

    2016-01-01

    In the light of rapidly diminishing sea ice cover in the Arctic during the present atmospheric warming, it is imperative to study the distribution of sea ice in the past in relation to rapid climate change. Here we focus on glacial millennial-scale climatic events (Dansgaard/Oeschger events) using the sea ice proxy IP25 in combination with phytoplankton proxy data and quantification of diatom species in a record from the southeast Norwegian Sea. We demonstrate that expansion and retreat of sea ice varies consistently in pace with the rapid climate changes 90 kyr ago to present. Sea ice retreats abruptly at the start of warm interstadials, but spreads rapidly during cooling phases of the interstadials and becomes near perennial and perennial during cold stadials and Heinrich events, respectively. Low-salinity surface water and the sea ice edge spreads to the Greenland-Scotland Ridge, and during the largest Heinrich events, probably far into the Atlantic Ocean. PMID:27456826

  12. Sea ice and millennial-scale climate variability in the Nordic seas 90 kyr ago to present

    PubMed Central

    Hoff, Ulrike; Rasmussen, Tine L.; Stein, Ruediger; Ezat, Mohamed M.; Fahl, Kirsten

    2016-01-01

    In the light of rapidly diminishing sea ice cover in the Arctic during the present atmospheric warming, it is imperative to study the distribution of sea ice in the past in relation to rapid climate change. Here we focus on glacial millennial-scale climatic events (Dansgaard/Oeschger events) using the sea ice proxy IP25 in combination with phytoplankton proxy data and quantification of diatom species in a record from the southeast Norwegian Sea. We demonstrate that expansion and retreat of sea ice varies consistently in pace with the rapid climate changes 90 kyr ago to present. Sea ice retreats abruptly at the start of warm interstadials, but spreads rapidly during cooling phases of the interstadials and becomes near perennial and perennial during cold stadials and Heinrich events, respectively. Low-salinity surface water and the sea ice edge spreads to the Greenland–Scotland Ridge, and during the largest Heinrich events, probably far into the Atlantic Ocean. PMID:27456826

  13. Ice-flow reorganization in West Antarctica 2.5 kyr ago dated using radar-derived englacial flow velocities

    NASA Astrophysics Data System (ADS)

    Kingslake, Jonathan; Martín, Carlos; Arthern, Robert J.; Corr, Hugh F. J.; King, Edward C.

    2016-09-01

    We date a recent ice-flow reorganization of an ice divide in the Weddell Sea Sector, West Antarctica, using a novel combination of inverse methods and ice-penetrating radars. We invert for two-dimensional ice flow within an ice divide from data collected with a phase-sensitive ice-penetrating radar while accounting for the effect of firn on radar propagation and ice flow. By comparing isochronal layers simulated using radar-derived flow velocities with internal layers observed with an impulse radar, we show that the divide's internal structure is not in a steady state but underwent a disturbance, potentially implying a regional ice-flow reorganization, 2.5 (1.8-2.9) kyr B.P. Our data are consistent with slow ice flow in this location before the reorganization and the ice divide subsequently remaining stationary. These findings increase our knowledge of the glacial history of a region that lacks dated constraints on late-Holocene ice-sheet retreat and provides a key target for models that reconstruct and predict ice-sheet behavior.

  14. Palaeomagnetic intensities from 14C-dated lava flows on the Big Island, Hawaii: 0-21 kyr

    USGS Publications Warehouse

    Pressling, Nicola; Laj, Carlo; Kissel, Catherie; Champion, Duane E.; Gubbins, David

    2006-01-01

    Thellier–Thellier experiments were carried out on 216 lava samples collected by the USGS on the Big Island. 35 individual flows from the Kilauea, Mauna Loa and Hualalai volcanoes are represented and independent radiocarbon dating of the flows yields absolute ages ranging from 290 to 20,240 yrs old. The palaeomagnetic analysis was carried out at the Laboratoire des Sciences du Climat et de l'Environnement in Gif-sur-Yvette, France, in two custom built, large capacity furnaces that have been specifically designed to minimise oxidation. The temperature steps were adapted to accommodate the characteristic loss of magnetisation at low temperatures seen in the Curie balance results and the use of half-size samples allowed secondary experiments to be carried out where necessary. The strict PICRIT-03 selection criteria were rigorously applied to the data and a high success rate of 53% has been achieved on a sample level. The flow averaged results almost double the existing 14C-dated palaeointensity dataset for this time window and confirm a period of high intensity over the past 4 kyr preceded by a period in which the dipole moment was weaker. However, the values attained in this study are on average higher than previously published data; reliability of these values is discussed.

  15. Winter Anomaly 1982/83 in Comparison with Earlier Winters (1960-82)

    NASA Technical Reports Server (NTRS)

    Lastovicka, J.

    1984-01-01

    The winter anomaly in the winter of 1982/83 is compared with the winter anomalies of earlier winters (1960-82) from the point of view of amplitude and timing of the winter anomaly, and geomagnetic and dynamic activity influences. Some evidence of a negative influence of sudden stratospheric warnings on the winter anomaly is given.

  16. Left ventricular pseudoaneurysm found after mitral valve replacement performed 30 years earlier.

    PubMed

    Castilla, Elena; Gato, Manuel; Ruiz, José Ramón

    2010-03-01

    Pseudoaneurysm of the left ventricle (LV) is a rare cardiac disease that occurs after myocardial infarction or cardiac surgery. Because patients frequently present with nonspecific symptoms, a high index of suspicion is needed to make the diagnosis. This report describes an unusual case demonstrating a large LV pseudoaneurysm after mitral valve replacement performed 30 years earlier. PMID:20197588

  17. Children Learning to Read Later Catch up to Children Reading Earlier

    ERIC Educational Resources Information Center

    Suggate, Sebastian P.; Schaughency, Elizabeth A.; Reese, Elaine

    2013-01-01

    Two studies from English-speaking samples investigated the methodologically difficult question of whether the later reading achievement of children learning to read earlier or later differs. Children (n = 287) from predominantly state-funded schools were selected and they differed in whether the reading instruction age (RIA) was either five or…

  18. Late Quaternary vegetation and environments in the Verkhoyansk Mountains region (NE Asia) reconstructed from a 50-kyr fossil pollen record from Lake Billyakh

    NASA Astrophysics Data System (ADS)

    Müller, Stefanie; Tarasov, Pavel E.; Andreev, Andrei A.; Tütken, Thomas; Gartz, Steffi; Diekmann, Bernhard

    2010-08-01

    Here we present a detailed radiocarbon-dated 936 cm long pollen record from Lake Billyakh (65°17'N, 126°47'E; 340 m a.s.l.) situated in the western part of the Verkhoyansk Mountains, about 140 km south of the Arctic Circle. A set of 53 surface pollen samples representing tundra, cold deciduous forest and taiga was collected in northern and central Yakutia communities to verify the accuracy of the quantitative biome reconstruction method and to obtain a more precise attribution of the identified pollen taxa to the main regional biomes. The adjusted method is then applied to the pollen record from Lake Billyakh to gain a reconstruction of vegetation and environments since about 50.7 kyr BP. The results of the pollen analysis and pollen-based biome reconstruction suggest that herbaceous tundra and steppe communities dominated the area from 50.7 to 13.5 kyr BP. Relatively low pollen concentrations and high percentages of herbaceous pollen taxa (mainly Cyperaceae, Poaceae and Artemisia) likely indicate a reduced vegetation cover and/or lower pollen production. On the other hand, extremely low percentages of drought-tolerant taxa, such as Chenopodiaceae and Ephedra, and the constant presence of various mesophyllous herbaceous ( Thalictrum, Rosaceae, Asteraceae) and shrubby taxa ( Betula sect. Nanae/Fruticosae, Duschekia fruticosa, Salix) in the pollen assemblages prevent an interpretation of the last glacial environments around Lake Billyakh as extremely arid. The lowest pollen percentages of woody taxa and the highest values of Artemisia pollen attest that the 31-15 kyr BP period as the driest and coldest interval of the entire record. A relative high content of taxa representing shrub tundra communities and the presence of larch pollen recorded prior to 31 kyr and after 13.5 kyr BP likely indicate interstadial climate amelioration associated with the middle and latest parts of the last glacial. An increase in pollen percentages of herbaceous taxa around 12 kyr BP

  19. A Coral Based Reconstruction of Atmospheric Δ14C through the Mystery Interval (17.5 to 14.5 kyr BP)

    NASA Astrophysics Data System (ADS)

    Mortlock, R. A.; Abdul, N. A.; Wright, J. D.; Fairbanks, R. G.; Cao, L.

    2011-12-01

    Reconstructions of atmospheric Δ14C from various archives (speleothems, planktic foraminifera, surface corals) record a ~ 190 per mil (%) decrease in Δ14C during the Mystery Interval (17.5 to 14.5 kyr BP). It has been suggested that the decrease results from the injection of 14C depleted waters during the deglacial. Supporting evidence comes from benthic forams in sediment cores off Baja, CA that record a 300% decrease in the 14C content of intermediate waters at the same time ice core records display an increase in atmospheric CO2. Records of opal burial in Southern Ocean sediments suggest increased upwelling (and release of 14C depleted CO2 to the atmosphere) during the Mystery Interval. We have updated our previously published record of atmospheric Δ14C with an additional 60-paired radiocarbon and U-series dated surface corals. A unique advantage to using the fossil coral archive is that both radiocarbon and calendar ages can be obtained from the same sample, whereas atmospheric 14C reconstructions generated from deep sea core microfossils require assigned calendar ages which are based on proxies correlated to ice cores and are subject to proxy interpretations, correlation errors, and uncertainties in ice core chronologies. Unfortunately small inaccuracies in the estimated calendar ages lead to large Δ14C errors. The updated coral record adds considerable coverage to both the Mystery Interval (previously constrained by coral data only at the boundaries in INTCAL04 and 09), and for the time period 26 to 18 kyr BP. Our record permits a better estimate as to the timing, duration, and magnitude of the decrease in Δ14C during the Mystery Interval. We observe a break in the declining 27 to 21 kyr BP trend of Δ14C at about 20 kyr BP. From 20 to 18.5 kyr BP Δ14C increases by about 100% to a maximum value of about 430%. Δ14C decreases to 300% by about 17 kyr BP at which time the long term declining trend in Δ14C is re-established and continues throughout the

  20. Sediment Cd and Mo accumulation in the oxygen-minimum zone off western Baja California linked to global climate over the past 52 kyr

    USGS Publications Warehouse

    Dean, W.E.; Zheng, Yen; Ortiz, J.D.; VanGeen, A.

    2006-01-01

    Concentrations of organic carbon (orgC), cadmium (Cd), and molybdenum (Mo) were measured in two sediment cores raised from depths of 430 and 700 m within the oxygen-minimum zone (OMZ) off southern Baja California at a temporal resolution of e10.5 kyr over the past 52 kyr. These records are supplemented with diffuse spectral reflectance (DSR) measurements obtained on board ship soon after collection at a resolution of e10.05 kyr. In the core from 700 m depth, a component extracted from the DSR data and the three geochemical proxies generally vary in concert with each other and over a wide range (4-22% orgC; 1-40 mg/kg Cd; 5-120 mg/kg Mo). Intervals of increased orgC, Cd, and Mo accumulation generally correspond to warm periods recorded in the oxygen-isotopic composition of Greenland ice, with the exception of the Bolling/Allerod which is only weakly expressed off Baja California. Concentrations of the biogenic proxies are higher in the core from 430 m depth, but erratic sediment accumulation before 15 ka precludes dating of the older intervals that are laminated and contain elevated orgC, Cd, and Mo concentrations. The new data provide further evidence of an intimate teleconnection between global climate and the intensity of the OMZ and/or productivity along the western margin of North America. On the basis of a comparison with Cd and Mo records collected elsewhere in the region, we conclude that productivity may actually have varied off southern Baja California by no more than a factor of 2 over the past 52 kyr. Copyright 2006 by the American Geophysical Union.

  1. Age-depth model of the past 630 kyr for Lake Ohrid (FYROM/Albania) based on cyclostratigraphic analysis of downhole gamma ray data

    NASA Astrophysics Data System (ADS)

    Baumgarten, H.; Wonik, T.; Tanner, D. C.; Francke, A.; Wagner, B.; Zanchetta, G.; Sulpizio, R.; Giaccio, B.; Nomade, S.

    2015-12-01

    Gamma ray (GR) fluctuations and potassium (K) values from downhole logging data obtained in the sediments of Lake Ohrid from 0 to 240 m below lake floor (b.l.f). correlate with fluctuations in δ18O values from the global benthic isotope stack LR04 (Lisiecki and Raymo, 2005). GR and K values are considered a reliable proxy to depict glacial-interglacial cycles, with high clastic input during cold and/or drier periods and high carbonate precipitation during warm and/or humid periods at Lake Ohrid. Spectral analysis was applied to investigate the climate signal and evolution over the length of the borehole. Linking downhole logging data with orbital cycles was used to estimate sedimentation rates and the effect of compaction was compensated for. Sedimentation rates increase on average by 14 % after decompaction of the sediment layers and the mean sedimentation rates shift from 45 cm kyr-1 between 0 and 110 m to 30 cm kyr-1 from 110 to 240 m b.l.f. Tuning of minima and maxima of gamma ray and potassium values versus LR04 extrema, in combination with eight independent tephrostratigraphical tie points, allows establishing of a robust age model for the downhole logging data over the past 630 kyr.

  2. Predictors of Revision Surgery After Primary Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Yabroudi, Mohammad A.; Björnsson, Haukur; Lynch, Andrew D.; Muller, Bart; Samuelsson, Kristian; Tarabichi, Majd; Karlsson, Jón; Fu, Freddie H.; Harner, Christopher D.; Irrgang, James J.

    2016-01-01

    Background: Revision anterior cruciate ligament (ACL) reconstruction surgery occurs in 5% to 15% of individuals undergoing ACL reconstruction. Identifying predictors for revision ACL surgery is of essence in the pursuit of creating adequate prevention programs and to identify individuals at risk for reinjury and revision. Purpose: To determine predictors of revision ACL surgery after failed primary ACL reconstruction. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 251 participants (mean age ± SD, 26.1 ± 9.9 years) who had undergone primary ACL reconstruction 1 to 5 years earlier completed a comprehensive survey to determine predictors of revision ACL surgery at a mean 3.4 ± 1.3 years after the primary ACL reconstruction. Potential predictors that were assessed included subject characteristics (age at the time of surgery, time from injury to surgery, sex, body mass index, preinjury activity level, return to sport status), details of the initial injury (mechanism; concomitant injury to other ligaments, menisci, and cartilage), surgical details of the primary reconstruction (Lachman and pivot shift tests under anesthesia, graft type, femoral drilling technique, reconstruction technique), and postoperative course (length of rehabilitation, complications). Univariate and multivariate logistic regression analyses were performed to identify factors that predicted the need for revision ACL surgery. Results: Overall, 21 (8.4%) subjects underwent revision ACL surgery. Univariate analysis showed that younger age at the time of surgery (P = .003), participation in sports at a competitive level (P = .023), and double-bundle ACL reconstruction (P = .024) predicted increased risk of revision ACL surgery. Allograft reconstructions also demonstrated a trend toward greater risk of revision ACL surgery (P = .076). No other variables were significantly associated with revision ACL surgery. Multivariate analysis revealed that revision ACL surgery was

  3. Scar revision - series (image)

    MedlinePlus

    Surgery to revise scars is done while the patient is awake, sleeping (sedated), or deep asleep and pain-free (local anesthesia or general anesthesia). Massive injuries (such as burns) can cause loss of a large area of ...

  4. Observed shift towards earlier spring discharge in the main Alpine rivers.

    PubMed

    Zampieri, Matteo; Scoccimarro, Enrico; Gualdi, Silvio; Navarra, Antonio

    2015-01-15

    In this study, we analyse the observed long-term discharge time-series of the Rhine, the Danube, the Rhone and the Po rivers. These rivers are characterised by different seasonal cycles reflecting the diverse climates and morphologies of the Alpine basins. However, despite the intensive and varied water management adopted in the four basins, we found common features in the trend and low-frequency variability of the spring discharge timings. All the discharge time-series display a tendency towards earlier spring peaks of more than two weeks per century. These results can be explained in terms of snowmelt, total precipitation (i.e. the sum of snowfall and rainfall) and rainfall variability. The relative importance of these factors might be different in each basin. However, we show that the change of seasonality of total precipitation plays a major role in the earlier spring runoff over most of the Alps.

  5. A vantage from space can detect earlier drought onset: an approach using relative humidity.

    PubMed

    Farahmand, Alireza; AghaKouchak, Amir; Teixeira, Joao

    2015-01-01

    Each year, droughts cause significant economic and agricultural losses across the world. The early warning and onset detection of drought is of particular importance for effective agriculture and water resource management. Previous studies show that the Standard Precipitation Index (SPI), a measure of precipitation deficit, detects drought onset earlier than other indicators. Here we show that satellite-based near surface air relative humidity data can further improve drought onset detection and early warning. This paper introduces the Standardized Relative Humidity Index (SRHI) based on the NASA Atmospheric Infrared Sounder (AIRS) observations. The results indicate that the SRHI typically detects the drought onset earlier than the SPI. While the AIRS mission was not originally designed for drought monitoring, we show that its relative humidity data offers a new and unique avenue for drought monitoring and early warning. We conclude that the early warning aspects of SRHI may have merit for integration into current drought monitoring systems. PMID:25711500

  6. Compulsive buying: Earlier illicit drug use, impulse buying, depression, and adult ADHD symptoms.

    PubMed

    Brook, Judith S; Zhang, Chenshu; Brook, David W; Leukefeld, Carl G

    2015-08-30

    This longitudinal study examined the association between psychosocial antecedents, including illicit drug use, and adult compulsive buying (CB) across a 29-year time period from mean age 14 to mean age 43. Participants originally came from a community-based random sample of residents in two upstate New York counties. Multivariate linear regression analysis was used to study the relationship between the participant's earlier psychosocial antecedents and adult CB in the fifth decade of life. The results of the multivariate linear regression analyses showed that gender (female), earlier adult impulse buying (IB), depressive mood, illicit drug use, and concurrent ADHD symptoms were all significantly associated with adult CB at mean age 43. It is important that clinicians treating CB in adults should consider the role of drug use, symptoms of ADHD, IB, depression, and family factors in CB.

  7. Compulsive Buying: Earlier Illicit Drug Use, Impulse Buying, Depression, and Adult ADHD Symptoms

    PubMed Central

    Brook, Judith S.; Zhang, Chenshu; Brook, David W.; Leukefeld, Carl G.

    2015-01-01

    This longitudinal study examined the association between psychosocial antecedents, including illicit drug use, and adult compulsive buying (CB) across a 29-year time period from mean age 14 to mean age 43. Participants originally came from a community-based random sample of residents in two upstate New York counties. Multivariate linear regression analysis was used to study the relationship between the participant’s earlier psychosocial antecedents and adult CB in the fifth decade of life. The results of the multivariate linear regression analyses showed that gender (female), earlier adult impulse buying (IB), depressive mood, illicit drug use, and concurrent ADHD symptoms were all significantly associated with adult CB at mean age 43. It is important that clinicians treating CB in adults should consider the role of drug use, symptoms of ADHD, IB, depression, and family factors in CB. PMID:26165963

  8. Bottom water variability in the subtropical northwestern Pacific from 26 kyr BP to present based on Mg / Ca and stable carbon and oxygen isotopes of benthic foraminifera

    NASA Astrophysics Data System (ADS)

    Kubota, Y.; Kimoto, K.; Itaki, T.; Yokoyama, Y.; Miyairi, Y.; Matsuzaki, H.

    2015-06-01

    To understand bottom water variability in the subtropical northwestern Pacific, bottom water temperatures (BWTs), carbon isotopes (δ13C), and oxygen isotopes of seawater (δ18Ow) at a water depth of 1166 m were reconstructed from 26 kyr BP to present. A new regional Mg / Ca calibration for the benthic foraminifera Cibicidoides wuellerstorfi (type B) was established to convert the benthic Mg / Ca value to BWT, based on 26 surface sediment samples and two core-top samples retrieved around Okinawa Island. During the Last Glacial Maximum (LGM), the δ18Ow in the intermediate water in the northwestern South Pacific was ~0.4‰ lower than in the deep South Pacific, indicating a greater vertical salinity gradient than at present. This salinity (and probably density) structure would have led to stratification in the intermediate and deep Pacific, which would, in turn, have greatly influenced carbon storage during the glacial time. The benthic Mg / Ca and δ18Ow records suggest changes that seem to follow Heinrich event 1 (H1) and the Bølling-Alleød (B/A) and Younger Dryas (YD) intervals, with BWT higher during H1 (~17 kyr BP) and YD (~12 kyr BP) and lower during B/A (~14 kyr BP). The warming in the bottom water during H1 suggests increased contribution of North Pacific Intermediate Water (NPIW) to the subtropical northwestern Pacific and decreased upwelling of cooler waters from the abyssal North Pacific. During the interval from 17 to 14.5 kyr BP, the BWT tended to decrease successively in association with a decrease in δ13C values, presumably as a result of increased upwelling of the abyssal waters to the intermediate depths of the North Pacific caused by shoaling and enhancement of the southward return flow of Pacific Deep Water (PDW). During the Holocene, the millennial- to sub-millennial-scale variations in the BWT generally correlate with the sea surface temperatures in the Okhotsk Sea, the source region of the NPIW, suggesting that changes in the BWT are linked

  9. Thermal Control Materials on MISSE-6 with Comparison to Earlier Flight Data

    NASA Technical Reports Server (NTRS)

    Finckenor, Miria M.; Zwiener, James M.; Alvis, Amy; Jones, Steve; Jones, Ken

    2010-01-01

    This slide presentation reviews the results of exposing thermal control materials as studied during Materials International Space Station Experiment-6 (MISSE-6). It discusses the location of the materials, and the type of environmental exposure. It then reviews the effect on the various types of coatings, showing the results with graphs and photos of the samples after the experimental exposure to the low earth orbital environment for comparison with the control sample and with earlier flights.

  10. A Review of Quality of Life after Predictive Testing for and Earlier Identification of Neurodegenerative Diseases

    PubMed Central

    Paulsen, Jane S.; Nance, Martha; Kim, Ji-In; Carlozzi, Noelle E.; Panegyres, Peter K.; Erwin, Cheryl; Goh, Anita; McCusker, Elizabeth; Williams, Janet K.

    2013-01-01

    The past decade has witnessed an explosion of evidence suggesting that many neurodegenerative diseases can be detected years, if not decades, earlier than previously thought. To date, these scientific advances have not provoked any parallel translational or clinical improvements. There is an urgency to capitalize on this momentum so earlier detection of disease can be more readily translated into improved health-related quality of life for families at risk for, or suffering with, neurodegenerative diseases. In this review, we discuss health-related quality of life (HRQOL) measurement in neurodegenerative diseases and the importance of these “patient reported outcomes” for all clinical research. Next, we address HRQOL following early identification or predictive genetic testing in some neurodegenerative diseases: Huntington disease, Alzheimer's disease, Parkinson's disease, Dementia with Lewy bodies, frontotemporal dementia, amyotrophic lateral sclerosis, prion diseases, hereditary ataxias, Dentatorubral-pallidoluysian atrophy and Wilson's disease. After a brief report of available direct-to-consumer genetic tests, we address the juxtaposition of earlier disease identification with assumed reluctance towards predictive genetic testing. Forty-one studies examining health related outcomes following predictive genetic testing for neurodegenerative disease suggested that (a) extreme or catastrophic outcomes are rare; (b) consequences commonly include transiently increased anxiety and/or depression; (c) most participants report no regret; (d) many persons report extensive benefits to receiving genetic information; and (e) stigmatization and discrimination for genetic diseases are poorly understood and policy and laws are needed. Caution is appropriate for earlier identification of neurodegenerative diseases but findings suggest further progress is safe, feasible and likely to advance clinical care. PMID:24036231

  11. A review of quality of life after predictive testing for and earlier identification of neurodegenerative diseases.

    PubMed

    Paulsen, Jane S; Nance, Martha; Kim, Ji-In; Carlozzi, Noelle E; Panegyres, Peter K; Erwin, Cheryl; Goh, Anita; McCusker, Elizabeth; Williams, Janet K

    2013-11-01

    The past decade has witnessed an explosion of evidence suggesting that many neurodegenerative diseases can be detected years, if not decades, earlier than previously thought. To date, these scientific advances have not provoked any parallel translational or clinical improvements. There is an urgency to capitalize on this momentum so earlier detection of disease can be more readily translated into improved health-related quality of life for families at risk for, or suffering with, neurodegenerative diseases. In this review, we discuss health-related quality of life (HRQOL) measurement in neurodegenerative diseases and the importance of these "patient reported outcomes" for all clinical research. Next, we address HRQOL following early identification or predictive genetic testing in some neurodegenerative diseases: Huntington disease, Alzheimer's disease, Parkinson's disease, Dementia with Lewy bodies, frontotemporal dementia, amyotrophic lateral sclerosis, prion diseases, hereditary ataxias, Dentatorubral-pallidoluysian atrophy and Wilson's disease. After a brief report of available direct-to-consumer genetic tests, we address the juxtaposition of earlier disease identification with assumed reluctance toward predictive genetic testing. Forty-one studies examining health-related outcomes following predictive genetic testing for neurodegenerative disease suggested that (a) extreme or catastrophic outcomes are rare; (b) consequences commonly include transiently increased anxiety and/or depression; (c) most participants report no regret; (d) many persons report extensive benefits to receiving genetic information; and (e) stigmatization and discrimination for genetic diseases are poorly understood and policy and laws are needed. Caution is appropriate for earlier identification of neurodegenerative diseases but findings suggest further progress is safe, feasible and likely to advance clinical care. PMID:24036231

  12. MRI evaluation of brain iron in earlier- and later-onset Parkinson's disease and normal subjects.

    PubMed

    Bartzokis, G; Cummings, J L; Markham, C H; Marmarelis, P Z; Treciokas, L J; Tishler, T A; Marder, S R; Mintz, J

    1999-02-01

    Tissue iron levels in the extrapyramidal system of earlier- and later-onset Parkinson's disease (PD) subjects were evaluated in vivo using a magnetic resonance imaging (MRI) method. The method involves scanning subjects in both high- and low-field MRI instruments, measuring tissue relaxation rate (R2), and calculating the field-dependent R2 increase (FDRI) which is the difference between the R2 measured with the two MRI instruments. In tissue, only ferritin iron is known to increase R2 in a field-dependent manner and the FDRI measure is a specific measure of this tissue iron pool. Two groups of male subjects with PD and two age-matched groups of normal control males were studied. The two groups of six subjects with PD consisted of subjects with earlier- or later-onset (before or after age 60) PD. FDRI was measured in five subcortical structures: the substantia nigra reticulata (SNR), substantia nigra compacta (SNC), globus pallidus, putamen, and caudate nucleus, and in one comparison region; the frontal white matter. Earlier-onset PD subjects had significant (p < 0.05) increases in FDRI in the SNR, SNC, putamen, and globus pallidus, while later-onset PD subjects had significantly decreased FDRI in the SNR when compared to their respective age-matched controls. Controlling for illness duration or structure size did not meaningfully alter the results. Published post-mortem studies on SN iron levels indicate decreased ferritin levels and increased free iron levels in the SN of older PD subjects, consistent with the decreased FDRI observed in our later-onset PD sample, which was closely matched in age to the post-mortem PD samples. The FDRI results suggest that disregulation of iron metabolism occurs in PD and that this disregulation may differ in earlier- versus later-onset PD. PMID:10215476

  13. Floodplains within reservoirs promote earlier spawning of white crappies Pomoxis annularis

    USGS Publications Warehouse

    Miranda, Leandro E.; Dagel, Jonah D.; Kaczka, Levi J.; Mower, Ethan; Wigen, S. L.

    2015-01-01

    Reservoirs impounded over floodplain rivers are unique because they may include within their upper reaches extensive shallow water stored over preexistent floodplains. Because of their relatively flat topography and riverine origin, floodplains in the upper reaches of reservoirs provide broad expanses of vegetation within a narrow range of reservoir water levels. Elsewhere in the reservoir, topography creates a band of shallow water along the contour of the reservoir where vegetation often does not grow. Thus, as water levels rise, floodplains may be the first vegetated habitats inundated within the reservoir. We hypothesized that shallow water in reservoir floodplains would attract spawning white crappies Pomoxis annularis earlier than reservoir embayments. Crappie relative abundance over five years in floodplains and embayments of four reservoirs increased as spawning season approached, peaked, and decreased as fish exited shallow water. Relative abundance peaked earlier in floodplains than embayments, and the difference was magnified with higher water levels. Early access to suitable spawning habitat promotes earlier spawning and may increase population fitness. Recognition of the importance of reservoir floodplains, an understanding of how reservoir water levels can be managed to provide timely connectivity to floodplains, and conservation of reservoir floodplains may be focal points of environmental management in reservoirs.

  14. Geochemical records from loess deposits in Japan over the last 210 kyr: Lithogenic source changes and paleoclimatic indications

    NASA Astrophysics Data System (ADS)

    Miyazaki, Takashi; Kimura, Jun-Ichi; Katakuse, Maiko

    2016-07-01

    The generation, transport, and accumulation of tropospheric dust have changed with the paleoclimatic changes of the Quaternary period. Such dust has accumulated in Japan ˜3000 km leeward of the source deserts in China. We analyzed the fractions of windblown fine quartz and bulk major and trace elements, and Sr-Nd-Pb isotopic compositions of loess in SW Japan deposited over the past 210 kyr. The results indicated extensive accumulation of tropospheric dust mixed with tephra fragments derived from the nearby Daisen volcano. The accumulation rate of fine quartz and selected elemental/isotopic compositions can be used as climatic proxies that reflect greater accumulation of dust in times of colder climate. Chemical indices for weathering show enhanced effects of weathering during times of warmer climate. The trace element compositions of the loess deposits are surprisingly similar to those of the Chinese loess, hemipelagic sediments in the Sea of Japan and the western Pacific Ocean, and the distal Chinese dust found in Canada. This similarity indicates that the loess dust shares major fractions of these fine-grained sediments and that geochemical fractionation during the transport was limited. The Sr-Nd-Pb isotope compositions of the SW Japan loess indicate an origin predominantly in the Gobi Desert. The high-latitude Pacific sediments and high-latitude dust in Canada also show the same signature. However, isotopic compositions of samples from the southern Chinese loess plateau and mid to low-latitude Pacific sediments are largely derived from the Taklimakan desert, which indicates different delivery pathways of the tropospheric dusts.

  15. Mindanao Dome variability over the last 160 kyr: Episodic glacial cooling of the West Pacific Warm Pool

    NASA Astrophysics Data System (ADS)

    Bolliet, Timothé; Holbourn, Ann; Kuhnt, Wolfgang; Laj, Carlo; Kissel, Catherine; Beaufort, Luc; Kienast, Markus; Andersen, Nils; Garbe-Schönberg, Dieter

    2011-02-01

    We present sea surface, upper thermocline, and benthic δ18O data, as well as temperature and paleoproductivity proxy data, from the International Marine Global Change Study Program (IMAGES) Core MD06-3067 (6°31‧N, 126°30‧E, 1575 m water depth), located in the western equatorial Pacific Ocean within the flow path of the Mindanao Current. Our records reveal considerable glacial-interglacial and suborbital variability in the Mindanao Dome upwelling over the last 160 kyr. Dome activity generally intensified during glacial intervals resulting in cooler thermocline waters, whereas it substantially declined during interglacials, in particular in the early Holocene and early marine oxygen isotope stage (MIS) 5e, when upwelling waters did not reach the thermocline. During MIS 3 and MIS 2, enhanced surface productivity together with remarkably low SST and low upper ocean thermal contrast provide evidence for episodic glacial upwelling to the surface, whereas transient surface warming marks periodic collapses of the Mindanao Dome upwelling during Heinrich events. We attribute the high variability during MIS 3 and MIS 2 to changes in the El Niño Southern Oscillation state that affected boreal winter monsoonal winds and upper ocean circulation. Glacial upwelling intensified when a strong cyclonic gyre became established, whereas El Niño-like conditions during Heinrich events tended to suppress the cyclonic circulation, reducing Ekman transport. Thus, our findings demonstrate that variations in the Mindanao Dome upwelling are closely linked to the position and intensity of the tropical convection and also reflect far-field influences from the high latitudes.

  16. Links between carbonate productivity and ENSO variability in the southern California Current System for the past 2 Kyrs

    NASA Astrophysics Data System (ADS)

    Abella-Gutiérrez, J. L.; Herguera, J. C.

    2014-12-01

    San Lázaro Basin (SLB) is a suboxic basin characteristic for its very high sedimentation rates (1mm/yr) and is located in the dynamic southern boundary of the California Current System (CCS). This southern boundary of the CCS generally extends further south during spring into early summer and retracts towards the north during fall and winter, and this pattern is further amplified or reduced on different time scales, (e.i. interannual timescales by El Niño and La Niña events, or multidecadal ones by the Pacific Decadal Oscillation (PDO)). These oceanographic conditions are related with important differences in the base of the food chain; when the boundary migrates to northern latitudes, the presence of relatively warmer tropical and subtropical waters further stratify the water column, a period when coccolithophorids dominate the microplankton web structure. On the other side, diatoms flourish when the wind-driven circulation expand the subarctic water masses of the CCS to the south and upwelling cells are generated. We find in our cores XRF Ca counts (1 mm resolution) highly correlate with CaCO3 measurements (R=0.56), this last one showing a general decreasing trend over the past 2 Kyrs. The Ca spectrum analysis shows significant peaks for periods centered at 28, 40, 60, 120 yr. The centennial mode of variability of the Ca record shows correlations with Drought area Index from North America. When the variance of this mode is considered, similarities arises with intensity and number of ENSO events from Equatorial archives. Decadal variations of the record are highly correlated (R>0.8) with instrumental measurements of Kaplan sea surface temperature, and the PDO. We will discuss the implications of these periods in the carbonate record and the links between them and other paleoceanographic records in the Pacific.

  17. Temperature variations in Greenland from 10 to 110 kyr b2k derived from the NGRIP ice core

    NASA Astrophysics Data System (ADS)

    Kindler, Philippe; Leuenberger, Markus; Landais, Amaelle; Guillevic, Myriam

    2013-04-01

    During the last ice age dramatic temperature variations of up to 16 °C took place in Greenland which are now known as Dansgaard-Oeschger-events (DO-events). They most probably originate from the North Atlantic oceanic and atmospheric circulation system and are characterised by an abrupt warming within decades followed by a gradual cooling over hundreds to thousands of years. We have determined local temperature variations for DO-event 1 to 25 in Greenland based on δ15N measurements from the NorthGRIP ice core, corresponding to the period from 10 to 110 kyr b2k. The record is a composite of measurements from two laboratories, Laboratoire des Sciences du Climat et de l'Environnement, Paris (DO 18 to 25) and the Climate and Environmental Physics Division of the Physics Institute of the University of Bern (DO 1 to 17) with new measurements from the beginning of the Holocene to DO 8. Temperature variations were reconstructed by reproducing the measured 15N/14N ratio of air enclosed in ice bubbles by the firn densification and heat diffusion model from Schwander. The reconstruction show temperature amplitudes for the DO-events ranging from 5 to 16 °C, thereby the corresponding rates of change can exceed 0.5 °C/decade. In order get an agreement between measured δ15N, Δdepth and Δage values with their modelled analogues, a lower accumulation rate than the one associated with the used ss09sea06bm1 time scale had to be assumed. We had to reduce the accumulation rate time dependently by 0 to nearly 40% with a mean reduction over the whole time period of 16%. With these adjustments both the Δdepth and the Δage values agree between model and measurements.

  18. Geochemistry of the Black Sea during the last 15 kyr: A protracted evolution of its hydrography and ecology

    NASA Astrophysics Data System (ADS)

    Piper, D. Z.

    2016-08-01

    The Black Sea is a 2200 m deep anoxic, marine sea connected to the Mediterranean Sea via the Dardanelles Strait, Marmara Sea, and the 3 km wide, 35 m deep Bosphorus Strait. The biogeochemistry of sediment from the Anatolia slope has recorded changes to the hydrography leading up to and following the input of Mediterranean water at ~9.4 ka (103 years B.P.), when global sea level rose to the level of the Bosphorus sill and high-salinity water from the Mediterranean began to spill into the then brackish lake. The water initially mixed little with the lake water but cascaded to the bottom where it remained essentially isolated for ~1.6 kyr, the time required to fill the basin from the bottom up at its present input rate. The accumulation of Mo in the seafloor sediments, a proxy of bottom-water anoxia, increased sharply at ~8.6 ka, when bacterial respiration in the bottom water advanced to SO42- reduction by the oxidation of organic detritus that settled out of the photic zone. Its accumulation remained elevated to ~5.6 ka, when it decreased 60%, only to again increase slightly at ~2.0 ka. The accumulation of Corg, a proxy of primary productivity, increased threefold to fourfold at ~7.8 ka, when upward mixing of the high-salinity bottom water replaced the then thin veneer of the brackish photic zone in less than 50 years. From that time onward, the accumulation of Corg, Mo, and additional trace metals has reflected the hydrography of the basin and Bosphorus Strait, controlled largely by climate.

  19. Factors associated with late diagnosis of HIV infection and missed opportunities for earlier testing.

    PubMed

    Gullón, Alejandra; Verdejo, José; de Miguel, Rosa; Gómez, Ana; Sanz, Jesús

    2016-10-01

    Late diagnosis (LD) of human immunodeficiency virus (HIV) infection continues to be a significant problem that increases disease burden both for patients and for the public health system. Guidelines have been updated in order to facilitate earlier HIV diagnosis, introducing "indicator condition-guided HIV testing". In this study, we analysed the frequency of LD and associated risk factors. We retrospectively identified those cases that could be considered missed opportunities for an earlier diagnosis. All patients newly diagnosed with HIV infection who attended Hospital La Princesa, Madrid (Spain) between 2007 and 2014 were analysed. We collected epidemiological, clinical and immunological data. We also reviewed electronic medical records from the year before the HIV diagnosis to search for medical consultations due to clinical indicators. HIV infection was diagnosed in 354 patients. The median CD4 count at presentation was 352 cells/mm(3). Overall, 158 patients (50%) met the definition of LD, and 97 (30.7%) the diagnosis of advanced disease. LD was associated with older age and was more frequent amongst immigrants. Heterosexual relations and injection drug use were more likely to be the reasons for LD than relations between men who have sex with men. During the year preceding the diagnosis, 46.6% of the patients had sought medical advice owing to the presence of clinical indicators that should have led to HIV testing. Of those, 24 cases (14.5%) were classified as missed opportunities for earlier HIV diagnosis because testing was not performed. According to these results, all health workers should pursue early HIV diagnosis through the proper implementation of HIV testing guidelines. Such an approach would prove directly beneficial to the patient and indirectly beneficial to the general population through the reduction in the risk of transmission. PMID:27144427

  20. Factors associated with late diagnosis of HIV infection and missed opportunities for earlier testing.

    PubMed

    Gullón, Alejandra; Verdejo, José; de Miguel, Rosa; Gómez, Ana; Sanz, Jesús

    2016-10-01

    Late diagnosis (LD) of human immunodeficiency virus (HIV) infection continues to be a significant problem that increases disease burden both for patients and for the public health system. Guidelines have been updated in order to facilitate earlier HIV diagnosis, introducing "indicator condition-guided HIV testing". In this study, we analysed the frequency of LD and associated risk factors. We retrospectively identified those cases that could be considered missed opportunities for an earlier diagnosis. All patients newly diagnosed with HIV infection who attended Hospital La Princesa, Madrid (Spain) between 2007 and 2014 were analysed. We collected epidemiological, clinical and immunological data. We also reviewed electronic medical records from the year before the HIV diagnosis to search for medical consultations due to clinical indicators. HIV infection was diagnosed in 354 patients. The median CD4 count at presentation was 352 cells/mm(3). Overall, 158 patients (50%) met the definition of LD, and 97 (30.7%) the diagnosis of advanced disease. LD was associated with older age and was more frequent amongst immigrants. Heterosexual relations and injection drug use were more likely to be the reasons for LD than relations between men who have sex with men. During the year preceding the diagnosis, 46.6% of the patients had sought medical advice owing to the presence of clinical indicators that should have led to HIV testing. Of those, 24 cases (14.5%) were classified as missed opportunities for earlier HIV diagnosis because testing was not performed. According to these results, all health workers should pursue early HIV diagnosis through the proper implementation of HIV testing guidelines. Such an approach would prove directly beneficial to the patient and indirectly beneficial to the general population through the reduction in the risk of transmission.

  1. Clinical development of malaria vaccines: should earlier trials be done in malaria endemic countries?

    PubMed

    Chilengi, Roma

    2009-09-01

    Clinical development of malaria vaccines has had remarkable achievements in the past decade, but an efficacious vaccine is yet to be licensed. There are many scientific and technical challenges that hamper progress ranging from parasite to host to technical and to mere traditional convention factors. This paper outlines some of the key issues along the pathway and proposes the need for much earlier phase clinical research within Africa suggesting rationale and ethical justification for doing so. Challenge model studies could particularly be employed within malaria endemic country settings which may have critical advantages to complement the currently available sites in developed countries. PMID:19617708

  2. Association of Family History of Epilepsy with Earlier Age Onset of Juvenile Myoclonic Epilepsy

    PubMed Central

    NAJAFI, Mohammad Reza; NAJAFI, Mohammad Amin; SAFAEI, Ali

    2016-01-01

    Objective Juvenile myoclonic epilepsy (JME) is supposedly the most frequent subtype of idiopathic generalized epilepsies (IGE). The aim of this study was to determine the prevalence of JME and comparison of patients’ demographics as well as timeline of the disease between positive family history epileptic patients (PFHE) and negative family history epileptic patients (NFHE) among sample of Iranian epileptic patients. Materials & Methods From Feb. 2006 to Oct. 2009, 1915 definite epileptic patients (873 females) referred to epilepsy clinics in Isfahan, central Iran, were surveyed and among them, 194 JME patients were diagnosed. JME was diagnosed by its specific clinical and EEG criteria. Patients were divided into two groups as PFHE and NFHE and data were compared between them. Results JME was responsible for 10% (194 patients) of all types of epilepsies. Of JME patients, 53% were female. In terms of family history of epilepsy, 40% were positive. No significant differences was found between PFHE and NFHE groups as for gender (P>0.05). Age of epilepsy onset was significantly earlier in PFHE patients (15 vs. 22 yr, P<0.001). Occurrence of JME before 18 yr old among PFHE patients was significantly higher (OR=2.356, P=0.007). Conclusion A family history of epilepsy might be associated with an earlier age of onset in patients with JME. PMID:27247579

  3. NMR-based fecal metabolomics fingerprinting as predictors of earlier diagnosis in patients with colorectal cancer

    PubMed Central

    Lin, Yan; Ma, Changchun; Liu, Chengkang; Wang, Zhening; Yang, Jurong; Liu, Xinmu; Shen, Zhiwei; Wu, Renhua

    2016-01-01

    Colorectal cancer (CRC) is a growing cause of mortality in developing countries, warranting investigation into its earlier detection for optimal disease management. A metabolomics based approach provides potential for noninvasive identification of biomarkers of colorectal carcinogenesis, as well as dissection of molecular pathways of pathophysiological conditions. Here, proton nuclear magnetic resonance spectroscopy (1HNMR) -based metabolomic approach was used to profile fecal metabolites of 68 CRC patients (stage I/II=20; stage III=25 and stage IV=23) and 32 healthy controls (HC). Pattern recognition through principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) was applied on 1H-NMR processed data for dimension reduction. OPLS-DA revealed that each stage of CRC could be clearly distinguished from HC based on their metabolomic profiles. Successive analyses identified distinct disturbances to fecal metabolites of CRC patients at various stages, compared with those in cancer free controls, including reduced levels of acetate, butyrate, propionate, glucose, glutamine, and elevated quantities of succinate, proline, alanine, dimethylglycine, valine, glutamate, leucine, isoleucine and lactate. These altered fecal metabolites potentially involved in the disruption of normal bacterial ecology, malabsorption of nutrients, increased glycolysis and glutaminolysis. Our findings revealed that the fecal metabolic profiles of healthy controls can be distinguished from CRC patients, even in the early stage (stage I/II), highlighting the potential utility of NMR-based fecal metabolomics fingerprinting as predictors of earlier diagnosis in CRC patients. PMID:27107423

  4. Light pollution is associated with earlier tree budburst across the United Kingdom.

    PubMed

    Ffrench-Constant, Richard H; Somers-Yeates, Robin; Bennie, Jonathan; Economou, Theodoros; Hodgson, David; Spalding, Adrian; McGregor, Peter K

    2016-06-29

    The ecological impact of night-time lighting is of concern because of its well-demonstrated effects on animal behaviour. However, the potential of light pollution to change plant phenology and its corresponding knock-on effects on associated herbivores are less clear. Here, we test if artificial lighting can advance the timing of budburst in trees. We took a UK-wide 13 year dataset of spatially referenced budburst data from four deciduous tree species and matched it with both satellite imagery of night-time lighting and average spring temperature. We find that budburst occurs up to 7.5 days earlier in brighter areas, with the relationship being more pronounced for later-budding species. Excluding large urban areas from the analysis showed an even more pronounced advance of budburst, confirming that the urban 'heat-island' effect is not the sole cause of earlier urban budburst. Similarly, the advance in budburst across all sites is too large to be explained by increases in temperature alone. This dramatic advance of budburst illustrates the need for further experimental investigation into the impact of artificial night-time lighting on plant phenology and subsequent species interactions. As light pollution is a growing global phenomenon, the findings of this study are likely to be applicable to a wide range of species interactions across the world. PMID:27358370

  5. Secular trend of earlier onset and decelerated development of third molars: evidence from Croatia.

    PubMed

    Sasso, Anja; Legovic, Mario; Mady Maricic, Barbara; Pavlic, Andrej; Spalj, Stjepan

    2015-04-01

    The purpose of this study was to evaluate the influence of the secular trend on development of third molars in 30 years period in Littoral region of Croatia. A total of 1103 panoramic radiographs of subjects aged from 6 to 18 years were analysed. First group comprised 531 panoramic radiographs (258 girls) taken from year period 1977 till 1979 and second group 572 radiographs (325 girls) taken from year period 2007 till 2009. Demirjian's method was used to determine the developmental stage of third molars. A secular trend in 30 years period was observed as earlier onset of third molars development in boys (6 months on average maxillary and 11 months mandibular) and girls (6 months for maxillary and 4 months for mandibular). Now-a-days, an increase in mineralisation for one Demirjian stage occurs at a slower pace of 5.2 months in boys and 3.4 in girls in maxilla and 2.3 or 2 months in mandible for boys and girls, respectively. The study showed a secular trend present as earlier onset but decelerated development of third molars in both genders and both jaws.

  6. Decreasing the required lumbar extensor moment induces earlier onset of flexion relaxation.

    PubMed

    Zwambag, Derek P; De Carvalho, Diana E; Brown, Stephen H M

    2016-10-01

    Flexion relaxation (FR) is characterized by the lumbar erector spinae (LES) becoming myoelectrically silent near full trunk flexion. This study was designed to: (1) determine if decreasing the lumbar moment during flexion would induce FR to occur earlier; (2) characterize thoracic and abdominal muscle activity during FR. Ten male participants performed four trunk flexion/extension movement conditions; lumbar moment was altered by attaching 0, 5, 10, or 15lb counterweights to the torso. Electromyography (EMG) was recorded from eight trunk muscles. Lumbar moment, lumbar flexion and trunk inclination angles were calculated at the critical point of LES inactivation (CPLES). Results demonstrated that counterweights decreased the lumbar moment and lumbar flexion angle at CPLES (p<0.0001 and p=0.0029, respectively); the hypothesis that FR occurs earlier when lumbar moment is reduced was accepted. The counterweights did not alter trunk inclination at CPLES (p=0.1987); this is believed to result from an altered hip to spine flexion ratio when counterweights were attached. Lumbar multifidus demonstrated FR, similar to LES, while thoracic muscles remained active throughout flexion. Abdominal muscles activated at the same instant as CPLES, except in the 15lb condition where abdominal muscles activated before CPLES resulting in a period of increased co-contraction. PMID:27267174

  7. Light pollution is associated with earlier tree budburst across the United Kingdom.

    PubMed

    Ffrench-Constant, Richard H; Somers-Yeates, Robin; Bennie, Jonathan; Economou, Theodoros; Hodgson, David; Spalding, Adrian; McGregor, Peter K

    2016-06-29

    The ecological impact of night-time lighting is of concern because of its well-demonstrated effects on animal behaviour. However, the potential of light pollution to change plant phenology and its corresponding knock-on effects on associated herbivores are less clear. Here, we test if artificial lighting can advance the timing of budburst in trees. We took a UK-wide 13 year dataset of spatially referenced budburst data from four deciduous tree species and matched it with both satellite imagery of night-time lighting and average spring temperature. We find that budburst occurs up to 7.5 days earlier in brighter areas, with the relationship being more pronounced for later-budding species. Excluding large urban areas from the analysis showed an even more pronounced advance of budburst, confirming that the urban 'heat-island' effect is not the sole cause of earlier urban budburst. Similarly, the advance in budburst across all sites is too large to be explained by increases in temperature alone. This dramatic advance of budburst illustrates the need for further experimental investigation into the impact of artificial night-time lighting on plant phenology and subsequent species interactions. As light pollution is a growing global phenomenon, the findings of this study are likely to be applicable to a wide range of species interactions across the world.

  8. Light pollution is associated with earlier tree budburst across the United Kingdom

    PubMed Central

    Somers-Yeates, Robin; Bennie, Jonathan; Hodgson, David; Spalding, Adrian

    2016-01-01

    The ecological impact of night-time lighting is of concern because of its well-demonstrated effects on animal behaviour. However, the potential of light pollution to change plant phenology and its corresponding knock-on effects on associated herbivores are less clear. Here, we test if artificial lighting can advance the timing of budburst in trees. We took a UK-wide 13 year dataset of spatially referenced budburst data from four deciduous tree species and matched it with both satellite imagery of night-time lighting and average spring temperature. We find that budburst occurs up to 7.5 days earlier in brighter areas, with the relationship being more pronounced for later-budding species. Excluding large urban areas from the analysis showed an even more pronounced advance of budburst, confirming that the urban ‘heat-island’ effect is not the sole cause of earlier urban budburst. Similarly, the advance in budburst across all sites is too large to be explained by increases in temperature alone. This dramatic advance of budburst illustrates the need for further experimental investigation into the impact of artificial night-time lighting on plant phenology and subsequent species interactions. As light pollution is a growing global phenomenon, the findings of this study are likely to be applicable to a wide range of species interactions across the world. PMID:27358370

  9. Ontogenic changes rather than difference in temperature cause understory trees to leaf out earlier.

    PubMed

    Vitasse, Yann

    2013-04-01

    In a temperate climate, understory trees leaf out earlier than canopy trees, but the cause of this discrepancy remains unclear. This study aims to investigate whether this discrepancy results from ontogenic changes or from microclimatic differences. Seedlings of five deciduous tree species were grown in spring 2012 in the understory and at canopy height using a 45-m-high construction crane built into a mature mixed forest in the foothills of the Swiss Jura Mountains. The leaf development of these seedlings, as well as conspecific adults, was compared, taking into account the corresponding microclimate. The date of leaf unfolding occurred 10-40 d earlier in seedlings grown at canopy level than in conspecific adults. Seedlings grown in the understory flushed c. 6 d later than those grown at canopy height, which can be attributed to the warmer temperatures recorded at canopy height (c. 1°C warmer). This study demonstrates that later leaf emergence of canopy trees compared with understory trees results from ontogenic changes and not from the vertical thermal profile that exists within forests. This study warns against the assumption that phenological data obtained in warming and photoperiod experiments on juvenile trees can be used for the prediction of forest response to climate warming. PMID:23347086

  10. Empirical corroboration of an earlier theoretical resolution to the UV paradox of insect polarized skylight orientation.

    PubMed

    Wang, Xin; Gao, Jun; Fan, Zhiguo

    2014-02-01

    It is surprising that many insect species use only the ultraviolet (UV) component of the polarized skylight for orientation and navigation purposes, while both the intensity and the degree of polarization of light from the clear sky are lower in the UV than at longer (blue, green, red) wavelengths. Why have these insects chosen the UV part of the polarized skylight? This strange phenomenon is called the "UV-sky-pol paradox". Although earlier several speculations tried to resolve this paradox, they did this without any quantitative data. A theoretical and computational model has convincingly explained why it is advantageous for certain animals to detect celestial polarization in the UV. We performed a sky-polarimetric approach and built a polarized skylight sensor that models the processing of polarization signals by insect photoreceptors. Using this model sensor, we carried out measurements under clear and cloudy sky conditions. Our results showed that light from the cloudy sky has maximal degree of polarization in the UV. Furthermore, under both clear and cloudy skies the angle of polarization of skylight can be detected with a higher accuracy. By this, we corroborated empirically the soundness of the earlier computational resolution of the UV-sky-pol paradox. PMID:24402685

  11. Does earlier snowmelt lead to greater CO2 sequestration in two low Arctic tundra ecosystems?

    NASA Astrophysics Data System (ADS)

    Humphreys, Elyn R.; Lafleur, Peter M.

    2011-05-01

    Some studies have reported that spring warming and earlier snowmelt leads to increased CO2 sequestration in Arctic terrestrial ecosystems. We measured tundra-atmosphere CO2 exchange via eddy covariance at two low Arctic sites (mixed upland tundra and sedge fen) in central Canada over multiple snow-free periods to assess this hypothesis. Both sites were net sinks for atmospheric CO2 in all years (2004-2010), but with high interannual variability. Despite a large range in snowmelt date (30 days), we did not find a statistically significant correlation between seasonal accumulated net ecosystem production (NEP) and snowmelt for either site. Although many factors can influence seasonal total NEP, our analysis shows that annual variations in photosynthetic capacity, likely driven by changes in leaf area, is a dominating control at these Arctic sites. At the upland tundra site, protection of overwintering buds by a longer duration of deep snow appears to be linked to greater photosynthetic capacity and NEP. Whereas at the fen site, sedge growth benefits from earlier snowmelt resulting in a strong correlation with early season NEP and an increase in total study period NEP with increasing growing degree days. These results highlight the complexity of interannual variation in ecosystem CO2 exchange in Arctic tundra and suggest that snowmelt date alone cannot predict seasonal, or annual, NEP.

  12. Ontogenic changes rather than difference in temperature cause understory trees to leaf out earlier.

    PubMed

    Vitasse, Yann

    2013-04-01

    In a temperate climate, understory trees leaf out earlier than canopy trees, but the cause of this discrepancy remains unclear. This study aims to investigate whether this discrepancy results from ontogenic changes or from microclimatic differences. Seedlings of five deciduous tree species were grown in spring 2012 in the understory and at canopy height using a 45-m-high construction crane built into a mature mixed forest in the foothills of the Swiss Jura Mountains. The leaf development of these seedlings, as well as conspecific adults, was compared, taking into account the corresponding microclimate. The date of leaf unfolding occurred 10-40 d earlier in seedlings grown at canopy level than in conspecific adults. Seedlings grown in the understory flushed c. 6 d later than those grown at canopy height, which can be attributed to the warmer temperatures recorded at canopy height (c. 1°C warmer). This study demonstrates that later leaf emergence of canopy trees compared with understory trees results from ontogenic changes and not from the vertical thermal profile that exists within forests. This study warns against the assumption that phenological data obtained in warming and photoperiod experiments on juvenile trees can be used for the prediction of forest response to climate warming.

  13. Investigating the Impacts of Climate, Hydrology, and Asian Monsoon Intensity on a 13 kyr Speleothem Record from Laos

    NASA Astrophysics Data System (ADS)

    Yang, Hongying

    I present a high- resolution record of Southeast Asian Monsoon (SEAM) evolution compiled from delta18O measurements conducted on five U-Th dated speleothems from Tham Mai Cave in northern Laos (20.75N, 102.65E), a key site at the interface between the Indian and East Asian monsoon systems. The speleothem oxygen isotope records are tied to robust uranium-series dates and indicate the records span from 0.79 to 13 kyr BP with sub-decadal resolution. During the Holocene, the Tham Mai speleothem delta18O records are characterized by lower values during the early to mid-Holocene with increasing values towards the late Holocene. This is similar to trends seen throughout the Asian monsoon region, reflecting the strong insolation control on monsoon strength and ITCZ position. The Younger Dryas is characterized by an abrupt delta 18O increase and is synchronous with the even observed in Chinese speleothem records and Greenland ice cores within age uncertainties. This suggests that the SEAM weakened in sync with high-latitude abrupt cooling events. Four speleothems from Tham Mai cave grew contemporaneously from 4,300 years BP to 9,000 years BP. These four samples show a similar delta 18O pattern, despite a 1.2‰ between sample delta18 O variability is observed. A lumped parameter forward model method (KarstFor model) is used to assess to which extent this 1.2‰ discrepancy can be attributed to hydrological variability. Results suggested that this 1.2‰ discrepancy can be generated due to hydrological variability within one cave. To better interpret interannual delta18O variability in high-resolution oxygen isotope records in the Asian Monsoon region, I utilize existing simulations from a spectrally nudged isotope-enabled general circulation model (IsoGSM) to investigate the climatic controls on delta18 Op at four cave locations along the Asian monsoon region. Results show that delta18Op at the four cave sites reflects large-scale ocean-atmosphere processes, instead of

  14. South Asian summer monsoon variability during the last ˜54 kyrs inferred from surface water salinity and river runoff proxies

    NASA Astrophysics Data System (ADS)

    Gebregiorgis, D.; Hathorne, E. C.; Sijinkumar, A. V.; Nath, B. Nagender; Nürnberg, D.; Frank, M.

    2016-04-01

    The past variability of the South Asian Monsoon is mostly known from records of wind strength over the Arabian Sea while high-resolution paleorecords from regions of strong monsoon precipitation are still lacking. Here, we present records of past monsoon variability obtained from sediment core SK 168/GC-1, which was collected at the Alcock Seamount complex in the Andaman Sea. We utilize the ecological habitats of different planktic foraminiferal species to reconstruct freshwater-induced stratification based on paired Mg/Ca and δ18O analyses and to estimate seawater δ18O (δ18Osw). The difference between surface and thermocline temperatures (ΔT) and δ18Osw (Δδ18Osw) is used to investigate changes in upper ocean stratification. Additionally, Ba/Ca in G. sacculifer tests is used as a direct proxy for riverine runoff and sea surface salinity (SSS) changes related to monsoon precipitation on land. Our Δδ18Osw time series reveals that upper ocean salinity stratification did not change significantly throughout the last glacial suggesting little influence of NH insolation changes. The strongest increase in temperature gradients between the mixed layer and the thermocline is recorded for the mid-Holocene and indicate the presence of a significantly shallower thermocline. In line with previous work, the δ18Osw and Ba/Ca records demonstrate that monsoon climate during the LGM was characterized by a significantly weaker southwest monsoon circulation and strongly reduced runoff. Based on our data the South Asian Summer Monsoon (SAM) over the Irrawaddyy strengthened gradually after the LGM beginning at ∼18 ka. This is some 3 kyrs before an increase of the Ba/Ca record from the Arabian Sea and indicates that South Asian Monsoon climate dynamics are more complex than the simple N-S displacement of the ITCZ as generally described for other regions. Minimum δ18Osw values recorded during the mid-Holocene are in phase with Ba/Ca marking a stronger monsoon precipitation

  15. Distal deltaic deposits document hydrological variability during the past 30 kyrBP in Lake Towuti, Indonesia

    NASA Astrophysics Data System (ADS)

    Vogel, Hendrik; Russell, James M.; Yudawati Cahyarini, Sri; Bijaksana, Satria; Wattrus, Nigel; Rethemeyer, Janet; Melles, Martin

    2014-05-01

    Lake Towuti (2.75°S, 121.5°E; 318 m a.s.l.) is a, 560 km2, 200-m deep tectonic lake at the downstream end of the Malili lake system, a set of five, ancient (1-2 MYr) tectonic lakes in central Sulawesi, Indonesia. The Mahalona River constitutes the largest tributary and connects Lake Towuti with the two upstream lakes Matano and Mahalona. The Mahalona River Delta is prograding into the >200m deep northern basin of Lake Towuti. Tracing past variability of Mahalona River discharge is therefore an important puzzle piece for the understanding of depositional dynamics in Lake Towuti as well as catchment hydrology and hydrological connectivity between the Malili Lakes. Distal deltaic deposits can help identifying past variability in river discharge and delta dynamics. Using highly resolved seismic reflection data collected between 2007-2013 we identified a stack of acoustically laminated reflections in Towuti's extensive and morphologically flat deep northern basin. For detailed characterization of these acoustic features we collected a c. 20m long piston core from the basin centre at 200 m water depth reaching back to c. 30 kyrBP. Sediments in this piston core consist to 75% of mass wasting deposits (MWD) of variable thickness that are intercalated with pelagic muds (25%). MWD appear mostly homogenous (silt- to finesand-sized siliciclastics with high amounts of terrestrial plant macrofossils) with only thin (1-3 cm) basal sand layers and clay caps (<1 cm). Pelagic muds appear as thin to medium bedded slightly silty clays that are clearly distinguishable from MWD. The position of MWD identified in our piston core nicely correlates with acoustically laminated reflections identified in seismic profiles crossing the coring site. Based on these combined sedimentological and acoustic datasets we interpret MWD in Towuti's northern basin as distal deltaic deposits originating from the Mahalona River Delta. Frequencies and percentages (in terms of lithofacies contribution) of

  16. Slip-Rate on the Haiyuan Fault (Gansu, China), Over Time Scales of 10 yr to 10 kyr

    NASA Astrophysics Data System (ADS)

    Lasserre, C.; Cavalié, O.; Doin, M.; Peltzer, G.; Sun, J.; Shen, Z.; Wang, Q.; Xu, X.

    2006-12-01

    deformation across the fault, consistent with left-lateral slip at a rate of ~1 cm/yr. The steep velocity gradient at the fault suggests an apparently shallow locking depth of 5 km that may be indicative of a weak fault zone. The InSAR rate is consistent with both the decadal slip-rate derived from GPS measurement campaigns in 1994, 1996, 1999 and 2005, and the Holocene slip-rate inferred from the offset morphology. These observations suggest a stable behavior of the fault over the past 10 kyr.

  17. Multi-proxy sedimentary record from Lake Ghirla (N-Italy) reveals hydro-climatic variations and periods of anthropogenic activities during the past 13 kyrs

    NASA Astrophysics Data System (ADS)

    Wirth, Stefanie B.; Gilli, Adrian; Sessions, Alex L.

    2016-04-01

    Lake Ghirla is a small lake that lies in the southern foothills of the Central Alps near the Swiss-Italian border. Climatically, the region is influenced by North Atlantic and Mediterranean weather systems and is frequently affected by severe storm tracks causing heavy precipitation. The catchment with Permian granites and gneisses contains Pb in amounts significant for mining as well as less important concentrations of Cu, As and U. This sensitive setting makes Lake Ghirla a promising site to reconstruct hydro-climatic variations and to track human activity by means of elevated heavy metal concentrations in the lake sediments. The recovered sediment core comprises the entire Younger Dryas-Holocene time period and was analyzed for (i) sedimentological changes to identify flood deposits, for (ii) the hydrogen isotopic composition of terrestrial plant waxes (plant-wax D/H) to constrain hydro-climatic changes, and for (iii) variations of the elemental composition (XRF core scanning, ICP-MS) to understand anthropogenic impacts. During the past 13 kyrs, we observe a high variability of floods with peak periods appearing at ~11, 10.6-8.2, 6-4.9, 2.8-2.7, 2.6-2.4, 1.2-1 and 0.4-0.1 (LIA) cal kyr BP. From a hydro-climatic perspective, the most remarkable result from the plant-wax D/H data is that the Younger Dryas is characterized by no significant change and that the 2.8-2.7 kyr BP and LIA intervals show an increase of plant-wax D/H values. Hence, during these three cool climatic periods temperature effects cannot be solely responsible for plant-wax D/H variation. The southward migration of the westerly storm tracks above the North Atlantic due to climate cooling must have led to a more southern and thus isotopically enriched moisture source for the southern Alps. This moisture-source change likely counter-balanced or even over-rode the temperature-driven isotope effect. Increased sedimentary Cu concentrations at 3.8-3.3 kyr BP are the first evidence for the presence of

  18. Orbital-scale stratigraphy and paleoenvironmental changes in the Japan Sea during the last 230 kyr based on oxygen and carbon isotopes of benthic foraminifera

    NASA Astrophysics Data System (ADS)

    Nakahashi, K.; Kimoto, K.; Tada, R.; Tamaki, K.

    2009-12-01

    Paleoceanographic conditions in the Japan Sea changed drastically during the late Quaternary in association with orbital and suborbital cycles and glacio-eustatic sea level changes. However, few studies had been examined long-term sediment records older than last intergracial period because of the lack of long cores which contains continuous paleoclimatic records and difficulties reconstructing high-resolution age models. Especially disappearance of benthic foraminifers by euxinic bottom water conditions during glacial maxima makes it difficult to understand specific bottom water environments. In this study, we reconstructed benthic foraminiferal stable isotopic stratigraphy of the Japan Sea core with the resolution in 2 kyr. and compared the global stack of benthic foraminfieral δ18O curve (LR04, Lisiecki & Raymo, 2005). The investigated core MD01-2408, was recovered from 806 m water depth, off Akita Prefecture during IMAGES VII cruise. It had recorded continuous paleoenvironmental histories during the last 230 kyr through the core. This core was mainly consisted of alternating layers of homogeneous light colored silty clay and laminated or bioturbated dark colored silty clay, occasionally intercalating volcanic ash layers. The most abundant benthic foraminiferal species are Uvigerina akitaensis, Angulogerina kokozuraensis and Islandiella norcrossi. Abundance of these species fluctuated drastically through the core. No benthic foraminifera is found in two dark layer intervals 4 ~ 5 mbsf and 25 ~ 25.5 mbsf, corresponding 15 ~ 25 kyr and 149 ~ 152 kyr, respectively, probably representing super anoxic bottom water conditions(Oba et al 1984 1991;Tada et al., 1999). δ18O of U. akitaensis and A. kokozuraensis showed a similar values with a precision of ± 0.27‰ and it was inferred that both species had similar habitat. δ18O of both species in core MD01-2408 fluctuated with the range of 2‰ over 230 kyr. Although benthic δ18O stack of LR04 reached to 5 ‰ during

  19. Late Miocene to Early Pleistocene Paleo-Erosion Rates and Provenance Change in the NE Argentinian Andes: Apparent Coupling of Sediment Fluxes with 400-kyr Eccentricity Cycles

    NASA Astrophysics Data System (ADS)

    Burch Fisher, G.; Amidon, William H.; Burbank, Douglas W.; Luna, Lisa V.

    2016-04-01

    Proposed linkages among climate, erosion, and tectonics provide an appealing framework for interpretation of the interplay among tectonic forcing, topographic form, climatic inputs, and rates of erosion. More rapid deformation is hypothesized to create higher and steeper topography that focuses precipitation, drives faster erosion, and enhances slip rates. But, a determination of cause and effect or synchrony in any proposed tectonic-climate-erosion coupling is commonly difficult to extract. Typically constraints on age and provenance are too loose, or records are too short, irregular, or sparse to permit nuanced interpretations. In fact, clear records in active orogens that reveal a persistent climatic imprint on erosion rates (such as ones scaled by Milankovich-type cyclicity) are rare, especially for pre-Quaternary intervals. Here, along the Rio Iruya on the eastern flank of the NE Argentinian Andes, we exploit a unique field setting in which a 100-m-deep canyon has been cut during the past century through a 6-km-thick tilted sequence of upper Cenozoic synorogenic strata. Sample ages in the Iruya gorge are provided by a high-quality magnetostratigraphy (~100-kyr resolution) that is calibrated with U-Pb zircon ages of interbedded tephra. Detrital zircon ages and quartz trace elements provide a provenance record for the sampled section. Here, we report 49 new detrital 10Be cosmogenic paleo-erosion rates spanning from the Late Miocene to Early Pleistocene (~5.8 to 1.8 Ma). Paired with each 10Be sample that is younger than ~3.3 Ma, 23 26Al samples provide a second proxy for paleo-erosion rates. 20th-century canyon cutting obviates the typical uncertainties associated with unconstrained Late Quaternary cosmogenic production due to exhumation prior to sampling. Three different erosion-rate regimes are apparent: from 1.8 to 2.3 Ma, rates are high with few oscillations; from 2.3 to 4.0 Ma, rates oscillate by a factor of 5 on a ~400-kyr timescale; and from 5.8 to 4.0 Ma

  20. Nd isotopic composition from seawater and sediments of the South China Sea and the Philippine Sea : implications for hydrology of the Pacific Ocean during the last 25 kyr

    NASA Astrophysics Data System (ADS)

    Wu, Qiong; Colin, Christophe; Liu, Zhifei; Thil, Francois; Douville, Eric; Frank, Norbert

    2014-05-01

    Nd isotopic compositions (ɛNd) of foraminifera from one gravity core (MD05-2904; 19°27.32' 116°15.15', 2066 m water depth) and 10 seawater profiles from the northern South China Sea (SCS) and the Philippine Sea (western Pacific Ocean) were measured to (1) constrain the Nd isotopic composition of water masses along the western Pacific and the SCS that are still poorly documented ; (2) track hydrological exchange between the SCS and western Pacific trough the Luzon strait ; (3) to test the ability of foraminifera to establish seawater ɛNd ; (4) to establish past hydrological changes of deep-water circulation in the western Pacific Ocean during the last 25 kyr. Distribution of ɛNd seawater of the Northern SCS and west Pacific indicate that the SCS is dominated by three water masses, the South China Sea Tropical Water (SCSTW) (~-7.7), South China Sea Intermediate Water (SCSIW) (~-3.6) and the Pacific Deep Water (PDW) (~-4). Our results indicate that at present time ɛNd of deep and intermediate waters of the SCS is representative of the PDW. Different analytical procedures to extract seawater ɛNd from foraminiferas (benthic and planktonic) and Fe-Mn coatings precipitated on the sediments have been tested and permit to determine that only ɛNd obtained from foraminiferas are reliable to seawater ɛNd in the South China Sea. A first record of past seawater ɛNd obtained from foraminifera of the core MD05-2904 (northern part of the SCS) indicate major change of the hydrology of the West Pacific during the last 25 kyr. ɛNd values variations indicate two negative excursion during at Heinrich Stadial 1(~16 kyr BP) and ~10 kyr BP implying a reorganization of the deep circulation in the Pacific. Such results are compared with other proxies of deep-water circulation to propose new insight in the role of the southern deep-water pacific circulation on climate during the last deglaciation.

  1. Grain-size based sea-level reconstruction in the south Bohai Sea during the past 135 kyr

    NASA Astrophysics Data System (ADS)

    Yi, Liang; Chen, Yanping

    2013-04-01

    marine surface and core samples, and to quantitatively reconstruct sea-level variation since the late Pleistocene in the south Bohai Sea, China. New insights into regional relative sea-level changes since the late Pleistocene are obtained (Yi et al., 2012): (1) The grain size of surface and core samples can be mathematically partitioned using the Weibull distribution into four components. These four components with differing modal sizes and percentages could be interpreted as a long-term suspension component, which only settles under low turbulence conditions, sortable silt and very fine sand components transported by suspension during greater turbulence and bedload transport component, respectively. (2) Through regression and rigorous verification techniques, the reference water level could be reconstructed from sediment grain size. The reconstruction quantitatively extends the regional relative sea-level history to the late Pleistocene, providing a comparatively long dataset to evaluate regional sea-level variability. (3) We find no evidence of a sea-level high stand during MIS3 but rather a substantial regression during 70-30 cal kyr BP and potentially exposed land during 38-20 cal kyr BP. These results for the south Bohai Sea are in good agreement with published global sea-level records for the late Pleistocene, implying similarities between local and global sea-level patterns. Therefore, it is concluded that grain-size based sea-level reconstruction provide results that are comparable to other reconstruction methods and demonstrates great potential application for future works. (The data was shared on http://hurricane.ncdc.noaa.gov/) References Chappell, J., Omura, A., Esat, T., McCulloch, M., Pandolfi, J., Ota, Y., Pillans, B., 1996. Reconciliation of late Quaternary sea levels derived from coral terraces at Huon Peninsula with deep sea oxygen isotope records. Earth and Planetary Science Letters 141, 227-236. Chappell, J., Shackleton, N.J., 1986. Oxygen isotopes

  2. Detecting earlier indicators of homelessness in the free text of medical records.

    PubMed

    Redd, Andrew; Carter, Marjorie; Divita, Guy; Shen, Shuying; Palmer, Miland; Samore, Matthew; Gundlapalli, Adi V

    2014-01-01

    Early warning indicators to identify US Veterans at risk of homelessness are currently only inferred from administrative data. References to indicators of risk or instances of homelessness in the free text of medical notes written by Department of Veterans Affairs (VA) providers may precede formal identification of Veterans as being homeless. This represents a potentially untapped resource for early identification. Using natural language processing (NLP), we investigated the idea that concepts related to homelessness written in the free text of the medical record precede the identification of homelessness by administrative data. We found that homeless Veterans were much higher utilizers of VA resources producing approximately 12 times as many documents as non-homeless Veterans. NLP detected mentions of either direct or indirect evidence of homelessness in a significant portion of Veterans earlier than structured data.

  3. Warming and earlier spring increase Western U.S. forest wildfire activity

    USGS Publications Warehouse

    Westerling, A.L.; Hidalgo, H.G.; Cayan, D.R.; Swetnam, T.W.

    2006-01-01

    Western United States forest wildfire activity is widely thought to have increased in recent decades, yet neither the extent of recent changes nor the degree to which climate may be driving regional changes in wildfire has been systematically documented. Much of the public and scientific discussion of changes in western United States wildfire has focused instead on the effects of 19th- and 20th-century land-use history. We compiled a comprehensive database of large wildfires in western United States forests since 1970 and compared it with hydroclimatic and land-surface data. Here, we show that large wildfire activity increased suddenly and markedly in the mid-1980s, with higher large-wildfire frequency, longer wildfire durations, and longer wildfire seasons. The greatest increases occurred in mid-elevation, Northern Rockies forests, where land-use histories have relatively little effect on fire risks and are strongly associated with increased spring and summer temperatures and an earlier spring snowmelt.

  4. Earlier predictors of eating disorder symptoms in 9-year-old children. A longitudinal study.

    PubMed

    Parkinson, Kathryn N; Drewett, Robert F; Le Couteur, Ann S; Adamson, Ashley J

    2012-08-01

    The aim of the study was to examine predictors of eating disorder symptoms in a population based sample at the earliest age at which they can be measured using the Children's Eating Attitudes Test. Data were collected from the longitudinal Gateshead Millennium Study cohort; 609 children participated in the 7 year data sweep (and their mothers and teachers), and 589 children participated in the 9 year data sweep. Eating disorder symptoms at 9 years were higher in boys, and in children from more deprived families. Higher eating disorder symptoms were associated with more body dissatisfaction at 9 years. Higher symptoms were predicted by higher levels of dietary restraint and of emotional symptoms, but not greater body dissatisfaction, 2 years earlier. The study showed that some correlates of high eating disorder symptoms found in adolescents and adults are also found in children, before the rise in diagnosable eating disorders over the pubertal period.

  5. Kathu Townlands: a high density Earlier Stone Age locality in the interior of South Africa.

    PubMed

    Walker, Steven J H; Lukich, Vasa; Chazan, Michael

    2014-01-01

    Kathu Townlands is a high density Earlier Stone Age locality in the Northern Cape Province, South Africa. Here we present the first detailed information on this locality based on analysis of a sample of lithic material from excavations by P. Beaumont and field observations made in the course of fieldwork in 2013. The results confirm the remarkably high artefact density at Kathu Townlands and do not provide evidence consistent with high energy transport as a mechanism of site formation, suggesting that Kathu Townlands was the site of intensive exploitation of highly siliceous outcroppings of banded iron formation. The results presented here provide a first step towards understanding this complex locality and point to the need for further research and the importance of preserving this locality in the face of intensive and rapid development.

  6. Earlier onset of the spring fine dust season in the southwestern United States

    NASA Astrophysics Data System (ADS)

    Hand, J. L.; White, W. H.; Gebhart, K. A.; Hyslop, N. P.; Gill, T. E.; Schichtel, B. A.

    2016-04-01

    Particulate matter (PM)2.5 dust concentrations (mineral particles with aerodynamic diameters less than 2.5 µm) typically peak in spring and early summer at rural and remote sites across the southwestern United States. Trend analyses indicate that springtime regional mean PM2.5 dust concentrations have increased from 1995 to 2014, especially in March (5.4% yr-1, p < 0.01). This increase reflects an earlier onset of the spring dust season across the Southwest by 1 to 2 weeks over the 20 year time period. March dust concentrations were strongly correlated with the Pacific Decadal Oscillation index (r = -0.65, p < 0.01), which was mostly in its negative phase from 2007 to 2014, during which the region was drier, windier, and less vegetated. The positive spring trend and its association with large-scale climate variability have several important implications for visibility, particulate matter, health effects, and the hydrologic cycle in the region.

  7. Towards an earlier diagnosis of Alzheimer's disease presenting with visuospatial disorders (posterior cortical atrophy).

    PubMed

    Vighetto, A

    2013-10-01

    Progressive visual complaints related to visuospatial disorders, and less often to visuoperceptual disorders, may be the presenting and isolated manifestation of a focal degeneration in the posterior cortical areas, called posterior cortical atrophy (PCA). PCA is a clinical syndrome corresponding to a focal variant of Alzheimer's disease in 80% of cases. The predominant dysfunction in the occipitoparietal pathways results in predominant visuospatial disorders, manifesting primarily as dorsal simultanagnosia, alone or associated with other symptoms of Balint's syndrome. PCA is rare and affects young patients who are fully aware of their deficits. Diagnosis of PCA is often delayed, due to insidious onset and development of symptoms, and to poor awareness of the condition in the medical community. An earlier diagnosis requires both better knowledge of PCA among ophthalmologists and neurologists and better recognition of visual complaints, leading to simple bedside tasks that can tackle the syndrome.

  8. Kathu Townlands: A High Density Earlier Stone Age Locality in the Interior of South Africa

    PubMed Central

    Walker, Steven J. H.; Lukich, Vasa; Chazan, Michael

    2014-01-01

    Kathu Townlands is a high density Earlier Stone Age locality in the Northern Cape Province, South Africa. Here we present the first detailed information on this locality based on analysis of a sample of lithic material from excavations by P. Beaumont and field observations made in the course of fieldwork in 2013. The results confirm the remarkably high artefact density at Kathu Townlands and do not provide evidence consistent with high energy transport as a mechanism of site formation, suggesting that Kathu Townlands was the site of intensive exploitation of highly siliceous outcroppings of banded iron formation. The results presented here provide a first step towards understanding this complex locality and point to the need for further research and the importance of preserving this locality in the face of intensive and rapid development. PMID:25058317

  9. Patient- and system-related barriers for the earlier diagnosis of colorectal cancer

    PubMed Central

    Wahls, Terry L; Peleg, Ika

    2009-01-01

    Background A cohort of colorectal cancer (CRC) patients represents an opportunity to study missed opportunities for earlier diagnosis. Primary objective: To study the epidemiology of diagnostic delays and failures to offer/complete CRC screening. Secondary objective: To identify system- and patient-related factors that may contribute to diagnostic delays or failures to offer/complete CRC screening. Methods Setting: Rural Veterans Administration (VA) Healthcare system. Participants: CRC cases diagnosed within the VA between 1/1/2000 and 3/1/2007. Data sources: progress notes, orders, and pathology, laboratory, and imaging results obtained between 1/1/1995 and 12/31/2007. Completed CRC screening was defined as a fecal occult blood test or flexible sigmoidoscopy (both within five years), or colonoscopy (within 10 years); delayed diagnosis was defined as a gap of more than six months between an abnormal test result and evidence of clinician response. A summary abstract of the antecedent clinical care for each patient was created by a certified gastroenterologist (GI), who jointly reviewed and coded the abstracts with a general internist (TW). Results The study population consisted of 150 CRC cases that met the inclusion criteria. The mean age was 69.04 (range 35-91); 99 (66%) were diagnosed due to symptoms; 61 cases (46%) had delays associated with system factors; of them, 57 (38% of the total) had delayed responses to abnormal findings. Fifteen of the cases (10%) had prompt symptom evaluations but received no CRC screening; no patient factors were identified as potentially contributing to the failure to screen/offer to screen. In total, 97 (65%) of the cases had missed opportunities for early diagnosis and 57 (38%) had patient factors that likely contributed to the diagnostic delay or apparent failure to screen/offer to screen. Conclusion Missed opportunities for earlier CRC diagnosis were frequent. Additional studies of clinical data management, focusing on following

  10. Earlier Migration Timing, Decreasing Phenotypic Variation, and Biocomplexity in Multiple Salmonid Species

    PubMed Central

    Kovach, Ryan P.; Joyce, John E.; Echave, Jesse D.; Lindberg, Mark S.; Tallmon, David A.

    2013-01-01

    Climate-induced phenological shifts can influence population, evolutionary, and ecological dynamics, but our understanding of these phenomena is hampered by a lack of long-term demographic data. We use a multi-decade census of 5 salmonid species representing 14 life histories in a warming Alaskan stream to address the following key questions about climate change and phenology: How consistent are temporal patterns and drivers of phenology for similar species and alternative life histories? Are shifts in phenology associated with changes in phenotypic variation? How do phenological changes influence the availability of resource subsidies? For most salmonid species, life stages, and life histories, freshwater temperature influences migration timing – migration events are occurring earlier in time (mean = 1.7 days earlier per decade over the 3–5 decades), and the number of days over which migration events occur is decreasing (mean = 1.5 days per decade). Temporal trends in migration timing were not correlated with changes in intra-annual phenotypic variation, suggesting that these components of the phenotypic distribution have responded to environmental change independently. Despite commonalities across species and life histories, there was important biocomplexity in the form of disparate shifts in migration timing and variation in the environmental factors influencing migration timing for alternative life history strategies in the same population. Overall, adult populations have been stable during these phenotypic and environmental changes (λ ≈1.0), but the temporal availability of salmon as a resource in freshwater has decreased by nearly 30 days since 1971 due to changes in the median date of migration timing and decreases in intra-annual variation in migration timing. These novel observations advance our understanding of phenological change in response to climate warming, and indicate that climate change has influenced the ecology of salmon

  11. Midlife adiposity predicts earlier onset of Alzheimer's dementia, neuropathology and presymptomatic cerebral amyloid accumulation.

    PubMed

    Chuang, Y-F; An, Y; Bilgel, M; Wong, D F; Troncoso, J C; O'Brien, R J; Breitner, J C; Ferruci, L; Resnick, S M; Thambisetty, M

    2016-07-01

    Understanding how midlife risk factors influence age at onset (AAO) of Alzheimer's disease (AD) may provide clues to delay disease expression. Although midlife adiposity predicts increased incidence of AD, it is unclear whether it affects AAO and severity of Alzheimer's neuropathology. Using a prospective population-based cohort, Baltimore Longitudinal Study of Aging (BLSA), this study aims to examine the relationships between midlife body mass index (BMI) and (1) AAO of AD (2) severity of Alzheimer's neuropathology and (3) fibrillar brain amyloid deposition during aging. We analyzed data on 1394 cognitively normal individuals at baseline (8643 visits; average follow-up interval 13.9 years), among whom 142 participants developed incident AD. In two subsamples of BLSA, 191 participants underwent autopsy and neuropathological assessment, and 75 non-demented individuals underwent brain amyloid imaging. Midlife adiposity was derived from BMI data at 50 years of age. We find that each unit increase in midlife BMI predicts earlier onset of AD by 6.7 months (P=0.013). Higher midlife BMI was associated with greater Braak neurofibrillary but not CERAD (Consortium to Establish a Registry for Alzheimer's Disease) neuritic plaque scores at autopsy overall. Associations between midlife BMI and brain amyloid burden approached statistical significance. Thus, higher midlife BMI was also associated with greater fibrillar amyloid measured by global mean cortical distribution volume ratio (P=0.075) and within the precuneus (left, P=0.061; right, P=0.079). In conclusion, midlife overweight predicts earlier onset of AD and greater burden of Alzheimer's neuropathology. A healthy BMI at midlife may delay the onset of AD.

  12. The MEST score provides earlier risk prediction in lgA nephropathy.

    PubMed

    Barbour, Sean J; Espino-Hernandez, Gabriela; Reich, Heather N; Coppo, Rosanna; Roberts, Ian S D; Feehally, John; Herzenberg, Andrew M; Cattran, Daniel C

    2016-01-01

    The Oxford Classification of IgA nephropathy (IgAN) includes the following four histologic components: mesangial (M) and endocapillary (E) hypercellularity, segmental sclerosis (S) and interstitial fibrosis/tubular atrophy (T). These combine to form the MEST score and are independently associated with renal outcome. Current prediction and risk stratification in IgAN requires clinical data over 2 years of follow-up. Using modern prediction tools, we examined whether combining MEST with cross-sectional clinical data at biopsy provides earlier risk prediction in IgAN than current best methods that use 2 years of follow-up data. We used a cohort of 901 adults with IgAN from the Oxford derivation and North American validation studies and the VALIGA study followed for a median of 5.6 years to analyze the primary outcome (50% decrease in eGFR or ESRD) using Cox regression models. Covariates of clinical data at biopsy (eGFR, proteinuria, MAP) with or without MEST, and then 2-year clinical data alone (2-year average of proteinuria/MAP, eGFR at biopsy) were considered. There was significant improvement in prediction by adding MEST to clinical data at biopsy. The combination predicted the outcome as well as the 2-year clinical data alone, with comparable calibration curves. This effect did not change in subgroups treated or not with RAS blockade or immunosuppression. Thus, combining the MEST score with cross-sectional clinical data at biopsy provides earlier risk prediction in IgAN than our current best methods. PMID:26759049

  13. Business Education Curriculum. Revised.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education, Juneau. Div. of Adult and Vocational Education.

    This revised curriculum gives information on the skills and knowledge students should acquire through a business education program. The competencies listed reflect the skills that employers see as necessary for success in clerical and accounting occupations. The handbook is organized in seven sections that cover the following: (1) the concept of…

  14. AGRICOLA User's Guide. [Revised].

    ERIC Educational Resources Information Center

    Gilreath, Charles L.

    This document is the newest revision of the third manual documenting the National Agricultural Library database. Since it began in 1970, the AGRICOLA database has continued to grow and to change steadily; new subfiles have been added, database record formats have been expanded, and subject category code schemes have been modified several times.…

  15. What Research Says about Revision.

    ERIC Educational Resources Information Center

    Gentry, Larry A.

    The process, content, and effect of revision in the writing process is analyzed in light of recent writing process research. Taylor calls for an approach to English as second language composition in which students are taught how to write with an emphasis on revision. Most authorities agree that revision entails a complex set of behaviors that…

  16. The hydro-climatic history of the Gulf of Cadiz throughout the last ~570 kyr from IODP 339 Site U1386

    NASA Astrophysics Data System (ADS)

    Kaboth, Stefanie; de Boer, Bas; Bahr, Andrè; Zeeden, Christian; Lourens, Lucas

    2016-04-01

    Here we present the first continuous and high-resolution (~ 1 kyr) benthic δ18O record from IODP Site U1386 (Gulf of Cadiz, IODP Exp. 339) representing the last 570 kyr. We find distinct and periodic δ18O enrichment events overimposed on patterns of global ice volume change as inferred from the global mean δ18O signal (i.e. LR04). These events occur most prominently during glacials, and are characterized by a relative increase of up to 1‰. The observed glacial δ18O enrichment represents a striking difference to deep-sea benthic δ18O records worldwide but is not without precedent as similar δ18O variability can be observed in the planktic signal of the Red Sea (Sites KL11 and KL23). There, similar glacial δ18O enrichment events have not raised particular interest since their occurrence was attributed to sea level induced salinity increase within this virtually landlocked basin. Our results suggest that the glacial δ18O enrichment at Site U1386 present salinity and/or temperature variability related to changes in the position of the frontal zone between subpolar and subtropical water masses within the Gulf of Cadiz. Interestingly, the δ18O enrichments at Site U1386 strongly reflect precession and semi-precession patterns. Since similar patterns can be observed in the Red Sea isotopic records, we argue that part of the inferred sea level reconstructions are biased by a regional and precession controlled mechanism.

  17. An 80 kyr-long continuous speleothem record from Dim Cave, SW Turkey with paleoclimatic implications for the Eastern Mediterranean.

    PubMed

    Ünal-İmer, Ezgi; Shulmeister, James; Zhao, Jian-Xin; Uysal, I Tonguç; Feng, Yue-Xing; Nguyen, Ai Duc; Yüce, Galip

    2015-01-01

    Speleothem-based stable isotope records are valuable in sub-humid and semi-arid settings where many other terrestrial climate proxies are fragmentary. The Eastern Mediterranean is one such region. Here we present an 80-kyr-long precisely-dated (by U-series) and high-resolution oxygen (δ(18)O) and carbon (δ(13)C) records from Dim Cave (~36°N) in SW Turkey. The glacial-interglacial δ(18)O variations in the Dim Cave speleothem are best explained in terms of changes in the trajectories of winter westerly air masses. These are along a northerly (European) track (isotopically less depleted) during the early last glaciation but are gradually depressed southward closer to the modern westerly track along the North African coast (more depleted) after c.50 kyr and remain in the southern track through the Last Glacial Maximum. The southward displacement of the westerly track reflects growth of the Fennoscandian ice sheet and its impact on westerly wind fields. Changes in δ(13)C are interpreted as reflecting soil organic matter composition and/or thickness. δ(13)C values are significantly more negative in interglacials reflecting active carbonic acid production in the soil and less negative in glacial times reflecting carbonate rock values. Several Heinrich events are recorded in the Dim record indicating intensification of westerly flow across this part of the EM.

  18. Bulk and Compound-Specific Isotope Analysis of Long-Chain, n-alkanes From a 85-kyr Core From Lake Peten Itza, Guatemala

    NASA Astrophysics Data System (ADS)

    Mays, J. L.; Brenner, M.; Bush, M. B.; Correa, A.; Curtis, J. H.; Hodell, D. A.

    2007-12-01

    Drill cores obtained from Lake Petén Itzá, Guatemala, contain a ~85-kyr record of terrestrial climate from lowland Central America. Variations in sediment lithology suggest rapid changes in precipitation during the last glacial and deglacial periods. Previous work in nearby Lake Quexil demonstrated the utility of using the carbon isotopic compositions of leaf wax n-alkanes to infer changes in terrestrial vegetation (Huang et al., 2001). Here we report carbon isotopes of bulk organic and long-chain n-alkanes in 60 samples to reconstruct changes in the relative proportion of C3 and C4 biomass in the watershed under changing climate and atmospheric CO2 conditions during the past 85 kyrs. Compound-specific carbon isotope results are compared directly with pollen analysis from the same samples. Huang, Y., F.A. Street-Perrott, S.E. Metcalfe, M. Brenner, M. Moreland, and K.H. Freeman. 2001. Climate change as the dominant control on glacial-interglacial variations in C3 and C4 plant abundance. Science 293:1647-1651.

  19. An 80 kyr-long continuous speleothem record from Dim Cave, SW Turkey with paleoclimatic implications for the Eastern Mediterranean

    PubMed Central

    Ünal-İmer, Ezgi; Shulmeister, James; Zhao, Jian-Xin; Tonguç Uysal, I.; Feng, Yue-Xing; Duc Nguyen, Ai; Yüce, Galip

    2015-01-01

    Speleothem-based stable isotope records are valuable in sub-humid and semi-arid settings where many other terrestrial climate proxies are fragmentary. The Eastern Mediterranean is one such region. Here we present an 80-kyr-long precisely-dated (by U-series) and high-resolution oxygen (δ18O) and carbon (δ13C) records from Dim Cave (~36°N) in SW Turkey. The glacial-interglacial δ18O variations in the Dim Cave speleothem are best explained in terms of changes in the trajectories of winter westerly air masses. These are along a northerly (European) track (isotopically less depleted) during the early last glaciation but are gradually depressed southward closer to the modern westerly track along the North African coast (more depleted) after c.50 kyr and remain in the southern track through the Last Glacial Maximum. The southward displacement of the westerly track reflects growth of the Fennoscandian ice sheet and its impact on westerly wind fields. Changes in δ13C are interpreted as reflecting soil organic matter composition and/or thickness. δ13C values are significantly more negative in interglacials reflecting active carbonic acid production in the soil and less negative in glacial times reflecting carbonate rock values. Several Heinrich events are recorded in the Dim record indicating intensification of westerly flow across this part of the EM. PMID:26337921

  20. Man the Fat Hunter: The Demise of Homo erectus and the Emergence of a New Hominin Lineage in the Middle Pleistocene (ca. 400 kyr) Levant

    PubMed Central

    Ben-Dor, Miki; Gopher, Avi; Hershkovitz, Israel; Barkai, Ran

    2011-01-01

    The worldwide association of H. erectus with elephants is well documented and so is the preference of humans for fat as a source of energy. We show that rather than a matter of preference, H. erectus in the Levant was dependent on both elephants and fat for his survival. The disappearance of elephants from the Levant some 400 kyr ago coincides with the appearance of a new and innovative local cultural complex – the Levantine Acheulo-Yabrudian and, as is evident from teeth recently found in the Acheulo-Yabrudian 400-200 kyr site of Qesem Cave, the replacement of H. erectus by a new hominin. We employ a bio-energetic model to present a hypothesis that the disappearance of the elephants, which created a need to hunt an increased number of smaller and faster animals while maintaining an adequate fat content in the diet, was the evolutionary drive behind the emergence of the lighter, more agile, and cognitively capable hominins. Qesem Cave thus provides a rare opportunity to study the mechanisms that underlie the emergence of our post-erectus ancestors, the fat hunters. PMID:22174868

  1. An 80 kyr-long continuous speleothem record from Dim Cave, SW Turkey with paleoclimatic implications for the Eastern Mediterranean.

    PubMed

    Ünal-İmer, Ezgi; Shulmeister, James; Zhao, Jian-Xin; Uysal, I Tonguç; Feng, Yue-Xing; Nguyen, Ai Duc; Yüce, Galip

    2015-01-01

    Speleothem-based stable isotope records are valuable in sub-humid and semi-arid settings where many other terrestrial climate proxies are fragmentary. The Eastern Mediterranean is one such region. Here we present an 80-kyr-long precisely-dated (by U-series) and high-resolution oxygen (δ(18)O) and carbon (δ(13)C) records from Dim Cave (~36°N) in SW Turkey. The glacial-interglacial δ(18)O variations in the Dim Cave speleothem are best explained in terms of changes in the trajectories of winter westerly air masses. These are along a northerly (European) track (isotopically less depleted) during the early last glaciation but are gradually depressed southward closer to the modern westerly track along the North African coast (more depleted) after c.50 kyr and remain in the southern track through the Last Glacial Maximum. The southward displacement of the westerly track reflects growth of the Fennoscandian ice sheet and its impact on westerly wind fields. Changes in δ(13)C are interpreted as reflecting soil organic matter composition and/or thickness. δ(13)C values are significantly more negative in interglacials reflecting active carbonic acid production in the soil and less negative in glacial times reflecting carbonate rock values. Several Heinrich events are recorded in the Dim record indicating intensification of westerly flow across this part of the EM. PMID:26337921

  2. Reconstruction of surface water conditions in the central region of the Okhotsk Sea during the last 180 kyrs

    NASA Astrophysics Data System (ADS)

    Khim, Boo-Keun; Sakamoto, Tatsuhiko; Harada, Naomi

    2012-02-01

    Core GC9A, a 6.7 m long gravity core collected from the central region of the Okhotsk Sea during Cruise YK0712 on R/V Yokosuka (JAMSTEC), was used to reconstruct the changes in surface water conditions by measuring biogenic components (biogenic opal, CaCO3, total organic carbon and δ15N of sediment organic matter) of sediment samples. The age of Core GC9A was determined indirectly by graphic correlation comparing the b* (psychometric yellow-blue chromaticness) values with those of well-dated Core MD01-2415, with complement to the tephra layer (K3; 50 ka). The bottom age of Core GC9A was estimated to be about 180 kyr; therefore it provides the history of surface water conditions from MIS 1 to MIS 6. The biogenic opal, CaCO3, and TOC contents were high during the interglacial periods as expected, indicating enhanced surface water production under warm climatic conditions. This condition resulted from sufficient nutrient supply to the surface waters by active vertical mixing, which was validated by low δ15N values of the sediment organic matter. In contrast, surface water productivity was depressed during the colder glacial periods, probably due to the expanded sea-ice distribution and limited nutrient supply. However, the glacial sediments had moderately high δ15N values, indicating enhanced nitrate utilization resulting from the limited nutrient supply caused by strong stratification of the surface water. High δ15N values were also observed during the deglaciation, which was attributed to the increased nitrate utilization during enhanced surface water productivity. However, the low δ15N values during the glacial and deglacial periods may be attributed to the increased supply of terrestrial organic matter. Diatom production was primarily responsible for surface water paleoproductivity during the interglacial periods rather than coccolithophores. However, the succession of glacial to early deglacial coccolithophore production and late deglacial to interglacial

  3. Biogeochemistry of mineral-organic associations across a long-term mineralogical soil gradient (0.3-4100 kyr), Hawaiian Islands

    NASA Astrophysics Data System (ADS)

    Mikutta, Robert; Schaumann, Gabriele E.; Gildemeister, Daniela; Bonneville, Steeve; Kramer, Marc G.; Chorover, Jon; Chadwick, Oliver A.; Guggenberger, Georg

    2009-04-01

    Organic matter (OM) in mineral-organic associations (MOAs) represents a large fraction of carbon in terrestrial ecosystems which is considered stable against biodegradation. To assess the role of MOAs in carbon cycling, there is a need to better understand (i) the time-dependent biogeochemical evolution of MOAs in soil, (ii) the effect of the mineral composition on the physico-chemical properties of attached OM, and (iii) the resulting consequences for the stabilization of OM. We studied the development of MOAs across a mineralogical soil gradient (0.3-4100 kyr) at the Hawaiian Islands that derived from basaltic tephra under comparable climatic and hydrological regimes. Mineral-organic associations were characterized using biomarker analyses of OM with chemolytic methods (lignin phenols, non-cellulosic carbohydrates) and wet chemical extractions, surface area/porosity measurements (N 2 at 77 K and CO 2 at 273 K), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and differential scanning calorimetry (DSC). The results show that in the initial weathering stage (0.3 kyr), MOAs are mainly composed of primary, low-surface area minerals (olivine, pyroxene, feldspar) with small amounts of attached OM and lignin phenols but a large contribution of microbial-derived carbohydrates. As high-surface area, poorly crystalline (PC) minerals increase in abundance during the second weathering stage (20-400 kyr), the content of mineral-associated OM increased sharply, up to 290 mg C/g MOA, with lignin phenols being favored over carbohydrates in the association with minerals. In the third and final weathering stage (1400-4100 kyr), metastable PC phases transformed into well crystalline secondary Fe and Al (hydr)oxides and kaolin minerals that were associated with less OM overall, and depleted in both lignin and carbohydrate as a fraction of total OM. XPS, the N 2 pore volume data and OM-mineral volumetric ratios suggest that, in contrast to the

  4. Low forced expiratory volume is associated with earlier death in sickle cell anemia.

    PubMed

    Kassim, Adetola A; Payne, Amanda B; Rodeghier, Mark; Macklin, Eric A; Strunk, Robert C; DeBaun, Michael R

    2015-09-24

    Pulmonary complications result in mortality in adults with sickle cell anemia (SCA). We tested the hypothesis that abnormal pulmonary function was associated with earlier death. A prospective cohort of adults with SCA, followed in the Cooperative Study for Sickle Cell Disease, was constructed using the first pulmonary function test at >21 years of age. Spirometry measures: forced expiratory volume in 1 second (FEV1), forced vital capacity, and total lung capacity were categorized based on age, gender, height, and race. Pulmonary function patterns were categorized based on the American Thoracic Society guidelines using both spirometry and lung volumes. A cohort of 430 adults with SCA, mean age 32.6 ± 9.5 (range, 21.0-67.8) years at time of first pulmonary function test, and a median follow-up of 5.5 years, was evaluated. A total of 63 deaths occurred. At baseline, 47% had normal, 29% restrictive, 8% obstructive, 2% mixed, and 14% nonspecific lung function patterns. In the final multivariable model, lower FEV1 percent predicted was associated with increased hazard ratio of death (HR per % predicted 1.02; 95% confidence interval [CI] 1.00-1.04; P = .037), as was older age (HR 1.07; 95% CI 1.04-1.10; P < .001), male sex (HR 2.09; 95% CI 1.20-3.65; P = .010), higher lactate dehydrogenase levels (HR per mg/dL 1.002; 95% CI 1.00-1.003; P = .015), and higher acute chest syndrome incidence rate (HR per event/year 10.4; 95% CI 3.11-34.8; P < .001). Presence of obstructive (HR 1.18; 95% CI: 0.44-3.20; P = .740) and restrictive (HR 1.31; 95% CI: 0.64-2.32; P = .557) pulmonary function patterns were not associated with earlier death. Understanding the pathophysiology of a low FEV1 percent predicted in individuals with SCA is warranted, enabling early intervention for those at risk. PMID:26261241

  5. Motivation before meaning: motivational information encoded in meerkat alarm calls develops earlier than referential information.

    PubMed

    Hollén, Linda I; Manser, Marta B

    2007-06-01

    In contrast to historical assumptions about the affective nature of animal vocalizations, it is now clear that many vertebrates are capable of producing specific alarm calls in response to different predators, calls that provide information that goes beyond the motivational state of a caller. However, although these calls function referentially, it does not mean that they are devoid of motivational content. Studies on meerkats (Suricata suricatta) directly support this conclusion. The acoustic structure of their alarm calls simultaneously encodes information that is both motivational (level of urgency) and referential (predator specific). In this study, we investigated whether alarm calls of young meerkats undergo developmental modification and whether the motivational or the referential aspect of calls changes more over time. We found that, based on their acoustic structure, calls of young showed a high correct assignment to low- and high-urgency contexts but, in contrast to adults, low assignment to specific predator types. However, the discrimination among predator types was better in high-urgency than in low-urgency contexts. Our results suggest that acoustic features related to level of urgency are expressed earlier than those related to predator-specific information and may support the idea that referential calls evolve from motivational signals.

  6. Change in the cortical complexity of spinocerebellar ataxia type 3 appears earlier than clinical symptoms.

    PubMed

    Wang, Tzu-Yun; Jao, Chii-Wen; Soong, Bing-Wen; Wu, Hsiu-Mei; Shyu, Kuo-Kai; Wang, Po-Shan; Wu, Yu-Te

    2015-01-01

    Patients with spinocerebellar ataxia type 3 (SCA3) have exhibited cerebral cortical involvement and various mental deficits in previous studies. Clinically, conventional measurements, such as the Mini-Mental State Examination (MMSE) and electroencephalography (EEG), are insensitive to cerebral cortical involvement and mental deficits associated with SCA3, particularly at the early stage of the disease. We applied a three-dimensional fractal dimension (3D-FD) method, which can be used to quantify the shape complexity of cortical folding, in assessing cortical degeneration. We evaluated 48 genetically confirmed SCA3 patients by employing clinical scales and magnetic resonance imaging and using 50 healthy participants as a control group. According to the Scale for the Assessment and Rating of Ataxia (SARA), the SCA3 patients were diagnosed with cortical dysfunction in the cerebellar cortex; however, no significant difference in the cerebral cortex was observed according to the patients' MMSE ratings. Using the 3D-FD method, we determined that cortical involvement was more extensive than involvement of traditional olivopontocerebellar regions and the corticocerebellar system. Moreover, the significant correlation between decreased 3D-FD values and disease duration may indicate atrophy of the cerebellar cortex and cerebral cortex in SCA3 patients. The change of the cerebral complexity in the SCA3 patients can be detected throughout the disease duration, especially it becomes substantial at the late stage of the disease. Furthermore, we determined that atrophy of the cerebral cortex may occur earlier than changes in MMSE scores and EEG signals.

  7. Earlier springs are causing reduced nitrogen availability in North American eastern deciduous forests.

    PubMed

    Elmore, Andrew J; Nelson, David M; Craine, Joseph M

    2016-01-01

    There is wide agreement that anthropogenic climate warming has influenced the phenology of forests during the late twentieth and early twenty-first centuries(1,2). Longer growing seasons can lead to increased photosynthesis and productivity(3), which would represent a negative feedback to rising CO2 and consequently warming(4,5). Alternatively, increased demand for soil resources because of a longer photosynthetically active period in conjunction with other global change factors might exacerbate resource limitation(6,7), restricting forest productivity response to a longer growing season(8,9). In this case, increased springtime productivity has the potential to increase plant nitrogen limitation by increasing plant demand for nitrogen more than nitrogen supplies, or increasing early-season ecosystem nitrogen losses(10,11). Here we show that for 222 trees representing three species in eastern North America earlier spring phenology during the past 30 years has caused declines in nitrogen availability to trees by increasing demand for nitrogen relative to supply. The observed decline in nitrogen availability is not associated with reduced wood production, suggesting that other environmental changes such as increased atmospheric CO2 and water availability are likely to have overwhelmed reduced nitrogen availability. Given current trajectories of environmental changes, nitrogen limitation is likely to continue to increase for these forests, possibly further limiting carbon sequestration potential. PMID:27618399

  8. Towards earlier inclusion of Children in Tuberculosis (TB) drugs trials: Consensus statements from an Expert Panel

    PubMed Central

    Nachman, Sharon; Ahmed, Amina; Amanullah, Farhana; Becerra, Mercedes C; Botgros, Radu; Brigden, Grania; Browning, Renee; Gardiner, Elizabeth; Hafner, Richard; Hesseling, Anneke; How, Cleotilde; Jean-Philippe, Patrick; Lessem, Erica; Makhene, Mamodikoe; Mbelle, Nontombi; Marais, Ben; McIlleron, Helen; Mc Neeley, David F; Mendel, Carl; Murray, Stephen; Navarro, Eileen; Oramasionwu, Gloria E; Porcalla, Ariel R; Powell, Clydette; Powell, Mair; Rigaud, Mona; Rouzier, Vanessa; Samson, Pearl; Schaaf, H. Simon; Shah, Seema; Starke, Jeff; Swaminathan, Soumya; Wobudeya, Eric; Worrell, Carol

    2015-01-01

    Children represent a significant proportion of the global tuberculosis (TB) burden, and may be disproportionately more affected by its most severe clinical manifestations. Currently available treatments for pediatric drug-susceptible (DS) and drug-resistant (DR) TB, albeit generally effective, are hampered by high pill burden, long duration of treatment, coexistent toxicities, and an overall lack of suitable, child-friendly formulations. The complex and burdensome nature of administering the existing regimens to treat DS TB also contributes to the rise of DR TB strains. Despite the availability and use of these therapies for decades, a dearth of dosing evidence in children underscores the importance of sustained efforts for TB drug development to better meet the treatment needs of children with TB. Several new TB drugs and regimens with promising activity against both DS and DR TB strains have recently entered clinical development and are in various phases of clinical evaluation in adults or have received marketing authorization for adults. However, initiation of clinical trials to evaluate these drugs in children is often deferred, pending the availability of complete safety and efficacy data in adults or after drug approval. This document summarizes consensus statements from an international panel of childhood TB opinion leaders which support the initiation of evaluation of new TB drugs and regimens in children at earlier phases of the TB Drug development cycle. PMID:25957923

  9. The response of aboveground plant productivity to earlier snowmelt and summer warming in an Arctic ecosystem

    NASA Astrophysics Data System (ADS)

    Livensperger, C.; Steltzer, H.; Darrouzet-Nardi, A.; Sullivan, P.; Wallenstein, M. D.; Weintraub, M. N.

    2012-12-01

    Plant communities in the Arctic are undergoing changes in structure and function due to shifts in seasonality from changing winters and summer warming. These changes will impact biogeochemical cycling, surface energy balance, and functioning of vertebrate and invertebrate communities. To examine seasonal controls on aboveground net primary production (ANPP) in a moist acidic tundra ecosystem in northern Alaska, we shifted the growing season by accelerating snowmelt (using radiation absorbing shadecloth) and warming air and soil temperature (using 1 m2 open-top chambers), individually and in combination. After three years, we measured ANPP by harvesting up to 16 individual ramets, tillers and rhizomes for each of 7 plant species, including two deciduous shrubs, two graminoids, two evergreen shrubs and one forb during peak season. Our results show that ANPP per stem summed across the 7 species increased when snow melt occurred earlier. However, standing biomass, excluding current year growth, was also greater. The ratio of ANPP/standing biomass decreased in all treatments compared to the control. ANPP per unit standing biomass summed for the four shrub species decreases due to summer warming alone or in combination with early snowmelt; however early snowmelt alone did not lead to lower ANPP for the shrubs. ANPP per tiller or rhizome summed for the three herbaceous species increased in response to summer warming. Understanding the differential response of plants to changing seasonality will inform predictions of future Arctic plant community structure and function.

  10. Earlier springs are causing reduced nitrogen availability in North American eastern deciduous forests.

    PubMed

    Elmore, Andrew J; Nelson, David M; Craine, Joseph M

    2016-09-12

    There is wide agreement that anthropogenic climate warming has influenced the phenology of forests during the late twentieth and early twenty-first centuries(1,2). Longer growing seasons can lead to increased photosynthesis and productivity(3), which would represent a negative feedback to rising CO2 and consequently warming(4,5). Alternatively, increased demand for soil resources because of a longer photosynthetically active period in conjunction with other global change factors might exacerbate resource limitation(6,7), restricting forest productivity response to a longer growing season(8,9). In this case, increased springtime productivity has the potential to increase plant nitrogen limitation by increasing plant demand for nitrogen more than nitrogen supplies, or increasing early-season ecosystem nitrogen losses(10,11). Here we show that for 222 trees representing three species in eastern North America earlier spring phenology during the past 30 years has caused declines in nitrogen availability to trees by increasing demand for nitrogen relative to supply. The observed decline in nitrogen availability is not associated with reduced wood production, suggesting that other environmental changes such as increased atmospheric CO2 and water availability are likely to have overwhelmed reduced nitrogen availability. Given current trajectories of environmental changes, nitrogen limitation is likely to continue to increase for these forests, possibly further limiting carbon sequestration potential.

  11. Motivation before meaning: motivational information encoded in meerkat alarm calls develops earlier than referential information.

    PubMed

    Hollén, Linda I; Manser, Marta B

    2007-06-01

    In contrast to historical assumptions about the affective nature of animal vocalizations, it is now clear that many vertebrates are capable of producing specific alarm calls in response to different predators, calls that provide information that goes beyond the motivational state of a caller. However, although these calls function referentially, it does not mean that they are devoid of motivational content. Studies on meerkats (Suricata suricatta) directly support this conclusion. The acoustic structure of their alarm calls simultaneously encodes information that is both motivational (level of urgency) and referential (predator specific). In this study, we investigated whether alarm calls of young meerkats undergo developmental modification and whether the motivational or the referential aspect of calls changes more over time. We found that, based on their acoustic structure, calls of young showed a high correct assignment to low- and high-urgency contexts but, in contrast to adults, low assignment to specific predator types. However, the discrimination among predator types was better in high-urgency than in low-urgency contexts. Our results suggest that acoustic features related to level of urgency are expressed earlier than those related to predator-specific information and may support the idea that referential calls evolve from motivational signals. PMID:17479462

  12. Newer drugs and earlier treatment: Impact on lifetime cost of care for HIV-infected adults

    PubMed Central

    Sloan, C.E.; Champenois, K.; Choisy, P.; Losina, E.; Walensky, R.P.; Schackmanj, B.R.; Ajana, F.; Melliez, H.; Paltiel, A.D.; Freedberg, K.A.

    2011-01-01

    Objective To determine the component costs of care to optimize treatment with limited resources. Design We used the Cost-Effectiveness of Preventing AIDS Complications Model of HIV disease and treatment to project life expectancy (LE) and both undiscounted and discounted lifetime costs (2010€). Methods We determined medical resource utilization among HIV-infected adults followed from 1998 to 2005 in Northern France. Monthly HIV costs were stratified by CD4 count. Costs of CD4, HIV RNA and genotype tests and antiretroviral therapy (ART) were derived from published literature. Model inputs from national data included mean age 38 years, mean initial CD4 count 372/µl, ART initiation at CD4 counts <350/µl, and ART regimen costs ranging from €760/month to €2,570/month. Results The model projected a mean undiscounted LE of 26.5 years and a lifetime undiscounted cost of €535,000/patient (€320,700 discounted); 73% of costs were ART-related. When patients presented to care with mean CD4 counts of 510/µl and initiated ART at CD4 counts <500/µl or HIV RNA >100,000 copies/ml, LE was 27.4 years and costs increased 1–2%, to €546,700 (€324,500 discounted). When we assumed introducing generic drugs would result in a 50% decline in first-line ART costs, lifetime costs decreased 4–6%, to €514,200 (€302,800 discounted). Conclusions As HIV disease is treated earlier with more efficacious drugs, survival and thus costs of care will continue to increase. The availability in high-income countries of widely-used antiretroviral drugs in generic form could reduce these costs. PMID:22008655

  13. NPH Log: Validation of a New Assessment Tool Leading to Earlier Diagnosis of Normal Pressure Hydrocephalus

    PubMed Central

    Lu, Jennifer; Robison, Jamie; Hoffberger, Jamie B; Hulbert, Alicia; Sanyal, Abanti; Wemmer, Jan; Elder, Benjamin D; Rigamonti, Daniele

    2016-01-01

    Introduction: Early treatment of normal pressure hydrocephalus (NPH) yields better postoperative outcomes. Our current tests often fail to detect significant changes at early stages. We developed a new scoring system (LP log score) to determine if this tool is more sensitive in detecting clinical differences than current tests. Material and Methods: Sixty-two consecutive new patients with suspected idiopathic NPH were studied. Secondary, previously treated and obstructive cases were not included. We collected age, pre- and post-lumbar puncture (LP) Tinetti, Timed Up and Go (TUG) Test, European NPH scale, and LP log scores. The LP log score is recorded at baseline and for seven consecutive days after removing 40 cc of cerebrospinal fluid (CSF) via LP. We studied the diagnostic accuracy of the tests for surgical indication. Results: The post-LP log showed improvement in 90% of people with good baseline gait tests and in 93% of people who did not show any pre-LP and post-LP change in gait tests. Sensitivity, specificity, and accuracy to detect intention to treat when positive post-LP improvements were 4%, 100%, and 24%, respectively, for TUG, 21%, 86%, and 34%, respectively, for the Tinetti Mobility Test, 66%, 29%, and 58%, respectively, for Medical College of Virginia (MCV) grade, and 98%, 33%, and 85%, respectively, for LP log score. Pre-LP and post-LP TUG improvement and pre-LP and post-LP Tinetti improvement were not associated with a surgical indication (p > 0.05). LP log improvement was associated with surgical indication odds ratio (OR): 24.5 95% CI (2.4-248.12) (p = 0.007). Conclusions: LP log showed better sensitivity, diagnostic accuracy, and association with surgical indication than the current diagnostic approach. An LP log may be useful detecting NPH patients at earlier stages and, therefore, yield better surgical outcomes. PMID:27489752

  14. Warming Mountains, Earlier runoff and Declining Snowpack in Western North America

    NASA Astrophysics Data System (ADS)

    Cayan, D. R.

    2015-12-01

    Climate changes, which will very likely mount over the next several decades, would add to a set of shifts that have appeared in snow and runoff during recent decades over western North America. Water from mountain snow has historically provided a vital portion of the water supply for the region, but warming since the mid-1970's has produced more rain, less snow, diminished snow accumulation and earlier runoff over mountain catchments that historically have accumulated significant snow cover. The observed warming and the hydrologic shifts have, with a high degree of likelihood, been boosted by additional anthropogenic warming. A many-member ensemble of CMIP5 GCM simulations indicates that even under moderate scenarios of rising greenhouse gases, the warming, relative to historical climatology, could approach +2°C by mid-21st Century. This amount of warming would produce substantial changes in watersheds which have historically been dominated by snowmelt. In the California Sierra Nevada, this warming would advance spring runoff timing by more than two weeks. Combined with changes towards increased precipitation amounts in the region's largest storms, higher than present-day freezing levels would increase flood flows in Sierran rivers. Historical observations and hydrological model simulations indicate that California's total spring snow water storage will decline by more than half by 2100. Heavy snow years would still occur, but not as often as today, and springs with highly depleted mountain snow pack would occur with increasing frequency. These changes would produce a cascade of impacts to natural landscapes and resources, requiring multifold adaptation strategies by the humans who use and are affected by them.

  15. Detection, attribution, and sensitivity of trends toward earlier streamflow in the Sierra Nevada

    USGS Publications Warehouse

    Maurer, E.P.; Stewart, I.T.; Bonfils, Celine; Duffy, P.B.; Cayan, D.

    2007-01-01

    Observed changes in the timing of snowmelt dominated streamflow in the western United States are often linked to anthropogenic or other external causes. We assess whether observed streamflow timing changes can be statistically attributed to external forcing, or whether they still lie within the bounds of natural (internal) variability for four large Sierra Nevada (CA) basins, at inflow points to major reservoirs. Streamflow timing is measured by "center timing" (CT), the day when half the annual flow has passed a given point. We use a physically based hydrology model driven by meteorological input from a global climate model to quantify the natural variability in CT trends. Estimated 50-year trends in CT due to natural climate variability often exceed estimated actual CT trends from 1950 to 1999. Thus, although observed trends in CT to date may be statistically significant, they cannot yet be statistically attributed to external influences on climate. We estimate that projected CT changes at the four major reservoir inflows will, with 90% confidence, exceed those from natural variability within 1-4 decades or 4-8 decades, depending on rates of future greenhouse gas emissions. To identify areas most likely to exhibit CT changes in response to rising temperatures, we calculate changes in CT under temperature increases from 1 to 5??. We find that areas with average winter temperatures between -2??C and -4??C are most likely to respond with significant CT shifts. Correspondingly, elevations from 2000 to 2800 in are most sensitive to temperature increases, with CT changes exceeding 45 days (earlier) relative to 1961-1990. Copyright 2007 by the American Geophysical Union.

  16. Earlier Arctic springs cause phenological mismatch in long-distance migrants.

    PubMed

    Clausen, Kevin Kuhlmann; Clausen, Preben

    2013-11-01

    An uneven change in climate across the Northern Hemisphere might severely affect the phenology of migrating animals, and especially long-distance migrating birds relying on local climatic cues to regulate the timing of migration. We examine the forward displacement of spring in both staging areas and breeding grounds of one such population, the East Atlantic light-bellied brent goose Branta bernicla hrota, and evaluate to what extent their migration has made a proportional response. On the breeding grounds in Svalbard the onset of spring advanced 2 weeks during the 24-year period, whereas no significant trend was found in the temperate staging areas. The timing of migration was constant throughout the study period, mirroring the static climatic conditions in the spring staging areas. These findings indicate a global warming-induced phenological mismatch in light-bellied brent geese, as these might arrive on their breeding grounds well beyond optimal breeding conditions. Our data indicated that productivity was negatively influenced by phenological delay and positively influenced by prolonged snow cover. We argue that both these effects might be representative of a negative influence of the growing phenological mismatch, because years with later thaw might partly offset the effects of increasingly earlier Svalbard springs. During the study period reproduction fell below annual mortality, and the population declined in recent years. The wider implications of these findings may extend to many migrating species, and highlight the urgent need to clarify how global change may influence cues and the associated timing of important life history activities. PMID:23660701

  17. Accelerated complications in Type 2 diabetes mellitus: the need for greater awareness and earlier detection.

    PubMed

    Muggeo, M

    1998-01-01

    Persistent hyperglycaemia is the underlying pathogenic factor responsible for chronic diabetic complications in Type 1 and Type 2 diabetes mellitus. In Type 1 diabetes, diagnosis is made soon after the onset of hyperglycaemia and several years are required for the resultant complications to appear clinically. The onset of Type 2 diabetes is insidious and is usually recognized only 5-12 years after hyperglycaemia develops. During this period of undiagnosed diabetes, hyperglycaemia, in combination with lifestyle factors (physical inactivity, alcohol use, smoking), and other metabolic (dyslipidaemia, obesity, insulin resistance) and haemodynamic (hypertension) abnormalities frequently associated with Type 2 diabetes, promote the initiation and progression of micro- and macrovascular complications. Furthermore, when blood glucose levels are increased only slightly and no symptoms are apparent, the physician may be reluctant to diagnose Type 2 diabetes or start treatment. This delay in diagnosing the disease results in a high prevalence of chronic complications at the time of actual diagnosis. Indeed, when Type 2 diabetes is diagnosed, cardiovascular disease and neuropathy are found in approximately 10% of cases, and retinopathy and nephropathy in 15-20%. All healthcare providers should be aware of this phenomenon, which may be termed 'accelerated complications', and should plan thorough screening programmes for these conditions at diagnosis. All reversible risk factors associated with diabetes should be identified and treated. When acute metabolic derangements and infections are not the main causes of morbidity and mortality in diabetes, the costs of diabetes care are related mainly to chronic complications of the disease. Therefore, because of the high frequency of Type 2 diabetes, the most efficient method of reducing costs is to increase awareness and secure earlier detection that leads to fast and aggressive treatment of the accelerated chronic complications often

  18. Endoplasmic reticulum stress induced by zinc oxide nanoparticles is an earlier biomarker for nanotoxicological evaluation.

    PubMed

    Chen, Rui; Huo, Lingling; Shi, Xiaofei; Bai, Ru; Zhang, Zhenjiang; Zhao, Yuliang; Chang, Yanzhong; Chen, Chunying

    2014-03-25

    Zinc oxide nanoparticles (ZnO NPs) have been widely used in cosmetics and sunscreens, advanced textiles, self-charging and electronic devices; the potential for human exposure and the health impact at each stage of their manufacture and use are attracting great concerns. In addition to pulmonary damage, nanoparticle exposure is also strongly correlated with the increase in incidences of cardiovascular diseases; however, their toxic potential remains largely unclear. Herein, we investigated the cellular responses and endoplasmatic reticulum (ER) stress induced by ZnO NPs in human umbilical vein endothelial cells (HUVECs) in comparison with the Zn2+ ions and CeO2 NPs. We found that the dissolved zinc ion was the most significant factor for cytotoxicity in HUVECs. More importantly, ZnO NPs at noncytotoxic concentration, but not CeO2 NPs, can induce significant cellular ER stress response with higher expression of spliced xbp-1, chop, and caspase-12 at the mRNA level, and associated ER marker proteins including BiP, Chop, GADD34, p-PERK, p-eIF2α, and cleaved Caspase-12 at the protein levels. Moreover, ER stress was widely activated after treatment with ZnO NPs, while six of 84 marker genes significantly increased. ER stress response is a sensitive marker for checking the interruption of ER homeostasis by ZnO NPs. Furthermore, higher dosage of ZnO NPs (240 μM) quickly rendered ER stress response before inducing apoptosis. These results demonstrate that ZnO NPs activate ER stress-responsive pathway and the ER stress response might be used as an earlier and sensitive end point for nanotoxicological study.

  19. Selection for earlier flowering crop associated with climatic variations in the Sahel.

    PubMed

    Vigouroux, Yves; Mariac, Cédric; De Mita, Stéphane; Pham, Jean-Louis; Gérard, Bruno; Kapran, Issoufou; Sagnard, Fabrice; Deu, Monique; Chantereau, Jacques; Ali, Abdou; Ndjeunga, Jupiter; Luong, Viviane; Thuillet, Anne-Céline; Saïdou, Abdoul-Aziz; Bezançon, Gilles

    2011-01-01

    Climate changes will have an impact on food production and will require costly adaptive responses. Adapting to a changing environment will be particularly challenging in sub-Saharan Africa where climate change is expected to have a major impact. However, one important phenomenon that is often overlooked and is poorly documented is the ability of agro-systems to rapidly adapt to environmental variations. Such an adaptation could proceed by the adoption of new varieties or by the adaptation of varieties to a changing environment. In this study, we analyzed these two processes in one of the driest agro-ecosystems in Africa, the Sahel. We performed a detailed study in Niger where pearl millet is the main crop and covers 65% of the cultivated area. To assess how the agro-system is responding to recent recurrent drought, we analyzed samples of pearl millet landraces collected in the same villages in 1976 and 2003 throughout the entire cultivated area of Niger. We studied phenological and morphological differences in the 1976 and 2003 collections by comparing them over three cropping seasons in a common garden experiment. We found no major changes in the main cultivated varieties or in their genetic diversity. However, we observed a significant shift in adaptive traits. Compared to the 1976 samples, samples collected in 2003 displayed a shorter lifecycle, and a reduction in plant and spike size. We also found that an early flowering allele at the PHYC locus increased in frequency between 1976 and 2003. The increase exceeded the effect of drift and sampling, suggesting a direct effect of selection for earliness on this gene. We conclude that recurrent drought can lead to selection for earlier flowering in a major Sahelian crop. Surprisingly, these results suggest that diffusion of crop varieties is not the main driver of short term adaptation to climatic variation. PMID:21573243

  20. Bilingual Children's Writing: Self-Correction and Revision of Written Narratives in Spanish and Nahuatl

    ERIC Educational Resources Information Center

    Francis, Norbert

    2005-01-01

    The article reports on findings from a replication of a study of bilingual children's editing and correction strategies. The earlier study analyzed revisions that 2nd, 4th, and 6th graders made to their own compositions, written in Spanish. The present study applied the same procedure and assessment rubric to the first draft of compositions…

  1. 75 FR 40726 - Revisions to the California State Implementation Plan, Sacramento Metropolitan Air Quality...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-14

    ... the SIP on May 4, 1999 (64 FR 23774). The SCAQMD adopted revisions to the SIP-approved version on... earlier version of SMAQMD Rule 456 was approved into the SIP on November 9, 1998 (63 FR 60214) and the... review by the Office of Management and Budget under Executive Order 12866 (58 FR 51735, October 4,...

  2. 78 FR 21542 - Revisions to the California State Implementation Plan, Santa Barbara County Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-11

    ... into the SIP on December 20, 2000 (65 FR 79752). We approved an earlier version of SCAQMD Rule 461 into the SIP on April 11, 2006 (71 FR 18216). The SCAQMD adopted revisions to the SIP-approved version on... review by the Office of Management and Budget under Executive Order 12866 (58 FR 51735, October 4,...

  3. 77 FR 2469 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-18

    ... for Gas Turbines, Cement Kilns, Boilers, and Internal Combustion Engines,'' Northeast States for... (61 FR 56470). The AVAQMD adopted an earlier a revision to the SIP approved version of Rule 1134 on... monitoring period. (74 FR 63309) This determination suspended some of the planning requirements related...

  4. Dry Creek Joint Elementary School District. Educational Specifications: K-5 Permanent (Revised 1998).

    ERIC Educational Resources Information Center

    Dry Creek Joint Elementary School District, Roseville, CA.

    An Educational Specification Committee was convened to determine the design specifications required for a new K-5 (and temporarily 6-8 grade) elementary school in Roseville, California's Dry Creek District. This report presents revisions to an earlier document that examined school room specifications for each grade level and administrative area.…

  5. 77 FR 66780 - Revisions to the California State Implementation Plan, South Coast Air Quality Management District

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-07

    ... earlier version of Rule 1113 into the SIP on August 17, 2011 (76 FR 50891). The SCAQMD adopted revisions... FR 51735, October 4, 1993); does not impose an information collection burden under the provisions of... Federalism implications as specified in Executive Order 13132 (64 FR 43255, August 10, 1999); is not...

  6. 78 FR 45114 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-26

    ... of these rules? We approved an earlier version of Rule 218 into the SIP on September 2, 2008 (73 FR... of Rule 431.1 into the SIP on October 19, 1984 (49 FR 41028).\\1\\ AVAQMD adopted revisions to Rule 431..., and Deviations,'' EPA, May 25, 1988 (the Bluebook). 2. ``Guidance Document for Correcting Common...

  7. A Revised FORTRAN IV Program for Three-mode Factor Analysis

    ERIC Educational Resources Information Center

    Walsh, James A.; Walsh, Roberta

    1976-01-01

    This Fortran IV revision of an earlier three-mode factor analysis program uses a main program-subprogram structure and core storage and is written in a sufficiently general form as to be easily convertable to most machines having a Fortran IV compiler. (RC)

  8. Glacial-Interglacial sea level reconstruction of the last 570 kyr: Inferences from a new benthic δ18O record of IODP Site U1386 (Gulf of Cadiz)

    NASA Astrophysics Data System (ADS)

    Kaboth, S.; Lourens, L. J.; de Boer, B.

    2015-12-01

    Sea level reconstructions on geological time scales are crucial for our understanding of glacial-interglacial cycles in the past, and thus offer context for current and projected changes. Global sea-level variations since the last glacial maximum have been well established based on numerous well-dated coral reef terraces and speleothem records. Throughout the Late Pleistocene, the coral and speleothem based data sets become more incomplete and reliable dated sea-level points, though showing the general amplitude of sea-level changes, are insufficient to establish the exact pattern and timing of millennial-scale changes. To gain further insight into glacial-interglacial sea level variations throughout the Late Pleistocene, we generated a new benthic δ18O record of IODP Site U1386 in the Gulf of Cadiz for the past ~ 570 kyr. Site U1386 is located within the Gulf of Cadiz Contourite Depositional System (CDS). These sediments are characterized by high sedimentation rate (~35 cm/kyr), providing a unique opportunity to study sea level oscillations in high resolution. To estimate ice volume and deep-water temperature changes we used an inverse forward modeling approach based on our benthic δ18O data. The coupled model includes four ice-sheet-shelf components that simulate glaciation on Eurasia, North America, Greenland and Antarctica, thereby explicitly accounting for all individual ice-volume contributions throughout the investigated time period. Our initial findings suggest that older glacial periods were characterized by repeated and substantial δ18O enrichment events preceding their respective glacial maximum. We argue that the observed δ18O enrichment events are not an expression of local hydrographic changes of salinity and/or temperature limited to the Gulf of Cadiz but probably relate to global ice volume changes. In this regard, our results contrast estimates derived from the global mean benthic δ18O LR04 stack. On a regional scale, our results show

  9. What can we learn today from the Central European smog episode of 1985 (and earlier episodes)?

    PubMed

    Wichmann, H Erich

    2004-12-01

    In January 1985 an extended smog episode occurred in Central Europe. The Rhine-Ruhr area (Western Germany) was affected for 5 days with maximum concentrations of 0.8 mg/m3 SO2 and 0.6 mg/m3 TSP (24h averages). Health effects were investigated during the smog period and a control period before and after the smog. Daily mortality increased by 8%, hospital admissions (for respiratory and cardiovascular causes, RC) by 15%, outpatients (RC) by 12% and ambulance transports (RC) by 28%. Patients with chronic bronchitis from the Ruhr area cities showed more exacerbations during the episode, and in school children from the Netherlands lung function was reduced. In Augsburg (Southern Germany) the smog episode was less severe (maximum concentrations 0.2 mg/m3 SO2 and 0.1 mg/m3 TSP, 24 h averages). Here--by chance--the prospective MONICA study was ongoing. During the episode a significant increase of plasma viscosity, C-reactive protein and heart rate was observed in the participants. The highest ambient concentrations (maximum 24h average of 3.6 mg/m3 SO2) were measured in Erfurt (Eastern Germany). Surprisingly, no measurable increase of mortality occurred. This was explained by premature deaths during the period before the smog, were the concentrations had already been clearly above 1 mg/m3 SO2. An earlier episode took place in December 1962 in the Rhine-Ruhr area for 5 days with maximum concentrations of 5.0 mg/m3 SO2 and 2.4 mg/m3 TSP (24 h average). Daily mortality on average increased by 19%. In 1962 and 1985 the effects were stronger in cities with pollution mainly from traffic than in areas with pollution from industrial sources. In total, between 1962 and 1987 two major and several smaller smog episodes occurred in Central Europe. Patients with cardiovascular diseases were more severely affected than patients with respiratory diseases. Health effects were more strongly correlated with TSP than with SO2. PMID:15729831

  10. What can we learn today from the Central European smog episode of 1985 (and earlier episodes)?

    PubMed

    Wichmann, H Erich

    2004-12-01

    In January 1985 an extended smog episode occurred in Central Europe. The Rhine-Ruhr area (Western Germany) was affected for 5 days with maximum concentrations of 0.8 mg/m3 SO2 and 0.6 mg/m3 TSP (24h averages). Health effects were investigated during the smog period and a control period before and after the smog. Daily mortality increased by 8%, hospital admissions (for respiratory and cardiovascular causes, RC) by 15%, outpatients (RC) by 12% and ambulance transports (RC) by 28%. Patients with chronic bronchitis from the Ruhr area cities showed more exacerbations during the episode, and in school children from the Netherlands lung function was reduced. In Augsburg (Southern Germany) the smog episode was less severe (maximum concentrations 0.2 mg/m3 SO2 and 0.1 mg/m3 TSP, 24 h averages). Here--by chance--the prospective MONICA study was ongoing. During the episode a significant increase of plasma viscosity, C-reactive protein and heart rate was observed in the participants. The highest ambient concentrations (maximum 24h average of 3.6 mg/m3 SO2) were measured in Erfurt (Eastern Germany). Surprisingly, no measurable increase of mortality occurred. This was explained by premature deaths during the period before the smog, were the concentrations had already been clearly above 1 mg/m3 SO2. An earlier episode took place in December 1962 in the Rhine-Ruhr area for 5 days with maximum concentrations of 5.0 mg/m3 SO2 and 2.4 mg/m3 TSP (24 h average). Daily mortality on average increased by 19%. In 1962 and 1985 the effects were stronger in cities with pollution mainly from traffic than in areas with pollution from industrial sources. In total, between 1962 and 1987 two major and several smaller smog episodes occurred in Central Europe. Patients with cardiovascular diseases were more severely affected than patients with respiratory diseases. Health effects were more strongly correlated with TSP than with SO2.

  11. Non invasive blood flow measurement in cerebellum detects minimal hepatic encephalopathy earlier than psychometric tests

    PubMed Central

    Felipo, Vicente; Urios, Amparo; Giménez-Garzó, Carla; Cauli, Omar; Andrés-Costa, Maria-Jesús; González, Olga; Serra, Miguel A; Sánchez-González, Javier; Aliaga, Roberto; Giner-Durán, Remedios; Belloch, Vicente; Montoliu, Carmina

    2014-01-01

    CFF. BF in cerebellar hemisphere correlates with plasma cGMP and nitric oxide (NO) metabolites. BF in vermis cerebellar also correlates with NO metabolites and with 3-nitrotyrosine. IL-18 in plasma correlates with BF in thalamus and occipital lobe. CONCLUSION: Non invasive BF determination in cerebellum using ASL may detect MHE earlier than the PHES. Altered NO-cGMP pathway seems to be associated to altered BF in cerebellum. PMID:25206287

  12. Terrestrial environmental changes around the Gulf of Aden over the last 210 kyr deduced from the sediment n-alkane record: Implications for the dispersal of Homo sapiens

    NASA Astrophysics Data System (ADS)

    Isaji, Yuta; Kawahata, Hodaka; Ohkouchi, Naohiko; Murayama, Masafumi; Tamaki, Kensaku

    2015-03-01

    We analyzed long-chain (C25-C36) n-alkanes and pollen grains in sediments from the Gulf of Aden covering the last 212 kyr to reconstruct the surrounding terrestrial environment, a critical region for the dispersal of Homo sapiens. Substantial increases in the flux of n-alkanes during 200-185, 120-95, and 70-50 ka were interpreted to indicate enhanced vegetation biomass in the Arabian Peninsula and the northern part of the Horn of Africa or increase in lithogenic material inputs. Periods of enhanced n-alkane flux occurred during or immediately after pluvial episodes, indicating that the increased precipitation may have induced substantially enhanced vegetation biomass, creating favorable conditions for Homo sapiens. Additionally, vegetation may have increased due to moderate precipitation unrecorded by speleothems or in accordance with the lowering of sea level, indicating that the dispersal might have been possible even after the shift to an arid environment indicated by the speleothems.

  13. An earlier age of breast cancer diagnosis related to more frequent use of antiperspirants/deodorants and underarm shaving.

    PubMed

    McGrath, K G

    2003-12-01

    Breast cancer incidence suggests a lifestyle cause. A lifestyle factor used near the breast is the application of antiperspirants/deodorants accompanied by axillary shaving. A previous study did not support a link with breast cancer. If these habits have a role in breast cancer development, women using antiperspirants/deodorants and shaving their underarms frequently would be expected to have an earlier age of diagnosis than those doing so less often. An earlier age of diagnosis would also be expected in those starting to use deodorants and shaving at an earlier age. This is the first study to investigate the intensity of underarm exposure in a cohort of breast cancer survivors. Four hundred and thirty-seven females diagnosed with breast cancer were surveyed. Once grouped by their frequency of underarm hygiene habits, the mean age of diagnosis was the primary end point. Secondary end points included the overall frequency of these habits, and potential usage group confounding variables were evaluated. All statistical tests were two-sided. Frequency and earlier onset of antiperspirant/deodorant usage with underarm shaving were associated with an earlier age of breast cancer diagnosis. Combined habits are likely for this earlier age of diagnosis. In conclusion, underarm shaving with antiperspirant/deodorant use may play a role in breast cancer. It is not clear which of these components are involved. Reviewed literature insinuates absorption of aluminium salts facilitated by dermal barrier disruption. Case-controlled investigations are needed before alternative underarm hygiene habits are suggested. PMID:14639125

  14. An earlier age of breast cancer diagnosis related to more frequent use of antiperspirants/deodorants and underarm shaving.

    PubMed

    McGrath, K G

    2003-12-01

    Breast cancer incidence suggests a lifestyle cause. A lifestyle factor used near the breast is the application of antiperspirants/deodorants accompanied by axillary shaving. A previous study did not support a link with breast cancer. If these habits have a role in breast cancer development, women using antiperspirants/deodorants and shaving their underarms frequently would be expected to have an earlier age of diagnosis than those doing so less often. An earlier age of diagnosis would also be expected in those starting to use deodorants and shaving at an earlier age. This is the first study to investigate the intensity of underarm exposure in a cohort of breast cancer survivors. Four hundred and thirty-seven females diagnosed with breast cancer were surveyed. Once grouped by their frequency of underarm hygiene habits, the mean age of diagnosis was the primary end point. Secondary end points included the overall frequency of these habits, and potential usage group confounding variables were evaluated. All statistical tests were two-sided. Frequency and earlier onset of antiperspirant/deodorant usage with underarm shaving were associated with an earlier age of breast cancer diagnosis. Combined habits are likely for this earlier age of diagnosis. In conclusion, underarm shaving with antiperspirant/deodorant use may play a role in breast cancer. It is not clear which of these components are involved. Reviewed literature insinuates absorption of aluminium salts facilitated by dermal barrier disruption. Case-controlled investigations are needed before alternative underarm hygiene habits are suggested.

  15. A stacked record of relative geomagnetic paleointensity for the past 270 kyr from the western continental rise of the Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Macrì, Patrizia; Sagnotti, Leonardo; Lucchi, Renata Giulia; Rebesco, Michele

    2006-11-01

    Paleomagnetic and rock magnetic investigations were carried out on four gravity cores recovered from the western continental rise of the Antarctic Peninsula during the SEDANO II cruise of RV OGS-Explora. The studied cores, each about 6.5 m-long, were collected at a depth of 3700-4100 m below the sea level, on the distal gentle side of sediment Drift 7, and consist of very fine-grained sediments spanning through various glacial-interglacial cycles. Detailed analysis of the paleomagnetic and rock magnetic data allowed to reconstruct relative paleointensity (RPI) records (NRM20 mT/ARM20 mT) for each core. We established a refined age model for the studied sequences by correlating individual SEDANO RPI curves to the global RPI stack SINT-800 [Y. Guyodo, J.-P. Valet, Global changes in intensity of the Earth's magnetic field during the past 800 kyr, Nature 399 (1999) 249-252]. The individual normalized SEDANO RPI records are in mutual close agreement; they were thus merged in a RPI stacking curve spanning the last 270 kyr and showing a low standard deviation. This study also points out that RPI records may provide a viable tool to date otherwise difficult-to-date sedimentary sequences, such as those deposited along peri-Antarctic margins. The new RPI chronology indicates that the sampled sedimentary sequence is younger than previously thought and allows a new high-resolution correlation to oxygen isotope stages. Furthermore, we recognized variations in the rock magnetic parameters that appear to be climatically-driven, with changes in the relative proportion of two magnetic mineral populations with distinct coercivities. Rock magnetic and lithological trends observed in the SEDANO cores indicate that during the climatic cycles of the Late Pleistocene this sector of the peri-Antarctic margin was subjected to subtle, yet identifiable, environmental changes, confirming a relatively higher instability of the West Antarctic ice sheet with respect to the East Antarctic

  16. Revision and Validation of the Revised Teacher Beliefs Survey.

    ERIC Educational Resources Information Center

    Benjamin, Jane

    This study revised the Teacher Beliefs Survey (S. Wooley and A. Wooley, 1999; TBS), an instrument to assess teachers beliefs related to constructivist and behaviorist theories of learning, and then studied the validity of the revised TBS. Drawing on a literature review, researchers added items for the existing constructs of the TBS and added a new…

  17. Persistent Intermediate Water Warming during Cold Stadials in the SE Nordic Seas during the Last 65 Kyr

    NASA Astrophysics Data System (ADS)

    Rasmussen, T. L.; Ezat, M.; Groeneveld, J.

    2014-12-01

    In the Nordic seas, conversion of inflowing warm Atlantic surface water to deep cold water through convection is closely linked with climate. During the last glacial period climate underwent rapid millennial-scale variability known as Dansgaard-Oeschger (DO) events, consisting of warm interstadials and cold stadials. Here we present the first benthic foraminiferal Mg/Ca-d18O record from the Nordic seas in order to reconstruct the ocean circulation on DO timescales. The record confirms that modern-like convection took place in the Nordic seas during interstadials with cold bottom water temperatures (BWT) close to modern temperatures. The results show gradual and pronounced BWT increases by 2-5 °C during stadials indicating a stop or near-stop in convection. The BWT peaks are followed by an abrupt drop in temperature at the onset of interstadials indicating the abrupt start of convection and renewed generation of cold deep water. The rise in BWT during stadials confirms earlier interpretations of subsurface inflow of warm Atlantic water below a halocline reaching >1.2 km water depth. The results suggest that warm Atlantic Water never ceased to flow into the Nordic seas during the glacial period with inflow at the surface during the Holocene and warm interstadials switching to subsurface and intermediate inflow during cold stadials. Our results suggest that it is the vertical shifts in the position of the warm Atlantic Water that cause the abrupt surface warmings.

  18. Multimodal Revision Techniques in Webtexts

    ERIC Educational Resources Information Center

    Ball, Cheryl E.

    2014-01-01

    This article examines how an online scholarly journal, "Kairos: Rhetoric, Technology, Pedagogy," mentors authors to revise their webtexts (interactive, digital media scholarship) for publication. Using an editorial pedagogy in which multimodal and rhetorical genre theories are merged with revision techniques found in process-based…

  19. Gendered Performances during Peer Revision

    ERIC Educational Resources Information Center

    Styslinger, Mary E.

    2008-01-01

    This study explored the ways gender is accomplished in varied social contexts during the peer revision process in a secondary English classroom. Using a post-structural feminist theoretical framework, an analysis of classroom discourse provided a basis for understanding the performance of gender during peer revision, the effects of gender…

  20. Surgical Scar Revision: An Overview

    PubMed Central

    Garg, Shilpa; Dahiya, Naveen; Gupta, Somesh

    2014-01-01

    Scar formation is an inevitable consequence of wound healing from either a traumatic or a surgical intervention. The aesthetic appearance of a scar is the most important criteria to judge the surgical outcome. An understanding of the anatomy and wound healing along with experience, meticulous planning and technique can reduce complications and improve the surgical outcome. Scar revision does not erase a scar but helps to make it less noticeable and more acceptable. Both surgical and non-surgical techniques, used either alone or in combination can be used for revising a scar. In planning a scar revision surgeon should decide on when to act and the type of technique to use for scar revision to get an aesthetically pleasing outcome. This review article provides overview of methods applied for facial scar revision. This predominantly covers surgical methods. PMID:24761092

  1. Natural selection for earlier male arrival to breeding grounds through direct and indirect effects in a migratory songbird.

    PubMed

    Velmala, William; Helle, Samuli; Ahola, Markus P; Klaassen, Marcel; Lehikoinen, Esa; Rainio, Kalle; Sirkiä, Päivi M; Laaksonen, Toni

    2015-03-01

    For migratory birds, the earlier arrival of males to breeding grounds is often expected to have fitness benefits. However, the selection differential on male arrival time has rarely been decomposed into the direct effect of male arrival and potential indirect effects through female traits. We measured the directional selection differential on male arrival time in the pied flycatcher (Ficedula hypoleuca) using data from 6 years and annual number of fledglings as the fitness proxy. Using structural equation modeling, we were able to take into account the temporal structure of the breeding cycle and the hierarchy between the examined traits. We found directional selection differentials for earlier male arrival date and earlier female laying date, as well as strong selection differential for larger clutch size. These selection differentials were due to direct selection only as indirect selection for these traits was nonsignificant. When decomposing the direct selection for earlier male arrival into direct and indirect effects, we discovered that it was almost exclusively due to the direct effect of male arrival date on fitness and not due to its indirect effects via female traits. In other words, we showed for the first time that there is a direct effect of male arrival date on fitness while accounting for those effects that are mediated by effects of the social partner. Our study thus indicates that natural selection directly favored earlier male arrival in this flycatcher population. PMID:25859326

  2. Natural selection for earlier male arrival to breeding grounds through direct and indirect effects in a migratory songbird

    PubMed Central

    Velmala, William; Helle, Samuli; Ahola, Markus P; Klaassen, Marcel; Lehikoinen, Esa; Rainio, Kalle; Sirkiä, Päivi M; Laaksonen, Toni

    2015-01-01

    For migratory birds, the earlier arrival of males to breeding grounds is often expected to have fitness benefits. However, the selection differential on male arrival time has rarely been decomposed into the direct effect of male arrival and potential indirect effects through female traits. We measured the directional selection differential on male arrival time in the pied flycatcher (Ficedula hypoleuca) using data from 6 years and annual number of fledglings as the fitness proxy. Using structural equation modeling, we were able to take into account the temporal structure of the breeding cycle and the hierarchy between the examined traits. We found directional selection differentials for earlier male arrival date and earlier female laying date, as well as strong selection differential for larger clutch size. These selection differentials were due to direct selection only as indirect selection for these traits was nonsignificant. When decomposing the direct selection for earlier male arrival into direct and indirect effects, we discovered that it was almost exclusively due to the direct effect of male arrival date on fitness and not due to its indirect effects via female traits. In other words, we showed for the first time that there is a direct effect of male arrival date on fitness while accounting for those effects that are mediated by effects of the social partner. Our study thus indicates that natural selection directly favored earlier male arrival in this flycatcher population. PMID:25859326

  3. Recent Revisions to PVWATTS

    SciTech Connect

    Marion, B.; Anderberg, M.; Gray-Hann, P.

    2005-11-01

    PVWATTS is an Internet-accessible software program that allows the user to easily calculate the energy production and cost savings for grid-connected photovoltaic (PV) systems located throughout the United States. To ensure that PVWATTS continues to meet its users' needs, an online survey form was provided to users to identify areas for improvement. The results of the survey were used to prioritize improvements to PVWATTS in FY2005. PVWATTS was revised by changing the PV system specification input for system size from an AC power rating to a nameplate DC power rating; adding an input for an overall DC to AC derate factor; updating the residential electric rates; adding monthly and yearly solar radiation values for the PV array; and simplifying the user interface for Version 2.

  4. New Archaeointensity Result from Middle-Eastern China and Its Constraints on the Variation of the Geomagnetic Field during the last 6 kyr

    NASA Astrophysics Data System (ADS)

    Cai, S.; Jin, G.; Deng, C.; Tauxe, L.; Qin, H.; Pan, Y.; Zhu, R.

    2015-12-01

    Archaeomagnetic study is an effective way to understand the variation of the geomagnetic field over periods of hundreds to thousands of years. We have carried out archaeointensity studies on archaeological artifacts, including pottery fragments, bricks and baked clay, collected from several sites covering the middle to eastern part of China spanning the past ~6 kyr. We designed detailed rock magnetic and archaeointensity experiments in this study. Rock magnetic results indicate that the main magnetic carriers of these samples are stable magnetite or titanomagnetite with mainly fine particles of SD and SP. About 40% of the specimens in the paleointensity experiment pass the strict selection criteria and are considered to record robust intensity values. The virtual axial dipole moments (VADMs) of our sites range from ~2.5×1022 to ~15.8×1022 Am2. We record three low intensity values with VADMs of less than 3×1022 Am2, two of them comparable to the one reported by Cai et al. (2015) at ~3000 BCE while the other one comparable to those reported by Cai et al. (2014) at ~2200 BCE, which supply further evidence for the existence of 'DIPs' (decreases in paleoinetnsity) in China during the period of ~3000-2000 BCE. A high intensity value of ~16×1022 Am2 is recorded by our new data at ~1300 BCE, which may represent a new spike at this time period. The low and high values recorded by our new data update the six-fold variation between ~2200 BCE and ~1300 BCE discussed in Cai et al. (2014) to eight-fold, which may indicate a stronger geodynamic process during this period. Our new data are generally in good agreement with the published data in China, Japan and Korea at similar time periods, except the extreme low and high values discussed above, which will improve the Eastern Asian model greatly. The new data together with the published data suggest severe fluctuation of the geomagnetic field in Eastern Asia during the last 6 kyr. Vast quantities of reliable data are needed to

  5. Changes in seasonality of organic matter supply to the sea floor in the Eastern Equatorial Pacific over the last 260 kyr based on benthic foraminiferal assemblages

    NASA Astrophysics Data System (ADS)

    Ovsepyan, Ekaterina; Ivanova, Elena; Vidal, Laurence

    2015-04-01

    At present, short- and long-term variations of sea-surface biological productivity in the Eastern Equatorial Pacific have been extensively studied in order to evaluate changes in efficiency of biological carbon dioxide pump in the past. Benthic foraminiferal assemblages are investigated from the IMAGES giant Core MD02-2529 (8°12.5' N, 84° 07.5'W, w.d. 1619 m) off Costa Rica recovered the last 262 kyr according to oxygen isotope stratigraphy confirmed by 15 AMS14C dates in the upper part of the core. A predominance of high productivity species (e.g. hispid Uvigerina, U. peregrina, M. barleeanus, B. mexicana, C. carinata, T. delicata, C. wuellerstorfi, P. bulloides, Chilostomella spp., Globobulimina spp.) in benthic foraminiferal assemblages indicates intensive organic matter supply to the sea floor throughout the interval studied. CABFAC factor analysis applied for the species percentages matrix reveals that changes in taxonomic composition are described by three factors. Factor 1 is loaded mainly to U. hispida and in a less degree to U. peregrina. According to the modern ecological notion (e.g. Loubere, Fariduddin, 1999), U. hispida is associated with high and fairly constant organic matter flux to the seabed. Hence, high values of factor 1 reflect high productivity and low seasonality conditions. Factor 2 is loaded positively to U. peregrina and negatively to U. hispida. U. peregrina prefers slightly degraded organic matter, whereas U. hispida is abundant within the regions where organic matter is fresh and dominated by diatoms. Thus, we suppose that maxima of factor 2 mirror high productivity conditions with non-regular flux of organic matter to the sea floor with several events of phytoplankton blooms over the year (moderate seasonality). We believe that fresh organic matter derived from the photic layer underwent bacterial decomposition between multiple flux pulses and thereby contributed to thrift U. peregrina assemblages. Factor 3 is loaded positively to M

  6. Oxygen isotopes of Pacific seawater, 0-40 kyr, based on d18O and Mg/Ca of benthic and planktic foraminifera: relation to deglacial sealevel rise.

    NASA Astrophysics Data System (ADS)

    Mix, A. C.; Klinkhammer, G. P.

    2007-12-01

    Combining high resolution (~200 year sample resolution) oxygen and carbon isotope measurements and Mg/Ca analyses in planktic (G. ruber and N. dutertrei) and benthic foraminifera (Uvigerina sp.; use of infaunal benthics minimizes likely CO3= effects) from the mid-depth eastern Pacific provides for detailed estimates of changing d18O of seawater over the past 40 kyr at ODP Site 1242. The key to this analysis is improved precision of the Mg/Ca analyses based on a new generation of high precision flow-through time-resolved analysis (FT-TRA) (e.g., average internal precision for Mg/Ca is now +/-0.005 benthic, and +/-0.015 planktic). This method is relatively insensitive to mild dissolution of heterogeneous shells, and thus requires no corrections for preservation. The change in seawater d18O (at 1364 m depth) between the Holocene and Last Glacial Maximum is 1.2 +/- 0.04 permil when averaged over the stages, consistent with pore-water diffusion estimates; however, millennial scale events (which the pore-water data cannot detect) bring the total range up to about 1.6 permil. Are such short-term events related to sealevel change, or do they reflect changing watermasses? Measurements of d13C data (C. wuellerstorfi), sensitive to modern subsurface watermass gradients, are not highly correlated to short- term changes in d18Oseawater suggesting a transient response to ice volume changes. Glacial weakening of AAIW (salty, high d18O, high d13C) relative to north Pacific watermasses (fresher, lower d18O, low d13C) suggest that the benthic d18Oseawater may underestimate total local changes related to ice volume (with a caveat regarding proper scaling of benthic Mg/Ca to temperature). Benthic d18Oseawater falls through the deglaciation in steps, starting at 18 cal ka, with maximum rates of change at 14-15 ka, and with secondary rapid steps at 16-17 ka and 10-11 kar. Planktic foraminifera yield smaller glacial-interglacial d18Oseawater values, with Holocene-to-LGM stage- average

  7. Hydrological and thermal changes along the last 2.7 kyr in the central-western Mediterranean based on a multi-archive approach: speleothem and marine sediments

    NASA Astrophysics Data System (ADS)

    Cisneros, Mercè; Cacho, Isabel; Fornós, Joan J.; Moreno, Ana; Stoll, Heather; Edwards, Larry; Cheng, Hai; Frigola, Jaime

    2016-04-01

    Climatic conditions over the last 2.7 kyr are reconstructed in base to six speleothems from a cave in Mallorca and a group of sediment cores from the Menorca Rise. Speleothem records provide a solid chronology in base to high resolution U/Th dating. Both δ 13C and particularly δ 18O records show pronounced oscillations related to pre-roman times as the Dark Middle Ages, the Medieval Climate Anomaly and the Little Ice Age. The geochemical proxies from the six studied speleothems have been stacked in a unique record, which provides decadal-multidecadal resolution. In parallel, Sea Surface Temperature (SST) conditions have been reconstructed in base to Globigerina bulloides-Mg/Ca ratios from a group of multicore records, and they have been combined with δ18O data to reconstruct changes in the evaporation-precipitation ratio of the basin. These records have also been stacked in a single anomaly curve after the accurate construction of robust multi-proxy chronologies (Cisneros et al., under evaluation). The comparison of the marine and speleothem records reveal the occurrence of synchronous changes in both SST and humidity conditions over land along the last 2.7 kyr, although the relationship of these two climatic variables changed along the different climatic events. These results support that the driest conditions occurred during part of the Roma Classic Period and also during the Medieval Climate Anomaly when climate conditions were mostly warm, but also during the second part of the Little Ice Age when cold conditions dominated. This combined land-sea proxy approach offers a powerful tool to reconstruct past climate variability with highly precise chronologies. REFERENCES: M. Cisneros, I. Cacho, J. Frigola, M. Canals, P. Masqué, B. Martrat, F. Lirer, and G. Margaritelli. Sea surface temperature variability in the central-western Mediterranean Sea during the last 2700 years: a multi-proxy and multi-record approach. Submitted on 28 Sep 2015 for open discussion on

  8. Angiopoietin-Like-4, a Potential Target of Tacrolimus, Predicts Earlier Podocyte Injury in Minimal Change Disease.

    PubMed

    Li, Jian-Si; Chen, Xiao; Peng, Lei; Wei, Shi-Yao; Zhao, Shi-Lei; Diao, Tian-Tian; He, Yi-Xin; Liu, Fang; Wei, Qiu-Ju; Zhang, Qing-Fang; Li, Bing

    2015-01-01

    Podocyte injury plays central roles in proteinuria and kidney dysfunction, therefore, identifying specific biomarker to evaluate earlier podocyte injury is highly desirable. Podocyte-secreted angiopoietin-like-4 (Angptl4) mediates proteinuria in different types of podocytopathy. In the present study, we established an experimental minimal change disease (MCD) rat model, induced by adriamycin (ADR) and resulted in definite podocyte injury, to identify the dynamic changes in Angptl4 expression. We also investigated the direct effects of tacrolimus on Angptl4 and podocyte repair. We determined that the glomerular Angptl4 expression was rapidly upregulated and reached a peak earlier than desmin, an injured podocyte marker, in the ADR rats. Furthermore, this upregulation occurred prior to heavy proteinuria and was accompanied by increased urinary Angptl4. We observed that the Angptl4 upregulation occurred only when podocyte was mainly damaged since we didn't observe little Angptl4 upregulation in MsPGN patients. In addition, we observed the glomerular Angptl4 mainly located in injured podocytes rather than normal podocytes. Moreover, we found that tacrolimus treatment significantly promoted podocyte repair and reduced glomerular and urinary Angptl4 expression at an earlier stage with a significant serum Angptl4 upregulation. And similar results were confirmed in MCD patients. In conclusion, this study represents the first investigation to demonstrate that Angptl4 can predict podocyte injury at earlier stages in MCD and the identification of earlier podocyte injury biomarkers could facilitate the prompt diagnosis and treatment of patients with podocytopathy, as well as determination of the prognosis and treatment efficacy in these diseases.

  9. Spatial and Temporal Variation in Primary Productivity (NDVI) of Coastal Alaskan Tundra: Decreased Vegetation Growth Following Earlier Snowmelt

    NASA Technical Reports Server (NTRS)

    Gamon, John A.; Huemmrich, K. Fred; Stone, Robert S.; Tweedie, Craig E.

    2015-01-01

    In the Arctic, earlier snowmelt and longer growing seasons due to warming have been hypothesized to increase vegetation productivity. Using the Normalized Difference Vegetation Index (NDVI) from both field and satellite measurements as an indicator of vegetation phenology and productivity, we monitored spatial and temporal patterns of vegetation growth for a coastal wet sedge tundra site near Barrow, Alaska over three growing seasons (2000-2002). Contrary to expectation, earlier snowmelt did not lead to increased productivity. Instead, productivity was associated primarily with precipitation and soil moisture, and secondarily with growing degree days, which, during this period, led to reduced growth in years with earlier snowmelt. Additional moisture effects on productivity and species distribution, operating over a longer time scale, were evident in spatial NDVI patterns associated with microtopography. Lower, wetter regions dominated by graminoids were more productive than higher, drier locations having a higher percentage of lichens and mosses, despite the earlier snowmelt at the more elevated sites. These results call into question the oft-stated hypothesis that earlier arctic growing seasons will lead to greater vegetation productivity. Rather, they agree with an emerging body of evidence from recent field studies indicating that early-season, local environmental conditions, notably moisture and temperature, are primary factors determining arctic vegetation productivity. For this coastal arctic site, early growing season conditions are strongly influenced by microtopography, hydrology, and regional sea ice dynamics, and may not be easily predicted from snowmelt date or seasonal average air temperatures alone. Our comparison of field to satellite NDVI also highlights the value of in-situ monitoring of actual vegetation responses using field optical sampling to obtain detailed information on surface conditions not possible from satellite observations alone.

  10. Annotation and Classification of Argumentative Writing Revisions

    ERIC Educational Resources Information Center

    Zhang, Fan; Litman, Diane

    2015-01-01

    This paper explores the annotation and classification of students' revision behaviors in argumentative writing. A sentence-level revision schema is proposed to capture why and how students make revisions. Based on the proposed schema, a small corpus of student essays and revisions was annotated. Studies show that manual annotation is reliable with…

  11. OMB revises overhead rules

    NASA Astrophysics Data System (ADS)

    Katzoff, Judith A.

    After pressure from university administrators, the Office of Management and Budget (OMB) has issued a new plan for saving money on research overhead costs, in place of a controversial proposal that was originally published in February 1986 (Eos, May 20, 1986, p. 481). The agency made the new plan more palatable to administrators and faculty by choosing to cap the rate of reimbursement for the activity that researchers say they find among the most difficult to document: the time they spend on administration of federally sponsored grants and contracts. An amendment to a bill signed by President Ronald Reagan on July 2 might force OMB to make additional concessions to colleges and universities.How much money the federal government would save under this policy is a matter of dispute. The agency's revisions to OMB Circular A-21, “Cost Principles for Educational Institutions,” call for fixing the reimbursement rate at 3% of modified total direct costs for departmental administration work done by “department heads, directors of divisions faculty, and professional staff.” The 3% figure represents about half of the current national average rate of reimbursement for these costs and would lead to federal government savings of $100 million a year, according to OMB.

  12. Linkages between rapid climate variability and deep-sea benthic foraminifera in the deep Subantarctic South Atlantic during the last 95 kyr

    NASA Astrophysics Data System (ADS)

    Diz, Paula; Barker, Stephen

    2015-06-01

    We present a high-resolution record of benthic foraminifera fauna from a sediment core retrieved from the South Cape Basin (Subantarctic South Atlantic) spanning the last glacial cycle (95 kyr). Information provided by benthic foraminiferal assemblages together with paleoclimate proxies from the same core allow us to interpret changes in the style of primary production (episodic versus sustained) in relation to abrupt climate oscillations. Our results indicate that fluctuations in the abundance of the phytodetritus-related species, Epistominella exigua, are concomitant with millennial-scale high-latitude climate perturbations. Episodic phytoplankton blooms increased during a negative mode of the bipolar seesaw, irrespective of the magnitude of the perturbation (i.e., Heinrich stadial versus non-Heinrich stadial events). We provide a hypothesis linking the frequency and intensity of these events to atmospheric perturbations, interhemispheric climate variability, and millennial-scale changes in atmospheric CO2. A notable exception to the overall pattern is the generally high abundance of E. exigua across the globally synchronous onset of glacial marine oxygen isotope stage (MIS) 4, a period generally characterized by increased dustiness and low-quality organic carbon as inferred by the percentage of the nonphytodetritus species. This highlights the special characteristics governing the onset of MIS 4 in the Subantarctic.

  13. A high-resolution mid-Pleistocene temperature record from Arctic Lake El'gygytgyn: a 50 kyr super interglacial from MIS 33 to MIS 31?

    NASA Astrophysics Data System (ADS)

    de Wet, Gregory A.; Castañeda, Isla S.; DeConto, Robert M.; Brigham-Grette, Julie

    2016-02-01

    Previous periods of extreme warmth in Earth's history are of great interest in light of current and predicted anthropogenic warming. Numerous so called "super interglacial" intervals, with summer temperatures significantly warmer than today, have been identified in the 3.6 million year (Ma) sediment record from Lake El'gygytgyn, northeast Russia. To date, however, a high-resolution paleotemperature reconstruction from any of these super interglacials is lacking. Here we present a paleotemperature reconstruction based on branched glycerol dialkyl glycerol tetraethers (brGDGTs) from Marine Isotope Stages (MIS) 35 to MIS 29, including super interglacial MIS 31. To investigate this period in detail, samples were analyzed with an unprecedented average sample resolution of 500 yrs from MIS 33 to MIS 30. Our results suggest the entire period currently defined as MIS 33-31 (∼1114-1062 kyr BP) was characterized by generally warm and highly variable conditions at the lake, at times out of phase with Northern Hemisphere summer insolation, and that cold "glacial" conditions during MIS 32 lasted only a few thousand years. Close similarities are seen with coeval records from high southern latitudes, supporting the suggestion that the interval from MIS 33 to MIS 31 was an exceptionally long interglacial (Teitler et al., 2015). Based on brGDGT temperatures from Lake El'gygytgyn (this study and unpublished results), warming in the western Arctic during MIS 31 was matched only by MIS 11 during the Pleistocene.

  14. Radiometric dating of the Earlier Stone Age sequence in excavation I at Wonderwerk Cave, South Africa: preliminary results.

    PubMed

    Chazan, Michael; Ron, Hagai; Matmon, Ari; Porat, Naomi; Goldberg, Paul; Yates, Royden; Avery, Margaret; Sumner, Alexandra; Horwitz, Liora Kolska

    2008-07-01

    We present here the results of 44 paleomagnetic measurements, and single cosmogenic burial and optically stimulated luminescence ages for the Earlier Stone Age deposits from Wonderwerk Cave, Northern Cape, South Africa. The resulting paleomagnetic sequence: N>R>N>R>N constrains the Earlier Stone Age strata in this part of the site to between approximately 0.78-1.96 Ma. A single cosmogenic date of approximately 2.0 Ma from the base of the section offers some corroboration for the paleomagnetic sequence. Preliminary results indicate that the small lithic assemblage from the basal stratum may contain an Oldowan facies. This is overlain by several strata containing Acheulean industries. The preliminary radiometric dates reported here place the onset of the Acheulean at this site to approximately 1.6 Ma, which is roughly contemporaneous with that of East Africa.

  15. The Earlier the Better? Taking the AP® in 10th Grade. Research Report No. 2012-10

    ERIC Educational Resources Information Center

    Rodriguez, Awilda; McKillip, Mary E. M.; Niu, Sunny X.

    2013-01-01

    In this report, the authors examine the impact of scoring a 1 or 2 on an AP® Exam in 10th grade on later AP Exam participation and performance. As access to AP courses increases within and across schools, a growing number of students are taking AP courses and exams in the earlier grades of high school. Using a matched sample of AP and no-AP…

  16. Return of hunger following a relatively high carbohydrate breakfast is associated with earlier recorded glucose peak and nadir.

    PubMed

    Chandler-Laney, Paula C; Morrison, Shannon A; Goree, Laura Lee T; Ellis, Amy C; Casazza, Krista; Desmond, Renee; Gower, Barbara A

    2014-09-01

    The aim of this study is to test the hypothesis that a breakfast meal with high carbohydrate/low fat results in an earlier increase in postprandial glucose and insulin, a greater decrease below baseline in postprandial glucose, and an earlier return of appetite, compared with a low carbohydrate/high fat meal. Overweight but otherwise healthy adults (n = 64) were maintained on one of two eucaloric diets: high carbohydrate/low fat (HC/LF; 55:27:18% kcals from carbohydrate:fat:protein) versus low carbohydrate/high fat (LC/HF; 43:39:18% kcals from carbohydrate:fat:protein). After 4 weeks of acclimation to the diets, participants underwent a meal test during which circulating glucose and insulin and self-reported hunger and fullness, were measured before and after consumption of breakfast from their assigned diets. The LC/HF meal resulted in a later time at the highest and lowest recorded glucose, higher glucose concentrations at 3 and 4 hours post meal, and lower insulin incremental area under the curve. Participants consuming the LC/HF meal reported lower appetite 3 and 4 hours following the meal, a response that was associated with the timing of the highest and lowest recorded glucose. Modest increases in meal carbohydrate content at the expense of fat content may facilitate weight gain over the long-term by contributing to an earlier rise and fall of postprandial glucose concentrations and an earlier return of appetite.

  17. Carl Friedrich Gauss - General Theory of Terrestrial Magnetism - a revised translation of the German text

    NASA Astrophysics Data System (ADS)

    Glassmeier, K.-H.; Tsurutani, B. T.

    2014-02-01

    This is a translation of the Allgemeine Theorie des Erdmagnetismus published by Carl Friedrich Gauss in 1839 in the Resultate aus den Beobachtungen des Magnetischen Vereins im Jahre 1838. The current translation is based on an earlier translation by Elizabeth Juliana Sabine published in 1841. This earlier translation has been revised, corrected, and extended. Numerous biographical comments on the scientists named in the original text have been added as well as further information on the observational material used by Carl Friedrich Gauss. An attempt is made to provide a readable text to a wider scientific community, a text laying the foundation of today's understanding of planetary magnetic fields.

  18. Northern ragweed ecotypes flower earlier and longer in response to elevated CO2: what are you sneezing at?

    PubMed

    Stinson, Kristina A; Albertine, Jennifer M; Hancock, Laura M S; Seidler, Tristram G; Rogers, Christine A

    2016-10-01

    Significant changes in plant phenology and flower production are predicted over the next century, but we know relatively little about geographic patterns of this response in many species, even those that potentially impact human wellbeing. We tested for variation in flowering responses of the allergenic plant, Ambrosia artemisiifolia (common ragweed). We grew plants originating from three latitudes in the Northeastern USA at experimental levels of CO2 (400, 600, and 800 µL L(-1)). We hypothesized that northern ecotypes adapted to shorter growing seasons would flower earlier than their southern counterparts, and thus disproportionately allocate carbon gains from CO2 to reproduction. As predicted, latitude of origin and carbon dioxide level significantly influenced the timing and magnitude of flowering. Reproductive onset occurred earlier with increasing latitude, with concurrent increases in the number of flowers produced. Elevated carbon dioxide resulted in earlier reproductive onset in all ecotypes, which was significantly more pronounced in the northern populations. We interpret our findings as evidence for ecotypic variation in ragweed flowering time, as well in responses to CO2. Thus, the ecological and human health implications of common ragweed's response to global change are likely to depend on latitude. We conclude that increased flower production, duration, and possibly pollen output, can be expected in Northeastern United States with rising levels of CO2. The effects are likely, however, to be most significant in northern parts of the region. PMID:27318697

  19. Northern ragweed ecotypes flower earlier and longer in response to elevated CO2: what are you sneezing at?

    PubMed

    Stinson, Kristina A; Albertine, Jennifer M; Hancock, Laura M S; Seidler, Tristram G; Rogers, Christine A

    2016-10-01

    Significant changes in plant phenology and flower production are predicted over the next century, but we know relatively little about geographic patterns of this response in many species, even those that potentially impact human wellbeing. We tested for variation in flowering responses of the allergenic plant, Ambrosia artemisiifolia (common ragweed). We grew plants originating from three latitudes in the Northeastern USA at experimental levels of CO2 (400, 600, and 800 µL L(-1)). We hypothesized that northern ecotypes adapted to shorter growing seasons would flower earlier than their southern counterparts, and thus disproportionately allocate carbon gains from CO2 to reproduction. As predicted, latitude of origin and carbon dioxide level significantly influenced the timing and magnitude of flowering. Reproductive onset occurred earlier with increasing latitude, with concurrent increases in the number of flowers produced. Elevated carbon dioxide resulted in earlier reproductive onset in all ecotypes, which was significantly more pronounced in the northern populations. We interpret our findings as evidence for ecotypic variation in ragweed flowering time, as well in responses to CO2. Thus, the ecological and human health implications of common ragweed's response to global change are likely to depend on latitude. We conclude that increased flower production, duration, and possibly pollen output, can be expected in Northeastern United States with rising levels of CO2. The effects are likely, however, to be most significant in northern parts of the region.

  20. Inevitable end-of-21st-century trends toward earlier surface runoff timing in California's Sierra Nevada Mountains

    NASA Astrophysics Data System (ADS)

    Schwartz, M. A.; Hall, A. D.; Sun, F.; Walton, D.; Berg, N.

    2015-12-01

    Hybrid dynamical-statistical downscaling is used to produce surface runoff timing projections for California's Sierra Nevada, a high-elevation mountain range with significant seasonal snow cover. First, future climate change projections (RCP8.5 forcing scenario, 2081-2100 period) from five CMIP5 global climate models (GCMs) are dynamically downscaled. These projections reveal that future warming leads to a shift toward earlier snowmelt and surface runoff timing throughout the Sierra Nevada region. Relationships between warming and surface runoff timing from the dynamical simulations are used to build a simple statistical model that mimics the dynamical model's projected surface runoff timing changes given GCM input or other statistically-downscaled input. This statistical model can be used to produce surface runoff timing projections for other GCMs, periods, and forcing scenarios to quantify ensemble-mean changes, uncertainty due to intermodel variability and consequences stemming from choice of forcing scenario. For all CMIP5 GCMs and forcing scenarios, significant trends toward earlier surface runoff timing occur at elevations below 2500m. Thus, we conclude that trends toward earlier surface runoff timing by the end-of-the-21st century are inevitable. The changes to surface runoff timing diagnosed in this study have implications for many dimensions of climate change, including impacts on surface hydrology, water resources, and ecosystems.

  1. Parallel programming with PCN. Revision 2

    SciTech Connect

    Foster, I.; Tuecke, S.

    1993-01-01

    PCN is a system for developing and executing parallel programs. It comprises a high-level programming language, tools for developing and debugging programs in this language, and interfaces to Fortran and Cthat allow the reuse of existing code in multilingual parallel programs. Programs developed using PCN are portable across many different workstations, networks, and parallel computers. This document provides all the information required to develop parallel programs with the PCN programming system. It includes both tutorial and reference material. It also presents the basic concepts that underlie PCN, particularly where these are likely to be unfamiliar to the reader, and provides pointers to other documentation on the PCN language, programming techniques, and tools. PCN is in the public domain. The latest version of both the software and this manual can be obtained by anonymous ftp from Argonne National Laboratory in the directory pub/pcn at info.mcs. ani.gov (cf. Appendix A). This version of this document describes PCN version 2.0, a major revision of the PCN programming system. It supersedes earlier versions of this report.

  2. Revision of Primary Series Maps

    USGS Publications Warehouse

    ,

    2000-01-01

    In 1992, the U.S. Geological Survey (USGS) completed a 50-year effort to provide primary series map coverage of the United States. Many of these maps now need to be updated to reflect the construction of new roads and highways and other changes that have taken place over time. The USGS has formulated a graphic revision plan to help keep the primary series maps current. Primary series maps include 1:20,000-scale quadrangles of Puerto Rico, 1:24,000- or 1:25,000-scale quadrangles of the conterminous United States, Hawaii, and U.S. Territories, and 1:63,360-scale quadrangles of Alaska. The revision of primary series maps from new collection sources is accomplished using a variety of processes. The raster revision process combines the scanned content of paper maps with raster updating technologies. The vector revision process involves the automated plotting of updated vector files. Traditional processes use analog stereoplotters and manual scribing instruments on specially coated map separates. The ability to select from or combine these processes increases the efficiency of the National Mapping Division map revision program.

  3. Rayleigh's Scattering Revised

    NASA Astrophysics Data System (ADS)

    Kolomiets, Sergey; Gorelik, Andrey

    Mie’s waves while sounding within coincident volumes. Being sensitive to the size of scatters, Mie’s waves can give us additional information about particle size distribution. But how about using several wavelengths corresponding to Rayleigh’s diffraction on scatters only? Can any effects be detected in such a case and what performance characteristics of the equipment are required to detect them? The deceptive simplicity of the negative answer to the first part of the question posed will disappear if one collects different definitions of Rayleigh's scattering and consider them more closely than usually. Several definitions borrowed from the introductory texts and most popular textbooks and articles can be seen as one of the reasons for the research presented in the report. Hopefully, based on the comparison of them all, anyone could easily conclude that Rayleigh's scattering has been analyzed extensively, but despite this extensive analysis made fundamental ambiguities in introductory texts are not eliminated completely to date. Moreover, there may be found unreasonably many examples on how these ambiguities have already caused an error to be foreseen, published on the one article, amplified in another one, then cited with approval in the third one, before being finally corrected. Everything indicated that in the light of all the lesions learned and based on modern experimental data, it is time to address these issues again. After the discussion of ambiguities of Rayleigh's scattering concepts, the development of the corrections to original ideas looks relatively easy. In particular, there may be distinguished at least three characteristic regions of the revised models application from the point of view of the scattered field statistical averaging. The authors of the report suggest naming them Rayleigh’s region, Einstein’s region and the region with compensations of the scattering intensity. The most important fact is that the limits of applicability of all

  4. Volcanic evolution of an active magmatic rift segment on a 100 Kyr timescale: exposure dating of lavas from the Manda Hararo/Dabbahu segment of the Afar Rift

    NASA Astrophysics Data System (ADS)

    Medynski, S.; Williams, A.; Pik, R.; Burnard, P.; Vye, C.; France, L.; Ayalew, D.; Yirgu, G.

    2012-12-01

    In the Afar depression (Ethiopia), extension is already organised along rift segments which morphologically resemble oceanic rifts. Segmentation here results from interactions between dyke injection and volcanism, as observed during the well documented 2005 event on the Dabbahu rift segment. During this tectono-volcanic crisis, a megadyke was injected, followed by 12 subsequent dike intrusions, sometimes associated with fissure flow eruptions. Despite the accurate surveying of the magmatic and tectonic interplay during this event via remote sensing techniques, there is a lack of data on timescales of 1 to 100 kyr, the period over which the main morphology of a rift is acquired. The Dabbahu rift segment represents an ideal natural laboratory to study the evolution of rift morphology as a response to volcanic and tectonic influences. It is possible to constrain the timing of fault growth relative to the infilling of the rift axial depression by lava flows, and to assess the influence of the different magma bodies involved in lava production along the rift-segment. We use cosmogenic nuclides (3He) to determine the ages of young (<100 kyr) lava flows and to date the initiation and movement of fault scarps which cut the lavas. Combined with major & trace element compositions, field mapping and digital cartography (Landsat, ASTER and SPOT imagery), the rift geomorphology can be linked to the magmatic and tectonic history defined by surface exposure dating. The results show that over the last 100 ka the Northern part of the Dabbahu segment was supplied by two different magma reservoirs which can be identified based on their distinctive chemistries. The main reservoir is located beneath Dabbahu volcano, and has been supplied with magma for at least 72 ka. This magmatic centre supplies magma to most of the northern third of the rift segment. The second reservoir is located further south, on the axis, close to the current mid-segment magma chamber, which was responsible for

  5. Sediment transport process and East Asian monsoon evolution during the last 410 kyr in the northern South China Sea: a multi-proxy approach

    NASA Astrophysics Data System (ADS)

    Chen, Quan; Liu, Zhifei; Kissel, Catherine

    2015-04-01

    Terrigenous detrital materials buried at sea is a book documenting their whole life, including the continental environment where they originated from and the transport process they experienced. In order to reconstruct the East Asian monsoon evolution in late Quaternary, we need to read this book correctly. The key problem is to well understand the proxies and pick the right ones, because most of them are affected by several factors. In this study, clay and magnetic mineralogical measurements and geochemical XRF analyses were conducted on Core MD12-3432 taken from the northern South China Sea at 2125 m water depth during the CIRCEA cruise organized within Franco-Chinese LIA-MONOCL framework on board the R.V. Marion Dufresne. The age model is derived from both carbonate and magnetic stratigraphy. The clearly identified Laschamp and Iceland Basin geomagnetic excursions are used as tie points. Coupled earth magnetic field paleointensity and carbonate content record calibrated from XRF core scanned calcium intensity, we established a robust age model, indicating that Core MD12-3432 covers the last 410 kyr with an average sedimentation rate of 12.4 cm/kyr. The calibrated XRF-scan data provide high-resolution Ti/Ca, Al/Si and K/Al ratios. Ti/Ca and Al/Si ratios vary in phase, indicating strong clastic flux and short transport distances during glacials. Variations in K/Al ratio show an independent pattern, suggesting that temperature-driven chemical weathering is not the main control factor. Special attention needs therefore to be paid to the transport process. For that purpose, anisotropy of magnetic susceptibility was measured on discrete samples at 50 cm intervals. Orientations of the principal anisotropy axes could be reconstructed, using the NRM declination to orient the core in the horizontal plane. The maximum axis is relatively well oriented in the stratigraphic plane of the sedimentary magnetic fabric. A 90° shift is observed at the MIS 5-6 boundary, suggesting a

  6. The revised classification of eukaryotes

    PubMed Central

    Adl, Sina M.; Simpson, Alastair. G.; Lane, Christopher E.; Lukeš, Julius; Bass, David; Bowser, Samuel S.; Brown, Matt; Burki, Fabien; Dunthorn, Micah; Hampl, Vladimir; Heiss, Aaron; Hoppenrath, Mona; Lara, Enrique; leGall, Line; Lynn, Denis H.; McManus, Hilary; Mitchell, Edward A. D.; Mozley-Stanridge, Sharon E.; Parfrey, Laura Wegener; Pawlowski, Jan; Rueckert, Sonja; Shadwick, Lora; Schoch, Conrad; Smirnov, Alexey; Spiegel, Frederick W.

    2012-01-01

    This revision of the classification of eukaryotes, which updates that of Adl et al. (2005), retains an emphasis on the protists and incorporates changes since 2005 that have resolved nodes and branches in phylogenetic trees. Whereas the previous revision was successful in re-introducing name stability to the classification, this revision provides a classification for lineages that were then still unresolved. The supergroups have withstood phylogenetic hypothesis testing with some modifications, but despite some progress, problematic nodes at the base of the eukaryotic tree still remain to be statistically resolved. Looking forward, subsequent transformations to our understanding of the diversity of life will be from the discovery of novel lineages in previously under-sampled areas and from environmental genomic information. PMID:23020233

  7. The revised classification of eukaryotes.

    PubMed

    Adl, Sina M; Simpson, Alastair G B; Lane, Christopher E; Lukeš, Julius; Bass, David; Bowser, Samuel S; Brown, Matthew W; Burki, Fabien; Dunthorn, Micah; Hampl, Vladimir; Heiss, Aaron; Hoppenrath, Mona; Lara, Enrique; Le Gall, Line; Lynn, Denis H; McManus, Hilary; Mitchell, Edward A D; Mozley-Stanridge, Sharon E; Parfrey, Laura W; Pawlowski, Jan; Rueckert, Sonja; Shadwick, Laura; Shadwick, Lora; Schoch, Conrad L; Smirnov, Alexey; Spiegel, Frederick W

    2012-09-01

    This revision of the classification of eukaryotes, which updates that of Adl et al. [J. Eukaryot. Microbiol. 52 (2005) 399], retains an emphasis on the protists and incorporates changes since 2005 that have resolved nodes and branches in phylogenetic trees. Whereas the previous revision was successful in re-introducing name stability to the classification, this revision provides a classification for lineages that were then still unresolved. The supergroups have withstood phylogenetic hypothesis testing with some modifications, but despite some progress, problematic nodes at the base of the eukaryotic tree still remain to be statistically resolved. Looking forward, subsequent transformations to our understanding of the diversity of life will be from the discovery of novel lineages in previously under-sampled areas and from environmental genomic information.

  8. Phytoliths Used to Investigate the Effects of the Indonesian Mount Toba Super-Eruption (~75 kyr) in East Africa: A Subdecadal Record from Lake Malawi

    NASA Astrophysics Data System (ADS)

    Yost, C. L.; Cohen, A. S.

    2014-12-01

    The recent discovery of cryptotephra visually and chemically matched to the Youngest Toba Tuff (YTT, 75.0 ± 0.9 kyr) in Lake Malawi drill core sediments has spurred renewed interest in this period of time in East Africa. The YTT is the most recent and largest of the four Mount Toba eruptions, and is the only super-eruption to have taken place during the Quaternary. The timing of the YTT approximately coincides with a hypothesized human genetic bottleneck. Several climate models have proposed an episode of global cooling following the YTT; however, the magnitude and duration of the cooling is much debated, ranging from just a few degrees of cooling to a state of volcanic winter. Cored sediments from Lake Malawi provide an excellent record of local variability in the lake's watershed that may be linked to specific climatic events. To investigate the possible effects of the YTT in East Africa, we continuously sampled Lake Malawi drill core 2A-10H-2 at 2-4 mm (~6 yr) intervals above and below the first occurrence of the YTT. Poaceae phytoliths were grouped into plant functional types (C3, C4, xerophytic, mesophytic, arboreal, etc.), revealing mostly subtle changes in terrestrial vegetation over the ~400 yr time period examined. Abrupt increases in concentration values for phytoliths derived from riverine Podostemaceae plants appear to signal increased discharge from rivers draining the surrounding uplands. Perhaps most significant is the increasing trend in burned phytoliths and decreasing trend in tree phytoliths post-YTT. Although there appears to be a very weak cooling signal synchronous with the YTT, the most abrupt terrestrial vegetation changes appear to be better correlated with the deposition of a slightly older cryptotephra horizon derived from the local Rungwe Volcanic Province. A potential complication with this record is the existence of a turbidite pre-YTT that encompasses the Rungwe horizon.

  9. A ~600 kyr duration Early Pleistocene record from the West Turkana (Kenya) HSPDP drill site: elemental XRF variability to reconstruct climate change in Turkana Boy's backyard

    NASA Astrophysics Data System (ADS)

    Stockhecke, M.; Beck, C. C.; Brown, E. T.; Cohen, A.; Deino, A. L.; Feibel, C. S.; Sier, M.

    2015-12-01

    . In addition, the XRF record of the changing hydroclimate of the West Turkana Basin from 1.3 to 1.9 kyrs will be explored in relation to regional reconstructions and marine stratigraphies.

  10. Response of diatom and silicoflagellate assemblages in the central Gulf of California to regional climate change during the past 55 kyrs

    USGS Publications Warehouse

    Barron, John A.; Bukry, David; Cheshire, Heather

    2014-01-01

    High-resolution studies of diatoms and silicoflagellates of the past 55 kyrs in cores MD02-2517/2515 from the central Gulf of California (GoC) reveal profound changes in GoC surface waters. Roperia tesselata, a diatom proxy for late winter–early spring upwelling, and Dictyocha stapedia, a subtropical silicoflagellate indicative of GoC sea surface temperatures (SSTs) > 24 °C, are common during the Holocene but rare during Marine Isotope Stage (MIS) 2 and most of MIS 3, a relationship that likely reflects a more northerly position of the North Pacific High (NPH) during the Holocene. In contrast during most of MIS 2 (~ 27–15 ka), the persistent presence of Distephanus speculum, a silicoflagellate associated with SSTs During MIS 3 (~ 55–27 ka), increased dominance of Azpeitia nodulifera (diatom) implies that stratified, tropical waters were present year round, whereas silicoflagellate assemblages suggest that stratified tropical conditions alternated with more productive, upwelling conditions on millennial timescales. Reduced biosiliceous productivity during Heinrich events likely reflected a reduction in both surface water nutrient levels and in the strength of northwest winds due to a weakened and more southerly NPH. Conversely, enhanced biosiliceous productivity during MIS 3 interstadials was probably linked to heightened nutrient levels and a strengthened NPH. Abrupt relative abundance increases of the silicoflagellate, Dictyocha aculeata, approximate the termination of MIS3 Heinrich events and may signal times when nutrient-rich deep waters associated with the resumption of enhanced Atlantic Meridional Overturning Circulation penetrated into the central Gulf.

  11. Decade to centennial resolution hydrogen isotopic record of climate change from southern New England for the past 16 kyr: proxy validation and multi-proxy comparisons

    NASA Astrophysics Data System (ADS)

    Huang, Y.; Gao, L.; Hou, J.; Shuman, B. N.; Oswald, W.; Foster, D.

    2009-12-01

    Open system lakes in New England offer excellent archives of precipitation isotopic ratios that yield quantitative paleoclimate information. We have demonstrated previously from a lake sediment transect that hydrogen isotopic ratios of a middle-chain length fatty acid, behenic acid (BA), faithfully record precipitation isotopic ratios. We hypothesized that mid-chain n-alkyl lipids in these small lakes were primarily derived from aquatic plants that record lake water isotopic ratios. To test this hypothesis, we conducted systematic and extensive sampling of both terrestrial and aquatic plants over the past two years at two typical kettle hole lakes, Blood Pond and Rocky Pond, MA, and used a linear algebra approach to delineate percentage inputs of aquatic and terrestrial plant contributions to mid-chain n-alkyl lipids. Our results demonstrate that >92 % of the mid-chain n-alkyl lipids is derived from submerged and floating aquatic macrophytes. Our new data provide a solid basis for the application of behenic hydrogen isotopic ratios as a paleoclimate proxy from small lakes. We will present a decadal to centennial scale 16 kyr record of BA hydrogen isotopic ratios from Blood Pond, and will discuss the results in light of published pollen and lake level data. Overall, our hydrogen isotopic record is fully consistent with regional climate scenarios, including the distinctive warming at B-A events, abrupt cooling at YD event, and transition from glacial to Holcoene climate conditions. However, our high-solution isotopic data provides important new insights concerning abrupt regional climate variability. We demonstrate that the New England climate is exceptionally senstive to AMOC changes and solar forcing and that many of the abrupt climate fluctuations exert major impacts on terrestrial ecosystems, hydrology and lake levels.

  12. Deep water circulation in the eastern Mediterranean Sea for the last 95 kyr: new insights from stable isotopes and benthic foraminiferal assemblages

    NASA Astrophysics Data System (ADS)

    Cornuault, Marine; Vidal, Laurence; Tachikawa, Kazuyo; Licari, Laetitia; Rouaud, Guillaume; Sonzogni, Corinne; Revel, Marie

    2016-04-01

    The response of the Eastern Mediterranean Sea circulation to climate forcing over the last 95 kyr BP was studied using core MD04-2722 collected at 1780m water depth in the Levantine Sea. Foraminiferal stable isotopes and benthic foraminiferal assemblages were combined to reconstruct deep water ventilation and oxygenation in relation to surface water freshening. Over the last deglaciation, benthic foraminiferal δ13C values and benthic foraminiferal oxygen index decreased while δ18O gradient between benthic and planktonic foraminifera increased. These results testify respectively of slower ventilation, bottom water oxygen depletion and stronger stratification prior to S1 sapropel deposition. Similar conditions were deduced for S3 sapropel. Combination of deglacial sea level rise and fresher North Atlantic surface water contribution were evaluated to be a precondition of S1 formation in the Levantine Sea. Local Nile freshwater supply during the African Humid Period further strengthened the water column stratification. For the last glacial period, three events at around 53, 46 and 37 ka BP were marked by benthic δ13C decrease demonstrating deep water circulation reduction at the core location. Bottom water oxygenation was only slightly lowered. Considering the effect of North Atlantic surface water salinity to the Mediterranean Sea circulation, we propose the 46 and 37 ka BP events as responses to the Heinrich Events 4 and 5 that supplied fresher surface water to the Mediterranean Sea. Since the '53 ka event' is characterized by the appearance of an anoxic benthic foraminiferal species observed for S1 and S3 layers, we tentatively attributed it to the 'missing' sapropel S2. Our results indicate that intense stagnation in the Eastern Mediterranean Sea could occur when both local freshwater supply and fresher North Atlantic surface water contributed. The influence of North Atlantic condition was significant on the eastern Mediterranean circulation under warm and cold

  13. Sea surface temperature variations in the western Mediterranean Sea over the last 20 kyr: A dual-organic proxy (UK'37 and LDI) approach

    NASA Astrophysics Data System (ADS)

    Rodrigo-Gámiz, M.; Martínez-Ruiz, F.; Rampen, S. W.; Schouten, S.; Sinninghe Damsté, J. S.

    2014-02-01

    A high-resolution sea surface temperature (SST) reconstruction of the western Mediterranean was accomplished using two independent, algae-based molecular organic proxies, i.e., the UK'37 index based on long-chain unsaturated ketones and the novel long-chain diol index (LDI) based on the relative abundances of C28 and C30 1,13- and 1,15-diols. Two marine records, from the western and eastern Alboran Sea basin, spanning the last 14 and 20 kyr, respectively, were studied. Results from the surface sediments suggest that the two proxies presently reflect seasons with similar SST or simply annual mean SST. Both proxy records reveal the transition from the Last Glacial Maximum to the Holocene in the eastern Alboran Sea with an SST increase of approximately 7°C for UK'37 and 9°C for LDI. Minimum SSTs (10-12°C) are reached at the end of the Last Glacial Maximum and during the last Heinrich event with a subsequent rapid SST increase in LDI-SST toward the beginning of the Bölling period (20°C), while UK'37-SST remains constantly low (~12°C). The Bölling-Alleröd period is characterized by a rapid increase and subsequent decrease in UK'37-SST, while the LDI-SST decrease continuously. Short-term fluctuations in UK'37-SST are probably related to the availability of nutrients and seasonal changes. The Younger Dryas is recorded as a short cold interval followed by progressively warmer temperatures. During the Holocene, the general lower UK'37-derived temperature values in the eastern Alboran (by approximately 1.5-2°C) suggest a southeastward cold water migration by the western Alboran gyre and divergence in the haptophyte blooming season between both basins.

  14. Varying responses to Indian monsoons during the past 220 kyr recorded in deep-sea sediments in inner and outer regions of the Gulf of Aden

    NASA Astrophysics Data System (ADS)

    Isaji, Yuta; Kawahata, Hodaka; Ohkouchi, Naohiko; Ogawa, Nanako O.; Murayama, Masafumi; Inoue, Kazuki; Tamaki, Kensaku

    2015-11-01

    Although the climate in the Arabian Sea is controlled primarily by the southwest monsoon, the southwest monsoon has little influence in the Gulf of Aden. To examine the different responses to monsoons between the Gulf of Aden and areas outside the gulf, a comprehensive data set of bulk organic and inorganic geochemistry, sea surface temperature, and δ15N of pheopigments was obtained from deep-sea sediment cores recovered from inner and outer regions of the gulf. The results indicated that during the past 220 kyr, the influence of the southwest monsoon was stronger in the outer region of the gulf than in the inner region, which implies that the southwest monsoon trajectory has not changed substantially during that time period. Furthermore, influxes of O2-depleted water from the Southern Ocean and the lateral advection of upwelled seawater also had limited influence in the inner region. In contrast, concentrations of lithogenic materials transported by the southwest monsoon were similar in the two regions. δ15N of pheopigments indicated that during the last glacial maximum, the southwest monsoon was weaker and the northeast monsoon was stronger than at present. A stronger southwest monsoon during interglacials enhanced primary productivity and may have caused anoxic conditions to develop in the Arabian Sea, as indicated by redox proxies in the outer region. Anoxic conditions also formed during MIS 3, but no increase in the primary productivity is indicated; therefore, another mechanism, such as an influx of O2-depleted water from the Southern Ocean, may have been the cause.

  15. Rapid directional changes associated with a 6.5 kyr-long Blake geomagnetic excursion at the Blake-Bahama Outer Ridge

    NASA Astrophysics Data System (ADS)

    Bourne, Mark; Mac Niocaill, Conall; Thomas, Alex L.; Knudsen, Mads Faurschou; Henderson, Gideon M.

    2012-06-01

    Geomagnetic excursions are recognized as intrinsic features of the Earth's magnetic field. High-resolution records of field behaviour, captured in marine sedimentary cores, present an opportunity to determine the temporal and geometric character of the field during geomagnetic excursions and provide constraints on the mechanisms producing field variability. We present here the highest resolution record yet published of the Blake geomagnetic excursion (∼125 ka) measured in three cores from Ocean Drilling Program (ODP) Site 1062 on the Blake-Bahama Outer Ridge. The Blake excursion has a controversial structure and timing but these cores have a sufficiently high sedimentation rate (∼10 cm ka-1) to allow detailed reconstruction of the field behaviour at this site during the excursion. Palaeomagnetic measurements of the cores reveal rapid transitions (<500 yr) between the contemporary stable normal polarity and a completely reversed state of long duration which spans a stratigraphic interval of 0.7 m. We determine the duration of the reversed state during the Blake excursion using oxygen isotope stratigraphy, combined with 230Th excess measurements to assess variations in the sedimentation rates through the sections of interest. This provides an age and duration for the Blake excursion with greater accuracy and with constrained uncertainty. We date the directional excursion as falling between 129 and 122 ka with a duration for the deviation of 6.5±1.3 kyr. The long duration of this interval and the fully reversed field suggest the existence of a pseudo-stable, reversed dipole field component during the excursion and challenge the idea that excursions are always of short duration.

  16. Self-Reported Traumatic Brain Injury and Mild Cognitive Impairment: Increased Risk and Earlier Age of Diagnosis

    PubMed Central

    LoBue, Christian; Denney, David; Hynan, Linda S.; Rossetti, Heidi C.; Lacritz, Laura H.; Hart, John; Womack, Kyle B.; Woon, Fu L.; Cullum, DC. Munro

    2016-01-01

    This study examined whether history of traumatic brain injury (TBI) is associated with increased risk and earlier onset of mild cognitive impairment (MCI). Subjects with MCI (n =3,187) and normal cognition (n=3,244) were obtained from the National Alzheimer's Coordinating Center database. TBI was categorized based on lifetime reported TBI with loss of consciousness (LOC) without chronic deficit. Logistic regression was used to examine TBI history as a predictor of MCI, adjusted for demographics, apolipoprotein E-e4 (Apoe4), a composite vascular risk score, and history of psychiatric factors. ANCOVA was used to examine whether age at MCI diagnosis and estimated age of onset differed between those with (TBI+) and without (TBI-) a history of TBI. TBI history was a significant predictor (p<.01) and associated with increased odds of MCI diagnosis in unadjusted (OR=1.25; 95% CI =1.05 – 1.49) and adjusted models, accounting for age, education, Apoe4, and a composite vascular score (OR=1.32; 95% CI=1.10 – 1.58). This association, however, was largely attenuated (OR=1.14; 95% CI=0.94 – 1.37; p=.18) after adjustment for reported history of depression. MCI was diagnosed a mean of 2.3 years earlier (p<.001) in the TBI+ group, and although TBI+ subjects had an estimated mean of decline 1.7 years earlier, clinician-estimated age of onset failed to differ (p =.13) when sex and psychiatric factors were controlled. This is the first report of a possible role for TBI as a risk factor in MCI, but its association may be related to other factors such as sex and depression and requires further investigation. PMID:26890760

  17. Do emotional support and classroom organization earlier in the year set the stage for higher quality instruction?

    PubMed

    Curby, Timothy W; Rimm-Kaufman, Sara E; Abry, Tashia

    2013-10-01

    Many teachers believe that providing greater emotional and organizational supports in the beginning of the year strengthens their ability to teach effectively as the year progresses. Some interventions, such as the Responsive Classroom (RC) approach, explicitly embed this sequence into professional development efforts. We tested the hypothesis that earlier emotional and organizational supports set the stage for improved instruction later in the year in a sample of third- and fourth-grade teachers enrolled in a randomized controlled trial of the RC approach. Further, we examined the extent to which the model generalized for teachers using varying levels of RC practices as well as whether or not teachers were in the intervention or control groups. Teachers' emotional, organizational, and instructional interactions were observed using the Classroom Assessment Scoring System (Pianta, La Paro, & Hamre, 2008) on five occasions throughout the year. Results indicated a reciprocal relation between emotional and instructional supports. Specifically, higher levels of emotional support earlier in the year predicted higher instructional support later in the year. Also, higher levels of instructional support earlier in the year predicted higher emotional support later in the year. Classroom organization was not found to have longitudinal associations with the other domains across a year. This pattern was robust when controlling for the use of RC practices as well as across intervention and control groups. Further, teachers' use of RC practices predicted higher emotional support and classroom organization throughout the year, suggesting the malleability of this teacher characteristic. Discussion highlights the connection between teachers' emotional and instructional supports and how the use of RC practices improves teachers' emotionally supportive interactions with students.

  18. Failure of aseptic revision total knee arthroplasties

    PubMed Central

    Leta, Tesfaye H; Lygre, Stein Håkon L; Skredderstuen, Arne; Hallan, Geir; Furnes, Ove

    2015-01-01

    Background and purpose In Norway, the proportion of revision knee arthroplasties increased from 6.9% in 1994 to 8.5% in 2011. However, there is limited information on the epidemiology and causes of subsequent failure of revision knee arthroplasty. We therefore studied survival rate and determined the modes of failure of aseptic revision total knee arthroplasties. Method This study was based on 1,016 aseptic revision total knee arthroplasties reported to the Norwegian Arthroplasty Register between 1994 and 2011. Revisions done for infections were not included. Kaplan-Meier and Cox regression analyses were used to assess the survival rate and the relative risk of re-revision with all causes of re-revision as endpoint. Results 145 knees failed after revision total knee arthroplasty. Deep infection was the most frequent cause of re-revision (28%), followed by instability (26%), loose tibial component (17%), and pain (10%). The cumulative survival rate for revision total knee arthroplasties was 85% at 5 years, 78% at 10 years, and 71% at 15 years. Revision total knee arthroplasties with exchange of the femoral or tibial component exclusively had a higher risk of re-revision (RR = 1.7) than those with exchange of the whole prosthesis. The risk of re-revision was higher for men (RR = 2.0) and for patients aged less than 60 years (RR = 1.6). Interpretation In terms of implant survival, revision of the whole implant was better than revision of 1 component only. Young age and male sex were risk factors for re-revision. Deep infection was the most frequent cause of failure of revision of aseptic total knee arthroplasties. PMID:25267502

  19. HEDR modeling approach: Revision 1

    SciTech Connect

    Shipler, D.B.; Napier, B.A.

    1994-05-01

    This report is a revision of the previous Hanford Environmental Dose Reconstruction (HEDR) Project modeling approach report. This revised report describes the methods used in performing scoping studies and estimating final radiation doses to real and representative individuals who lived in the vicinity of the Hanford Site. The scoping studies and dose estimates pertain to various environmental pathways during various periods of time. The original report discussed the concepts under consideration in 1991. The methods for estimating dose have been refined as understanding of existing data, the scope of pathways, and the magnitudes of dose estimates were evaluated through scoping studies.

  20. Revised evaluations for ENDF/B-VI Revision 2

    SciTech Connect

    Wright, R.Q.

    1993-03-01

    The purpose of this paper is to report on revised cross-section evaluations for 17 nuclides that have been prepared for ENDF/B-VI Revision 2. The nuclides considered include five fission products and various isotopes of cadmium and hafnium. The previous ENDF/B-VI evaluations for these 17 nuclides were carried over from ENDF/B-V and were completed in the 1974--1980 time period. By utilizing the experimental data that have become available since 1980 the revised evaluations will result in significant improvements in the evaluated nuclear data files. The primary emphasis was placed on the resolved and unresolved resonance regions, but new experimental data were also used to improve the cross sections for energies above the unresolved resonance region. Negative elastic scattering cross sections were encountered in some of the previous evaluations; since the revised evaluations use multilevel Breit-Wigner (MLBW) parameters, rather than single-level Breit-Wigner (SLBW), this problem is eliminated.

  1. The Optical Extragalactic Background Light: Revisions and Further Comments

    NASA Astrophysics Data System (ADS)

    Bernstein, Rebecca A.

    2007-09-01

    We revise the measurements in our previous work of foreground zodiacal light (ZL) and diffuse Galactic light (DGL) that were used to measure the extragalactic background light (EBL). These changes result in a decrease of 8 and an increase of 0.3 in units of 10-9 ergs s-1 cm-2 sr-1 Å-1 (``cgs'' units) in the ZL and DGL flux, respectively. We therefore obtain revised values for the EBL of 6+/-4, 10+/-5, and 7+/-4 cgs in the HST WFPC2 U (F300W), V (F555W), and I (F814W) bands, respectively, from sources fainter than mV~23 AB mag. The revisions are dominated by the details of the tropospheric scattering models used to measure the ZL. We discuss these results in the context of faint number counts and diffuse EBL measurements at other wavelengths. In particular, we note that unless the slope of the galaxy counts increases beyond mV~30 AB mag, unresolved sources will contribute <0.2 cgs, which is far below the uncertainties achievable for any diffuse EBL measurement in the foreseeable future. Therefore, the best constraints on faint sources come from the resolved sources themselves. As in our earlier work, models are still required to derive the bolometric EBL (0.1-1000 μm) due to uncertainties in the mid-infrared consequently, our previous discussions of the bolometric EBL are not affected by the revisions presented here. Finally, we discuss the nature of the extended point-spread function (PSF) of ground-based telescopes and its impact on surface brightness measurements. In particular, we show that the slope and amplitude of extended PSFs vary considerably between telescopes and with time. We find no conclusive, single cause of extended PSFs, although atmospheric scattering is ruled out.

  2. Diet History Questionnaire: Database Revision History

    Cancer.gov

    The following details all additions and revisions made to the DHQ nutrient and food database. This revision history is provided as a reference for investigators who may have performed analyses with a previous release of the database.

  3. Revision Process and Practice: A Kindergarten Experience

    ERIC Educational Resources Information Center

    Chase, Maggie

    2012-01-01

    Many educators teach students that are reluctant about the revisions process in writing. However, this longitudinal study follows a group of students from kindergarten through 8th grade who embraced the importance of the revision process. (Contains 8 figures.)

  4. Transcriptional analysis of micronutrient zinc-associated response for enhanced carbohydrate utilization and earlier solventogenesis in Clostridium acetobutylicum

    PubMed Central

    Wu, You-Duo; Xue, Chuang; Chen, Li-Jie; Wan, Hui-Hui; Bai, Feng-Wu

    2015-01-01

    The micronutrient zinc plays vital roles in ABE fermentation by Clostridium acetobutylicum. In order to elucidate the zinc-associated response for enhanced glucose utilization and earlier solventogenesis, transcriptional analysis was performed on cells grown in glucose medium at the exponential growth phase of 16 h without/with supplementary zinc. Correspondingly, the gene glcG (CAC0570) encoding a glucose-specific PTS was significantly upregulated accompanied with the other two genes CAC1353 and CAC1354 for glucose transport in the presence of zinc. Additionally, genes involved in the metabolisms of six other carbohydrates (maltose, cellobiose, fructose, mannose, xylose and arabinose) were differentially expressed, indicating that the regulatory effect of micronutrient zinc is carbohydrate-specific with respects to the improved/inhibited carbohydrate utilization. More importantly, multiple genes responsible for glycolysis (glcK and pykA), acidogenesis (thlA, crt, etfA, etfB and bcd) and solventogenesis (ctfB and bdhA) of C. acetobutylicum prominently responded to the supplementary zinc at differential expression levels. Comparative analysis of intracellular metabolites revealed that the branch node intermediates such as acetyl-CoA, acetoacetyl-CoA, butyl-CoA, and reducing power NADH remained relatively lower whereas more ATP was generated due to enhanced glycolysis pathway and earlier initiation of solventogenesis, suggesting that the micronutrient zinc-associated response for the selected intracellular metabolisms is significantly pleiotropic. PMID:26586044

  5. Retrospective study of reasons for improved survival in patients with breast cancer in east Anglia: earlier diagnosis or better treatment.

    PubMed Central

    Stockton, D.; Davies, T.; Day, N.; McCann, J.

    1997-01-01

    OBJECTIVES: To investigate the recent fall in mortality from breast cancer in England and Wales, and to determine the relative contributions of improvements in treatment and earlier detection of tumours. DESIGN: Retrospective study of all women with breast cancer registered by the East Anglian cancer registry and diagnosed between 1982 and 1989. SUBJECTS: 3965 patients diagnosed 1982-5 compared with 4665 patients diagnosed 1986-9, in three age groups 0-49, 50-64, > or = 65 years, with information on stage at diagnosis and survival. MAIN OUTCOME MEASURES: Three year relative survival rates by time period, age group, and stage; relative hazard ratios for each time period and age group derived from Cox's proportional hazards model, adjusted for single year of age and stage. RESULTS: Survival improved in the later time period, although there was little stage specific improvement. The proportion of early stage tumours increased especially in the 50-64 year age group, and adjustment for stage accounted for over half of the improvement in survival in women aged under 65 years. CONCLUSION: Over half of the drop in mortality in women aged under 65 years seems to be attributable to earlier detection of tumours, which has been observed since the mid-1980s. This could have resulted from an increase in breast awareness predating the start of the breast screening programme. PMID:9056796

  6. Retinol supplementation and mesothelioma incidence in workers earlier exposed to blue asbestos (Crocidolite) at Wittenoom, Western Australia.

    PubMed

    Alfonso, Helman S; Reid, Alison; de Klerk, Nicholas H; Olsen, Nola; Mina, Robin; Ambrosini, Gina L; Beilby, John; Berry, Geoffrey; Musk, Bill A W

    2010-09-01

    Owing to the high rates of malignant mesothelioma in workers exposed to crocidolite earlier at Wittenoom and evidence of protection against cancer by vitamin A, a population-based cancer prevention programme providing retinol supplements (25 000 IU/day) was commenced in 1990. The former workers at Wittenoom known to be alive and living in Western Australia in June 1990 constitute the study population. The participants were classified into two groups: those who received supplemental retinol (intervention group) and those who received none (comparison group). The relative rate of mesothelioma for those receiving retinol was estimated using Cox regression, adjusting for cumulative asbestos exposure and age at first exposure to asbestos. Nine hundred and twenty-eight former Wittenoom workers received retinol at some stage of the programme, whereas 1471 workers never received retinol (comparison group). Those who received retinol were younger, had a greater exposure to asbestos and smoked less than the comparison group. There were 65 cases of mesothelioma in the retinol group and 88 in the comparison group. After adjustment, the hazard ratio was 0.99 (95% confidence interval=0.70-1.41). This result did not alter when the participants who received only retinol once or those who received beta-carotene earlier were excluded from the analysis. In conclusion, this study provides little support for possible preventive effects of retinol against mesothelioma in workers exposed to blue asbestos.

  7. Transcriptional analysis of micronutrient zinc-associated response for enhanced carbohydrate utilization and earlier solventogenesis in Clostridium acetobutylicum.

    PubMed

    Wu, You-Duo; Xue, Chuang; Chen, Li-Jie; Wan, Hui-Hui; Bai, Feng-Wu

    2015-11-20

    The micronutrient zinc plays vital roles in ABE fermentation by Clostridium acetobutylicum. In order to elucidate the zinc-associated response for enhanced glucose utilization and earlier solventogenesis, transcriptional analysis was performed on cells grown in glucose medium at the exponential growth phase of 16 h without/with supplementary zinc. Correspondingly, the gene glcG (CAC0570) encoding a glucose-specific PTS was significantly upregulated accompanied with the other two genes CAC1353 and CAC1354 for glucose transport in the presence of zinc. Additionally, genes involved in the metabolisms of six other carbohydrates (maltose, cellobiose, fructose, mannose, xylose and arabinose) were differentially expressed, indicating that the regulatory effect of micronutrient zinc is carbohydrate-specific with respects to the improved/inhibited carbohydrate utilization. More importantly, multiple genes responsible for glycolysis (glcK and pykA), acidogenesis (thlA, crt, etfA, etfB and bcd) and solventogenesis (ctfB and bdhA) of C. acetobutylicum prominently responded to the supplementary zinc at differential expression levels. Comparative analysis of intracellular metabolites revealed that the branch node intermediates such as acetyl-CoA, acetoacetyl-CoA, butyl-CoA, and reducing power NADH remained relatively lower whereas more ATP was generated due to enhanced glycolysis pathway and earlier initiation of solventogenesis, suggesting that the micronutrient zinc-associated response for the selected intracellular metabolisms is significantly pleiotropic.

  8. Field evidence for earlier leaf-out dates in alpine grassland on the eastern Tibetan Plateau from 1990 to 2006.

    PubMed

    Zhou, H K; Yao, B Q; Xu, W X; Ye, X; Fu, J J; Jin, Y X; Zhao, X Q

    2014-08-01

    Worldwide, many plant species are experiencing an earlier onset of spring phenophases due to climate warming. Rapid recent temperature increases on the Tibetan Plateau (TP) have triggered changes in the spring phenology of the local vegetation. However, remote sensing studies of the land surface phenology have reached conflicting interpretations about green-up patterns observed on the TP since the mid-1990s. We investigated this issue using field phenological observations from 1990 to 2006, for 11 dominant plants on the TP at the levels of species, families (Gramineae-grasses and Cyperaceae-sedges) and vegetation communities (alpine meadow and alpine steppe). We found a significant trend of earlier leaf-out dates for one species (Koeleria cristata). The leaf-out dates of both Gramineae and Cyperaceae had advanced (the latter significantly, starting an average of 9 days later per year than the former), but the correlation between them was significant. The leaf-out dates of both vegetation communities also advanced, but the pattern was only significant in the alpine meadow. This study provides the first field evidence of advancement in spring leaf phenology on the TP and suggests that the phenology of the alpine steppe can differ from that of the alpine meadow. These findings will be useful for understanding ecosystem responses to climate change and for grassland management on the TP. PMID:25099960

  9. Automated revision of CLIPS rule-bases

    NASA Technical Reports Server (NTRS)

    Murphy, Patrick M.; Pazzani, Michael J.

    1994-01-01

    This paper describes CLIPS-R, a theory revision system for the revision of CLIPS rule-bases. CLIPS-R may be used for a variety of knowledge-base revision tasks, such as refining a prototype system, adapting an existing system to slightly different operating conditions, or improving an operational system that makes occasional errors. We present a description of how CLIPS-R revises rule-bases, and an evaluation of the system on three rule-bases.

  10. Air Pollution Primer. Revised Education.

    ERIC Educational Resources Information Center

    Corman, Rena

    This revised and updated book is written to inform the citizens on the nature, causes, and effects of air pollution. It is written in terms familiar to the layman with the purpose of providing knowledge and motivation to spur community action on clean air policies. Numerous charts and drawings are provided to support discussion of air pollution…

  11. Revised Accounting for Business Combinations

    ERIC Educational Resources Information Center

    Wilson, Arlette C.; Key, Kimberly

    2008-01-01

    The Financial Accounting Standards Board (FASB) has recently issued Statement of Financial Accounting Standards No. 141 (Revised 2007) Business Combinations. The object of this Statement is to improve the relevance, representational faithfulness, and comparability of reported information about a business combination and its effects. This Statement…

  12. Ethical considerations in revision rhinoplasty.

    PubMed

    Wayne, Ivan

    2012-08-01

    The problems that arise when reviewing another surgeon's work, the financial aspects of revision surgery, and the controversies that present in marketing and advertising will be explored. The technological advances of computer imaging and the Internet have introduced new problems that require our additional consideration.

  13. Collaborative Revision on a Computer.

    ERIC Educational Resources Information Center

    Cornell, Cynthia; Newton, Robert

    A study investigated the effects of using a computer image projected on a large screen to teach revision to college students. Subjects, 19 students at DePauw University, enrolled in a writing intensive literature course in a Writing across the Curriculum program, were divided into test and control groups. It was hypothesized that the modeling of…

  14. Copyright Revision and the University.

    ERIC Educational Resources Information Center

    Boucher, Pierre-Yves

    Proposed revisions of Canada's copyright law are criticized for their failure to address some basic issues of creator's rights, and the academic community's legal responsibility in the infringement of copyrights is discussed. It is argued that the writers of the proposed changes have treated copyrights as property rights without due consideration…

  15. Modern Indian Psychology. Revised Edition.

    ERIC Educational Resources Information Center

    Bryde, John F.

    Written on the basis of senior Indian verbal relatings collected over a 23-year span, this revised edition on modern Indian psychology incorporates suggestions from Indian students and their teachers, Indian and non-Indian social studies experts, and other Indian people. The book contains 6 major divisions: (1) "Culture and Indian Values" relates…

  16. Ethnic Awareness Through Curriculum Revision.

    ERIC Educational Resources Information Center

    Giordano, Michael Joseph

    This study compared the attitudes towards ethnic groups of high school students enrolled in a standard U.S. history course with the attitudes of students enrolled in a revised U.S. history course which emphasized ethnic awareness. A review of the literature indicated a need for ethnic awareness. The experimental group consisted of 16 students; the…

  17. Guidelines for Curriculum Development. Revised.

    ERIC Educational Resources Information Center

    Kistler, K.; And Others

    The curriculum development process explained in this booklet was first implemented at College of the Redwoods in May 1986 and then revised in June 1989. First, information on the college's Curriculum Committee is provided, indicating that the committee was formed to plan credit/non-credit courses; evaluate and approve additions, modifications, or…

  18. Humeral windows in revision total elbow arthroplasty

    PubMed Central

    Salama, Amir; Stanley, David

    2016-01-01

    The use of cortical windows for revision elbow arthroplasty has not previously been widely reported. Their use aids safe revision of a well fixed humeral prosthesis and can be used in the setting of dislocation, periprosthetic fracture or aseptic loosening of the ulnar component. We describe our technique and results of cortical windows in the distal humerus for revision elbow arthroplasty surgery. PMID:27583011

  19. Humeral windows in revision total elbow arthroplasty.

    PubMed

    Peach, Chris A; Salama, Amir; Stanley, David

    2016-04-01

    The use of cortical windows for revision elbow arthroplasty has not previously been widely reported. Their use aids safe revision of a well fixed humeral prosthesis and can be used in the setting of dislocation, periprosthetic fracture or aseptic loosening of the ulnar component. We describe our technique and results of cortical windows in the distal humerus for revision elbow arthroplasty surgery. PMID:27583011

  20. "SOAR" to the Stars through Revising.

    ERIC Educational Resources Information Center

    Johnson, Jan

    1995-01-01

    Explains how a teacher uses the acronym SOAR (Sentences Organized and Revised) as the core of a game designed to motivate a class to revise their work through the promise of popcorn, free time, or snacks for their revision work. Describes a worksheet that forces students to pay attention to various parts of their paper. (TB)

  1. 24 CFR 968.225 - Budget revisions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Budget revisions. 968.225 Section... Fewer Than 250 Units) § 968.225 Budget revisions. (a) A PHA shall not incur any modernization cost in excess of the total HUD-approved CIAP budget. A PHA shall submit a budget revision, in a form...

  2. The evolution of a manual revision.

    PubMed

    Luzinski, Craig

    2012-10-01

    This month, the director of the Magnet Recognition Program® provides an in-depth overview of the Magnet Recognition Program's Application Manual revision process. The history of the 2005 Manual revision, an evidence-based review of the literature, and revisions to the 2008 Manual are key elements of this article. PMID:22968115

  3. Revision Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Wilde, Jeffrey; Bedi, Asheesh; Altchek, David W.

    2014-01-01

    Context: Reconstruction of the anterior cruciate ligament (ACL) is one of the most common surgical procedures, with more than 200,000 ACL tears occurring annually. Although primary ACL reconstruction is a successful operation, success rates still range from 75% to 97%. Consequently, several thousand revision ACL reconstructions are performed annually and are unfortunately associated with inferior clinical outcomes when compared with primary reconstructions. Evidence Acquisition: Data were obtained from peer-reviewed literature through a search of the PubMed database (1988-2013) as well as from textbook chapters and surgical technique papers. Study Design: Clinical review. Level of Evidence: Level 4. Results: The clinical outcomes after revision ACL reconstruction are largely based on level IV case series. Much of the existing literature is heterogenous with regard to patient populations, primary and revision surgical techniques, concomitant ligamentous injuries, and additional procedures performed at the time of the revision, which limits generalizability. Nevertheless, there is a general consensus that the outcomes for revision ACL reconstruction are inferior to primary reconstruction. Conclusion: Excellent results can be achieved with regard to graft stability, return to play, and functional knee instability but are generally inferior to primary ACL reconstruction. A staged approach with autograft reconstruction is recommended in any circumstance in which a single-stage approach results in suboptimal graft selection, tunnel position, graft fixation, or biological milieu for tendon-bone healing. Strength-of-Recommendation Taxonomy (SORT): Good results may still be achieved with regard to graft stability, return to play, and functional knee instability, but results are generally inferior to primary ACL reconstruction: Level B. PMID:25364483

  4. Wind Magnetic Clouds for 2010-2012: Model Parameter Fittings, Associated Shock Waves, and Comparisons to Earlier Periods

    NASA Technical Reports Server (NTRS)

    Lepping, R. P.; Wu, C.-C.; Berdichevsky, D. B.; Szabo, A.

    2015-01-01

    We fitted the parameters of magnetic clouds (MCs) as identified in the Wind spacecraft data from early 2010 to the end of 2012 using the model of Lepping, Jones, and Burlaga (J. Geophys. Res. 95, 1195, 1990). The interval contains 48 MCs and 39 magnetic cloud-like (MCL) events. This work is a continuation of MC model fittings of the earlier Wind sets, including those in a recent publication, which covers 2007 to 2009. This period (2010 - 2012) mainly covers the maximum portion of Solar Cycle 24. Between the previous and current interval, we document 5.7 years of MCs observations. For this interval, the occurrence frequency of MCs markedly increased in the last third of the time. In addition, over approximately the last six years, the MC type (i.e. the profile of the magnetic-field direction within an MC, such as North-to-South, South-to-North, all South) dramatically evolved to mainly North-to-South types when compared to earlier years. Furthermore, this evolution of MC type is consistent with global solar magnetic-field changes predicted by Bothmer and Rust (Coronal Mass Ejections, 139, 1997). Model fit parameters for the MCs are listed for 2010 - 2012. For the 5.7 year interval, the observed MCs are found to be slower, weaker in estimated axial magnetic-field intensity, and shorter in duration than those of the earlier 12.3 years, yielding much lower axial magnetic-field fluxes. For about the first half of this 5.7 year period, i.e. up to the end of 2009, there were very few associated MC-driven shock waves (distinctly fewer than the long-term average of about 50 % of MCs). But since 2010, such driven shocks have increased markedly, reflecting similar statistics as the long-term averages. We estimate that 56 % of the total observed MCs have upstream shocks when the full interval of 1995 - 2012 is considered. However, only 28 % of the total number of MCLs have driven shocks over the same period. Some interplanetary shocks during the 2010 - 2012 interval are seen

  5. Effects of earlier sea ice breakup on survival and population size of polar bears in western Hudson Bay

    USGS Publications Warehouse

    Regehr, E.V.; Lunn, N.J.; Amstrup, Steven C.; Stirling, I.

    2007-01-01

    Some of the most pronounced ecological responses to climatic warming are expected to occur in polar marine regions, where temperature increases have been the greatest and sea ice provides a sensitive mechanism by which climatic conditions affect sympagic (i.e., with ice) species. Population-level effects of climatic change, however, remain difficult to quantify. We used a flexible extension of Cormack-Jolly-Seber capture-recapture models to estimate population size and survival for polar bears (Ursus maritimus), one of the most ice-dependent of Arctic marine mammals. We analyzed data for polar bears captured from 1984 to 2004 along the western coast of Hudson Bay and in the community of Churchill, Manitoba, Canada. The Western Hudson Bay polar bear population declined from 1,194 (95% CI = 1,020-1,368) in 1987 to 935 (95% CI = 794-1,076) in 2004. Total apparent survival of prime-adult polar bears (5-19 yr) was stable for females (0.93; 95% CI = 0.91-0.94) and males (0.90; 95% CI = 0.88-0.91). Survival of juvenile, subadult, and senescent-adult polar bears was correlated with spring sea ice breakup date, which was variable among years and occurred approximately 3 weeks earlier in 2004 than in 1984. We propose that this correlation provides evidence for a causal association between earlier sea ice breakup (due to climatic warming) and decreased polar bear survival. It may also explain why Churchill, like other communities along the western coast of Hudson Bay, has experienced an increase in human-polar bear interactions in recent years. Earlier sea ice breakup may have resulted in a larger number of nutritionally stressed polar bears, which are encroaching on human habitations in search of supplemental food. Because western Hudson Bay is near the southern limit of the species' range, our findings may foreshadow the demographic responses and management challenges that more northerly polar bear populations will experience if climatic warming in the Arctic continues as

  6. Wind Magnetic Clouds for 2010 - 2012: Model Parameter Fittings, Associated Shock Waves, and Comparisons to Earlier Periods

    NASA Astrophysics Data System (ADS)

    Lepping, R. P.; Wu, C.-C.; Berdichevsky, D. B.; Szabo, A.

    2015-08-01

    We fitted the parameters of magnetic clouds (MCs) as identified in the Wind spacecraft data from early 2010 to the end of 2012 using the model of Lepping, Jones, and Burlaga ( J. Geophys. Res. 95, 1195, 1990). The interval contains 48 MCs and 39 magnetic cloud-like (MCL) events. This work is a continuation of MC model fittings of the earlier Wind sets, including those in a recent publication, which covers 2007 to 2009. This period (2010 - 2012) mainly covers the maximum portion of Solar Cycle 24. Between the previous and current interval, we document 5.7 years of MCs observations. For this interval, the occurrence frequency of MCs markedly increased in the last third of the time. In addition, over approximately the last six years, the MC type ( i.e. the profile of the magnetic-field direction within an MC, such as North-to-South, South-to-North, all South) dramatically evolved to mainly North-to-South types when compared to earlier years. Furthermore, this evolution of MC type is consistent with global solar magnetic-field changes predicted by Bothmer and Rust ( Coronal Mass Ejections, 139, 1997). Model fit parameters for the MCs are listed for 2010 - 2012. For the 5.7 year interval, the observed MCs are found to be slower, weaker in estimated axial magnetic-field intensity, and shorter in duration than those of the earlier 12.3 years, yielding much lower axial magnetic-field fluxes. For about the first half of this 5.7 year period, i.e. up to the end of 2009, there were very few associated MC-driven shock waves (distinctly fewer than the long-term average of about 50 % of MCs). But since 2010, such driven shocks have increased markedly, reflecting similar statistics as the long-term averages. We estimate that 56 % of the total observed MCs have upstream shocks when the full interval of 1995 - 2012 is considered. However, only 28 % of the total number of MCLs have driven shocks over the same period. Some interplanetary shocks during the 2010 - 2012 interval are

  7. [Diagnosis of Ramsey Hunt syndrome is both simple and difficult. The viral attack is more extensive than expected earlier].

    PubMed

    Hydén, D; Roberg, M

    2000-03-01

    In Ramsay Hunt's syndrome (herpes zoster of the head and neck in combination with facial palsy), the vesicles often appear on the external ear (herpes zoster oticus) but they can also be found on the exterior of the neck. Serologically verified cases without vesicles occur (zoster sine herpeticum). Complications from the eighth cranial nerve (hearing loss and vertigo) are common. MR and PCR studies show a more extensive viral attack than was earlier believed to be the case. Due to the risk of remaining cranial nerve dysfunctions, as exemplified in a case report, antiviral treatment is indicated, in severe cases combined with corticosteroids. The potential value of varicella vaccination to reduce zoster complications is discussed.

  8. Combining in Vitro Diagnostics with in Vivo Imaging for Earlier Detection of Pancreatic Ductal Adenocarcinoma: Challenges and Solutions.

    PubMed

    Laeseke, Paul F; Chen, Ru; Jeffrey, R Brooke; Brentnall, Teresa A; Willmann, Jürgen K

    2015-12-01

    Pancreatic ductal adenocarcinoma (PDAC) is the fourth-leading cause of cancer-related death in the United States and is associated with a dismal prognosis, particularly when diagnosed at an advanced stage. Overall survival is significantly improved if PDAC is detected at an early stage prior to the onset of symptoms. At present, there is no suitable screening strategy for the general population. Available diagnostic serum markers are not sensitive or specific enough, and clinically available imaging modalities are inadequate for visualizing early-stage lesions. In this article, the role of currently available blood biomarkers and imaging tests for the early detection of PDAC will be reviewed. Also, the emerging biomarkers and molecularly targeted imaging agents being developed to improve the specificity of current imaging modalities for PDAC will be discussed. A strategy incorporating blood biomarkers and molecularly targeted imaging agents could lead to improved screening and earlier detection of PDAC in the future. (©) RSNA, 2015. PMID:26599925

  9. Combining in Vitro Diagnostics with in Vivo Imaging for Earlier Detection of Pancreatic Ductal Adenocarcinoma: Challenges and Solutions.

    PubMed

    Laeseke, Paul F; Chen, Ru; Jeffrey, R Brooke; Brentnall, Teresa A; Willmann, Jürgen K

    2015-12-01

    Pancreatic ductal adenocarcinoma (PDAC) is the fourth-leading cause of cancer-related death in the United States and is associated with a dismal prognosis, particularly when diagnosed at an advanced stage. Overall survival is significantly improved if PDAC is detected at an early stage prior to the onset of symptoms. At present, there is no suitable screening strategy for the general population. Available diagnostic serum markers are not sensitive or specific enough, and clinically available imaging modalities are inadequate for visualizing early-stage lesions. In this article, the role of currently available blood biomarkers and imaging tests for the early detection of PDAC will be reviewed. Also, the emerging biomarkers and molecularly targeted imaging agents being developed to improve the specificity of current imaging modalities for PDAC will be discussed. A strategy incorporating blood biomarkers and molecularly targeted imaging agents could lead to improved screening and earlier detection of PDAC in the future. (©) RSNA, 2015.

  10. Warmer waters in the Northern Territory--herald an earlier onset to the annual Chironex fleckeri Stinger season.

    PubMed

    Jacups, Susan P

    2010-08-01

    The discovery that Chironex fleckeri occurs annually in northern Australia occurred long ago, possibly before written records were available by local indigenous people, however, to date the precision of this yearly phenomenon is still not fully understood. Sea surface temperature (SST) appears to be a determining factor signaling the "arrival" of C. fleckeri each year. Anthropogenic climate change modeling predicts global rises in SST. Rises in SST may result in an earlier "arrival" of C. fleckeri during the dry season, possibly necessitating extension of the official Northern Territory stinger season to commence in September (currently October through to June). This short report presents data to support this hypothesis, facilitating policy makers with an environmental cue upon which changes to current stinger season can be based--prior to painful and potentially life-threatening presentations.

  11. Reduction of Glucose Metabolism in Olfactory Bulb is an Earlier Alzheimer's Disease-related Biomarker in 5XFAD Mice

    PubMed Central

    Xiao, Nai-An; Zhang, Jing; Zhou, Meng; Wei, Zhen; Wu, Xi-Lin; Dai, Xiao-Man; Zhu, Yuan-Gui; Chen, Xiao-Chun

    2015-01-01

    Background: Early diagnosis assumes a vital role in an effective treatment of Alzheimer's disease (AD). Most of the current studies can only make an AD diagnosis after the manifestation of typical clinical symptoms. The present study aimed to investigate typical and other biomarkers of AD to find a possible early biomarker. Methods: A total of 14 5XFAD mice (at 3 and 6 months old), with 14 age-matched wild-type (WT) mice as control, were enrolled in this case-control study. Morris water maze test was performed to evaluate the cognitive function; buried food pellet test and olfactory maze test were employed to investigate the olfactory function; immunofluorescence to detect amyloid deposition and positron emission tomography to examine 2-deoxy-2-(18 F) fluoro-D-glucose ([18 F]-FDG) uptake in the hippocampus and cerebral cortex. Results: With the increasing age, cognitive performance (P = 0.0262) and olfactory function were significantly deteriorated (day 1 P = 0.0012, day 2 P = 0.0031, day 3 P = 0.0160, respectively) and the (18 F)-FDG uptake was markedly decreased in multi-cerebral regions including the olfactory bulb (P < 0.0001), hippocampus (P = 0.0121), and cerebral cortex (P < 0.0001). Of note, in 3-month-old 5XFAD mice, a significant decline of (18 F)-FDG uptake in the olfactory bulb was found when compared with that of age-matched WT mice (P = 0.023) while no significant difference was present when the uptakes in other cerebral regions were compared. Conclusions: The decline of (18 F)-FDG uptake in the olfactory bulb occurs earlier than other incidents, serving as an earlier in vivo biological marker of AD in 5XFAD mice and making early diagnosis of AD possibly. PMID:26265617

  12. Earlier visual N1 latencies in expert video-game players: a temporal basis of enhanced visuospatial performance?

    PubMed

    Latham, Andrew J; Patston, Lucy L M; Westermann, Christine; Kirk, Ian J; Tippett, Lynette J

    2013-01-01

    Increasing behavioural evidence suggests that expert video game players (VGPs) show enhanced visual attention and visuospatial abilities, but what underlies these enhancements remains unclear. We administered the Poffenberger paradigm with concurrent electroencephalogram (EEG) recording to assess occipital N1 latencies and interhemispheric transfer time (IHTT) in expert VGPs. Participants comprised 15 right-handed male expert VGPs and 16 non-VGP controls matched for age, handedness, IQ and years of education. Expert VGPs began playing before age 10, had a minimum 8 years experience, and maintained playtime of at least 20 hours per week over the last 6 months. Non-VGPs had little-to-no game play experience (maximum 1.5 years). Participants responded to checkerboard stimuli presented to the left and right visual fields while 128-channel EEG was recorded. Expert VGPs responded significantly more quickly than non-VGPs. Expert VGPs also had significantly earlier occipital N1s in direct visual pathways (the hemisphere contralateral to the visual field in which the stimulus was presented). IHTT was calculated by comparing the latencies of occipital N1 components between hemispheres. No significant between-group differences in electrophysiological estimates of IHTT were found. Shorter N1 latencies may enable expert VGPs to discriminate attended visual stimuli significantly earlier than non-VGPs and contribute to faster responding in visual tasks. As successful video-game play requires precise, time pressured, bimanual motor movements in response to complex visual stimuli, which in this sample began during early childhood, these differences may reflect the experience and training involved during the development of video-game expertise, but training studies are needed to test this prediction.

  13. Earlier Visual N1 Latencies in Expert Video-Game Players: A Temporal Basis of Enhanced Visuospatial Performance?

    PubMed Central

    Latham, Andrew J.; Patston, Lucy L. M.; Westermann, Christine; Kirk, Ian J.; Tippett, Lynette J.

    2013-01-01

    Increasing behavioural evidence suggests that expert video game players (VGPs) show enhanced visual attention and visuospatial abilities, but what underlies these enhancements remains unclear. We administered the Poffenberger paradigm with concurrent electroencephalogram (EEG) recording to assess occipital N1 latencies and interhemispheric transfer time (IHTT) in expert VGPs. Participants comprised 15 right-handed male expert VGPs and 16 non-VGP controls matched for age, handedness, IQ and years of education. Expert VGPs began playing before age 10, had a minimum 8 years experience, and maintained playtime of at least 20 hours per week over the last 6 months. Non-VGPs had little-to-no game play experience (maximum 1.5 years). Participants responded to checkerboard stimuli presented to the left and right visual fields while 128-channel EEG was recorded. Expert VGPs responded significantly more quickly than non-VGPs. Expert VGPs also had significantly earlier occipital N1s in direct visual pathways (the hemisphere contralateral to the visual field in which the stimulus was presented). IHTT was calculated by comparing the latencies of occipital N1 components between hemispheres. No significant between-group differences in electrophysiological estimates of IHTT were found. Shorter N1 latencies may enable expert VGPs to discriminate attended visual stimuli significantly earlier than non-VGPs and contribute to faster responding in visual tasks. As successful video-game play requires precise, time pressured, bimanual motor movements in response to complex visual stimuli, which in this sample began during early childhood, these differences may reflect the experience and training involved during the development of video-game expertise, but training studies are needed to test this prediction. PMID:24058667

  14. CHRNA5 Risk Variant Predicts Delayed Smoking Cessation and Earlier Lung Cancer Diagnosis—A Meta-Analysis

    PubMed Central

    Hung, Rayjean J.; Baker, Timothy; Horton, Amy; Culverhouse, Rob; Saccone, Nancy; Cheng, Iona; Deng, Bo; Han, Younghun; Hansen, Helen M.; Horsman, Janet; Kim, Claire; Lutz, Sharon; Rosenberger, Albert; Aben, Katja K.; Andrew, Angeline S.; Breslau, Naomi; Chang, Shen-Chih; Dieffenbach, Aida Karina; Dienemann, Hendrik; Frederiksen, Brittni; Han, Jiali; Hatsukami, Dorothy K.; Johnson, Eric O.; Pande, Mala; Wrensch, Margaret R.; McLaughlin, John; Skaug, Vidar; van der Heijden, Henricus F.; Wampfler, Jason; Wenzlaff, Angela; Woll, Penella; Zienolddiny, Shanbeh; Bickeböller, Heike; Brenner, Hermann; Duell, Eric J.; Haugen, Aage; Heinrich, Joachim; Hokanson, John E.; Hunter, David J.; Kiemeney, Lambertus A.; Lazarus, Philip; Le Marchand, Loic; Liu, Geoffrey; Mayordomo, Jose; Risch, Angela; Schwartz, Ann G.; Teare, Dawn; Wu, Xifeng; Wiencke, John K.; Yang, Ping; Zhang, Zuo-Feng; Spitz, Margaret R.; Kraft, Peter; Amos, Christopher I.; Bierut, Laura J.

    2015-01-01

    Background: Recent meta-analyses show strong evidence of associations among genetic variants in CHRNA5 on chromosome 15q25, smoking quantity, and lung cancer. This meta-analysis tests whether the CHRNA5 variant rs16969968 predicts age of smoking cessation and age of lung cancer diagnosis. Methods: Meta-analyses examined associations between rs16969968, age of quitting smoking, and age of lung cancer diagnosis in 24 studies of European ancestry (n = 29 072). In each dataset, we used Cox regression models to evaluate the association between rs16969968 and the two primary phenotypes (age of smoking cessation among ever smokers and age of lung cancer diagnosis among lung cancer case patients) and the secondary phenotype of smoking duration. Heterogeneity across studies was assessed with the Cochran Q test. All statistical tests were two-sided. Results: The rs16969968 allele (A) was associated with a lower likelihood of smoking cessation (hazard ratio [HR] = 0.95, 95% confidence interval [CI] = 0.91 to 0.98, P = .0042), and the AA genotype was associated with a four-year delay in median age of quitting compared with the GG genotype. Among smokers with lung cancer diagnoses, the rs16969968 genotype (AA) was associated with a four-year earlier median age of diagnosis compared with the low-risk genotype (GG) (HR = 1.08, 95% CI = 1.04 to 1.12, P = 1.1*10–5). Conclusion: These data support the clinical significance of the CHRNA5 variant rs16969968. It predicts delayed smoking cessation and an earlier age of lung cancer diagnosis in this meta-analysis. Given the existing evidence that this CHRNA5 variant predicts favorable response to cessation pharmacotherapy, these findings underscore the potential clinical and public health importance of rs16969968 in CHRNA5 in relation to smoking cessation success and lung cancer risk. PMID:25873736

  15. Earlier breeding, lower success: does the spatial scale of climatic conditions matter in a migratory passerine bird?

    PubMed

    Grimm, Annegret; Weiß, Brigitte M; Kulik, Lars; Mihoub, Jean-Baptiste; Mundry, Roger; Köppen, Ulrich; Brueckmann, Tomas; Thomsen, Ruth; Widdig, Anja

    2015-12-01

    Following over 20 years of research on the climatic effects on biodiversity we now have strong evidence that climate change affects phenology, fitness, and distribution ranges of different taxa, including birds. Bird phenology likely responds to changes in local weather. It is also affected by climatic year-to-year variations on larger scales. Although such scale-related effects are common in ecology, most studies analyzing the effects of climate change were accomplished using climatic information on a single spatial scale. In this study, we aimed at determining the scale-dependent sensitivity of breeding phenology and success to climate change in a migratory passerine bird, the barn swallow (Hirundo rustica). For both annual broods, we investigated effects of local weather (local scale) and the North Atlantic Oscillation (NAO, large scale) on the timing of breeding and breeding success. Consistent with previous studies in migratory birds we found that barn swallows in Eastern Germany bred progressively earlier. At the same time, they showed reduced breeding success over time in response to recent climatic changes. Responses to climatic variation were observed on both local and large climatic scales, but they differed with respect to the ecological process considered. Specifically, we found that the timing of breeding was primarily influenced by large-scale NAO variations and to a lesser extent by local weather on the breeding grounds. Conversely, climatic conditions on the local scale affected breeding success, exclusively. The observed decrease in breeding success over years is likely a consequence of scale-related mismatches between climatic conditions during different breeding phases. This provides further evidence that a species' response of earlier breeding may not be enough to cope with climate change. Our results emphasize the importance of considering the response of ecological processes along different climatic scales in order to better understand the

  16. A 400-kyr record of millennial-scale carbonate preservation events in the Southern Ocean: Implications for Atlantic Meridional Overturning Circulation and atmospheric CO2

    NASA Astrophysics Data System (ADS)

    Hodell, D. A.; Vautravers, M. J.; Barker, S.; Charles, C.; Crowhurst, S.

    2014-12-01

    Hodell et al. (2001) suggested that carbonate preservation in the deep Cape Basin represented a qualitative, high-resolution record of the temporal evolution of the carbonate saturation state of the deep sea. The carbonate signal reflects both transient events in the redistribution of alkalinity and DIC in the deep ocean and steady-state mass balance processes. Here we re-analyzed the carbonate records of Sites 1089/TN057-21 using an Avaatech XRF core scanner and measured elemental variations at 2.5-mm resolution for the past 400 kyrs. Log Ca/Ti is highly correlated to weight percent carbonate content and other dissolution proxies and resolves millennial-scale events in carbonate preservation. A high-pass filter removes the low-frequency (orbital) variability in carbonate preservation, which is attributed mainly to steady-state mass balance processes. The high-frequency (suborbital) component reflects transient responses to the redistribution of carbonate ion that is related mainly to changing deep-water circulation. During the last glacial period, distinct millennial-scale increases in carbonate preservation in piston core TN057-21 occurred during times of enhanced Atlantic Meridional Overtunring Circulation (AMOC) (Barker et al., 2010; Barker and Diz, 2014), as supported by increases in benthic δ13C and less radiogenic ɛNd values. Carbonate preservation peaked particularly during long, warm interstadials in Greenland when a deep water mass with high carbonate ion concentration was formed in the North Atlantic. Export of NADW may have been greater than the Holocene during some of these events ("overshoots") and/or preformed carbonate ion concentrations in North Atlantic source areas may have been higher owing to lower atmospheric CO2 and less carbonate production in surface water. Each South Atlantic carbonate peak is associated with the start of Antarctic cooling and declining or leveling of atmospheric CO2, reflecting the signature of a thermal bipolar seesaw

  17. North Atlantic Deep Water Formation over the past 20 kyr as Recorded by Nd Isotopes in the Authigenic Fraction of Pelagic Sediments Along the Blake Ridge

    NASA Astrophysics Data System (ADS)

    Gutjahr, M.; Frank, M.; Stirling, C. H.; Keigwin, L. D.; Halliday, A. N.

    2005-12-01

    1700 m to ca. -10.5 in 4250 m. If these values are considered representative, then the Nd isotope composition of GNAIW was indeed different from the interglacial NADW by about 3 ɛNd units and could thus explain the observed South Atlantic Nd isotope variability over the past 20 kyr without a major weakening of deep water export from the North Atlantic.

  18. Variations in monsoonal rainfall over the last 21 kyr inferred from sedimentary organic matter in Tung-Yuan Pond, southern Taiwan

    NASA Astrophysics Data System (ADS)

    Yang, Tien-Nan; Lee, Teh-Quei; Meyers, Philip A.; Song, Sheng-Rong; Kao, Shuh-Ji; Löwemark, Ludvig; Chen, Rou-Fei; Chen, Huei-Fen; Wei, Kuo-Yen; Fan, Cheng-Wei; Shiau, Liang-Jian; Chiang, Hong-Wei; Chen, Yue-Gau; Chen, Min-Te

    2011-11-01

    Changes in paleorainfall intensity linked to the strength of the East Asian (EA) summer monsoon since 21 cal kyr BP are inferred from the organic matter contents of a 15-m sediment core from Tung-Yuan Pond in southern Taiwan. High total organic carbon/total nitrogen (TOC/TN) values in association with increased TOC content suggest that more soil-derived material containing terrestrial organic matter (OM) was delivered to the lake during periods of increased runoff associated with extensive precipitation that resulted from intensified summer monsoons, whereas low values indicate OM possessing a dominant algal origin during weakened summer monsoons. Rainfall intensity in terms of the proportion of terrestrial OM was high in four periods: the last deglaciation (˜17.2 to ˜12.2 ka), the early Holocene (˜10.6 to ˜8.6 ka), the middle Holocene Thermal Optimum (˜7.7 to ˜5 ka) and the late Holocene (˜4.2 to ˜2 ka), whereas it was low in the intervening time periods. High TOC/TN values coincide with peak values of summer insolation, and thus the strongest EA summer monsoon during the early and middle Holocene; small drops in these ratios correspond to increasing and decreasing solar radiation in the deglacial period and the late Holocene, respectively. The four intervals with low TOC/TN ratios, as well as episodic drops of the ratios during the deglaciation and the early and late Holocene are concordant with the late last glacial (˜21 to ˜17.2 ka), the Oldest (˜14.8 ka), the Older (˜13.3 ka) and the Younger Dryas (˜13 to ˜11.5 ka), the 8.2 cold event (˜8.6-7.7 ka) and a late Holocene cold event (˜5-4.2 ka), and suggest a weakened EA summer monsoon during these times. Moreover, high frequency hydrological variability occurred during the early Holocene, heavy rainfall persisted during the middle Holocene, and precipitation intensity generally diminished after ˜5 ka. The Tung-Yuan Pond sediment record indicates that the TOC/TN ratio can be used as a

  19. Clay mineral contribution from various provenances in the northern South China Sea over the past 400 kyr: implications for the East Asian monsoon evolution

    NASA Astrophysics Data System (ADS)

    Chen, Quan; Liu, Zhifei; Xie, Xin; Kissel, Catherine

    2014-05-01

    Clay mineralogy of Core MD12-3432 taken at 2125 m water depth (CIRCEA cruise on board the R.V. Marion Dufresne, IPEV) in the northern South China Sea was investigated in order to understand the time series contribution of terrigenous sediments from various provenances. With calibration of a low-resolution analysis on carbonate concentration and major elements, we converted the XRF core scanned calcium data into a high-resolution carbonate content records. Through referring to the well-dated carbonate record of nearby Core MD05-2904, we established a reliable age model, indicating about 400 kyr ago at the bottom of Core MD12-3432. The clay mineral assemblage is dominated by smectite (23-59%) and illite (22-43%), with minor chlorite (13-27%) and kaolinite (4-13%). The time series variation of clay mineral assemblages indicates strong glacial-interglacial cyclicity. In general, the variation in smectite content is similar to that of carbonate concentration, with higher values during interglacials than during glacials, while illite and chlorite contents showing opposite patterns. The change in kaolinite content shows an independent pattern with high values during glacials, corresponding well with the illite crystallinity variation. The provenance analysis of these clay minerals suggests three end-member sources: all smectites derive from Luzon, all kaolinites originate from the Pearl River, and illite and chlorite are coming from both the Pearl River and Taiwan. Using the linear separation method of illite crystallinity, a time series of the clay mineral contribution from the three major provenances to the northern South China Sea was reconstructed. Combined with spectral analyses, we suggest the clay mineral contribution from Pearl River was mainly influenced by sea level change, while the East Asian summer monsoon controlled the contribution from Luzon. The strong precipitation rate related to intensive East Asian summer monsoon would have enhanced the denudation and

  20. Stability of rift axis magma reservoirs: Spatial and temporal evolution of magma supply in the Dabbahu rift segment (Afar, Ethiopia) over the past 30 kyr

    NASA Astrophysics Data System (ADS)

    Medynski, S.; Pik, R.; Burnard, P.; Vye-Brown, C.; France, L.; Schimmelpfennig, I.; Whaler, K.; Johnson, N.; Benedetti, L.; Ayelew, D.; Yirgu, G.

    2015-01-01

    Unravelling the volcanic history of the Dabbahu/Manda Hararo rift segment in the Afar depression (Ethiopia) using a combination of cosmogenic (36Cl and 3He) surface exposure dating of basaltic lava-flows, field observations, geological mapping and geochemistry, we show in this paper that magmatic activity in this rift segment alternates between two distinct magma chambers. Recent activity in the Dabbahu rift (notably the 2005-2010 dyking crises) has been fed by a seismically well-identified magma reservoir within the rift axis, and we show here that this magma body has been active over the last 30 kyr. However, in addition to this axial magma reservoir, we highlight in this paper the importance of a second, distinct magma reservoir, located 15 km west of the current axis, which has been the principal focus of magma accumulation from 15 ka to the subrecent. Magma supply to the axial reservoir substantially decreased between 20 ka and the present day, while the flank reservoir appears to have been regularly supplied with magma since 15 ka ago, resulting in less variably differentiated lavas. The trace element characteristics of magmas from both reservoirs were generated by variable degrees of partial melting of a single homogeneous mantle source, but their respective magmas evolved separately in distinct crustal plumbing systems. Magmatism in the Dabbahu/Manda Hararo rift segment is not focussed within the current axial depression but instead is spread out over at least 15 km on the western flank. This is consistent with magneto-telluric observations which show that two magma bodies are present below the segment, with the main accumulation of magma currently located below the western flank, precisely where the most voluminous recent (<15 ka) flank volcanism is observed at the surface. Applying these observations to slow spreading mid-ocean ridges indicates that magma bodies likely have a lifetime of a least 20 ka, and that the continuity of magmatic activity is

  1. Change in Mediterranean Hydrologic Cycle at Time of Heinrich Events From a High Resolution Multiproxy Record of the Last 50 kyr

    NASA Astrophysics Data System (ADS)

    Bout-Roumazeilles, V.; Combourieu Nebout, N.; Peyron, O.; Dormoy, I.

    2008-12-01

    Clay mineralogy, pollen record and pollen-based reconstructions were performed over the last climatic cycle on the Site ODP 976 (Alboran Sea, Western Mediterranean). These proxies show that several droughts occurred during the past 50 kyr. Enhanced contribution of wind-blown palygorskite and development of the semi-arid vegetation (Artemisia rich) occurs during the North Atlantic Cold climatic events (Heinrich events). The peculiar clay mineral association and the presence of Argania pollen grains pinpoint Western Morocco as a major source for wind-blown particles during the Heinrich events. Clay mineral and pollen associations indicate the development of semi-desert environment and the intensification of winds favoring dust erosion and transport from Sahara toward the Alboran Sea during the North Atlantic Heinrich events. Quantitative climate reconstructions performed on the ODP976 pollen record have yielded the reconstruction of ombrothermic diagrams for past key periods. They reveal that annual precipitations regime in the west Mediterranean area were rather different during Heinrich events than today with drastic drought during the whole year. As a comparison, the reconstructed Holocene and stadials annual climatic cycles are very similar to present-day distribution, with dry conditions restricted to summertime. During these cold climatic events, the drastic fall in both precipitations and temperatures suggest cold and arid continental conditions in the West Mediterranean area. These regions were suffering from reduced precipitations not only during winter but also during spring and fall usually experiencing wet conditions. Such a major modification, with repetitive cold and dry-conditions in both winter and spring, should have deeply affected the development of temperate forest -sensitive to precipitation amount- and of the Mediterranean forest which lives under warm-dry summer and mild-humid winter conditions. These clay- and pollen-based reconstructions

  2. The Emsian - Eifelian (Lower - Middle Devonian) boundary occurs in a 100-kyr eccentricity maximum: A potentially useful secondary marker for the GSSP section (Wetteldorf Richtschnitt, Germany).

    NASA Astrophysics Data System (ADS)

    De Vleeschouwer, D.; Makarona, C.; Linnemann, U.; Königshof, P.; Claeys, P. F.

    2015-12-01

    . We observe a mixed forcing of obliquity and eccentricity-modulated precession. Moreover, the Emsian - Eifelian boundary clearly occurs shortly after a 100-kyr eccentricity maximum. This cyclostratigraphic observation can be used as an additional mean in future long-distance correlations between Emsian - Eifelian boundary sections.

  3. Late Quaternary evolution of Lago Castor (Chile, 45.6°S): Timing of the deglaciation in northern Patagonia and evolution of the southern westerlies during the last 17 kyr

    NASA Astrophysics Data System (ADS)

    Van Daele, Maarten; Bertrand, Sébastien; Meyer, Inka; Moernaut, Jasper; Vandoorne, Willem; Siani, Giuseppe; Tanghe, Niels; Ghazoui, Zakaria; Pino, Mario; Urrutia, Roberto; De Batist, Marc

    2016-02-01

    Even though Patagonia is ideally located to study climate of the southern mid-latitudes, many questions on the late Quaternary climate evolution remain unresolved. The timing of maximum glacier extent is still uncertain in vast areas, and the postglacial evolution of the Southern Westerly Wind Belt (SWWB) remains highly debated. Here, we study the sedimentary infill of a glacigenic lake (Lago Castor; 45.6°S, 71.8°W) located at the leeside of the Andes in Chilean Patagonia to i) reconstruct the deglacial evolution of the eastern flank of the Patagonian Ice Sheet (PIS), and ii) discuss postglacial changes in wind strength at a critical location where westerly wind records are critically lacking. A dense grid of high-resolution reflection-seismic data was used to reconstruct the large-scale infill history of the lake, and a radiocarbon dated sediment core penetrating all lacustrine seismic units, was retrieved. Results indicate that the deglaciation of the lake basin and its catchment occurred no later than ∼28 cal kyr BP (i.e. an early LGM), but possibly even already after MIS 4. Afterwards, the Lago Castor area was covered by a large proglacial lake that drained - possibly through an outburst flood - when the PIS outlet glaciers retreated to a critical location. Subsequently, very dry conditions caused the lake to desiccate, as evidenced by an unconformity visible on the seismic profiles and in the sediment core. This dry period likely resulted from the increased orographic effect of the PIS-covered Andes, accompanied by weaker westerlies. From ∼20 kyr BP onwards, the combination of a shrinking PIS and a southward shift of the SWWB resulted in increased precipitation, which caused the lake level to rise. After ∼17 cal kyr BP, lake sedimentation was more directly influenced by the southern westerlies, with the formation of sediment drifts resulting from strong bottom current during periods of intense westerly winds. Our results suggest a progressive increase

  4. A revised configuration of the southern California uplift

    USGS Publications Warehouse

    Castle, R.O.; Gilmore, T.D.

    1992-01-01

    Recently recovered archival levelling data from southwestern Arizona and adjacent parts of California compel major revisions in the configuration and interpretation of the southern California uplift, both at its culmination and following its partial collapse. Re-examination of the older vertical-control record indicates that similar modifications may be equally appropriate in any reconsideration of the early-20th-century analogue of the southern California uplift. The chief changes in our earlier reconstructions appear as a sharply diminished isobase gradient south of Cottonwood Pass, dramatically reduced tectonic subsidence centering on the Salton Sea, and short-lived uplift of of at least 0.3 m at the latitude of El Centro. A newly refined qualitative interpretation of the data implies contraction and decoupling at the base of the seismogenic zone, in conjunction with right-stepping movement and extension between an en echelon transform pair through the Salton Basin. -from Authors

  5. Clean Air Act. Revision 5

    SciTech Connect

    Not Available

    1994-02-15

    This Reference Book contains a current copy of the Clean Air Act, as amended, and those regulations that implement the statute and appear to be most relevant to DOE activities. The document is provided to DOE and contractor staff for informational purposes only and should not be interpreted as legal guidance. This Reference Book has been completely revised and is current through February 15, 1994.

  6. Revision IPAA: strategies for success.

    PubMed

    Larson, David W

    2014-07-01

    The history of ileal pouch-anal anastomosis (IPAA) is one of success with durable surgical and functional results. However, pouch failure, due to infection, mechanical, or functional disability, represents a challenge to both surgeon and patient. Practicing surgeons who deal with the revision pouch face a variety of challenges. Success requires a strategy, which includes critical planning, preparation, and surgical techniques in order that surgeons continue to provide solutions and hope to patients.

  7. Clinical significance of osteoblast precursors and osteoclast precursors in earlier diagnosis and monitoring of myeloma bone disease.

    PubMed

    Fu, Rong; Peng, Fengping; Liu, Hui; Wang, Yihao; Li, Lijuan; Wang, Guojin; Song, Jia; Shao, Zonghong

    2016-06-01

    Bone disease is the most common complication of multiple myeloma (MM). In order to diagnose and monitor the bone damages earlier, we detected circulating osteoclast precursors (OCPs) and osteoblast precursors (OBPs) by flow cytometry, comparing with special biochemical markers, such as tartrate-resistant acid phosphatase isoform 5b (TRACP-5b), carboxy-terminal cross-linking telopeptide of type I collagen (CTX), osteocalcin (OCN), and procollagen I amino-terminal propeptide (PINP). The results showed that the circulating OBPs in the newly diagnosed MM patients significantly decreased compared with the normal controls (7.14 vs 12.82 %, P = 0.045), while circulating OCPs in the newly diagnosed patients and remission patients were significantly increased than the normal controls (2.46 vs 0.17 %, P = 0.000; 1.87 vs 0.17 %, P = 0.000, respectively). According to X-ray, newly diagnosed patients were divided into stages A and B (without and with osteolytic lesions). Compared with the normal controls, the circulating OBPs in stages A and B reduced (12.82 vs 7.47 %, P = 0.041; 12.82 vs 7.14 %, P = 0.010, respectively), while the circulating OCPs elevated (0.17 vs 2.31 %, P=0.010; 0.17 % vs 2.71 %, P=0.001, respectively). The levels of TRACP-5b and CTX in the newly diagnosed patients were higher than the normal controls (P = 0.014, P = 0.037) and remission patients (P = 0.025, P = 0.003), and they were significantly higher in stage B than the normal controls (P = 0.015, P = 0.002). However, the PINP and OCN levels had no significant changes in different stages. In conclusion, abnormal circulating OBPs and OCPs were found earlier before X-ray in MM and still existed in remission patients, indicating that they may be novel predictive markers for early diagnosing and monitoring bone disease.

  8. Deeper and earlier penetrations of oxygen ions than protons into the inner magnetosphere Observed by Van Allen probes.

    NASA Astrophysics Data System (ADS)

    Mitani, K.; Seki, K.; Keika, K.; Lanzerotti, L. J.; Gkioulidou, M.; Mitchell, D. G.; Kletzing, C.

    2015-12-01

    It is observationally known that proton and oxygen ions are main components of the ring current during magnetic storms and that the proton and oxygen ions are considered to have different source and supply mechanisms. However, detailed properties of the ion supply and their dependence on ion species is far from well understood. To characterize the ion supply to the ring current during magnetic storms, we report studies of the properties of energetic proton and oxygen ion phase space densities (PSDs) during the April 23-25, 2013, geomagnetic storm observed by the Van Allen Probes mission. We used energetic ion (~50 - ~600keV protons, ~140 - ~1100keV oxygen) and magnetic field data obtained by the RBSPICE and EMFISIS, respectively, on the Van Allen Probes. We calculated ion PSDs for the specific first adiabatic invariant, mu (0.3 < mu < 12 keV/nT), and ion pitch angles near 90 degrees as a function of L for each spacecraft orbit. The results show that both proton and oxygen ions penetrated directly to L<5 during the main phase of the magnetic storm. Protons with smaller mu values (mu = 0.3 and 0.5 keV/nT) penetrated earlier than those with larger mu values (mu = 1.0 keV/nT). This result appears consistent with the energy dependence of the Alfven layer. The timing of oxygen ion penetration is approximately the same for all mu values (mu = 0.8, 1.0 and 1.2 keV/nT). The observations also show that oxygen ions penetrated more deeply in L and earlier in time than protons for the same mu value (mu = 1.0keV/nT). These results suggest that the source of the transported oxygen ions is located closer to the Earth than the inner edge of protons. The results imply the importance of the contribution from subauroral oxygen ions to the storm-time ring current. We will also discuss the possibility of non-adiabatic acceleration of oxygen ions in the inner magnetosphere.

  9. Genetic Contribution to the Development of Radiographic Knee Osteoarthritis in a Population Presenting with Nonacute Knee Symptoms a Decade Earlier

    PubMed Central

    Huétink, Kasper; van der Voort, Paul; Bloem, Johan L.; Nelissen, Rob G. H. H.; Meulenbelt, Ingrid

    2016-01-01

    This study examined the contribution of the osteoarthritis (OA) susceptibility genes ASPN, GDF5, DIO2, and the 7q22 region to the development of radiographic knee OA in patients with a mean age of 40.6 ± 7.9 years (standard deviation) and who suffered from nonacute knee complaints a decade earlier. Dose–response associations of four single nucleotide polymorphisms(SNPs) in the susceptibility genes were determined by comparing 36 patients who showed the development of OA on radiographs (Kellgren and Lawrence score ≥1) with 88 patients having normal cartilage with no development of OA on radiographs. Multivariate logistic regression analysis including the variables such as age, gender, body mass index, and reported knee trauma was performed. A dose–response association of DIO2 SNP rs225014: odds ratio (OR) 2.3, 95% confidence interval (CI) 1.1–4.5 (P = 0.019) and GDF5 SNP rs143383: OR 2.0, 95% CI 1.1–3.8 (P = 0.031) was observed with knee OA development. The ASPN and 7q22 SNPs were not associated with OA development. PMID:27158223

  10. Earlier application of percutaneous cardiopulmonary support rescues patients from severe cardiopulmonary failure using the APACHE III scoring system.

    PubMed

    Song, Suk-Won; Yang, Hong-Suk; Lee, Sak; Youn, Young-Nam; Yoo, Kyung-Jong

    2009-12-01

    Percutaneous cardiopulmonary support (PCPS) is a widely accepted treatment for severe cardiopulmonary failure. This system, which uses a percutaneous approach and autopriming devices, can be rapidly applied in emergency situations. We sought to identify the risk factors that could help predict in-hospital mortality, and to assess its outcomes in survivors. During a 2-yr period, 50 patients underwent PCPS for the treatment of severe cardiopulmonary failure, and of those, 22 (44%) were classified as survivors and 28 (56%) as non-survivors. We compared the 2 groups for risk factors of in-hospital mortality and to establish proper PCPS timing. Twenty patients underwent PCPS for acute myocardial infarction, 20 for severe cardiopulmonary failure after cardiac surgery, 7 for acute respiratory distress syndrome, and 3 for acute myocarditis. Multivariate analysis showed that an acute physiology, age, and chronic health evaluation (APACHE) III score >or=50 prior to PCPS was the only significant predictor of in-hospital mortality (P=0.001). Overall 18-month survival was 42.2%. Cox analysis showed patients with APACHE III scores >or=50 had a poor prognosis (P=0.001). Earlier application of PCPS, and other preemptive strategies designed to optimize high-risk patients, may improve patient outcomes. Identifying patients with high APACHE scores at the beginning of PCPS may predict in-hospital mortality. Survivors, particularly those with higher APACHE scores, may require more frequent follow-up to improve overall survival.

  11. Comparison of explosive force between young and elderly women: evidence of an earlier decline from explosive force.

    PubMed

    Schettino, Ludmila; Luz, Carla Patrícia Novais; de Oliveira, Leandra Eugênia Gomes; de Assunção, Paula Lisiane; da Silva Coqueiro, Raildo; Fernandes, Marcos Henrique; Brown, Lee E; Machado, Marco; Pereira, Rafael

    2014-04-01

    The aging process causes many changes in muscle strength, and analysis of explosive force from handgrip strength seems to be useful and promising in studying the aging musculoskeletal system. Therefore, the purpose of this study was to investigate if explosive force parameters [rate of force development (RFD) and contractile impulse (CI) over the time interval of 0-200 ms from the onset of contraction] during handgrip efforts decline differently than maximum handgrip strength with increasing age. Twenty healthy young women (20-27 years) and 65 healthy elderly women, assigned into three age groups (50-64, 65-74, and 75-86 years), participated in this study. All participants performed two maximal grip attempts. Handgrip data were recorded as force-time curves, peak force, and explosive force parameters. Our results revealed that peak force decreased significantly (p < 0.05) for those who are 65 years old, while explosive force parameters decreased significantly (p < 0.05) for those aged 50 years. These data indicate that the decline in explosive grip force-generating capacity may begin earlier (i.e., for those aged 50 years old) than peak force during the aging process. Our findings suggest that the aging process reduces the explosive grip force-generating capacity before affecting peak force.

  12. Intravenous paracetamol infusion: Superior pain management and earlier discharge from hospital in patients undergoing palliative head-neck cancer surgery

    PubMed Central

    Majumdar, Saikat; Das, Anjan; Kundu, Ratul; Mukherjee, Dipankar; Hazra, Bimal; Mitra, Tapobrata

    2014-01-01

    Background: Paracetamol; a cyclooxygenase inhibitor; acts through the central nervous system as well as serotoninergic system as a nonopioid analgesic. A prospective, double-blinded, and randomized-controlled study was carried out to compare the efficacy of preoperative 1g intravenous (iv) paracetamol with placebo in providing postoperative analgesia in head-neck cancer surgery. Materials and Methods: From 2008 February to 2009 December, 80 patients for palliative head-neck cancer surgery were randomly divided into (F) and (P) Group receiving ivplacebo and iv paracetamol, respectively, 5 min before induction. Everybody received fentanyl before induction and IM diclofenac for pain relief at8 hourly for 24 h after surgery. Visual analogue scale (VAS) and amount of fentanyl were measured for postoperative pain assessment (24 h). Results and Statistical analysis: The mean VAS score in 1st, 2nd postoperative hour, and fentanyl requirement was less and the need for rescue analgesic was delayed in ivparacetamol group which were all statistically significant. Paracetamol group had a shorter surgical intensive care unit (SICU) and hospital stay which was also statistically significant. Conclusion: The study demonstrates the effectiveness of ivparacetamol as preemptive analgesic in the postoperative pain control after head-neck cancer surgery and earlier discharge from hospital. PMID:25276627

  13. The two faces of selective memory retrieval: Earlier decline of the beneficial than the detrimental effect with older age.

    PubMed

    Aslan, Alp; Schlichting, Andreas; John, Thomas; Bäuml, Karl-Heinz T

    2015-12-01

    Recent work with young adults has shown that, depending on study context access, selective memory retrieval can both impair and improve recall of other memories (Bäuml & Samenieh, 2010). Here, we investigated the 2 opposing effects of selective retrieval in older age. In Experiment 1, we examined 64 younger (20-35 years) and 64 older participants (above 60 years), and manipulated study context access using list-method directed forgetting. Whereas both age groups showed a detrimental effect of selective retrieval on to-be-remembered items, only younger but not older adults showed a beneficial effect on to-be-forgotten items. In Experiment 2, we examined 112 participants from a relatively wide age range (40-85 years), and manipulated study context access by varying the retention interval between study and test. Overall, a detrimental effect of selective retrieval arose when the retention interval was relatively short, but a beneficial effect when the retention interval was prolonged. Critically, the size of the beneficial but not the detrimental effect of retrieval decreased with age and this age-related decline was mediated by individuals' working memory capacity, as measured by the complex operation span task. Together, the results suggest an age-related dissociation in retrieval dynamics, indicating an earlier decline of the beneficial than the detrimental effect of selective retrieval with older age. PMID:26652723

  14. A test of the intergenerational conflict model in Indonesia shows no evidence of earlier menopause in female-dispersing groups

    PubMed Central

    Snopkowski, Kristin; Moya, Cristina; Sear, Rebecca

    2014-01-01

    Menopause remains an evolutionary puzzle, as humans are unique among primates in having a long post-fertile lifespan. One model proposes that intergenerational conflict in patrilocal populations favours female reproductive cessation. This model predicts that women should experience menopause earlier in groups with an evolutionary history of patrilocality compared with matrilocal groups. Using data from the Indonesia Family Life Survey, we test this model at multiple timescales: deep historical time, comparing age at menopause in ancestrally patrilocal Chinese Indonesians with ancestrally matrilocal Austronesian Indonesians; more recent historical time, comparing age at menopause in ethnic groups with differing postmarital residence within Indonesia and finally, analysing age at menopause at an individual-level, assuming a woman facultatively adjusts her age at menopause based on her postmarital residence. We find a significant effect only at the intermediate timescale where, contrary to predictions, ethnic groups with a history of multilocal postnuptial residence (where couples choose where to live) have the slowest progression to menopause, whereas matrilocal and patrilocal ethnic groups have similar progression rates. Multilocal residence may reduce intergenerational conflicts between women, thus influencing reproductive behaviour, but our results provide no support for the female-dispersal model of intergenerational conflict as an explanation of menopause. PMID:24966311

  15. A test of the intergenerational conflict model in Indonesia shows no evidence of earlier menopause in female-dispersing groups.

    PubMed

    Snopkowski, Kristin; Moya, Cristina; Sear, Rebecca

    2014-08-01

    Menopause remains an evolutionary puzzle, as humans are unique among primates in having a long post-fertile lifespan. One model proposes that intergenerational conflict in patrilocal populations favours female reproductive cessation. This model predicts that women should experience menopause earlier in groups with an evolutionary history of patrilocality compared with matrilocal groups. Using data from the Indonesia Family Life Survey, we test this model at multiple timescales: deep historical time, comparing age at menopause in ancestrally patrilocal Chinese Indonesians with ancestrally matrilocal Austronesian Indonesians; more recent historical time, comparing age at menopause in ethnic groups with differing postmarital residence within Indonesia and finally, analysing age at menopause at an individual-level, assuming a woman facultatively adjusts her age at menopause based on her postmarital residence. We find a significant effect only at the intermediate timescale where, contrary to predictions, ethnic groups with a history of multilocal postnuptial residence (where couples choose where to live) have the slowest progression to menopause, whereas matrilocal and patrilocal ethnic groups have similar progression rates. Multilocal residence may reduce intergenerational conflicts between women, thus influencing reproductive behaviour, but our results provide no support for the female-dispersal model of intergenerational conflict as an explanation of menopause.

  16. Geochemical multielement signatures of glacial and interglacial facies of the Okhotsk Sea deepwater sediments during the past 350 kyr: A response to global climate changes at the orbital and millennial scales

    NASA Astrophysics Data System (ADS)

    Chebykin, Eugene P.; Gorbarenko, Sergey A.; Stepanova, Ol'ga G.; Panov, Vsevolod S.; Goldberg, Evgeny L.

    2015-03-01

    The previously dated deepwater sediment core MR06-04 PC-7R (length 1723 cm; 350 kyr) recovered from the central Okhotsk Sea (OS) was analyzed for biogenic compounds and for 63 chemical elements (using the inductively coupled plasma-mass spectrometry method) with a high resolution (1 cm; ~200 years). A one box model with two main members" and mathematical methods (based on multielemental composition of sediments) for the calculation of weight fractions (at each time slice) of two main types of geochemical facies that dominate during considerably diverse climatic periods (glacial maxima and interglacial optima) were proposed and tested. This model can be applied to other analogous natural systems whose sedimentation is driven by two main types of geochemical facies. The application of the developed model to the studied core revealed that variations of weight fractions of the typical interglacial and glacial geochemical facies in the sediments along the core depth (named as warm and cold "covariators," respectively) change synchronously with global and regional climate variability. Profiles of warm and inversed cold covariators coincide tightly, and their values increase during warm marine isotope stages and substages and decrease during cold ones over the last 350 kyr. Millennial scale changes in covariators had occurred simultaneously with abrupt variability in the OS productivity and sediment lithology and with millennial global climate variability. Some discrepancies in the warm and inversed cold covariators calculated using specific mathematical treatments revealed the episodic influence of volcanogenic matter presented in the core by visible tephra layers and cryptotephras.

  17. Adult bacterial meningitis-a quality registry study: earlier treatment and favourable outcome if initial management by infectious diseases physicians.

    PubMed

    Grindborg, Ö; Naucler, P; Sjölin, J; Glimåker, M

    2015-06-01

    Acute bacterial meningitis (ABM) is challenging for the admitting physician because it is a rare but fulminant disease, usually presenting without typical symptoms, and rapid treatment is pivotal. The purpose of this study was to evaluate the effect of initial management by infectious diseases (ID) physicians vs. non-ID physicians. A total of 520 consecutive adults (>17 years old), 110 with initial ID management and 410 with non-ID management, registered in the Swedish quality registry for community-acquired ABM January 2008 to December 2013, were analysed retrospectively. Primary outcome was appropriate treatment with antibiotics and corticosteroids <1 hour from admission. Secondary analyses were mortality during hospital stay and persisting neurological and hearing deficits at follow-up after 2 to 6 months. Differences in diagnostic treatment sequences also were analysed. Appropriate treatment <1 hour from admission was achieved significantly more often (41%) by ID physicians vs. non-ID physicians (24%) with an odds ratio (OR) of 2.4 (95% confidence interval [CI]: 1.40 to 4.14; p < 0.01) adjusted for confounders. The door-to-antibiotic time was significantly shorter, and significantly more patients were administered corticosteroids together with the first doses of antibiotics in the ID group. A trend of decreased mortality (4.5% vs. 8.0%) and sequelae at follow-up (24% vs. 44%; adjusted OR 0.55: 95% CI 0.31 to 1.00; p 0.05) were observed in the ID group vs. the non-ID group. Antibiotics were started without prior neuroimaging more often in the ID group (86% vs. 57%; p < 0.001). Initial management at the emergency department by ID physicians is associated with earlier appropriate treatment, more appropriate diagnostic treatment sequences and favourable outcome.

  18. Health Disparities in Mid-to-Late Life: The Role of Earlier Life Family and Neighborhood Socioeconomic Conditions

    PubMed Central

    Johnson, Rucker C.; Schoeni, Robert F.; Rogowski, Jeannette A.

    2012-01-01

    The relationship between neighborhoods of residence in young adulthood and health in mid to late life in the United States are examined using the 1968-2005 waves of the Panel Study of Income Dynamics (PSID). The sample consists of persons who were aged 20-30 in 1968 and are followed for a period of 38 years (N=2,730). Four-level hierarchical random effects models of self-assessed general health status as a function of individual, family, and neighborhood factors are estimated. Using the original sampling design of the PSID, we analyze adult health trajectories of married couples and neighbors followed from young adulthood through elderly ages to assess the magnitudes of the possible causal effects of family and neighborhood characteristics in young adulthood on health in mid to late life. Estimates suggest disparities in neighborhood conditions in young adulthood account for one-quarter of the variation in mid-to-late-life health. Living in poor neighborhoods during young adulthood is strongly associated with negative health outcomes in later life. This result is robust even in the presence of a reasonably large amount of potential unobservable individual and family factors that may significantly affect both neighborhood of residence and subsequent health status. Racial differences in health status in mid to late life are also associated with family and neighborhood socioeconomic conditions earlier in life. Three quarters of the black-white gap in health status at ages over 55 can be accounted for by differences in childhood socioeconomic status and neighborhood and family factors in young adulthood. PMID:22212443

  19. Progressively implementation of the new degrees at E.T.S. of Agriculture Engineering and extinction of the earlier degrees

    NASA Astrophysics Data System (ADS)

    Arce, A.; Caniego, J.; Vazquez, J.; Serrano, A.; Tarquis, A. M.; Cartagena, M. C.

    2012-04-01

    The Bologna process is to improve the quality of education, mobility, diversity and the competitiveness and involves three fundamental changes: transform of the structure of titles, changing in methods of teaching and implementation of the systems of quality assurance. Once that the new degrees have been implemented with this structure, and began at E.T.S. of Agriculture Engineering (ETSIA) at Madrid from 2010-2011 course, the main aim of this work is to deeply study the changes in teaching methodology as well as progressively implementation of the educational planning of the three new degrees: Engineering and Agronomic Graduate, Food Industry Engineering Graduate and Agro-environmental Graduate. Each one of them presents 240 ECTS with a common first course and will have access to an official Master in Agronomic Engineering. As part as an educational innovation project awarded by the Technical University of Madrid (UPM) to improve educational quality, the second course has been designed with the main objective to continue the educative model implemented last course. This model identifies several teaching activities and represents a proper teaching style at ETSIA-UPM. At the same time, a monitoring and development coordination plans have been established. On the other hand, a procedure to extinguish the earlier plans of Agriculture Engineering was also defined. Other activities related to this Project were the information improvement of the grades, in particular at High Schools centers, improving the processes of reception, counseling and tutoring and mentoring. Likewise, cooperative working workshops and programs to support the teaching of English language were implemented. Satisfaction surveys and opinion polls were done to professors and students involved in first course in order to test several aspects of this project. The students surveys were analyzed taking in account the academic results and their participation in mentoring activities giving a highly

  20. Health disparities in mid-to-late life: the role of earlier life family and neighborhood socioeconomic conditions.

    PubMed

    Johnson, Rucker C; Schoeni, Robert F; Rogowski, Jeannette A

    2012-02-01

    The relationship between neighborhoods of residence in young adulthood and health in mid-to-late life in the United States are examined using the 1968-2005 waves of the Panel Study of Income Dynamics (PSID). The sample consists of persons who were aged 20-30 in 1968 and are followed for a period of 38 years (N=2730). Four-level hierarchical random effects models of self-assessed general health status as a function of individual, family, and neighborhood factors are estimated. Using the original sampling design of the PSID, we analyze adult health trajectories of married couples and neighbors followed from young adulthood through elderly ages to assess the magnitudes of the possible causal effects of family and neighborhood characteristics in young adulthood on health in mid-to-late life. Estimates suggest disparities in neighborhood conditions in young adulthood account for one-quarter of the variation in mid-to-late life health. Living in poor neighborhoods during young adulthood is strongly associated with negative health outcomes in later-life. This result is robust even in the presence of a reasonably large amount of potential unobservable individual and family factors that may significantly affect both neighborhood of residence and subsequent health status. Racial differences in health status in mid-to-late life are also associated with family and neighborhood socioeconomic conditions earlier in life. Three quarters of the black-white gap in health status at ages over 55 can be accounted for by differences in childhood socioeconomic status and neighborhood and family factors in young adulthood.

  1. Radiofrequency ablation-increased CXCL10 is associated with earlier recurrence of hepatocellular carcinoma by promoting stemness.

    PubMed

    Ouyang, Yabo; Liu, Kai; Hao, Meijun; Zheng, Rongling; Zhang, Chunmiao; Wu, Yanning; Zhang, Xiaofeng; Li, Ning; Zheng, Jiasheng; Chen, Dexi

    2016-03-01

    Radiofrequency ablation (RFA) represents a valuable choice in hepatocellular carcinoma (HCC); however, local recurrence of HCC is common after RFA. Here, 20 primary HCC patients treated by RFA were enrolled. Before (termed 0d) and after RFA treatment for 1 and 7 days (termed 1d and 7d, respectively), plasma and noncancerous tissue were collected. ELISA assay showed that plasma C-X-C motif chemokine 10 (CXCL10) was increased in ten patients (type I patients) but decreased in the other 10 patients (type II patients). The mean interval for HCC recurrence in type I patients was less than the mean interval in type II patients. Interestingly, a significant negative correlation between interval for HCC recurrence and fold change of plasma CXCL10 (1d/0d or 7d/0d) was identified, suggesting that RFA-induced CXCL10 is associated with earlier HCC recurrence. Immunofluorescence assay showed that the receptor of CXCL10, chemokine (C-X-C motif) receptor 3 (CXCR3), was significantly increased in type I, but not type II, patients after RFA. In vitro assay demonstrated that CXCL10 stimulus increased the rate of CD133(+) cancer stem cells (CSCs) in HepG2 cells by binding to CXCR3 and then inducing c-Myc expression. Many studies have reported that induction of CD133(+) CSCs contributes to HCC recurrence. Thus, CXCL10-increased CD133(+) CSCs by activating CXCR3/c-Myc pathway might accelerate HCC recurrence after RFA. These data might have potential implications for HCC therapy.

  2. Revision and product generation software

    USGS Publications Warehouse

    ,

    1997-01-01

    The U.S. Geological Survey (USGS) developed revision and product generation (RevPG) software for updating digital line graph (DLG) data and producing maps from such data. This software is based on ARC/INFO, a geographic information system from Environmental Systems Resource Institute (ESRI). RevPG consists of ARC/INFO Arc Macro Language (AML) programs, C routines, and interface menus that permit operators to collect vector data using aerial images, to symbolize the data on-screen, and to produce plots and color-separated files for use in printing maps.

  3. Revision and Product Generation Software

    USGS Publications Warehouse

    ,

    1999-01-01

    The U.S. Geological Survey (USGS) developed revision and product generation (RevPG) software for updating digital line graph (DLG) data and producing maps from such data. This software is based on ARC/INFO, a geographic information system from Environmental Systems Resource Institute (ESRI). RevPG consists of ARC/INFO Arc Macro Language (AML) programs, C routines, and interface menus that permit operators to collect vector data using aerial images, to symbolize the data onscreen, and to produce plots and color-separated files for use in printing maps.

  4. Earlier growing seasons and changes in migration timing influence carbon uptake and plant production in Arctic coastal wetlands

    NASA Astrophysics Data System (ADS)

    Leffler, A. J.; Beard, K. H.; Kelsey, K.; Choi, R. T.; Welker, J. M.

    2015-12-01

    The wetlands of the Yukon-Kuskokwim Delta in western Alaska are important breeding areas for geese and are experiencing rapid climate change, specifically earlier onset of the growing season. Consequently, geese arrive 'later' in the growing season than in the past, potentially setting up a phenological mismatch with consequences for their nutrition, plant growth, and C and N processes in the ecosystem. We examined the interactive effects between the start of the growing season and Black Brant arrival time on these processes in a manipulative experiment. Advancing the growing season had a modest influence on CO2 exchange and plant growth. An early growing season shifted the rate of net ecosystem exchange (NEE) by 1-1.5 µmol m-2 s-1 toward a carbon (C) source. This change was driven by an increase in the rate of ecosystem respiration (ER). The advanced growing season nearly doubled the rate of leaf elongation in the early summer and this difference persisted as taller vegetation later in the year; belowground biomass was not affected. Timing of grazing had greater influence on CO2 exchange and plant growth. Grazing early in the season shifted the system to a carbon source by ca. 2 μmol m-2 s-1 while delaying grazing enhanced the carbon sink by 1 μmol m-2 s-1. Here, the influence was not through ER, but through reducing and enhancing standing leaf area, respectively. Early grazing also reduced season-long root production by over 50% while delayed grazing enhanced root production by 30%. Although delaying grazing enhanced C uptake and promoted plant growth in this ecosystem, leaf tissue in delayed-grazing plots had C:N of 16.7 compared to 14.2 in the typical-grazing plots, potentially reducing the digestibility of goose forage and slowing rates of decomposition. Biotic forcing in arctic tundra can thus be major drivers of ecosystem function and need to be considered as tundra system respond to changing conditions.

  5. Brief Report: Enhanced Normalization of CD4/CD8 Ratio With Earlier Antiretroviral Therapy at Primary HIV Infection

    PubMed Central

    Inshaw, Jamie; Kaleebu, Pontiano; Cooper, David; Ramjee, Gita; Schechter, Mauro; Tambussi, Giuseppe; Fox, Julie; Samuel, Miriam; Miro, Jose M.; Weber, Jonathan; Porter, Kholoud; Fidler, Sarah

    2016-01-01

    Background: Total CD4+ T-cell counts predict HIV disease progression but do not necessarily reflect normalization of immune function. CD4/CD8 ratio is a marker of immune dysfunction, a prognostic indicator for non-AIDS mortality, and reflects viral reservoir size. Despite antiretroviral therapy (ART), recovery of CD4/CD8 ratio in chronic HIV infection is incomplete; we hypothesize enhanced CD4/CD8 ratio recovery with earlier treatment initiation in recently infected individuals. Methods: CD4+ count and CD4/CD8 ratio were analyzed using data from 2 cohorts: SPARTAC trial and the UK HIV Seroconverters Cohort where primary HIV infection (PHI) was defined as within 6 months from estimated date of infection. Using time-to-event methods and Cox proportional hazard models, we examined the effect of CD4/CD8 ratio at seroconversion on disease progression (CD4 <350 cells per cubic millimeter/ART initiation) and factors associated with time from ART initiation to CD4/CD8 normalization (ratio >1.0). Findings: Of 573 seroconverters, 482 (84%) had abnormal CD4/CD8 ratios at HIV seroconversion. Individuals with higher CD4/CD8 ratio at seroconversion were significantly less likely to reach the disease progression endpoint [adjusted hazard ratio (aHR) (95% CI) = 0.52 (0.32 to 0.82), P = 0.005]. The longer the interval between seroconversion and ART initiation [HR (95% CI) = 0.98 per month increase (0.97, 0.99), P < 0.001], the less likely the CD4/CD8 ratio normalization. ART initiation within 6 months from seroconversion was significantly more likely to normalize [HR (95% CI) = 2.47 (1.67 to 3.67), P < 0.001] than those initiating later. Interpretation: Most individuals presenting in PHI have abnormal CD4/CD8 ratios. The sooner the ART is initiated in PHI, the greater the probability of achieving normal CD4/CD8 ratio. PMID:27070122

  6. 42 CFR 405.1889 - Effect of a revision; issue-specific nature of appeals of revised determinations and decisions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 2 2014-10-01 2014-10-01 false Effect of a revision; issue-specific nature of appeals of revised determinations and decisions. 405.1889 Section 405.1889 Public Health CENTERS FOR... revision; issue-specific nature of appeals of revised determinations and decisions. (a) If a revision...

  7. 42 CFR 405.1889 - Effect of a revision; issue-specific nature of appeals of revised determinations and decisions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false Effect of a revision; issue-specific nature of appeals of revised determinations and decisions. 405.1889 Section 405.1889 Public Health CENTERS FOR... revision; issue-specific nature of appeals of revised determinations and decisions. (a) If a revision...

  8. 42 CFR 405.1889 - Effect of a revision; issue-specific nature of appeals of revised determinations and decisions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 2 2013-10-01 2013-10-01 false Effect of a revision; issue-specific nature of appeals of revised determinations and decisions. 405.1889 Section 405.1889 Public Health CENTERS FOR... revision; issue-specific nature of appeals of revised determinations and decisions. (a) If a revision...

  9. 42 CFR 405.1889 - Effect of a revision; issue-specific nature of appeals of revised determinations and decisions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 2 2012-10-01 2012-10-01 false Effect of a revision; issue-specific nature of appeals of revised determinations and decisions. 405.1889 Section 405.1889 Public Health CENTERS FOR... revision; issue-specific nature of appeals of revised determinations and decisions. (a) If a revision...

  10. Ocean Optics Protocols for Satellite Ocean Color Sensor Validation. Volume 6; Special Topics in Ocean Optics Protocols and Appendices; Revised

    NASA Technical Reports Server (NTRS)

    Mueller, J. L. (Editor); Fargion, Giulietta S. (Editor); McClain, Charles R. (Editor)

    2003-01-01

    This document stipulates protocols for measuring bio-optical and radiometric data for the Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) Project activities and algorithm development. The document is organized into 6 separate volumes as Ocean Optics Protocols for Satellite Ocean Color Sensor Validation, Revision 4. Volume I: Introduction, Background and Conventions; Volume II: Instrument Specifications, Characterization and Calibration; Volume III: Radiometric Measurements and Data Analysis Methods; Volume IV: Inherent Optical Properties: Instruments, Characterization, Field Measurements and Data Analysis Protocols; Volume V: Biogeochemical and Bio-Optical Measurements and Data Analysis Methods; Volume VI: Special Topics in Ocean Optics Protocols and Appendices. The earlier version of Ocean Optics Protocols for Satellite Ocean Color Sensor Validation, Revision 3 (Mueller and Fargion 2002, Volumes 1 and 2) is entirely superseded by the six volumes of Revision 4 listed above.

  11. 36 CFR 219.9 - Revision.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE PLANNING National Forest System Land and Resource Management Planning The Framework for Planning § 219.9 Revision. (a) Application..., new or revised Forest Service policies, relevant portions of the Forest Service national...

  12. 75 FR 60485 - NRC Enforcement Policy Revision

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-30

    ... On January 25, 2007 (72 FR 3429), the NRC published a notice announcing that the NRC was undertaking a major revision of its Enforcement Policy. On September 15, 2008 (73 FR 53286), the NRC published a... proposed revised Policy was published (73 FR 61442) on October 16, 2008. The public comment period for...

  13. Positive Culture Rate in Revision Shoulder Arthroplasty

    PubMed Central

    Hobgood, E. Rhett

    2009-01-01

    We recognized a trend of positive cultures taken from presumably uninfected shoulders during revision arthroplasty. Owing to the indolent nature of common shoulder pathogens such as Propionibacterium acnes, these cultures often become positive several days, even weeks, after surgery. Having concern regarding the potential importance of these positive cultures, we reviewed our revision arthroplasty population to determine the rate of positive intraoperative cultures in patients presumed to be aseptic, to characterize the isolated organisms, and to determine the subsequent development of infection. We retrospectively reviewed 27 patients (28 revisions) presumed to be uninfected between April 2005 and October 2007. Intraoperative cultures were positive in eight (29%) of the 28 revisions. Propionibacterium acnes was isolated in six. Methicillin-resistant Staphylococcus aureus was isolated in one patient and coagulase-negative Staphylococcus aureus was isolated in one patient. One-year followup was available on 24 of the 28 revisions. Two of the eight culture-positive revisions had a subsequent infection develop. Cultures taken at revision surgery for failed shoulder arthroplasty are often positive, and our findings document the importance of these positive cultures. Our data confirm previous reports isolating Propionibacterium acnes as a primary pathogen in revision shoulder arthroplasty. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:19434469

  14. 44 CFR 65.7 - Floodway revisions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... MAPPING OF SPECIAL HAZARD AREAS § 65.7 Floodway revisions. (a) General. Floodway data is developed as part... 44 Emergency Management and Assistance 1 2012-10-01 2011-10-01 true Floodway revisions. 65.7 Section 65.7 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT...

  15. 44 CFR 65.7 - Floodway revisions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MAPPING OF SPECIAL HAZARD AREAS § 65.7 Floodway revisions. (a) General. Floodway data is developed as part... 44 Emergency Management and Assistance 1 2011-10-01 2011-10-01 false Floodway revisions. 65.7 Section 65.7 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT...

  16. 44 CFR 65.7 - Floodway revisions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... MAPPING OF SPECIAL HAZARD AREAS § 65.7 Floodway revisions. (a) General. Floodway data is developed as part... 44 Emergency Management and Assistance 1 2013-10-01 2013-10-01 false Floodway revisions. 65.7 Section 65.7 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT...

  17. 44 CFR 65.7 - Floodway revisions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... MAPPING OF SPECIAL HAZARD AREAS § 65.7 Floodway revisions. (a) General. Floodway data is developed as part... 44 Emergency Management and Assistance 1 2014-10-01 2014-10-01 false Floodway revisions. 65.7 Section 65.7 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT...

  18. 50 CFR 37.25 - Revision.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC NATIONAL WILDLIFE REFUGE, ALASKA Exploration Plans § 37.25 Revision. (a) A permittee may request the Regional... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Revision. 37.25 Section 37.25 Wildlife...

  19. 50 CFR 37.25 - Revision.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC NATIONAL WILDLIFE REFUGE, ALASKA Exploration Plans § 37.25 Revision. (a) A permittee may request the Regional... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Revision. 37.25 Section 37.25 Wildlife...

  20. 50 CFR 37.25 - Revision.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC NATIONAL WILDLIFE REFUGE, ALASKA Exploration Plans § 37.25 Revision. (a) A permittee may request the Regional... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Revision. 37.25 Section 37.25 Wildlife...

  1. 50 CFR 37.25 - Revision.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC NATIONAL WILDLIFE REFUGE, ALASKA Exploration Plans § 37.25 Revision. (a) A permittee may request the Regional... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Revision. 37.25 Section 37.25 Wildlife...

  2. 50 CFR 37.25 - Revision.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC NATIONAL WILDLIFE REFUGE, ALASKA Exploration Plans § 37.25 Revision. (a) A permittee may request the Regional... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Revision. 37.25 Section 37.25 Wildlife...

  3. 40 CFR 51.326 - Reportable revisions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 2 2014-07-01 2014-07-01 false Reportable revisions. 51.326 Section 51.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS REQUIREMENTS... Action Reporting § 51.326 Reportable revisions. The State shall identify and describe all...

  4. 40 CFR 51.326 - Reportable revisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 2 2011-07-01 2011-07-01 false Reportable revisions. 51.326 Section 51.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS REQUIREMENTS... Action Reporting § 51.326 Reportable revisions. The State shall identify and describe all...

  5. 40 CFR 51.326 - Reportable revisions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Reportable revisions. 51.326 Section 51.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS REQUIREMENTS... Action Reporting § 51.326 Reportable revisions. The State shall identify and describe all...

  6. 40 CFR 51.326 - Reportable revisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Reportable revisions. 51.326 Section 51.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS REQUIREMENTS... Action Reporting § 51.326 Reportable revisions. The State shall identify and describe all...

  7. 40 CFR 51.326 - Reportable revisions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 2 2013-07-01 2013-07-01 false Reportable revisions. 51.326 Section 51.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS REQUIREMENTS... Action Reporting § 51.326 Reportable revisions. The State shall identify and describe all...

  8. How Mind Works To Revise Compositions.

    ERIC Educational Resources Information Center

    Lin, Deh-nan

    This study investigated cognitive processes involved in English-as-a-Second-Language (ESL) students' correcting and revising drafts after receiving oral feedback from their teachers, noting factors that led to better written products and factors that did not improve student writing. The study examined what kinds of revision strategies students…

  9. Revised State Budget Sells Kids Short

    ERIC Educational Resources Information Center

    Children Now, 2012

    2012-01-01

    The Administration's May Revision of the 2012-2013 state budget addresses a $15.7 billion shortfall through funding shifts, cuts, and new revenue sources that place children squarely in harms way. California's kids are already grossly underserved relative to the rest of the nation's children. If the May Revise budget is passed by the Legislature,…

  10. 25 CFR 276.14 - Budget revision.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Budget revision. 276.14 Section 276.14 Indians BUREAU OF... UNIFORM ADMINISTRATIVE REQUIREMENTS FOR GRANTS § 276.14 Budget revision. Criteria and procedures to be followed by grantees in reporting deviations from grant budgets and requesting approval for...

  11. 48 CFR 2801.270-1 - Revisions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Revisions. 2801.270-1 Section 2801.270-1 Federal Acquisition Regulations System DEPARTMENT OF JUSTICE General DEPARTMENT OF JUSTICE ACQUISITION REGULATIONS SYSTEM Administration 2801.270-1 Revisions. In addition to...

  12. 36 CFR 219.9 - Revision.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false Revision. 219.9 Section 219.9 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE PLANNING National Forest System Land and Resource Management Planning The Framework for Planning § 219.9 Revision. (a)...

  13. The Supervisor Emphasis Rating Form-Revised.

    ERIC Educational Resources Information Center

    Lanning, Wayne; Freeman, Brenda

    1994-01-01

    Discusses revision of Supervisor Emphasis Rating Form (SERF) into ipsative instrument and suggests future research that could profitably be done with new instrument. Explains rationale for choosing ipsative format and presents findings of study conducted to establish instrument reliability. SERF-Revised is appended. (Author/NB)

  14. Biogeochemical fingerprints of life: earlier analogies with polar ecosystems suggest feasible instrumentation for probing the Galilean moons

    NASA Astrophysics Data System (ADS)

    Chela-Flores, J.; Cicuttin, A.; Crespo, M. L.; Tuniz, C.

    2015-07-01

    We base our search for the right instrumentation for detecting biosignatures on Europa on the analogy suggested by the recent work on polar ecosystems in the Canadian Arctic at Ellesmere Island. In that location sulphur patches (analogous to the Europan patches) are accumulating on glacial ice lying over saline springs rich in sulphate and sulphide. Their work reinforces earlier analogies in Antarctic ecosystems that are appropriate models for possible habitats that will be explored by the European Space Agency JUpiter ICy Moons Explorer (JUICE) mission to the Jovian System. Its Jupiter Ganymede Orbiter (JGO) will include orbits around Europa and Ganymede. The Galileo orbital mission discovered surficial patches of non-ice elements on Europa that were widespread and, in some cases possibly endogenous. This suggests the possibility that the observed chemical elements in the exoatmosphere may be from the subsurface ocean. Spatial resolution calculations of Cassidy and co-workers are available, suggesting that the atmospheric S content can be mapped by a neutral mass spectrometer, now included among the selected JUICE instruments. In some cases, large S-fractionations are due to microbial reduction and disproportionation (although sometimes providing a test for ecosystem fingerprints, even though with Sim - Bosak - Ono we maintain that microbial sulphate reduction large sulphur isotope fractionation does not require disproportionation. We address the question of the possible role of oxygen in the Europan ocean. Instrument issues are discussed for measuring stable S-isotope fractionations up to the known limits in natural populations of δ34 ~ -70‰. We state the hypothesis of a Europa anaerobic oceanic population of sulphate reducers and disproportionators that would have the effect of fractionating the sulphate that reaches the low-albedo surficial regions. This hypothesis is compatible with the time-honoured expectation of Kaplan and co-workers (going back to the

  15. Climatic water deficit and wildfire: predicting spatial patterns in forest ecosystem sensitivity to warming and earlier spring snowmelt. (Invited)

    NASA Astrophysics Data System (ADS)

    Westerling, A. L.; Keyser, A.; Milostan, J.

    2013-12-01

    Western U.S. forest wildfire area burned increased significantly in recent decades, with much of the increase in the US Rocky Mountains (Westerling et al 2006). While Westerling et al (2006) noted that interannual variability in aggregate regional forest wildfire has been highly correlated with regional indices of warming and spring snowmelt, our analysis of the hydroclimatic conditions coincident with the occurrence of large forest wildfires in recent decades reveals that sensitivity of wildfire in specific forest areas has been characterized by a narrow range of climatic conditions: long-term average snow-free season of ~2-4 months and relatively high cumulative water-year actual evapotranspiration (AET). These forests have shown large increases in cumulative water year moisture deficit concomitant with large increases in wildfire in recent years with warmer than average temperatures and earlier spring snowmelt. Forests with high AET and snow-free seasons between 4 and 5 months have exhibited significant but more moderate increases in wildfire activity. Mean snow-free season length and cumulative AET may also be predictive of forest wildfire sensitivity to projected warming. Recent climate change impact studies indicate that the same forests where wildfire activity has exhibited the most sensitivity to observed warming in recent decades may continue to exhibit large increases in the next few decades, until reductions in fuel availability and continuity become dominant constraints on the growth of large wildfires (e.g., Westerling et al 2011a, Litschert et al 2012, Westerling et al unpublished data). We also find that similar forests that may have been buffered from recent climate change by elevation or latitude may also show very large increases in wildfire under projected warming. Conversely, warmer, drier forests where recent changes in moisture deficit and fire activity have been more moderate (particularly those with snow-free seasons ~4-5 months), are

  16. Climatic water deficit and wildfire: predicting spatial patterns in forest ecosystem sensitivity to warming and earlier spring snowmelt. (Invited)

    NASA Astrophysics Data System (ADS)

    Westerling, A. L.; Keyser, A.; Milostan, J.

    2011-12-01

    Western U.S. forest wildfire area burned increased significantly in recent decades, with much of the increase in the US Rocky Mountains (Westerling et al 2006). While Westerling et al (2006) noted that interannual variability in aggregate regional forest wildfire has been highly correlated with regional indices of warming and spring snowmelt, our analysis of the hydroclimatic conditions coincident with the occurrence of large forest wildfires in recent decades reveals that sensitivity of wildfire in specific forest areas has been characterized by a narrow range of climatic conditions: long-term average snow-free season of ~2-4 months and relatively high cumulative water-year actual evapotranspiration (AET). These forests have shown large increases in cumulative water year moisture deficit concomitant with large increases in wildfire in recent years with warmer than average temperatures and earlier spring snowmelt. Forests with high AET and snow-free seasons between 4 and 5 months have exhibited significant but more moderate increases in wildfire activity. Mean snow-free season length and cumulative AET may also be predictive of forest wildfire sensitivity to projected warming. Recent climate change impact studies indicate that the same forests where wildfire activity has exhibited the most sensitivity to observed warming in recent decades may continue to exhibit large increases in the next few decades, until reductions in fuel availability and continuity become dominant constraints on the growth of large wildfires (e.g., Westerling et al 2011a, Litschert et al 2012, Westerling et al unpublished data). We also find that similar forests that may have been buffered from recent climate change by elevation or latitude may also show very large increases in wildfire under projected warming. Conversely, warmer, drier forests where recent changes in moisture deficit and fire activity have been more moderate (particularly those with snow-free seasons ~4-5 months), are

  17. 77 FR 73454 - Revision of Information Collection; Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-10

    ... requirements; revise the Grant Application Narrative questions to clarify new concepts; Simplify language and... alignment between narrative sections and the performance measures work plans. The proposed revisions do...

  18. Radiological control manual. Revision 1

    SciTech Connect

    Kloepping, R.

    1996-05-01

    This Lawrence Berkeley National Laboratory Radiological Control Manual (LBNL RCM) has been prepared to provide guidance for site-specific additions, supplements and interpretation of the DOE Radiological Control Manual. The guidance provided in this manual is one methodology to implement the requirements given in Title 10 Code of Federal Regulations Part 835 (10 CFR 835) and the DOE Radiological Control Manual. Information given in this manual is also intended to provide demonstration of compliance to specific requirements in 10 CFR 835. The LBNL RCM (Publication 3113) and LBNL Health and Safety Manual Publication-3000 form the technical basis for the LBNL RPP and will be revised as necessary to ensure that current requirements from Rules and Orders are represented. The LBNL RCM will form the standard for excellence in the implementation of the LBNL RPP.

  19. Advanced seasonal reproductive development in a male urban bird is reflected in earlier plasma luteinizing hormone rise but not energetic status.

    PubMed

    Davies, Scott; Behbahaninia, Hirbod; Giraudeau, Mathieu; Meddle, Simone L; Waites, Kyle; Deviche, Pierre

    2015-12-01

    Urban animals inhabit an environment considerably different than do their non-urban conspecifics, and to persist urban animals must adjust to these novel environments. The timing of seasonal reproductive development (i.e., growth of gonads and secondary sex organs) is a fundamental determinant of the breeding period and is frequently advanced in urban bird populations. However, the underlying mechanism(s) by which birds adjust the timing of reproductive development to urban areas remain(s) largely unknown. Here, we compared the timing of vernal reproductive development in free-ranging urban and non-urban male Abert's Towhees, Melozone aberti, in Phoenix, Arizona, USA, and tested the non-mutually exclusive hypotheses that earlier reproductive development is due to improved energetic status and/or earlier increase in endocrine activity of the reproductive system. We found that urban birds initiated testicular development earlier than non-urban birds, but this disparity was not associated with differences in body condition, fat stores, or innate immune performance. These results provide no support for the hypothesis that energetic constraints are responsible for delayed reproductive development of non-urban relative to urban male Abert's Towhees. Urban birds did, however, increase their plasma luteinizing hormone, but not plasma testosterone, earlier than non-urban birds. These findings suggest that adjustment to urban areas by Abert's Towhees involves increases in the endocrine activity of the anterior pituitary gland and/or hypothalamus earlier than non-urban towhees.

  20. Scar Revision Surgery: The Patient's Perspective

    PubMed Central

    Allan, Anna Y; Butler, Daniel P; Cussons, Paul D

    2015-01-01

    Background Insufficient satisfaction outcome literature exists to assist consultations for scar revision surgery; such outcomes should reflect the patient's perspective. The aim of this study was to prospectively investigate scar revision patient satisfaction outcomes, according to specified patient-selection criteria. Methods Patients (250) were randomly selected for telephone contacting regarding scar revisions undertaken between 2007-2011. Visual analogue scores were obtained for scars pre- and post-revision surgery. Surgery selection criteria were; 'presence' of sufficient time for scar maturation prior to revision, technical issues during or wound complications from the initial procedure that contributed to poor scarring, and 'absence' of site-specific or patient factors that negatively influence outcomes. Patient demographics, scar pathogenesis (elective vs. trauma), underlying issue (functional/symptomatic vs. cosmetic) and revision surgery details were also collected with the added use of a real-time, hospital database. Results Telephone contacting was achieved for 211 patients (214 scar revisions). Satisfaction outcomes were '2% worse, 16% no change, and 82% better'; a distribution maintained between body sites and despite whether surgery was functional/symptomatic vs. cosmetic. Better outcomes were reported by patients who sustained traumatic scars vs. those who sustained scars by elective procedures (91.80% vs. 77.78%, P=0.016) and by females vs. males (85.52% vs. 75.36%, P<0.05), particularly in the elective group where males (36.17%) were more likely to report no change or worse outcomes versus females (16.04%) (P<0.01). Conclusions Successful scar revision outcomes may be achieved using careful patient selection. This study provides useful information for referring general practitioners, and patient-surgeon consultations, when planning scar revision. PMID:26618120

  1. The economic impact of revision otologic surgery.

    PubMed

    Nadimi, Sahar; Leonetti, John P; Pontikis, George

    2016-03-01

    Revision otologic surgery places a significant economic burden on patients and the healthcare system. We conducted a retrospective chart analysis to estimate the economic impact of revision canal-wall-down (CWD) mastoidectomy. We reviewed the medical records of all 189 adults who had undergone CWD mastoidectomy performed by the senior author between June 2006 and August 2011 at Loyola University Medical Center in Maywood, Ill. Institutional charges and collections for all patients were extrapolated to estimate the overall healthcare cost of revision surgery in Illinois and at the national level. Of the 189 CWD mastoidectomies, 89 were primary and 100 were revision procedures. The total charge for the revision cases was $2,783,700, and the net reimbursement (collections) was $846,289 (30.4%). Using Illinois Hospital Association data, we estimated that reimbursement for 387 revision CWD mastoidectomies that had been performed in fiscal year 2011 was nearly $3.3 million. By extrapolating our data to the national level, we estimated that 9,214 patients underwent revision CWD mastoidectomy in the United States during 2011, which cost the national healthcare system roughly $76 million, not including lost wages and productivity. Known causes of failed CWD mastoidectomies that often result in revision surgery include an inadequate meatoplasty, a facial ridge that is too high, residual diseased air cells, and recurrent cholesteatoma. A better understanding of these factors can reduce the need for revision surgery, which could have a positive impact on the economic strain related to this procedure at the local, state, and national levels. PMID:26991218

  2. Introductory Business Textbook Revision Cycles: Are They Getting Shorter?

    ERIC Educational Resources Information Center

    Zinser, Brian; Brunswick, Gary

    2010-01-01

    The rate of textbook revision cycles is examined in light of the recent trend towards more rapid revisions (and adoptions of textbooks). The authors conduct background research to better understand the context for textbook revision cycles and the environmental forces that have been influencing what appears to be more rapid textbook revisions. A…

  3. 40 CFR 142.12 - Revision of State programs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... § 142.12 Revision of State programs. (a) General requirements. Either EPA or the primacy State may initiate actions that require the State to revise its approved State primacy program. To retain primary... State revises its approved primacy program to adopt new or revised Federal regulations, the State...

  4. 40 CFR 142.12 - Revision of State programs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... § 142.12 Revision of State programs. (a) General requirements. Either EPA or the primacy State may initiate actions that require the State to revise its approved State primacy program. To retain primary... State revises its approved primacy program to adopt new or revised Federal regulations, the State...

  5. 40 CFR 142.12 - Revision of State programs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... § 142.12 Revision of State programs. (a) General requirements. Either EPA or the primacy State may initiate actions that require the State to revise its approved State primacy program. To retain primary... State revises its approved primacy program to adopt new or revised Federal regulations, the State...

  6. 40 CFR 142.12 - Revision of State programs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... § 142.12 Revision of State programs. (a) General requirements. Either EPA or the primacy State may initiate actions that require the State to revise its approved State primacy program. To retain primary... State revises its approved primacy program to adopt new or revised Federal regulations, the State...

  7. 40 CFR 142.12 - Revision of State programs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... § 142.12 Revision of State programs. (a) General requirements. Either EPA or the primacy State may initiate actions that require the State to revise its approved State primacy program. To retain primary... State revises its approved primacy program to adopt new or revised Federal regulations, the State...

  8. 40 CFR 255.41 - Procedure for revision.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... IDENTIFICATION OF REGIONS AND AGENCIES FOR SOLID WASTE MANAGEMENT Submission and Revision of Identifications... for solid waste functions in the region. (b) Revisions or adjustments to the State plan may require... notified of such revisions by the State solid waste agency. (c) Major revisions or adjustments in...

  9. 15 CFR 923.128 - Revisions to assessments and strategies.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... strategies. 923.128 Section 923.128 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign... Program § 923.128 Revisions to assessments and strategies. (a) A State, in consultation with the Assistant Administrator, may propose to revise its approved Strategy. Revision(s) to an approved Strategy must...

  10. A Comparative Study of Three Revision Methods in EFL Writing

    ERIC Educational Resources Information Center

    Srichanyachon, Napaporn

    2011-01-01

    In an attempt to explore effective instruction in the English as a Foreign Language (EFL) setting, this study investigated language errors identified by students and teachers in three different revision stages: self-revision, peer revision, and teacher revision. It gave the focus to the effects of the three different methods on learners' writing…

  11. Nevada Test Site Radiological Control Manual. Revision 1

    SciTech Connect

    None, None

    2010-02-09

    This document supersedes DOE/NV/25946--801, “Nevada Test Site Radiological Control Manual,” Revision 0 issued in October 2009. Brief Description of Revision: A minor revision to correct oversights made during revision to incorporate the 10 CFR 835 Update; and for use as a reference document for Tenant Organization Radiological Protection Programs.

  12. Real Revision: Authors' Strategies to Share with Student Writers

    ERIC Educational Resources Information Center

    Messner, Kate

    2011-01-01

    How do you show students that revision is more than a classroom exercise to please the teacher? Take them into the real world of writing for publication. In Real Revision, award-winning author and teacher Kate Messner demystifies the revision process for teachers and students alike and provides tried-and-true revision strategies, field tested by…

  13. Revised stratigraphy and chronology for Homo floresiensis at Liang Bua in Indonesia.

    PubMed

    Sutikna, Thomas; Tocheri, Matthew W; Morwood, Michael J; Saptomo, E Wahyu; Jatmiko; Awe, Rokus Due; Wasisto, Sri; Westaway, Kira E; Aubert, Maxime; Li, Bo; Zhao, Jian-xin; Storey, Michael; Alloway, Brent V; Morley, Mike W; Meijer, Hanneke J M; van den Bergh, Gerrit D; Grün, Rainer; Dosseto, Anthony; Brumm, Adam; Jungers, William L; Roberts, Richard G

    2016-04-21

    Homo floresiensis, a primitive hominin species discovered in Late Pleistocene sediments at Liang Bua (Flores, Indonesia), has generated wide interest and scientific debate. A major reason this taxon is controversial is because the H. floresiensis-bearing deposits, which include associated stone artefacts and remains of other extinct endemic fauna, were dated to between about 95 and 12 thousand calendar years (kyr) ago. These ages suggested that H. floresiensis survived until long after modern humans reached Australia by ~50 kyr ago. Here we report new stratigraphic and chronological evidence from Liang Bua that does not support the ages inferred previously for the H. floresiensis holotype (LB1), ~18 thousand calibrated radiocarbon years before present (kyr cal. BP), or the time of last appearance of this species (about 17 or 13-11 kyr cal. BP). Instead, the skeletal remains of H. floresiensis and the deposits containing them are dated to between about 100 and 60 kyr ago, whereas stone artefacts attributable to this species range from about 190 to 50 kyr in age. Whether H. floresiensis survived after 50 kyr ago--potentially encountering modern humans on Flores or other hominins dispersing through southeast Asia, such as Denisovans--is an open question.

  14. Revised stratigraphy and chronology for Homo floresiensis at Liang Bua in Indonesia.

    PubMed

    Sutikna, Thomas; Tocheri, Matthew W; Morwood, Michael J; Saptomo, E Wahyu; Jatmiko; Awe, Rokus Due; Wasisto, Sri; Westaway, Kira E; Aubert, Maxime; Li, Bo; Zhao, Jian-xin; Storey, Michael; Alloway, Brent V; Morley, Mike W; Meijer, Hanneke J M; van den Bergh, Gerrit D; Grün, Rainer; Dosseto, Anthony; Brumm, Adam; Jungers, William L; Roberts, Richard G

    2016-04-21

    Homo floresiensis, a primitive hominin species discovered in Late Pleistocene sediments at Liang Bua (Flores, Indonesia), has generated wide interest and scientific debate. A major reason this taxon is controversial is because the H. floresiensis-bearing deposits, which include associated stone artefacts and remains of other extinct endemic fauna, were dated to between about 95 and 12 thousand calendar years (kyr) ago. These ages suggested that H. floresiensis survived until long after modern humans reached Australia by ~50 kyr ago. Here we report new stratigraphic and chronological evidence from Liang Bua that does not support the ages inferred previously for the H. floresiensis holotype (LB1), ~18 thousand calibrated radiocarbon years before present (kyr cal. BP), or the time of last appearance of this species (about 17 or 13-11 kyr cal. BP). Instead, the skeletal remains of H. floresiensis and the deposits containing them are dated to between about 100 and 60 kyr ago, whereas stone artefacts attributable to this species range from about 190 to 50 kyr in age. Whether H. floresiensis survived after 50 kyr ago--potentially encountering modern humans on Flores or other hominins dispersing through southeast Asia, such as Denisovans--is an open question. PMID:27027286

  15. New and revised standards for coke production

    SciTech Connect

    G.A. Kotsyuba; M.I. Alpatov; Y.G. Shapoval

    2009-07-15

    The need for new and revised standards for coke production in Ukraine and Russia is outlined. Such standards should address improvements in plant operation, working conditions, environmental protection, energy conservation, fire and explosion safety, and economic indices.

  16. Facial Scar Revision: Understanding Facial Scar Treatment

    MedlinePlus

    ... Contact Us Trust your face to a facial plastic surgeon Facial Scar Revision Understanding Facial Scar Treatment ... face like the eyes or lips. A facial plastic surgeon has many options for treating and improving ...

  17. 78 FR 59982 - Revisions to Radiation Protection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-30

    ... From the Federal Register Online via the Government Publishing Office ] NUCLEAR REGULATORY COMMISSION Revisions to Radiation Protection AGENCY: Nuclear Regulatory Commission. ACTION: Standard review... Reports for Nuclear Power Plants: LWR Edition'': Section 12.1, ``Assuring that Occupational...

  18. Suggested revision for west mexican archeological sequences.

    PubMed

    Long, S V; Taylor, R E

    1966-12-16

    A review of the radiocarbon dates and published and unpublished archeological data from the West Mexican states of Sinaloa, Nayarit, Jalisco, and Colima has resulted in a revised tentative chronology for West Mexico.

  19. United States Nuclear Regulatory Commission staff practice and procedure digest. Commission, Appeal Board and Licensing Board decisions, July 1972-September 1985. Digest No. 4, Revision No. 1

    SciTech Connect

    Not Available

    1986-04-01

    This Revision 1 of the fourth edition of the NRC Staff Practice and Procedure Digest contains a digest of a number of Commission, Atomic Safety and Licensing Appeal Board, and Atomic Safety and Licensing Board decisions issued during the period from July 1, 1972 to September 30, 1985 interpreting the NRC's Rules of Practice in 10 CFR Part 2. This Revision 1 replaces earlier editions and supplements and includes appropriate changes reflecting the admendments to the Rules of Practice effective through September 20, 1985.

  20. Revision of failed humeral head resurfacing arthroplasty

    PubMed Central

    Streubel, Philipp N.; Simone, Juan P.; Cofield, Robert H.; Sperling, John W.

    2016-01-01

    Purpose: The purpose of this study is to assess the outcomes of a consecutive series of patients who underwent revision surgery after humeral head resurfacing (HHR). Our joint registry was queried for all patients who underwent revision arthroplasty for failed HHR at our institution from 2005 to 2010. Eleven consecutive patients (average age 54 years; range 38-69 years) that underwent revision of 11 resurfacing arthroplasties were identified. The primary indication for resurfacing had been osteoarthritis in six, glenoid dysplasia in two, a chondral lesion in two, and postinstability arthropathy in one patient. The indication for revision was pain in 10 and infection in one patient. Seven patients had undergone an average of 1.9 surgeries prior to resurfacing (range 1-3). Materials and Methods: All patients were revised to stemmed arthroplasties, including one hemiarthroplasty, two reverse, and eight anatomic total shoulder arthroplasties at a mean 33 months after primary resurfacing (range 10-131 months). A deltopectoral approach was used in seven patients; four patients required an anteromedial approach due to severe scarring. Subscapularis attenuation was found in four cases, two of which required reverse total shoulder arthroplasty. Bone grafting was required in one glenoid and three humeri. Results: At a mean follow-up of 3.5 years (range 1.6-6.9 years), modified Neer score was rated as satisfactory in five patients and unsatisfactory in six. Abduction and external rotation improved from 73° to 88° (P = 0.32) and from 23° to 32° (P = 0.28) respectively. Reoperation was required in two patients, including one hematoma and one revision for instability. Conclusion: Outcomes of revision of HHR arthroplasty in this cohort did not improve upon those reported for revision of stemmed humeral implants. A comparative study would be required to allow for definitive conclusions to be made. PMID:26980986

  1. HLW system plan - revision 2

    SciTech Connect

    Not Available

    1994-01-14

    The projected ability of the Tank Farm to support DWPF startup and continued operation has diminished somewhat since revision 1 of this Plan. The 13 month delay in DWPF startup, which actually helps the Tank Farm condition in the near term, was more than offset by the 9 month delay in ITP startup, the delay in the Evaporator startups and the reduction to Waste Removal funding. This Plan does, however, describe a viable operating strategy for the success of the HLW System and Mission, albeit with less contingency and operating flexibility than in the past. HLWM has focused resources from within the division on five near term programs: The three evaporator restarts, DWPF melter heatup and completion of the ITP outage. The 1H Evaporator was restarted 12/28/93 after a 9 month shutdown for an extensive Conduct of Operations upgrade. The 2F and 2H Evaporators are scheduled to restart 3/94 and 4/94, respectively. The RHLWE startup remains 11/17/97.

  2. 2011 Annual Survey of Journalism and Mass Communication Enrollments: Enrollments Decline, Reversing the Increase of a Year Earlier, and Suggesting Slow Growth for Future

    ERIC Educational Resources Information Center

    Becker, Lee B.; Vlad, Tudor; Kalpen, Konrad

    2012-01-01

    Enrollments in journalism and mass communication programs declined in the autumn of 2011, compared to a year earlier. Enrollments were down slightly at the senior and junior levels and substantially at the freshman level. Enrollment increased at the sophomore level. The majority of administrators say they have made curricular changes in the past…

  3. 42 CFR 405.1889 - Effect of a revision; issue-specific nature of appeals of revised determinations and decisions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Effect of a revision; issue-specific nature of... MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM FEDERAL HEALTH... revision; issue-specific nature of appeals of revised determinations and decisions. (a) If a revision...

  4. Revision of the DELFIC Particle Activity Module

    SciTech Connect

    Hooper, David A; Jodoin, Vincent J

    2010-09-01

    The Defense Land Fallout Interpretive Code (DELFIC) was originally released in 1968 as a tool for modeling fallout patterns and for predicting exposure rates. Despite the continual advancement of knowledge of fission yields, decay behavior of fission products, and biological dosimetry, the decay data and logic of DELFIC have remained mostly unchanged since inception. Additionally, previous code revisions caused a loss of conservation of radioactive nuclides. In this report, a new revision of the decay database and the Particle Activity Module is introduced and explained. The database upgrades discussed are replacement of the fission yields with ENDF/B-VII data as formatted in the Oak Ridge Isotope Generation (ORIGEN) code, revised decay constants, revised exposure rate multipliers, revised decay modes and branching ratios, and revised boiling point data. Included decay logic upgrades represent a correction of a flaw in the treatment of the fission yields, extension of the logic to include more complex decay modes, conservation of nuclides (including stable nuclides) at all times, and conversion of key variables to double precision for nuclide conservation. Finally, recommended future work is discussed with an emphasis on completion of the overall radiation physics upgrade, particularly for dosimetry, induced activity, decay of the actinides, and fractionation.

  5. Sequence stratigraphy and a revised sea-level curve for the Middle Devonian of eastern North America

    USGS Publications Warehouse

    Brett, Carlton E.; Baird, G.C.; Bartholomew, A.J.; DeSantis, M.K.; Ver Straeten, C.A.

    2011-01-01

    The well-exposed Middle Devonian rocks of the Appalachian foreland basin (Onondaga Formation; Hamilton Group, Tully Formation, and the Genesee Group of New York State) preserve one of the most detailed records of high-order sea-level oscillation cycles for this time period in the world. Detailed examination of coeval units in distal areas of the Appalachian Basin, as well as portions of the Michigan and Illinois basins, has revealed that the pattern of high-order sea-level oscillations documented in the New York-Pennsylvania section can be positively identified in all areas of eastern North America where coeval units are preserved. The persistence of the pattern of high-order sea-level cycles across such a wide geographic area suggests that these cycles are allocyclic in nature with primary control on deposition being eustatic sea-level oscillation, as opposed to autocylic controls, such as sediment supply, which would be more local in their manifestation. There is strong evidence from studies of cyclicity and spectral analysis that these cycles are also related to Milankovitch orbital variations, with the short and long-term eccentricity cycles (100. kyr and 405. kyr) being the dominant oscillations in many settings. Relative sea-level oscillations of tens of meters are likely and raise considerable issues about the driving mechanism, given that the Middle Devonian appears to record a greenhouse phase of Phanerozoic history. These new correlations lend strong support to a revised high-resolution sea-level oscillation curve for the Middle Devonian for the eastern portion of North America. Recognized third-order sequences are: Eif-1 lower Onondaga Formation, Eif-2: upper Onondaga and Union Springs formations; Eif-Giv: Oatka Creek Formation; Giv-1: Skaneateles, Giv-2: Ludlowville, Giv-3: lower Moscow, Giv-4: upper Moscow-lower Tully, and Giv-5: middle Tully-Geneseo formations. Thus, in contrast with the widely cited eustatic curve of Johnson et al. (1985), which

  6. Revised Phase II Plan for the National Education Practice File Development Project Including: Creation; Pilot Testing; and Evaluation of a Test Practice File. Product 1.7/1.8 (Product 1.6 Appended).

    ERIC Educational Resources Information Center

    Benson, Gregory, Jr.; And Others

    A detailed work plan is presented for the conduct of Phase II activities, which are concerned with creating a pilot test file, conducting a test of it, evaluating the process and input of the file, and preparing the file management plan. Due to the outcomes of activities in Phase I, this plan was revised from an earlier outline. Included in the…

  7. Lead atmospheric deposition rates and isotopic trends in Asian dust during the last 9.5 kyr recorded in an ombrotrophic peat bog on the eastern Qinghai-Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Ferrat, Marion; Weiss, Dominik J.; Dong, Shuofei; Large, David J.; Spiro, Baruch; Sun, Youbin; Gallagher, Kerry

    2012-04-01

    A full understanding of the atmospheric Pb cycle in Asia during the Holocene is key to palaeoclimate studies of past atmospheric circulation patterns, as well as to assess the impact of increasing industrial activities in this region. However, long-term records of atmospheric Pb isotopic trends in Asia are still sparse. Consequently, we study changes in the concentrations, fluxes and isotopic signature of deposited Pb contained in a 14C-dated peat core from the eastern Qinghai-Tibetan Plateau, dating back to 9.5 kyr BP, and present the first peat record of the changing isotopic composition of atmospheric Pb in dust in Asia during this time. Lead concentrations and fluxes vary between 2.96-21.58 μg g-1 and 0.06-3.52 mg m-2 y-1, respectively, with an average Pb baseline of 6.80 ± 4.18 μg g-1. These values agree with other Pb studies of lake and peat archives in China but are one order of magnitude larger than early and mid-Holocene values measured in Europe. Lead isotopic variability throughout the core is small, varying between 206Pb/207Pb = 1.190-1.197, 206Pb/204Pb = 18.648-18.786, 207Pb/204Pb = 15.666-15.694 and 208Pb/204Pb = 38.890-39.090. The application of Bayesian trans-dimensional changepoint modelling to the Pb dataset enabled the identification of eight significant changes in the isotopic composition of the deposited Pb. Such changes mark different phases of atmospheric Pb deposition, and hence variations in atmospheric circulation patterns and environmental conditions. Temporal variations in the potential natural and/or anthropogenic Pb sources are assessed based on the 206Pb, 207Pb, 208Pb and 204Pb isotopic composition and the 1/[Pb] ratio of the peat samples. Our results suggest that Pb deposition throughout the Holocene was governed by local deposition and long-range input from natural dust sources in northwestern (Taklamakan desert and Qaidam basin) and northern China (Badain Jaran and Tengger deserts). Input from the northern sources seems to have

  8. Results of Wagner SL revision stem with impaction bone grafting in revision total hip arthroplasty

    PubMed Central

    Singh, Somesh P; Bhalodiya, Haresh P

    2013-01-01

    Background: As the number of total hip arthroplasties (THAs) performed increases, so do the number of required revisions. Impaction bone grafting with Wagner SL Revision stem is a good option for managing bone deficiencies arising from aseptic osteolysis. We studied the results of cementless diaphyseal fixation in femoral revision after total hip arthroplasty and whether there was spontaneous regeneration of bone stock in the proximal femur after the use of Wagner SL Revision stem (Zimmer, Warsaw, IN, USA) with impaction bone grafting. Materials and Methods: We performed 53 hip revisions using impaction bone grafting and Wagner SL Revision stems in 48 patients; (5 cases were bilateral) for variety of indications ranging from aseptic osteolysis to preiprosthetic fractures. The average age was 59 years (range 44-68 years). There were 42 male and 6 female patients. Four patients died after surgery for reasons unrelated to surgery. 44 patients were available for complete analysis. Results: The mean Harris Hip Score was 42 before surgery and improved to 86 by the final followup evaluation at a mean point of 5.5 years. Of the 44 patients, 87% (n=39) had excellent results and 10% (n=5) had good results. The stem survival rate was 98% (n=43). Conclusion: Short term results for revision THA with impaction bone grafting and Wagner SL revision stems are encouraging. However, it is necessary to obtain long term results through periodic followup evaluation, as rate of complications may increase in future. PMID:23960279

  9. Revision Rhinoplasty: What Can We Learn from Error Patterns? An Analysis of Revision Surgery.

    PubMed

    East, Charles; Kwame, Ivor; Hannan, Saiful Alam

    2016-08-01

    Of the many challenges in rhinoplasty, achieving a satisfactory outcome at the first operation is important. There are multiple reasons for secondary surgery, and generally revisions can be broadly classified into minor (often one area of deficit) or a total redo. Understanding the common technical reasons for failure in primary surgery by analyzing the deformities has resulted in various error patterns emerging. Understanding these patterns means we can modify techniques in primary surgery to reduce the incidence of revision. This article describes our prospective revision rhinoplasty experience over 5 and then 2 years, highlighting the main error patterns encountered. We also describe a stepwise analysis of four frequently encountered key problem areas alongside techniques to address them and offer pearls to help prevent further revision. Comparison of two cohorts of patients from a teaching hospital setting and private practice with the same operating surgeon indicates an increasing tendency to the open approach for revisions. The re-revision rates for these groups are 15.7 and 9%, respectively. Revision rhinoplasty is a difficult operation to perform to the satisfaction of both the surgeon and the patient. Understanding the common technical reasons for failure in primary surgery by fully analyzing the deformities means we can modify techniques in primary surgery to reduce the incidence of revision. PMID:27494585

  10. Femoral tunnel malposition in ACL revision reconstruction.

    PubMed

    Morgan, Joseph A; Dahm, Diane; Levy, Bruce; Stuart, Michael J

    2012-11-01

    The Multicenter Anterior Cruciate Ligament (ACL) Revision Study (MARS) group was formed to study a large cohort of revision ACL reconstruction patients. The purpose of this subset analysis study of the MARS database is to describe specific details of femoral tunnel malposition and subsequent management strategies that surgeons chose in the revision setting. The design of this study is a case series. The multicenter MARS database is compiled from a questionnaire regarding 460 ACL reconstruction revision cases returned by 87 surgeons. This subset analysis described technical aspects and operative findings in specifically those cases in which femoral tunnel malposition was cited as the cause of primary ACL reconstruction failure. Of the 460 revisions included for study, 276 (60%) cases cited a specific "technical cause of failure." Femoral tunnel malposition was cited in 219 (47.6%) of 460 cases. Femoral tunnel malposition was cited as the only cause of failure in 117 cases (25.4%). Surgeons judged the femoral tunnel too vertical in 42 cases (35.9%), too anterior in 35 cases (29.9%), and too vertical and anterior in 31 cases (26.5%). Revision reconstruction involved the drilling of an entirely new femoral tunnel in 91 cases (82.1%). For primary reconstruction, autograft tissue was used in 82 cases (70.1%). For revision reconstruction, autograft tissue was used in 61 cases (52.1%) and allograft tissue in 56 cases (47.9%). Femoral tunnel malposition in primary ACL reconstruction was the most commonly cited reason for graft failure in this cohort. Graft selection is widely variable among surgeons.

  11. Femoral Tunnel Malposition in ACL Revision Reconstruction

    PubMed Central

    Morgan, Joseph A.; Dahm, Diane; Levy, Bruce; Stuart, Michael J.

    2013-01-01

    The Multicenter Anterior Cruciate Ligament (ACL) Revision Study (MARS) group was formed to study a large cohort of revision ACL reconstruction patients. The purpose of this subset analysis study of the MARS database is to describe specific details of femoral tunnel malposition and subsequent management strategies that surgeons chose in the revision setting. The design of this study is a case series. The multicenter MARS database is compiled from a questionnaire regarding 460 ACL reconstruction revision cases returned by 87 surgeons. This subset analysis described technical aspects and operative findings in specifically those cases in which femoral tunnel malposition was cited as the cause of primary ACL reconstruction failure. Of the 460 revisions included for study, 276 (60%) cases cited a specific “technical cause of failure.” Femoral tunnel malposition was cited in 219 (47.6%) of 460 cases. Femoral tunnel malposition was cited as the only cause of failure in 117 cases (25.4%). Surgeons judged the femoral tunnel too vertical in 42 cases (35.9%), too anterior in 35 cases (29.9%), and too vertical and anterior in 31 cases (26.5%). Revision reconstruction involved the drilling of an entirely new femoral tunnel in 91 cases (82.1%). For primary reconstruction, autograft tissue was used in 82 cases (70.1%). For revision reconstruction, autograft tissue was used in 61 cases (52.1%) and allograft tissue in 56 cases (47.9%). Femoral tunnel malposition in primary ACL reconstruction was the most commonly cited reason for graft failure in this cohort. Graft selection is widely variable among surgeons. PMID:23150344

  12. Uranium hexafluoride: A manual of good handling practices. Revision 7

    SciTech Connect

    1995-01-01

    The United States Enrichment Corporation (USEC) is continuing the policy of the US Department of Energy (DOE) and its predecessor agencies in sharing with the nuclear industry their experience in the area of uranium hexafluoride (UF{sub 6}) shipping containers and handling procedures. The USEC has reviewed Revision 6 or ORO-651 and is issuing this new edition to assure that the document includes the most recent information on UF{sub 6} handling procedures and reflects the policies of the USEC. This manual updates the material contained in earlier issues. It covers the essential aspects of UF{sub 6} handling, cylinder filling and emptying, general principles of weighing and sampling, shipping, and the use of protective overpacks. The physical and chemical properties of UF{sub 6} are also described. The procedures and systems described for safe handling of UF{sub 6} presented in this document have been developed and evaluated during more than 40 years of handling vast quantities of UF{sub 6}. With proper consideration for its nuclear properties, UF{sub 6} may be safely handled in essentially the same manner as any other corrosive and/or toxic chemical.

  13. Change in the Nd isotopic composition of the bottom water and detrital sediments on the Bering Slope over the last 500 kyrs with implications for the formation of the North Pacific Intermediate Water

    NASA Astrophysics Data System (ADS)

    Jang, K.; Huh, Y.; Han, Y.

    2015-12-01

    The Bering Sea is a potential location for the formation of the North Pacific Intermediate/Deep Water (NPIW/NPDW) and may play an important role in the global heat distribution. We reconstructed the neodymium isotopic ratio (ɛNd) of authigenic Fe-Mn oxide coatings and detrital sediments on the Bering Slope (IODP Expedition 323 site U1345; water depth 1008 m) over the last 500 kyrs. The ɛNd is a quasi-conservative water mass tracer. We compared three different leaching techniques to assure that authigenic signals are captured without contamination from terrigenous sources: (1) leaching (3 hours) with 0.02 M hydroxylamine hydrochloride (HH) in 25% buffered acetic acid after decarbonation; sediment/solution (v/v) > 10, (2) leaching (1 hour) with 0.02 M HH in 25% buffered acetic acid without decarbonation; sediment/solution ~ 1, and (3) leaching (1 hour) with 0.005 M HH in 1.5% buffered acetic acid-0.003 M Na-EDTA without decarbonation; sediment/solution > 40. The low Al concentrations and less radiogenic ɛNdvalues indicated that method (2) is the most appropriate leaching process. The average ɛNd of the authigenic fraction over the last 500 kyrs is -3.3 ± 0.9 (1σ, n=38), with large temporal fluctuations. The ɛNd of authigenic and detrital fractions are well correlated (r2 ~ 0.66), suggesting that the bottom water composition in the Bering Sea was governed by terrigenous inflow from surrounding areas. Radiogenic ɛNd peaks (up to -1.9) seem to be influenced by radiogenic water inflow from the the Kamchatka or Aluetian arcs. The high bulk density and low b* values imply higher terrigenous versus biological contribution and enhanced sea ice formation. Subsequent brine formation would have triggered sinking of radiogenic surface water, forming the NPIW. On the other hand, non-radiogenic ɛNd troughs (down to -5.3) are observed at times of low bulk density and high b* values. We presume higher biological productivity which is supported by the high opal content at

  14. Genomic analyses reveal that partial sequence of an earlier pseudorabies virus in China is originated from a Bartha-vaccine-like strain.

    PubMed

    Ye, Chao; Guo, Jin-Chao; Gao, Jia-Cong; Wang, Tong-Yun; Zhao, Kuan; Chang, Xiao-Bo; Wang, Qian; Peng, Jin-Mei; Tian, Zhi-Jun; Cai, Xue-Hui; Tong, Guang-Zhi; An, Tong-Qing

    2016-04-01

    Pseudorabies virus (PRV), the causative agent of Aujeszky's disease, has gained increased attention in China in recent years as a result of the outbreak of emergent pseudorabies. Several genomic and partial sequences are available for Chinese emergent and European-American strains of PRV, but limited sequence data exist for the earlier Chinese strains. In this study, we determined the complete genomic sequence of one earlier Chinese strain SC and one emergent strain HLJ8. Compared with other known sequences, we demonstrated that PRV strains from distinct geographical regions displayed divergent evolution. Additionally, we report for the first time, a recombination event between PRV strains, and show that strain SC is a recombinant of an endemic Chinese strain and a Bartha-vaccine-like strain. These results contribute to our understanding of PRV evolution.

  15. Metaphyseal bone loss in revision knee arthroplasty.

    PubMed

    Ponzio, Danielle Y; Austin, Matthew S

    2015-12-01

    The etiology of bone loss encountered during revision total knee arthroplasty (TKA) is often multifactorial and can include stress shielding, osteolysis, osteonecrosis, infection, mechanical loss due to a grossly loose implant, and iatrogenic loss at the time of implant resection. Selection of the reconstructive technique(s) to manage bone deficiency is determined by the location and magnitude of bone loss, ligament integrity, surgeon experience, and patient factors including the potential for additional revision, functional demand, and comorbidities. Smaller, contained defects are reliably managed with bone graft, cement augmented with screw fixation, or modular augments. Large metaphyseal defects require more extensive reconstruction such as impaction bone grafting with or without mesh augmentation, prosthetic augmentation, use of bulk structural allografts, or use of metaphyseal cones or sleeves. While each technique has advantages and disadvantages, the most optimal method for reconstruction of large metaphyseal bone defects during revision TKA is not clearly established. PMID:26362647

  16. Changes in the occurrence of heavy metals in polar ice during the last climatic cycles, with special emphasis on the possible link between cosmic dust accretion rate and the 100kyr cycle

    NASA Astrophysics Data System (ADS)

    Gabrielli, P.; Barbante, C.; Planchon, F. A. M.; Ferrant, C. P.; Delmonte, B.; Boutron, C. F.

    2003-05-01

    During the last decades, ice cores drilled in Antarctica and in Greenland have provided time series of data that have allowed the characterisation of variations of natural and anthropogenic heavy metals in the past atmosphere. Nevertheless, the interactions of heavy metals with climate change and their transport patterns remain largely unknown during the last climatic cycles. Hereafter we present our project dealing with the assessment of past changes of various heavy metals in Antarctic and Greenland ice during the past = 500kyr anticipating some preliminary Zn measurements in the EPICA Dome C ice core back to about 200000years. In our project special emphasis is given to Pt group elements (PGE) that are tracers of interplanetary dust particles (IDPs). Tracers of crustal material, volcanic activity and ocean paleoproductivity are also investigated. At the moment we are focusing especially on the ongoing EPICA Dome C Antarctic ice core, decontaminating mechanically some section and perfonning preliminary measurements of Zn and Al using Graphite Fumace Atomic Absorption Spectrometry and adopting ultraclean procedures. These data confinn the prominent continental origin of Zn in the East Antarctic ice during the last and penultimate glacial period.

  17. Ocean Optics Protocols for Satellite Ocean Color Sensor Validation, Revision 4, Volume IV: Inherent Optical Properties: Instruments, Characterizations, Field Measurements and Data Analysis Protocols

    NASA Technical Reports Server (NTRS)

    Mueller, J. L.; Fargion, G. S.; McClain, C. R. (Editor); Pegau, S.; Zanefeld, J. R. V.; Mitchell, B. G.; Kahru, M.; Wieland, J.; Stramska, M.

    2003-01-01

    This document stipulates protocols for measuring bio-optical and radiometric data for the Sensor Intercomparision and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) Project activities and algorithm development. The document is organized into 6 separate volumes as Ocean Optics Protocols for Satellite Ocean Color Sensor Validation, Revision 4. Volume I: Introduction, Background, and Conventions; Volume II: Instrument Specifications, Characterization and Calibration; Volume III: Radiometric Measurements and Data Analysis Methods; Volume IV: Inherent Optical Properties: Instruments, Characterization, Field Measurements and Data Analysis Protocols; Volume V: Biogeochemical and Bio-Optical Measurements and Data Analysis Methods; Volume VI: Special Topics in Ocean Optics Protocols and Appendices. The earlier version of Ocean Optics Protocols for Satellite Ocean Color Sensor Validation, Revision 3 is entirely superseded by the six volumes of Revision 4 listed above.

  18. Ocean Optics Protocols for Satellite Ocean Color Sensor Validation. Volume 4; Inherent Optical Properties: Instruments, Characterizations, Field Measurements and Data Analysis Protocols; Revised

    NASA Technical Reports Server (NTRS)

    Mueller, J. L. (Editor); Fargion, Giuletta S. (Editor); McClain, Charles R. (Editor); Pegau, Scott; Zaneveld, J. Ronald V.; Mitchell, B. Gregg; Kahru, Mati; Wieland, John; Stramska, Malgorzat

    2003-01-01

    This document stipulates protocols for measuring bio-optical and radiometric data for the Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) Project activities and algorithm development. The document is organized into 6 separate volumes as Ocean Optics Protocols for Satellite Ocean Color Sensor Validation, Revision 4. Volume I: Introduction, Background and Conventions; Volume II: Instrument Specifications, Characterization and Calibration; Volume III: Radiometric Measurements and Data Analysis Methods; Volume IV: Inherent Optical Properties: Instruments, Characterization, Field Measurements and Data Analysis Protocols; Volume V: Biogeochemical and Bio-Optical Measurements and Data Analysis Methods; Volume VI: Special Topics in Ocean Optics Protocols and Appendices. The earlier version of Ocean Optics Protocols for Satellite Ocean Color Sensor Validation, Revision 3 (Mueller and Fargion 2002, Volumes 1 and 2) is entirely superseded by the six volumes of Revision 4 listed above.

  19. Arthroscopic Hip Revision Surgery for Residual FAI

    PubMed Central

    Larson, Christopher M.; Giveans, Russell; Bedi, Asheesh; Samuelson, Kathryn M.; Stone, Rebecca M.

    2014-01-01

    Objectives: There is a steep surgical learning curve when managing femoroacetabular impingement (FAI) and residual FAI can lead to continued pain and disability. There is very limited data reporting outcomes after revision arthroscopy for residual FAI. Methods: The records of patients that underwent arthroscopic hip revision surgery for residual FAI based on plain radiographs and 3D CT scans were reviewed. Pre and post-operative structural pathomorphology, intra-operative findings, and pre and post-operative outcomes measures using Modified Harris Hip Scoring (MHHS), SF-12 scoring, and pain on a visual analogue scale (VAS) were evaluated. Outcomes after revision arthroscopic FAI correction were compared to a cohort that underwent primary arthroscopic FAI correction. Results: 59 patients (85 hips) underwent arthroscopic revision FAI correction (mean 20.8 months follow-up). There were 98 previous arthroscopic surgeries and 4 previous surgical dislocations. There were 39 males and 46 females with a mean age of 29.5 years (range 16 - 59). 80 hips had residual cam-type FAI, and 64 hips had residual pincer-type FAI and underwent femoral and rim resections, respectively. The labrum was debrided in 27 hips, repaired in 48 hips and reconstructed with allograft in 8 hips. Adhesions were excised for 54 hips. The results of revision arthroscopic FAI correction were compared to 154 patients (169 hips) that underwent primary arthroscopic FAI correction (mean 25.2 months follow-up). The mean improvement for outcomes scores after revision FAI correction was 18.9 points (MHHS, p<.01), 13.4 points (SF-12, p<.01), and 2.2 points (VAS, p<.01) compared to 23.7 points (MHHS, p<.01), 22.3 points (SF-12, p<.01), and 4.6 points (VAS, p<.01) after primary arthroscopic FAI correction. Most recent outcomes scores and mean improvement in outcome scores were significantly better after primary (81.1% good/ excellent results) compared to revision (69.8% good/excellent results) FAI correction (MHS

  20. Recent Title V operating permit program revisions

    SciTech Connect

    Nicewander, M.

    1995-12-31

    The purpose of this paper is to discuss recent EPA proposed regulations regarding required procedures to be incorporated into the state operating permit programs to accommodate permit revisions. The development and implementation of an operating permits program must balance air pollution control requirements with the ability of a source to meet changing market demands. This has been the major item of concern during the operating permits program development. Before discussing the specific procedures for revising operating permits, it is necessary to include some generic background information for familiarization with the operating permits program.

  1. Taxonomic revision of Richardiodes Hendel (Diptera, Richardiidae).

    PubMed

    Wendt, Lisiane Dilli; Ale-Rocha, Rosaly

    2016-01-01

    Richardiodes Hendel is a genus scarcely known taxonomically and two species are recognized: Richardiodes rectinervis Hendel from Brazilian Amazon and R. trimaculata Hennig from Peru. Herein, these two species are revised and illustrated. Examination of non-type specimens revealed considerable variation in the general body color, and the geographic distribution of each species has been expanded, especially of R. rectinervis. The limits of the genus are revised and better supported with the addition of new diagnostic characters. The male and female terminalia are described and illustrated for the first time. PMID:27394237

  2. Complications of Primary and Revision Functional Endoscopic Sinus Surgery for Chronic Rhinosinusitis

    PubMed Central

    Krings, James G.; Kallogjeri, Dorina; Wineland, Andre; Nepple, Kenneth G.; Piccirillo, Jay F.; Getz, Anne E.

    2014-01-01

    Objective The goal of this study was to determine the incidence of major complications following primary and revision functional endoscopic sinus surgery (FESS). Additionally, this study aimed to determine factors associated with the occurrence of complications including patient and provider characteristics and the use of image guidance system (IGS) technology. Study Design Retrospective cohort analysis of California and Florida all-payer databases from 2005–2008. Methods The rates of major surgical complications (skull base, orbital, and hemorrhagic) after primary and revision FESS were calculated, and bivariate analyses were performed to investigate relationships of complications with demographic and clinical characteristics. A multivariate model was used to determine risk factors for the occurrence of major complications. Results Among 78,944 primary FESS cases, 288 major complications were identified representing a complication rate of 0.36% (95% CI 0.32%–0.40%). The major complication rate following revision cases (n = 19; 0.46%) and primary cases (n = 288; 0.36%) was similar (OR=1.26; 95% CI 0.79–2.00). Multivariate analysis showed that patients who were >40 years old, had a primary payer of Medicaid, had surgery involving the frontal sinus, or had image guidance during surgery were at higher risk for major complications. Conclusion The rate of major complications (0.36%) associated with primary FESS is lower than earlier reports. The rate of major complications following revision FESS (0.46%) was found to be similar to primary cases. IGS, insurance status, age, and extent of surgery were found to be associated with an increased risk of major complications following FESS. PMID:24122737

  3. Joint Line Reconstruction in Navigated Total Knee Arthroplasty Revision

    ClinicalTrials.gov

    2012-05-16

    Revision Total Knee Arthroplasty Because of; Loosening; Instability; Impingement; or Other Reasons Accepted as Indications for TKA Exchange.; The Focus is to Determine the Precision of Joint Line Restoration in Navigated vs. Conventional Revision Total Knee Arthroplasty

  4. 78 FR 2675 - Revised Jurisdictional Thresholds of the Clayton Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-14

    ... From the Federal Register Online via the Government Publishing Office FEDERAL TRADE COMMISSION Revised Jurisdictional Thresholds of the Clayton Act AGENCY: Federal Trade Commission. ACTION: Notice. SUMMARY: The Federal Trade Commission announces the revised thresholds for interlocking...

  5. Body mass prediction from stature and bi-iliac breadth in two high latitude populations, with application to earlier higher latitude humans.

    PubMed

    Ruff, Christopher; Niskanen, Markku; Junno, Juho-Antti; Jamison, Paul

    2005-04-01

    Previous studies have indicated that body mass can be estimated from stature and bi-iliac (maximum pelvic) breadth with reasonable accuracy in modern humans, supporting the use of this method to estimate body mass in earlier human skeletal samples. However, to date the method has not been tested specifically on high latitude individuals, whose body form in some ways more closely approximates that of earlier higher latitude humans (i.e., large and broad-bodied). In this study, anthropometric data for 67 Alaskan Inupiat and 54 Finnish adults were used to test the stature/bi-iliac body mass estimation method. Both samples are very broad-bodied, and the Finnish sample is very tall as well. The method generally works well in these individuals, with average directional biases in body mass estimates of 3% or less, except in male Finns, whose body masses are systematically underestimated by an average of almost 9%. A majority of individuals in the total pooled sample have estimates to within +/-10% of their true body masses, and more than three-quarters have estimates to within +/-15%. The major factor found to affect directional bias is shoulder to hip breadth (biacromial/bi-iliac breadth). Male Finns have particularly wide shoulders, which may in part explain their systematic underestimation. New body mass estimation equations are developed that include the new data from this study. When applied to a sample of earlier (late middle Pleistocene to early Upper Paleolithic) higher latitude skeletal specimens, differences between previous and new body estimates are small (less than 2%). However, because the Finns significantly extend the range of morphological variation beyond that represented in the original world-wide reference sample used in developing the method, thereby increasing its generality, it is recommended that these new formulas be used in subsequent body mass estimations.

  6. Earlier age at menarche is associated with higher diabetes risk and cardiometabolic disease risk factors in Brazilian adults: Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

    PubMed Central

    2014-01-01

    Objectives Early menarche has been linked to higher risk of type 2 diabetes in Western and Asian societies, yet whether age at menarche is associated with diabetes in Latin America, where puberty and diabetes may have different life courses, is unknown. We tested the hypothesis that earlier menarche is associated with higher diabetes risk in Brazilian adults. Methods We used data from 8,075 women aged 35-74 years in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) who had complete information on age at menarche, diabetes status, and covariates. Diabetes was defined based on self-reported physician diagnosis, medication use, and laboratory variables (fasting glucose, 2-hour glucose, and glycated hemoglobin). Poisson regression was used to generate risk ratios (RR) and 95% confidence intervals (CI). Results Menarche onset < 11 years [vs. 13-14 years (referent)] was associated with higher risk of diabetes (RR = 1.34; 95% CI: 1.14-1.57) after adjusting for sociodemographic factors, maternal education, maternal and paternal diabetes, and birth weight. This persisted after further control for BMI at age 20 years and relative leg length. Additionally, among those not taking diabetes medications, earlier menarche [<11 years vs. 13-14 years (referent)] was associated with higher % glycated hemoglobin (p < 0.001), alanine aminotransferase (p < 0.001), triglycerides (p < 0.001), C-reactive protein (p = 0.003), waist circumference (p < 0.001), and BMI measured at baseline exam (p < 0.001). Conclusion These findings support the hypothesis that earlier menarche is associated with greater risk for adult diabetes and cardiometabolic disease in the Brazilian context. PMID:24438044

  7. Ultra-deep sequencing leads to earlier and more sensitive detection of the tyrosine kinase inhibitor resistance mutation T315I in chronic myeloid leukemia

    PubMed Central

    Baer, Constance; Kern, Wolfgang; Koch, Sarah; Nadarajah, Niroshan; Schindela, Sonja; Meggendorfer, Manja; Haferlach, Claudia; Haferlach, Torsten

    2016-01-01

    Chronic myeloid leukemia cells acquire resistance to tyrosine kinase inhibitors through mutations in the ABL1 kinase domain. The T315I mutation mediates resistance to imatinib, dasatinib, nilotinib and bosutinib, whereas sensitivity to ponatinib remains. Mutation detection by conventional Sanger sequencing requires 10%–20% expansion of the mutated subclone. We studied the T315I mutation development by ultra-deep sequencing on the 454 XL+ platform (Roche) in comparison to Sanger sequencing. By ultra-deep sequencing, mutations were detected at loads of 1%–2%. We selected 40 patients who had failed first-line to third-line treatment (imatinib, dasatinib, nilotinib) and had high loads of the T315I mutation detected by Sanger sequencing. We confirmed T315I mutations by ultra-deep sequencing and investigated the mutation dynamics by backtracking earlier samples. In 20 of 40 patients, we identified the T315I three months (median) before Sanger sequencing detection limits were reached. To exclude sporadic low percentage mutation development without subsequent mutation outgrowth, we selected 42 patients without resistance mutations detected by Sanger sequencing but loss of major molecular response. Here, no mutation was detected by ultradeep sequencing. Additional non-T315I resistance mutations were found in 20 of 40 patients. Only 15% had two mutations per cell; the other cases showed multiple independently mutated clones and the T315I clone demonstrated a rapid outgrowth. In conclusion, T315I mutations could be detected earlier by ultra-deep sequencing compared to Sanger sequencing in a selected group of cases. Earlier mutation detection by ultra-deep sequencing might allow treatment to be changed before clonal increase of cells with the T315I mutation. PMID:27102501

  8. 7 CFR 3015.115 - Budget revisions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Budget revisions. 3015.115 Section 3015.115 Agriculture Regulations of the Department of Agriculture (Continued) OFFICE OF THE CHIEF FINANCIAL OFFICER, DEPARTMENT OF AGRICULTURE UNIFORM FEDERAL ASSISTANCE REGULATIONS Programmatic Changes and Budget...

  9. The Copyright Revision Act of 1976.

    ERIC Educational Resources Information Center

    Kintner, Earl W.; And Others

    Though not exhaustive, this report explains the substantive aspects of the Copyright Revision Act of 1976 that would be of interest to copyright proprietors and/or users of copyrightable works. The major part of the report deals with the subject matter and scope of copyright; topics discussed include fair use, reproduction by libraries and…

  10. Revising the White Racial Consciousness Development Scale

    ERIC Educational Resources Information Center

    Lee, Sang Min; Puig, Ana; Pasquarella-Daley, Lauren; Denny, George; Rai, Ann Allen; Dallape, Aprille; Parker, Woodrow Max

    2007-01-01

    This article describes the revision of the White Racial Consciousness Development Scale (D. Claney & W. M. Parker, 1989). A multistage approach including item generation, item refinement and selection, and evaluation of score validity and reliability was used to test construction and validation. Implications for theory, practice, and future…

  11. ESL Curriculum Revision: Shifting Paradigms for Success

    ERIC Educational Resources Information Center

    Ewert, Doreen E.

    2011-01-01

    The early success of the revised ESL literacy development curriculum for international undergraduates at a large Midwestern university suggests that a curriculum which integrates reading and writing activity around meaning-making tasks with texts and focuses on fluency before accuracy is preferable to a skill-based curriculum. Support for this…

  12. More Than A Native Speaker, Revised Edition

    ERIC Educational Resources Information Center

    Snow, Don, Ed.

    2006-01-01

    This revised edition includes an expanded discussion of student-directed language learning, workbook activities for volunteer teachers enrolled in courses or studying the book individually, and a full array of culture-based discussion topics for use as supplementary activities or core material for an English course. The book includes 16 chapters.…

  13. 77 FR 33786 - NRC Enforcement Policy Revision

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-07

    ..., 2010 (75 FR 60485), announcing a revision to the Policy. The Commission also directed the NRC staff to reevaluate the portions of the Policy associated with construction activities (e.g., reactor or uranium... notice (FRN) published on August 9, 2011 (76 FR 48919), the NRC solicited written comments...

  14. Revision Planned for the Cambridge Latin Course.

    ERIC Educational Resources Information Center

    Sebesta, Judith Lynn

    1980-01-01

    Summarizes a discussion on the revision of the Cambridge Latin Course (CLC) held during the 1980 ACL Institute at the University of New Hampshire by CLC users and Cambridge University Press representatives. Emphasizes suggestions by users on grammar instruction strategies better suited to American students' needs. (MES)

  15. 78 FR 48667 - Revised Company Registration System

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-09

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Revised Company Registration System AGENCY: Federal Energy Regulatory... Registration System. The Commission issued a previous notice in the Federal Register, 78 FR 44559 (July...

  16. Revised Recommendation Concerning Technical and Vocational Education.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France).

    The UNESCO (United Nations Education, Scientific, and Cultural Organization) revised recommendation setting forth general principles, goals, and guidelines concerning technical and vocational education (adopted by the General Conference at its 18th session in Paris, 19 November 1974) is presented under the following headings: (1) Technical and…

  17. Anomalies of Nuclear Criticality, Revision 6

    SciTech Connect

    Clayton, E. D.; Prichard, Andrew W.; Durst, Bonita E.; Erickson, David; Puigh, Raymond J.

    2010-02-19

    This report is revision 6 of the Anomalies of Nuclear Criticality. This report is required reading for the training of criticality professionals in many organizations both nationally and internationally. This report describes many different classes of nuclear criticality anomalies that are different than expected.

  18. New Ways of Classroom Assessment. Revised

    ERIC Educational Resources Information Center

    Brown, J. D., Ed.

    2013-01-01

    In this revised edition in the popular New Ways Series, teachers have once again been given an opportunity to show how they do assessment in their classrooms on an everyday basis. Often feeling helpless when confronted with large-scale standardized testing practices, teachers here offer classroom testing created with the direct aim of helping…

  19. Revision of Benedictus Scherer (Coleoptera: Chrysomelidae: Galerucinae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The alpine flea beetle genus Benedictus Scherer (Coleoptera: Chrysomelidae: Galerucinae) is revised. Twenty new species, namely B. chilalla, B. dochula, B. ha, B. nobding, B. thumsila and B. yatongla from Bhutan, B. belousovi, B. cangshanicus, B. kabaki, B. kurbatovi, B. nigrinus, B. sichuanensis a...

  20. Relating Revision Skills to Teacher Commentary.

    ERIC Educational Resources Information Center

    Sweeney, Marilyn Ruth

    1999-01-01

    Considers how the revising skills of basic writing students improve when they receive both inductive and deductive teacher feedback. Finds that students who received inductive feedback changed their largest percent of errors when given oral conferences and students who received deductive feedback changed their smallest number of errors when given…

  1. Draft: Standards for College Libraries; 1975 Revision.

    ERIC Educational Resources Information Center

    Givens, Johnnie; And Others

    1974-01-01

    Prepared by the Association of College and Research Libraries Ad Hoc Committee to Revise the 1959 Standards, these standards are designed to assess the adequacy of libraries serving liberal arts programs at the bachelors and masters degree levels. They may also be applied to small university libraries. They attempt to synthesize and articulate the…

  2. 76 FR 2291 - TRICARE Reimbursement Revisions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-13

    ... assistants and assistant-at-surgery claims; and this rule revises the regulation by removing references to... Assistant-at-Surgery The current regulatory language references specific reimbursement percentages for assistant-at-surgery reimbursement. Rather than including these specific percentage amounts, which...

  3. Surgical revision of the upper eyelid fold.

    PubMed

    Cies, W A; Baylis, H I

    1975-12-01

    We performed surgery on 107 patients primarily with blepharoptosis and eyelid fold abnormalities, between 1973 and 1974. Production of an eyelid fold at the time of an initial blepharoptosis procedure should be a primary goal. Lack of a distinct symmetrical upper eyelid fold constituted a cosmetic blemish and necessitated revision.

  4. Needs Assessment for Continuous Curriculum Revision.

    ERIC Educational Resources Information Center

    Weddington, Doris

    Continuous curriculum revision in community/junior colleges can be provided by treating the curriculum as a self-correcting set of systems with feedback loops and marginal sensors which supply information needed for constant system evaluation. This curriculum-related set of sub-systems is comprised of the institution, the curriculum, programs, and…

  5. 43 CFR 1610.5-6 - Revision.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Revision. 1610.5-6 Section 1610.5-6 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR GENERAL MANAGEMENT (1000) PLANNING, PROGRAMMING, BUDGETING Resource...

  6. 78 FR 35812 - Revisions to Procedural Rules

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-14

    ... substantially nationwide) change in the nature of service. The proposed revisions are intended to expedite... Counsel, at 202-789-6820. SUPPLEMENTARY INFORMATION: Regulatory history: 77 FR 23176 (April 18, 2012... series of orders addressing the need for more timely completion of nature of service proceedings....

  7. Migrant Education Administration Handbook. [Revised 1972].

    ERIC Educational Resources Information Center

    Taylor, Y. A.

    The purpose of this revised handbook is to supply information and provide answers to many of the questions pertaining to the administration of migrant education projects in North Carolina. The Federal program is described in terms of legislation affecting migrants, definition of a migratory child, and contracts for studies and surveys. Also…

  8. Early Screening Inventory. Revised. Examiner's Manual.

    ERIC Educational Resources Information Center

    Meisels, Samuel J.; Marsden, Dorothea B.; Wiske, Martha Stone; Henderson, Laura W.

    The Early Screening Inventory-Revised (ESI-R) is a brief developmental screening instrument that is individually administered to children from 3 to 6 years of age. It is designed to identify children who may need special education services in order to perform successfully in school. The ESI-R is intended to assess the child's ability to acquire…

  9. CO2 laser in revision stapes surgery

    NASA Astrophysics Data System (ADS)

    Jovanovic, Sergije; Schoenfeld, Uwe; Scherer, Hans H.

    1997-05-01

    Successful restoration of audition in revision stapedotomies involves precise identification and correction of the pathological condition without traumatizing the inner ear. Conventional surgical procedures often lead to unsatisfactory audition results and inner ear damages. In revision stapedotomy, the carbon-dioxide laser provides the ear surgeon with three important advantages over the conventional technique: (1) improved diagnostic and therapeutic precision, (2) better stabilization of the new prosthesis in the oval niche, and (3) reduction of inner ear trauma through non- contact atraumatic management. The surgical procedure of revision stapedotomies with the carbon dioxide laser is discussed, and case examples are used to illustrate the diversity of pathological conditions that can be treated by carbon-dioxide laser surgery. Our experience with revision carbon-dioxide laser stapedotomy suggests an improvement of postoperative audition compared to the conventional technique and demonstrates a significant elimination of sensorineural deafness. The carbon-dioxide laser enables the ear surgeon to precisely and reliably correct conduction deafness recurring after stapedotomy.

  10. Personalisation: The Emerging "Revised" Code of Education?

    ERIC Educational Resources Information Center

    Hartley, David

    2007-01-01

    In England, a "revised" educational code appears to be emerging. It centres upon the concept of "personalisation". Its basis is less in educational theory, more in contemporary marketing theory. Personalisation can be regarded in two ways. First, it provides the rationale for a new mode of public-service delivery, one which seeks to enable "users"…

  11. Geography: A Guide to Reference Sources. [Revised].

    ERIC Educational Resources Information Center

    Marley, Carol

    This revised annotated bibliography about geography concentrates on reference materials located in the McLennan Library of McGill University (Montreal, Quebec), and it emphasizes human rather than physical geography. The resources are presented in nine areas: (1) guides to the literature; (2) dictionaries; (3) gazeteers and place names; (4)…

  12. GROUP THINKING AND CONFERENCE LEADERSHIP. REVISED EDITION.

    ERIC Educational Resources Information Center

    UTTERBACK, WILLIAM E.

    REVISED TO INCLUDE UP-TO-DATE MATERIALS, THIS BOOK IS CONCERNED WITH COOPERATIVE THINKING AS A DEMOCRATIC PROCEDURE. IT IS ADDRESSED TO ALL WHO PARTICIPATE IN OR LEAD INFORMAL DISCUSSION IN SMALL GROUPS--COMMITTEES, STAFF MEETINGS, BOARDS, AND COUNCILS--AND TREATS IN DETAIL DISCUSSION IN THE CLASSROOM, RADIO AND TELEVISION, THE BUSINESS…

  13. 76 FR 57012 - Progress Reports Rules Revision

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-15

    ... of Prisons 28 CFR Part 524 RIN 1120-AB60 Progress Reports Rules Revision AGENCY: Bureau of Prisons, Justice. ACTION: Proposed rule. SUMMARY: In this document, the Bureau of Prisons (Bureau) proposes to..., Office of General Counsel, Bureau of Prisons, 320 First Street, NW., Washington, DC 20534. You may...

  14. Schools without Drugs. What Works. Revised Edition.

    ERIC Educational Resources Information Center

    Department of Education, Washington, DC.

    This revised edition focuses on the prevention of drug use among school students, with increased attention to alcohol, tobacco, and steroids. The handbook, which begins with an introduction by Secretary of Education, Lauro F. Cavazos, provides new information about the effects of alcohol on young people; statistics on the harm it causes; and…

  15. 22 CFR 214.14 - Charter revision.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ADVISORY COMMITTEE MANAGEMENT Establishment of Advisory...) Charter revision requires clearances by the advisory committee, the A.I.D. Advisory Committee Management... notification of the change to the Federal Register, Congressional committees, and the Library of Congress....

  16. 30 CFR 774.13 - Permit revisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Permit revisions. 774.13 Section 774.13 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR SURFACE COAL...; RENEWAL; TRANSFER, ASSIGNMENT, OR SALE OF PERMIT RIGHTS; POST-PERMIT ISSUANCE REQUIREMENTS; AND...

  17. Code of Fair Testing Practices in Education (Revised)

    ERIC Educational Resources Information Center

    Educational Measurement: Issues and Practice, 2005

    2005-01-01

    A note from the Working Group of the Joint Committee on Testing Practices: The "Code of Fair Testing Practices in Education (Code)" prepared by the Joint Committee on Testing Practices (JCTP) has just been revised for the first time since its initial introduction in 1988. The revision of the Code was inspired primarily by the revision of the…

  18. Understanding Taxes. Teacher's Resource Kit. 1995 Annual Revision.

    ERIC Educational Resources Information Center

    Internal Revenue Service (Dept. of Treasury), Washington, DC.

    This packet contains revisions of the following sections of the "Understanding Taxes" teacher's resource kit: complete revisions of lessons 3 and 4; updated student handouts for lessons 2, 9, and 11; new glossary; and revised software user's guide. Lesson 3, "From W-4 to 1040A," is designed to acquaint students with the basic tax-related forms…

  19. A National Survey of Revising Practices in the Primary Classroom

    ERIC Educational Resources Information Center

    Saddler, Bruce; Saddler, Kristie; Befoorhooz, Bita; Cuccio-Slichko, Julie

    2014-01-01

    A random national sampling of primary grade teachers in the United States were surveyed to determine how they teach revising to writers in the elementary grades. Our findings suggest that in our sample of teachers, little time is dedicated in the school day to writing and especially revising. The teachers believed that more time spent revising did…

  20. 48 CFR 252.247-7002 - Revision of prices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Revision of prices. 252... Provisions And Clauses 252.247-7002 Revision of prices. As prescribed in 247.270-4(c), use the following clause: Revision of Prices (DEC 1991) (a) Definition. Wage adjustment, as used in this clause, means...

  1. 46 CFR 8.550 - Plan review and revisions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... revisions. The CAP and VAP(s) must be reviewed and revised as follows: (1) Every 2 years after the plan... the VAP. (3) If a reportable casualty occurs, the cognizant OCMI will review the portions of the VAP... revisions to the VAP are appropriate. (4) When statutes or regulations change, the appropriate sections...

  2. 46 CFR 8.550 - Plan review and revisions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... revisions. The CAP and VAP(s) must be reviewed and revised as follows: (1) Every 2 years after the plan... the VAP. (3) If a reportable casualty occurs, the cognizant OCMI will review the portions of the VAP... revisions to the VAP are appropriate. (4) When statutes or regulations change, the appropriate sections...

  3. 46 CFR 8.550 - Plan review and revisions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... revisions. The CAP and VAP(s) must be reviewed and revised as follows: (1) Every 2 years after the plan... the VAP. (3) If a reportable casualty occurs, the cognizant OCMI will review the portions of the VAP... revisions to the VAP are appropriate. (4) When statutes or regulations change, the appropriate sections...

  4. 46 CFR 8.550 - Plan review and revisions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... revisions. The CAP and VAP(s) must be reviewed and revised as follows: (1) Every 2 years after the plan... the VAP. (3) If a reportable casualty occurs, the cognizant OCMI will review the portions of the VAP... revisions to the VAP are appropriate. (4) When statutes or regulations change, the appropriate sections...

  5. 46 CFR 8.550 - Plan review and revisions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... revisions. The CAP and VAP(s) must be reviewed and revised as follows: (1) Every 2 years after the plan... the VAP. (3) If a reportable casualty occurs, the cognizant OCMI will review the portions of the VAP... revisions to the VAP are appropriate. (4) When statutes or regulations change, the appropriate sections...

  6. 75 FR 81126 - Revisions to Lead Ambient Air Monitoring Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-27

    ..., that revised the NAAQS for lead and associated ambient air lead monitoring requirements (73 FR 66964... revisions to the requirements for both source-oriented and non-source-oriented monitoring for lead (74 FR... 1.0 tpy as part of the October 2008 lead NAAQS revisions (73 FR 66964, codified at 40 CFR part...

  7. Assessing the Impact of Peer Revision on L2 Writing.

    ERIC Educational Resources Information Center

    Villamil, Olga S.; de Guerrero, Maria C. M.

    1998-01-01

    A study investigated the impact of peer revision on writers' final drafts in two rhetorical modes, narration and persuasion, among 14 Spanish-speaking college students of English-as-a-Second-Language. Results revealed 74% of revisions made in peer sessions were incorporated into final drafts, and writers made many further self-revisions,…

  8. 50 CFR 660.717 - Framework for revising regulations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Framework for revising regulations. 660... Migratory Fisheries § 660.717 Framework for revising regulations. (a) General. NMFS will establish and..., removed, or revised. Any such action will be made according to the framework measures in section 8.3.4...

  9. 50 CFR 660.717 - Framework for revising regulations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Framework for revising regulations. 660... Migratory Fisheries § 660.717 Framework for revising regulations. (a) General. NMFS will establish and..., removed, or revised. Any such action will be made according to the framework measures in section 8.3.4...

  10. 50 CFR 660.717 - Framework for revising regulations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Framework for revising regulations. 660... Migratory Fisheries § 660.717 Framework for revising regulations. (a) General. NMFS will establish and..., removed, or revised. Any such action will be made according to the framework measures in section 8.3.4...

  11. 50 CFR 660.717 - Framework for revising regulations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Framework for revising regulations. 660... Migratory Fisheries § 660.717 Framework for revising regulations. (a) General. NMFS will establish and..., removed, or revised. Any such action will be made according to the framework measures in section 8.3.4...

  12. 50 CFR 660.717 - Framework for revising regulations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Framework for revising regulations. 660... Migratory Fisheries § 660.717 Framework for revising regulations. (a) General. NMFS will establish and..., removed, or revised. Any such action will be made according to the framework measures in section 8.3.4...

  13. Uncovering Substance: Teaching Revision in High School Classrooms

    ERIC Educational Resources Information Center

    Early, Jessica Singer; Saidy, Christina

    2014-01-01

    This article shares the process and outcomes from a three-day revision workshop designed and implemented in a diverse high school language arts classroom. The revision workshop included: direct instruction, self-reflection, and peer feedback to provide struggling writers with opportunities to take part in substantive revision. The authors examine…

  14. 78 FR 44596 - Minor Boundary Revision at Yosemite National Park

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-24

    ... National Park Service Minor Boundary Revision at Yosemite National Park AGENCY: National Park Service, Interior. ACTION: Notification of Boundary Revision. SUMMARY: The boundary of Yosemite National Park is... boundary of Yosemite National Park. DATES: The effective date of this boundary revision is July 24,...

  15. Belief revision and way-finding.

    PubMed

    Bucher, Leandra; Röser, Florian; Nejasmic, Jelica; Hamburger, Kai

    2014-02-01

    Belief revision is required when veridical information surfaces that contradicts what was previously thought to be the case. In way-finding, belief revision frequently occurs, for example, when the travelled route has led one astray, instead of to one's chosen destination. In past cognitive research, the topics of belief revision and way-finding have been treated in isolation. Here, we introduce an approach for linking the two fields and assess belief revision as it occurs in the process of way-finding. We report the results of two experiments that put participants in (virtual) situations where elements of a previously learned route description do not match the actual environment (thereby requiring the revision of a previously held belief). Experiment 1 puts participants in a highly artificial virtual environment where the landmarks to be used in navigation have a low degree of semantic salience (houses of various color). Experiment 2 puts subjects in a photorealistic environment where the objects to be used in navigation are well-known landmarks (such as the Eiffel Tower) and thus have a high degree of semantic salience. In both experiments, participants are confronted with T-junctions, where a landmark that was expected to indicate the correct route is discovered to be in an unexpected location. The results of the experiments show that a participant's choice of route, in such cases, is affected by differences in the structure of the relevant initial instruction. More precisely, the route chosen by participants is affected by whether the relevant landmark was described as being on the same side of the path as they were instructed to turn (congruent case) or as located on the opposite side of the path as they were instructed to turn (incongruent case).

  16. Television viewing and age at smoking initiation: does a relationship exist between higher levels of television viewing and earlier onset of smoking?

    PubMed

    Gutschoven, Klaas; Van den Bulck, Jan

    2005-06-01

    This cross-sectional study of children assessed the association between television viewing and age at smoking initiation, using self-reports administered by research assistants in schools. Participants were 909 students in their first and fourth years of secondary education in a random sample of 15 secondary schools in Flanders, Belgium, who had smoked at least one cigarette. The main outcome measure was age at smoking initiation. The independent variable was weekly television viewing volume. Gender, educational level, parental smoking, and peer smoking were the control variables. The relationship between television viewing and age at smoking initiation was significant. Higher levels of television viewing were related to earlier onset of smoking behavior in adolescents. The relationship of television viewing with age at smoking initiation was stronger than that of peer smoking, parental smoking, and gender. For each hour of television viewing per day, the average smoking initiation age decreased by 60 days. Heavier television viewers start smoking at an earlier age. Two possible explanations for this relationship are suggested. Social learning theory suggests that actors and actresses serve as behavioral role models for heavy viewers. Cultivation theory suggests that exposure to positive messages influences smoking attitudes. Further research should examine whether the relationship is causal and whether television acts as a provider of smoking role models or whether it influences smoking attitudes. PMID:16085505

  17. 30 CFR 585.617 - What activities require a revision to my SAP, and when will BOEM approve the revision?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false What activities require a revision to my SAP... FACILITIES ON THE OUTER CONTINENTAL SHELF Plans and Information Requirements Activities Under An Approved Sap § 585.617 What activities require a revision to my SAP, and when will BOEM approve the revision? (a)...

  18. 30 CFR 585.617 - What activities require a revision to my SAP, and when will BOEM approve the revision?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What activities require a revision to my SAP... FACILITIES ON THE OUTER CONTINENTAL SHELF Plans and Information Requirements Activities Under An Approved Sap § 585.617 What activities require a revision to my SAP, and when will BOEM approve the revision? (a)...

  19. 30 CFR 585.617 - What activities require a revision to my SAP, and when will BOEM approve the revision?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What activities require a revision to my SAP... FACILITIES ON THE OUTER CONTINENTAL SHELF Plans and Information Requirements Activities Under An Approved Sap § 585.617 What activities require a revision to my SAP, and when will BOEM approve the revision? (a)...

  20. 30 CFR 285.617 - What activities require a revision to my SAP, and when will MMS approve the revision?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What activities require a revision to my SAP... OUTER CONTINENTAL SHELF Plans and Information Requirements Activities Under An Approved Sap § 285.617 What activities require a revision to my SAP, and when will MMS approve the revision? (a) You...

  1. 30 CFR 585.634 - What activities require a revision to my COP, and when will BOEM approve the revision?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false What activities require a revision to my COP... FACILITIES ON THE OUTER CONTINENTAL SHELF Plans and Information Requirements Activities Under An Approved Cop § 585.634 What activities require a revision to my COP, and when will BOEM approve the revision? (a)...

  2. 30 CFR 285.634 - What activities require a revision to my COP, and when will MMS approve the revision?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What activities require a revision to my COP... OUTER CONTINENTAL SHELF Plans and Information Requirements Activities Under An Approved Cop § 285.634 What activities require a revision to my COP, and when will MMS approve the revision? (a) You...

  3. 30 CFR 585.634 - What activities require a revision to my COP, and when will BOEM approve the revision?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What activities require a revision to my COP... FACILITIES ON THE OUTER CONTINENTAL SHELF Plans and Information Requirements Activities Under An Approved Cop § 585.634 What activities require a revision to my COP, and when will BOEM approve the revision? (a)...

  4. 30 CFR 585.634 - What activities require a revision to my COP, and when will BOEM approve the revision?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What activities require a revision to my COP... FACILITIES ON THE OUTER CONTINENTAL SHELF Plans and Information Requirements Activities Under An Approved Cop § 585.634 What activities require a revision to my COP, and when will BOEM approve the revision? (a)...

  5. Revised potentiometric-surface map, Yucca Mountain and vicinity, Nevada

    USGS Publications Warehouse

    Ervin, E.M.; Luckey, R.R.; Burkhardt, D.J.

    1993-01-01

    The revised potentiometric-surface map presented in this report updates earlier maps of the Yucca Mountain area using mainly 1988 average water levels. Because of refinements in the corrections to the water-level measurements, these water levels have increased accuracy and precision over older values. The small-gradient area to the southeast of Yucca Mountain is contoured with a 0.25-meter interval and ranges in water-level altitude from 728.5 to 731.0 meters. Other areas with different water levels, to the north and west of Yucca Mountain, are illustrated with shaded patterns. The potentiometric surface can be divided into three regions: 1) A small-gradient area to the southeast of Yucca Mountain, which may be explained by flow through high-transmissivity rocks or low ground-water flux through the area; 2) A moderate-gradient area, on the western side of Yucca Mountain, where the water-level altitude ranges from 775 to 780 meters, and appears to be impeded by the Solitario Canyon Fault and a splay of that fault; and 3) A large-gradient area, to the north-northeast of Yucca Mountain, where water level altitude ranges from 738 to 1,035 meters, possibly as a result of a semi-perched groundwater system. Water levels from wells at Yucca Mountain were examined for yearly trends (1986-89) using linear least-squares regression. Data from five wells exhibited trends which were statistically significant, but some of those may be a result of slow equilibration of the water level from drilling in less permeable rocks. Adjustments for temperature and density changes in the deep wells with long fluid columns were attempted, but some of the adjusted data did not fit the surrounding data and, thus, were not used.

  6. Revised potentiometric-surface map, Yucca Mountain and vicinity, Nevada

    SciTech Connect

    Ervin, E.M.; Luckey, R.R.; Burkhardt, D.J.

    1994-12-01

    The revised potentiometric-surface map presented in this report updates earlier maps of the Yucca Mountain area using mainly 1988 average water levels. Because of refinements in the corrections to the water-level measurements, these water levels have increased accuracy and precision over older values. The small-gradient area to the southeast of Yucca Mountain is contoured with a 0.25-meter interval and ranges in water-level altitude from 728.5 to 73 1.0 meters. Other areas with different water levels, to the north and west of Yucca Mountain, are illustrated with shaded patterns. The potentiometric surface can be divided into three regions: (1) A small-gradient area to the southeast of Yucca Mountain, which may be explained by flow through high-transmissivity rocks or low ground-water flux through the area; (2) A moderate-gradient area, on the western side of Yucca Mountain, where the water-level altitude ranges from 775 to 780 meters, and appears to be impeded by the Solitario Canyon Fault and a splay of that fault; and (3) A large-gradient area, to the north-northeast of Yucca Mountain, where water level altitude ranges from 738 to 1,035 meters, possibly as a result of a semi-perched groundwater system. Water levels from wells at Yucca Mountain were examined for yearly trends using linear least-squares regression. Data from five wells exhibited trends which were statistically significant, but some of those may be a result of slow equilibration of the water level from drilling in less permeable rocks. Adjustments for temperature and density changes in the deep wells with long fluid columns were attempted, but some of the adjusted data did not fit the surrounding data and, thus, were not used.

  7. Guidance document for revision of DOE Order 5820.2A, Radioactive Waste Technical Support Program. Revision 1

    SciTech Connect

    Kudera, D.E.; McMurtrey, C.D.; Meagher, B.G.

    1993-04-01

    This document provides guidance for the revision of DOE Order 5820.2A, ``Radioactive Waste Management.`` Technical Working Groups have been established and are responsible for writing the revised order. The Technical Working Groups will use this document as a reference for polices and procedures that have been established for the revision process. The overall intent of this guidance is to outline how the order will be revised and how the revision process will be managed. In addition, this document outlines technical issues considered for inclusion by a Department of Energy Steering Committee.

  8. Earlier Age of Onset of Chronic Hypertension and Type 2 Diabetes Mellitus After a Hypertensive Disorder of Pregnancy or Gestational Diabetes Mellitus.

    PubMed

    Heida, Karst Y; Franx, Arie; van Rijn, Bas B; Eijkemans, Marinus J C; Boer, Jolanda M A; Verschuren, Monique W M; Oudijk, Martijn A; Bots, Michiel L; van der Schouw, Yvonne T

    2015-12-01

    A prospective cohort study was conducted to assess the impact of a history of hypertensive disorder of pregnancy (HDP) or gestational diabetes mellitus (GDM) on the risk and age of onset of hypertension, type 2 diabetes mellitus (T2D), and cardiovascular disease (CVD) later in life, independent of hypertension and T2D. Between 1993 and 1997, 22 265 ever-pregnant women were included from the European Prospective Investigation into Cancer and Nutrition-NL study, aged 20 to 70 years at baseline. Details on complications of pregnancy and known hypertension were obtained by questionnaire. Blood pressure was measured at enrollment. Participants were followed for the occurrence of CVD events. Data were analyzed using ANCOVA, multivariable logistic regression, and Cox proportional hazard (with HDP and GDM as time-dependent variables for T2D and CVD) models. At enrollment, women with a HDP reported diagnosis of hypertension 7.7 years earlier (95% confidence interval [CI] 6.9-8.5) and women with GDM reported diagnosis of T2D 7.7 years earlier (95% CI 5.8-9.6) than women without pregnancy complications. After adjustment for potential confounders, HDP was associated with presence of hypertension at enrollment (odds ratio 2.12, 95% CI 1.98-2.28) and onset of CVD later in life (hazard ratio 1.21, 95% CI 1.10-1.32). After including the intermediates hypertension and T2D in the model, the risk of CVD later in life decreased (hazard ratio 1.09, 95% CI 1.00-1.20). GDM was associated with an increased risk of developing T2D later in life (hazard ratio 3.68, 95% CI 2.77-4.90), but not with risk of CVD. HDP and GDM have a substantial impact on the risk of CVD and are potentially important indicators for preventive cardiovascular risk management.

  9. Prospective Cohort Study of Hospital Palliative Care Teams for Inpatients With Advanced Cancer: Earlier Consultation Is Associated With Larger Cost-Saving Effect

    PubMed Central

    May, Peter; Garrido, Melissa M.; Cassel, J. Brian; Kelley, Amy S.; Meier, Diane E.; Normand, Charles; Smith, Thomas J.; Stefanis, Lee; Morrison, R. Sean

    2015-01-01

    Purpose Previous studies report that early palliative care is associated with clinical benefits, but there is limited evidence on economic impact. This article addresses the research question: Does timing of palliative care have an impact on its effect on cost? Patients and Methods Using a prospective, observational design, clinical and cost data were collected for adult patients with an advanced cancer diagnosis admitted to five US hospitals from 2007 to 2011. The sample for economic evaluation was 969 patients; 256 were seen by a palliative care consultation team, and 713 received usual care only. Subsamples were created according to time to consult after admission. Propensity score weights were calculated, matching the treatment and comparison arms specific to each subsample on observed confounders. Generalized linear models with a γ distribution and a log link were applied to estimate the mean treatment effect on cost within subsamples. Results Earlier consultation is associated with a larger effect on total direct cost. Intervention within 6 days is estimated to reduce costs by −$1,312 (95% CI, −$2,568 to −$56; P = .04) compared with no intervention and intervention within 2 days by −$2,280 (95% CI, −$3,438 to −$1,122; P < .001); these reductions are equivalent to a 14% and a 24% reduction, respectively, in cost of hospital stay. Conclusion Earlier palliative care consultation during hospital admission is associated with lower cost of hospital stay for patients admitted with an advanced cancer diagnosis. These findings are consistent with a growing body of research on quality and survival suggesting that early palliative care should be more widely implemented. PMID:26056178

  10. Higher Precision in Pointing Movements of the Preferred vs. Non-Preferred Hand Is Associated with an Earlier Occurrence of Anticipatory Postural Adjustments

    PubMed Central

    Bruttini, Carlo; Esposti, Roberto; Bolzoni, Francesco; Cavallari, Paolo

    2016-01-01

    It is a common experience to exhibit a greater dexterity when performing a pointing movement with the preferred limb (PREF) vs. the non-preferred (NON-PREF) one. Here we provide evidence that the higher precision in pointing movements of the PREF vs. NON-PREF hand is associated with an earlier occurrence of the anticipatory postural adjustments (APAs). In this aim, we compared the APAs which stabilize the left or the right arm when performing a pen-pointing movement (prime mover flexor carpi radialis (FCR)). Moreover, we analyzed the elbow and wrist kinematics as well as the precision of the pointing movement. The mean kinematics of wrist movement and its latency, with respect to prime mover recruitment, were similar in the two sides, while APAs in triceps brachii (TB), biceps brachii (BB) and anterior deltoid (AD) were more anticipated when movements were performed with the PREF than with the NON-PREF hand (60–70 vs. 20–30 ms). APAs amplitudes were comparable in the muscles of the two sides. Earlier APAs in the preferred limb were associated with a better fixation of the elbow, which showed a lower excursion, and with a less scattered pointing error (PREF: 10.1 ± 0.8 mm; NON-PREF: 16.3 ± 1.7). Present results suggest that, by securing the more proximal joints dynamics, an appropriate timing of the intra-limb APAs is necessary for refining the voluntary movement precision, which is known to be scarce on the NON-PREF side. PMID:27486394

  11. Higher Precision in Pointing Movements of the Preferred vs. Non-Preferred Hand Is Associated with an Earlier Occurrence of Anticipatory Postural Adjustments.

    PubMed

    Bruttini, Carlo; Esposti, Roberto; Bolzoni, Francesco; Cavallari, Paolo

    2016-01-01

    It is a common experience to exhibit a greater dexterity when performing a pointing movement with the preferred limb (PREF) vs. the non-preferred (NON-PREF) one. Here we provide evidence that the higher precision in pointing movements of the PREF vs. NON-PREF hand is associated with an earlier occurrence of the anticipatory postural adjustments (APAs). In this aim, we compared the APAs which stabilize the left or the right arm when performing a pen-pointing movement (prime mover flexor carpi radialis (FCR)). Moreover, we analyzed the elbow and wrist kinematics as well as the precision of the pointing movement. The mean kinematics of wrist movement and its latency, with respect to prime mover recruitment, were similar in the two sides, while APAs in triceps brachii (TB), biceps brachii (BB) and anterior deltoid (AD) were more anticipated when movements were performed with the PREF than with the NON-PREF hand (60-70 vs. 20-30 ms). APAs amplitudes were comparable in the muscles of the two sides. Earlier APAs in the preferred limb were associated with a better fixation of the elbow, which showed a lower excursion, and with a less scattered pointing error (PREF: 10.1 ± 0.8 mm; NON-PREF: 16.3 ± 1.7). Present results suggest that, by securing the more proximal joints dynamics, an appropriate timing of the intra-limb APAs is necessary for refining the voluntary movement precision, which is known to be scarce on the NON-PREF side. PMID:27486394

  12. Asia: A Guide to Paperbacks. Revised Edition.

    ERIC Educational Resources Information Center

    Embree, Ainslie T., Ed.

    The guide includes in-print titles which were listed in the original guide and the supplement, new titles which appeared between December 1965 and December 1967, books published in 1968 provided by some publishers, and a few titles omitted from earlier editions. All the books are listed alphabetically by author within five subject areas:…

  13. ASIA A Guide to Paperbacks. Revised Edition.

    ERIC Educational Resources Information Center

    Embree, Ainslie T., Ed.

    The guide includes in-print titles which were listed in the original guide and the supplement, new titles which appeared between December 1965 and December 1967, books published in 1968 provided by some publishers, and a few titles omitted from earlier editions. All the books are listed alphabetically by author within five subject areas:…

  14. The threshold photoelectron spectrum of cyanovinylacetylene leads to an upward revision of the ionization energy

    NASA Astrophysics Data System (ADS)

    Holzmeier, Fabian; Lang, Melanie; Fischer, Ingo; Hemberger, Patrick

    2015-10-01

    Cyanovinylacetylene C5H3N was investigated by threshold photoelectron spectroscopy. The ionization energy (IE) was determined to be 10.04 eV. This value constitutes an upward revision of the earlier value of 9.33 eV. For both stereoisomers (trans and cis) computations predict very similar IEs and spectra. At 11.08 eV and 11.17 eV excited cationic states are observed. For the precursor 3-bromopyridine an IE of 9.34 eV was obtained. The appearance energy AE0K (3-bromopyridine, 3-pyridyl+) was determined to be 11.71 eV and a bond dissociation energy of the Csbnd Br bond in the 3-bromopyridine cation of 229 kJ mol-1 was derived.

  15. Standards for vision science libraries: 2014 revision

    PubMed Central

    Motte, Kristin; Caldwell, C. Brooke; Lamson, Karen S.; Ferimer, Suzanne; Nims, J. Chris

    2014-01-01

    Objective: This Association of Vision Science Librarians revision of the “Standards for Vision Science Libraries” aspires to provide benchmarks to address the needs for the services and resources of modern vision science libraries (academic, medical or hospital, pharmaceutical, and so on), which share a core mission, are varied by type, and are located throughout the world. Methods: Through multiple meeting discussions, member surveys, and a collaborative revision process, the standards have been updated for the first time in over a decade. Results: While the range of types of libraries supporting vision science services, education, and research is wide, all libraries, regardless of type, share core attributes, which the standards address. Conclusions: The current standards can and should be used to help develop new vision science libraries or to expand the growth of existing libraries, as well as to support vision science librarians in their work to better provide services and resources to their respective users. PMID:25349547

  16. Clean Air Act: Senate mulls revision bill

    SciTech Connect

    Fairley, P.

    1995-12-13

    Senator Lauch Faircloth (R., NC) has circulated a draft summary of possible revisions of the Clean Air Act (CAA). Chemical industry sources say the proposal would provide some regulatory relief but fear that supporting Faircloth could jeopardize their relationship with EPA. Faircloth`s proposal addresses various controversial aspect of CAA`s Title V permit program including the monitoring and permit modification provisions. The proposal would also define a facility`s {open_quotes}potential to emit,{close_quotes} upon which Title V permits are based. In the past year EPA has substantially revised its Title V program to address complaints from industry, the states, and Congress that the monitoring and modification provisions were too burdensome.

  17. Revision of ISO 15859 Aerospace Fluid Standards

    NASA Technical Reports Server (NTRS)

    Greene, Benjamin; McClure, Mark B.

    2012-01-01

    A detailed review of ISO 15859 "Space Systems - Fluid Characteristics, Sampling and Test Methods" was performed An approach to revising Parts 1-9 and 11-13 was developed and concurred by the NASA Technical Standards Program Office. The approach was to align them with the highest level source documents, and not to program-specific requirements. The updated documents were prepared and presented.

  18. Revised Unfilling Procedure for Solid Lithium Lenses

    SciTech Connect

    Leveling, A.; /Fermilab

    2003-06-03

    A procedure for unfilling used lithium lenses to has been described in Pbar Note 664. To date, the procedure has been used to disassemble lenses 20, 21, 17, 18, and 16. As a result of this work, some parts of the original procedure were found to be time consuming and ineffective. Modifications to the original procedure have been made to streamline the process and are discussed in this note. The revised procedure is included in this note.

  19. Heel pain-plantar fasciitis: revision 2014.

    PubMed

    Martin, Robroy L; Davenport, Todd E; Reischl, Stephen F; McPoil, Thomas G; Matheson, James W; Wukich, Dane K; McDonough, Christine M

    2014-11-01

    The Orthopaedic Section of the American Physical Therapy Association (APTA) has an ongoing effort to create evidence-based practice guidelines for orthopaedic physical therapy management of patients with musculoskeletal impairments described in the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). The purpose of these revised clinical practice guidelines is to review recent peer-reviewed literature and make recommendations related to nonarthritic heel pain.

  20. Coal within a revised energy perspective

    SciTech Connect

    Darmstadter, J.

    2006-07-15

    The author considers the use of coal within a revised energy perspective, focusing on the factors that will drive which fuels are used to generate electricity going forward. He looks at the world markets for fossil fuels and the difficulties of predicting oil and natural gas supply and prices, as demonstrated by the variability in projections from one year to another in the EIA's Annual Energy Outlook. 4 refs., 1 tab.