Evidence for an extraterrestrial impact 12,900 years ago that contributed to megafaunal extinctions and the Younger Dryas cooling

International Nuclear Information System (INIS)

Firestone, R.B.; West, A.; Kennett, J.P.; Becker, L.; Bunch, T.E.; Revay, Z.S.; Schultz, P.H.; Belgya, T.; Kennett, D.J.; Erlandson, J.M.; Dickenson, O.J.; Goodyear, A.C.; Harris, R.S.; Howard, G.A.; Kloosterman, J.B.; Lechler, P.; Mayewski, P.A.; Montgomery, J.; Porede, R.; Darrah, T.; Que Hee, S.S.; Smith, A.R.; Stich, A.; Topping, W.; Wittke, J.H.; Wolbach, W.S.

2007-01-01

A carbon-rich black layer, dating to ∼12.9 ka, has been previously identified at ∼50 Clovis-age sites across North America and appears contemporaneous with the abrupt onset of Younger Dryas (YD) cooling. The in situ bones of extinct Pleistocene megafauna and Clovistool assemblages occur below this black layer but not within or above it. Causes for the extinctions, the YD cooling, and the termination of Clovisculture have long been controversial. In this paper, we provide evidence for an extraterrestrial (ET) impact event at ?12.9 ka, which, we hypothesize, caused abrupt environmental changes that contributed to YD cooling, major ecological reorganization, broad-scale extinctions, and rapid human behavioral shifts at the end of the Clovis Period. Clovis-age sites in North American are overlain by a thin, discrete layer with varying peak abundances of: (1) magnetic grains with iridium, (2) magnetic microspherules (3) charcoal, (4) soot, (5) carbon spherules, (6) glass-like carbon, and (7) fullerenes with ET helium, all of which are evidence for an ET impact and associated biomass burning at ∼12.9 ka.This layer also extends throughout at least fifteen Carolina Bays, which are unique, elliptical wetlands, oriented to the northwest across the Atlantic Coastal Plain. We propose that one or more large, low-density ET objects exploded over northern North America, partially destabilizing the Laurentide Ice Sheet and triggering YD cooling. The shock wave, thermal pulse, and event-related environmental effects (e.g., extensive biomass burning, food limitations) contributed to the end-Pleistocene megafaunal extinctions and adaptive shifts among PaleoAmericans in North America

Younger Dryas sea level and meltwater pulse 1B recorded in Barbados reef crest coral Acropora palmata

Science.gov (United States)

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

2016-02-01

The Younger Dryas climate event occurred during the middle of the last deglacial cycle and is marked by an abrupt shift in the North Atlantic polar front almost to its former glacial position, trending east to west. Using high-precision and high-accuracy U-Th-dated Barbados reef crest coral, Acropora palmata, we generate a detailed sea level record from 13.9 to 9000 years before present (kyr B.P.) and reconstruct the ice volume response to the Younger Dryas cooling. From the mid-Allerød (13.9 kyr B.P.) to the end of the Younger Dryas (11.65 kyr B.P.), rates of sea level rise decreased smoothly from 20 mm yr-1 to 4 mm yr-1, culminating in a 400 year "slow stand" before accelerating into meltwater pulse 1B (MWP-1B). The MWP-1B event at Barbados is better constrained as beginning by 11.45 kyr B.P. and ending at 11.1 kyr B.P. during which time sea level rose 14 ± 2 m and rates of sea level rise reached 40 mm yr-1. We propose that MWP-1B is the direct albeit lagged response of the Northern Hemisphere ice sheets to the rapid warming marking the end of the Younger Dryas coinciding with rapid warming in the circum-North Atlantic region and the polar front shift from its zonal to meridional position 11.65 kyr B.P. As predicted by glaciological models, the ice sheet response to rapid North Atlantic warming was lagged by 400 years due to the thermal inertia of large ice sheets. The regional circum-North Atlantic Younger Dryas climate event is elevated to a global response through sea level changes, starting with the global slowdown in sea level rise during the Younger Dryas and culminating with MWP-1B. No meltwater pulses are evident at the initiation of the Younger Dryas climate event as is often speculated.

A Blind Test of the Younger Dryas Impact Hypothesis.

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Vance Holliday

Full Text Available The Younger Dryas Impact Hypothesis (YDIH states that North America was devastated by some sort of extraterrestrial event ~12,800 calendar years before present. Two fundamental questions persist in the debate over the YDIH: Can the results of analyses for purported impact indicators be reproduced? And are the indicators unique to the lower YD boundary (YDB, i.e., ~12.8k cal yrs BP? A test reported here presents the results of analyses that address these questions. Two different labs analyzed identical splits of samples collected at, above, and below the ~12.8ka zone at the Lubbock Lake archaeological site (LL in northwest Texas. Both labs reported similar variation in levels of magnetic micrograins (>300 mg/kg >12.8ka and <11.5ka, but <150 mg/kg 12.8ka to 11.5ka. Analysis for magnetic microspheres in one split, reported elsewhere, produced very low to nonexistent levels throughout the section. In the other split, reported here, the levels of magnetic microspherules and nanodiamonds are low or nonexistent at, below, and above the YDB with the notable exception of a sample <11,500 cal years old. In that sample the claimed impact proxies were recovered at abundances two to four orders of magnitude above that from the other samples. Reproducibility of at least some analyses are problematic. In particular, no standard criteria exist for identification of magnetic spheres. Moreover, the purported impact proxies are not unique to the YDB.

Rapid response of alpine timberline vegetation to the Younger Dryas climate oscillation in the Colorado Rocky Mountains, USA

International Nuclear Information System (INIS)

Reasoner, M.A.; Jodry, M.A.

2000-01-01

Paleobotanical records from two high-altitude (>3,300 m) sites in Colorado show a clear and immediate response to the Younger Dryas climate oscillation. The Black Mountain Lake and Sky Pond records indicate that alpine timberline migrated upslope to near-modern elevations during the late Bolling-Allerod (13.6--12.9 ka). Subsequent declines in arboreal pollen percentages and accumulation rates during the Younger Dryas interval (12.9--11.7 ka) reflect a downslope displacement of the alpine timberline ecotone of 60--120 m in elevation. This change translates to a cooling of summer temperature by ∼0.4--0.9 C and is consistent with proposed Younger Dryas advances of alpine glaciers in the Rocky Mountains to positions close to Little Ice Age maxima. Alpine timberline readvanced upslope to elevations above both sites between 11.7 and 11.4 ka. The concomitant response of temperature-sensitive alpine timberline vegetation in Colorado and late-glacial changes in North Atlantic thermohaline circulating implicates a rapid, widespread atmospheric transmission of the Younger Dryas climate oscillation

Rapid response of alpine timberline vegetation to the Younger Dryas climate oscillation in the Colorado Rocky Mountains, USA

Energy Technology Data Exchange (ETDEWEB)

Reasoner, M.A.; Jodry, M.A.

2000-01-01

Paleobotanical records from two high-altitude (>3,300 m) sites in Colorado show a clear and immediate response to the Younger Dryas climate oscillation. The Black Mountain Lake and Sky Pond records indicate that alpine timberline migrated upslope to near-modern elevations during the late Bolling-Allerod (13.6--12.9 ka). Subsequent declines in arboreal pollen percentages and accumulation rates during the Younger Dryas interval (12.9--11.7 ka) reflect a downslope displacement of the alpine timberline ecotone of 60--120 m in elevation. This change translates to a cooling of summer temperature by {approximately}0.4--0.9 C and is consistent with proposed Younger Dryas advances of alpine glaciers in the Rocky Mountains to positions close to Little Ice Age maxima. Alpine timberline readvanced upslope to elevations above both sites between 11.7 and 11.4 ka. The concomitant response of temperature-sensitive alpine timberline vegetation in Colorado and late-glacial changes in North Atlantic thermohaline circulating implicates a rapid, widespread atmospheric transmission of the Younger Dryas climate oscillation.

Identification of contrasting seasonal sea ice conditions during the Younger Dryas

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Cabedo-Sanz, P.; Belt, S. T.; Knies, J.

2012-12-01

The presence of the sea ice diatom biomarker IP25 in Arctic marine sediments has been used in previous studies as a proxy for past spring sea ice occurrence and as an indicator of wider palaeoenvironmental conditions for different regions of the Arctic over various timescales [e.g. 1, 2]. The current study focuses on high-resolution palaeo sea ice reconstructions for northern Norway during the last ca. 15 cal. kyr BP. Within this study, particular emphasis has been placed on the identification of the sea ice conditions during the Younger Dryas and the application of different biomarker-based proxies to both identify and quantify seasonal sea ice conditions. Firstly, the appearance of the specific sea ice diatom proxy IP25 at ca. 12.9 cal. kyr BP in a marine sediment core (JM99-1200) obtained from Andfjorden has provided an unambiguous but qualitative measure of seasonal sea ice and thus the onset of the Younger Dryas stadial. The near continuous occurrence of IP25 for the next ca. 1400 yr demonstrates seasonal sea ice during this interval, although variable abundances suggest that the recurrent conditions in the early-mid Younger Dryas (ca. 12.9 - 11.9 cal. kyr BP) changed significantly from stable to highly variable sea ice conditions at ca. 11.9 cal. kyr BP and this instability in sea ice prevailed for the subsequent ca. 400 yr. At ca. 11.5 cal. kyr BP, IP25 disappeared from the record indicating ice-free conditions that signified the beginning of the Holocene. Similarly, a high resolution record from the Kveithola Through, western Barents Sea, showed clearly higher IP25 concentrations during the Younger Dryas stadial compared to the Holocene. For both marine records, the IP25 concentrations were also combined with those of the open water phytoplankton biomarker brassicasterol to generate PBIP25 data from which more quantitative measurements of sea ice were determined. The contrasting seasonal sea ice conditions during the Younger Dryas were further verified

The Younger Dryas phase of Great Salt Lake, Utah, USA

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Oviatt, Charles G.; Miller, D.M.; McGeehin, J.P.; Zachary, C.; Mahan, S.

2005-01-01

Field investigations at the Public Shooting Grounds (a wildlife-management area on the northeastern shore of Great Salt Lake) and radiocarbon dating show that the Great Salt Lake rose to the Gilbert shoreline sometime between 12.9 and 11.2 cal ka. We interpret a ripple-laminated sand unit exposed at the Public Shooting Grounds, and dated to this time interval, as the nearshore sediments of Great Salt Lake deposited during the formation of the Gilbert shoreline. The ripple-laminated sand is overlain by channel-fill deposits that overlap in age (11.9-11.2 cal ka) with the sand, and by wetland deposits (11.1 to 10.5 cal ka). Consistent accelerator mass spectrometry radiocarbon ages were obtained from samples of plant fragments, including those of emergent aquatic plants, but mollusk shells from spring and marsh deposits yielded anomalously old ages, probably because of a variable radiocarbon reservoir effect. The Bonneville basin was effectively wet during at least part of the Younger Dryas global-cooling interval, however, conflicting results from some Great Basin locations and proxy records indicate that the regional effects of Younger Dryas cooling are still not well understood. ?? 2005 Elsevier B.V. All rights reserved.

Lateglacial landscape and vegetation change and the younger dryas climatic oscillation in New Zealand

Science.gov (United States)

McGlone, M. S.

Lateglacial sequences in New Zealand show progressive afforestation and landscape stabilization reflecting a warming climate. Between 14,500 BP and 11,500 BP, afforestation and landscape stability was achieved throughout most of the North Island and the northwest sector of the South Island. In the South Island, scrub and tree ferns were replacing previous grasslands in the east by 11,000 BP, and broadleaved forest was spreading in the west. No significant reversals of these trends occurred and afforestation was complete by 9500 BP. Glaciers of the high central part of the Southern Alps made a series of advances between 14,000 and 9000 BP Most of these advances are poorly dated but two moraines are of Younger Dryas age. Glacial advances in the face of the general Lateglacial warming trend may have been driven by stronger westerly winds increasing snowfall on high altitude névés, and by reduced ablation as a consequence of moist, cloudy, low insolation summers. The cause of the northern hemisphere Younger Dryas cooling is still uncertain, and expected Southern Hemisphere responses may differ according to the mechanism proposed for the cooling. Poor chronological resolution and apparent conflict between the various types of evidence for climatic change make detection of an unambiguous Younger Dryas in New Zealand problematical.

Late Pleistocene Megafaunal Extinction Consistent With YDB Impact Hypothesis at Younger Dryas Onset

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Kennett, J. P.; Kennett, D. J.

2008-12-01

At least 35 mammal and 19 bird genera became extinct across North America near the end of the Pleistocene. Modern increases in stratigraphic and dating resolution suggest that this extinction occurred relatively rapidly near 12.9 ka (11 radiocarbon kyrs). Within the context of a long-standing debate about its cause, Firestone et al., (2007) proposed that this extinction resulted from an extraterrestrial (ET) impact over North America at 12.9 ka. This hypothesis predicts that the extinction of most of these animals should have occurred abruptly at 12.9 ka. To test this hypothesis, we have critically examined radiocarbon ages and the extinction stratigraphy of these taxa. From a large data pool, we selected only radiocarbon dates with low error margins with a preference for directly dated biological materials (e.g., bone, dung, etc.) and modern chemical purification techniques. A relatively small number of acceptable dates indicate that at least 16 animal genera and several other species became extinct close to 12.9 ka. These taxa include the most common animals of the late Pleistocene such as horses, camels, and mammoths. Also, the remains of extinct taxa are reportedly found up to, but not above, the base of a widely distributed carbon-rich layer called the black mat. This stratum forms an abrupt, major biostratigraphic boundary at the Younger Dryas onset (12.9 ka), which also contains multiple ET markers comprising the impact layer (the YDB). Surviving animal populations were abruptly reduced at the YDB (e.g., Bison), with major range restrictions and apparent evolutionary bottlenecks. The abruptness of this major extinction is inconsistent with the hypotheses of human overkill and climatic change. We argue that extinction ages older than 12.9 ka for many less common species result from the Signor-Lipps effect, but the impact hypothesis predicts that as new dates are acquired, they will approach ever closer to 12.9 ka. The megafaunal extinction is strongly

Bayesian chronological analyses consistent with synchronous age of 12,835-12,735 Cal B.P. for Younger Dryas boundary on four continents

DEFF Research Database (Denmark)

Kennett, James P.; Kennett, Douglas J.; Culleton, Brendan J.

2015-01-01

The Younger Dryas impact hypothesis posits that a cosmic impact across much of the Northern Hemisphere deposited the Younger Dryas boundary (YDB) layer, containing peak abundances in a variable assemblage of proxies, including magnetic and glassy impact-related spherules, high-temperature mineral...

Atlantic Warm Pool Trigger for the Younger Dryas Climate Event

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

2011-12-01

There is growing evidence that variability in the size and heat content of the tropical Atlantic Warm Pool impacts circum-North Atlantic climate via the Atlantic Multi-decadal Oscillation mode (Wang et al., 2008). The Atlantic Warm Pool spans the Gulf of Mexico, Caribbean Sea and the western tropical North Atlantic. Barbados is located near the center of the tropical Atlantic Warm Pool and coupled ocean models suggest that Barbados remains near the center of the tropical Atlantic Warm Pool under varying wind stress simulations. Measurements of the oxygen isotope paleothermometer in Acropora palmata coral species recovered from cores offshore Barbados, show a 3oC monotonic decrease in sea surface temperature from 13106 ± 83 to 12744 ± 61 years before present (errors given as 2 sigma). This interval corresponds to a sea level rise from 71.4 meters to 67.1 meters below present levels at Barbados. The 3oC temperature decrease is captured in eight A. palmata specimens that are in stratigraphic sequence, 230Th/234U dated, and analyzed for oxygen isotopes. All measurements are replicated. We are confident that this is the warm pool equivalent of the Younger Dryas climate event. The initiation of this temperature drop in the Atlantic Warm Pool predates the Younger Dryas start in Greenland ice cores, reported to start at 12896 ± 138 years (relative to AD 2000) (Rasmussen et al., 2006), while few other Younger Dryas climate records are dated with similar accuracy to make the comparison. Rasmussen, S.O., Andersen, K.K., Svensson, A.M., Steffensen, J.P., Vinther, B.M., Clausen, H.B., Siggaard-Andersen, M.L., Johnsen, S.J., Larsen, L.B., Dahl-Jensen, D., Bigler, M., Röthlisberger, R., Fischer, H., Goto-Azuma, K., Hansson, M.E., and Ruth, U., 2006, A new Greenland ice core chronology for the last glacial termination: J. Geophys. Res., v. 111, p. D06102. Wang, C., Lee, S.-K., and Enfield, D.B., 2008, Atlantic Warm Pool acting as a link between Atlantic Multidecadal

Reduced solar activity as a trigger for the start of the Younger Dryas?

NARCIS (Netherlands)

Renssen, H; van Geel, B; van der Plicht, J; Magny, M

2000-01-01

It is generally assumed that changes in ocean circulation forced the abrupt climate changes during the Late Pleistocene, including the Younger Dryas event. Recently, however, it was proposed that variations in solar irradiance could have played a much more prominent role in forcing Pleistocene

Minimal geological methane emissions during the Younger Dryas-Preboreal abrupt warming event.

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Petrenko, Vasilii V; Smith, Andrew M; Schaefer, Hinrich; Riedel, Katja; Brook, Edward; Baggenstos, Daniel; Harth, Christina; Hua, Quan; Buizert, Christo; Schilt, Adrian; Fain, Xavier; Mitchell, Logan; Bauska, Thomas; Orsi, Anais; Weiss, Ray F; Severinghaus, Jeffrey P

2017-08-23

Methane (CH 4 ) is a powerful greenhouse gas and plays a key part in global atmospheric chemistry. Natural geological emissions (fossil methane vented naturally from marine and terrestrial seeps and mud volcanoes) are thought to contribute around 52 teragrams of methane per year to the global methane source, about 10 per cent of the total, but both bottom-up methods (measuring emissions) and top-down approaches (measuring atmospheric mole fractions and isotopes) for constraining these geological emissions have been associated with large uncertainties. Here we use ice core measurements to quantify the absolute amount of radiocarbon-containing methane ( 14 CH 4 ) in the past atmosphere and show that geological methane emissions were no higher than 15.4 teragrams per year (95 per cent confidence), averaged over the abrupt warming event that occurred between the Younger Dryas and Preboreal intervals, approximately 11,600 years ago. Assuming that past geological methane emissions were no lower than today, our results indicate that current estimates of today's natural geological methane emissions (about 52 teragrams per year) are too high and, by extension, that current estimates of anthropogenic fossil methane emissions are too low. Our results also improve on and confirm earlier findings that the rapid increase of about 50 per cent in mole fraction of atmospheric methane at the Younger Dryas-Preboreal event was driven by contemporaneous methane from sources such as wetlands; our findings constrain the contribution from old carbon reservoirs (marine methane hydrates, permafrost and methane trapped under ice) to 19 per cent or less (95 per cent confidence). To the extent that the characteristics of the most recent deglaciation and the Younger Dryas-Preboreal warming are comparable to those of the current anthropogenic warming, our measurements suggest that large future atmospheric releases of methane from old carbon sources are unlikely to occur.

Minimal geological methane emissions during the Younger Dryas-Preboreal abrupt warming event

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Petrenko, Vasilii V.; Smith, Andrew M.; Schaefer, Hinrich; Riedel, Katja; Brook, Edward; Baggenstos, Daniel; Harth, Christina; Hua, Quan; Buizert, Christo; Schilt, Adrian; Fain, Xavier; Mitchell, Logan; Bauska, Thomas; Orsi, Anais; Weiss, Ray F.; Severinghaus, Jeffrey P.

2017-08-01

Methane (CH4) is a powerful greenhouse gas and plays a key part in global atmospheric chemistry. Natural geological emissions (fossil methane vented naturally from marine and terrestrial seeps and mud volcanoes) are thought to contribute around 52 teragrams of methane per year to the global methane source, about 10 per cent of the total, but both bottom-up methods (measuring emissions) and top-down approaches (measuring atmospheric mole fractions and isotopes) for constraining these geological emissions have been associated with large uncertainties. Here we use ice core measurements to quantify the absolute amount of radiocarbon-containing methane (14CH4) in the past atmosphere and show that geological methane emissions were no higher than 15.4 teragrams per year (95 per cent confidence), averaged over the abrupt warming event that occurred between the Younger Dryas and Preboreal intervals, approximately 11,600 years ago. Assuming that past geological methane emissions were no lower than today, our results indicate that current estimates of today’s natural geological methane emissions (about 52 teragrams per year) are too high and, by extension, that current estimates of anthropogenic fossil methane emissions are too low. Our results also improve on and confirm earlier findings that the rapid increase of about 50 per cent in mole fraction of atmospheric methane at the Younger Dryas-Preboreal event was driven by contemporaneous methane from sources such as wetlands; our findings constrain the contribution from old carbon reservoirs (marine methane hydrates, permafrost and methane trapped under ice) to 19 per cent or less (95 per cent confidence). To the extent that the characteristics of the most recent deglaciation and the Younger Dryas-Preboreal warming are comparable to those of the current anthropogenic warming, our measurements suggest that large future atmospheric releases of methane from old carbon sources are unlikely to occur.

The Younger Dryas impact hypothesis: A requiem

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Pinter, Nicholas; Scott, Andrew C.; Daulton, Tyrone L.; Podoll, Andrew; Koeberl, Christian; Anderson, R. Scott; Ishman, Scott E.

2011-06-01

The Younger Dryas (YD) impact hypothesis is a recent theory that suggests that a cometary or meteoritic body or bodies hit and/or exploded over North America 12,900 years ago, causing the YD climate episode, extinction of Pleistocene megafauna, demise of the Clovis archeological culture, and a range of other effects. Since gaining widespread attention in 2007, substantial research has focused on testing the 12 main signatures presented as evidence of a catastrophic extraterrestrial event 12,900 years ago. Here we present a review of the impact hypothesis, including its evolution and current variants, and of efforts to test and corroborate the hypothesis. The physical evidence interpreted as signatures of an impact event can be separated into two groups. The first group consists of evidence that has been largely rejected by the scientific community and is no longer in widespread discussion, including: particle tracks in archeological chert; magnetic nodules in Pleistocene bones; impact origin of the Carolina Bays; and elevated concentrations of radioactivity, iridium, and fullerenes enriched in 3He. The second group consists of evidence that has been active in recent research and discussions: carbon spheres and elongates, magnetic grains and magnetic spherules, byproducts of catastrophic wildfire, and nanodiamonds. Over time, however, these signatures have also seen contrary evidence rather than support. Recent studies have shown that carbon spheres and elongates do not represent extraterrestrial carbon nor impact-induced megafires, but are indistinguishable from fungal sclerotia and arthropod fecal material that are a small but common component of many terrestrial deposits. Magnetic grains and spherules are heterogeneously distributed in sediments, but reported measurements of unique peaks in concentrations at the YD onset have yet to be reproduced. The magnetic grains are certainly just iron-rich detrital grains, whereas reported YD magnetic spherules are

The response of southern California ecosystems to Younger Dryas-like rapid climate change: Comparison of glacial terminations 1 and 5.

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Heusser, L. E.; Hendy, I. L.

2015-12-01

The Younger Dryas is a well-known rapid climatic cooling that interrupted the Marine Isotope Stage (MIS) 1-2 deglacial warming of Termination 1. This cool event has been associated with ice sheet readvance, meridional overturning, circulation changes, and southward movement of the Intertropical Convergence Zone. In Southern California, the Younger Dryas has been associated with cooler SST, low marine productivity, a well-ventilated oxygen minimum zone, and a wetter climate. Similar rapid cooling events have been found at other terminations including Termination 5 at the MIS 11-12 deglaciation (~425 Ka) identified by ice rafting events in the North Atlantic. Here we present new pollen census data from a unique suite of cores taken from the sub-oxic sediments of Santa Barbara Basin (MV0508-15JC, MV0805-20JC, MV0508-33JC, 29JC and 21JC). These short cores, collected on a truncated anticline within SBB, provide the opportunity to examine the response of southern California terrestrial and marine ecosystems to rapid climate change during the MIS 11-12 deglaciation (Termination 5), which is identified by a bioturbated interval within a sequence of laminated sediments. During Termination 1, changes in Southern California precipitation are reflected in pollen- based reconstructions Southern California vegetation. The high precipitation of glacial montane-coniferous assemblages of pine (Pinus) and Juniper (Juniperus/Calocedrus) transitions into interglacial drought, as expresssed by arid oak (Quercus)/chaparral vegetation. The Younger Dryas interrupts the transition as a high-amplitude pulse in pine associated with increased Gramineae (grass). Termination 5 differs, as the high precipitation of glacial montane-coniferous assemblages do not transition into arid oak/chaparral vegetation. However, a Younger Dryas-like rapid climate event was associated with increased pine and grass.

Reply to Ives and Froese: Regarding the impact-related Younger Dryas boundary layer at Chobot site, Alberta, Canada

Czech Academy of Sciences Publication Activity Database

Wittke, J. H.; Bunch, T. E.; Tankersley, K. B.; Daniel Jr., I. R.; Kloosterman, J. B.; Kletetschka, Günther; West, A.; Firestone, R. B.

2013-01-01

Roč. 110, č. 41 (2013), E3900-E3900 ISSN 0027-8424 Institutional support: RVO:67985831 Keywords : Younger Dryas boundary * charcoal * black mat Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 9.809, year: 2013

Younger Dryas cooling and the Greenland climate response to CO2.

Science.gov (United States)

Liu, Zhengyu; Carlson, Anders E; He, Feng; Brady, Esther C; Otto-Bliesner, Bette L; Briegleb, Bruce P; Wehrenberg, Mark; Clark, Peter U; Wu, Shu; Cheng, Jun; Zhang, Jiaxu; Noone, David; Zhu, Jiang

2012-07-10

Greenland ice-core δ(18)O-temperature reconstructions suggest a dramatic cooling during the Younger Dryas (YD; 12.9-11.7 ka), with temperatures being as cold as the earlier Oldest Dryas (OD; 18.0-14.6 ka) despite an approximately 50 ppm rise in atmospheric CO(2). Such YD cooling implies a muted Greenland climate response to atmospheric CO(2), contrary to physical predictions of an enhanced high-latitude response to future increases in CO(2). Here we show that North Atlantic sea surface temperature reconstructions as well as transient climate model simulations suggest that the YD over Greenland should be substantially warmer than the OD by approximately 5 °C in response to increased atmospheric CO(2). Additional experiments with an isotope-enabled model suggest that the apparent YD temperature reconstruction derived from the ice-core δ(18)O record is likely an artifact of an altered temperature-δ(18)O relationship due to changing deglacial atmospheric circulation. Our results thus suggest that Greenland climate was warmer during the YD relative to the OD in response to rising atmospheric CO(2), consistent with sea surface temperature reconstructions and physical predictions, and has a sensitivity approximately twice that found in climate models for current climate due to an enhanced albedo feedback during the last deglaciation.

Microspherules in the Sediment from the Onset of Younger Dryas; Airburst and/or Volcanic Explosion

Czech Academy of Sciences Publication Activity Database

Kletetschka, Günther; Hrubá, J.; Nábělek, Ladislav; West, A.; Vondrák, D.; Stuchlík, Evžen; Kadlec, Jaroslav; Procházka, V.

2017-01-01

Roč. 52, SI 1 (2017), A169 ISSN 1086-9379. [Annual Meeting of the Meteoritical Society /80./. 23.07.2017-28.07.2017, Santa Fe] R&D Projects: GA ČR(CZ) GA17-05935S Institutional support: RVO:67985831 ; RVO:60077344 ; RVO:67985530 Keywords : microspherules * volcanic explosion * Younger Dryas * sediments Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics; DA - Hydrology ; Limnology (BC-A) http://onlinelibrary.wiley.com/doi/10.1111/maps.2017.52.issue-S1/issuetoc

Spatial variability and trends in Younger Dryas equilibrium line altitudes across the European Alps using a hypsometrically based ELA model: results and implications

Science.gov (United States)

Keeler, D. G.; Rupper, S.; Schaefer, J. M.; Finkel, R. C.; Maurer, J. M.

2016-12-01

Alpine glaciers constitute an important component of terrestrial paleoclimate records due to, among other characteristics, their high sensitivity to climate change, near global extent, and their integration of myriad climate variables into a single, easily detected signal. Because the glacier equilibrium line altitude (ELA) provides a more explicit representation of climate than many other glacier properties, ELA methods allow for more direct comparisons of multiple glaciers within or between regions. Such comparisons allow for more complete investigations of the ultimate causes of mountain glaciation during specific events. Many studies however tend to focus on a limited number of sites, and employ a large variety of different techniques for ELA reconstruction between studies, making wider climate implications more tenuous. Methods of ELA reconstruction that can be rapidly and consistently applied to an arbitrary number of paleo-glaciers would provide a more accurate portrayal of the changes in climate across a given region. Here we present ELA reconstructions from Egesen Stadial moraines across the European Alps using an ELA model accounting for differences in glacier width, glacier shape, bed topography, ice thickness, and glacier length, including several glaciers constrained to the Younger Dryas using surface exposure dating techniques. We compare reconstructed Younger Dryas ELA values to modern ELA values using the same model, or using end of summer snowline estimates where no glacier is currently present. We further provide uncertainty estimates on the ΔELA using bootstrapped Monte Carlo simulations for the various input parameters. Preliminary results compare favorably to previous glacier studies of the European Younger Dryas, but provide greater context from many glaciers across the region as a whole. Such results allow for a more thorough investigation of the spatial variability and trends in climate during the Younger Dryas across the European Alps, and

Carbon isotopes from fossil packrat pellets and elevational movements of Utah agave plants reveal the Younger Dryas cold period in Grand Canyon, Arizona

Science.gov (United States)

Cole, K.L.; Arundel, S.T.

2005-01-01

Carbon isotopes in rodent fecal pellets were measured on packrat (Neotoma spp.) middens from the Grand Canyon, Arizona. The pellet samples reflect the abundance of cold-intolerant C4 and Crassulacean acid metabolism (CAM) plant species relative to the predominant C3 vegetation in the packrat diet. The temporal sequence of isotopic results suggests a temperature decline followed by a sharp increase corresponding to the B??lling/Aller??d-Younger Dryas - early Holocene sequence. This pattern was then tested using the past distribution of Utah agave (Agave utahensis). Spatial analyses of the range of this temperature-sensitive CAM species demonstrate that its upper elevational limit is controlled by winter minimum temperature. Applying this paleotemperature proxy to the past elevational limits of Utah agave suggests that minimum winter temperatures were ???8??C below modern values during the Last Glacial Maximum, 4.5-6.5 ??C below modern during the B??lling/Aller??d, and 7.5-8.7 ??C below modern during the early Younger Dryas. As the Younger Dryas terminated, temperatures warmed ???4 ??C between ca. 11.8 ka and 11.5 ka. These extreme fluctuations in winter minimum temperature have not been generally accepted for terrestrial paleoecological records from the arid southwestern United States, likely because of large statistical uncertainties of older radiocarbon results and reliance on proxies for summer temperatures, which were less affected. ?? 2005 Geological Society of America.

The impact of climate and environmental processes on vegetation pattern in the Czechowskie lake catchment Czechowo Region (Northern Tuchola Pinewoods) during the Younger Dryas cooling

Science.gov (United States)

Noryśkiewicz, Agnieszka Maria; Kramkowski, Mateusz; Słowiński, Michał; Zawiska, Izabela; Lutyńska, Monika; Błaszkiewicz, Mirosław; Brauer, Achim

2014-05-01

Czechowskie lake is located in the northern part of the Tuchola Pinewoods District (Northern Poland) in a young glacial landscape. At present, the majority of the area is forested or used for agricultural purposes, but among them a high amount of basins filled with biogenic sediments are present. This area is very suitable for the postglacial vegetation development investigation because of the LST ash and laminated sediments which we found in the Trzechowskie palaeolake and Czechowskie Lake (Wulf et. all 2013). The aim of the research was to reconstruct the past landscape and vegetation response to Younger Dryas cooling and we present the results of the palinological analysis done for 6 core of biogenic sediments. Our main objective was to determine whether local factors such as topography and soil cover have a significant impact on the vegetation, eutrophy and sedimentation rate at this time. In the lake Czechowskie lake catchment we have six cores that cover postglacial succession (Lake Czechowskie small basin - profile JC-12-s; Lake Czechowskiego terrace - profile TK; Lake Czechowskie vicinity - profile "Oko and Cz/80; Trzechowskie paleolake - profile T/trz; Valley between paleolake Trzechowskie and Lake Czechowskie - profile DTCZ-4). The paleoecological research carried out involved an analysis of pollen, macrofossils, Cladocera, diatom, loss-on-ignition and CaCO3 content. The results show, that the dominant plant communities during the Youngers Dryas in the region nearby Lake Czechowskie are heliophytes xeric herb vegetation with juniper (Juniperus communis) shrubs and birch (Betula) and pine (Pinus sylvestris). In the pollen diagrams there was the difference noted in the participation of the dominant pollen, the juniper pollen was always high but varied from 18 to 37%, birch average pollen share was between 17-27%. The thickness and type of the sediment accumulated in Younger Dryas in the presented profiles differs significantly. In the profiles which

A new concept for paleohydrological evolution of the Younger Dryas in NE Brazil

Science.gov (United States)

Bouimetarhan, Ilham; Prange, Matthias; Gonzalez, Catalina; Dupont, Lydie

2016-04-01

The late deglacial interval from approximately 13 to 11 kyr BP contains some of the best documented abrupt climate changes in the Past, the Younger Dryas (YD). It is also an interval when the bipolar climatic signature of millennial-scale changes in the Atlantic meridional overturning circulation (AMOC) is well expressed. Here we present a high-resolution palynological record from core GeoB16205-4 (1°21.11'N, 43°05.80'W), retrieved off the Parnaíba River mouth, southeast of the Amazon River (~1955 m water depth). Pollen and organic-walled dinoflagellate cyst assemblages indicate a predominantly wet climate during the YD in the nowadays semi-arid Nordeste, whereby a second phase between ~12.3 and 11.7 kyr BP is wetter than the period before. This is recorded by a strong increase in the concentrations of river plume dinoflagellate cyst assemblages indicative of a stratified surface water column and reduced salinity environments, as well as a drop in grass pollen and microcharcoal particle concentrations along with strong fluctuations in the representation of rain forest, gallery forest and tree ferns suggesting year-round humid conditions. This shift from a relatively wet first phase to a much wetter second phase is in agreement with the transient TRACE-21k coupled climate model simulation which shows a first pluvial Parnaíba stage from ~12.8 to 12.3 kyr BP and a second stronger pluvial stage between ~12.3 and 11.7 kyr BP to be related to a very weak AMOC due to meltwater pulses in the North Atlantic. The AMOC variation induces a steep temperature gradient between the Southern and the Northern Hemisphere which forces a southward shift of the Intertropical Convergence Zone (ITCZ) and its associated rainfall. The two-step hydroclimatic and environmental evolution during the Younger Dryas has not been documented previously in this region.

A Younger Dryas re-advance of local glaciers in north Greenland

DEFF Research Database (Denmark)

Larsen, Nicolaj K.; Funder, Svend; Linge, Henriette

2016-01-01

The Younger Dryas (YD) is a well-constrained cold event from 12,900 to 11,700 years ago but it remains unclear how the cooling and subsequent abrupt warming recorded in ice cores was translated into ice margin fluctuations in Greenland. Here we present 10Be surface exposure ages from three moraines...... in front of local glaciers on a 50 km stretch along the north coast of Greenland, facing the Arctic Ocean. Ten ages range from 11.6 ± 0.5 to 27.2 ± 0.9 ka with a mean age of 12.5 ± 0.7 ka after exclusion of two outliers. We consider this to be a minimum age for the abandonment of the moraines. The ages...... the interval 11.8-13.0 ka ago. This is the first time a synchronous YD glacier advance and subsequent retreat has been recorded for several independent glaciers in Greenland. In most other areas, there is no evidence for re-advance and glaciers were retreating during YD. We explain the different behaviour...

Extraordinary Biomass-Burning Episode and Impact Winter Triggered by the Younger Dryas Cosmic Impact approximate to 12,800 Years Ago. 1. Ice Cores and Glaciers

Czech Academy of Sciences Publication Activity Database

Wolbach, W. S.; Ballard, J. P.; Mayewski, P. A.; Adedeji, V.; Bunch, T. E.; Firestone, R. B.; French, T. A.; Howard, G. A.; Israde-Alcántara, I.; Johnson, J. R.; Kimbel, D. R.; Kinzie, Ch. R.; Kurbatov, A.; Kletetschka, Günther; LeCompte, M. A.; Mahaney, W. C.; Mellot, A. L.; Maiorana-Boutilier, A.; Mitra, S.; Moore, Ch. R.; Napier, W. M.; Parlier, J.; Tankersley, K. B.; Thomas, B. C.; Wittke, J. H.; West, A.; Kennett, J. P.

2018-01-01

Roč. 126, č. 2 (2018), s. 165-184 ISSN 0022-1376 Institutional support: RVO:67985831 Keywords : biomass burning * comet * deposition * ice core * impact * mass extinction * paleoclimate * paleoenvironment * platinum * trigger mechanism * wildfire * winter * Younger Dryas Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 1.952, year: 2016

Post-Younger Dryas climate interval linked to circumpolar vortex variability: isotopic evidence from Fayetteville Green Lake, New York

Science.gov (United States)

Kirby, M. E.; Patterson, W. P.; Mullins, H. T.; Burnett, A. W.

2002-04-01

The late-Glacial/Holocene transition in the North Atlantic-European sectors has long been known to be a period of rapid climate change. There is, however, a continued need for acquiring and developing paleoclimate archives spanning this interval from continental settings. Here we report on a lacustrine (Fayetteville Green Lake) isotope record sampled at a 10-year resolution from the NE USA over the late-Glacial/Holocene interval (14,600-8000 cal year BP). Based on prior isotopic and hydrologic research from Green Lake, the δ18O(calcite) values predominantly reflect winter moisture source and thus winter atmospheric patterns. Furthermore, we use historic (AD 1948-1980) winter circulation data and δ18O(calcite) values from varved sediments to examine the relationship between the circumpolar vortex latitude and isotopes which results in a strong (r = -0.79 r2 = 0.63) negative relationship. Using the linear regression from the isotope-vortex relationship, we model the winter vortex latitude for the late-Glacial/Holocene transition over the NE USA. In addition, we identify an interval from 11,600 to 10,300 cal year BP (the post-Younger Dryas climate interval) wherein the mean winter vortex over the NE USA was expanded by 6° latitude ( 36.1°N i.e., 630 km) from its mean historic position between AD 1948-1998 ( 41.8°N). Renewal of more vigorous thermohaline circulation following the Younger Dryas cold event may have forced the post-Younger Dryas climate interval. Increased poleward heat transport due to an active oceanic conveyor would have strengthened the thermal contrast between the NE USA and the North Atlantic thereby enhancing atmospheric pressure gradients and firmly establishing the semi-permanent winter trough over the NE USA. Consequently, storms tracked more frequently up the east coast of the United States from the Gulf of Mexico and Atlantic regions delivering precipitation with relatively high δ18O values to the NE USA. Alternatively, the relative

Quartz microstructures in the Younger Dryas boundary layer ~12.9 ka.

Science.gov (United States)

van Hoesel, A.; Hoek, W. Z.; Pennock, G. M.; Drury, M. R.

2012-04-01

In 2007, Firestone et al. proposed that an extraterrestrial impact occurred at the end of the Allerød interstadial, destabilizing the North American ice sheet and initiating the colder Younger Dryas (YD) stadial. Up to now, the evidence for this proposed impact has been heavily debated (Pinter et al., 2011) and no one has been able to provide convincing evidence in favour of the hypothesis. Two years later, Mahaney et al. (2009) claimed that they had frequently found planar deformation features (PDFs) in quartz from a possible YD boundary layer in Venezuela. However, the data presented consisted of an SEM image of the surface of a quartz grain only, and in following work Mahaney et al. (2010) stated that they had found no irrefutable evidence of PDFs. Instead, they showed grains with oriented cracks along their edges, which they claimed to be related to the 'mass impact and extreme heat' from incoming ejecta material. However, oriented cracks are not accepted evidence for an impact (French, Koeberl, 2010). We investigate the quartz fraction of samples from the European Usselo horizon, an Allerød-YD age soil, as well as one sample from the North American Black Mat, which marks the onset of the YD. Possible shocked quartz grains were isolated using density separation, mounted in epoxy and polished. No evidence for oriented cracks along grain edges, like those reported by Mahaney et al. (2010), has been found so far. Transmitted light microscopy showed that a number of grains contained tectonic deformation lamellae. One grain from the Usselo horizon contains at least two sets of closely spaced, straight, and narrow lamellae, similar to PDFs. In SEM-CL imaging however, only some of these lamellae showed up as non-luminescent, while most had the same intensity as the host grain. This is not typical for PDFs (Hamers, Drury 2011). It is possible that these lamellae represent planar fractures, which also form by low pressure shock processes. It must be noted that even if

Extraordinary Biomass-Burning Episode and Impact Winter Triggered by the Younger Dryas Cosmic Impact approximate to 12,800 Years Ago. 2. Lake, Marine, and Terrestrial Sediments

Czech Academy of Sciences Publication Activity Database

Wolbach, W. S.; Ballard, J. P.; Mayewski, P. A.; Parnell, A. C.; Cahill, N.; Adedeji, V.; Bunch, T. E.; Dominguez-Vazquez, G.; Erlandson, J. M.; Firestone, R. B.; French, T. A.; Howard, G.; Israde-Alcántara, I.; Johnson, J. R.; Kimbel, D.; Kinzie, Ch. R.; Kurbatov, A.; Kletetschka, Günther; LeCompte, M. A.; Mahaney, W. C.; Mellot, A. L.; Mitra, S.; Maiorana-Boutilier, A.; Moore, Ch. R.; Napier, W. M.; Parlier, J.; Tankersley, K. B.; Thomas, B. C.; Wittke, J. H.; West, A.; Kennett, J. P.

2018-01-01

Roč. 126, č. 2 (2018), s. 185-205 ISSN 0022-1376 Institutional support: RVO:67985831 Keywords : biomass burning * climate feedback * climate variation * ice core * lacustrine deposit * marine sediment * paleoclimate * quantitative analysis * terrestrial deposit * winter * Younger Dryas Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 1.952, year: 2016

Chronological evidence fails to support claim of an isochronous widespread layer of cosmic impact indicators dated to 12,800 years ago

Science.gov (United States)

Meltzer, David J.; Holliday, Vance T.; Cannon, Michael D.; Miller, D. Shane

2014-05-01

According to the Younger Dryas Impact Hypothesis (YDIH), ∼12,800 calendar years before present, North America experienced an extraterrestrial impact that triggered the Younger Dryas and devastated human populations and biotic communities on this continent and elsewhere. This supposed event is reportedly marked by multiple impact indicators, but critics have challenged this evidence, and considerable controversy now surrounds the YDIH. Proponents of the YDIH state that a key test of the hypothesis is whether those indicators are isochronous and securely dated to the Younger Dryas onset. They are not. We have examined the age basis of the supposed Younger Dryas boundary layer at the 29 sites and regions in North and South America, Europe, and the Middle East in which proponents report its occurrence. Several of the sites lack any age control, others have radiometric ages that are chronologically irrelevant, nearly a dozen have ages inferred by statistically and chronologically flawed age-depth interpolations, and in several the ages directly on the supposed impact layer are older or younger than ∼12,800 calendar years ago. Only 3 of the 29 sites fall within the temporal window of the YD onset as defined by YDIH proponents. The YDIH fails the critical chronological test of an isochronous event at the YD onset, which, coupled with the many published concerns about the extraterrestrial origin of the purported impact markers, renders the YDIH unsupported. There is no reason or compelling evidence to accept the claim that a cosmic impact occurred ∼12,800 y ago and caused the Younger Dryas.

A Younger Dryas re-advance of local glaciers in north Greenland

Science.gov (United States)

Larsen, Nicolaj K.; Funder, Svend; Linge, Henriette; Möller, Per; Schomacker, Anders; Fabel, Derek; Xu, Sheng; Kjær, Kurt H.

2016-09-01

The Younger Dryas (YD) is a well-constrained cold event from 12,900 to 11,700 years ago but it remains unclear how the cooling and subsequent abrupt warming recorded in ice cores was translated into ice margin fluctuations in Greenland. Here we present 10Be surface exposure ages from three moraines in front of local glaciers on a 50 km stretch along the north coast of Greenland, facing the Arctic Ocean. Ten ages range from 11.6 ± 0.5 to 27.2 ± 0.9 ka with a mean age of 12.5 ± 0.7 ka after exclusion of two outliers. We consider this to be a minimum age for the abandonment of the moraines. The ages of the moraines are furthermore constrained using Optically Stimulated Luminescence (OSL) dating of epishelf sediments, which were deposited prior to the ice advance that formed the moraines, yielding a maximum age of 12.4 ± 0.6 ka, and bracketing the formation and subsequent abandonment of the moraines to within the interval 11.8-13.0 ka ago. This is the first time a synchronous YD glacier advance and subsequent retreat has been recorded for several independent glaciers in Greenland. In most other areas, there is no evidence for re-advance and glaciers were retreating during YD. We explain the different behaviour of the glaciers in northernmost Greenland as a function of their remoteness from the Atlantic Meridional Overturning Circulation (AMOC), which in other areas has been held responsible for modifying the YD drop in temperatures.

Hydrological and vegetational response to the Younger Dryas climatic oscillations: a high resolution case study from Quoyloo Meadow, Orkney, Scotland

Science.gov (United States)

Maas, David; Abrook, Ashley; Timms, Rhys; Matthews, Ian; Palmer, Adrian; Milner, Alice; Candy, Ian; Sachse, Dirk

2016-04-01

The Younger Dryas (Loch Lomond) Stadial is a well defined period of cold climate that in North West Europe punctuated the climatic amelioration during the Last Glacial - Interglacial Transition (LGIT ca. 16-8 ka). A palaeolake record from Quoyloo Meadow, Orkney Islands (N59.067, E-3.309) has been analysed for pollen and stable isotopes on biomarker lipids. n-Alkanes from terrestrial and aquatic sources are present throughout the core. The average chain length (ACL) is relatively low during the interstadial (~28.0) and shows a distinct increase during the Younger Dryas (to 29.0 +), attributed to an increase in grasses and drought resistant shrubs (e.g. Artemisia, Castañeda et al., 2009, Bunting, 1994). At the beginning of the Holocene, the ACL rapidly drops to 28.3 and from thereon gently increases again to ~29.0. There is a continued odd-over-even n-alkane predominance, although even n-alkanes are present in greater quantities in the interstadial, indicating an increasing terrestrial contribution in the Holocene. Ongoing deuterium isotope measurements of the n-alkanes will give independent evidence for palaeohydrological changes and can be compared to the other proxy evidence within the same core. Using a combination of nC29 and nC23 (terrestrial and aquatic end-members, respectively), a change in relative humidity (rH) can be qualified. This is based on the idea that terrestrial vegetation is affected by evapotranspiration processes, whereas aquatic vegetation is not (Rach et al., 2014). This data is supported by a high resolution palynological study; the contiguously sampled record demonstrates ecosystem/environmental responses to millennial-scale climatic change and allows for the possible detection of vegetation shifts at the sub-millennial scale. Vegetation aside, the pollen data can further aid in the interpretation of the recorded n-alkanes and isotopic analyses. This data is placed within a chronological framework derived from a high resolution crypto- and

Evidences of melting of terrestrial sediments and paleoenvironment changes during the Younger Dryas in tectonic lacustrine basins of Transmexican Volcanic Belt, Mexico.

Science.gov (United States)

Israde-Alcantara, I.

2017-12-01

It is well known in the sedimentary record of several parts of the world that during the Younger Dryas interval (YD) ocurred an abrupt environmental change between 12,900 and 11,700 cal yr BP (10,900 to 10,000 14C BP). In the lacustrine basins this changes are often preserved and in some Mexican lakes this is a distinctive stratigraphic marker for the YD. We analized the proxies of this event in cores of two lakes (Chapala, Cuitzeo) and three trenches of ex-lakes (Acambay,Texcoco and El Cedral). Deposits consist of fine detrital material with often Pleistocene fossil vertebrate assemblages. At the Chapala, Cuitzeo, Acambay, and Tocuila lacustrine environments are found in association with a distinctive dark organic layer showing sharp changes in the diatom, pollen, mineralogical and geochemical record. Includes also microscopic magnetic, Fe-rich spherules, silica melted droplets with aerodynamic shapes (tektites), followed by large amounts of charcoal, and sometimes nanodiamonds (Cuitzeo), that were deposited at the onset of the YD or in the limit Pleistocene-Holocene. These unusual materials are buried more than 2.50 meters and were not observed above or below the Younger Dryas sediments at these sites. The geochemistry of the microspherules indicates that they are not volcanic, anthropogenic or authigenic origin. A very distinctive feature is the shape of the spherules, ovoid, polygonal, filigreed or dendritic indicating melting and quenching infering that are product of an impact event. Their morphologies includes hollow shells caused by de-gassing of elements at very high temperatures causing a flattened side with a "skirt" structure by a high-velocity collision.Our results are consistent with the Firestone hypothesis.

Younger-Dryas cooling and sea-ice feedbacks were prominent features of the Pleistocene-Holocene transition in Arctic Alaska

Science.gov (United States)

Gaglioti, Benjamin V.; Mann, Daniel H.; Wooller, Matthew J.; Jones, Benjamin M.; Wiles, Gregory C.; Groves, Pamela; Kunz, Michael L.; Baughman, Carson A.; Reanier, Richard E.

2017-08-01

Declining sea-ice extent is currently amplifying climate warming in the Arctic. Instrumental records at high latitudes are too short-term to provide sufficient historical context for these trends, so paleoclimate archives are needed to better understand the functioning of the sea ice-albedo feedback. Here we use the oxygen isotope values of wood cellulose in living and sub-fossil willow shrubs (δ18Owc) (Salix spp.) that have been radiocarbon-dated (14C) to produce a multi-millennial record of climatic change on Alaska's North Slope during the Pleistocene-Holocene transition (13,500-7500 calibrated 14C years before present; 13.5-7.5 ka). We first analyzed the spatial and temporal patterns of δ18Owc in living willows growing at upland sites and found that over the last 30 years δ18Owc values in individual growth rings correlate with local summer temperature and inter-annual variations in summer sea-ice extent. Deglacial δ18Owc values from 145 samples of subfossil willows clearly record the Allerød warm period (∼13.2 ka), the Younger Dryas cold period (12.9-11.7 ka), and the Holocene Thermal Maximum (11.7-9.0 ka). The magnitudes of isotopic changes over these rapid climate oscillations were ∼4.5‰, which is about 60% of the differences in δ18Owc between those willows growing during the last glacial period and today. Modeling of isotope-precipitation relationships based on Rayleigh distillation processes suggests that during the Younger Dryas these large shifts in δ18Owc values were caused by interactions between local temperature and changes in evaporative moisture sources, the latter controlled by sea ice extent in the Arctic Ocean and Bering Sea. Based on these results and on the effects that sea-ice have on climate today, we infer that ocean-derived feedbacks amplified temperature changes and enhanced precipitation in coastal regions of Arctic Alaska during warm times in the past. Today, isotope values in willows on the North Slope of Alaska are similar

Younger-Dryas cooling and sea-ice feedbacks were prominent features of the Pleistocene-Holocene transition in Arctic Alaska

Science.gov (United States)

Gaglioti, Benjamin V.; Mann, Daniel H.; Wooller, Matthew J.; Jones, Benjamin M.; Wiles, Gregory C.; Groves, Pamela; Kunz, Michael L.; Baughman, Carson; Reanier, Richard E.

2017-01-01

Declining sea-ice extent is currently amplifying climate warming in the Arctic. Instrumental records at high latitudes are too short-term to provide sufficient historical context for these trends, so paleoclimate archives are needed to better understand the functioning of the sea ice-albedo feedback. Here we use the oxygen isotope values of wood cellulose in living and sub-fossil willow shrubs (δ18Owc) (Salix spp.) that have been radiocarbon-dated (14C) to produce a multi-millennial record of climatic change on Alaska's North Slope during the Pleistocene-Holocene transition (13,500–7500 calibrated 14C years before present; 13.5–7.5 ka). We first analyzed the spatial and temporal patterns of δ18Owc in living willows growing at upland sites and found that over the last 30 years δ18Owc values in individual growth rings correlate with local summer temperature and inter-annual variations in summer sea-ice extent. Deglacial δ18Owcvalues from 145 samples of subfossil willows clearly record the Allerød warm period (∼13.2 ka), the Younger Dryas cold period (12.9–11.7 ka), and the Holocene Thermal Maximum (11.7–9.0 ka). The magnitudes of isotopic changes over these rapid climate oscillations were ∼4.5‰, which is about 60% of the differences in δ18Owc between those willows growing during the last glacial period and today. Modeling of isotope-precipitation relationships based on Rayleigh distillation processes suggests that during the Younger Dryas these large shifts in δ18Owc values were caused by interactions between local temperature and changes in evaporative moisture sources, the latter controlled by seaice extent in the Arctic Ocean and Bering Sea. Based on these results and on the effects that sea-ice have on climate today, we infer that ocean-derived feedbacks amplified temperature changes and enhanced precipitation in coastal regions of Arctic Alaska during warm times in the past. Today, isotope values in willows on the North Slope of Alaska are

Hunted gazelles evidence cooling, but not drying, during the Younger Dryas in the southern Levant

Science.gov (United States)

Hartman, Gideon; Bar-Yosef, Ofer; Brittingham, Alex; Grosman, Leore; Munro, Natalie D.

2016-04-01

The climatic downturn known globally as the Younger Dryas (YD; ∼12,900-11,500 BP) has frequently been cited as a prime mover of agricultural origins and has thus inspired enthusiastic debate over its local impact. This study presents seasonal climatic data from the southern Levant obtained from the sequential sampling of gazelle tooth carbonates from the Early and Late Natufian archaeological sites of Hayonim and Hilazon Tachtit Caves (western Galilee, Israel). Our results challenge the entrenched model that assumes that warm temperatures and high precipitation are synonymous with climatic amelioration and cold and wet conditions are combined in climatic downturns. Enamel carbon isotope values from teeth of human-hunted gazelle dating before and during the YD provide a proxy measure for water availability during plant growth. They reveal that although the YD was cooler, it was not drier than the preceding Bølling-Allerød. In addition, the magnitude of the seasonal curve constructed from oxygen isotopes is significantly dampened during the YD, indicating that cooling was most pronounced in the growing season. Cool temperatures likely affected the productivity of staple wild cereal resources. We hypothesize that human groups responded by shifting settlement strategies-increasing population mobility and perhaps moving to the warmer Jordan Valley where wild cereals were more productive and stable.

Behaviour of the lake district ice lobe of the Scandinavian ice sheet during the younger dryas chronozone (ca. 12 800 - 11 500 years ago)

Energy Technology Data Exchange (ETDEWEB)

Lunkka, J.P.; Erikkilae, A. [Oulu Univ. (Finland)

2012-04-15

It is highly relevant to picture the conditions that prevailed under and in front of the ice sheets as they were stationary or in equilibrium for many hundreds of years. This knowledge is particularly relevant when planning to dispose of spent nuclear fuel in a repository underground. For estimating what kind of conditions might exist at the ice margin basic knowledge is needed from the palaeoice sheets that remained stationary for long periods of time. During Younder Dryas Stadial (c. 12 800 - 11 500 years ago) glaciers remained stationary or advanced worldwide as a result of climate cooling. The major end moraine complexes that run around Fennoscandia, Russian Karelia and the Kola Peninsula were deposited at that time and mark the former Younger Dryas ice margin. It this work the palaeoenvironments have been reconstructed in order to reveal the conditions that existed for more than 1000 years in the area where the former Lake District Ice Lobe of the Scandinavian Ice Sheet was in the Salpausselkae zone in southern Finland. Work was carried out using GIS-based reconstruction tools, sedimentological and geophysical (ground penetrating radar) methods. In addition, a detailed palaeoenvironmental reconstruction was produced for the Kylaeniemi area which forms a part of the Salpausselkae II end moraine. The GIS-based reconstructions clearly indicate that the ice grounding line of the Lake District Ice Lobe was standing in shallow water depth in the Baltic Ice Lake. The water depth in front of Salpausselkae I, which marks the ice margin at c. 12 500 years ago was mainly between 20-40 metres. When the ice margin was in Salpausselkae II at around 11 700 years ago the water depth in front of the ice margin was on average less than 20 metres. Although the surface profile of ice was not possible to calculate subgalcial and ice frontal landforms indicate that subgalcial tunnel systems were responsible for releasing melt water and sediment to the ice margin throughout the

Behaviour of the lake district ice lobe of the Scandinavian ice sheet during the younger dryas chronozone (ca. 12 800 - 11 500 years ago)

International Nuclear Information System (INIS)

Lunkka, J.P.; Erikkilae, A.

2012-04-01

It is highly relevant to picture the conditions that prevailed under and in front of the ice sheets as they were stationary or in equilibrium for many hundreds of years. This knowledge is particularly relevant when planning to dispose of spent nuclear fuel in a repository underground. For estimating what kind of conditions might exist at the ice margin basic knowledge is needed from the palaeoice sheets that remained stationary for long periods of time. During Younder Dryas Stadial (c. 12 800 - 11 500 years ago) glaciers remained stationary or advanced worldwide as a result of climate cooling. The major end moraine complexes that run around Fennoscandia, Russian Karelia and the Kola Peninsula were deposited at that time and mark the former Younger Dryas ice margin. It this work the palaeoenvironments have been reconstructed in order to reveal the conditions that existed for more than 1000 years in the area where the former Lake District Ice Lobe of the Scandinavian Ice Sheet was in the Salpausselkae zone in southern Finland. Work was carried out using GIS-based reconstruction tools, sedimentological and geophysical (ground penetrating radar) methods. In addition, a detailed palaeoenvironmental reconstruction was produced for the Kylaeniemi area which forms a part of the Salpausselkae II end moraine. The GIS-based reconstructions clearly indicate that the ice grounding line of the Lake District Ice Lobe was standing in shallow water depth in the Baltic Ice Lake. The water depth in front of Salpausselkae I, which marks the ice margin at c. 12 500 years ago was mainly between 20-40 metres. When the ice margin was in Salpausselkae II at around 11 700 years ago the water depth in front of the ice margin was on average less than 20 metres. Although the surface profile of ice was not possible to calculate subgalcial and ice frontal landforms indicate that subgalcial tunnel systems were responsible for releasing melt water and sediment to the ice margin throughout the

Evidence from Central Mexico Supporting the Younger Dryas Extraterrestrial Impact Hypothesis

Science.gov (United States)

2012-03-05

numerous sites across North America, Greenland, and Western Europe. We have examined multiple hy- potheses to account for these observations and find...ka, a difference of approximately 20 kyr. Accounting for this shift requires major contamination of the TOC by radiocarbon- dead or very old carbon...before present; char, charcoal. §Van Hoesel A, Hoek W, Braadbaart F, van der Plicht H, Drury MR, Nanodiamonds and the Usselo layer, INQUA XVIII, July 21

Abrupt sea surface pH change at the end of the Younger Dryas in the central sub-equatorial Pacific inferred from boron isotope abundance in corals (Porites

Directory of Open Access Journals (Sweden)

A. Juillet-Leclerc

2010-08-01

Full Text Available The "δ11B-pH" technique was applied to modern and ancient corals Porites from the sub-equatorial Pacific areas (Tahiti and Marquesas spanning a time interval from 0 to 20.720 calendar years to determine the amplitude of pH changes between the Last Glacial Period and the Holocene. Boron isotopes were measured by Multi-Collector – Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS with an external reproducibility of 0.25‰, allowing a precision of about ±0.03 pH-units for pH values between 8 and 8.3. The boron concentration [B] and isotopic composition of modern samples indicate that the temperature strongly controls the partition coefficient KD for different aragonite species. Modern coral δ11B values and the reconstructed sea surface pH values for different Pacific areas match the measured pH expressed on the seawater scale and confirm the calculation parameters that were previously determined by laboratory calibration exercises. Most ancient sea surface pH reconstructions near Marquesas are higher than modern values. These values range between 8.19 and 8.27 for the Holocene and reached 8.30 at the end of the last glacial period (20.7 kyr BP. At the end of the Younger Dryas (11.50±0.1 kyr BP, the central sub-equatorial Pacific experienced a dramatic drop of up to 0.2 pH-units from the average pH of 8.2 before and after this short event. Using the marine carbonate algorithms, we recalculated the aqueous pCO2 to be 440±25 ppmV at around 11.5 kyr BP for corals at Marquesas and ~500 ppmV near Tahiti where it was assumed that pCO2 in the atmosphere was 250 ppmV. Throughout the Holocene, the difference in pCO2 between the ocean and the atmosphere at Marquesas (ΔpCO2 indicates that the surface waters behave as a moderate CO2 sink or source (−53 to 20 ppmV during El Niño-like conditions. By contrast, during the last glacial/interglacial transition, this area was a marked source of CO2 (21 to 92 ppmV for the atmosphere, highlighting

Human Population Decline in North America during the Younger Dryas

Science.gov (United States)

Anderson, D. G.; Goodyear, A. C.; Stafford, T. W., Jr.; Kennett, J.; West, A.

2009-12-01

There is ongoing debate about a possible human population decline or contraction at the onset of the Younger Dryas (YD) at 12.9 ka. We used two methods to test whether the YD affected human population levels: (1) frequency analyses of Paleoindian projectile points, and (2) summed probability analyses of radiocarbon (14C) dates. The results suggest that a significant decline or reorganization of human populations occurred at 12.9 ka, continued through the initial centuries of the YD chronozone, then rebounded by the end of the YD. FREQUENCY ANALYSES: This method employed projectile point data from the Paleoindian Database of the Americas (PIDBA, http://pidba.utk.edu). We tallied diagnostic projectile points and obtained larger totals for Clovis points than for immediately post-Clovis points, which share an instrument-assisted fluting technique, typically using pressure or indirect percussion. Gainey, Vail, Debert, Redstone, and Cumberland point-styles utilized this method and are comparable to the Folsom style. For the SE U.S., the ratio of Clovis points (n=1993) to post-Clovis points (n=947) reveals a point decline of 52%. For the Great Plains, a comparison of Clovis and fluted points (n=4020) to Folsom points (n=2527) shows a point decline of 37%, which may translate into a population contraction of similar magnitude. In addition, eight major Clovis lithic quarry sites in the SE U.S. exhibit little to no evidence for immediate post-Clovis occupations, implying a major population decline. SUMMED PROBABILITIES: This method involved calibrating relevant 14C dates and combining the probabilities, after which major peaks and troughs in the trends are assumed to reflect changes in human demographics. Using 14C dates from Buchanan et al. (2008), we analyzed multiple regions, including the Southeast and Great Plains. Contrary to Buchanan et al., we found an abrupt, statistically significant decline at 12.9 ka, followed 200 to 900 years later by a rebound in the number of

Climate Reconstructions of the Younger Dryas: An ELA Model Investigating Variability in ELA Depressions, Temperature, and Precipitation Changes for the Graubϋnden Alps

Science.gov (United States)

Keeler, D. G.; Rupper, S.; Schaefer, J. M.; Finkel, R. C.

2015-12-01

The high sensitivity of mountain glaciers to even small perturbations in climate, combined with a near global distribution, make alpine glaciers an important target for terrestrial paleoclimate reconstructions. The geomorphic remnant of past glaciers can yield important insights into past climate, particularly in regions where other methods of reconstruction are not possible. The quantitative conversion of these changes in geomorphology to a climate signal, however, presents a significant challenge. A particular need exists for a versatile climate reconstruction method applicable to diverse glacierized regions around the globe. Because the glacier equilibrium line altitude (ELA) provides a more explicit comparison of climate than properties such as glacier length or area, ELA methods lend themselves well to such a need, and allow for a more direct investigation of the primary drivers of mountain glaciations during specific events. Here, we present an ELA model for quantifying changes in climate based on changes in glacier extent, while accounting for differences in glacier width, glacier shape, bed topography, ice thickness, and glacier length. The model furthermore provides bounds on the ΔELA using Monte Carlo simulations. These methods are validated using published mass balances and ELA measurements from 4 modern glaciers in the European Alps. We then use this ELA model, combined with a surface mass and energy balance model, to estimate the changes in temperature/precipitation between the Younger Dryas (constrained by 10Be surface exposure ages) and the present day for three glacier systems in the Graubϋnden Alps. Our results indicate an ELA depression in this area of 257 m ±45 m during the Younger Dryas (YD) relative to today. This corresponds to a 1.3 °C ±0.36 °C decrease in temperature or a 156% ±30% increase in precipitation relative to today. These results indicate the likelihood of a predominantly temperature-driven change rather than a strong

Regional scale climatic trends derived from Younger Dryas glaciers in the U.K.

Science.gov (United States)

Pearce, D.; Rea, B. R.; Barr, I.; Small, D.; McDougall, D.

2014-12-01

In the U.K., the glacial geomorphological record has been utilised to infer paleo-glacier geometries and ice dynamics, with much of this work focussing on the Scottish Highlands during the Younger Dryas (YD; c. 12.9 - 11.7 ka BP). During the YD the West Highlands Ice-cap covered the majority of the Scottish Highlands (c. 13,000 sq mi), which is thought to have affected accumulation rates beyond the ice-cap margins, resulting in a steep (c. 80%) easterly decline in precipitation and smaller ice-masses. We present multi-proxy data investigating YD glaciation in the Tweedsmuir Hills, Southern Uplands, Scotland (55°46' N, 03°34' W), suggesting conditions were less arid. The area forms the most easterly upland region in the Southern Uplands and south of the West Highlands Ice-cap, reaching an altitude of 840 m and covering c. 200 sq mi. Results of air-photo interpretation and field mapping, which utilised a morphostratigraphic approach, have demonstrated a more extensive glaciation than previously mapped. The reconstruction consists of two separate icefields covering an area c. 40 sq mi. and new 14C dates of basal contact organics place the ice-mass within the context of the YD but new Cosmogenic Nuclide Analysis (CNA) of bedrock and in situ boulders are inconclusive, implying limited erosion and limited resetting during the YD. Equilibrium Line Altitudes are calculated to have ranged from c. 419 - 634 m. Paleo-precipitation values were derived using two precipitation-temperature relationships and suggest slightly lower totals than YD ice-masses located on the west coast of the U.K. but do not support a significant easterly reduction in precipitation. Analysis of present-day (c. 30 year) meteorological data across the U.K. demonstrates a pronounced reduction in precipitation of c. 50% on the east coast. This disparity between present-day and glacier-based YD precipitation patterns is partly attributable to the methodology employed in glacier reconstruction and

Reply to comment by E. Bard et al. on "Younger Dryas sea level and meltwater pulse 1B recorded in Barbados reef crest coral Acropora palmata" by N. A. Abdul et al.

Science.gov (United States)

Mortlock, Richard A.; Abdul, Nicole A.; Wright, James D.; Fairbanks, Richard G.

2016-12-01

Abdul et al. (2016) presented a detailed record of sea level at Barbados (13.9-9 kyr B.P.) tightly constraining the timing and amplitude during the Younger Dryas and Meltwater Pulse 1B (MWP-1B) based on U-Th dated reef crest coral species Acropora palmata. The Younger Dryas slow stand and the large (14 m) rapid sea level jump are not resolved in the Tahiti record. Tahiti sea level estimates are remarkably close to the Barbados sea level curve between 13.9 and 11.6 kyr but fall below the Barbados sea level curve for a few thousand years following MWP-1B. By 9 kyr the Tahiti sea level estimates again converge with the Barbados sea level curve. Abdul et al. (2016) concluded that Tahiti reefs at the core sites did not keep up with intervals of rapidly rising sea level during MWP-1B. We counter Bard et al. (2016) by showing (1) that there is no evidence for a hypothetical fault in Oistins Bay affecting one of the Barbados coring locations, (2) that the authors confuse the rare occurrences of A. palmata at depths >5 m with the "thickets" of A. palmata fronds representing the reef-crest facies, and (3) that uncertainties in depth habitat proxies largely account for differences in Barbados and Tahiti sea level differences curves with A. palmata providing the most faithful proxy. Given the range in Tahiti paleodepth uncertainties at the cored sites, the most parsimonious explanation remains that Tahiti coralgal ridges did not keep up with the sea level rise of MWP-1B.

Glaciation style and the geomorphological record: evidence for Younger Dryas glaciers in the eastern Lake District, northwest England

Science.gov (United States)

McDougall, Derek

2013-08-01

The Younger Dryas (c. 12,900-11,700 years ago) in Britain witnessed renewed glaciation, with the readvance of ice masses that had survived the preceding Lateglacial Interstadial as well as the formation of new glaciers. The extents of these former glaciers have been mapped by many workers over the past fifty years, usually as a basis for palaeoclimatic investigations. It has frequently been asserted that the landform record is sufficiently clear to allow accurate ice mass reconstructions at or near maximum extents. Detailed geomorphological mapping in the eastern Lake District in NW England, however, demonstrates that this confidence may not always be warranted. Whereas previous workers have interpreted the well-developed moraines that exist in some locations as evidence for an alpine-style of glaciation, with ice restricted to a small number of valleys, this study shows that the most recent glaciation to affect the area was characterised by: (i) extensive summit icefields, which supplied ice to the surrounding valleys; and (ii) a much greater volume of ice in the valleys than previously thought. The discovery that summit icefields were relatively common at this time is consistent with recent studies elsewhere in the Lake District and beyond. More significant, however, is the recognition that changing glacier-topographic interactions over both space and time appears to have had a profound impact on valley-floor glacial landform development, with the absence of clear moraines not necessarily indicating ice-free conditions at this time. This complicates glacier reconstructions based solely on the geomorphological record. Similar geomorphological complexity may be present in other areas that previously supported summit icefields, and this needs to be taken into account in glacier reconstructions.

Proliferation and demise of deep-sea corals in the Mediterranean during the Younger Dryas

International Nuclear Information System (INIS)

McCulloch, Malcolm; Taviani, Marco; Lopez Correa, Matthias; Remia, Alessandro; Montagna, Paolo; Mortimer, Graham

2010-01-01

Uranium-series and radiocarbon ages are reported for deep-sea corals Madrepora oculata, Desmophyllum dianthus, Lophelia pertusa and Caryophyllia smithii from the Mediterranean Sea. U-series dating indicates that deep-sea corals have persisted in the Mediterranean for over 480, 000 years, especially during cool inter-stadial periods. The most prolific period of growth however appears to have occurred within the Younger Dryas (YD) period from 12, 900 to 11, 700 years BP followed by a short (∼ 330 years) phase of post-YD coral growth from 11, 230 to 10, 900 years BP. This indicates that deep-sea corals were prolific in the Mediterranean not only during the return to the more glacial-like conditions of the YD, but also following the rapid deglaciation and transition to warmer conditions that followed the end of the YD. Surprisingly, there is a paucity Last Glacial Maximum (LGM) coral ages, implying they were largely absent during this period when cold-water conditions were more prevalent. Radiocarbon ages show that the intermediate depth waters of the Mediterranean generally had Δ 14 C compositions similar to surface waters, indicating that these waters were extremely well ventilated. The only exception is a narrow period in the YD (12, 500 ± 100 years BP) when several samples of Lophelia pertusa from the Ionian Sea had Δ 14 C values falling significantly below the marine curve. Using a refined approach, isolation ages (T isol ) of 300 years to 500 years are estimated for these intermediate (800-1000 m) depth waters relative to surface marine waters, indicating a reduction or absence of deep-water formation in the Ionian and adjacent Adriatic Seas during the YD. Contrary to previous findings, we find no evidence for widespread intrusion of low Δ 14 C Atlantic waters into the Mediterranean. Prolific growth of deep-sea corals in the Mediterranean ended abruptly at ∼ 10, 900 years BP, with many of the coral-bearing mounds on the continental slopes being draped in

Proliferation and demise of deep-sea corals in the Mediterranean during the Younger Dryas

Energy Technology Data Exchange (ETDEWEB)

McCulloch, Malcolm [ARC Centre of Excellence for Coral Reef Studies, School of Earth and Environment, The University of Western Australian, Crawley, 6009, Western Australia (Australia); Research School of Earth Sciences, Australian National University, Canberra, 0200 (Australia); Taviani, Marco; Lopez Correa, Matthias; Remia, Alessandro [ISMAR-CNR, via Gobetti 101, I-40129 Bologna (Italy); Montagna, Paolo [LSCE, Av. de la Terrasse, 91198 Gif-sur-Yvette, France, ISMAR-CNR, via Gobetti 101, I-40129 Bologna (Italy); Mortimer, Graham [Research School of Earth Sciences, Australian National University, Canberra, 0200 (Australia)

2010-07-01

Uranium-series and radiocarbon ages are reported for deep-sea corals Madrepora oculata, Desmophyllum dianthus, Lophelia pertusa and Caryophyllia smithii from the Mediterranean Sea. U-series dating indicates that deep-sea corals have persisted in the Mediterranean for over 480, 000 years, especially during cool inter-stadial periods. The most prolific period of growth however appears to have occurred within the Younger Dryas (YD) period from 12, 900 to 11, 700 years BP followed by a short ({approx} 330 years) phase of post-YD coral growth from 11, 230 to 10, 900 years BP. This indicates that deep-sea corals were prolific in the Mediterranean not only during the return to the more glacial-like conditions of the YD, but also following the rapid deglaciation and transition to warmer conditions that followed the end of the YD. Surprisingly, there is a paucity Last Glacial Maximum (LGM) coral ages, implying they were largely absent during this period when cold-water conditions were more prevalent. Radiocarbon ages show that the intermediate depth waters of the Mediterranean generally had {Delta}{sup 14}C compositions similar to surface waters, indicating that these waters were extremely well ventilated. The only exception is a narrow period in the YD (12, 500 {+-} 100 years BP) when several samples of Lophelia pertusa from the Ionian Sea had {Delta}{sup 14}C values falling significantly below the marine curve. Using a refined approach, isolation ages (T{sub isol}) of 300 years to 500 years are estimated for these intermediate (800-1000 m) depth waters relative to surface marine waters, indicating a reduction or absence of deep-water formation in the Ionian and adjacent Adriatic Seas during the YD. Contrary to previous findings, we find no evidence for widespread intrusion of low {Delta}{sup 14}C Atlantic waters into the Mediterranean. Prolific growth of deep-sea corals in the Mediterranean ended abruptly at {approx} 10, 900 years BP, with many of the coral-bearing mounds

Extraterrestrial Life

Science.gov (United States)

Klein, M. J.

1993-01-01

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

Subglacial hydrology of the lake district ice lobe during the Younger Dryas (ca. 12 500 - 11 600 years ago) in the Kylaeniemi area, SE Finland

Energy Technology Data Exchange (ETDEWEB)

Lunkka, J. P.; Moisio, K.; Vainio, A. [Univ. of Oulu (Finland)

2013-07-15

It is essential to gain knowledge on the subglacial hydrological conditions at the glacier bed / bedrock interface when assessing how bedrock fracture zones affect subglacial melt water flow and in which subglacial zones pressurized and oxygen-rich melt water penetrates into the bedrock fracture systems. In the warm-based glacier zones, a part of subglacial melt water will penetrate deep into the fracture systems although the major part of melt water is drained to and beyond the ice margin via subglacial tunnel networks especially in the areas where ice is flowing on the crystalline bedrock. During the last deglaciation phase of the former Scandinavian Ice Sheet, glaciofluvial accumulations were deposited and these sediment accumulations are highly important when picturing the subglacial hydrology of different ice streams during deglaciation in the crystalline bedrock area. The aim of the present work was to map the bedrock fracture zones in the Kylaeniemi area and to shed light on the subglacial hydrology of the Scandinavian Ice Sheet's Lake District Ice Stream that occupied the Kylaeniemi area during the Younger Dryas between ca. 12 500 - 11 600 years ago. The special emphasis within this general aim was to study the relationship between bedrock fracture zones and the routes of subglacial drainage paths. The methods used to map and study bedrock fracture zones and subglacial drainage paths included remotes sensing methods, field observations, ground penetrating radar (GPR) investigations and GIS-based reconstructions. Conventional geological field methods aided by the GPR-method were also used to map bedrock exposures and their structures and to define the type of glaciofluvial sediments and glaciofluvial landform associations. Two main fracture zone sets occur in the study area. The most prominent bedrock fracture zone set trends NW-SE while the other, less prominent fracture zone set is aligned in NE-SW direction. The majority of the minor joint sets in

Subglacial hydrology of the lake district ice lobe during the Younger Dryas (ca. 12 500 - 11 600 years ago) in the Kylaeniemi area, SE Finland

International Nuclear Information System (INIS)

Lunkka, J. P.; Moisio, K.; Vainio, A.

2013-07-01

It is essential to gain knowledge on the subglacial hydrological conditions at the glacier bed / bedrock interface when assessing how bedrock fracture zones affect subglacial melt water flow and in which subglacial zones pressurized and oxygen-rich melt water penetrates into the bedrock fracture systems. In the warm-based glacier zones, a part of subglacial melt water will penetrate deep into the fracture systems although the major part of melt water is drained to and beyond the ice margin via subglacial tunnel networks especially in the areas where ice is flowing on the crystalline bedrock. During the last deglaciation phase of the former Scandinavian Ice Sheet, glaciofluvial accumulations were deposited and these sediment accumulations are highly important when picturing the subglacial hydrology of different ice streams during deglaciation in the crystalline bedrock area. The aim of the present work was to map the bedrock fracture zones in the Kylaeniemi area and to shed light on the subglacial hydrology of the Scandinavian Ice Sheet's Lake District Ice Stream that occupied the Kylaeniemi area during the Younger Dryas between ca. 12 500 - 11 600 years ago. The special emphasis within this general aim was to study the relationship between bedrock fracture zones and the routes of subglacial drainage paths. The methods used to map and study bedrock fracture zones and subglacial drainage paths included remotes sensing methods, field observations, ground penetrating radar (GPR) investigations and GIS-based reconstructions. Conventional geological field methods aided by the GPR-method were also used to map bedrock exposures and their structures and to define the type of glaciofluvial sediments and glaciofluvial landform associations. Two main fracture zone sets occur in the study area. The most prominent bedrock fracture zone set trends NW-SE while the other, less prominent fracture zone set is aligned in NE-SW direction. The majority of the minor joint sets in

Search for extraterrestrial intelligence (SETI)

International Nuclear Information System (INIS)

Morrison, P.; Billingham, J.; Wolfe, J.

1977-01-01

Findings are presented of a series of workshops on the existence of extraterrestrial intelligent life and ways in which extraterrestrial intelligence might be detected. The coverage includes the cosmic and cultural evolutions, search strategies, detection of other planetary systems, alternate methods of communication, and radio frequency interference. 17 references

Extraterrestrial altruism evolution and ethics in the cosmos

CERN Document Server

2014-01-01

Extraterrestrial Altruism examines a basic assumption of the Search for Extraterrestrial Intelligence (SETI): that extraterrestrials will be transmitting messages to us for our benefit. This question of whether extraterrestrials will be altruistic has become increasingly important in recent years as SETI scientists have begun contemplating transmissions from Earth to make contact. Should we expect altruism to evolve throughout the cosmos, or is this only wishful thinking? Would this make biological sense? Is it dangerous to send messages to other worlds, as Stephen Hawking has suggested? Would extraterrestrial societies be based on different ethical principles? Extraterrestrial Altruism explores these and related questions about the motivations of civilizations beyond Earth, providing new insights that are critical for SETI. Chapters are authored by leading scholars from diverse disciplines—anthropology, astronomy, biology, chemistry, computer science, cosmology, engineering, history of science, law, philos...

Universalist ethics in extraterrestrial encounter

Science.gov (United States)

Baum, Seth D.

2010-02-01

If humanity encounters an extraterrestrial civilization, or if two extraterrestrial civilizations encounter each other, then the outcome may depend not only on the civilizations' relative strength to destroy each other but also on what ethics are held by one or both civilizations. This paper explores outcomes of encounter scenarios in which one or both civilizations hold a universalist ethical framework. Several outcomes are possible in such scenarios, ranging from one civilization destroying the other to both civilizations racing to be the first to commit suicide. Thus, attention to the ethics of both humanity and extraterrestrials is warranted in human planning for such an encounter. Additionally, the possibility of such an encounter raises profound questions for contemporary human ethics, even if such an encounter never occurs.

Duties to Extraterrestrial Microscopic Organisms

Science.gov (United States)

Cockell, C. S.

Formulating a normative axiology for the treatment of extraterrestrial microscopic organisms, should they ever be found, requires an extension of environmental ethics to beyond the Earth. Using an ethical framework for the treatment of terrestrial micro-organisms, this paper elaborates a similar ethic for the treatment of extraterrestrial microscopic organisms. An ethic of `teloempathy' allows for the moral considerability of any organism that has `interests', based on rudimentary qualities of conativism, and therefore allows for an identical treatment of all life, related or not related to life on Earth. Although, according to this ethic, individual extraterrestrial microscopic organisms have a good of their own and even `rights', at this level the ethic can only be theoretical, allowing for the inevitable destruction of many individual organisms during the course of human exploratory missions, similarly to the daily destruction of microbes by humans on Earth. A holistic teloempathy, an operative ethic, not only provides a framework for human exploration, but it also has important implications for planetary protection and proposals to implement planetary-scale atmospheric alterations on other bodies. Even prior to the discovery of extraterrestrial life, or the discovery of a complete absence of such life, this exercise yields important insights into the moral philosophy that guides our treatment of terrestrial micro-organisms.

The Extraterrestrial Life Debate from Antiquity to 1900

Science.gov (United States)

Crowe, Michael J.; Dowd, Matthew F.

This chapter provides an overview of the Western historical debate regarding extraterrestrial life from antiquity to the beginning of the twentieth century. Though schools of thought in antiquity differed on whether extraterrestrial life existed, by the Middle Ages, the Aristotelian worldview of a unified, finite cosmos without extraterrestrials was most influential, though there were such dissenters as Nicholas of Cusa. That would change as the Copernican revolution progressed. Scholars such as Bruno, Kepler, Galileo, and Descartes would argue for a Copernican system of a moving Earth. Cartesian and Newtonian physics would eventually lead to a view of the universe in which the Earth was one of many planets in one of many solar systems extended in space. As this cosmological model was developing, so too were notions of extraterrestrial life. Popular and scientific writings, such as those by Fontenelle and Huygens, led to a reversal of fortunes for extraterrestrials, who by the end of the century were gaining recognition. From 1700 to 1800, many leading thinkers discussed extraterrestrial intelligent beings. In doing so, they relied heavily on arguments from analogy and such broad principles and ideas as the Copernican Principle, the Principle of Plenitude, and the Great Chain of Being. Physical evidence for the existence of extraterrestrials was minimal, and was always indirect, such as the sighting of polar caps on Mars, suggesting similarities between Earth and other places in the universe. Nonetheless, the eighteenth century saw writers from a wide variety of genres—science, philosophy, theology, literature—speculate widely on extraterrestrials. In the latter half of the century, increasing research in stellar astronomy would be carried out, heavily overlapping with an interest in extraterrestrial life. By the end of the eighteenth century, belief in intelligent beings on solar system planets was nearly universal and certainly more common than it would be by

How likely is extraterrestrial life?

CERN Document Server

Halley, J Woods

2012-01-01

What does existing scientific knowledge about physics, chemistry, meteorology and biology tell us about the likelihood of extraterrestrial life and civilizations? And what does the fact that there is currently no credible scientific evidence for the existence of extraterrestrial biospheres or civilizations teach  us? This book reviews the various scientific issues that arise in considering the question of how common extraterrestrial life is likely to be in our galaxy and whether humans are likely to detect it. The book stands out because of its very systematic organization and relatively unbiased treatment of the main open question. It covers all relevant aspects of many disciplines required to present the different   possible answers. It has and will provide undergraduates with a stimulating introduction to many of these fields at an early stage in their university careers, when they are still choosing a specialty. The difficulties and the range of possible answers to the title question are carefully addr...

Cosmogenic nuclide production within the atmosphere and long period comets

Science.gov (United States)

Overholt, Andrew C.

The Earth is constantly bombarded by cosmic rays. These high energy particles collide with target nuclei, producing a shower of secondary particles. These secondaries contribute significantly to the radiation background at sea level and in the atmosphere, as well as producing rare cosmogenic nuclides. This contribution is variable over long time scales as astrophysical events change the cosmic ray flux incident on the Earth. Our work re-examines a previously proposed climate effect of increased cosmic ray flux due to galactic location. Although our work does not support this effect, cosmic ray secondaries remain a threat to terrestrial biota. We calculate the cosmogenic neutron flux within the atmosphere as a function of primary spectrum. This work is pivotal in determining the radiation dose due to any arbitrary astrophysical event where the primary spectrum is known. Additionally, this work can be used to determine the cosmogenic nuclide production from such an event. These neutrons are the fundamental source of cosmogenic nuclides within our atmosphere and extraterrestrial matter. We explore the idea that excursions in 14C and 10Be abundances in the atmosphere may arise from direct deposition by long-period comet impacts, and those in 26Al from any bolide. We find that the amount of nuclide mass on large long-period comets entering the Earth's atmosphere may be sufficient for creating anomalies in the records of 14C and 10Be from past impacts. In particular, the estimated mass of the proposed Younger Dryas comet is consistent with its having deposited sufficient isotopes to account for recorded nuclide increases at that time. The 26Al/10Be ratio is much larger in extraterrestrial objects than in the atmosphere, and so, we note that measuring this ratio in ice cores is a suitable further test for the Younger Dryas impact hypothesis. This portion of our work may be used to find possible impact events in the geologic record as well as determination of a large

Radiocarbon dating and Dendrochronology for Statigraphic Units near Tebano, Senio Northern Apennines - Time frame of Climatic Fluctuation at the onset of the Younger Dryas

Science.gov (United States)

Eggenschwiler, Loren; Hajdas, Irka; Cherubini, Paolo; Picotti, Vincenzo; Saurer, Matthias

2017-04-01

The presence of Pinus [sylvestris] provides an insight into dramatic events due to climatic changes. Several major and minor climatic fluctuations have had a strong impact on terrestrial and marine environments since the last glacial period to present day (Ravazzi et al. 2006). This study aims to describe the response of a fluvial environment through the use of dendrochronology and stratigraphy. Here, we intend to get a better understanding of how these climatic fluctuations affect the behavior of the Senio River (Lotter et al. 1992). In Tebano, Italy, several Pinus sylvestris subfossil trunks were discovered during excavation for an irrigation pool. Subfossil samples were collected to analyze the climate during the Younger Dryas (11,000 years BP) in detail. Charcoal samples from the Bubano clay quarry extend our research to further to 35,500 cal. years BP. The combination of dendrochronology along with stratigraphy allowed us to examine the climate at a detailed local and apply it to a broader spectrum. Tree-ring measurements and cross dating provided a better understanding and verification of extreme events that occurred during the lifespans of the trees. The use of stable isotopes indicates the extreme conditions that occurred. Radiocarbon dating validates the age of the samples and what geological period they come from. Along with stratigraphy, we were able to compile depth data to create a sediment curve. Using various methods throughout this study, we discovered the climatic situation of Pinus 11,000 years BP and are able to compare them with samples from today. These present day samples mark two of the southernmost extents of the Pinus population. We were then able to comprehend the magnitude of sediment supply and precipitation. Through this collection of methods and data, we are able to understand the influence of climate change in the past and the potential changes of the future. REFERENCES Lotter, A. F.; Eicher, U.; Siegenthaler, U.; Birks, H. J. B

Climate bifurcation during the last deglaciation?

Directory of Open Access Journals (Sweden)

T. M. Lenton

2012-07-01

Full Text Available There were two abrupt warming events during the last deglaciation, at the start of the Bølling-Allerød and at the end of the Younger Dryas, but their underlying dynamics are unclear. Some abrupt climate changes may involve gradual forcing past a bifurcation point, in which a prevailing climate state loses its stability and the climate tips into an alternative state, providing an early warning signal in the form of slowing responses to perturbations, which may be accompanied by increasing variability. Alternatively, short-term stochastic variability in the climate system can trigger abrupt climate changes, without early warning. Previous work has found signals consistent with slowing down during the last deglaciation as a whole, and during the Younger Dryas, but with conflicting results in the run-up to the Bølling-Allerød. Based on this, we hypothesise that a bifurcation point was approached at the end of the Younger Dryas, in which the cold climate state, with weak Atlantic overturning circulation, lost its stability, and the climate tipped irreversibly into a warm interglacial state. To test the bifurcation hypothesis, we analysed two different climate proxies in three Greenland ice cores, from the Last Glacial Maximum to the end of the Younger Dryas. Prior to the Bølling warming, there was a robust increase in climate variability but no consistent slowing down signal, suggesting this abrupt change was probably triggered by a stochastic fluctuation. The transition to the warm Bølling-Allerød state was accompanied by a slowing down in climate dynamics and an increase in climate variability. We suggest that the Bølling warming excited an internal mode of variability in Atlantic meridional overturning circulation strength, causing multi-centennial climate fluctuations. However, the return to the Younger Dryas cold state increased climate stability. We find no consistent evidence for slowing down during the Younger Dryas, or in a longer

Extraterrestrial Metals Processing, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The Extraterrestrial Metals Processing (EMP) system produces ferrosilicon, silicon monoxide, a glassy mixed oxide slag, and smaller amounts of alkali earth...

Curating NASA's Past, Present, and Future Extraterrestrial Sample Collections

Science.gov (United States)

McCubbin, F. M.; Allton, J. H.; Evans, C. A.; Fries, M. D.; Nakamura-Messenger, K.; Righter, K.; Zeigler, R. A.; Zolensky, M.; Stansbery, E. K.

2016-01-01

The Astromaterials Acquisition and Curation Office (henceforth referred to herein as NASA Curation Office) at NASA Johnson Space Center (JSC) is responsible for curating all of NASA's extraterrestrial samples. Under the governing document, NASA Policy Directive (NPD) 7100.10E "Curation of Extraterrestrial Materials", JSC is charged with "...curation of all extra-terrestrial material under NASA control, including future NASA missions." The Directive goes on to define Curation as including "...documentation, preservation, preparation, and distribution of samples for research, education, and public outreach." Here we describe some of the past, present, and future activities of the NASA Curation Office.

Extraterrestrial Metals Processing, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The Extraterrestrial Metals Processing (EMP) system produces iron, silicon, and light metals from Mars, Moon, or asteroid resources in support of advanced human...

The Ethical Implications for Discovery of Extraterrestrial Life

Science.gov (United States)

Stuart, Jill

2012-05-01

Ethical frameworks seek to normatively structure our behaviour and preconstitute expectations with regards to moral activity towards each other as well as other creatures and even non-sentient objects such as the environment. This paper considers how ongoing ethical discussions relating to earth-based interactions can be used as analogies to inform nascent conversations about potential future encounters with extraterrestrial life—while also highlighting where these geocentric conversations may fail to capture the unique dynamics of potential extraterrestrial encounters. The paper specifically considers the spectrum of ethical frameworks currently used in earth-based interactions and how they might apply outside the geocentric referent; from ethics towards non- sentient life on earth such as plants and the environment; to ethics towards sentient but ‘unintelligent' life; to intelligent life nonetheless deemed less intelligent than humans. Next the paper considers interactions that we have yet to (knowingly) have encountered here on earth: the ethics of interactions with life more intelligent than ourselves; and finally the ethics of interaction with robotic ‘post-biological' forms, which some specialists in extraterrestrial communications have speculated will likely be the form of ‘creatures' to be encountered should contact with extraterrestrials ever be made. Finally the paper will address deeper philosophical-ethical questions about the significance of such an exercise in shifting ethical frameworks from an anthropocentric perspective.

Implications of extraterrestrial material on the origin of life

Science.gov (United States)

Pasek, Matthew A.

Meteoritic organic material may provide the best perspective on prebiotic chemistry. Meteorites have also been invoked as a source of prebiotic material. This study suggests a caveat to extraterrestrial organic delivery: that prebiotic meteoritic organics were too dilute to promote prebiotic reactions. However, meteoritic material provides building material for endogenous synthesis of prebiotic molecules, such as by hydrolysis of extraterrestrial organic tars, and corrosion of phosphide minerals.

Evidence for deposition of 10 million tonnes of impact spherules across four continents 12,800 y ago

Science.gov (United States)

Wittke, James H.; Weaver, James C.; Bunch, Ted E.; Kennett, James P.; Kennett, Douglas J.; Moore, Andrew M.T.; Hillman, Gordon C.; Tankersly, Kenneth B.; Goodyear, Albert C.; Moore, Christopher R.; Daniel, I. Randolph; Ray, Jack H.; Lopinot, Neal H.; Ferraro, David; Israde-Alcántara, Isabel; Bischoff, James L.; DeCarli, Paul S.; Hermes, Robert E.; Kloosterman, Johan B.; Revay, Zsolt; Howard, George A.; Kimbel, David R.; Kletetschka, Gunther; Nabelek, Ladislav; Lipo, Carl P.; Sakai, Sachiko; West, Allen; Firestone, Richard B.

2013-01-01

Airbursts/impacts by a fragmented comet or asteroid have been proposed at the Younger Dryas onset (12.80 ± 0.15 ka) based on identification of an assemblage of impact-related proxies, including microspherules, nanodiamonds, and iridium. Distributed across four continents at the Younger Dryas boundary (YDB), spherule peaks have been independently confirmed in eight studies, but unconfirmed in two others, resulting in continued dispute about their occurrence, distribution, and origin. To further address this dispute and better identify YDB spherules, we present results from one of the largest spherule investigations ever undertaken regarding spherule geochemistry, morphologies, origins, and processes of formation. We investigated 18 sites across North America, Europe, and the Middle East, performing nearly 700 analyses on spherules using energy dispersive X-ray spectroscopy for geochemical analyses and scanning electron microscopy for surface microstructural characterization. Twelve locations rank among the world’s premier end-Pleistocene archaeological sites, where the YDB marks a hiatus in human occupation or major changes in site use. Our results are consistent with melting of sediments to temperatures >2,200 °C by the thermal radiation and air shocks produced by passage of an extraterrestrial object through the atmosphere; they are inconsistent with volcanic, cosmic, anthropogenic, lightning, or authigenic sources. We also produced spherules from wood in the laboratory at >1,730 °C, indicating that impact-related incineration of biomass may have contributed to spherule production. At 12.8 ka, an estimated 10 million tonnes of spherules were distributed across ∼50 million square kilometers, similar to well-known impact strewnfields and consistent with a major cosmic impact event.

Science, religion, and the search for extraterrestrial intelligence

CERN Document Server

Wilkinson, David

2013-01-01

If the discovery of life elsewhere in the universe is just around the corner, what would be the consequences for religion? Would it represent another major conflict between science and religion, even leading to the death of faith? Some would suggest that the discovery of any suggestion of extraterrestrial life would have a greater impact than even the Copernican and Darwinian revolutions. It is now over 50 years since the first modern scientific papers were published on the search for extraterrestrial intelligence (SETI). Yet the religious implications of this search and possible discovery have never been systematically addressed in the scientific or theological arena. SETI is now entering its most important era of scientific development. New observation techniques are leading to the discovery of extra-solar planets daily, and the Kepler mission has already collected over 1000 planetary candidates. This deluge of data is transforming the scientific and popular view of the existence of extraterrestrial intel...

The Search for Extraterrestrial Intelligence (SETI)

Science.gov (United States)

Tarter, Jill

The search for evidence of extraterrestrial intelligence is placed in the broader astronomical context of the search for extrasolar planets and biomarkers of primitive life elsewhere in the universe. A decision tree of possible search strategies is presented as well as a brief history of the search for extraterrestrial intelligence (SETI) projects since 1960. The characteristics of 14 SETI projects currently operating on telescopes are discussed and compared using one of many possible figures of merit. Plans for SETI searches in the immediate and more distant future are outlined. Plans for success, the significance of null results, and some opinions on deliberate transmission of signals (as well as listening) are also included. SETI results to date are negative, but in reality, not much searching has yet been done.

Root tensile strength assessment of Dryas octopetala L. and implications for its engineering mechanism on lateral moraine slopes (Turtmann Valley, Switzerland)

Science.gov (United States)

Eibisch, Katharina; Eichel, Jana; Dikau, Richard

2015-04-01

Geomorphic processes and properties are influenced by vegetation. It has been shown that vegetation cover intercepts precipitation, enhances surface detention and storage, traps sediment and provides additional surface roughness. Plant roots impact the soil in a mechanical and hydrological manner and affect shear strength, infiltration capacity and moisture content. Simultaneously, geomorphic processes disturb the vegetation development. This strong coupling of the geomorphic and ecologic system is investigated in Biogeomorphology. Lateral moraine slopes are characterized by a variety of geomorphic processes, e. g. sheet wash, solifluction and linear erosion. However, some plant species, termed engineer species, possess specific functional traits which allow them to grow under these conditions and also enable them to influence the frequency, magnitude and even nature of geomorphic processes. For lateral moraine slopes, Dryas octopetala L., an alpine dwarf shrub, was identified as a potential engineer species. The engineering mechanism of D. octopetala, based on its morphological (e.g., growth form) and biomechanical (e.g., root strength) traits, yet remains unclear and only little research has been conducted on alpine plant species. The objectives of this study are to fill this gap by (A) quantifying D. octopetala root tensile strength as an important trait considering anchorage in and stabilization of the slope and (B) linking plant traits to the geomorphic process they influence on lateral moraine slopes. D. octopetala traits were studied on a lateral moraine slope in Turtmann glacier forefield, Switzerland. (A) Root strength of single root threads of Dryas octopetala L. were tested using the spring scale method (Schmidt et al., 2001; Hales et al., 2013). Measurement equipment was modified to enable field measurements of roots shortly after excavation. Tensile strength of individual root threads was calculated and statistically analyzed. First results show that

Beringian Megafaunal Extinctions at ~37 ka B.P.: Do Micrometeorites Embedded in Fossil Tusks and Skulls Indicate an Extraterrestial Precursor to the Younger Dryas Event?

Science.gov (United States)

Hagstrum, J. T.; Firestone, R. B.; West, A.

2009-12-01

Studies of Late Pleistocene megafaunal fossils and their ancient DNA from Beringia (eastern Siberia, Alaska, and the emerged Bering Strait) indicate sharp declines in steppe bison population diversity and horse body size, extinction of the Alaskan wild ass, and local extinctions of brown bear and woolly mammoth genetic lines beginning at about 37 ka B.P. Beringia is also well known for its remarkably preserved Late Pleistocene frozen animal mummies. 14C ages of these mummies are bimodally distributed, having peaks coincident with the earlier ~37 ka B.P., and ~13 ka B.P. Younger Dryas, onset extinction events. Associated with the ~37 ka B.P. event are, for example, the Berezovka mammoth, headless Selerikan horse, steppe bison “Blue Babe”, and baby mammoths “Dima” and “Lyuba”. Analyses of these and other mummies indicate that they died instantly, in mostly healthy condition, with gut contents and high fat reserves indicative of a late summer to autumn season. An assortment of uneaten limbs and other body parts from a variety of species have also been found. Uniformitarian death scenarios inadequately account for the lack of evidence of normal predation and scavenging. Extensive internal injuries (e.g. large bone fractures, hemorrhaging) and apparent rapid burial of the mummies also indicate that something truly unusual happened at the time of these extinction events. We have discovered what appear to be micrometeorites embedded in seven Alaskan mammoth tusks and a Siberian bison skull acquired from commercial sources. 14C ages for five of these fossils have a weighted mean age of 33 ± 2 ka B.P. Laser ablation ICP-MS and XRF analyses of the particles indicate high Fe contents with compositions enriched in Ni and depleted in Ti, similar to Fe meteorites and unlike any natural terrestrial sources. Microprobe analyses of a Fe-Ni sulfide grain from tusk 2 also show that it contains between 3 and 20 weight percent Ni. SEM images and XRF analyses of a bison

Curating NASA's Future Extraterrestrial Sample Collections: How Do We Achieve Maximum Proficiency?

Science.gov (United States)

McCubbin, Francis; Evans, Cynthia; Zeigler, Ryan; Allton, Judith; Fries, Marc; Righter, Kevin; Zolensky, Michael

2016-01-01

The Astromaterials Acquisition and Curation Office (henceforth referred to herein as NASA Curation Office) at NASA Johnson Space Center (JSC) is responsible for curating all of NASA's extraterrestrial samples. Under the governing document, NASA Policy Directive (NPD) 7100.10E "Curation of Extraterrestrial Materials", JSC is charged with "The curation of all extraterrestrial material under NASA control, including future NASA missions." The Directive goes on to define Curation as including "... documentation, preservation, preparation, and distribution of samples for research, education, and public outreach." Here we describe some of the ongoing efforts to ensure that the future activities of the NASA Curation Office are working towards a state of maximum proficiency.

Funding the Search for Extraterrestrial Intelligence with a Lottery Bond

OpenAIRE

Haqq-Misra, Jacob

2013-01-01

I propose the establishment of a SETI Lottery Bond to provide a continued source of funding for the search for extraterrestrial intelligence (SETI). The SETI Lottery Bond is a fixed rate perpetual bond with a lottery at maturity, where maturity occurs only upon discovery and confirmation of extraterrestrial intelligent life. Investors in the SETI Lottery Bond purchase shares that yield a fixed rate of interest that continues indefinitely until SETI succeeds---at which point a random subset of...

Detailed Sea Level Record from Barbados Spanning 13,000 to 11,000 Years Before Present

Science.gov (United States)

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

2013-12-01

Th/U dated reef-crest corals (Acropora palmata) obtained from new Barbados offshore drill cores provide a local sea level reconstruction in unprecedented detail. The time interval, 13,000 to 11,000 years before present (BP), spans the well-studied Younger Dryas pollen zone, a period that has given rise to more than three decades of sensational climate interpretations and popular press. Widely described as a time when Earth's climate reverted to "glacial-like conditions" the various hypotheses that attempt to explain the "cause" of the Younger Dryas climate event have their staunch supporters as well as their critics but there remains little consensus. The Barbados sea level record for this time interval shows that sea level continued to rise during the Younger Dryas, albeit at a slower rate than prior to 13,000 or following 11,000 years BP. The decrease in the rate of sea level rise can simply be explained by the slow expansion of the Fennoscandian Ice Sheet beginning 12,800 years BP followed by its faster demise contributing to a period of rapid sea level increase known as Melt Water Pulse 1B. We calculate the ice volume history of the Fennoscandian Ice Sheet and it compares favorably to the moraine history and ice models. The Younger Dryas climate event is most often defined by the rapid shifts in atmospheric proxies measured in ice cores from Greenland. The ice core proxies shift into and out of the Younger Dryas climate event in only a few years to a few decades. Abrupt shifts in the climate state associated with the onset and termination of the Younger Dryas as revealed in Greenland Ice cores are not expressed in the smooth Barbados deglacial sea level record. We make the case that these Greenland atmospheric records mark regional atmospheric frontal shifts and changes in air mass sources over an ice sheet that largely did not participate in the deglaciation or sea level change. As proposed decades ago, the warming of the North Atlantic between 14,000 and 13

Pulleniatina Minimum Events in the Andaman Sea (NE Indian Ocean): Implications for winter monsoon and thermocline changes

Digital Repository Service at National Institute of Oceanography (India)

Sijinkumar, A.V.; Nath, B.N.; Possnert, G.; Aldahan, A.

abundance, and which matches well with the Pacific records influenced by the Kuroshio Current. Additionally, two significant minimum events of P. obliquiloculata are also seen during the Younger Dryas (YD) and late Last Glacial Maximum (LGM, 20-18 cal ka... (LGM, 20-18 cal ka BP, Younger Dryas (YD, 13-10.5 cal ka BP) and late Holocene (4.5-3 cal ka BP). Northern core SK 168 shows distinctive minimum events and the intensity of variation reduces towards the south. The Holocene PME is a little longer...

Extraterrestrial seismology

CERN Document Server

Tong, Vincent C H

2015-01-01

Seismology is a highly effective tool for investigating the internal structure of the Earth. Similar techniques have also successfully been used to study other planetary bodies (planetary seismology), the Sun (helioseismology), and other stars (asteroseismology). Despite obvious differences between stars and planetary bodies, these disciplines share many similarities and together form a coherent field of scientific research. This unique book takes a transdisciplinary approach to seismology and seismic imaging, reviewing the most recent developments in these extraterrestrial contexts. With contributions from leading scientists, this timely volume systematically outlines the techniques used in observation, data processing, and modelling for asteroseismology, helioseismology, and planetary seismology, drawing comparisons with seismic methods used in geophysics. Important recent discoveries in each discipline are presented. With an emphasis on transcending the traditional boundaries of astronomy, solar, planetary...

Psycholinguistics and the Search for Extraterrestrial Intelligence

Directory of Open Access Journals (Sweden)

Lidija Krotenko

2017-09-01

Full Text Available The author of the article reveals the possibilities of psycholinguistics in the identifi cation and interpretation of languages and texts of Alien Civilizations. The author combines modern interdisciplinary research in psycholinguistics with the theory “Evolving Matter” proposed by Oleg Bazaluk and concludes that the identifi cation of languages and texts of Alien Civilizations, as well as the communication of terrestrial civilization with Extraterrestrial Intelligence, is in principle possible. To that end, it is necessary to achieve the required level of the modeling of neurophilosophy and to include these achievements of modern psycholinguistics studies: а language acquisition; b language comprehension; c language production; d second language acquisition. On the one hand, the possibilities of neurophilosophy to accumulate and model advanced neuroscience research; on the other hand, highly specialized psycholinguistic studies in language evolution are able to provide the communication of terrestrial civilization with Extraterrestrial Intelligence.

Anthropomorphism in the search for extra-terrestrial intelligence - The limits of cognition?

Science.gov (United States)

Bohlmann, Ulrike M.; Bürger, Moritz J. F.

2018-02-01

The question "Are we alone?" lingers in the human mind since ancient times. Early human civilisations populated the heavens above with a multitude of Gods endowed with some all too human characteristics - from their outer appearance to their innermost motivations. En passant they created thereby their own cultural founding myths on which they built their understanding of the world and its phenomena and deduced as well rules for the functioning of their own society. Advancing technology has enabled us to conduct this human quest for knowledge with more scientific means: optical and radio-wavelengths are being monitored for messages by an extra-terrestrial intelligence and active messaging attempts have also been undertaken. Scenarios have been developed for a possible detection of extra-terrestrial intelligence and post-detection guidelines and protocols have been elaborated. The human responses to the whole array of questions concerning the potential existence, discovery of and communication/interaction with an extra-terrestrial intelligence share as one clear thread a profound anthropomorphism, which ascribes classical human behavioural patterns also to an extra-terrestrial intelligence in much the same way as our ancestors attributed comparable conducts to mythological figures. This paper aims at pinpointing this thread in a number of classical reactions to basic questions related to the search for extra-terrestrial intelligence. Many of these reactions are based on human motives such as curiosity and fear, rationalised by experience and historical analogy and modelled in the Science Fiction Culture by literature and movies. Scrutinising the classical hypothetical explanations of the Fermi paradox under the angle of a potentially undue anthropomorphism, this paper intends to assist in understanding our human epistemological limitations in the search for extra-terrestrial intelligence. This attempt is structured into a series of questions: I. Can we be alone? II

The Problem of Extraterrestrial Civilizations and Extrasolar Planets

Science.gov (United States)

Mickaelian, A. M.

2015-07-01

The problem of extraterrestrial intelligence is the best example of multidisciplinary science. Here philosophy and religion, astronomy, radiophysics, spectrography, space flights and astronautics, geology and planetology, astroecology, chemistry and biology, history and archaeology, psychology, sociology, linguistics, diplomacy, UFOs and peculiar phenomena are involved. Among these many-sided studies, astronomers have probably displayed the most progress by discovering thousands of extrasolar planets. At present, a number of search programs are being accomplished, including those with space telescopes, and planets in so-called "habitable zone" are considered as most important ones, for which various orbital and physical parameters are being calculated. As the discovery of extraterrestrial life is the final goal, a special attention is given to Earth-like planets, for the discovery of which most sensitive technical means are necessary.

Problems with the Younger Dryas Boundary (YDB) Impact Hypothesis

Science.gov (United States)

Boslough, M.

2009-12-01

One breakthrough of 20th-century Earth science was the recognition of impacts as an important geologic process. The most obvious result is a crater. There are more than 170 confirmed terrestrial impact structures with a non-uniform spatial distribution suggesting more to be found. Many have been erased by tectonics and erosion. Deep water impacts do not form craters, and craters in ice sheets disappear when the ice melts. There is growing speculation that such hidden impacts have caused frequent major environmental events of the Holocene, but this is inconsistent with the astronomically-constrained population of Earth-crossing asteroids. Impacts can have consequences much more significant than excavation of a crater. The K/T boundary mass extinction is attributed to the environmental effects of a major impact, and some researchers argue that other extinctions, abrupt climate changes, and even civilization collapses have resulted from impacts. Nuclear winter models suggest that 2-km diameter asteroids exceed a "global catastrophe threshold" by injecting sufficient dust into the stratosphere to cause short-term climate changes, but would not necessarily collapse most natural ecosystems or cause mass extinctions. Globally-catastrophic impacts recur on timescales of about one million years. The 1994 collision of Comet Shoemaker-Levy 9 with Jupiter led us recognize the significance of terrestrial airbursts caused by objects exploding violently in Earth’s atmosphere. We have invoked airbursts to explain rare forms of non-volcanic glasses and melts by using high-resolution computational models to improve our understanding of atmospheric explosions, and have suggested that multiple airbursts from fragmented impactors could be responsible for regional effects. Our models have been cited in support of the widely-publicized YDB impact hypothesis. Proponents claim that a broken comet exploded over North America, with some fragments cratering the Laurentide Ice Sheet. They suggest an abrupt climate change caused by impact-triggered meltwater forcing, along with massive wildfires, resulted in megafaunal extinctions and collapse of the Clovis culture. We argue that the physics of fragmentation, dispersion, and airburst is not consistent with the hypothesis; that observations are no more compatible with impact than with other causes; and that the probability of the scenario is effectively nil. Moreover, millennial-scale climate events are far more frequent than catastrophic impacts, and pose a much greater threat to humanity. Sandia is a multiprogram laboratory operated by Sandia Corp, a Lockheed Martin Company, for the US DOE under Contract DE-AC04-94AL85000. Probability density for largest asteroid impact since Last Glacial Maximum based on power-law size distribution. Comets are orders of magnitude less likely. Grazing trajectory or recent fragmentation further reduces probability.

Younger Dryas Boundary (YDB) impact : physical and statistical impossibility.

Energy Technology Data Exchange (ETDEWEB)

Boslough, Mark Bruce Elrick

2010-08-01

The YDB impact hypothesis of Firestone et al. (2007) is so extremely improbable it can be considered statistically impossible in addition to being physically impossible. Comets make up only about 1% of the population of Earth-crossing objects. Broken comets are a vanishingly small fraction, and only exist as Earth-sized clusters for a very short period of time. Only a small fraction of impacts occur at angles as shallow as proposed by the YDB impact authors. Events that are exceptionally unlikely to take place in the age of the Universe are 'statistically impossible'. The size distribution of Earth-crossing asteroids is well-constrained by astronomical observations, DoD satellite bolide frequencies, and the cratering record. This distribution can be transformed to a probability density function (PDF) for the largest expected impact of the past 20,000 years. The largest impact of any kind expected over the period of interest is 250 m. Anything larger than 2 km is exceptionally unlikely (probability less than 1%). The impact hypothesis does not rely on any sound physical model. A 4-km diameter comet, even if it fragmented upon entry, would not disperse or explode in the atmosphere. It would generate a crater about 50 km in diameter with a transient cavity as deep as 10 km. There is no evidence for such a large, young crater associated with the YDB. There is no model to suggest that a comet impact of this size is capable of generating continental-wide fires or blast damage, and there is no physical mechanism that could cause a 4-km comet to explode at the optimum height of 500 km. The highest possible altitude for a cometary optimum height is about 15 km, for a 120-m diameter comet. To maximize blast and thermal damage, a 4-km comet would have to break into tens of thousands fragments of this size and spread out over the entire continent, but that would require lateral forces that greatly exceed the drag force, and would not conserve energy. Airbursts are decompression explosions in which projectile material reaches high temperature but not high pressure states. Meteoritic diamonds would be vaporized. Nanodiamonds at the YDB are not evidence for an airburst or for an impact.

L factor: hope and fear in the search for extraterrestrial intelligence

Science.gov (United States)

Rubin, Charles T.

2001-08-01

The L factor in the Drake equation is widely understood to account for most of the variance in estimates of the number of extraterrestrial intelligences that might be contacted by the search for extraterrestrial intelligence (SETI). It is also among the hardest to quantify. An examination of discussions of the L factor in the popular and technical SETI literature suggests that attempts to estimate L involve a variety of potentially conflicting assumptions about civilizational lifespan that reflect hopes and fears about the human future.

Anthropogenic Origin of Siliceous Scoria Droplets from Pleistocene and Holocene Archeaological Sites in Northern Syria

DEFF Research Database (Denmark)

Thy, Peter; Willcox, George; Barfod, Gry

2015-01-01

Siliceous scoria droplets, measuring from 1 to 10 mm, from one late Pleistocene and four early Holocene archaeological sites in northern Syria are compared to similar droplets previously suggested to be the result of a cosmic impact at the onset of the Younger Dryas global cooling event. The !ndi......Siliceous scoria droplets, measuring from 1 to 10 mm, from one late Pleistocene and four early Holocene archaeological sites in northern Syria are compared to similar droplets previously suggested to be the result of a cosmic impact at the onset of the Younger Dryas global cooling event...

Extraterrestrial Intelligence: What Would it Mean?

Science.gov (United States)

Impey, Chris

2015-04-01

Results from NASA's Kepler mission imply a hundred million Earth-like habitable worlds in the Milky Way galaxy, many of which formed billions of years before the Earth. Each of these worlds is likely to have all of the ingredients needed for biology. The real estate of time and space for the evolution of intelligent life is formidable, begging the question of whether or not we are alone in the universe. The implications of making contact have been explored extensively in science fiction and the popular culture, but less frequently in the serious scientific literature. Astronomers have carried out searches for extraterrestrial intelligence for over half a century, with no success so far. In practice, it is easier to search for alien technology than to discern intelligence of unknown function and form. In this talk, the modes of technology that can currently be detected are summarized, along with the implications of a timing argument than any detected civilization is likely to be much more advanced than ours. Fermi's famous question ``Where Are They?'' is as well posed now as it was sixty years ago. The existence of extraterrestrial intelligence would have profound practical, cultural, and religious implications for humanity.

Information theory, animal communication, and the search for extraterrestrial intelligence

Science.gov (United States)

Doyle, Laurance R.; McCowan, Brenda; Johnston, Simon; Hanser, Sean F.

2011-02-01

We present ongoing research in the application of information theory to animal communication systems with the goal of developing additional detectors and estimators for possible extraterrestrial intelligent signals. Regardless of the species, for intelligence (i.e., complex knowledge) to be transmitted certain rules of information theory must still be obeyed. We demonstrate some preliminary results of applying information theory to socially complex marine mammal species (bottlenose dolphins and humpback whales) as well as arboreal squirrel monkeys, because they almost exclusively rely on vocal signals for their communications, producing signals which can be readily characterized by signal analysis. Metrics such as Zipf's Law and higher-order information-entropic structure are emerging as indicators of the communicative complexity characteristic of an "intelligent message" content within these animals' signals, perhaps not surprising given these species' social complexity. In addition to human languages, for comparison we also apply these metrics to pulsar signals—perhaps (arguably) the most "organized" of stellar systems—as an example of astrophysical systems that would have to be distinguished from an extraterrestrial intelligence message by such information theoretic filters. We also look at a message transmitted from Earth (Arecibo Observatory) that contains a lot of meaning but little information in the mathematical sense we define it here. We conclude that the study of non-human communication systems on our own planet can make a valuable contribution to the detection of extraterrestrial intelligence by providing quantitative general measures of communicative complexity. Studying the complex communication systems of other intelligent species on our own planet may also be one of the best ways to deprovincialize our thinking about extraterrestrial communication systems in general.

A reindeer footprint in a drilling core from the Allerød-Bølling age succession of Lille Slotseng basin, south-eastern Jylland, Denmark

DEFF Research Database (Denmark)

Noe-Nygaard, Nanna; Milàn, Jesper; Hede, Mikkel Ulfeldt

2005-01-01

,000 to around 8,000 cal yr BP years. The basin sedimentation starts with old melt water deposits just below the Bølling Interstadial (GI 1-e), followed by older Dryas (GI 1-d), Allerød, (GI 1-c, 1-b, 1-a) and Younger Dryas (GS 1) which terminates the Late Glacial succession. Preboreal algal gyttja and near...

SETI pioneers scientists talk about their search for extraterrestrial intelligence

CERN Document Server

Swift, David W.

1990-01-01

Why did some scientists decide to conduct a search for extraterrestrial intelligence (SETI)? What factors in their personal development predisposed them to such a quest? What obstacles did they encounter along the way? David Swift interviewed the first scientists involved in the search & offers a fascinating overview of the emergence of this modern scientific endeavor. He allows some of the most imaginative scientific thinkers of our time to hold forth on their views regarding SETI & extraterrestrial life & on how the field has developed. Readers will react with a range of opinions as broad as those concerning the likelihood of success in SETI itself. ''A goldmine of original information.''

Toward a new cosmic consciousness: Psychoeducational aspects of contact with extraterrestrial civilizations

Science.gov (United States)

De la Torre, Gabriel G.

2014-02-01

This study presents a new approach to the concept of cosmic consciousness integrated in current neuroscience knowledge and discusses implications for the search for extraterrestrial intelligence. It also examines different aspects related to consciousness and how it may play a key role in the understanding of the search for extraterrestrial intelligence and life in the Universe and its implications. Subjects (n=116) were college students from Spain, the United States, and Italy. Subjects responded to a questionnaire comprising five different sections: (A) religious beliefs, (B) environment and general opinion, (C) astronomy, (D) contact, and (E) attention and perception. The results showed the importance of several modular aspects that affect Space awareness in humans. Preliminary results are discussed with regard to current neuroscience, factor analysis, and possible implications for the understanding of contact with extraterrestrial intelligence. The roles of education, new search strategies, and possible contact scenarios are also discussed.

Who owns the Moon? extraterrestrial aspects of land and mineral resources ownership

CERN Document Server

Pop, Virgiliu

2008-01-01

This work investigates the permissibility and viability of property rights on the celestial bodies, particularly the extraterrestrial aspects of land and mineral resources ownership. In lay terms, it aims to find an answer to the question "Who owns the Moon?" After critically analyzing and dismantling with legal arguments the trivial issue of sale of extraterrestrial real estate, the book addresses the apparent silence of the law in the field of landed property in outer space, scrutinizing whether the factual situation on the extraterrestrial realms calls for legal regulations. The legal status of asteroids and the relationship between appropriation under international law and civil law appropriation are duly examined, as well as different property patterns – such as the commons regime, the Common Heritage of the Mankind, and the Frontier paradigm. Virgiliu Pop is one of world's specialists in the area of space property rights. A member of the International Institute of Space Law, Virgiliu has authored seve...

Tracers of the Extraterrestrial Component in Sediments and Inferences for Earth's Accretion History

Science.gov (United States)

Kyte, Frank T.

2003-01-01

The study of extraterrestrial matter in sediments began with the discovery of cosmic spherules during the HMS Challenger Expedition (1873-1876), but has evolved into a multidisciplinary study of the chemical, physical, and isotopic study of sediments. Extraterrestrial matter in sediments comes mainly from dust and large impactors from the asteroid belt and comets. What we know of the nature of these source materials comes from the study of stratospheric dust particles, cosmic spherules, micrometeorites, meteorites, and astronomical observations. The most common chemical tracers of extraterrestrial matter in sediments are the siderophile elements, most commonly iridium and other platinum group elements. Physical tracers include cosmic and impact spherules, Ni-rich spinels, meteorites, fossil meteorites, and ocean-impact melt debris. Three types of isotopic systems have been used to trace extraterrestrial matter. Osmium isotopes cannot distinguish chondritic from mantle sources, but provide a useful tool in modeling long-term accretion rates. Helium isotopes can be used to trace the long-term flux of the fine fraction of the interplanetary dust complex. Chromium isotopes can provide unequivocal evidence of an extraterrestrial source for sediments with high concentrations of meteoritic Cr. The terrestrial history of impacts, as recorded in sediments, is still poorly understood. Helium isotopes, multiple Ir anomalies, spherule beds, and craters all indicate a comet shower in the late Eocene. The Cretaceous-Tertiary boundary impact event appears to have been caused by a single carbonaceous chondrite projectile, most likely of asteroid origin. Little is known of the impact record in sediments from the rest of the Phanerozoic. Several impact deposits are known in the Precambrian, including several possible mega-impacts in the Early Archean.

The weak force and SETH: The search for Extra-Terrestrial Homochirality

Science.gov (United States)

MacDermott, Alexandra J.

1996-07-01

We propose that a search for extra-terrestrial life can be approached as a Search for Extra-Terrestrial Homochirality-SETH. Homochirality is probably a pre-condition for life, so a chiral influence may be required to get life started. We explain how the weak force mediated by the Z0 boson gives rise to a small parity-violating energy difference (PVED) between enantiomers, and discuss how the resulting small excess of the more stable enantiomer may be amplified to homochirality. Titan and comets are good places to test for emerging pre-biotic homochirality, while on Mars there may be traces of homochirality as a relic of extinct life. Our calculations of the PVED show that the natural L-amino acids are indeed more stable than their enantiomers, as are several key D-sugars and right-hand helical DNA. Thiosubstituted DNA analogues show particularly large PVEDs. L-quartz is also more stable than D-quartz, and we believe that further crystal counts should be carried out to establish whether reported excesses of L quartz are real. Finding extra-terrestrial molecules of the same hand as on Earth would lend support to the universal chiral influence of the weak force. We describe a novel miniaturized space polarimeter, called the SETH Cigar, which we hope to use to detect optical rotation on other planets. Moving parts are avoided by replacing the normal rotating polarizer by multiple fixed polarizers at different angles as in the eye of the bee. Even if we do not find the same hand as on Earth, finding extra-terrestrial optical rotation would be of enormous importance as it would still be the homochiral signature of life.

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

Science.gov (United States)

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

2000-01-01

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

[An encounter with extraterrestrial intelligence].

Science.gov (United States)

Hisabayashi, Hisashi

2003-12-01

It is much easier to find extraterrestrial intelligence than to detect simple organisms living on other planets. However, it is hard to communicate with such intelligence without the mutual understanding of inter-stellar communication protocol. The radio SETI (The Search for Extra-Terrestrial Intelligence) was initiated with the pioneering work of F. Drake in 1960, one year after the historical SETI paper by Cocconi and Morrison. This talk explains that SETI evolves with two bases of science; the understanding of our universe and the development of technology. Since SETI has had strong connection with radio astronomy from its early beginning, the impacts of radio astronomical findings and technological breakthrough can be seen in many aspects of the SETI history. Topics of this talk include the detection of microwave 3 K background radiation in the universe. Interstellar atomic and molecular lines found in radio-wave spectra provide the evidence of pre-biotic chemical evolution in such region. Radio telescope imaging and spectral technique are closely associated with methodology of SETI. Topics of the talk extend to new Allen Telescope Array and projected Square Kilometer Array. Recent optical SETI and the discoveries of extra solar planets are also explained. In the end, the recent understanding of our universe is briefly introduced in terms of matter, dark matter and dark energy. Even our understanding of the universe has been evolutionarily revolved and accumulated after 1960, we must recognize that our universe is still poorly understood and that astronomy and SETI are required to proceed hand in hand.

Extraterrestrial Radiation Chemistry and Molecular Astronomy

Science.gov (United States)

Hudson, Reggie L.; Moore, Marla H.

2009-01-01

Astronomical observations of both solar system and interstellar regions have revealed a rich chemical inventory that includes most classes of organic molecules and selected inorganics. For example, gas-phase ethylene glycol and SOz have been observed by astronomers, while solidphase detections include OCS, H2O2 , and the cyanate anion.' All of these are found in environments that are, by earthly standards, exceedingly hostile: temperatures of 10 - 100 K, miniscule densities, and near-ubiquitous ionizing-radiation fields. Beyond the simplest chemical species, these conditions have made it difficult-to-impassible to account for the observed molecular abundances using gas-phase chemistry, suggesting solid-phase reactions play an important role. In extraterrestrial environments, cosmic rays, UV photons, and magnetospheric radiation all drive chemical reactions, even at cryogenic temperatures. To study this chemistry, radiation astrochemists conduct experiments on icy materials, frozen under vacuum and exposed to sources such as keV electrons and MeV protons. Compositional changes usually are followed with IR spectroscopy and, in selected cases, more-sensitive mass-spectral techniques. This talk will review some recent results on known and suspected extraterrestrial molecules and ions. Spectra and reaction pathways will be presented, and predictions made for interstellar chemistry and the chemistry of selected solar system objects. Some past radiation-chemical contributions, and future needs, will be explored.

[Extraterrestrial influences on health and disease].

Science.gov (United States)

Sitar, J

1994-02-14

As to extraterrestrial influences on man in health and disease so far only the effect of the sun and moon are known. This concerns the effect of solar radiation of different wavelengths and the effect of corpuscular solar radiation which has an impact on the condition of the terrestrial magnetic field and electric conditions in the atmosphere. Moreover there is also a question of important influences of gravitation (tides). Here the influence of the position of the moon in relation to the connecting line between sun and earth is involved. In the course of the synodic month (from new moon to the next new moon) a semilunar periodicity of different medical and geomagnetic indicators as well as meteorological ones plays a part. Based on his own research and that of others the author reaches the conclusion that extraterrestrial and terrestrial influences are interrelated and exert a mutual influence on each other and that it is not sensible to separate them strictly. Investigation of all the mentioned influences is important not only for biomedical prognosis but also for basic geophysical and meteorological research. Perspectively it would be useful to plan model experiments. The author feels it is his duty to refuse publication of different horoscopes in the mass media, whatever the intention. In the lay public this may lead to popularization of astrology which has nothing in common with serious research.

Finding Extraterrestrial Life Using Ground-based High-dispersion Spectroscopy

NARCIS (Netherlands)

Snellen, I.A.G.; Kok, R.; Poole, le R.S.; Brogi, M.; Birkby, J.L.

2013-01-01

Exoplanet observations promise one day to unveil the presence of extraterrestrial life. Atmospheric compounds in strong chemical disequilibrium would point to large-scale biological activity just as oxygen and methane do in the Earth's atmosphere. The cancellation of both the Terrestrial Planet

The weak force and SETH: The search for Extra-Terrestrial Homochirality

International Nuclear Information System (INIS)

MacDermott, A.J.

1996-01-01

We propose that a search for extra-terrestrial life can be approached as a Search for Extra-Terrestrial Homochirality emdash SETH. Homochirality is probably a pre-condition for life, so a chiral influence may be required to get life started. We explain how the weak force mediated by the Z 0 boson gives rise to a small parity-violating energy difference (PVED) between enantiomers, and discuss how the resulting small excess of the more stable enantiomer may be amplified to homochirality. Titan and comets are good places to test for emerging pre-biotic homochirality, while on Mars there may be traces of homochirality as a relic of extinct life. Our calculations of the PVED show that the natural L-amino acids are indeed more stable than their enantiomers, as are several key D-sugars and right-hand helical DNA. Thiosubstituted DNA analogues show particularly large PVEDs. L-quartz is also more stable than D-quartz, and we believe that further crystal counts should be carried out to establish whether reported excesses of L quartz are real. Finding extra-terrestrial molecules of the same hand as on Earth would lend support to the universal chiral influence of the weak force. We describe a novel miniaturized space polarimeter, called the SETH Cigar, which we hope to use to detect optical rotation on other planets. Moving parts are avoided by replacing the normal rotating polarizer by multiple fixed polarizers at different angles as in the eye of the bee. Even if we do not find the same hand as on Earth, finding extra-terrestrial optical rotation would be of enormous importance as it would still be the homochiral signature of life. copyright 1996 American Institute of Physics

The Societal Impact of Extraterrestrial Life: The Relevance of History and the Social Sciences

Science.gov (United States)

Dick, Steven J.

This chapter reviews past studies on the societal impact of extraterrestrial life and offers four related ways in which history is relevant to the subject: the history of impact thus far, analogical reasoning, impact studies in other areas of science and technology, and studies on the nature of discovery and exploration. We focus particularly on the promise and peril of analogical arguments, since they are by necessity widespread in the field. This chapter also summarizes the relevance of the social sciences, particularly anthropology and sociology, and concludes by taking a closer look at the possible impact of the discovery of extraterrestrial life on theology and philosophy. In undertaking this study we emphasize three bedrock principles: (1) we cannot predict the future; (2) society is not monolithic, implying many impacts depending on religion, culture and worldview; (3) the impact of any discovery of extraterrestrial life is scenario-dependent.

Post-Clovis survival of American Mastodon in the southern Great Lakes Region of North America

Science.gov (United States)

Woodman, N.; Beavan, Athfield N.

2009-01-01

The end of the Pleistocene in North America was marked by a wave of extinctions of large mammals, with the last known appearances of many species falling between ca. 11,000-10,000??14C yr BP. Temporally, this period overlaps with the Clovis Paleoindian cultural complex (11,190-10,530??14C yr BP) and with sudden climatic changes that define the beginning of the Younger Dryas chronozone (ca. 11,000-10,000??14C yr BP), both of which have been considered as potential proximal causes of this extinction event. Radiocarbon dating of enamel and filtered bone collagen from an extinct American Mastodon (Mammut americanum) from northern Indiana, USA, by accelerator mass spectrometer yielded direct dates of 10,055 ?? 40??14C yr BP and 10,032 ?? 40??14C yr BP, indicating that the animal survived beyond the Clovis time period and into the late Younger Dryas. Although the late survival of this species in mid-continental North America does not remove either humans or climatic change as contributing causes for the late Pleistocene extinctions, neither Clovis hunters nor the climatic perturbations initiating the Younger Dryas chronozone were immediately responsible for driving mastodons to extinction. ?? 2009 University of Washington.

Post-Clovis survival of American Mastodon in the southern Great Lakes Region of North America

Science.gov (United States)

Woodman, Neal; Beavan Athfield, Nancy

2009-11-01

The end of the Pleistocene in North America was marked by a wave of extinctions of large mammals, with the last known appearances of many species falling between ca. 11,000-10,000 14C yr BP. Temporally, this period overlaps with the Clovis Paleoindian cultural complex (11,190-10,530 14C yr BP) and with sudden climatic changes that define the beginning of the Younger Dryas chronozone (ca. 11,000-10,000 14C yr BP), both of which have been considered as potential proximal causes of this extinction event. Radiocarbon dating of enamel and filtered bone collagen from an extinct American Mastodon ( Mammut americanum) from northern Indiana, USA, by accelerator mass spectrometer yielded direct dates of 10,055 ± 40 14C yr BP and 10,032 ± 40 14C yr BP, indicating that the animal survived beyond the Clovis time period and into the late Younger Dryas. Although the late survival of this species in mid-continental North America does not remove either humans or climatic change as contributing causes for the late Pleistocene extinctions, neither Clovis hunters nor the climatic perturbations initiating the Younger Dryas chronozone were immediately responsible for driving mastodons to extinction.

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

Science.gov (United States)

Geller, Harold A.

2014-01-01

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

Radiocarbon datings and glacial striae from the innar part of Boknfjord area, South Norway

International Nuclear Information System (INIS)

Anundsen, K.

1977-01-01

Whale bones overlain by moraine at Borgoey island have been dated to 12,380+-150 B.P. At Tveit, further east, whale bones overlain by littoral material were dated to 11,970+-100 B.P. These datings, together with the glacial striae in the area, show that Borgoe was covered by ice during a glacial advance at about Older Dryas Chronozone, while Tveit was not, and that a calving bay existed in the inner part of the Boknfjord area at the same time. At the mouth of Vindafjord, east of Tveit, and 3-4 km outside terminal moraines of Younger Dryas age, shells overlain by ground moraine were dated to 11,630+-100 B.P. This shows that the ice front in an early phase of the Younger Dryas glacial advance was situated at least 3-4 km beyond the pronounced Ra moraines in Vindafjord. The main trend of the shore line displacement between 12,000 and 9,500 B.P., based upon the whale bones and earlier investigations, can be established. (Auth.)

Late glacial vegetation and climate changes in the high mountains of Bulgaria (Southeast Europe)

International Nuclear Information System (INIS)

Bozilova, E.D.; Tonkov, S.B.

2005-01-01

Full text: The Late glacial vegetation history in the high mountains of Southern Bulgaria (Rila, Pirin, Western Rhodopes) is reconstructed by means of pollen analysis, plant macrofossils and radiocarbon dating of sediments from lakes and peat-bogs located between 1300 and 2200 m a.s.l. The vegetation response to the climate fluctuations after 13000 14 C yrs. BP in the Rila Mountains is bound for the first time to a detailed chronological framework. Two stadial and one interstadial phases are delimited analogous with the Oldest Dryas-Bolling/Allerod-Younger Dryas cycle for Western Europe. During the stadials mountain-steppe vegetation composed of Artemisia, Chenopodiaceae, Poaceae and other cold-resistant herbs dominated at high elevation with sparse stands of Pinus, Betula, and shrubland of Juniperus and Ephedra. The climate improvement in the interstadial resulted in the initial spread of deciduous and coniferous trees (Quercus, Tilia, Corylus, Carpinus, Abies, Picea) from their local refugia below 1000 m. The palaeoecological record from the climate deterioration during the Younger Dryas is documented in thin sections of the cores investigated. (author)

Study of extraterrestrial material by means of a high sensitive mass spectrometer, 1

International Nuclear Information System (INIS)

Arai, O.; Kaneko, K.; Kobayashi, K.; Shimamura, T.

1975-01-01

In this report it is described about a high sensitive mass spectrometer for measurement of isotopic abundance of extraterrestrial material. Detecting isotopic anomalies in extraterrestrial matter induced by cosmic ray or solar wind irradiation, we can obtain many informations about interplanetary and/or intersteller space. For this purpose we reform the mass spectrometer of Low Energy Physics Division of INS to improve the sensitivity and the resolution. In section I--VI some improvements of the mass spectrometer (vacuum system, ion source, collector etc.) are described. In section VII--X newly developed ion counting system is discussed. (auth.)

The Role of Extraterrestrial Materials in the Origin of Life

Science.gov (United States)

Sandford, Scott A.

2016-01-01

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

Insights from Cyanobacterial Genomes for the Development of Extraterrestrial Photoautotrophic Biotechnologies

Science.gov (United States)

Brown, I. I.; Bryant, D. A.; Tringe, S. G.; Malley, K.; Sosa, O.; Sarkisova, S. A.; Garrison, D. H.; McKay, D. S.

2010-04-01

Using genomic and metagenomic analysis, Fe-tolerant cyanobacterial species with a large and diverse set of stress-tolerant genes, were identified as prime candidates for in situ resource utilization in a biogeoreactor at extraterrestrial outposts.

Extraterrestrial cause for the Cretaceous-Tertiary extinction

International Nuclear Information System (INIS)

Alvarez, L.W.; Alvarez, W.; Asaro, F.; Michel, H.V.

1980-01-01

Platinum metals are depleted in the earth's crust relative to their cosmic abundance; concentrations of these elements in deep-sea sediments may thus indicate influxes of extraterrestrial material. Deep-sea limestones exposed in Italy, Denmark, and New Zealand show iridium increases of about 30, 160, and 20 times, respectively, above the background level at precisely the time of the Cretaceous-Tertiary extinctions, 65 million years ago. Reasons are given to indicate that this iridium is of extraterrestrial origin, but did not come from a nearby supernova. A hypothesis is suggested which accounts for the extinctions and the iridium observations. Impact of a large earth-crossing asteroid would inject about 60 times the object's mass into the atmosphere as pulverized rock; a fraction of this dust would stay in the stratosphere for several years and be distributed worldwide. The resulting darkness would suppress photosynthesis, and the expected biological consequences match quite closely the extinctions observed in the paleontological record. One prediction of this hypothesis has been verified: the chemical composition of the boundary clay, which is thought to come from the stratospheric dust, is markedly different from that of clay mixed with the Cretaceous and Tertiary limestones, which are chemically similar to each other. Four different independent estimates of the diameter of the asteroid give values that lie in the range 10 +- 4 kilometers

Religions and extraterrestrial life how will we deal with it?

CERN Document Server

Weintraub, David A

2014-01-01

In the twenty-first century, the debate about life on other worlds is quickly changing from the realm of speculation to the domain of hard science. Within a few years, as a consequence of the rapid discovery by astronomers of planets around other stars, astronomers very likely will have discovered clear evidence of life beyond the Earth. Such a discovery of extraterrestrial life will change everything.  Knowing the answer as to whether humanity has company in the universe will trigger one of the greatest intellectual revolutions in history, not the least of which will be a challenge for at least some terrestrial religions. Which religions will handle the discovery of extraterrestrial life with ease and which will struggle to assimilate this new knowledge about our place in the universe? Some religions as currently practiced appear to only be viable on Earth. Other religions could be practiced on distant worlds but nevertheless identify both Earth as a place and humankind as a species of singular spiritual re...

Origin of spherule samples recovered from antarctic ice sheet-Terrestrial or extraterrestrial?

Energy Technology Data Exchange (ETDEWEB)

Sekimoto, Shun; Takamiya, Koichi; Shibata, Seiichi [Research Reactor Institute, Kyoto University, Osaka (Japan); Kobayashi, Takayuki [College of Humanities and Sciences, Nihon University, Tokyo (Japan); Ebihara, Mitsuru [Dept. of Chemistry, Tokyo Metropolitan University, Tokyo (Japan)

2016-04-15

Thirty-eight spherules from the Antarctic ice sheet were analyzed using neutron activation analysis under two different conditions to investigate their origin. In almost all of these spherules, the contents of iron, cobalt, and manganese were determined to be 31% to 88%, 17 mg/kg to 810 mg/kg, and 0.017% to 7%, respectively. A detectable iridium content of 0.84 mg/kg was found in only one spherule, which was judged to be extraterrestrial in origin. A comparison of elemental compositions of the Antarctic spherules analyzed in this study with those of deep-sea sediment spherules and those of terrestrial materials revealed that most of the Antarctic spherules except for the sample in which iridium was detected could not be identified as extraterrestrial in origin.

Energy use, entropy and extra-terrestrial civilizations

International Nuclear Information System (INIS)

Hetesi, Zsolt

2010-01-01

The possible number of extra-terrestrial civilizations is estimated by the Drake-equation. Many articles pointed out that there are missing factors and over-estimations in the original equation. In this article we will point out that assuming some axioms there might be several limits for a technical civilization. The key role of the energy use and the problem of the centres and periphery strongly influence the value of the Llifetime of a civilization. Our development have several edifications of the investigations of the growth of an alien civilization.

Energy use, entropy and extra-terrestrial civilizations

Energy Technology Data Exchange (ETDEWEB)

Hetesi, Zsolt, E-mail: zs.hetesi@astro.elte.h [Eoetvoes University, Department of Astronomy, Budapest, H-1518, PO Box 32 (Hungary)

2010-03-01

The possible number of extra-terrestrial civilizations is estimated by the Drake-equation. Many articles pointed out that there are missing factors and over-estimations in the original equation. In this article we will point out that assuming some axioms there might be several limits for a technical civilization. The key role of the energy use and the problem of the centres and periphery strongly influence the value of the Llifetime of a civilization. Our development have several edifications of the investigations of the growth of an alien civilization.

An Earth-Based Equivalent Low Stretch Apparatus to Assess Material Flammability for Microgravity and Extraterrestrial Fire-Safety Applications

Science.gov (United States)

Olson, S. L.; Beeson, H.; Haas, J. P.

2003-01-01

The objective of this project is to modify the standard oxygen consumption (cone) calorimeter (described in ASTM E 1354 and NASA STD 6001 Test 2) to provide a reproducible bench-scale test environment that simulates the buoyant or ventilation flow that would be generated by or around a burning surface in a spacecraft or extraterrestrial gravity level. This apparatus will allow us to conduct normal gravity experiments that accurately and quantitatively evaluate a material's flammability characteristics in the real-use environment of spacecraft or extra-terrestrial gravitational acceleration. The Equivalent Low Stretch Apparatus (ELSA) uses an inverted cone geometry with the sample burning in a ceiling fire configuration that provides a reproducible bench-scale test environment that simulates the buoyant or ventilation flow that would be generated by a flame in a spacecraft or extraterrestrial gravity level. Prototype unit testing results are presented in this paper. Ignition delay times and regression rates for PMMA are presented over a range of radiant heat flux levels and equivalent stretch rates which demonstrate the ability of ELSA to simulate key features of microgravity and extraterrestrial fire behavior.

Is Your Gut Conscious? Is an Extraterrestrial?

Science.gov (United States)

Vos Post, Jonathan

2011-10-01

This paper speculates on questions intending to be taken scientifically rather than metaphysically: "Can the human gut (enteric nervous system) be conscious?"; "Can your immune system think?"; "Could consciousness be coded in DNA?"; "What do we mean when asserting that an Extraterrestrial is Thinking, or is Conscious? We explore through reference to theory, experiment, and computational models by Christof Koch (Caltech), Barbara Wold (Caltech), and Stuart Kauffman (University of Calgary, Tampere University of Technology, Santa Fe Institute). We use a tentative new definition of thinking, designed to be applicable for humans, cetecea, corvids, artificial intelligences, and extraterrestrial intelligences of any substrate (i.e. Life as We Do Not Know It): "Thinking is the occurrence, transformation, and storage in a mind or brain (or simulation thereof) of information-bearing structures (representations) of one kind or another, such as thoughts, concept, percepts, ideas, impressions, notions, rules, schemas, images, phantasms, or subpersonal representations." We use the framework for Consciousness developed by Francis Crick and Christof Koch. We try to describe scientific goals, but discuss Philosophy sufficient to avoid naïve philosophical category errors (thus are careful not to conflate thought, consciousness, and language) Penrose, Hameroff, and Kauffman speculate (differently) that CNS consciousness is a macroscopic quantum phenomenon. Might intestinal, immune system, or genetic regulatory network dynamics exhibit emergent cooperative quantum effects? The speculations are in the context of Evolution by Natural Selection, presumed to operate throughout the Cosmos, and recent work in the foundations of Computational Biology and Quantum Mechanics.

Analytical SuperSTEM for extraterrestrial materials research

Energy Technology Data Exchange (ETDEWEB)

Bradley, J P; Dai, Z R

2009-09-08

Electron-beam studies of extraterrestrial materials with significantly improved spatial resolution, energy resolution and sensitivity are enabled using a 300 keV SuperSTEM scanning transmission electron microscope with a monochromator and two spherical aberration correctors. The improved technical capabilities enable analyses previously not possible. Mineral structures can be directly imaged and analyzed with single-atomic-column resolution, liquids and implanted gases can be detected, and UV-VIS optical properties can be measured. Detection limits for minor/trace elements in thin (<100 nm thick) specimens are improved such that quantitative measurements of some extend to the sub-500 ppm level. Electron energy-loss spectroscopy (EELS) can be carried out with 0.10-0.20 eV energy resolution and atomic-scale spatial resolution such that variations in oxidation state from one atomic column to another can be detected. Petrographic mapping is extended down to the atomic scale using energy-dispersive x-ray spectroscopy (EDS) and energy-filtered transmission electron microscopy (EFTEM) imaging. Technical capabilities and examples of the applications of SuperSTEM to extraterrestrial materials are presented, including the UV spectral properties and organic carbon K-edge fine structure of carbonaceous matter in interplanetary dust particles (IDPs), x-ray elemental maps showing the nanometer-scale distribution of carbon within GEMS (glass with embedded metal and sulfides), the first detection and quantification of trace Ti in GEMS using EDS, and detection of molecular H{sub 2}O in vesicles and implanted H{sub 2} and He in irradiated mineral and glass grains.

Miniature Time of Flight Mass Spectrometer for Space and Extraterrestrial Applications, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The PI has developed a miniature time-of-flight mass spectrometer (TOF-MS), which can be op-timized for space and extraterrestrial applications, by using a...

FINDING EXTRATERRESTRIAL LIFE USING GROUND-BASED HIGH-DISPERSION SPECTROSCOPY

International Nuclear Information System (INIS)

Snellen, I. A. G.; Le Poole, R.; Brogi, M.; Birkby, J.; De Kok, R. J.

2013-01-01

Exoplanet observations promise one day to unveil the presence of extraterrestrial life. Atmospheric compounds in strong chemical disequilibrium would point to large-scale biological activity just as oxygen and methane do in the Earth's atmosphere. The cancellation of both the Terrestrial Planet Finder and Darwin missions means that it is unlikely that a dedicated space telescope to search for biomarker gases in exoplanet atmospheres will be launched within the next 25 years. Here we show that ground-based telescopes provide a strong alternative for finding biomarkers in exoplanet atmospheres through transit observations. Recent results on hot Jupiters show the enormous potential of high-dispersion spectroscopy to separate the extraterrestrial and telluric signals, making use of the Doppler shift of the planet. The transmission signal of oxygen from an Earth-twin orbiting a small red dwarf star is only a factor of three smaller than that of carbon monoxide recently detected in the hot Jupiter τ Boötis b, albeit such a star will be orders of magnitude fainter. We show that if Earth-like planets are common, the planned extremely large telescopes can detect oxygen within a few dozen transits. Ultimately, large arrays of dedicated flux-collector telescopes equipped with high-dispersion spectrographs can provide the large collecting area needed to perform a statistical study of life-bearing planets in the solar neighborhood.

Quaternary chronostratigraphy and stable isotope paleoecology of Big Bone Lick, Kentucky, USA

Science.gov (United States)

Tankersley, Kenneth Barnett; Murari, Madhav Krishna; Crowley, Brooke E.; Owen, Lewis A.; Storrs, Glenn W.; Mortensen, Litsa

2015-05-01

Big Bone Lick (BBL) in northern Kentucky, USA has been a critical geologic site in the historical development of North American Quaternary vertebrate paleontology since the 1700s. Sedimentology, geoarcheology, paleontology, accelerator mass spectrometry radiocarbon and optically stimulated luminescence dating, and stable carbon and nitrogen isotope analyses were undertaken to develop a chronostratigraphy and history of erosion and deposition for the site to provide a foundation for understanding taphonomy, and species extinction and adaptation to periods of climatic and environmental change. Three geomorphic surfaces are recognized at BBL representing significant periods of floodplain aggradation since the last glacial maximum (26.5-19 ka) dating to the Oldest Dryas (Tazewell, 25-19 ka), the Older Dryas (Cary, 14-12 ka), and late Holocene (5 ka to the present). Unconformities suggest significant periods of degradation during the transitions from cold and dry to warm and moist climates from the Oldest Dryas (Tazewell) to Bølling Oscillation, from the Older Dryas (Cary) to the Allerød, and from the Younger Dryas (Valders) to the Holocene Climatic Optimum. Increased anthropogenic activities since 5 ka may have increased soil upland erosion and floodplain aggradation. Stable isotopes demonstrate that the landscape has been dominated by C3 vegetation since the last glacial maximum.

Mainstream Media and Social Media Reactions to the Discovery of Extraterrestrial Life

Science.gov (United States)

Jones, Morris

The rise of online social media (such as Facebook and Twitter) has overturned traditional top-down and stovepiped channels for mass communications. As social media have risen, traditional media sources have been steadily crippled by economic problems, resulting in a loss of capabilities and credibility. Information can propagate rapidly without the inclusion of traditional editorial checks and controls. Mass communications strategies for any type of major announcement must account for this new media landscape. Scientists announcing the discovery of extraterrestrial life will trigger a multifaceted and unpredictable percolation of the story through the public sphere. They will also potentially struggle with misinformation, rumours and hoaxes. The interplay of official announcements with the discussions of an extraterrestrial discovery on social media has parallels with traditional theories of mass communications. A wide spectrum of different messages is likely to be received by different segments of the community, based on their usage patterns of various media and online communications. The presentation and interpretation of a discovery will be hotly debated and contested within online media environments. In extreme cases, this could lead to "editorial wars" on collaborative media projects as well as cyber-attacks on certain online services and individuals. It is unlikely that a clear and coherent message can be propagated to a near-universal level. This has the potential to contribute to inappropriate reactions in some sectors of the community. Preventing unnecessary panic will be a priority. In turn, the monitoring of online and social media will provide a useful tool for assessing public reactions to a discovery of extraterrestrial life. This will help to calibrate public communications strategies following in the wake of an initial announcement.

Detection of Lateglacial distal tephra layers in the Netherlands

NARCIS (Netherlands)

Davies, S.M.; Hoek, W.Z.; Bohncke, S.J.P.; Lowe, J.; Pyne O'Donnle, S.; Turney, C.S.M.

2005-01-01

Three distal tephra layers or cryptotephras have been detected within a sedimentary sequence from the Netherlands that spans the last glacial-interglacial transition. Geochemical analyses identify one as the Vedde Ash, which represents the southernmost discovery of this mid-Younger Dryas tephra so

(CH4)-C-14 Measurements in Greenland Ice: Investigating Last Glacial Termination CH4 Sources

DEFF Research Database (Denmark)

Petrenko, V. V.; Smith, A. M.; Brook, E. J.

2009-01-01

by direct cosmogenic C-14 production in ice. C-14 of CO was measured to better understand this process and correct the sample (CH4)-C-14. Corrected results suggest that wetland sources were likely responsible for the majority of the Younger Dryas-Preboreal CH4 rise.......The cause of a large increase of atmospheric methane concentration during the Younger Dryas-Preboreal abrupt climatic transition (similar to 11,600 years ago) has been the subject of much debate. The carbon-14 (C-14) content of methane ((CH4)-C-14) should distinguish between wetland and clathrate...... contributions to this increase. We present measurements of (CH4)-C-14 in glacial ice, targeting this transition, performed by using ice samples obtained from an ablation site in west Greenland. Measured (CH4)-C-14 values were higher than predicted under any scenario. Sample (CH4)-C-14 appears to be elevated...

Siderophilic Cyanobacteria for the Development of Extraterrestrial Photoautotrophic Biotechnologies

Science.gov (United States)

Brown, I. I.; McKay, D. S.

2010-01-01

In-situ production of consumables (mainly oxygen) using local resources (In-Situ Resource Utilization-ISRU) will significantly facilitate current plans for human exploration and settlement of the solar system, starting with the Moon. With few exceptions, nearly all technologies developed to date have employed an approach based on inorganic chemistry. None of these technologies include concepts for integrating the ISRU system with a bioregenerative life support system and a food production system. Therefore, a new concept based on the cultivation of cyanobacteria (CB) in semi-closed biogeoreactor, linking ISRU, a biological life support system, and food production, has been proposed. The key feature of the biogeoreactor is to use lithotrophic CB to extract many needed elements such as Fe directly from the dissolved regolith and direct them to any technological loop at an extraterrestrial outpost. Our studies showed that siderophilic (Fe-loving) CB are capable to corrode lunar regolith stimulants because they secrete chelating agents and can tolerate [Fe] up to 1 mM. However, lunar and Martian environments are very hostile (very high UV and gamma-radiation, extreme temperatures, deficit of water). Thus, the selection of CB species with high potential for extraterrestrial biotechnologies that may be utilized in 15 years must be sponsored by NASA as soon as possible. The study of the genomes of candidate CB species and the metagenomes of the terrestrial environments which they inhabit is critical to make this decision. Here we provide preliminary results about peculiarities of the genomes of siderophilic CB revealed by analyzing the genome of siderophilic cyanobacterium JSC-1 and the metagenome of iron depositing hot spring (IDHS) Chocolate Pots (Yellowstone National Park, Wyoming, USA). It has been found that IDHS are richer with ferrous iron than the majority of hot springs around the world. Fe2+ is known to increase the magnitude of oxidative stress in prokaryotes

The Search for Extraterrestrial Intelligence in the 1960s: Science in Popular Culture

Science.gov (United States)

Smith, Sierra

2012-01-01

Building upon the advancement of technology during the Second World War and the important scientific discoveries which have been made about the structure and components of the universe, scientists, especially in radio astronomy and physics, began seriously addressing the possibility of extraterrestrial intelligence in the 1960s. The Search for Extraterrestrial Intelligence (SETI) quickly became one of the most controversial scientific issues in the post Second World War period. The controversy played out, not only in scientific and technical journals, but in newspapers and in popular literature. Proponents for SETI, including Frank Drake, Carl Sagan, and Philip Morrison, actively used a strategy of engagement with the public by using popular media to lobby for exposure and funding. This paper will examine the use of popular media by scientists interested in SETI to popularize and heighten public awareness and also to examine the effects of popularization on SETI's early development. My research has been generously supported by the National Radio Astronomy Observatory.

Which colors would extraterrestrial civilizations use to transmit signals?: The ;magic wavelengths; for optical SETI

Science.gov (United States)

Narusawa, Shin-ya; Aota, Tatusya; Kishimoto, Ryo

2018-04-01

In the case of radio SETI, there are predicted frequencies which extraterrestrial beings select to send messages to other civilizations. Those are called ;magic frequencies. Considering the optical region, terrestrial technologies can not transmit arbitrary wavelengths of high-power optical lasers, easily. In this article, we discuss communications among civilizations with the same level of technology as us to enhance the persuasive power. It might be possible to make a reasonable assumption about the laser wavelengths transmitted by extraterrestrial intelligences to benefit optical SETI (OSETI) methods. Therefore, we propose some ;magic wavelengths; for spectroscopic OSETI observations in this article. From the senders point of view, we argue that the most favorable wavelength used for interstellar communication would be the one of YAG lasers, at 1.064 μm or its Second Harmonic Generation (532.1 nm). On the contrary, there are basic absorption lines in the optical spectra, which are frequently observed by astrophysicists on Earth. It is possible that the extraterrestrials used lasers, which wavelengths are tuned to such absorption lines for sending messages. In that case, there is a possibility that SHG and/or Sum Frequency Generation of YAG and YLF lasers are used. We propose three lines at, 393.8 nm (near the Ca K line), 656.5 nm (near the Hα line) and 589.1 nm (Na D2 line) as the magic wavelengths.

Irrational ideas. Older vs. younger inpatients.

Science.gov (United States)

Hyer, L A; Jacobsen, R; Harrison, W R

1985-04-01

The relationship to age of irrational beliefs among psychiatric inpatients has not been explored using the rational-emotive model. This study addressed the following two questions: 1) Do older and younger psychiatric inpatients differ in irrational beliefs? 2) Do older depressives differ from older nondepressives in irrational beliefs? Upon admission to a large medical center, 58 younger (less than 45 years old) and 54 older (greater than 55 years old) subjects were assessed on a battery of psychological tests, including the Idea Inventory and the Beck Depression Inventory. Results showed that older and younger inpatients did not differ on irrational beliefs. Results also showed that older and younger groups of depressives did not differ on the irrationality scores. When a correlational analysis was used, depression was related to irrationality within the older group but not within the younger group.

The Holocene History of Placentia Bay, Newfoundland

DEFF Research Database (Denmark)

Sheldon, Christina; Seidenkrantz, Marit-Solveig; Reynisson, Njall

2013-01-01

Marine sediments analyzed from cores taken in Placentia Bay, Newfoundland, located in the Labrador Sea, captured oceanographic and climatic changes from the end of the Younger Dryas through the Holocene. Placentia Bay is an ideal site to capture changes in both the south-flowing Labrador Current ...

Extraterrestrial materials examined by mean of nuclear microprobe

Science.gov (United States)

Khodja, H.; Smith, T.; Engrand, C.; Herzog, G.; Raepsaet, C.

2013-07-01

Comet fragments, micrometeorites, and Interplanetary Dust Particles (IDPs) are small objects (purpose, we need instruments and methods that provide both microanalysis and detailed imaging. In these respects, the nuclear microprobe offers many potential advantages: (i) the spatial resolution, ∼1 μm is well-matched to the typical object dimensions, (ii) with some reservations, it is non-destructive when carefully conducted, (iii) it is quantitative, and especially sensitive for light elements. At the Saclay nuclear microprobe, we have been performing analyses of extraterrestrial objects for many years. We review some of these studies, emphasizing the specific requirements for successful analyses. We also discuss the potential pitfalls that may be encountered.

The role of the Asian winter monsoon in the rapid propagation of abrupt climate changes during the last deglaciation

Science.gov (United States)

Chu, Guoqiang; Sun, Qing; Zhu, Qingzeng; Shan, Yabing; Shang, Wenyu; Ling, Yuan; Su, Youliang; Xie, Manman; Wang, Xishen; Liu, Jiaqi

2017-12-01

High-resolution temperature records spanning the last deglaciation from low latitudes are scarce; however, they are important for understanding the rapid propagation of abrupt climate events throughout the Northern Hemisphere and the tropics. Here, we present a branched GDGTs-based temperature reconstruction from the sediments of Maar Lake Huguangyan in tropical China. The record reveals that the mean temperature during the Oldest Dryas was 17.8 °C, which was followed by a two-step increase of 2-3 °C to the Bølling-Allerød, a decrease to 19.8 °C during the Younger Dryas, and a rapid warming at the onset of the Holocene. The Oldest Dryas was about 2 °C warmer than the Younger Dryas. The reconstructed temperature was weighted towards the wintertime since the lake is monomictic and the mixing process in winter supplies nutrients from the lake bottom to the entire water column, greatly promoting biological productivity. In addition, the winter-biased temperature changes observed in the study are more distinctive than the summer-biased temperature records from extra-tropical regions of East Asia. This implies that the temperature decreases during abrupt climatic events were mainly a winter phenomenon. Within the limits of the dating uncertainties, the broadly similar pattern of winter-weighted temperature change observed in both tropical Lake Huguangyan and in Greenland ice cores indicates the occurrence of tightly-coupled interactions between high latitude ice sheets and land areas in the tropics. We suggest that the winter monsoon (especially cold surges) could play an important role in the rapid transmission of the temperature signal from the Arctic to the tropics.

Older and Younger Adults’ Accuracy in Discerning Health and Competence in Older and Younger Faces

Science.gov (United States)

Zebrowitz, Leslie A.; Franklin, Robert G.; Boshyan, Jasmine; Luevano, Victor; Agrigoroaei, Stefan; Milosavljevic, Bosiljka; Lachman, Margie E.

2015-01-01

We examined older and younger adults’ accuracy judging the health and competence of faces. Accuracy differed significantly from chance and varied with face age but not rater age. Health ratings were more accurate for older than younger faces, with the reverse for competence ratings. Accuracy was greater for low attractive younger faces, but not for low attractive older faces. Greater accuracy judging older faces’ health was paralleled by greater validity of attractiveness and looking older as predictors of their health. Greater accuracy judging younger faces’ competence was paralleled by greater validity of attractiveness and a positive expression as predictors of their competence. Although the ability to recognize variations in health and cognitive ability is preserved in older adulthood, the effects of face age on accuracy and the different effects of attractiveness across face age may alter social interactions across the life span. PMID:25244467

Last Glacial Maximum and Lateglacial in the Polish High Tatra Mountains - Revised deglaciation chronology based on the 10Be exposure age dating

Science.gov (United States)

Makos, Michał; Rinterknecht, Vincent; Braucher, Régis; Tołoczko-Pasek, Anna; Arnold, Maurice; Aumaître, Georges; Bourlès, Didier; Keddadouche, Karim; Aster Team

2018-05-01

Deglaciation chronology of the Polish High Tatra Mountains has been reconstructed based on 10Be exposure age dating. Fifty-seven rock samples were collected from boulders located on the terminal and lateral moraines that limit the horizontal extent of the LGM and the Lateglacial glaciers in the Biała Woda and Sucha Woda catchments. The uncertainty-weighted mean age of 21.5 ± 2.5 ka obtained for the maximum terminal moraine in the Sucha Woda Valley indicates that the oldest preserved moraines were formed during the global LGM. The age population ranges between 15.1 ± 1.0 and 28.3 ± 2.0 ka, and suggests that glaciers reached their maximum position (LGM I) as early as 28-25 ka and the final stabilization of the form occurred much later possibly after melting of buried dead ice. The younger glacial oscillation (LGM II) occurred no later than 20.5 ka and is represented by well-preserved termino-lateral moraine systems in the Pańszczyca Valley. The first Lateglacial stage (LG1) in the study area is documented in the Rybi Potok Valley at the RP1 moraine (1300 m a.s.l.), which was stable at around 16.6 ± 0.3 ka. The younger LG2 stage has no defined absolute age, however, it is constrained between 16.5 and 15.5 ka by the timing of the LG3 stage. This cold event is represented by well-formed moraines in the Roztoka/Pięć Stawów Polskich, Rybi Potok and Pańszczyca valleys of which exposure age indicates their deposition between 15.0 ± 0.5 and 15.6 ± 0.1 ka. The LG1, LG2 and LG3 stages likely occurred during the Oldest Dryas cold stage (Greenland Stadial 2.1a) related to the North Atlantic cooling Heinrich Event 1. The youngest glacial oscillation is evidenced by moraines in the Pusta and Pańszczyca valleys. These moraines are composed of very large granitic blocks of which exposure ages often exhibit isotope inheritance. This is reflected by the youngest P3 moraine in the Pańszczyca Valley with a mean age of deposition close to the LGM. The R4 moraine system in

Millennial-scale variations in dustiness recorded in Mid-Atlantic sediments from 0 to 70 ka

Science.gov (United States)

Middleton, Jennifer L.; Mukhopadhyay, Sujoy; Langmuir, Charles H.; McManus, Jerry F.; Huybers, Peter J.

2018-01-01

Sedimentary records of dust deposition in the subtropical Atlantic provide important constraints on millennial- and orbital-scale variability in atmospheric circulation and North African aridity. Constant flux proxies, such as extraterrestrial helium-3, yield dust flux records that are independent of the biases caused by lateral sediment transport and limited resolution that may be associated with age-model-derived mass accumulation rates. However, Atlantic dust records constrained using constant flux proxies are sparsely distributed and generally limited to the past 20 ka. Here we extend the Atlantic record of North African dust deposition to 70 ka using extraterrestrial helium-3 and measurements of titanium, thorium, and terrigenous helium-4 in two sediment cores collected at 26°N and 29°N on the Mid-Atlantic Ridge and compare results to model estimates for dust deposition in the subtropical North Atlantic. Dust proxy fluxes between 26°N and 29°N are well correlated, despite variability in lateral sediment transport, and underscore the utility of extraterrestrial helium-3 for constraining millennial-scale variability in dust deposition. Similarities between Mid-Atlantic dust flux trends and those observed along the Northwest African margin corroborate previous interpretations of dust flux variability over the past 20 ka and suggest that long distance transport and depositional processes do not overly obscure the signal of North African dust emissions. The 70 ka Mid-Atlantic record reveals a slight increase in North African dustiness from Marine Isotope Stage 4 through the Last Glacial Maximum and a dramatic decrease in dustiness associated with the African Humid Period. On the millennial-scale, the new records exhibit brief dust maxima coincident with North Atlantic cold periods such as the Younger Dryas, and multiple Heinrich Stadials. The correlation between Mid-Atlantic dust fluxes and previous constraints on North African aridity is high. However

Climate bifurcation during the last deglaciation?

NARCIS (Netherlands)

Lenton, T.M.; Livina, V.N.; Dakos, V.; Scheffer, M.

2012-01-01

There were two abrupt warming events during the last deglaciation, at the start of the Bolling-Allerod and at the end of the Younger Dryas, but their underlying dynamics are unclear. Some abrupt climate changes may involve gradual forcing past a bifurcation point, in which a prevailing climate state

Limits on diffuse fluxes of high energy extraterrestrial neutrinos with the AMANDA-B10 detector

International Nuclear Information System (INIS)

Ahrens, J.; Bai, X.; Barwick, S.W.; Bay, R.C.; Becka, T.; Becker, K.-H.; Bernardini, E.; Bertrand, D.; Binon, F.; Boeser, S.; Botner, O.; Bouchta, A.; Bouhali, O.; Burgess, T.; Carius, S.; Castermans, T.; Chirkin, D.; Conrad, J.; Cooley, J.; Cowen, D.F.; Davour, A.; De Clercq, C.; DeYoung, T.; Desiati, P.; Doksus, P.; Ekstrom, P.; Feser, T.; Gaisser, T.K.; Ganugapati, R.; Gaug, M.; Geenen, H.; Gerhardt, L.; Goldschmidt, A.; Hallgren, A.; Halzen, F.; Hanson, K.; Hardtke, R.; Hauschildt, T.; Hellwig, M.; Herquet, P.; Hill, G.C.; Hulth, P.O.; Hughey, B.; Hultqvist, K.; Hundertmark, S.; Jacobsen, J.; Karle, A.; Kuehn, K.; Kim, J.; Kopke, L.; Kowalski, M.; Lamoureux, J.I.; Leich, H.; Leuthold, M.; Lindahl, P.; Liubarsky, I.; Madsen, J.; Mandli, K.; Marciniewski, P.; Matis, H.S.; McParland, C.P.; Messarius, T.; Miller, T.C.; Minaeva, Y.; Miocinovic, P.; Mock, P.C.; Morse, R.; Neunhoffer, T.; Niessen, P.; Nygren, D.R.; Ogelman, H.; Olbrechts, P.; Perez de los Heros, C.; Pohl, A.C.; Porrata, R.; Price, P.B.; Przybylski, G.T.; Rawlins, K.; Resconi, E.; Rhode, W.; Ribordy, M.; Richter, S.; Rodriguez Martino, J.; Romenesko, P.; Ross, D.; Sander, H.-G.; Schlenstedt, S.; Schinarakis, K.; Schmidt, T.; Schneider, D.; Schwarz, R.; Silvestri, A.; Solarz, M.; Stamatikos, M.; Spiczak, G.M.; Spiering, C.; Steele, D.; Steffen, P.; Stokstad, R.G.; Sulanke, K.-H.; Taboada, I.; Tilav, S.; Wagner, W.; Walck, C.; Wang, Y.-R.; Wiebusch, C.H.; Wiedemann, C.; Wischnewski, R.; Wissing, H.; Woschnagg, K.; Wu, W.; Yodh, G.; Young, S.

2003-01-01

Data from the AMANDA-B10 detector taken during the austral winter of 1997 have been searched for a diffuse flux of high energy extraterrestrial muon-neutrinos, as predicted from, e.g., the sum of all active galaxies in the universe. This search yielded no excess events above those expected from the background atmospheric neutrinos, leading to upper limits on the extraterrestrial neutrino flux. For an assumed E -2 spectrum, a 90 percent classical confidence level upper limit has been placed at a level E 2 Phi(E) = 8.4 x 10 -7 GeV cm -2 s -1 1 sr -1 (for a predominant neutrino energy range 6-1000 TeV) which is the most restrictive bound placed by any neutrino detector. When specific predicted spectral forms are considered, it is found that some are excluded

Habitability and the Possibility of Extraterrestrial Life in the Early Telescope Era

Science.gov (United States)

Reynolds, Sarah

2014-01-01

Early telescopic observations of the Moon and planets prompted great interest in the already-existing debate about the possibility of life on the Moon and other worlds. New observations of the lunar surface, revealing an apparently Earth-like terrain and possibly the presence of bodies of water, were often considered in relation to their implications for the existence of lunar inhabitants. This depended upon establishing what constituted the fundamental requirements for life and the boundaries of habitability. The growing support for the heliocentric Copernican astronomy was also changing perceptions of the relationships between the Earth, the Moon, and the planets. Works such as Johannes Kepler’s Somnium and John Wilkins’ The Discovery of a World in the Moone presented views of extraterrestrial life that were shifting from the supernatural to the natural, in correspondence with the celestial bodies’ new positions in the cosmos. This paper considers how these and other works from the early telescope era reveal changes in the nature of astronomical speculation about extraterrestrial life and the conditions construed as “habitability,” and what significance that history has for us today in the new era of extrasolar planet discovery.

Terrestrial and extraterrestrial superresonators as drivers for an inertial confinement fusion reactor

International Nuclear Information System (INIS)

Seifritz, W.; Vath, W.

1992-01-01

This paper reports on the recirculating power fraction of a laser-driven inertial confinement fusion (ICF) reactor which can be reduced by using laser diodes to pump a neodymium solid-state laser. To overcome the high costs of two-dimensional arrays of laser diodes, two types of superresonators are proposed: a terrestrially based one and an extraterrestrially based one on a geostationary orbit. Both are designed in such a way that a sequence of short laser pulses (10 to 20 ns wide), each with an energy of 5 to 10 MJ and a frequency of 10 Hz, are produced to trigger a deuterium-tritium ICF reactor. The terrestrial superresonator needs a much smaller number of two-dimensional laser diode arrays than a conventionally pumped once-through solid-state laser system, and the extraterrestrial resonator is pumped by means of concentrated solar radiation. In practice, at least an order of magnitude fewer laser diodes and crystalline calcium fluoride gain media are needed to meet the requirements of a laser driver for an ICF reactor. If, finally, a liquid neodymium laser system could be used for an ICF reactor, the cooling of the gain slabs would be facilitated substantially

Planetary Protection Knowledge Gaps for Human Extraterrestrial Missions: Workshop Report

Science.gov (United States)

Race, Margaret S. (Editor); Johnson, James E. (Editor); Spry, James A. (Editor); Siegel, Bette; Conley, Catharine A.

2015-01-01

This report on Planetary Protection Knowledge Gaps for Human Extraterrestrial Missions summarizes the presentations, deliberations and findings of a workshop at NASA Ames Research Center, March 24-26, 2015, which was attended by more than 100 participants representing a diverse mix of science, engineering, technology, and policy areas. The main objective of the three-day workshop was to identify specific knowledge gaps that need to be addressed to make incremental progress towards the development of NASA Procedural Requirements (NPRs) for Planetary Protection during human missions to Mars.

The G-HAT Search for Advanced Extraterrestrial Civilizations: The Reddest Extended WISE Sources

Science.gov (United States)

Maldonado, Jessica; Povich, Matthew S.; Wright, Jason; Griffith, Roger; Sigurdsson, Steinn; Mullan, Brendan L.

2015-01-01

Freeman Dyson (1960) theorized how to identify possible signatures of advanced extra-terrestrial civilizations by their waste heat, an inevitable byproduct of a civilization using a significant fraction of the luminosity from their host star. If a civilizations could tap the starlight throughout their host galaxy their waste heat would be easily detectable by recent infrared surveys. The Glimpsing Heat from Alien Technologies (G-HAT) pilot project aims to place limits on the existence of extraterrestrial civilizations at pan-galactic scales. We present results from the G-HAT cleaned catalog of 563 extremely red, extended high Galactic latitude (|b| ≥ 10) sources from the WISE All-Sky Catalog. Our catalog includes sources new to the scientific literature along with well-studied objects (e.g. starburst galaxies, AGN, and planetary nebulae) that exemplify extreme WISE colors. Objects of particular interest include a supergiant Be star (48 Librae) surrounded by a resolved, mid-infrared nebula, possibly indicating dust in the stellar wind ejecta, and a curious cluster of seven extremely red WISE sources (associated with IRAS 04287+6444) that have no optical counterparts.

Inscribed matter as an energy-efficient means of communication with an extraterrestrial civilization.

Science.gov (United States)

Rose, Christopher; Wright, Gregory

2004-09-02

It is well known that electromagnetic radiation-radio waves-can in principle be used to communicate over interstellar distances. By contrast, sending physical artefacts has seemed extravagantly wasteful of energy, and imagining human travel between the stars even more so. The key consideration in earlier work, however, was the perceived need for haste. If extraterrestrial civilizations existed within a few tens of light years, radio could be used for two-way communication on timescales comparable to human lifetimes (or at least the longevities of human institutions). Here we show that if haste is unimportant, sending messages inscribed on some material can be strikingly more energy efficient than communicating by electromagnetic waves. Because messages require protection from cosmic radiation and small messages could be difficult to find among the material clutter near a recipient, 'inscribed matter' is most effective for long archival messages (as opposed to potentially short "we exist" announcements). The results suggest that our initial contact with extraterrestrial civilizations may be more likely to occur through physical artefacts-essentially messages in a bottle-than via electromagnetic communication.

Search for extraterrestrial life: recent developments. Proceedings

Energy Technology Data Exchange (ETDEWEB)

Papagiannis, M D [ed.

1985-01-01

Seventy experts from 20 different countries discuss the many interrelated aspects of the search for extraterrestrial life, including the search for other planetary systems where life may originate and evolve, the widespread presence of complex prebiotic molecules in our Solar System and in interstellar space which could be precursors of life, and the universal aspects of the biological evolution on Earth. They also discuss the nearly 50 radio searches that were undertaken in the last 25 years, the technological progress that has occurred in this period, and the plans for the future including the comprehensive SETI search program that NASA is now preparing for the 1990's. Extensive introductions by the Editor to each of the 8 sections, make this volume friendly even to the non-specialist who has a genuine interest for this new field. 549 refs.; 84 figs.; 21 tabs.

SPE (tm) regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications

Science.gov (United States)

Mcelroy, J. F.

1990-01-01

Viewgraphs on SPE regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications are presented. Topics covered include: hydrogen-oxygen regenerative fuel cell energy storage system; electrochemical cell reactions; SPE cell voltage stability; passive water removal SPE fuel cell; fuel cell performance; SPE water electrolyzers; hydrophobic oxygen phase separator; hydrophilic/electrochemical hydrogen phase separator; and unitized regenerative fuel cell.

Vegetation development in south-east Denmark during the Weichselian Late Glacial: palaeoenvironmental studies close to the Palaeolithic site of Hasselø

DEFF Research Database (Denmark)

Mortensen, Morten Fischer; Henriksen, Peter Steen; Christensen, Charlie

2015-01-01

Cultures. The lake sediments encompass the Bølling, Allerød, Younger Dryas and the early Preboreal biostratigraphic periods. An increase in charcoal dust between c. 14,000 and 13,900 cal. BP may be related to the occupation site. This study shows that an ecotone was positioned between present-day Denmark...

Are we alone: The possibility of extraterrestrial civilizations

Science.gov (United States)

Rood, R. T.; Trefil, J. S.

The book explores the possibility of extraterrestrial (ET) intelligence. The formation of stars and planetary systems, the evolution of planetary atmospheres and the evolution of life are reviewed. The possibilities of interstellar communication, ET colonization of other star systems, in addition to earth's colonization of near-earth space are discussed. The state of the earth's depleting energy sources and current technology are used to show why some scientists believe that earth will be colonizing in space within the next century. Current methods of searching for ET intelligence are reviewed, and preliminary designs for various space habitats, including the torus, and discussed, taking into consideration problems that would be encountered. The importance of space colonies for the existence and expansion of the human race is emphasized.

Isotopic evidence for extraterrestrial non- racemic amino acids in the Murchison meteorite

Science.gov (United States)

Engel, M. H.; Macko, S. A.

1997-09-01

Many amino acids contain an asymmetric centre, occurring as laevorotatory, L, or dextrorotatory, D, compounds. It is generally assumed that abiotic synthesis of amino acids on the early Earth resulted in racemic mixtures (L- and D-enantiomers in equal abundance). But the origin of life required, owing to conformational constraints, the almost exclusive selection of either L- or D-enantiomers, and the question of why living systems on the Earth consist of L-enantiomers rather than D-enantiomers is unresolved. A substantial fraction of the organic compounds on the early Earth may have been derived from comet and meteorite impacts. It has been reported previously that amino acids in the Murchison meteorite exhibit an excess of L-enantiomers, raising the possibility that a similar excess was present in the initial inventory of organic compounds on the Earth. The stable carbon isotope compositions of individual amino acids in Murchison support an extraterrestrial origin-rather than a terrestrial overprint of biological amino acids-although reservations have persisted (see, for example, ref. 9). Here we show that individual amino-acid enantiomers from Murchison are enriched in 15N relative to their terrestrial counterparts, so confirming an extraterrestrial source for an L-enantiomer excess in the Solar System that may predate the origin of life on the Earth.

The Schmidt hammer as a relative-age dating tool and its potential for calibrated-age dating in Holocene glaciated environments

Science.gov (United States)

Shakesby, Richard A.; Matthews, John A.; Owen, Geraint

2006-11-01

The Schmidt hammer is a relatively cheap, portable, sturdy instrument with proven value over the last two decades or so in rapidly dating coarse inorganic deposits of diverse origins. Early views were that its dating role was limited to distinguishing recently exposed from much older. Typically, either a few sites of possibly different ages or occasional older surfaces amongst many young sites were studied. More recently, calibration curves based on individual R-value means from small numbers (2-4) of sites of known ages have been used to estimate the ages of undated sites. We present Schmidt hammer rebound ( R-) values from 28 'Little Ice Age' (and younger), 23 Preboreal and 7 Younger Dryas glaciated surfaces in southern Norway in order, first, to test rigorously the robustness of the instrument as a relative-age dating tool. Despite being obtained from different surfaces (moraines, glaciofluvial deposits and bedrock) and varied metamorphic lithologies, the R-value overall means and 95% confidence intervals for the 'Little Ice Age', Preboreal and Younger Dryas age categories (respectively, 60.0±1.6, 41.6±1.4 and 34.2±2.0) are statistically significantly different. Only two outlying sites in the two younger age categories have overlapping confidence intervals, demonstrating remarkable robustness in differentiating early- and late-Holocene surfaces. The distinction between Preboreal and Younger Dryas sites (with terminal dates factors, including some previously considered critical (instrument wear, operator bias, initial rock surface texture), which emerge either as less important than previously argued or as relatively unimportant, together with others previously unreported (e.g. long-term changes in lichen, soil, snow and vegetation covers). Third, we investigate the potential for calibrated-age dating by applying exploratory, linear rates of R-value decline to selected combinations of sites. The results suggest that error limits of ca ±700 to ±1600 years

Climate-induced changes in the trophic status of a Central European lake

Directory of Open Access Journals (Sweden)

Thomas HÜBENER

2009-02-01

Full Text Available We present a case study of the development of Sacrower See, a stratified, eutrophic lake in northeastern Germany, over the past 13,000 years. Total epilimnetic phosphorus (TP concentrations were reconstructed quantitatively using a diatom-TP transfer function. Fossil chironomid assemblages were used to support the trophic reconstruction and helped assessing past hypolimnetic oxygen availability. The results indicate eutrophic and anoxic conditions during the Younger Dryas cold period (~12,700-11,600 cal. BP preceding the present interglacial. Throughout the early and mid-Holocene (~11,600-4000 cal. BP stable oligo- to mesotrophic conditions with diatom-inferred TP values of ~20 μg L-1 prevailed. First evidence of increasing Holocene TP is recorded at ~3500 cal. BP associated with Bronze Age human impact and for the past 900 years diatoms indicate increasing TP values of 30-60 μg L-1. During the early Holocene and the past two millennia chironomids indicated anoxic hypolimnetic conditions. The chironomid fauna is considered typical of oligo- to mesotrophic lakes. As a consequence of strongly increased primary production the hypolimnion of Sacrower See became anoxic again during the past 140 years. Our results indicate that highly productive eutrophic conditions can exist prior to cultural eutrophication. At Sacrower See the shift from eutrophic conditions in the Lateglacial to oligo-mesotrophic conditions in the early and mid-Holocene was associated with the climatic warming at the Younger Dryas/Holocene transition. The high productive state during the cold Younger Dryas is associated with changes in seasonality: the prolonged winters caused longer ice cover, stronger stratification, anoxia in the hypolimnion, and consequent internal phosphorus loading. During the warm Holocene, however, hypolimnetic anoxia and internal phosphorus loading decreased significantly, resulting in a substantially lower productivity.

New tree-ring evidence for the Late Glacial period from the northern pre-Alps in eastern Switzerland

Czech Academy of Sciences Publication Activity Database

Reinig, F.; Nievergelt, D.; Esper, J.; Friedrich, M.; Helle, G.; Hellmann, L.; Kromer, B.; Morganti, S.; Pauly, M.; Sookdeo, A.; Tegel, W.; Treydte, K.; Verstege, A.; Wacker, L.; Büntgen, Ulf

2018-01-01

Roč. 186, APR (2018), s. 215-224 ISSN 0277-3791 Keywords : new-zealand kauri * laacher see volcano * ice-core records * radiocarbon calibration * central-europe * cal bp * southern-hemisphere * last deglaciation * hohenheim oak * climate * Central Europe * Dendrochronology * Late Glacial * Paleoclimatology * Radiocarbon * Subfossil wood * Switzerland * Tree rings * Younger Dryas Impact factor: 4.797, year: 2016

Lacustrine evidence of Holocene environmental change from three Faroese lakes:

DEFF Research Database (Denmark)

Olsen, Jesper; Björck, Svante; Leng, Melanie

2010-01-01

,000 cal yr BP when grasses, sedges and finally shrubs began to dominant the islands. Here we present data from three lake sediment cores and show a much more detailed history from geochemical and isotope data. These data show that the Faroe Islands were deglaciated by the end of Younger Dryas (11,700 e 10...

Impact of the Atlantic Warm Pool on precipitation and temperature in Florida during North Atlantic cold spells

Energy Technology Data Exchange (ETDEWEB)

Donders, Timme H. [Utrecht University, Laboratory of Palaeobotany and Palynology, Institute of Environmental Biology, Utrecht (Netherlands); TNO Geological Survey of the Netherlands, Utrecht (Netherlands); Boer, Hugo Jan de; Dekker, Stefan C. [Utrecht University, Department of Environmental Sciences, Faculty of Geosciences, P.O. Box 80115, Utrecht (Netherlands); Finsinger, Walter; Wagner-Cremer, Friederike [Utrecht University, Laboratory of Palaeobotany and Palynology, Institute of Environmental Biology, Utrecht (Netherlands); Grimm, Eric C. [Research and Collections Center, Illinois State Museum, Springfield, IL (United States); Reichart, Gert Jan [Utrecht University, Geochemistry, Department of Earth Sciences, Faculty of Geosciences, P.O. Box 80021, Utrecht (Netherlands)

2011-01-15

Recurrent phases of increased pine at Lake Tulane, Florida have previously been related to strong stadials terminated by so-called Heinrich events. The climatic significance of these pine phases has been interpreted in different ways. Using a pollen-climate inference model, we quantified the climate changes and consistently found that mean summer precipitation (P{sub JJA}) increased (0.5-0.9 mm/day) and mean November temperature increased (2.0-3.0 C) during pine phases coeval with Heinrich events and the Younger Dryas. Marine sea surface temperature records indicate that potential sources for these moisture and heat anomalies are in the Gulf of Mexico and the western tropical Atlantic. We explain this low latitude warming by an increased Loop Current facilitated by persistence of the Atlantic Warm Pool during summer. This hypothesis is supported by a climate model sensitivity analysis. A positive heat anomaly in the Gulf of Mexico and equatorial Atlantic best approximates the pollen-inferred climate reconstructions from Lake Tulane during the (stadials around) Heinrich events and the Younger Dryas. (orig.)

Study of extraterrestrial disposal of radioactive wastes. Part 1: Space transportation and destination considerations for extraterrestrial disposal of radioactive wastes. [feasibility of using space shuttle

Science.gov (United States)

Thompson, R. L.; Ramler, J. R.; Stevenson, S. M.

1974-01-01

A feasibility study of extraterrestrial disposal of radioactive waste is reported. This report covers the initial work done on only one part of the NASA study, that evaluates and compares possible space destinations and space transportation systems. The currently planned space shuttle was found to be more cost effective than current expendable launch vehicles by about a factor of 2. The space shuttle requires a third stage to perform the waste disposal missions. Depending on the particular mission, this third stage could be either a reusable space tug or an expendable stage such as a Centaur.

Life from the stars?. [extraterrestrial sources contributing to chemical evolution on Earth

Science.gov (United States)

Pendleton, Yvonne J.; Cruikshank, Dale P.

1994-01-01

Scientists are now seriously considering the possibility that organic matter from interstellar space could have influenced, or even spurred, the origin of life on Earth. Various aspects of chemical evolution are discussed along with possible extraterrestrial sources responsible for contributing to Earth's life-producing, chemical composition. Specific topics covered include the following: interstellar matter, molecular clouds, asteroid dust, organic molecules in our solar system, interplanetary dust and comets, meteoritic composition, and organic-rich solar-system bodies.

Extraterrestrial Organic Compounds in Meteorites

Science.gov (United States)

Botta, Oliver; Bada, Jeffrey L.; Meyer, Michael (Technical Monitor)

2003-01-01

Many organic compounds or their precursors found in meteorites originated in the interstellar or circumstellar medium and were later incorporated into planetesimals during the formation of the solar system. There they either survived intact or underwent further processing to synthesize secondary products on the meteorite parent body. The most distinct feature of CI and CM carbonaceous chondrites, two types of stony meteorites, is their high carbon content (up to 3% of weight), either in the form of carbonates or of organic compounds. The bulk of the organic carbon consists of an insoluble macromolecular material with a complex structure. Also present is a soluble organic fraction, which has been analyzed by several separation and analytical procedures. Low detection limits can be achieved by derivatization of the organic molecules with reagents that allow for analysis by gas chromatography/mass spectroscopy and high performance liquid chromatography. The CM meteorite Murchison has been found to contain more than 70 extraterrestrial amino acids and several other classes of compounds including carboxylic acids, hydroxy carboxylic acids, sulphonic and phosphonic acids, aliphatic, aromatic and polar hydrocarbons, fullerenes, heterocycles as well as carbonyl compounds, alcohols, amines and amides. The organic matter was found to be enriched in deuterium, and distinct organic compounds show isotopic enrichments of carbon and nitrogen relative to terrestrial matter.

The Search for Extraterrestrials Intercepting Alien Signals

CERN Document Server

Ross, Monte

2009-01-01

In The Search for Extraterrestrials, Monte Ross explores in detail the key problems in starting a search, the programs that have failed and those that continue. He includes the fundamental considerations and the physics of the necessary laser, UV, IR and RF technologies, as well as coding and information theory considerations. The author explores future possibilities providing the reader with a comprehensive view of the many ways signals from aliens could be sent and explains why the search using RF leaves more than 99% of the electromagnetic spectrum unexamined. He also demonstrates the many parts of the electromagnetic spectrum, considering the next likely steps in this unique enterprise. Given man’s intrinsic nature to explore, the search will continue in one form or many, until success is achieved, which may be tomorrow or a millennium away. In summary, Monte Ross proposes to get around the failure of a fruitless search at radio frequencies by developing, in a precise way, the argument for searching for...

Extraterrestrial Life: Life on Mars - Then and Now

Science.gov (United States)

Arrhenius, Gustaf; Mojzsis, Stephen

1996-01-01

The recent claim to have identified possible signs of ancient life on Mars has been widely publicized and discussed. The authors conceded that none of the half-dozen pieces of evidence adduced in their paper individually provided strong support for extraterrestrial life, though they argued that the pieces added up to a case worth considering. Most - perhaps all - of the observed phenomena have counterparts in the inorganic world, so even the combination does not make a compelling case that there was ever life on Mars. Nevertheless, the importance of the problem has justified bringing the results to general attention. The paper has focussed interest on the origin and possible ubiquity of life, and on how we can design techniques capable of giving a more definitive answer to the question of whether there is, or has ever been, life elsewhere in the Universe.

Project Cyclops: a Design Study of a System for Detecting Extraterrestrial Intelligent Life

Science.gov (United States)

1972-01-01

The requirements in hardware, manpower, time and funding to conduct a realistic effort aimed at detecting the existence of extraterrestrial intelligent life are examined. The methods used are limited to present or near term future state-of-the-art techniques. Subjects discussed include: (1) possible methods of contact, (2) communication by electromagnetic waves, (3) antenna array and system facilities, (4) antenna elements, (5) signal processing, (6) search strategy, and (7) radio and radar astronomy.

Extraterrestrial material analysis: loss of amino acids during liquid-phase acid hydrolysis

Science.gov (United States)

Buch, Arnaud; Brault, Amaury; Szopa, Cyril; Freissinet, Caroline

2015-04-01

Searching for building blocks of life in extraterrestrial material is a way to learn more about how life could have appeared on Earth. With this aim, liquid-phase acid hydrolysis has been used, since at least 1970 , in order to extract amino acids and other organic molecules from extraterrestrial materials (e.g. meteorites, lunar fines) or Earth analogues (e.g. Atacama desert soil). This procedure involves drastic conditions such as heating samples in 6N HCl for 24 h, either under inert atmosphere/vacuum, or air. Analysis of the hydrolyzed part of the sample should give its total (free plus bound) amino acid content. The present work deals with the influence of the 6N HCl hydrolysis on amino acid degradation. Our experiments have been performed on a standard solution of 17 amino acids. After liquid-phase acid hydrolysis (6N HCl) under argon atmosphere (24 h at 100°C), the liquid phase was evaporated and the dry residue was derivatized with N-Methyl-N-(t-butyldimethylsilyl)trifluoroacetamide (MTBSTFA) and dimethylformamide (DMF), followed by gas chromatography-mass spectrometry analysis. After comparison with derivatized amino acids from the standard solution, a significant reduction of the chromatographic peak areas was observed for most of the amino acids after liquid-phase acid hydrolysis. Furthermore, the same loss pattern was observed when the amino acids were exposed to cold 6N HCl for a short amount of time. The least affected amino acid, i.e. glycine, was found to be 73,93% percent less abundant compared to the non-hydrolyzed standard, while the most affected, i.e. histidine, was not found in the chromatograms after hydrolysis. Our experiments thereby indicate that liquid-phase acid hydrolysis, even under inert atmosphere, leads to a partial or total loss of all of the 17 amino acids present in the standard solution, and that a quick cold contact with 6N HCl is sufficient to lead to a loss of amino acids. Therefore, in the literature, the reported increase

Extraterrestrial amino acids in Cretaceous/Tertiary boundary sediments at Stevns Klint, Denmark

Science.gov (United States)

Zhao, Meixun; Bada, Jeffrey L.

1989-06-01

SINCE the discovery1 nearly a decade ago that Cretaceous/Tertiary (K/T) boundary layers are greatly enriched in iridium, a rare element in the Earth's crust, there has been intense controversy on the relationship between this Ir anomaly and the massive extinction of organisms ranging from dinosaurs to marine plankton that characterizes the K/T boundary. Convincing evidence suggests that both the Ir spike and the extinction event were caused by the collision of a large bolide (>10 km in diameter) with the Earth1-11. Alternative explanations claim that extensive, violent volcanism12-14 can account for the Ir, and that other independent causes were responsible for the mass extinctions15,16. We surmise that the collision of a massive extraterrestrial object with the Earth may have produced a unique organic chemical signature because certain meteorites, and probably comets, contain organic compounds which are either rare or non-existent on the Earth17. In contrast, no organic compounds would be expected to be associated with volcanic processes. Here we find that K/T boundary sediments at Stevns Klint, Denmark, contain both α-amino-isobutyric acid [AIB, (CH3)2CNH2COOH] and racemic isovaline [ISOVAL, CH3CH2(CH3)CNH2COOH], two amino acids that are exceedingly rare on the Earth but which are major amino acids in carbonaceous chondrites17,18. An extraterrestrial source is the most reasonable explanation for the presence of these amino acids.

Older Siblings Influence Younger Siblings' Motor Development

Science.gov (United States)

Berger, Sarah E.; Nuzzo, Katie

2008-01-01

Evidence exists for two competing theories about the effects of having an older sibling on development. Previous research has found that having an older sibling has both advantages and disadvantages for younger siblings' development. This study examined whether and how older siblings influenced the onset of their own younger siblings' motor…

Colorectal cancer in younger population: our experience

International Nuclear Information System (INIS)

Amini, A.Q.; Samo, K.A.; Memon, A.S.

2013-01-01

Objective: To promote awareness regarding increased occurrence of colorectal cancer in younger population and its clinicopathological features compared to older patients. Methods: The cross-sectional study was conducted from February 2010 to January 2011 on patients with diagnosis of colorectal carcinoma admitted through emergency or outpatient departments to Surgical Unit 5, Civil Hospital, Karachi. Data regarding age, gender, presentation, site of tumour, surgery performed and Dukes staging was collected and analysed. Results: A total of 23 patients were operated during the study period: 13 (56.52%) males and 10 (43.47%) females. Of them 12 (52.17%) were below the age of 40 years, while 3 (13.04%) patients were in the 11-20 age group. In 7 (30.4%) patients, tumour was irresectable at the time of presentation so a palliative procedure (diversion colostomy or ileostomy) was performed. There was a higher proportion of younger patients with metastatic disease at the time of presentation (n=9; 75%) while 10 out of 12 patients in the younger age group (83.3%) had a tumour of left colon, particularly rectum. Conclusion: Although colorectal cancer is usually a disease of older patients, it is increasingly becoming more common in younger population. Data suggests a leftward distribution for colorectal carcinoma and that younger patients present with more advanced disease and poorer prognosis. (author)

Extraterrestrial Nucleobases in Carbonaceous Chondrites

Science.gov (United States)

Martins, Z.; Botta, O.; Fogel, M.; Sephton, M.; Glavin, D.; Watson, J.; Dworkin, J.; Schwartz, A.; Ehrenfreund, P.

. Our stable carbon isotope measurements clearly demonstrate that the nucleobases in the Murchison meteorite are indigenous to the meteorite, and clearly differ from the values determined for the terrestrial nucleobases measured in the soil collected at the impact site. These results support the hypothesis that nucleobases were exogenously delivered to the early Earth, and may have been important for the prebiotic chemistry on our young planet. With regard to the detection of traces of life on other planets such as Mars it is essential to characterize organic materials that have been exogenously delivered to the early planets. The analysis of the composition and isotopic fractionation of extraterrestrial material using complementary techniques can provide crucial insights into the formation of our Solar System, extraterrestrial delivery processes and subsequent addition and incorporation into the carbonaceous material available on the young planets. Ultimately, these parameters form an essential reference point for interpreting biosignatures that may be left in the ancient rock record on a planetary body. References: [1] Hayatsu R. et al. 1975. Geochimica et Cosmochimica Acta 39: 471- 488. [2] Folsome C. E. et al. 1971. Nature 232: 108-109. [3] Stoks P. G. & Schwartz A. W. 1979. Nature 282: 709-710. [4] Stoks P.G. & Schwartz A. W. 1981. Geochimica et Cosmochimica Acta 45: 563-569. [5] Shimoyama A. et al. 1990. Geochemical Journal 24: 343-348. [6] Martins Z. et al. 2004. Meteoritics & Planetary Science 39: A5145. 2

Development of extraterrestrial intelligence and physical laws

Science.gov (United States)

Troitskij, V. S.

This paper considers the restrictions imposed by physical laws on the development of life and intelligence in the form of extraterrestrial civilizations. For this purpose intelligence is defined as the community of intelligent beings, joined by the exchange of mass, energy and information both between themselves and with the external medium. Due to the limitation of the velocity of exchange of information and, in particular, mass and energy exchange, the dimensions of the intelligence cannot exceed some light days, i.e. they are limited by the habitable zone about their star. It is shown that the energy consumption should not exceed the energy output of their star for the sake of preserving the cosmic near-star zone of life from energetic pollution. With the above restrictions of the energy product it takes millions of years to create an omnidirectional beacon-transmitter signals from which would be received by the contemporary antennas in all our Galaxy. It is realistic to create an omnidirectional beacon operating in the range of no more than 100-1000 light years.

A Review of Extra-Terrestrial Mining Concepts

Science.gov (United States)

Mueller, R. P.; van Susante, P. J.

2012-01-01

Outer space contains a vast amount of resources that offer virtually unlimited wealth to the humans that can access and use them for commercial purposes. One of the key technologies for harvesting these resources is robotic mining of regolith, minerals, ices and metals. The harsh environment and vast distances create challenges that are handled best by robotic machines working in collaboration with human explorers. Humans will benefit from the resources that will be mined by robots. They will visit outposts and mining camps as required for exploration, commerce and scientific research, but a continuous presence is most likely to be provided by robotic mining machines that are remotely controlled by humans. There have been a variety of extra-terrestrial robotic mining concepts proposed over the last 40 years and this paper will attempt to summarize and review concepts in the public domain (government, industry and academia) to serve as an informational resource for future mining robot developers and operators. The challenges associated with these concepts will be discussed and feasibility will be assessed. Future needs associated with commercial efforts will also be investigated.

The need for operating guidelines and a decision making framework applicable to the discovery of non-intelligent extraterrestrial life

Science.gov (United States)

Race, Margaret S.; Randolph, Richard O.

While formal principles have been adopted for the eventuality of detecting intelligent life in our galaxy (SETI Principles), no such guidelines exist for the discovery of non-intelligent extraterrestrial life within the solar system. Current scientifically based planetary protection policies for solar system exploration address how to undertake exploration, but do not provide clear guidance on what to do if and when life is detected. Considering that martian life could be detected under several different robotic and human exploration scenarios in the coming decades, it is appropriate to anticipate how detection of non-intelligent, microbial life could impact future exploration missions and activities, especially on Mars. This paper discusses a proposed set of interim guidelines based loosely on the SETI Principles and addresses issues extending from the time of discovery through future handling and treatment of extraterrestrial life on Mars or elsewhere. Based on an analysis of both scientific and ethical considerations, there is a clear need for developing operating protocols applicable at the time of discovery and a decision making framework that anticipates future missions and activities, both robotic and human. There is growing scientific confidence that the discovery of extraterrestrial life in some form is nearly inevitable. If and when life is discovered beyond Earth, non-scientific dimensions may strongly influence decisions about the nature and scope of future missions and activities. It is appropriate to encourage international discussion and consideration of the issues prior to an event of such historical significance.

Obesity and sexual dysfunction in younger Danish men

DEFF Research Database (Denmark)

Andersen, Ingelise; Heitman, B. L.; Wagner, Gorm

2008-01-01

INTRODUCTION: Proportion of populations that are overweight and obese are on the rise and generally affecting more than 50% of the adult Western male population. It is, therefore, of interest to look at possible associations between obesity and sexual function in a homogeneous population. AIM......: To examine a possible association between sexual disorders (erectile dysfunction, ejaculatory disorders, and sexual desire disorders) and obesity among younger men born and living in Denmark. METHODS: A community-based cross-sectional study of sexual health among Danish younger men. Questionnaires were...... the younger obese nonsmokers than obese smokers. Premature ejaculation, retarded ejaculation, and sexual desire disorders were all unrelated to overweight or obesity. CONCLUSION: Obesity (BMI > or = 30 kg/m(2)) seems associated with ED among younger men aged 20-45 years. Health programs directed toward...

Inflation-Theory Implications for Extraterrestrial Visitation

Science.gov (United States)

Deardoff, J.; Haisch, B.; Maccabee, B.; Puthoff, H. E.

It has recently been argued that anthropic reasoning applied to inflation theory reinforces the prediction that we should find ourselves part of a large, galaxy-sized civilisation, thus strengthening Fermi's paradox concerning `Where are they?' Furthermore, superstring and M-brane theory allow for the possibility of parallel universes, some of which in principle could be habitable. In addition, discussion of such exotic transport concepts as `traversable wormholes' now appears in the rigorous physics literature. As a result, the `We are alone' solution to Fermi's paradox, based on the constraints of earlier 20th century viewpoints, appears today to be inconsistent with new developments in our best current physics and astrophysics theories. Therefore we reexamine and reevaluate the present assumption that extraterrestrials or their probes are not in the vicinity of Earth, and argue instead that some evidence of their presence might be found in certain high-quality UFO reports. This study follows up on previous arguments that (1) interstellar travel for advanced civilizations is not a priori ruled out by physical principles and therefore may be practicable, and (2) such advanced civilisations may value the search for knowledge from uncontaminated species more than direct, interspecies communication, thereby accounting for apparent covertness regarding their presence.

If the universe is teeming with aliens where is everybody? fifty solutions to the Fermi paradox and the problem of extraterrestrial life

CERN Document Server

Webb, Stephen

2002-01-01

Given the fact that there are perhaps 400 million stars in our Galaxy alone, and perhaps 400 million galaxies in the Universe, it stands to reason that somewhere out there, in the 14-billion-year-old cosmos, there is or once was a civilization at least as advanced as our own. The sheer enormities of the numbers almost demand that we accept the truth of this hypothesis. Why, then, have we encountered no evidence, no messages, no artifacts of these extraterrestrials? Webb discusses in detail the 50 most cogent and intriguing solutions to Fermi's famous paradox: If the numbers strongly point to the existence of extraterrestrial civilizations, why have we found no evidence of them?

Amino Acids from Icy Amines: A Radiation-Chemical Approach to Extraterrestrial Synthesis

Science.gov (United States)

Dworkin, J. P.; Moore, M. H.

2010-01-01

Detections of amino acids in meteorites go back several decades, with at least 100 such compounds being reported for the Murchison meteorite alone. The presence of these extraterrestrial molecules raises questions as to their formation, abundance, thermal stability, racemization, and possible subsequent reactions. Although all of these topics have been studied in laboratories, such work often involves many variables and unknowns. This has led us to seek out model systems with which to uncover reaction products, test chemical predictions, and sited light on underlying reaction mechanisms. This presentation will describe one such study, focusing on amino-acid formation in ices.

Inferring the provenance of an alien species with DNA barcodes: the neotropical butterfly Dryas iulia in Thailand.

Science.gov (United States)

Burg, Noah A; Pradhan, Ashman; Gonzalez, Rebecca M; Morban, Emely Z; Zhen, Erica W; Sakchoowong, Watana; Lohman, David J

2014-01-01

The Neotropical butterfly Dryas iulia has been collected from several locations in Thailand and Malaysia since 2007, and has been observed breeding in the wild, using introduced Passiflora foetida as a larval host plant. The butterfly is bred by a butterfly house in Phuket, Thailand, for release at weddings and Buddhist ceremonies, and we hypothesized that this butterfly house was the source of wild, Thai individuals. We compared wing patterns and COI barcodes from two, wild Thai populations with individuals obtained from this butterfly house. All Thai individuals resemble the subspecies D. iulia modesta, and barcodes from wild and captive Thai specimens were identical. This unique, Thai barcode was not found in any of the 30 specimens sampled from the wild in the species' native range, but is most similar to specimens from Costa Rica, where many exporting butterfly farms are located. These data implicate the butterfly house as the source of Thailand's wild D. iulia populations, which are currently so widespread that eradication efforts are unlikely to be successful.

Inferring the provenance of an alien species with DNA barcodes: the neotropical butterfly Dryas iulia in Thailand.

Directory of Open Access Journals (Sweden)

Noah A Burg

Full Text Available The Neotropical butterfly Dryas iulia has been collected from several locations in Thailand and Malaysia since 2007, and has been observed breeding in the wild, using introduced Passiflora foetida as a larval host plant. The butterfly is bred by a butterfly house in Phuket, Thailand, for release at weddings and Buddhist ceremonies, and we hypothesized that this butterfly house was the source of wild, Thai individuals. We compared wing patterns and COI barcodes from two, wild Thai populations with individuals obtained from this butterfly house. All Thai individuals resemble the subspecies D. iulia modesta, and barcodes from wild and captive Thai specimens were identical. This unique, Thai barcode was not found in any of the 30 specimens sampled from the wild in the species' native range, but is most similar to specimens from Costa Rica, where many exporting butterfly farms are located. These data implicate the butterfly house as the source of Thailand's wild D. iulia populations, which are currently so widespread that eradication efforts are unlikely to be successful.

An Earth-Based Equivalent Low Stretch Apparatus to Assess Material Flammability for Microgravity & Extraterrestrial Fire-Safety Applications

Science.gov (United States)

Olson, S. L.; Beeson, H.; Haas, J.

2001-01-01

One of the performance goals for NASA's enterprise of Human Exploration and Development of Space (HEDS) is to develop methods, data bases, and validating tests for material flammability characterization, hazard reduction, and fire detection/suppression strategies for spacecraft and extraterrestrial habitats. This work addresses these needs by applying the fundamental knowledge gained from low stretch experiments to the development of a normal gravity low stretch material flammability test method. The concept of the apparatus being developed uses the low stretch geometry to simulate the conditions of the extraterrestrial environment through proper scaling of the sample dimensions to reduce the buoyant stretch in normal gravity. The apparatus uses controlled forced-air flow to augment the low stretch to levels which simulate Lunar or Martian gravity levels. In addition, the effect of imposed radiant heat flux on material flammability can be studied with the cone heater. After breadboard testing, the apparatus will be integrated into NASA's White Sands Test Facility's Atmosphere-Controlled Cone Calorimeter for evaluation as a new materials screening test method.

Framing effects in younger and older adults.

Science.gov (United States)

Kim, Sunghan; Goldstein, David; Hasher, Lynn; Zacks, Rose T

2005-07-01

A growing literature on decision making in older adults suggests that they are more likely to use heuristic processing than are younger adults. We assessed this tendency in the context of a framing effect, a decision-making phenomenon whereby the language used to describe options greatly influences the decision maker's choice. We compared decision making under a standard ("heuristic") condition and also under a "justification" condition known to reduce reliance on heuristics. In the standard condition, older adults were more susceptible than younger adults to framing but the two groups did not differ when participants were asked to provide a justification. Thus, although older adults may spontaneously rely more on heuristic processing than younger adults, they can be induced to take a more systematic approach to decision making.

Biotic turnover rates during the Pleistocene-Holocene transition

Science.gov (United States)

Stivrins, Normunds; Soininen, Janne; Amon, Leeli; Fontana, Sonia L.; Gryguc, Gražyna; Heikkilä, Maija; Heiri, Oliver; Kisielienė, Dalia; Reitalu, Triin; Stančikaitė, Miglė; Veski, Siim; Seppä, Heikki

2016-11-01

The Northern Hemisphere is currently warming at the rate which is unprecedented during the Holocene. Quantitative palaeoclimatic records show that the most recent time in the geological history with comparable warming rates was during the Pleistocene-Holocene transition (PHT) about 14,000 to 11,000 years ago. To better understand the biotic response to rapid temperature change, we explore the community turnover rates during the PHT by focusing on the Baltic region in the southeastern sector of the Scandinavian Ice Sheet, where an exceptionally dense network on microfossil and macrofossil data that reflect the biotic community history are available. We further use a composite chironomid-based summer temperature reconstruction compiled specifically for our study region to calculate the rate of temperature change during the PHT. The fastest biotic turnover in the terrestrial and aquatic communities occurred during the Younger Dryas-Holocene shift at 11,700 years ago. This general shift in species composition was accompanied by regional extinctions, including disappearance of mammoth (Mammuthus primigenius) and reindeer (Rangifer tarandus) and many arctic-alpine plant taxa, such as Dryas octopetala, Salix polaris and Saxifraga aizoides, from the region. This rapid biotic turnover rate occurred when the rate of warming was 0.17 °C/decade, thus slightly lower than the current Northern Hemisphere warming of 0.2 °C/decade. We therefore conclude that the Younger Dryas-Holocene shift with its rapid turnover rates and associated regional extinctions represents an important palaeoanalogue to the current high latitude warming and gives insights about the probable future turnover rates and patterns of the terrestrial and aquatic ecosystem change.

Space nuclear power systems for extraterrestrial basing

International Nuclear Information System (INIS)

Lance, J.R.; Chi, J.W.H.

1989-01-01

Previous studies of nuclear and non-nuclear power systems for lunar bases are compared with recent studies by others. Power levels from tens of kW e for early base operation up to 2000 kW e for a self-sustaining base with a Closed Environment Life Support System (CELSS) are considered. Permanent lunar or Martian bases will require the use of multiple nuclear units connected to loads with a power transmission and distribution system analogous to earth-based electric utility systems. A methodology used for such systems is applied to the lunar base system to examine the effects of adding 100 kW e SP-100 class and/or larger nuclear units when a reliability criterion is imposed. The results show that resource and logistic burdens can be reduced by using 1000 kW e units early in the base growth scenario without compromising system reliability. Therefore, both technologies being developed in two current programs (SP-100 and NERVA Derivative Reactor (NDR) technology for space power) can be used effectively for extraterrestrial base power systems. Recent developments in NDR design that result in major reductions in reactor mass are also described. (author)

New Extraterrestrial Signature of the Insoluble Organic Matter of the Orgueil, Murchison and Tagish Lake Meteorites as Revealed by Electron Paramagnetic Resonance

Science.gov (United States)

Binet, L.; Gourier, D.; Derenne, S.; Robert, F.; Ciofini, I.

2003-03-01

EPR of the insoluble organic matter (IOM) of three chondrites revealed heterogeneously spread radicals including diradicaloids. These features not observed in terrestrial kerogens appear as an extraterrestrial signature of the chondritic IOM.

Individually-Personal Peculiarities of Younger Preschoolers’ Speech

Directory of Open Access Journals (Sweden)

M E Novikova

2013-12-01

Full Text Available Studying the speech of the younger preschoolers is a major factor in designing educational methods and preparing children for school. There exist individual and gender differences in the way children acquire speech skills. Word comprehension and idea interpretation depend on the child’s upbringing, his or her environment, the interaction within the family. This article submits the research data obtained from the study of the individual peculiarities of the younger preschool children’s speech.

A Review of Extra-Terrestrial Mining Robot Concepts

Science.gov (United States)

Mueller, Robert P.; Van Susante, Paul J.

2011-01-01

Outer space contains a vast amount of resources that offer virtually unlimited wealth to the humans that can access and use them for commercial purposes. One of the key technologies for harvesting these resources is robotic mining of regolith, minerals, ices and metals. The harsh environment and vast distances create challenges that are handled best by robotic machines working in collaboration with human explorers. Humans will benefit from the resources that will be mined by robots. They will visit outposts and mining camps as required for exploration, commerce and scientific research, but a continuous presence is most likely to be provided by robotic mining machines that are remotely controlled by humans. There have been a variety of extra-terrestrial robotic mining concepts proposed over the last 100 years and this paper will attempt to summarize and review concepts in the public domain (government, industry and academia) to serve as an informational resource for future mining robot developers and operators. The challenges associated with these concepts will be discussed and feasibility will be assessed. Future needs associated with commercial efforts will also be investigated.

Comparison of the Raman spectra of ion irradiated soot and collected extraterrestrial carbon

Science.gov (United States)

Brunetto, R.; Pino, T.; Dartois, E.; Cao, A.-T.; d'Hendecourt, L.; Strazzulla, G.; Bréchignac, Ph.

2009-03-01

We use a low pressure flame to produce soot by-products as possible analogues of the carbonaceous dust present in diverse astrophysical environments, such as circumstellar shells, diffuse interstellar medium, planetary disks, as well as in our own Solar System. Several soot samples, displaying an initial chemical diversity from aromatic to aliphatic dominated material, are irradiated with 200-400 keV H +, He +, and Ar ++ ions, with fluences comprised between 10 14 and 10 16 ions/cm 2, to simulate expected radiation induced modification on extraterrestrial carbon. The evolution of the samples is monitored using Raman spectroscopy, before, during, and after irradiation. A detailed analysis of the first- and second-order Raman spectra is performed, using a fitting combination of Lorentzian and/or Gaussian-shaped bands. Upon irradiation, the samples evolve toward an amorphous carbon phase. The results suggest that the observed variations are more related to vacancy formation than ionization processes. A comparison with Raman spectra of extraterrestrial organic matter and other irradiation experiments of astrophysically relevant carbonaceous materials is presented. The results are consistent with previous experiments showing mostly amorphization of various carbonaceous materials. Irradiated soots have Raman spectra similar to those of some meteorites, IDPs, and Comet Wild 2 grains collected by the Stardust mission. Since the early-Sun expected irradiation fluxes sufficient for amorphization are compatible with accretion timescales, our results support the idea that insoluble organic matter (IOM) observed in primitive meteorites has experienced irradiation-induced amorphization prior to the accretion of the parent bodies, emphasizing the important role played by early solar nebula processing.

The experience of demanding work environments in younger workers

DEFF Research Database (Denmark)

Winding, Trine Nøhr; Labriola, Merete; Nohr, Ellen Aagaard

2015-01-01

younger workers aged 20-21. The psychosocial work environment was in general good but younger workers experienced more demanding physical work than the general working population. Overall, individual as well as family factors had a limited impact on their assessment of the work environment. Low self-esteem...... at age 20-21. The psychosocial work environment experienced by younger workers was generally good, but vulnerable young people may need special attention to protect them from or prepare them for psychosocially demanding jobs later in life....

The search for extraterrestrial life: Recent developments; Proceedings of the Symposium, Boston University, MA, June 18-21, 1984

Science.gov (United States)

Papagiannis, M. D.

The conference presents papers on the history of the search for extraterrestrial life, the scientific rationale and methods used in the search for other planetary systems, the detection of distant planets with the Space Telescope, planetary searches using optical astrometric interferometers, and infrared spectral identification of complex organic molecules in interstellar grains. Also considered are universal protein ancestors from hydrogen cyanide and water, astronomical sources of polarized light and their role in determining molecular chirality on earth, the universal diagrams and life in the universe, the precambrian evolution of terrestrial life and a thermodynamic approach to the occurrance and appearance of galactic life forms. Papers are also presented on the Ohio Seti program, lunar reflections of terrestrial radio leakage, the multichannel spectrum analyzer, software implementation of detection algorithms for the MCSA, the Serendip II design, galactic colonization and competition in a young galactic disk, implications of ancient and future migrations, extraterrestrial intelligence, the inevitability and the possible structures of supercivilizations, planetary, interplanetary and interstellar organic matter, and universal aspects of biological evolution.

Flash pyrolysis of adsorbed aromatic organic acids on carbonate minerals: Assessing the impact of mineralogy for the identification of organic compounds in extraterrestrial bodies

Science.gov (United States)

Zafar, R.

2017-12-01

The relationship between minerals and organics is an essential factor in comprehending the origin of life on extraterrestrial bodies. So far organic molecules have been detected on meteorites, comets, interstellar medium and interplanetary dust particles. While on Mars, organic molecules may also be present as indicated by the Sample Analysis at Mars (SAM) instrument suite on the Curiosity Rover in Martian sediments. Minerals including hydrated phyllosilicate, carbonate, and sulfate minerals have been confirmed in carbonaceous chondrites. The presence of phyllosilicate minerals on Mars has been indicated by in situ elemental analysis by the Viking Landers, remote sensing infrared observations and the presence of smectites in meteorites. Likewise, the presence of carbonate minerals on the surface of Mars has been indicated by both Phoenix Lander and Spirit Rover. Considering the fact that both mineral and organic matter are present on the surface of extraterrestrial bodies including Mars, a comprehensive work is required to understand the interaction of minerals with specific organic compounds. The adsorption of the organic molecule at water/mineral surface is a key process of concentrating organic molecules on the surface of minerals. Carboxylic acids are abundantly observed in extraterrestrial material such as meteorites and interstellar space. It is highly suspected that carboxylic acids are also present on Mars due to the average organic carbon infall rate of 108 kg/yr. Further aromatic organic acids have also been observed in carbonaceous chondrite meteorites. This work presents the adsorption of an aromatic carboxylic acid at the water/calcite interface and characterization of the products formed after adsorption via on-line pyrolysis. Adsorption and online pyrolysis results are used to gain insight into adsorbed aromatic organic acid-calcite interaction. Adsorption and online pyrolysis results are related to the interpretation of organic compounds identified

Searching for Extraterrestrial Intelligence SETI Past, Present, and Future

CERN Document Server

Shuch, H Paul

2011-01-01

This book is a collection of essays written by the very scientists and engineers who have led, and continue to lead, the scientific quest known as SETI, the search for extraterrestrial intelligence. Divided into three parts, the first section, ‘The Spirit of SETI Past’, written by the surviving pioneers of this then emerging discipline, reviews the major projects undertaken during the first 50 years of SETI science and the results of that research. In the second section, ‘The Spirit of SETI Present’, the present-day science and technology is discussed in detail, providing the technical background to contemporary SETI instruments, experiments, and analytical techniques, including the processing of the received signals to extract potential alien communications. In the third and final section, ‘The Spirit of SETI Future’, the book looks ahead to the possible directions that SETI will take in the next 50 years, addressing such important topics as interstellar message construction, the risks and assump...

the Ĝ infrared search for extraterrestrial civilizations with large energy supplies. II. Framework, strategy, and first result

International Nuclear Information System (INIS)

Wright, J. T.; Griffith, R. L.; Sigurdsson, S.; Povich, M. S.; Mullan, B.

2014-01-01

We describe the framework and strategy of the Ĝ infrared search for extraterrestrial civilizations with large energy supplies, which will use the wide-field infrared surveys of WISE and Spitzer to search for these civilizations' waste heat. We develop a formalism for translating mid-infrared photometry into quantitative upper limits on extraterrestrial energy supplies. We discuss the likely sources of false positives, how dust can and will contaminate our search, and prospects for distinguishing dust from alien waste heat. We argue that galaxy-spanning civilizations may be easier to distinguish from natural sources than circumstellar civilizations (i.e., Dyson spheres), although GAIA will significantly improve our capability to identify the latter. We present a zeroth order null result of our search based on the WISE all-sky catalog: we show, for the first time, that Kardashev Type III civilizations (as Kardashev originally defined them) are very rare in the local universe. More sophisticated searches can extend our methodology to smaller waste heat luminosities, and potentially entirely rule out (or detect) both Kardashev Type III civilizations and new physics that allows for unlimited 'free' energy generation.

the Ĝ infrared search for extraterrestrial civilizations with large energy supplies. II. Framework, strategy, and first result

Energy Technology Data Exchange (ETDEWEB)

Wright, J. T.; Griffith, R. L.; Sigurdsson, S. [Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA, 16802 (United States); Povich, M. S. [Department of Physics and Astronomy, California State Polytechnic University, Pomona, 3801 West Temple Avenue, Pomona, CA 91768 (United States); Mullan, B. [Blue Marble Space Institution of Science, P.O. Box 85561, Seattle, WA 98145-1561 (United States)

2014-09-01

We describe the framework and strategy of the Ĝ infrared search for extraterrestrial civilizations with large energy supplies, which will use the wide-field infrared surveys of WISE and Spitzer to search for these civilizations' waste heat. We develop a formalism for translating mid-infrared photometry into quantitative upper limits on extraterrestrial energy supplies. We discuss the likely sources of false positives, how dust can and will contaminate our search, and prospects for distinguishing dust from alien waste heat. We argue that galaxy-spanning civilizations may be easier to distinguish from natural sources than circumstellar civilizations (i.e., Dyson spheres), although GAIA will significantly improve our capability to identify the latter. We present a zeroth order null result of our search based on the WISE all-sky catalog: we show, for the first time, that Kardashev Type III civilizations (as Kardashev originally defined them) are very rare in the local universe. More sophisticated searches can extend our methodology to smaller waste heat luminosities, and potentially entirely rule out (or detect) both Kardashev Type III civilizations and new physics that allows for unlimited 'free' energy generation.

The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies. II. Framework, Strategy, and First Result

Science.gov (United States)

Wright, J. T.; Griffith, R. L.; Sigurdsson, S.; Povich, M. S.; Mullan, B.

2014-09-01

We describe the framework and strategy of the Ĝ infrared search for extraterrestrial civilizations with large energy supplies, which will use the wide-field infrared surveys of WISE and Spitzer to search for these civilizations' waste heat. We develop a formalism for translating mid-infrared photometry into quantitative upper limits on extraterrestrial energy supplies. We discuss the likely sources of false positives, how dust can and will contaminate our search, and prospects for distinguishing dust from alien waste heat. We argue that galaxy-spanning civilizations may be easier to distinguish from natural sources than circumstellar civilizations (i.e., Dyson spheres), although GAIA will significantly improve our capability to identify the latter. We present a zeroth order null result of our search based on the WISE all-sky catalog: we show, for the first time, that Kardashev Type III civilizations (as Kardashev originally defined them) are very rare in the local universe. More sophisticated searches can extend our methodology to smaller waste heat luminosities, and potentially entirely rule out (or detect) both Kardashev Type III civilizations and new physics that allows for unlimited "free" energy generation.

The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies. I. Background and Justification

Science.gov (United States)

Wright, J. T.; Mullan, B.; Sigurdsson, S.; Povich, M. S.

2014-09-01

We motivate the Ĝ infrared search for extraterrestrial civilizations with large energy supplies. We discuss some philosophical difficulties of the search for extraterrestrial intelligence (SETI), and how communication SETI circumvents them. We review "Dysonian SETI," the search for artifacts of alien civilizations, and find that it is highly complementary to traditional communication SETI; the two together might succeed where either one alone has not. We discuss the argument of Hart that spacefaring life in the Milky Way should be either galaxy-spanning or non-existent, and examine a portion of his argument that we call the "monocultural fallacy." We discuss some rebuttals to Hart that invoke sustainability and predict long Galaxy colonization timescales. We find that the maximum Galaxy colonization timescale is actually much shorter than previous work has found (energy supplies and argue that detectably large energy supplies can plausibly be expected to exist because life has the potential for exponential growth until checked by resources or other limitations, and intelligence implies the ability to overcome such limitations. As such, if Hart's thesis is correct, then searches for large alien civilizations in other galaxies may be fruitful; if it is incorrect, then searches for civilizations within the Milky Way are more likely to succeed than Hart argued. We review some past Dysonian SETI efforts and discuss the promise of new mid-infrared surveys, such as that of WISE.

PHILOSOPHICAL-ANTROPOLOGICAL ASPECTS OF A PROBLEM OF SEARCH EXTRA-TERRESTRIAL OF CIVILIZATIONS

Directory of Open Access Journals (Sweden)

A. T. Tshedrin

2013-09-01

Full Text Available Purpose. The fears express, that «METI-projects», which testify to existence of mankind as technicalgeneous of a civilization for highly advanced ETC of a Galaxy, can have the extremely negative consequences, and «SETI-projects» and received radiosignals can become the information weapon aggressive ETC. The analysis of these fears as complete sociocultural of a phenomenon, them philosophical-anthropological of measurement, sociocultural of the basis, the forms of their display are the purpose of clause. Methodology. Author used the social-communicative approach, methods of system and cluster analyses. Scientific innovation. Are opened philosophical-anthropological of measurement of a problem of life extra-terrestrial intelligents (ETI, the factors of statement of a problem of contacts with ETC in the modern form connected with spacing of scientific and technical activity of mankind, influence of processes globalization on philosophical-anthropological aspects of a problem ETC, connected with changes in the fundamental relation «the Man - World» are investigated. These processes conduct to growth of fears concerning unpredictable intervention in terrestrial sociocultural system of alien reason. The persuasive fears, connected with possible consequences of contacts with ETC, take the form of hypotheses rather extra-terrestrial of artificial intelligence (ETAI as potential subject of space contact. The positive and negative scripts of dialogue with ETAI, problem «of high quality of a signal» and «SETI-hacker», connected with ETAI as by the subject of space dialogue are considered. Conclusions. The further development of a problem of search ETC and establishment of contacts with it will be connected, on the one hand to success in overcoming civilization of impasse, in which there was a mankind on a boundary ХХ – ХХI of centuries, and with another - deepening of revolution in cosmology, progress of observant astronomy, philosophical

Compound specific stable isotopes as probes for distinguishing the sources of biomolecules in terrestrial and extraterrestrial materials

Science.gov (United States)

Engel, M. H.; Macko, S. A.

2003-04-01

Life on Earth consists of orderly arrangements of several key types of organic compounds (amino acids, sugars, fatty acids, nucleic bases) that are the building blocks of proteins, carbohydrates, lipids and nucleotides. Subsequent to death, macromolecules are commonly broken down to their molecular constituents or other similar scale components. Thus, in ancient terrestrial and extraterrestrial materials, it is far more likely to expect the presence of simple compounds such as amino acids rather than the proteins from which they were possibly derived. Given that amino acids, for example, are common components of all extinct and extant organisms, the challenge has been to develop methods for distinguishing their sources. Stable isotopes are powerful probes for determining the origins of organic matter. Amino acid constituents of all organisms on Earth exhibit characteristic stable isotope compositions owing to fractionations associated with their biosynthesis. These fractionations are distinct from those observed for amino acids formed by abiotic processes. Thus it should be possible to use isotopes as probes for determining whether amino acids in ancient rocks on Earth are biotic or abiotic, based on their relative isotopic compositions. Also, owing to differences in the isotope compositions of precursors, amino acids in extraterrestrial materials such as carbonaceous meteorites are moderately to substantially enriched in the heavy isotopes of C, N and H relative to terrestrial amino acids. Assuming that the isotope compositions of the gaseous components of, for example, the Martian atmosphere were distinct from Earth at such time when organic molecules may have formed, it should be possible to distinguish these components from terrestrial contaminants by determining their isotope compositions and/or those of their respective enantiomers. Also, if life as we know it existed on another planet such as Mars, fractionations characteristic of biosynthesis should be

Immunization Uptake in Younger Siblings of Children with Autism Spectrum Disorder

Science.gov (United States)

Kuwaik, Ghassan Abu; Roberts, Wendy; Zwaigenbaum, Lonnie; Bryson, Susan; Smith, Isabel M.; Szatmari, Peter; Modi, Bonnie M.; Tanel, Nadia; Brian, Jessica

2014-01-01

Background: Parental concerns persist that immunization increases the risk of autism spectrum disorder, resulting in the potential for reduced uptake by parents of younger siblings of children with autism spectrum disorder ("younger sibs"). Objective: To compare immunization uptake by parents for their younger child relative to their…

Laboratory for Extraterrestrial Physics

Science.gov (United States)

Vondrak, Richard R. (Technical Monitor)

2001-01-01

The NASA Goddard Space Flight Center (GSFC) Laboratory for Extraterrestrial Physics (LEP) performs experimental and theoretical research on the heliosphere, the interstellar medium, and the magnetospheres and upper atmospheres of the planets, including Earth. LEP space scientists investigate the structure and dynamics of the magnetospheres of the planets including Earth. Their research programs encompass the magnetic fields intrinsic to many planetary bodies as well as their charged-particle environments and plasma-wave emissions. The LEP also conducts research into the nature of planetary ionospheres and their coupling to both the upper atmospheres and their magnetospheres. Finally, the LEP carries out a broad-based research program in heliospheric physics covering the origins of the solar wind, its propagation outward through the solar system all the way to its termination where it encounters the local interstellar medium. Special emphasis is placed on the study of solar coronal mass ejections (CME's), shock waves, and the structure and properties of the fast and slow solar wind. LEP planetary scientists study the chemistry and physics of planetary stratospheres and tropospheres and of solar system bodies including meteorites, asteroids, comets, and planets. The LEP conducts a focused program in astronomy, particularly in the infrared and in short as well as very long radio wavelengths. We also perform an extensive program of laboratory research, including spectroscopy and physical chemistry related to astronomical objects. The Laboratory proposes, develops, fabricates, and integrates experiments on Earth-orbiting, planetary, and heliospheric spacecraft to measure the characteristics of planetary atmospheres and magnetic fields, and electromagnetic fields and plasmas in space. We design and develop spectrometric instrumentation for continuum and spectral line observations in the x-ray, gamma-ray, infrared, and radio regimes; these are flown on spacecraft to study

The Implications of the Discovery of Extraterrestrial Life for Religion and Theology

Science.gov (United States)

Peters, Ted

2012-05-01

This paper asks about the future of religion: (1) Will confirmation of ETI cause terrestrial religion to collapse? "No" is the answer based upon a summary of the "Peters ETI Religious Crisis Survey." Then three questions are posed to the astrotheologian: (2) What is the scope of God's creation? (3) What can we expect when we encounter ETI? (4) Will contact with more advanced ETI diminish human dignity? The paper's thesis is that contact with extraterrestrial intelligence will expand the existing Christian vision that all of creation — including the 13.7 billion year history of the universe replete with all of God's creatures — is the gift of a loving and gracious God.

Preliminary limits on the flux of muon neutrinos from extraterrestrial point sources

International Nuclear Information System (INIS)

Bionta, R.M.; Blewitt, G.; Bratton, C.B.

1985-01-01

We present the arrival directions of 117 upward-going muon events collected with the IMB proton lifetime detector during 317 days of live detector operation. The rate of upward-going muons observed in our detector was found to be consistent with the rate expected from atmospheric neutrino production. The upper limit on the total flux of extraterrestrial neutrinos >1 GeV is 2 -sec. Using our data and a Monte Carlo simulation of high energy muon production in the earth surrounding the detector, we place limits on the flux of neutrinos from a point source in the Vela X-2 system of 2 -sec with E > 1 GeV. 6 refs., 5 figs

Christianity's Response to the Discovery of Extraterrestrial Intelligent Life: Insights from Science and Religion and the Sociology of Religion

Science.gov (United States)

Bertka, Constance M.

The question of whether or not extraterrestrial life exists and its potential impact for religions, especially Christianity, is an ancient one addressed in numerous historical publications. The contemporary discussion has been dominated by a few notable scientists from the SETI and astrobiology communities, and by a few Christian theologians active in the science and religion field. This discussion amounts to scientists outside of the faith tradition predicting the demise of Christianity if extraterrestrial intelligent life is discovered and theologians within the tradition predicting the enrichment and reformulation of Christian doctrine. Missing from this discussion is insight drawn more broadly from the science and religion field and from the sociology of religion. A consideration of how possibilities for relating science and religion are reflected in the US public's varied acceptance of the theory of evolution; the growth of Christianity in the Global South; and a revised theory of secularization which inversely correlates religiosity to existential security, gives credence to the proposal that the response from those outside of academia would be much more varied and uncertain.

Soil Radon In The Nigerian Younger Granites | Dewu | Nigerian ...

African Journals Online (AJOL)

... not had enough time to attain equilibrium with its daughters. In general, the results suggest that with proper control, soil radon measurements over the Younger Granite can be used for uranium exploration in the region. Keywords: Radon, younger granite, soil uranium, half-lifeand thorium. Nigerian Journal of Physics Vol.

If the Universe is teeming with aliens... where is everybody? seventy-five solutions to the Fermi paradox and the problem of extraterrestrial life

CERN Document Server

Webb, Stephen

2015-01-01

Given the fact that there are perhaps 400 billion stars in our Galaxy alone, and perhaps 400 billion galaxies in the Universe, it stands to reason that somewhere out there, in the 14-billion-year-old cosmos, there is or once was a civilization at least as advanced as our own. The sheer enormity of the numbers almost demands that we accept the truth of this hypothesis. Why, then, have we encountered no evidence, no messages, no artifacts of these extraterrestrials? In this second, significantly revised and expanded edition of his widely popular book, Webb discusses in detail the (for now!) 75 most cogent and intriguing solutions to Fermi's famous paradox: If the numbers strongly point to the existence of extraterrestrial civilizations, why have we found no evidence of them?

The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies

Science.gov (United States)

Wright, Jason Thomas; Povich, Matthew; Griffith, Roger; Maldonado, Jessica; Sigurdsson, Steinn; Star Cartier, Kimberly

2015-08-01

The WISE and Spitzer large-area surveys of the mid-infrared sky bring a new opportunity to search for evidence of the energy supplies of very large extraterrestrial civilizations. If these energy supplies rival the output of a civilization's parent star (Kardashev Type II), or if a galaxy-spanning supercivilization's use rivals that of the total galactic luminosity (Type III), they would be detectable as anomolously mid-infrared-bright stars and galaxies, respectively. We have already performed the first search for this emission from Type III civilizations using the WISE all-sky survey, and put the first upper limits on them in the local universe, and discuss ways to improve on these limits. We also discuss some detectable forms of and limits on Type II civilizations in the Mliky Way.

Investigations in space-related molecular biology. [cryo-electron microscopic and diffraction studies on terrestrial and extraterrestrial specimens

Science.gov (United States)

Fernandez-Moran, H.; Pritzker, A. N.

1974-01-01

Improved instrumentation and preparation techniques for high resolution, high voltage cryo-electron microscopic and diffraction studies on terrestrial and extraterrestrial specimens are reported. Computer correlated ultrastructural and biochemical work on hydrated and dried cell membranes and related biological systems provided information on membrane organization, ice crystal formation and ordered water, RNA virus linked to cancer, lunar rock samples, and organometallic superconducting compounds. Apollo 11, 12, 14, and 15 specimens were analyzed

How Arousal Affects Younger and Older Adults' Memory Binding

Science.gov (United States)

Nashiro, Kaoru; Mather, Mara

2009-01-01

A number of recent studies have shown that associative memory for within-item features is enhanced for emotionally arousing items, whereas arousal-enhanced binding is not seen for associations between distinct items (for a review see Mather, 2007). The costs and benefits of arousal in memory binding have been examined for younger adults but not for older adults. The present experiment examined whether arousal would enhance younger and older adults' within-item and between-item memory binding. The results revealed that arousal improved younger adults' within-item memory binding but not that of older adults. Arousal worsened both groups' between-item memory binding. PMID:21240821

Discovery of ETI: Terrestrial and extraterrestrial legal implications

Science.gov (United States)

Fasan, Ernst

TheLegalSituationonEarth: The following international legal regulations seem to apply to the search for and the eventual detection of ETI: a) The "Space Treaty" of Oct. 10, 1967; b) The Liability Convention of Oct. 9, 1973; c) The Moon Agreement of Dec. 5, 1979; d) The International Telecommunication Convention. LegalRelationswithExtraterrestrials: We may expect the following characteristics of ETI: 1. life in the sense of influencing the environment by selection from more than one possibility; 2. intelligence in the sense of self-realization of free will; 3. existence in three dimensional space and a will to live. With this we can expect that each race in the universe may have the following interests regarding its own race: a) to preserve and continue its own life; b) to protect this life from damage and intrusion; c) possibly to expand the realms of its living space. Therefore, if we decide to "answer" ETI, we may want to transmit such legal-philosophical principles: 1. the principle of nonviolation; 2. the principle of equality; 3. the principle to recognize the will to live and the living space of any intelligent race.

Extra-terrestrial construction processes - Advancements, opportunities and challenges

Science.gov (United States)

Lim, Sungwoo; Prabhu, Vibha Levin; Anand, Mahesh; Taylor, Lawrence A.

2017-10-01

Government space agencies, including NASA and ESA, are conducting preliminary studies on building alternative space-habitat systems for deep-space exploration. Such studies include development of advanced technologies for planetary surface exploration, including an in-depth understanding of the use of local resources. Currently, NASA plans to land humans on Mars in the 2030s. Similarly, other space agencies from Europe (ESA), Canada (CSA), Russia (Roscosmos), India (ISRO), Japan (JAXA) and China (CNSA) have already initiated or announced their plans for launching a series of lunar missions over the next decade, ranging from orbiters, landers and rovers for extended stays on the lunar surface. As the Space Odyssey is one of humanity's oldest dreams, there has been a series of research works for establishing temporary or permanent settlement on other planetary bodies, including the Moon and Mars. This paper reviews current projects developing extra-terrestrial construction, broadly categorised as: (i) ISRU-based construction materials; (ii) fabrication methods; and (iii) construction processes. It also discusses four categories of challenges to developing an appropriate construction process: (i) lunar simulants; (ii) material fabrication and curing; (iii) microwave-sintering based fabrication; and (iv) fully autonomous and scaled-up construction processes.

Reward-Enhanced Memory in Younger and Older Adults

OpenAIRE

Julia Spaniol; Cécile Schain; Holly J. Bowen

2014-01-01

Objectives. We investigated how the anticipation of remote monetary reward modulates intentional episodic memory formation in younger and older adults. On the basis of prior findings of preserved reward–cognition interactions in aging, we predicted that reward anticipation would be associated with enhanced memory in both younger and older adults. On the basis of previous demonstrations of a time-dependent effect of reward anticipation on memory, we expected the memory enhancement to increase ...

Reply to van Hoesel et al.: Impact-related Younger Dryas boundary nanodiamonds from The Netherlands

Czech Academy of Sciences Publication Activity Database

Wittke, J. H.; Bunch, T. E.; Kennett, J. P.; Culleton, B. L.; Tankersley, K. B.; Daniel,, I. R., Jr.; Kloosterman, J. B.; Kletetschka, Günther; West, A.; Firestone, R. B.

2013-01-01

Roč. 110, č. 41 (2013), E3897-E3898 ISSN 0027-8424 Institutional support: RVO:67985831 Keywords : nanodiamonds * Clovis * radiocarbon dates * impact * Arlington Canyon Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 9.809, year: 2013

Widening Perspectives: The Intellectual and Social Benefits of Astrobiology (Regardless of Whether Extraterrestrial Life is Discovered or Not)

OpenAIRE

Crawford, Ian A.

2017-01-01

Astrobiology is usually defined as the study of the origin, evolution, distribution, and future of life in the universe. As such it is inherently interdisciplinary and cannot help but engender a worldview infused by cosmic and evolutionary perspectives. Both these attributes of the study of astrobiology are, and will increasingly prove to be, beneficial to society regardless of whether extraterrestrial life is discovered or not.

Widening perspectives: the intellectual and social benefits of astrobiology (regardless of whether extraterrestrial life is discovered or not)

Science.gov (United States)

Crawford, I. A.

2018-01-01

Astrobiology is usually defined as the study of the origin, evolution, distribution and future of life in the Universe. As such it is inherently interdisciplinary and cannot help but engender a worldview infused by cosmic and evolutionary perspectives. Both these attributes of the study of astrobiology are, and will increasingly prove to be, beneficial to society regardless of whether extraterrestrial life is discovered or not.

Structural Response of the Earth's Crust to an Extra-Terrestrial Source of Stress by Identifying its Characteristic Pattern

Science.gov (United States)

Dasgupta, B.

2016-12-01

The earth's crust is a geodynamic realm, which is constantly evolving. Due to its dynamic nature, the crust is constantly being subjected to remodelling. The earth's crustal response to stress is a result of isostatic compensation. The crust is also a living proof of yesteryears' dynamics. Extra-terrestrial agents of deformation refers to meteorites, asteroids etc. These are catastrophic events that influence a larger area (considering larger impact bodies). They effect the crust from outside, hence leave behind very specific structural signatures.Consider an extra-terrestrial object impacting the earth's crust. The problem can be broken down into 3 parts: Pre Impact (kinematics of the object and nature of surface of impact); Syn Impact (dissipation of energy and formation of crater); and Post Impact (structural response, geophysical anomalies and effect on biota)Upon impact, the projectile penetrates the earth's crust to a depth of twice its diameter. Shock waves generated due impact propagate in all possible directions. The reflected waves cause complete melting and vaporization of the impact body. At the same time, increased internal energy of the system melts the target rock. Depending on the thickness and density of crustal matter, its' interaction with the mantle is determined. Data collection from such impact sites is the first step towards its theoretical modeling. Integrating geophysical (seismic, magnetic), paleomagnetic, geochemical and geo-chronological data one can determine the kinematic parameters that governed the event. A working model that illustrates the crustal responses to extraterrestrial stress of extreme magnitude cannot be qualitative. Hence the most fundamental thing at this point is quantification of these parameters. The variables form a `mass-energy equation', a simple theorem in Classical Physics. This project is directed to give the equation its shape. The equation will be the foundation on which the simulation model will rest. Mass

How retellings shape younger and older adults' memories.

Science.gov (United States)

Barber, Sarah J; Mather, Mara

2014-04-01

The way a story is retold influences the way it is later remembered; after retelling an event in a biased manner people subsequently remember the event in line with their distorted retelling. This study tested the hypothesis that this should be especially true for older adults. To test this, older and younger adults retold a story to be entertaining, to be accurate, or did not complete an initial retelling. Later, all participants recalled the story as accurately as possible. On this final test younger adults were unaffected by how they had previously retold the story. In contrast, older adults had better memory for the story's content and structure if they had previously retold the story accurately. Furthermore, for older adults, greater usage of storytelling language during the retelling was associated with lower subsequent recall. In summary, retellings exerted a greater effect on memory in older, compared with younger, adults.

Older (but Not Younger) Siblings Facilitate False Belief Understanding.

Science.gov (United States)

Ruffman, Ted; Perner, Josef; Naito, Mika; Parkin, Lindsay; Clements, Wendy A.

1998-01-01

Four experiments and an analysis of pooled data from English and Japanese children show a linear increase in understanding false beliefs with number of older siblings; no such effect for children younger than 38 months; no helpful effect of younger siblings at any age; no effect of siblings' gender; and no helpful effect of siblings on a source…

The quest for extraterrestrial life: what about the viruses?

Science.gov (United States)

Griffin, Dale Warren

2013-01-01

Recently, viruses have been recognized as the most numerous entities and the primary drivers of evolution on Earth. Historically, viruses have been mostly ignored in the field of astrobiology due to the view that they are not alive in the classical sense and if encountered would not present risk due to their host-specific nature. What we currently know of viruses is that we are most likely to encounter them on other life-bearing planets; that while some are exquisitely host-specific, many viruses can utilize hundreds of different host species; that viruses are known to exist in our planet's most extreme environments; and that while many do not survive long outside their hosts, some can survive for extended periods, especially in the cold. In our quest for extraterrestrial life, we should be looking for viruses; and while any encountered may pose no risk, the possibility of an encounter with a virus capable of accessing multiple cell types exists, and any prospective contact with such an organism should be treated accordingly.

The Effects of Feedback on Memory Strategies of Younger and Older Adults.

Science.gov (United States)

Zhang, Fan; Zhang, Xin; Luo, Meng; Geng, Haiyan

2016-01-01

Existing literature suggests that feedback could effectively reduce false memories in younger adults. However, it is unclear whether memory performance in older adults also might be affected by feedback. The current study tested the hypothesis that older adults can use immediate feedback to adjust their memory strategy, similar to younger adults, but after feedback is removed, older adults may not be able to maintain using the memory strategy. Older adults will display more false memories than younger adults due to a reduction in attentional resources. In Study 1, both younger and older adults adjusted gist processing and item-specific processing biases based on the feedback given (i.e., biased and objective feedback). In Study 2 after the feedback was removed, only younger adults with full attention were able to maintain the feedback-shaped memory strategy; whereas, both younger adults with divided attention and older adults had increased false memories after feedback was removed. The findings suggest that environmental support helps older adults as well as younger adults to adopt a memory strategy that demands high attentional resources, but when the support is removed, older adults can no longer maintain such a strategy.

New insights in the bacterial spore resistance to extreme terrestrial and extraterrestrial factors

Science.gov (United States)

Moeller, Ralf; Horneck, Gerda; Reitz, Guenther

Based on their unique resistance to various space parameters, Bacillus endospores are one of the model systems used for astrobiological studies. The extremely high resistance of bacterial endospores to environmental stress factors has intrigued researchers since long time and many characteristic spore features, especially those involved in the protection of spore DNA, have already been uncovered. The disclosure of the complete genomic sequence of Bacillus subtilis 168, one of the often used astrobiological model system, and the rapid development of tran-scriptional microarray techniques have opened new opportunities of gaining further insights in the enigma of spore resistance. Spores of B. subtilis were exposed to various extreme ter-restrial and extraterrestrial stressors to reach a better understanding of the DNA protection and repair strategies, which them to cope with the induced DNA damage. Following physical stress factors of environmental importance -either on Earth or in space -were selected for this thesis: (i) mono-and polychromatic UV radiation, (ii) ionizing radiation, (iii) exposure to ultrahigh vacuum; and (iv) high shock pressures simulating meteorite impacts. To reach a most comprehensive understanding of spore resistance to those harsh terrestrial or simulated extraterrestrial conditions, a standardized experimental protocol of the preparation and ana-lyzing methods was established including the determination of the following spore responses: (i) survival, (ii) induced mutations, (iii) DNA damage, (iv) role of different repair pathways by use of a set of repair deficient mutants, and (v) transcriptional responses during spore germi-nation by use of genome-wide transcriptome analyses and confirmation by RT-PCR. From this comprehensive set of data on spore resistance to a variety of environmental stress parameters a model of a "built-in" transcriptional program of bacterial spores in response to DNA damaging treatments to ensure DNA restoration

Measuring the effect of an astrobiology course on student optimism regarding extraterrestrial life

Science.gov (United States)

Morgan, David L.

2017-07-01

Students in an introductory undergraduate Astrobiology course were given a pre/post-test based on the Drake Equation in an attempt to measure changes in their perceptions regarding the prevalence of life in the Galaxy after taking the course. The results indicated that, after taking the course, the students were considerably more optimistic, by a 2 to 1 margin or more, about the prospect of habitable planets, the origin of life, and the evolution of intelligence in other planetary systems. The results suggest that, while it may not be the explicit goal of an astrobiology course to change student beliefs about the abundance or rarity of extraterrestrial life, such changes in opinion can and do occur.

Perceptions of emotion and age among younger, midlife, and older adults.

Science.gov (United States)

Santorelli, Gennarina D; Ready, Rebecca E; Mather, Molly A

2018-03-01

Older adults report greater emotional well-being than younger persons, yet negative stereotypes about aging are pervasive. Little is known about age group perceptions of emotion in adulthood, particularly for familiar persons. Thus, this project determined perceptions of general affect in familiar younger and older adults. In two studies, participants (Study 1, younger adult n = 123, older adult n = 43; Study 2, younger adult n = 34, midlife adult n = 41, older adult n = 16) provided self-report data about their affect in general, as well as reported on the affect of a familiar younger person (aged 18--34) and a familiar older person (aged 65 or older). Emotion scales assessed high- and low-arousal positive and negative affect. Results suggest a less favorable perception of emotion experiences of older adults compared to younger adults. Specifically, participants of all age groups rated older adults as having lower positive emotions and higher negative emotions than is found in self-report data. Perceptions of emotion in older adulthood reflect stereotypes of negative functioning. Older adult participants were not immune to holding negative views about older adults. Negative perceptions about emotion experiences in later life may be detrimental to the physical and mental health of older adults.

Extraterrestrial Amino Acids Identified in Metal-Rich CH and CB Carbonaceous Chondrites from Antarctica

Science.gov (United States)

Burton, Aaron S.; Elsila, Jamie E.; Hein, Jason E.; Glavin, Daniel P.; Dworkin, Jason P.

2013-01-01

Carbonaceous chondrites contain numerous indigenous organic compounds and could have been an important source of prebiotic compounds required for the origin of life on Earth or elsewhere. Extraterrestrial amino acids have been reported in five of the eight groups of carbonaceous chondrites and are most abundant in CI, CM, and CR chondritesbut are also present in the more thermally altered CV and CO chondrites. We report the abundance, distribution, and enantiomeric and isotopic compositions of simple primary amino acids in six metal-rich CH and CB carbonaceous chondrites that have not previously been investigated for amino acids: Allan Hills (ALH) 85085 (CH3), Pecora Escarpment(PCA) 91467 (CH3), Patuxent Range (PAT) 91546 (CH3), MacAlpine Hills (MAC) 02675(CBb), Miller Range (MIL) 05082 (CB), and Miller Range (MIL) 07411 (CB). Amino acid abundances and carbon isotopic values were obtained by using both liquid chromatography time-of-flight mass spectrometry and fluorescence, and gas chromatography isotope ratiomass spectrometry. The (delta D, delta C-13, delta N-15) ratios of multiple amino acids fall outside of the terrestrial range and support their extraterrestrial origin. Extracts of CH chondrites were found to be particularly rich in amino acids (1316 parts per million, ppm) while CB chondrite extracts had much lower abundances (0.22 ppm). The amino acid distributions of the CH and CB chondrites were distinct from the distributions observed in type 2 and 3 CM and CR chondrites and contained elevated levels of beta-, gamma-, and delta-amino acids compared to the corresponding alpha-amino acids, providing evidence that multiple amino acid formation mechanisms were important in CH and CB chondrites.

Reward-enhanced memory in younger and older adults.

Science.gov (United States)

Spaniol, Julia; Schain, Cécile; Bowen, Holly J

2014-09-01

We investigated how the anticipation of remote monetary reward modulates intentional episodic memory formation in younger and older adults. On the basis of prior findings of preserved reward-cognition interactions in aging, we predicted that reward anticipation would be associated with enhanced memory in both younger and older adults. On the basis of previous demonstrations of a time-dependent effect of reward anticipation on memory, we expected the memory enhancement to increase with study-test delay. In Experiment 1, younger and older participants encoded a series of picture stimuli associated with high- or low-reward values. At test (24-hr postencoding), recognition hits resulted in either high or low monetary rewards, whereas false alarms were penalized to discourage guessing. Experiment 2 was similar to Experiment 1, but the study-test delay was manipulated within subjects (immediate vs 24hr). In Experiment 1, younger and older adults showed enhanced recognition for high-reward pictures compared with low-reward pictures. Experiment 2 replicated this finding and additionally showed that the effect did not extend to immediate recognition. The current findings provide support for a time-dependent mechanism of reward-based memory enhancement. They also suggest that aging leaves intact the positive influence of reward anticipation on intentional long-term memory formation. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Body Image in Younger Breast Cancer Survivors: A Systematic Review

Science.gov (United States)

Paterson, Carly; Lengacher, Cecile A.; Donovan, Kristine A.; Kip, Kevin E.; Tofthagen, Cindy S.

2015-01-01

Background Body image is a complex issue with the potential to impact many aspects of cancer survivorship, particularly for the younger breast cancer survivor. Objective The purpose of this review is to synthesize the current state of the science for body image in younger women with breast cancer. Intervention/Methods Combinations of the terms “body image,” “sexuality intervention,” “women,” “younger women,” and “breast cancer” were searched in the PubMed, PsycInfo, CINAHL, Web of Knowledge and Science Direct databases through January 2014. Inclusion criteria for this review were: 1) original research; 2) published in English from the year 2000 forward; 3) measuring body image as an outcome variable; and 4) results included reporting of age-related outcomes. Results Thirty-six articles met the inclusion criteria. The majority of studies were cross-sectional, with extensive variation in body image assessment tools. Age and treatment type had a significant impact on body image, and poorer body image was related to physical and psychological distress, sex and intimacy, and the partnered relationship among younger women. Only one intervention study found a significant improvement in body image post-intervention. Conclusions Findings suggest body image is a complex post-treatment concern for breast cancer survivors, particularly younger women. The findings of this review are limited by the high level of variation in the methods for assessing body image. Implications for Practice Further research of interventions to address body image concerns following treatment for breast cancer is warranted. Improvement of body image may improve the quality of life of younger breast cancer survivors. PMID:25881807

Comparison for younger and older adults: Stimulus temporal asynchrony modulates audiovisual integration.

Science.gov (United States)

Ren, Yanna; Ren, Yanling; Yang, Weiping; Tang, Xiaoyu; Wu, Fengxia; Wu, Qiong; Takahashi, Satoshi; Ejima, Yoshimichi; Wu, Jinglong

2018-02-01

Recent research has shown that the magnitudes of responses to multisensory information are highly dependent on the stimulus structure. The temporal proximity of multiple signal inputs is a critical determinant for cross-modal integration. Here, we investigated the influence that temporal asynchrony has on audiovisual integration in both younger and older adults using event-related potentials (ERP). Our results showed that in the simultaneous audiovisual condition, except for the earliest integration (80-110ms), which occurred in the occipital region for older adults was absent for younger adults, early integration was similar for the younger and older groups. Additionally, late integration was delayed in older adults (280-300ms) compared to younger adults (210-240ms). In audition‑leading vision conditions, the earliest integration (80-110ms) was absent in younger adults but did occur in older adults. Additionally, after increasing the temporal disparity from 50ms to 100ms, late integration was delayed in both younger (from 230 to 290ms to 280-300ms) and older (from 210 to 240ms to 280-300ms) adults. In the audition-lagging vision conditions, integration only occurred in the A100V condition for younger adults and in the A50V condition for older adults. The current results suggested that the audiovisual temporal integration pattern differed between the audition‑leading and audition-lagging vision conditions and further revealed the varying effect of temporal asynchrony on audiovisual integration in younger and older adults. Copyright © 2017 Elsevier B.V. All rights reserved.

'Being young': a qualitative study of younger nurses' experiences in the workplace.

Science.gov (United States)

Clendon, J; Walker, L

2012-12-01

The overall goal of this study was to obtain a greater understanding of the experiences of nurses aged under 30 in the New Zealand workforce with a view to developing age-appropriate retention strategies. Nurses aged under 30 constitute around 10% of the world's nursing workforce yet little is known about their experiences in the workplace. Poor retention of younger nurses is a cause for concern. The implications of the perceptions and needs of this generation of nurses must be considered in order to ensure effective succession planning. An explorative descriptive design framed within a broad qualitative methodology was utilized to explore experiences of younger nurses in the New Zealand workforce. Data were analysed thematically. Findings are reported under five themes: challenges of nursing, rewards of nursing, being young, coping and addressing generational differences. The study provides new knowledge about the experiences of younger nurses in the workforce and in particular the challenges facing younger Asian nurses. Managers and nurse leaders must address broader workforce issues as well as improving support for younger nurses to help improve younger nurse retention. Strategies designed to extend and challenge younger nurses in the workplace such as professional development and project work will also help, but will only be effective if nurses are given sufficient paid time to undertake this work. Being Asian provides added challenges for younger nurses in New Zealand and further research into the experiences of this subgroup is highly recommended. © 2012 The Authors. International Nursing Review © 2012 International Council of Nurses.

Elderly vs. younger problem drinker 'treatment' and recovery experiences.

Science.gov (United States)

Fitzgerald, J L; Mulford, H A

1992-09-01

To address the question of whether or not elderly problem drinkers experience any treatment contact discrimination or recovery rate disadvantages, the programme utilization and recovery rate experiences of a representative sample of older and younger persons arrested for drinking and driving (OWI) in Iowa were compared. Subjects were interviewed by phone or mail shortly after their OWI arrest and then again approximately 12 months later. Younger persons (18-54 years old) were compared with elderly persons (55 and over and 65 and over). The elderly subjects were also dichotomized as early onset (at least one problem drinking indicator occurred prior to age 55) or late onset (all problem drinking indicators occurred at age 55 or later). The elderly were as likely as, or more likely than, their younger counterparts to make a treatment contact, to remain in treatment and to recover.

On Younger Stakeholders and Decommissioning of Nuclear Facilities

Energy Technology Data Exchange (ETDEWEB)

Tyszkiewicz, Bogumila; Labor, Bea

2009-08-15

In modern democratic countries, information sharing and effective and open communication concerning dismantling and decommissioning of of nuclear facilities as well as the management of nuclear waste are essential for the task to build the confidence required for any further development of nuclear energy. At the same time, it is often perceived that all decision making processes about nuclear energy policies are probably increasingly influenced by public opinion. Nuclear and radiation safety Authorities have a clear role in this regard to provide unbiased information on any health and safety related issues. In order to meet this need, it is necessary for Authorities and others to understand the values and opinions of the citizens, and especially the younger ones. They hold the key to the future at the same time as their perspective on these issues is the least understood. The need of greater public participation in decision making is becoming increasingly recognised the scientific as well as the political community. Many activities are carried out in order to stimulate to higher levels of public involvement in decision making in this active research area. Younger citizens is a stakeholder group that is often excluded in decision- making processes. The existence of large gaps between the involvement of older and younger stakeholders in decision making processes needs to be addressed, since such imbalances might otherwise lead to unequal opportunities between generations and limit the future consumption level of the coming generations. Another demanding task for the present generation is to assure that appropriate financial resources are injected into the Swedish Nuclear Waste Fund. It will thereby be possible for coming generations to undertake efficient measures in the decommissioning and dismantling of older nuclear facilities. To undertake such measures in line with the environmental and health codex is essential. An appropriate balance in this regard must be

On Younger Stakeholders and Decommissioning of Nuclear Facilities

International Nuclear Information System (INIS)

Tyszkiewicz, Bogumila; Labor, Bea

2009-08-01

In modern democratic countries, information sharing and effective and open communication concerning dismantling and decommissioning of of nuclear facilities as well as the management of nuclear waste are essential for the task to build the confidence required for any further development of nuclear energy. At the same time, it is often perceived that all decision making processes about nuclear energy policies are probably increasingly influenced by public opinion. Nuclear and radiation safety Authorities have a clear role in this regard to provide unbiased information on any health and safety related issues. In order to meet this need, it is necessary for Authorities and others to understand the values and opinions of the citizens, and especially the younger ones. They hold the key to the future at the same time as their perspective on these issues is the least understood. The need of greater public participation in decision making is becoming increasingly recognised the scientific as well as the political community. Many activities are carried out in order to stimulate to higher levels of public involvement in decision making in this active research area. Younger citizens is a stakeholder group that is often excluded in decision- making processes. The existence of large gaps between the involvement of older and younger stakeholders in decision making processes needs to be addressed, since such imbalances might otherwise lead to unequal opportunities between generations and limit the future consumption level of the coming generations. Another demanding task for the present generation is to assure that appropriate financial resources are injected into the Swedish Nuclear Waste Fund. It will thereby be possible for coming generations to undertake efficient measures in the decommissioning and dismantling of older nuclear facilities. To undertake such measures in line with the environmental and health codex is essential. An appropriate balance in this regard must be

Enantiomeric excesses induced in amino acids by ultraviolet circularly polarized light irradiation of extraterrestrial ice analogs: A possible source of asymmetry for prebiotic chemistry

International Nuclear Information System (INIS)

Modica, Paola; De Marcellus, Pierre; D'Hendecourt, Louis Le Sergeant; Meinert, Cornelia; Meierhenrich, Uwe J.; Nahon, Laurent

2014-01-01

The discovery of meteoritic amino acids with enantiomeric excesses of the L-form (ee L ) has suggested that extraterrestrial organic materials may have contributed to prebiotic chemistry and directed the initial occurrence of the ee L that further led to homochirality of amino acids on Earth. A proposed mechanism for the origin of ee L in meteorites involves an asymmetric photochemistry of extraterrestrial ices by UV circularly polarized light (CPL). We have performed the asymmetric synthesis of amino acids on achiral extraterrestrial ice analogs by VUV CPL, investigating the chiral asymmetry transfer at two different evolutionary stages at which the analogs were irradiated (regular ices and/or organic residues) and at two different photon energies (6.6 and 10.2 eV). We identify 16 distinct amino acids and precisely measure the L-enantiomeric excesses using the enantioselective GC × GC-TOFMS technique in five of them: α-alanine, 2,3-diaminopropionic acid, 2-aminobutyric acid, valine, and norvaline, with values ranging from ee L = –0.20% ± 0.14% to ee L = –2.54% ± 0.28%. The sign of the induced ee L depends on the helicity and the energy of CPL, but not on the evolutionary stage of the samples, and is the same for all five considered amino acids. Our results support an astrophysical scenario in which the solar system was formed in a high-mass star-forming region where icy grains were irradiated during the protoplanetary phase by an external source of CPL of a given helicity and a dominant energy, inducing a stereo-specific photochemistry.

Space transportation and destination considerations for extraterrestrial disposal of radioactive waste

Science.gov (United States)

Zimmerman, A. V.; Thompson, R. L.; Lubick, R. J.

1973-01-01

A feasibility study is summarized of extraterrestrial (space) disposal of radioactive waste. The initial work on the evaluation and comparison of possible space destinations and launch vehicles is reported. Only current or planned space transportation systems were considered. The currently planned space shuttle was found to be more cost effective than current expendable launch vehicles, by about a factor of two. The space shuttle will require a third stage to perform the disposal missions. Depending on the particular mission this could be either a reusable space tug or an expendable stage such as a Centaur. Of the destinations considered, high earth orbits (between geostationary and lunar orbit altitudes), solar orbits (such as a 0.90 AU circular solar orbit) or a direct injection to solar system escape appear to be the best candidates. Both earth orbits and solar orbits have uncertainties regarding orbit stability and waste package integrity for times on the order of a million years.

The Ĝ infrared search for extraterrestrial civilizations with large energy supplies. I. Background and justification

International Nuclear Information System (INIS)

Wright, J. T.; Mullan, B.; Sigurdsson, S.; Povich, M. S.

2014-01-01

We motivate the Ĝ infrared search for extraterrestrial civilizations with large energy supplies. We discuss some philosophical difficulties of the search for extraterrestrial intelligence (SETI), and how communication SETI circumvents them. We review 'Dysonian SETI', the search for artifacts of alien civilizations, and find that it is highly complementary to traditional communication SETI; the two together might succeed where either one alone has not. We discuss the argument of Hart that spacefaring life in the Milky Way should be either galaxy-spanning or non-existent, and examine a portion of his argument that we call the 'monocultural fallacy'. We discuss some rebuttals to Hart that invoke sustainability and predict long Galaxy colonization timescales. We find that the maximum Galaxy colonization timescale is actually much shorter than previous work has found (<10 9 yr), and that many 'sustainability' counter-arguments to Hart's thesis suffer from the monocultural fallacy. We extend Hart's argument to alien energy supplies and argue that detectably large energy supplies can plausibly be expected to exist because life has the potential for exponential growth until checked by resources or other limitations, and intelligence implies the ability to overcome such limitations. As such, if Hart's thesis is correct, then searches for large alien civilizations in other galaxies may be fruitful; if it is incorrect, then searches for civilizations within the Milky Way are more likely to succeed than Hart argued. We review some past Dysonian SETI efforts and discuss the promise of new mid-infrared surveys, such as that of WISE.

The effects of emotion on younger and older adults' monitoring of learning.

Science.gov (United States)

Tauber, Sarah K; Dunlosky, John; Urry, Heather L; Opitz, Philipp C

2017-09-01

Age-related differences in memory monitoring appear when people learn emotional words. Namely, younger adults' judgments of learning (JOLs) are higher for positive than neutral words, whereas older adults' JOLs do not discriminate between positive versus neutral words. In two experiments, we evaluated whether this age-related difference extends to learning positive versus neutral pictures. We also evaluated the contribution of two dimensions of emotion that may impact younger and older adults' JOLs: valence and arousal. Younger and older adults studied pictures that were positive or neutral and either high or low in arousal. Participants made immediate JOLs and completed memory tests. In both experiments, the magnitude of older adults' JOLs was influenced by emotion, and both younger and older adults demonstrated an emotional salience effect on JOLs. As important, the magnitude of participants' JOLs was influenced by valence, and not arousal. Emotional salience effects were also evident on participants' free recall, and older adults recalled as many pictures as did younger adults. Taken together, these data suggest that older adults do not have a monitoring deficit when learning positive (vs. neutral) pictures and that emotional salience effects on younger and older adults' JOLs are produced more by valence than by arousal.

Scientific Conference Younger generation SNUS 2007. 3. Proceedings of the Abstracts

International Nuclear Information System (INIS)

2007-01-01

Scientific conference Younger generation SNUS 2007 was carried out on April 27, 2006 as a part of the 18 th Annual General Meeting of the Slovak Nuclear Society (SNUS). Totally, 11 persons took part in Scientific conference Younger generation SNUS 2007. Eleven scientific lectures were presented.

Measurement of cosmogenic nuclides in extraterrestrial material

International Nuclear Information System (INIS)

Nishiizumi, K.; Arnold, J.R.

1981-01-01

Meteorites are rocks and pieces of iron-nickel alloy which fall to earth from time to time. They were formed about 4.6 billion years ago when our solar system was started. Thus it has been said that meteorites are the Rosetta stones of our solar system. We use the long-lived radioactive nuclides produced by cosmic ray bombardment, to study the history of the meteorites and also the history of the cosmic rays. When we have these historical facts in our hads, we hope we will be able to understand better how the solar system works, and how it got started. We can also learn more about the nature and origin of the cosmic rays. The accelerator mass spectrometry method helps not only reduce sample size, in most cases by two or three orders of magnitude, but opens another set of cosmogenic nuclides which have not been measured yet. Already 10 Be (t/sub 1/2 = 1.6 x 10 6 y), 36 Cl (3.0 x 10 5 y) and 129 I (1.6 x 10 7 y) in meteorites have been measured by accelerator mass spectrometry [3, 4, 7, 10]. Possible new candidates for measurement in extraterrestrial materials are 26 Al (7.2 x 10 5 y), 41 Ca (1.3 x 10 5 y), 60 Fe (approx. 10 5 y) and 59 Ni (7.6 x 10 4 y). We hope also to measure 146 Sm (1.0 x 10 8 y) and 92 Nb

International law implications of the detection of extraterrestrial intelligent signals

Science.gov (United States)

Kopal, Vladimir

This paper first considers whether the present law of outer space, as it has been enshrined in five United Nations treaties and other legal documents concerning outer space, provides a satisfactory basis for SETI/CETI activities. In the author's opinion, these activities may serve "the common interest of all mankind in the progress of the exploration and use of outer space for peaceful purposes," as recognized in the 1967 Outer Space Treaty. The use of the radio frequency spectrum for SETI/CETI purposes should be in conformity with the legal principles governing this valuable natural resource, as expressed in the International Telecommunication Convention and related documents, and with allocations of the relevant segments of the spectrum by the competent bodies of the International Telecommunication Union. In the second part the author examines the impact that the detection of extraterrestrial intelligent signals may have on the present body of space law. A possible role for the United Nations in this respect is also explored and a timely interest of the world body in discussing questions relating to this subject is recommended. Consideration of these questions could become a tool helping to concentrate the attention of the world community on problems of common concern and thus to strengthen international cooperation. However, the author believes that a law-making process that would aim at elaborating a special regulation of activities in this field would be premature at this stage. It should be initiated only when the boundary between possibilities and realities is crossed. Finally, the paper outlines some likely transformation in our space law thinking that would be the consequence of the detection of extraterrestrial intelligent signals. Elaboration of the principles and norms to govern relations between the international community of our own planet and other intelligent communities in the universe would add a new dimension to the present body of outer space

Musk ox (Ovibos moschatus) of the mammoth steppe

DEFF Research Database (Denmark)

Raghavan, Maanasa; Themudo, Goncalo Espregueira Cruz; Smith, Colin

2014-01-01

Stable carbon and nitrogen isotope ratios have been used as markers for palaeoclimatic and palaeoecological reconstructions across various geographical and temporal ranges. Such studies are essential for understanding how a particular species responded to changing environmental conditions...... in precipitation and that these variations were closely associated with events such as the cold and arid Last Glacial Maximum (LGM), Bolling-Allerod interstadial, Younger Dryas stadial and the warmer and humid Holocene. Regional differences in the isotopic composition of the musk ox populations are also noticeable...

Reconstructing lake evaporation history and the isotopic composition of precipitation by a coupled δ18O-δ2H biomarker approach

Science.gov (United States)

Hepp, Johannes; Tuthorn, Mario; Zech, Roland; Mügler, Ines; Schlütz, Frank; Zech, Wolfgang; Zech, Michael

2015-10-01

Over the past decades, δ18O and δ2H analyses of lacustrine sediments became an invaluable tool in paleohydrology and paleolimnology for reconstructing the isotopic composition of past lake water and precipitation. However, based on δ18O or δ2H records alone, it can be challenging to distinguish between changes of the precipitation signal and changes caused by evaporation. Here we propose a coupled δ18O-δ2H biomarker approach that provides the possibility to disentangle between these two factors. The isotopic composition of long chain n-alkanes (n-C25, n-C27, n-C29, n-C31) were analyzed in order to establish a 16 ka Late Glacial and Holocene δ2H record for the sediment archive of Lake Panch Pokhari in High Himalaya, Nepal. The δ2Hn-alkane record generally corroborates a previously established δ18Osugar record reporting on high values characterizing the deglaciation and the Older and the Younger Dryas, and low values characterizing the Bølling and the Allerød periods. Since the investigated n-alkane and sugar biomarkers are considered to be primarily of aquatic origin, they were used to reconstruct the isotopic composition of lake water. The reconstructed deuterium excess of lake water ranges from +57‰ to -85‰ and is shown to serve as proxy for the evaporation history of Lake Panch Pokhari. Lake desiccation during the deglaciation, the Older Dryas and the Younger Dryas is affirmed by a multi-proxy approach using the Hydrogen Index (HI) and the carbon to nitrogen ratio (C/N) as additional proxies for lake sediment organic matter mineralization. Furthermore, the coupled δ18O and δ2H approach allows disentangling the lake water isotopic enrichment from variations of the isotopic composition of precipitation. The reconstructed 16 ka δ18Oprecipitation record of Lake Panch Pokhari is well in agreement with the δ18O records of Chinese speleothems and presumably reflects the Indian Summer Monsoon variability.

Vaccination Patterns in Children After Autism Spectrum Disorder Diagnosis and in Their Younger Siblings.

Science.gov (United States)

Zerbo, Ousseny; Modaressi, Sharareh; Goddard, Kristin; Lewis, Edwin; Fireman, Bruce H; Daley, Matthew F; Irving, Stephanie A; Jackson, Lisa A; Donahue, James G; Qian, Lei; Getahun, Darios; DeStefano, Frank; McNeil, Michael M; Klein, Nicola P

2018-05-01

In recent years, rates of vaccination have been declining. Whether this phenomenon disproportionately affects children with autism spectrum disorder (ASD) or their younger siblings is unknown. To investigate if children after receiving an ASD diagnosis obtain their remaining scheduled vaccines according to the Advisory Committee on Immunization Practices (ACIP) recommendations and to compare the vaccination patterns of younger siblings of children with ASD with the vaccination patterns of younger siblings of children without ASD. This investigation was a retrospective matched cohort study. The setting was 6 integrated health care delivery systems across the United States within the Vaccine Safety Datalink. Participants were children born between January 1, 1995, and September 30, 2010, and their younger siblings born between January 1, 1997, and September 30, 2014. The end of follow-up was September 30, 2015. Recommended childhood vaccines between ages 1 month and 12 years. The proportion of children who received all of their vaccine doses according to ACIP recommendations. The study included 3729 children with ASD (676 [18.1%] female), 592 907 children without ASD, and their respective younger siblings. Among children without ASD, 250 193 (42.2%) were female. For vaccines recommended between ages 4 and 6 years, children with ASD were significantly less likely to be fully vaccinated compared with children without ASD (adjusted rate ratio, 0.87; 95% CI, 0.85-0.88). Within each age category, vaccination rates were significantly lower among younger siblings of children with ASD compared with younger siblings of children without ASD. The adjusted rate ratios varied from 0.86 for siblings younger than 1 year to 0.96 for those 11 to 12 years old. Parents who had a child with ASD were more likely to refuse at least 1 recommended vaccine for that child's younger sibling and to limit the number of vaccines administered during the younger sibling's first year of life

New Fiber Reinforced Waterless Concrete for Extraterrestrial Structural Applications

Science.gov (United States)

Toutanji, H.; Tucker, D.; Ethridge, E.

2005-01-01

Commercial use of sulfur concrete on Earth is well established, particularly in corrosive, e.g., acid and salt, environments. Having found troilite (FeS) on the Moon raises the question of using extracted sulfur as a lunar construction mate: iii an attractive alternative to conventional concrete as it does not require water For the purpose of this paper it is assumed that lunar ore is mined, refined, and the raw sulfur processed with appropriate lunar regolith to form, for example, brick and beam elements. Glass fibers produced from regolith were used as a reinforcement to improve the mechanical properties of the sulfur concrete. Glass fibers and glass rebar were produced by melting the lunar regolith simulant. Lunar regolith stimulant was melted in a 25 cc Pt-Rh crucible in a Sybron Thermoline 46100 high temperature MoSi2 furnace at melting temperatures of 1450 to 1600G. The glass melt wets the ceramic rod and long continuous glass fibers were easily hand drawn. The glass fibers were immediately coated with a protective polymer to maintain the mechanical strength. The viability of sulfur concrete as a construction material for extraterrestrial application is presented. The mechanical properties of the glass fiber reinforced sulfur concrete were investigated.

Both Younger and Older Adults Have Difficulty Updating Emotional Memories

OpenAIRE

Nashiro, Kaoru; Sakaki, Michiko; Huffman, Derek; Mather, Mara

2012-01-01

Objective. The main purpose of the study was to examine whether emotion impairs associative memory for previously seen items in older adults, as previously observed in younger adults. \\ud Method. Thirty-two younger adults and 32 older adults participated. The experiment consisted of 2 parts. In Part 1, participants learned picture–object associations for negative and neutral pictures. In Part 2, they learned picture–location associations for negative and neutral pictures; half of these pictur...

Application of Alkenone 14C-Based chronostratigraphy in carbonate barren sediments on the Peru Margin.

Science.gov (United States)

Higginson, M. J.; Altabet, M. A.; Herbert, T. D.

2003-04-01

the timing of the Younger Dryas. We presume that the enlarged SST amplitude of these sites comes from the sensitivity of the Peru margin to the dominant upwelling signal and its proximity to the Andes, from which there is evidence for a Younger Dryas response. The appearance of a Bolling-Allerod/Younger Dryas SST reversal consistent with published dates is further verification of our chronostratigraphic methods.

Time constraints for post-LGM landscape response to deglaciation in Val Viola, Central Italian Alps

Science.gov (United States)

Scotti, Riccardo; Brardinoni, Francesco; Crosta, Giovanni Battista; Cola, Giuseppe; Mair, Volkmar

2017-12-01

Across the northern European Alps, a long tradition of Quaternary studies has constrained post-LGM (Last Glacial Maximum) landscape history. The same picture remains largely unknown for the southern portion of the orogen. In this work, starting from existing 10Be exposure dating of three boulders in Val Viola, Central Italian Alps, we present the first detailed, post-LGM reconstruction of landscape (i.e., glacial, periglacial and paraglacial) response south of the Alpine divide. We pursue this task through Schmidt-hammer exposure-age dating (SHD) at 34 sites including moraines, rock glaciers, protalus ramparts, rock avalanche deposits and talus cones. In addition, based on the mapping of preserved moraines and on the numerical SHD ages, we reconstruct the glacier extent of four different stadials, including Egesen I (13.1 ± 1.1 ka), Egesen II (12.3 ± 0.6 ka), Kartell (11.0 ± 1.4 ka) and Kromer (9.7 ± 1.4 ka), whose chronologies agree with available counterparts from north of the Alpine divide. Results show that Equilibrium Line Altitude depressions (ΔELAs) associated to Younger Dryas and Early Holocene stadials are smaller than documented at most available sites in the northern Alps. These findings not only support the hypothesis of a dominant north westerly atmospheric circulation during the Younger Dryas, but also suggest that this pattern could have lasted until the Early Holocene. SHD ages on rock glaciers and protalus ramparts indicate that favourable conditions to periglacial landform development occurred during the Younger Dryas (12.7 ± 1.1 ka), on the valley slopes above the glacier, as well as in newly de-glaciated areas, during the Early Holocene (10.7 ± 1.3 and 8.8 ± 1.8 ka). The currently active rock glacier started to develop before 3.7 ± 0.8 ka and can be associated to the Löbben oscillation. Four of the five rock avalanches dated in Val Viola cluster within the Early Holocene, in correspondence of an atmospheric warming phase. By contrast

Timing of last deglaciation in the Cantabrian Mountains (Iberian Peninsula; North Atlantic Region) based on in situ-produced 10Be exposure dating

Science.gov (United States)

Rodríguez-Rodríguez, Laura; Jiménez-Sánchez, Montserrat; Domínguez-Cuesta, María José; Rinterknecht, Vincent; Pallàs, Raimon; Aumaître, Georges; Bourlès, Didier L.; Keddadouche, Karim; Aster Team

2017-09-01

The Last Glacial Termination led to major changes in ice sheet coverage that disrupted global patterns of atmosphere and ocean circulation. Paleoclimate records from Iberia suggest that westerly episodes played a key role in driving heterogeneous climate in the North Atlantic Region. We used 10Be Cosmic Ray Exposure (CRE) dating to explore the glacier response of small mountain glaciers (ca. 5 km2) that developed on the northern slope of the Cantabrian Mountains (Iberian Peninsula), an area directly under the influence of the Atlantic westerly winds. We analyzed twenty boulders from three moraines and one rock glacier arranged as a recessional sequence preserved between 1150 and 1540 m above sea level (a.s.l.) in the Monasterio valley (Redes Natural Park). Results complement previous chronologic data based on radiocarbon and optically stimulated luminescence from the Monasterio valley, which suggest a local Glacial Maximum (local GM) prior to 33 ka BP and a long-standing glacier advance at 24 ka coeval to the global Last Glacial Maximum (LGM). Resultant 10Be CRE ages suggest a progressive retreat and thinning of the Monasterio glacier over the time interval 18.1-16.7 ka. This response is coeval with the Heinrich Stadial 1, an extremely cold and dry climate episode initiated by a weakening of the Atlantic Meridional Overturning Circulation (AMOC). Glacier recession continued through the Bølling/Allerød period as indicate the minimum exposure ages obtained from a cirque moraine and a rock glacier nested within this moraine, which yielded ages of 14.0 and 13.0 ka, respectively. Together, they suggest that the Monasterio glacier experienced a gradual transition from glacier to rock glacier activity as the AMOC started to strengthen again. Glacial evidence ascribable to the Younger Dryas cooling was not dated in the Monasterio valley, but might have occurred at higher elevations than evidence dated in this work. The evolution of former glaciers documented in the

Astrobiology in culture: the search for extraterrestrial life as "science".

Science.gov (United States)

Billings, Linda

2012-10-01

This analysis examines the social construction of authority, credibility, and legitimacy for exobiology/astrobiology and, in comparison, the search for extraterrestrial intelligence (SETI), considering English-language conceptions of these endeavors in scientific culture and popular culture primarily in the United States. The questions that define astrobiology as a scientific endeavor are multidisciplinary in nature, and this endeavor is broadly appealing to public audiences as well as to the scientific community. Thus, it is useful to examine astrobiology in culture-in scientific culture, official culture, and popular culture. A researcher may explore science in culture, science as culture, by analyzing its rhetoric, the primary means that people use to construct their social realities-their cultural environment, as it were. This analysis follows this path, considering scientific and public interest in astrobiology and SETI and focusing on scientific and official constructions of the two endeavors. This analysis will also consider whether and how scientific and public conceptions of astrobiology and SETI, which are related but at the same time separate endeavors, converge or diverge and whether and how these convergences or divergences affect the scientific authority, credibility, and legitimacy of these endeavors.

Detection of /sup 4/He in stratospheric particles gives evidence of extraterrestrial origin

Energy Technology Data Exchange (ETDEWEB)

Rajan, R S [Carnegie Institution of Washington, D.C. (USA). Dept. of Terrestrial Magnetism; Brownlee, D E; Tomandl, D; Hodge, P W; Farrar, H; Britten, R A

1977-05-12

The detection of large concentrations of /sup 4/He in some ..mu..m size stratospheric particles collected during the past 2 years is here reported. The final /sup 4/He concentrations ranged from 0.002 to 0.25 cc/gm. Such high concentrations confirm that the particles were extraterrestrial and that some of them were exposed to solar wind for at least 10 to 100 years; also, since solar wind ions are implanted only to depths of approximately 500 A, the measurements also indicate that the particles existed as small particles in space and were not produced in the atmosphere by fragmentation of larger meteoroids. The possibility that the observed He could have been the product of decaying U appears remote. Since micrometeorites probably have cometary origin, they are potentially a valuable source of primitive Solar System matter.

Destination memory in social interaction: better memory for older than for younger destinations in normal aging?

Science.gov (United States)

El Haj, Mohamad; Raffard, Stéphane; Fasotti, Luciano; Allain, Philippe

2018-05-01

Destination memory, a memory component allowing the attribution of information to its appropriate receiver (e.g., to whom did I lend my pen?), is compromised in normal aging. The present paper investigated whether older adults might show better memory for older destinations than for younger destinations. This hypothesis is based on empirical research showing better memory for older faces than for younger faces in older adults. Forty-one older adults and 44 younger adults were asked to tell proverbs to older and younger destinations (i.e., coloured faces). On a later recognition test, participants had to decide whether they had previously told some proverb to an older/younger destination or not. Prior to this task, participants reported their frequency of contact with other-age groups. The results showed lower destination memory in older adults than in younger adults. Interestingly, older adults displayed better memory for older than for younger destinations. The opposite pattern was seen in younger adults. The low memory for younger destinations, as observed in older adults, was significantly correlated with limited exposure to younger individuals. These findings suggest that for older adults, the social experience can play a crucial role in the destination memory, at least as far as exposure to other-age groups is concerned.

Exploring sibling attitudes towards participation when the younger ...

African Journals Online (AJOL)

Data from a study involving parents of preschool children who were receiving ... Typically developing children who have a younger sibling with a disability often feel inadequately supported and excluded ..... from pressure where children.

The Preboreal oscillation around the Nordic Seas: terrestrial and lacustrine responses

DEFF Research Database (Denmark)

Börck, Svante; Rundgren, Mats; Ingolfsson, Olafur

1997-01-01

Europe. This is documented by vegetation changes, decreased aquatic production, increased soil erosion, increased 2H and 13C content in tree-rings, readvances or stillstands of the ice sheet in Norway and Finland, and ingression of brackish water into the Baltic. Icelandic proxy records from lake...... sediments and glacial moraines imply cooler conditions than during the previous Preboreal period, but not as extreme as during the Younger Dryas. Greenland records suggest that the early Preboreal was characterised by ice readvances, as an effect of cool climate and increased precipitation (in relation...

High-resolution Greenland Ice Core data show abrupt climate change happens in few years

DEFF Research Database (Denmark)

Steffensen, Jørgen Peder; Andersen, Katrine Krogh; Bigler, Matthias

2008-01-01

The last two abrupt warmings at the onset of our present warm interglacial period, interrupted by the Younger Dryas cooling event, were investigated at high temporal resolution from the North Greenland Ice Core Project ice core. The deuterium excess, a proxy of Greenland precipitation moisture...... source, switched mode within 1 to 3 years over these transitions and initiated a more gradual change (over 50 years) of the Greenland air temperature, as recorded by stable water isotopes. The onsets of both abrupt Greenland warmings were slightly preceded by decreasing Greenland dust deposition...

Intelligibility of emotional speech in younger and older adults.

Science.gov (United States)

Dupuis, Kate; Pichora-Fuller, M Kathleen

2014-01-01

Little is known about the influence of vocal emotions on speech understanding. Word recognition accuracy for stimuli spoken to portray seven emotions (anger, disgust, fear, sadness, neutral, happiness, and pleasant surprise) was tested in younger and older listeners. Emotions were presented in either mixed (heterogeneous emotions mixed in a list) or blocked (homogeneous emotion blocked in a list) conditions. Three main hypotheses were tested. First, vocal emotion affects word recognition accuracy; specifically, portrayals of fear enhance word recognition accuracy because listeners orient to threatening information and/or distinctive acoustical cues such as high pitch mean and variation. Second, older listeners recognize words less accurately than younger listeners, but the effects of different emotions on intelligibility are similar across age groups. Third, blocking emotions in list results in better word recognition accuracy, especially for older listeners, and reduces the effect of emotion on intelligibility because as listeners develop expectations about vocal emotion, the allocation of processing resources can shift from emotional to lexical processing. Emotion was the within-subjects variable: all participants heard speech stimuli consisting of a carrier phrase followed by a target word spoken by either a younger or an older talker, with an equal number of stimuli portraying each of seven vocal emotions. The speech was presented in multi-talker babble at signal to noise ratios adjusted for each talker and each listener age group. Listener age (younger, older), condition (mixed, blocked), and talker (younger, older) were the main between-subjects variables. Fifty-six students (Mage= 18.3 years) were recruited from an undergraduate psychology course; 56 older adults (Mage= 72.3 years) were recruited from a volunteer pool. All participants had clinically normal pure-tone audiometric thresholds at frequencies ≤3000 Hz. There were significant main effects of

Curating NASA's future extraterrestrial sample collections: How do we achieve maximum proficiency?

Science.gov (United States)

McCubbin, Francis; Evans, Cynthia; Allton, Judith; Fries, Marc; Righter, Kevin; Zolensky, Michael; Zeigler, Ryan

2016-07-01

Introduction: The Astromaterials Acquisition and Curation Office (henceforth referred to herein as NASA Curation Office) at NASA Johnson Space Center (JSC) is responsible for curating all of NASA's extraterrestrial samples. Under the governing document, NASA Policy Directive (NPD) 7100.10E "Curation of Extraterrestrial Materials", JSC is charged with "The curation of all extraterrestrial material under NASA control, including future NASA missions." The Directive goes on to define Curation as including "…documentation, preservation, preparation, and distribution of samples for research, education, and public outreach." Here we describe some of the ongoing efforts to ensure that the future activities of the NASA Curation Office are working to-wards a state of maximum proficiency. Founding Principle: Curatorial activities began at JSC (Manned Spacecraft Center before 1973) as soon as design and construction planning for the Lunar Receiving Laboratory (LRL) began in 1964 [1], not with the return of the Apollo samples in 1969, nor with the completion of the LRL in 1967. This practice has since proven that curation begins as soon as a sample return mission is conceived, and this founding principle continues to return dividends today [e.g., 2]. The Next Decade: Part of the curation process is planning for the future, and we refer to these planning efforts as "advanced curation" [3]. Advanced Curation is tasked with developing procedures, technology, and data sets necessary for curating new types of collections as envisioned by NASA exploration goals. We are (and have been) planning for future curation, including cold curation, extended curation of ices and volatiles, curation of samples with special chemical considerations such as perchlorate-rich samples, curation of organically- and biologically-sensitive samples, and the use of minimally invasive analytical techniques (e.g., micro-CT, [4]) to characterize samples. These efforts will be useful for Mars Sample Return

The experience of demanding work environments in younger workers.

Science.gov (United States)

Winding, T N; Labriola, M; Nohr, E A; Andersen, J H

2015-06-01

Investigating whether certain individual or background characteristics are associated with an increased risk of experiencing an excessively demanding work environment in younger workers may help to reduce future inequality in health and maximize their labour market participation. To describe the work environment of Danish 20- to 21-year olds and to investigate the influence of family socioeconomic background and individual characteristics at age 14-15 on later experience of physical and psychosocial work environments. We obtained information on subjects' school performance, vulnerability, health and parental socioeconomic status from registers and a questionnaire completed in 2004. A questionnaire concerning eight measures of subjects' psychosocial and physical work environment in 2010 was used to determine the outcomes of interest. The study population consisted of 679 younger workers aged 20-21. The psychosocial work environment was in general good but younger workers experienced more demanding physical work than the general working population. Overall, individual as well as family factors had a limited impact on their assessment of the work environment. Low self-esteem at age 14-15 was associated with experiencing high demands and lack of trust and fairness at work, whereas low parental socioeconomic status was associated with a demanding physical work environment. This study showed a social gradient in experiencing a demanding physical work environment at age 20-21. The psychosocial work environment experienced by younger workers was generally good, but vulnerable young people may need special attention to protect them from or prepare them for psychosocially demanding jobs later in life. © The Author 2015. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Hippocampal sclerosis in children younger than 2 years

Energy Technology Data Exchange (ETDEWEB)

Kadom, Nadja [Children' s National Medical Center, Department of Diagnostic Imaging and Radiology, Washington, DC (United States); Tsuchida, Tammy; Gaillard, William D. [Children' s National Medical Center, Department of Neurology, Washington, DC (United States)

2011-10-15

Hippocampal sclerosis (HS) is rarely considered as a diagnosis in children younger than 2 years. To describe imaging features in conjunction with clinical information in patients with hippocampal sclerosis who are younger than 2 years. We retrospectively reviewed MR brain imaging and clinical information in five children in whom the diagnosis of HS was made both clinically and by MRI prior to 2 years of age. Imaging features establishing the diagnosis of hippocampal sclerosis were bright T2 signal and volume loss, while the internal architecture of the hippocampal formation was preserved in almost all children. Clinically, all children had an infectious trigger. It is necessary for radiologists to consider HS in children with certain clinical features to plan an MRI protocol that is appropriate for detection of hippocampal pathology. (orig.)

Hippocampal sclerosis in children younger than 2 years

International Nuclear Information System (INIS)

Kadom, Nadja; Tsuchida, Tammy; Gaillard, William D.

2011-01-01

Hippocampal sclerosis (HS) is rarely considered as a diagnosis in children younger than 2 years. To describe imaging features in conjunction with clinical information in patients with hippocampal sclerosis who are younger than 2 years. We retrospectively reviewed MR brain imaging and clinical information in five children in whom the diagnosis of HS was made both clinically and by MRI prior to 2 years of age. Imaging features establishing the diagnosis of hippocampal sclerosis were bright T2 signal and volume loss, while the internal architecture of the hippocampal formation was preserved in almost all children. Clinically, all children had an infectious trigger. It is necessary for radiologists to consider HS in children with certain clinical features to plan an MRI protocol that is appropriate for detection of hippocampal pathology. (orig.)

Both younger and older adults have difficulty updating emotional memories.

Science.gov (United States)

Nashiro, Kaoru; Sakaki, Michiko; Huffman, Derek; Mather, Mara

2013-03-01

The main purpose of the study was to examine whether emotion impairs associative memory for previously seen items in older adults, as previously observed in younger adults. Thirty-two younger adults and 32 older adults participated. The experiment consisted of 2 parts. In Part 1, participants learned picture-object associations for negative and neutral pictures. In Part 2, they learned picture-location associations for negative and neutral pictures; half of these pictures were seen in Part 1 whereas the other half were new. The dependent measure was how many locations of negative versus neutral items in the new versus old categories participants remembered in Part 2. Both groups had more difficulty learning the locations of old negative pictures than of new negative pictures. However, this pattern was not observed for neutral items. Despite the fact that older adults showed overall decline in associative memory, the impairing effect of emotion on updating associative memory was similar between younger and older adults.

Infliximab therapy in pediatric patients 7 years of age and younger.

Science.gov (United States)

Kelsen, Judith R; Grossman, Andrew B; Pauly-Hubbard, Helen; Gupta, Kernika; Baldassano, Robert N; Mamula, Petar

2014-12-01

Infliximab (IFX) is efficacious for induction and maintenance of remission in pediatric patients with moderate-to-severe inflammatory bowel disease (IBD). It has, however, not been studied in patients 7 years old and younger. Our aim was to characterize efficacy and safety of IFX therapy in this cohort. This was a retrospective study of patients with IBD ages 7 years and younger, treated with IFX between 1999 and 2011. Medical records were reviewed for age of diagnosis, disease phenotype, therapy, surgery, IFX infusion dates, dose, and intervals. Outcome measures included physician global assessment, corticosteroid requirement, and adverse events. Thirty-three children (ages 2.4-7 years) were included. Twenty patients had Crohn disease, 4 had ulcerative colitis, and 9 had indeterminate colitis. Maintenance of IFX therapy at 1, 2, and 3 years was 36%, 18%, and 12%, respectively. Patients of age 5 years and younger had the lowest rates of maintenance of therapy at 25% at year 1, and 10% at years 2 and 3 combined. Nine percent of all of the patients demonstrated response measured by the physician global assessment and were steroid free at 1 year. There were 8 infusion reactions. There were no malignancies, serious infections, or deaths. IFX demonstrated a modest response rate and a low steroid-sparing effect in patients with IBD 7 years old and younger. Although this is a limited study, there appears to be a trend for decreased sustained efficacy with IFX in this age group, particularly in children 5 years old and younger, when compared with the previously published literature in older children.

Lung cancer in patients younger than 40 years in a multiracial Asian country.

Science.gov (United States)

Liam, C K; Lim, K H; Wong, C M

2000-12-01

This study aimed to determine whether the clinicopathological features of lung cancer in patients younger than 40 years differ from that of older patients in an Asian country. We undertook a review of the clinicopathological data of all patients with confirmed primary lung cancer at the Department of Medicine, University of Malaya Medical Centre, Kuala Lumpur, Malaysia, from October 1991 to September 1999. Of the 580 patients with lung cancer, 36 (6.2%; 23 males, 13 females) were 21-39 years old at diagnosis. The percentage of people who had never smoked was higher among the younger patients (58.3% vs 19.1%, P < 0.001). Although adenocarcinoma was the most common cell type in both groups, its incidence was higher in the younger patients (24/36 (66.7%) vs 228/544 (41.9%), P = 0.007). The mean World Health Organization performance status at presentation was worse in the younger patients (2.4 vs 2, P = 0.007). In the case of non-small cell lung cancer, all the younger patients presented with either stage IIIb or metastatic disease compared to 77.2% of the older patients (P < 0.001). Younger lung cancer patients were more likely than older patients to have never smoked, to have adenocarcinoma, and to present with poorer performance status and with more advanced-stage non-small cell lung cancer.

[Characteristics of emergency poisoning cases in elderly versus younger patients].

Science.gov (United States)

Supervía Caparrós, August; Pallàs Villaronga, Oriol; Clemente Rodríguez, Carlos; Aranda Cárdenas, María Dolores; Pi-Figueras Valls, María; Cirera Lorenzo, Isabel

2017-10-01

To compare cases of poisoning according to age to detect differences in frequency of visits to the emergency department, patient characteristics, case management, and immediate outcome in terms of related mortality. Descriptive study of a retrospective series of patients who visited a university hospital emergency department for treatment of poisoning between 2009 and 2014. We collected patient characteristics and data related to the event, case management, and poisoning-related death. Patients were grouped according to age (cut-off 65 y). Of a total of 3847 poisoning episodes, 341 (8.9%) were in patients aged 65 years or older. The percentage of women among these older patients (61.3%) was greater than among younger patients (36.3%; P<.001). Poisoning was accidental in older patients more often than younger ones (64.4% vs 9.5%, respectively; P<.001), occurred more often in the home (82.1% vs 37%, P<.001), and more often required active treatment (73.3% vs 57.4%; P<.001) and admission to hospital (21.4% vs 7.3%, P<.001). The related mortality rate was also higher in the older patients (2.1% vs 0.1% in younger patients, P<.001). The percentage of poisonings in patients aged 65 years or older is not negligible. Poisoning in patients of advanced age tends to be accidental and take place in the home. Older patients more often require active treatment and hospital admission; poisoning-related death is more common in older patients than younger ones.

Understanding the effect of workload on automation use for younger and older adults.

Science.gov (United States)

McBride, Sara E; Rogers, Wendy A; Fisk, Arthur D

2011-12-01

This study examined how individuals, younger and older, interacted with an imperfect automated system. The impact of workload on performance and automation use was also investigated. Automation is used in situations characterized by varying levels of workload. As automated systems spread to domains such as transportation and the home, a diverse population of users will interact with automation. Research is needed to understand how different segments of the population use automation. Workload was systematically manipulated to create three levels (low, moderate, high) in a dual-task scenario in which participants interacted with a 70% reliable automated aid. Two experiments were conducted to assess automation use for younger and older adults. Both younger and older adults relied on the automation more than they complied with it. Among younger adults, high workload led to poorer performance and higher compliance, even when that compliance was detrimental. Older adults' performance was negatively affected by workload, but their compliance and reliance were unaffected. Younger and older adults were both able to use and double-check an imperfect automated system. Workload affected how younger adults complied with automation, particularly with regard to detecting automation false alarms. Older adults tended to comply and rely at fairly high rates overall, and this did not change with increased workload. Training programs for imperfect automated systems should vary workload and provide feedback about error types, and strategies for identifying errors. The ability to identify automation errors varies across individuals, thereby necessitating training.

Reducing the framing effect in older and younger adults by encouraging analytic processing.

Science.gov (United States)

Thomas, Ayanna K; Millar, Peter R

2012-03-01

The present study explored whether the framing effect could be reduced in older and younger adults using techniques that influenced the accessibility of information relevant to the decision-making processing. Accessibility was manipulated indirectly in Experiment 1 by having participants engage in concurrent tasks, and directly in Experiment 2, through an instructions manipulation that required participants to maintain a goal of analytic processing throughout the experimental trial. We tested 120 older and 120 younger adults in Experiment 1. Participants completed 28 decision trials while concurrently either performing a probability calculation task or a memory task. In Experiment 2, we tested 136 older and 136 younger adults. Participants completed 48 decision trials after either having been instructed to "think like a scientist" or base decisions on "gut reactions." Results demonstrated that the framing effect was reduced in older and younger adults in the probability calculation task in Experiment 1 and under the "think like a scientist" instructions manipulation in Experiment 2. These results suggest that when information relevant to unbiased decision making was made more accessible, both older and younger adults were able to reduce susceptibility to the framing effect.

Evaluation of a workplace engagement project for people with younger onset dementia.

Science.gov (United States)

Robertson, Jacinta; Evans, David

2015-08-01

In 2011, a workplace project was established to provide a small group of people who had younger onset dementia with the opportunity to return to the workplace. The project sought to explore the feasibility and safety of engaging these younger people in workplace activities if an appropriate framework of support was provided. Opportunities to engage in meaningful activities are quite limited for younger people with dementia because services are targeted at an older client population. A qualitative exploratory approach was used for the project evaluation. Participants were people who were 65 years or younger and had a diagnosis of dementia. They attended a large metropolitan hardware store one day per week and worked beside a store employee for a four hour work shift. Evaluation of the project included observation of participant's engagement in the workplace, adverse events and a qualitative analysis that used participant-nominated good project outcomes. Nine people with a mean age of 58·8 years participated in the project. Six of these participants have been engaged at the workplace for more than two years. All participants were able to gain the skills needed to complete their respective work duties. Participants initially assisted with simple work tasks, but over time, they were able to expand their range of duties to include more complex activities such as customer sales. Participants achieved their nominated good outcomes of improved well-being, engaging in worthwhile activities, contributing to society and socialisation. The evaluation has shown that this workplace programme is a viable model of engagement for younger people with dementia. This evaluation offers a practical demonstration that it is feasible and safe to provide opportunities for younger people with dementia to engage in meaningful activities in the community if appropriate support is provided. © 2015 John Wiley & Sons Ltd.

Appendicitis in Children: Evaluation of the Pediatric Appendicitis Score in Younger and Older Children

Directory of Open Access Journals (Sweden)

Martin Salö

2014-01-01

Full Text Available Background. This study aimed to evaluate Pediatric Appendicitis Score (PAS, diagnostic delay, and factors responsible for possible late diagnosis in children <4 years compared with older children who were operated on for suspected appendicitis. Method. 122 children, between 1 and 14 years, operated on with appendectomy for suspected appendicitis, were retrospectively analyzed. The cohort was divided into two age groups: ≥4 years (n=102 and <4 years (n=20. Results. The mean PAS was lower among the younger compared with the older patients (5.3 and 6.6, resp.; P=0.005, despite the fact that younger children had more severe appendicitis (75.0% and 33.3%, resp.; P=0.001. PAS had low sensitivity in both groups, with a significantly lower sensitivity among the younger patients. Parent and doctor delay were confirmed in children <4 years of age with appendicitis. PAS did not aid in patients with doctor delay. Parameters in patient history, symptoms, and abdominal examination were more diffuse in younger children. Conclusion. PAS should be used with caution when examining children younger than 4 years of age. Diffuse symptoms in younger children with acute appendicitis lead to delay and to later diagnosis and more complicated appendicitis.

On the Search for the Amino Acids on the Lunar Surface as it Relates to Other Extraterrestrial Bodies

Science.gov (United States)

Hoover, Richard B.; Kolb, Vera M.

2009-01-01

The early search for the amino acids on the lunar surface fines indicated such a low amount of the amino acids that it was deemed insignifi cant. While the later studies seemed to depart in some ways from the earlier results, they were not pursued. In this paper we critically ev aluate the results from the Apollo missions from the new perspective with considerations of the sensitivity of the instrumentation availabl e at the time. We discuss the possible relevance of the lunar results to the findings of the amino acids on the surfaces of other extraterrestrial bodies, such as Mars.

Modeling an Optical and Infrared Search for Extraterrestrial Intelligence Survey with Exoplanet Direct Imaging

Science.gov (United States)

Vides, Christina; Macintosh, Bruce; Ruffio, Jean-Baptiste; Nielsen, Eric; Povich, Matthew Samuel

2018-01-01

Gemini Planet Imager (GPI) is a direct high contrast imaging instrument coupled to the Gemini South Telescope. Its purpose is to image extrasolar planets around young (~Intelligence), we modeled GPI’s capabilities to detect an extraterrestrial continuous wave (CW) laser broadcasted within the H-band have been modeled. By using sensitivity evaluated for actual GPI observations of young target stars, we produced models of the CW laser power as a function of distance from the star that could be detected if GPI were to observe nearby (~ 3-5 pc) planet-hosting G-type stars. We took a variety of transmitters into consideration in producing these modeled values. GPI is known to be sensitive to both pulsed and CW coherent electromagnetic radiation. The results were compared to similar studies and it was found that these values are competitive to other optical and infrared observations.

Memory-guided force control in healthy younger and older adults.

Science.gov (United States)

Neely, Kristina A; Samimy, Shaadee; Blouch, Samantha L; Wang, Peiyuan; Chennavasin, Amanda; Diaz, Michele T; Dennis, Nancy A

2017-08-01

Successful performance of a memory-guided motor task requires participants to store and then recall an accurate representation of the motor goal. Further, participants must monitor motor output to make adjustments in the absence of visual feedback. The goal of this study was to examine memory-guided grip force in healthy younger and older adults and compare it to performance on behavioral tasks of working memory. Previous work demonstrates that healthy adults decrease force output as a function of time when visual feedback is not available. We hypothesized that older adults would decrease force output at a faster rate than younger adults, due to age-related deficits in working memory. Two groups of participants, younger adults (YA: N = 32, mean age 21.5 years) and older adults (OA: N = 33, mean age 69.3 years), completed four 20-s trials of isometric force with their index finger and thumb, equal to 25% of their maximum voluntary contraction. In the full-vision condition, visual feedback was available for the duration of the trial. In the no vision condition, visual feedback was removed for the last 12 s of each trial. Participants were asked to maintain constant force output in the absence of visual feedback. Participants also completed tasks of word recall and recognition and visuospatial working memory. Counter to our predictions, when visual feedback was removed, younger adults decreased force at a faster rate compared to older adults and the rate of decay was not associated with behavioral performance on tests of working memory.

Understanding the Effect of Workload on Automation Use for Younger and Older Adults

Science.gov (United States)

McBride, Sara E.; Rogers, Wendy A.; Fisk, Arthur D.

2018-01-01

Objective This study examined how individuals, younger and older, interacted with an imperfect automated system. The impact of workload on performance and automation use was also investigated. Background Automation is used in situations characterized by varying levels of workload. As automated systems spread to domains such as transportation and the home, a diverse population of users will interact with automation. Research is needed to understand how different segments of the population use automation. Method Workload was systematically manipulated to create three levels (low, moderate, high) in a dual-task scenario in which participants interacted with a 70% reliable automated aid. Two experiments were conducted to assess automation use for younger and older adults. Results Both younger and older adults relied on the automation more than they complied with it. Among younger adults, high workload led to poorer performance and higher compliance, even when that compliance was detrimental. Older adults’ performance was negatively affected by workload, but their compliance and reliance were unaffected. Conclusion Younger and older adults were both able to use and double-check an imperfect automated system. Workload affected how younger adults complied with automation, particularly with regard to detecting automation false alarms. Older adults tended to comply and rely at fairly high rates overall, and this did not change with increased workload. Application Training programs for imperfect automated systems should vary workload and provide feedback about error types, and strategies for identifying errors. The ability to identify automation errors varies across individuals, thereby necessitating training. PMID:22235529

Teen responses when a younger school-age sibling has been bullied

Science.gov (United States)

Honig, Alice Sterling; Zdunowski-Sjoblom, Nicole

2015-01-01

The prevalence of bullying among children, and the sometimes tragic consequences as a result, has become a major concern in schools. The larger research for this study reported on in-depth interviews with 28 elementary and middle school-age boys and girls (7–12 years) who had experienced various forms of bullying and relational aggression by their peers, mostly on school grounds, and the responses of their parents and teachers. Responses of the children's teen siblings to the younger child's revelations of being bullied are the focus of this report. In-depth interviews with each teen sibling (n = 28) and with each bullied child revealed how the children viewed the teen siblings' supportive strategies. Almost all the children (89%) reported that their older siblings talked with them and offered advice. The teen siblings shared with the younger ones that they too (71%) had been bullied, or they knew someone who had been bullied (18%). Teens gave the advice to ‘bully back’ to 11% and advice to ‘tell someone’ to 32% of the younger children. The children felt quite positive about their older siblings' advice (89%), which did differ depending on the bullied child's gender. Teen siblings gave advice to ‘avoid bullies’ to 77% of female and to 27% of male younger children. PMID:25931644

A double dissociation of implicit and explicit memory in younger and older adults.

Science.gov (United States)

Gopie, Nigel; Craik, Fergus I M; Hasher, Lynn

2011-05-01

This study examined whether age-related differences in cognition influence later memory for irrelevant, or distracting, information. In Experiments 1 and 2, older adults had greater implicit memory for irrelevant information than younger adults did. When explicit memory was assessed, however, the pattern of results reversed: Younger adults performed better than older adults on an explicit memory test for the previously irrelevant information, and older adults performed less well than they had on the implicit test. Experiment 3 investigated whether this differential pattern was attributable to an age-related decline in encoding resources, by reducing the encoding resources of younger adults with a secondary task; their performance perfectly simulated the pattern shown by the older adults in the first two experiments. Both older and younger adults may remember irrelevant information, but they remember it in different ways because of age-related changes in how information is processed at encoding and utilized at retrieval.

Walking through doorways causes forgetting: Younger and older adults.

Science.gov (United States)

Radvansky, Gabriel A; Pettijohn, Kyle A; Kim, Joonsung

2015-06-01

Previous research on event cognition has found that walking through doorways can cause forgetting. The explanation for this finding is that there is a competition between event models, producing interference, and depressing performance. The current study explored the degree to which this might be affected by the natural aging process. This is of interest because there is some evidence that older adults have trouble coordinating sources of interference, which is what is thought to underlie this effect. This would suggest that older adults should do worse on this task. Alternatively, there is also evidence that older adults are typically not disrupted at the event level of processing per se. This would suggest that older adults should perform similarly to younger adults on this task. In the study reported here, younger and older participants navigated through a virtual environment, and memory was tested with probes either before or after a shift and for objects that were associated with the participant (i.e., just picked up). In general, both younger and older adults had memory disrupted after walking through a doorway. Importantly, the magnitude of this disruption was similar in the 2 age groups. This is consistent with the idea that processing at the event level is relatively unaffected by the natural aging process. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

On the paleoenvironmental potential of 253 newly discovered pine stumps from Zurich, Switzerland

Science.gov (United States)

Reinig, Frederick; Nievergelt, Daniel; Esper, Jan; Friedrich, Michael; Helle, Gerhard; Hellmann, Lena; Kromer, Bernd; Morganti, Sandro; Pauly, Maren; Sookdeo, Adam; Tegel, Willy; Treydte, Kerstin; Wacker, Lukas; Büntgen, Ulf

2017-04-01

The transition from the last Ice Age to the early Holocene 15'000-10'000 BP represents a close natural analog to the ongoing and predicted rates of anthropogenic climate change. A reduced quality and quantity of high-resolution proxy archives during this period, however, limits our understanding of the magnitude and pace of Late Glacial (LG) environmental variability. Here, we present the world's best preserved, most replicated and oldest forest remains: A total of 253 subfossil pine stumps were recently discovered in Zurich. The combined approach of tree-ring and radiocarbon (14C) measurements results in an absolutely dated Preboreal Swiss tree-ring width chronology and eight floating chronologies. With tree ages ranging between 41 and 506 years, often including pith and bark, and a mean segment length of 163 years, this exceptional find is distributed over nearly 2'000 years between the Allerød and the Preboreal. Together with 200 previously collected LG pines from the greater Zurich region, this study sets a benchmark in terms of sample replication and dating precision for stable more dynamic climatic periods such as the Laacher See eruption, the Older and Younger Dryas. The paleoenvironmental significance would even increase when annually resolved 14C-measurements help fixing a major, Northern Hemispheric gap in the absolutely dated dendro time series during the Younger Dryas. While overcoming this interlude, our results further emphasize the importance of interdisciplinary research on these striking LG climatic shifts to better understand and assess their ecological and environmental impact.

Category learning strategies in younger and older adults: Rule abstraction and memorization.

Science.gov (United States)

Wahlheim, Christopher N; McDaniel, Mark A; Little, Jeri L

2016-06-01

Despite the fundamental role of category learning in cognition, few studies have examined how this ability differs between younger and older adults. The present experiment examined possible age differences in category learning strategies and their effects on learning. Participants were trained on a category determined by a disjunctive rule applied to relational features. The utilization of rule- and exemplar-based strategies was indexed by self-reports and transfer performance. Based on self-reported strategies, the frequencies of rule- and exemplar-based learners were not significantly different between age groups, but there was a significantly higher frequency of intermediate learners (i.e., learners not identifying with a reliance on either rule- or exemplar-based strategies) in the older than younger adult group. Training performance was higher for younger than older adults regardless of the strategy utilized, showing that older adults were impaired in their ability to learn the correct rule or to remember exemplar-label associations. Transfer performance converged with strategy reports in showing higher fidelity category representations for younger adults. Younger adults with high working memory capacity were more likely to use an exemplar-based strategy, and older adults with high working memory capacity showed better training performance. Age groups did not differ in their self-reported memory beliefs, and these beliefs did not predict training strategies or performance. Overall, the present results contradict earlier findings that older adults prefer rule- to exemplar-based learning strategies, presumably to compensate for memory deficits. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Applying Biomimetic Algorithms for Extra-Terrestrial Habitat Generation

Science.gov (United States)

Birge, Brian

2012-01-01

The objective is to simulate and optimize distributed cooperation among a network of robots tasked with cooperative excavation on an extra-terrestrial surface. Additionally to examine the concept of directed Emergence among a group of limited artificially intelligent agents. Emergence is the concept of achieving complex results from very simple rules or interactions. For example, in a termite mound each individual termite does not carry a blueprint of how to make their home in a global sense, but their interactions based strictly on local desires create a complex superstructure. Leveraging this Emergence concept applied to a simulation of cooperative agents (robots) will allow an examination of the success of non-directed group strategy achieving specific results. Specifically the simulation will be a testbed to evaluate population based robotic exploration and cooperative strategies while leveraging the evolutionary teamwork approach in the face of uncertainty about the environment and partial loss of sensors. Checking against a cost function and 'social' constraints will optimize cooperation when excavating a simulated tunnel. Agents will act locally with non-local results. The rules by which the simulated robots interact will be optimized to the simplest possible for the desired result, leveraging Emergence. Sensor malfunction and line of sight issues will be incorporated into the simulation. This approach falls under Swarm Robotics, a subset of robot control concerned with finding ways to control large groups of robots. Swarm Robotics often contains biologically inspired approaches, research comes from social insect observation but also data from among groups of herding, schooling, and flocking animals. Biomimetic algorithms applied to manned space exploration is the method under consideration for further study.

From Fossils to Astrobiology Records of Life on Earth and Search for Extraterrestrial Biosignatures

CERN Document Server

Seckbach, Joseph

2008-01-01

From Fossils to Astrobiology reviews developments in paleontology and geobiology that relate to the rapidly-developing field of Astrobiology, the study of life in the Universe. Many traditional areas of scientific study, including astronomy, chemistry and planetary science, contribute to Astrobiology, but the study of the record of life on planet Earth is critical in guiding investigations in the rest of the cosmos. In this varied book, expert scientists from 15 countries present peer-reviewed, stimulating reviews of paleontological and astrobiological studies. The overviews of established and emerging techniques for studying modern and ancient microorganisms on Earth and beyond, will be valuable guides to evaluating biosignatures which could be found in the extraterrestrial surface or subsurface within the Solar System and beyond. This volume also provides discussion on the controversial reports of "nanobacteria" in the Martian meteorite ALH84001. It is a unique volume among Astrobiology monographs in focusi...

Polyphase-discrete Fourier transform spectrum analysis for the Search for Extraterrestrial Intelligence sky survey

Science.gov (United States)

Zimmerman, G. A.; Gulkis, S.

1991-01-01

The sensitivity of a matched filter-detection system to a finite-duration continuous wave (CW) tone is compared with the sensitivities of a windowed discrete Fourier transform (DFT) system and an ideal bandpass filter-bank system. These comparisons are made in the context of the NASA Search for Extraterrestrial Intelligence (SETI) microwave observing project (MOP) sky survey. A review of the theory of polyphase-DFT filter banks and its relationship to the well-known windowed-DFT process is presented. The polyphase-DFT system approximates the ideal bandpass filter bank by using as few as eight filter taps per polyphase branch. An improvement in sensitivity of approx. 3 dB over a windowed-DFT system can be obtained by using the polyphase-DFT approach. Sidelobe rejection of the polyphase-DFT system is vastly superior to the windowed-DFT system, thereby improving its performance in the presence of radio frequency interference (RFI).

Late-Glacial radiocarbon- and palynostratigraphy in the Swiss Plateau

International Nuclear Information System (INIS)

Ammann, B.; Lotter, A.F.

1989-01-01

A detailed Late-Glacial radiocarbon stratigraphy for the Swiss Plateau has been established on the basis of over 90 accelerator 14 C dates on terrestrial plant macrofossils. A comparison of the radiocarbon ages derived from terrestrial, telmatic and limnic material at different sites on the Swiss Plateau yields a proposal for modifying the zonation system of Welten for the Late-Glacial. By retaining the limits of chronozones and by refining the palynostratigraphic criteria for the limits of biozones, a separation between chrono- and biozonation at the beginning of the Boelling and the Younger Dryas becomes obvious. 54 refs

Testing the Limits of Optimizing Dual-Task Performance in Younger and Older Adults

Science.gov (United States)

Strobach, Tilo; Frensch, Peter; Müller, Herrmann Josef; Schubert, Torsten

2012-01-01

Impaired dual-task performance in younger and older adults can be improved with practice. Optimal conditions even allow for a (near) elimination of this impairment in younger adults. However, it is unknown whether such (near) elimination is the limit of performance improvements in older adults. The present study tests this limit in older adults under conditions of (a) a high amount of dual-task training and (b) training with simplified component tasks in dual-task situations. The data showed that a high amount of dual-task training in older adults provided no evidence for an improvement of dual-task performance to the optimal dual-task performance level achieved by younger adults. However, training with simplified component tasks in dual-task situations exclusively in older adults provided a similar level of optimal dual-task performance in both age groups. Therefore through applying a testing the limits approach, we demonstrated that older adults improved dual-task performance to the same level as younger adults at the end of training under very specific conditions. PMID:22408613

Screening for autism in older and younger toddlers with the Modified Checklist for Autism in Toddlers.

Science.gov (United States)

Pandey, Juhi; Verbalis, Alyssa; Robins, Diana L; Boorstein, Hilary; Klin, A M I; Babitz, Tammy; Chawarska, Katarzyna; Volkmar, Fred; Green, James; Barton, Marianne; Fein, Deborah

2008-09-01

The Modified Checklist for Autism in Toddlers (M-CHAT) was used to screen younger (16-23 months) versus older (24-30 months) high- and low-risk toddlers. Refusal rates for follow-up interview showed no group differences, but parents of younger/low-risk children were more likely to refuse evaluation than parents of high-risk children. PPP for an ASD diagnosis was: younger/high-risk 0.79, older/high-risk 0.74, younger/low-risk 0.28, and older/low-risk 0.61, with PPP differing by age within the low-risk group. Most of the children in all groups, however, were diagnosed with a developmental disorder. Symptom severity generally did not differ among groups. Cognitive and adaptive measures showed minimal group differences. Therefore, older and younger toddlers had similar symptomatology and developmental delays; PPP for ASD is better at 24 than 18 months for low-risk children; however, these children are still highly likely to show a developmental disorder. Clinical decision making should balance early identification against the lower specificity of M-CHAT screening for the younger/low-risk group.

The -Younger-Minority Boy" as a Clue to the Source of Achievement Orientation.

Science.gov (United States)

Kammeyer, Kenneth C. W.

This study is a follow-up of the work by Morris Rosenberg who found that younger-minority boys tend to have high self-esteem, but a relatively low achievement orientation and low grades in school. Sampling a total 898 high school senior boys, this study found that younger minority boys do have lower grades and lower occupational and educational…

Study of extraterrestrial disposal of radioactive wastes. Part 2: Preliminary feasibility screening study of extraterrestrial disposal of radioactive wastes in concentrations, matrix materials, and containers designed for storage on earth

Science.gov (United States)

Hyland, R. E.; Wohl, M. L.; Thompson, R. L.; Finnegan, P. M.

1972-01-01

The results are reported of a preliminary feasibility screening study for providing long-term solutions to the problems of handling and managing radioactive wastes by extraterrestrial transportation of the wastes. Matrix materials and containers are discussed along with payloads, costs, and destinations for candidate space vehicles. The conclusions reached are: (1) Matrix material such as spray melt can be used without exceeding temperature limits of the matrix. (2) The cost in mills per kw hr electric, of space disposal of fission products is 4, 5, and 28 mills per kw hr for earth escape, solar orbit, and solar escape, respectively. (3) A major factor effecting cost is the earth storage time. Based on a normal operating condition design for solar escape, a storage time of more than sixty years is required to make the space disposal charge less than 10% of the bus-bar electric cost. (4) Based on a 10 year earth storage without further processing, the number of shuttle launches required would exceed one per day.

[The importance of wear couples for younger endoprosthesis patients].

Science.gov (United States)

Kircher, J; Bergschmidt, P; Bader, R; Kluess, D; Besser-Mahuzir, E; Leder, A; Mittelmeier, W

2007-04-01

The success and long-term survival rates of modern joint arthroplasty leads to a high patient satisfaction and, together with its technical improvements, has broadened the indications to an increasingly younger population. Limitations to the established systems are the long-term survival rates, which are mainly influenced by wear of the articulating parts and the resulting problems. Beside "classic" long-stemmed cemented shafts articulating with metal against polyethylene, short-stemmed or cup designs with a hard-hard self pairing are increasingly used in total hip arthroplasty. This paper reflects the current state of the art in joint arthroplasty for younger patients with the focus on wear couples and discusses future perspectives. Special interest is focused on the advantages and disadvantages of ceramic bearings, problems with allergies to implant components and the design of endoprostheses with regard to avoidance of impingement.

Efficacy and safety of tofacitinib in older and younger patients with rheumatoid arthritis.

Science.gov (United States)

Curtis, Jeffrey R; Schulze-Koops, Hendrik; Takiya, Liza; Mebus, Charles A; Terry, Ketti K; Biswas, Pinaki; Jones, Thomas V

2017-01-01

Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). We evaluated the efficacy and safety of tofacitinib 5 or 10 mg twice daily (BID), in patients with moderate to severe RA, aged ≥65 and tofacitinib, or placebo (Phase 3 only), with/without conventional synthetic DMARDs (mainly methotrexate). Clinical efficacy outcomes from Phase 3 studies were evaluated at Month 3. Safety evaluations using pooled Phase 3 data (Month 12) and pooled LTE data (Month 24) compared exposure-adjusted incidence rates (IRs; with 95% confidence intervals [CIs]), in older versus younger patients. In Phase 3 and LTE studies, 15.3% (475/3111) and 16.1% (661/4102) of patients, respectively, were aged ≥65 years. Consequently, exposure to tofacitinib was lower in older versus younger patients in Phase 3 (259.2 vs. 1554.9 patient years [pt-yrs]) and LTE (962.1 vs. 5071.7 pt-yrs) studies. Probability ratios for ACR responses and HAQ-DI improvement from baseline ≥0.22 (Month 3) favoured tofacitinib and were similar in older and younger patients, with overlapping CIs. IRs for SAEs and discontinuations due to AEs were generally numerically higher in older versus younger patients, irrespective of treatment. Older patients receiving tofacitinib 5 or 10 mg BID had a similar probability of ACR20 or ACR50 response and, due to comorbidities, a numerically higher risk of SAEs and discontinuations due to AEs compared with younger patients.

Stereotypes of older employees compared to younger employees in Slovenian companies

Directory of Open Access Journals (Sweden)

Maja Rožman

2016-01-01

Full Text Available Human resource management has an important impact on age diversity in companies. Age diversity in the workplace is growing and older employees are staying longer in the workforce, therefore it is important that employers can create a positive environment for age diverse employees. This paper introduces the difference in stereotypes in the workplace between older and younger employees in Slovenian companies. The main goal of this paper is to present the importance of age diversity and their age difference in stereotypes in the workplace. The paper is based on a research including a survey between two age groups of employees. We classified younger employees in the group of under 50 years of age and older employees in the group of above 50 years of age. For data analysis we used the non-parametric Mann-Whitney U test to verify the differences in stereotypes in the workplace between two groups. Results show that there are significant differences in all of the variables describing stereotypes in the workplace between younger and older employees in Slovenian companies.

Icon arrays help younger children's proportional reasoning.

Science.gov (United States)

Ruggeri, Azzurra; Vagharchakian, Laurianne; Xu, Fei

2018-06-01

We investigated the effects of two context variables, presentation format (icon arrays or numerical frequencies) and time limitation (limited or unlimited time), on the proportional reasoning abilities of children aged 7 and 10 years, as well as adults. Participants had to select, between two sets of tokens, the one that offered the highest likelihood of drawing a gold token, that is, the set of elements with the greater proportion of gold tokens. Results show that participants performed better in the unlimited time condition. Moreover, besides a general developmental improvement in accuracy, our results show that younger children performed better when proportions were presented as icon arrays, whereas older children and adults were similarly accurate in the two presentation format conditions. Statement of contribution What is already known on this subject? There is a developmental improvement in proportional reasoning accuracy. Icon arrays facilitate reasoning in adults with low numeracy. What does this study add? Participants were more accurate when they were given more time to make the proportional judgement. Younger children's proportional reasoning was more accurate when they were presented with icon arrays. Proportional reasoning abilities correlate with working memory, approximate number system, and subitizing skills. © 2018 The British Psychological Society.

A qualitative study of younger men's experience of heart attack (myocardial infarction).

Science.gov (United States)

Merritt, Christopher J; de Zoysa, Nicole; Hutton, Jane M

2017-09-01

The effects of heart attack, or myocardial infarction (MI), across psychosocial domains may be particularly acute in younger adults, for whom serious health events are non-normative. MI morbidity is declining in Western countries, but in England MI numbers have plateaued for the under-45 cohort, where approximately 90% of patients are male. Qualitative research on younger adults' experience of MI is limited, and no study has sampled exclusively under-45s. This study aimed to understand how a sample of men under 45 adjusted to and made sense of MI. Qualitative research design based on semi-structured in-depth interviews. Ten men aged under 45 who had experienced MI in the past 3-6 months were purposively recruited and interviewed. Interviews were transcribed verbatim and analysed using interpretative phenomenological analysis. Seven superordinate themes were identified. This article focuses in depth on the three most original themes: (1) 'I'm less of a man', which described experiences of losing 'maleness' (strength, independence, ability to provide) post-MI; (2) 'Shortened horizons', which covered participants' sense of foreshortened future and consequent reprioritization; and (3) 'Life loses its colour', describing the loss of pleasure from lifestyle-related changes. Themes broadly overlapped with the qualitative literature on younger adult MI. However, some themes (e.g., loss of 'maleness' post-MI, and ambivalence towards MI risk factors) appeared unique to this study. Themes were also discussed in relation to risk factors for anxiety and depression and how this might inform clinical care for a younger, male population. Statement of contribution What is already known on this subject? Myocardial infarction (MI) morbidity is not declining in England for under-45s. Adjustment to MI is particularly challenging for younger adults, perhaps because it is non-normative. However, little is known about the experience of MI in younger adults. What does this study add? This

CENTAR code for extended nonlinear transient analysis of extraterrestrial reactor systems

International Nuclear Information System (INIS)

Nassersharif, B.; Peer, J.S.; DeHart, M.D.

1987-01-01

Current interest in the application of nuclear reactor-driven power systems to space missions has generated a need for a systems simulation code to model and analyze space reactor systems; such a code has been initiated at Texas A and M, and the first version is nearing completion; release was anticipated in the fall of 1987. This code, named CENTAR (Code for Extended Nonlinear Transient Analysis of Extraterrestrial Reactor Systems), is designed specifically for space systems and is highly vectorizable. CENTAR is composed of several specialized modules. A fluids module is used to model fluid behavior throughout the system. A wall heat transfer module models the heat transfer characteristics of all walls, insulation, and structure around the system. A fuel element thermal analysis module is used to predict the temperature behavior and heat transfer characteristics of the reactor fuel rods. A kinetics module uses a six-group point kinetics formulation to model reactivity feedback and control and the ANS 5.1 decay-heat curve to model shutdown decay-heat production. A pump module models the behavior of thermoelectric-electromagnetic pumps, and a heat exchanger module models not only thermal effects in thermoelectric heat exchangers, but also predicts electrical power production for a given configuration. Finally, an accumulator module models coolant expansion/contraction accumulators

If technological intelligent extraterrestrials exist, what biological traits are de rigueur

Science.gov (United States)

Taylor, E. R.

2018-05-01

If extraterrestrials exist in the depths of cosmic space, and are capable of interstellar communications, even space flight, there is no requirement that they be humanoid in form. However, certain humanoid capabilities would be advantageous for tool fashioning and critical to operating space craft as well as functioning under the disparate extreme conditions under which they may be forced to operate. They would have to be "gas breathing". The reasonable assumption that life based upon the same elements as Earth life requiring water stems from the unique properties of water that no other similar low molecular weight nonmetal hydride offers. Only water offers the diversity of chemical properties and reactivity, including the existence of the three common physical states within a limited temperature range of service to life, avoiding the issues presented by any alternatives. They must, like us, possess a large, abstract-thinking brain, and probably possess at least all the fundamental senses that humankind possess. They would also be carbon-based life, using oxygen as the electron sink of their biochemistry for the reasons considered. They most likely are homeothermic as us, though they may not necessarily be mammalian as we are. Their biochemistry could differ some from ours, perhaps presenting contact hazards for both species as discussed.

Thermal Design for Extra-Terrestrial Regenerative Fuel Cell System

Science.gov (United States)

Gilligan, R.; Guzik, M.; Jakupca, I.; Bennett, W.; Smith, P.; Fincannon, J.

2017-01-01

The Advanced Exploration Systems (AES) Advanced Modular Power Systems (AMPS) Project is investigating different power systems for various lunar and Martian mission concepts. The AMPS Fuel Cell (FC) team has created two system-level models to evaluate the performance of regenerative fuel cell (RFC) systems employing different fuel cell chemistries. Proton Exchange Membrane fuel cells PEMFCs contain a polymer electrolyte membrane that separates the hydrogen and oxygen cavities and conducts hydrogen cations (protons) across the cell. Solid Oxide fuel cells (SOFCs) operate at high temperatures, using a zirconia-based solid ceramic electrolyte to conduct oxygen anions across the cell. The purpose of the modeling effort is to down select one fuel cell chemistry for a more detailed design effort. Figures of merit include the system mass, volume, round trip efficiency, and electrolyzer charge power required. PEMFCs operate at around 60 C versus SOFCs which operate at temperatures greater than 700 C. Due to the drastically different operating temperatures of the two chemistries the thermal control systems (TCS) differ. The PEM TCS is less complex and is characterized by a single pump cooling loop that uses deionized water coolant and rejects heat generated by the system to the environment via a radiator. The solid oxide TCS has its own unique challenges including the requirement to reject high quality heat and to condense the steam produced in the reaction. This paper discusses the modeling of thermal control systems for an extraterrestrial RFC that utilizes either a PEM or solid oxide fuel cell.

Table for monthly average daily extraterrestrial irradiation on horizontal surface and the maximum possible sunshine duration

International Nuclear Information System (INIS)

Jain, P.C.

1984-01-01

The monthly average daily values of the extraterrestrial irradiation on a horizontal surface (H 0 ) and the maximum possible sunshine duration are two important parameters that are frequently needed in various solar energy applications. These are generally calculated by scientists each time they are needed and by using the approximate short-cut methods. Computations for these values have been made once and for all for latitude values of 60 deg. N to 60 deg. S at intervals of 1 deg. and are presented in a convenient tabular form. Values of the maximum possible sunshine duration as recorded on a Campbell Stoke's sunshine recorder are also computed and presented. These tables should avoid the need for repetition and approximate calculations and serve as a useful ready reference for solar energy scientists and engineers. (author)

Extraterrestrial intelligence and human imagination SETI at the intersection of science, religion, and culture

CERN Document Server

Traphagan, John

2015-01-01

The search for extraterrestrial intelligence (SETI) represents one of the most significant crossroads at which the assumptions and methods of scientific inquiry come into direct contact with—and in many cases conflict with—those of religion. Indeed, at the core of SETI is the same question that motivates many interested in religion: What is the place of humanity in the universe? Both scientists involved with SETI (and in other areas) and those interested in and dedicated to some religious traditions are engaged in contemplating these types of questions, even if their respective approaches and answers differ significantly. This book explores this intersection with a focus on three core points: 1) the relationship between science and religion as it is expressed within the framework of SETI research, 2) the underlying assumptions, many of which are tacitly based upon cultural values common in American society, that have shaped the ways in which SETI researchers have conceptualized the nature of their endeavo...

Nuclear reactor closed Brayton cycle power conversion system optimization trends for extra-terrestrial applications

International Nuclear Information System (INIS)

Ashe, T.L.; Baggenstoss, W.G.; Bons, R.

1990-01-01

Extra-terrestrial exploration and development missions of the next century will require reliable, low-mass power generation modules of 100 kW e and more. These modules will be required to support both fixed-base and manned rover/explorer power needs. Low insolation levels at and beyond Mars and long periods of darkness on the moon make solar conversion less desirable for surface missions. For these missions, a closed Brayton cycle energy conversion system coupled with a reactor heat source is a very attractive approach. The authors conducted parametric studies to assess optimized system design trends for nuclear-Brayton systems as a function of operating environment and user requirements. The inherent design flexibility of the closed Brayton cycle energy conversion system permits ready adaptation of the system to future design constraints. This paper describes a dramatic contrast between system designs requiring man-rated shielding. The paper also considers the ramification of using indigenous materials to provide reactor shielding for a fixed-base power source

Accurate computations of monthly average daily extraterrestrial irradiation and the maximum possible sunshine duration

International Nuclear Information System (INIS)

Jain, P.C.

1985-12-01

The monthly average daily values of the extraterrestrial irradiation on a horizontal plane and the maximum possible sunshine duration are two important parameters that are frequently needed in various solar energy applications. These are generally calculated by solar scientists and engineers each time they are needed and often by using the approximate short-cut methods. Using the accurate analytical expressions developed by Spencer for the declination and the eccentricity correction factor, computations for these parameters have been made for all the latitude values from 90 deg. N to 90 deg. S at intervals of 1 deg. and are presented in a convenient tabular form. Monthly average daily values of the maximum possible sunshine duration as recorded on a Campbell Stoke's sunshine recorder are also computed and presented. These tables would avoid the need for repetitive and approximate calculations and serve as a useful ready reference for providing accurate values to the solar energy scientists and engineers

Systemic therapy in younger and elderly patients with advanced biliary cancer

DEFF Research Database (Denmark)

McNamara, Mairéad Geraldine; Bridgewater, John; Lopes, Andre

2017-01-01

BACKGROUND: Outcomes in younger (ABC) receiving palliative chemotherapy are unclear. This study assessed outcomes in those receiving monotherapy or combination therapy in thirteen prospective systemic-therapy trials. METHODS......: Multivariable analysis explored the impact of therapy on progression-free (PFS) and overall survival (OS) in two separate age cohort groups: ... = 0.58, P = 0.66) or OS (P = 0.18, P = 0.75). CONCLUSIONS: In ABC, younger patients are rare, and survival in elderly patients in receipt of systemic therapy for advanced disease, whether monotherapy or combination therapy, is similar to that of non-elderly patients, therefore age alone should...

Pioglitazone is equally effective for diabetes prevention in older versus younger adults with impaired glucose tolerance.

Science.gov (United States)

Espinoza, Sara E; Wang, Chen-Pin; Tripathy, Devjit; Clement, Stephen C; Schwenke, Dawn C; Banerji, Mary Ann; Bray, George A; Buchanan, Thomas A; Henry, Robert R; Kitabchi, Abbas E; Mudaliar, Sunder; Stentz, Frankie B; Reaven, Peter D; DeFronzo, Ralph A; Musi, Nicolas

2016-12-01

To determine the efficacy of pioglitazone to prevent type 2 diabetes in older compared to younger adults with pre-diabetes. Six hundred two participants with impaired glucose tolerance (IGT) were randomized in double blind fashion to placebo or pioglitazone for diabetes prevention in the ACT NOW study (NEJM 364:1104-1115, 2011). Cox proportional hazard regression was used to compare time to development of diabetes over a mean of 2 years between older (≥61 years) and younger participants. We compared effects of pioglitazone versus placebo on metabolic profiles, inflammatory markers, adipokines, β cell function (disposition index), insulin sensitivity (Matsuda index), and body composition by ANOVA. Diabetes incidence was reduced by 85 % in older and 69 % in younger subjects (p = 0.41). β cell function (disposition index) increased by 35.0 % in the older and 26.7 % in younger subjects (p = 0.83). Insulin sensitivity (Matsuda index) increased by 3.07 (5.2-fold) in older and by 2.54 (3.8-fold) in younger participants (p = 0.58). Pioglitazone more effectively increased adiponectin in older versus younger subjects (22.9 ± 3.2 μg/mL [2.7-fold] vs. 12.7 ± 1.4 μg/mL [2.2-fold], respectively; p = 0.04). Younger subjects tended to have a greater increase in whole body fat mass compared to older subjects (3.6 vs. 3.1 kg; p = 0.061). Younger and older subjects had similar decreases in bone mineral density (0.018 ± 0.0071 vs. 0.0138 ± 0.021 g/cm 2 ). Younger and older pre-diabetic adults taking pioglitazone had similar reductions in conversion to diabetes and older adults had similar or greater improvements in metabolic risk factors, demonstrating that pioglitazone is useful in preventing diabetes in older adults.

Deep-sea spherules from Pacific clay - Mass distribution and influx rate. [extraterrestrial origins from optical and electron microscopy

Science.gov (United States)

Murrell, M. T.; Davis, P. A., Jr.; Nishiizumi, K.; Millard, H. T., Jr.

1980-01-01

From 411 kg of Pacific clay, 22 mg of stony spherules and 50 mg of iron spherules larger than 150 microns were concentrated. The extraterrestrial origin of these particles was evaluated with the aid of optical and electron microscopy and atomic absorption elemental analysis. An expression for the integral number of stony particles from this sediment in the mass range 20-300 micrograms was derived. The world-wide influx rate of stony particles in the mass range which survive atmospheric heating and ocean sediment storage is calculated to be 90 tons/yr. The relative contributions of ablation debris vs fused interplanetary dust to the influx of stony spherules is discussed, but no conclusions could be made.

Situation Selection and Modification for Emotion Regulation in Younger and Older Adults.

Science.gov (United States)

Livingstone, Kimberly M; Isaacowitz, Derek M

2015-11-01

This research investigated age differences in use and effectiveness of situation selection and situation modification for emotion regulation. Socioemotional selectivity theory suggests stronger emotional well-being goals in older age; emotion regulation may support this goal. Younger and older adults assigned to an emotion regulation or "just view" condition first freely chose to engage with negative, neutral, or positive material (situation selection), then chose to view or skip negative and positive material (situation modification), rating affect after each experience. In both tasks, older adults in both goal conditions demonstrated pro-hedonic emotion regulation, spending less time with negative material compared to younger adults. Younger adults in the regulate condition also engaged in pro-hedonic situation selection, but not modification. Whereas situation selection was related to affect, modification of negative material was not. This research supports more frequent pro-hedonic motivation in older age, as well as age differences in use of early-stage emotion regulation.

The younger siblings of teenage mothers: a follow-up of their pregnancy risk.

Science.gov (United States)

East, P L; Jacobson, L J

2001-03-01

This study followed 243 younger brothers and younger sisters of parenting teens and nonparenting teens across a 1.5-year period. The average age of siblings was 13.6 years at Time 1 and 15 years at Time 2. Relative to other youths, the sisters of parenting teens exhibited a sharp increase in drug and alcohol use and partying behavior across time and had the highest pregnancy rate at Time 2 (15%). The siblings of parenting teens spent 10 hr a week caring for their sisters' children, and, for girls, many hours of child care was associated with negative outcomes including permissive sexual behavior. Findings suggest that the younger sisters of parenting teens are at very high risk of early pregnancy and that this risk becomes increasingly pronounced across time.

Effects of Vocal Emotion on Memory in Younger and Older Adults.

Science.gov (United States)

Pichora-Fuller, M Kathleen; Dupuis, Kate; Smith, Sherri L

2016-01-01

Emotional content can enhance memory for visual stimuli, and older adults often perform better if stimuli portray positive emotion. Vocal emotion can enhance the accuracy of word repetition in noise when vocal prosody portrays attention-capturing emotions such as fear and pleasant surprise. In the present study, the authors examined the effect of vocal emotion on the accuracy of repetition and recall in younger and older adults when words are presented in quiet or in a background of competing babble. Younger and older adults (Mage = 20 and 72 years, respectively) participated. Lists of 100 items (carrier phrase plus target word) were presented in recall sets of increasing size. Word repetition accuracy was tested after each item and recall after each trial in each set size. In Experiment 1, one list spoken in a neutral voice and another with emotion (fear, pleasant surprise, sad, neutral) were presented in quiet (n = 24 per group). In Experiment 2, participants (n = 12 per group) were presented the emotional list in noise. In quiet, word repetition accuracy was near perfect for both groups and did not vary systematically with set size for the list spoken in a neutral voice; however, for the emotional list, repetition was less accurate, especially for the older group. Recall in quiet was higher for younger than older adults; collapsed over groups, recall was higher for the neutral than for the emotional list and it decreased with increasing set size. In noise, emotion-specific effects emerged; word repetition for the older group and word recall for both groups (more for younger than older) was best for fear or pleasant surprise and worst for sad. In quiet, vocal emotion reduced the word repetition accuracy of the older group and recall accuracy for both groups. In noise, there were emotion-specific effects on the repetition accuracy of older adults and the recall accuracy of both groups. Both groups, but especially the younger group, performed better for items

The Experiences of the Younger Supervisor: Implications for Organizations

Science.gov (United States)

Hanson, Lea

2012-01-01

With four generations in today's workforce, roles are being redefined to include a growing number of younger supervisor/older subordinate relationships, referred to as the intergenerational dyad. What current and limited literature exists about the intergenerational dyad exclusively addresses the issues of generational workplace differences…

Detection of Extraterrestrial Civilizations via the Spectral Signature of Advanced Interstellar Spacecraft

Science.gov (United States)

Zubrin, Robert

1994-07-01

This paper examines the possibility of detecting extraterrestrial civilizations by means of searching for the spectral signature of their interstellar transportation systems. The advantage of such an approach is that the characteristic power levels associated with interstellar transportation systems are many orders of magnitude greater than those required for communication, and so the signal strength may be much greater. Furthermore, unlike communication which is governed by a fairly arbitrary selection of technology and mutually agreed upon conventions, interstellar transportation systems are governed much more stringently by the laws of physics. For purposes of the present analysis we consider 4 methods of interstellar propulsion, the principles of which are fairly well understood. These are anti-matter rockets, fusion rockets, fission rockets, all of which can be used to either accelerate or decelerate a spacecraft, and magnetic sails, which can be used to decelerate a spacecraft by creating drag against the interstellar medium. The types of radiation emitted by each of these propulsion systems is described, and the signal strength for starships of a characteristic mass of 1 million tonnes traveling at speeds and acceleration levels characteristic of the various propulsion systems is estimated. It is shown that for the power level of ships considered, the high energy gamma radiation emitted by the anti-matter, fusion and fission propulsion systems would be undetectable at interstellar distances. Better opportunities for detection would be the bremsstrahlung radiation from the plasma confinement systems of fusion devices, which might be detectable at distances of about 1 light year, and visible light emitted from the radiators of anti-matter driven photon rocket, which might be detectable by the Hubble Space Telescope at a distance of several hundred light years provided the rocket nozzle is oriented towards the Earth. The most detectable form of starship

Could an airburst above Canada at the Younger Dryas onset trigger lake eutrophication and acidification in central Europe?

Czech Academy of Sciences Publication Activity Database

Stuchlík, Evžen; Kletetschka, G.; Hořická, Zuzana; Hrubá, J.; Nábělek, L.; Svitavská-Svobodová, Helena; Bobek, Přemysl; Kadlec, Jaroslav; Takac, M.; Vondrák, D.

2017-01-01

Roč. 52, S1 (2017), A335-A335, č. článku 6247. ISSN 1086-9379. [Annual Meeting of the Meteoritical Society /80./. 23.07.2017-28.07.2017, Santa Fe] R&D Projects: GA ČR(CZ) GA17-05935S Institutional support: RVO:60077344 ; RVO:67985939 ; RVO:67985530 Keywords : airburst * lake * eutrophication * acidification * paleolimnology Subject RIV: DA - Hydrology ; Limnology; EH - Ecology, Behaviour (BU-J)

Trends in colorectal cancer incidence among younger adults-Disparities by age, sex, race, ethnicity, and subsite.

Science.gov (United States)

Crosbie, Amanda B; Roche, Lisa M; Johnson, Linda M; Pawlish, Karen S; Paddock, Lisa E; Stroup, Antoinette M

2018-06-22

Millennials (ages 18-35) are now the largest living generation in the US, making it important to understand and characterize the rising trend of colorectal cancer incidence in this population, as well as other younger generations of Americans. Data from the New Jersey State Cancer Registry (n = 181 909) and Surveillance, Epidemiology, and End Results program (n = 448 714) were used to analyze invasive CRC incidence trends from 1979 to 2014. Age, sex, race, ethnicity, subsite, and stage differences between younger adults (20-49) and screening age adults (≥50) in New Jersey (NJ) were examined using chi-square; and, we compared secular trends in NJ to the United States (US). Whites, men, and the youngest adults (ages 20-39) are experiencing greater APCs in rectal cancer incidence. Rates among younger black adults, overall, were consistently higher in both NJ and the US over time. When compared to older adults, younger adults with CRC in NJ were more likely to be: diagnosed at the late stage, diagnosed with rectal cancer, male, non-white, and Hispanic. Invasive CRC incidence trends among younger adults were found to vary by age, sex, race, ethnicity, and subsite. Large, case-level, studies are needed to understand the role of genetics, human papillomavirus (HPV), and cultural and behavioral factors in the rise of CRC among younger adults. Provider and public education about CRC risk factors will also be important for preventing and reversing the increasing CRC trend in younger adults. © 2018 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Archaeal community changes in Lateglacial lake sediments: Evidence from ancient DNA

Science.gov (United States)

Ahmed, Engy; Parducci, Laura; Unneberg, Per; Ågren, Rasmus; Schenk, Frederik; Rattray, Jayne E.; Han, Lu; Muschitiello, Francesco; Pedersen, Mikkel W.; Smittenberg, Rienk H.; Yamoah, Kweku Afrifa; Slotte, Tanja; Wohlfarth, Barbara

2018-02-01

The Lateglacial/early Holocene sediments from the ancient lake at Hässeldala Port, southern Sweden provide an important archive for the environmental and climatic shifts at the end of the last ice age and the transition into the present Interglacial. The existing multi-proxy data set highlights the complex interplay of physical and ecological changes in response to climatic shifts and lake status changes. Yet, it remains unclear how microorganisms, such as Archaea, which do not leave microscopic features in the sedimentary record, were affected by these climatic shifts. Here we present the metagenomic data set of Hässeldala Port with a special focus on the abundance and biodiversity of Archaea. This allows reconstructing for the first time the temporal succession of major Archaea groups between 13.9 and 10.8 ka BP by using ancient environmental DNA metagenomics and fossil archaeal cell membrane lipids. We then evaluate to which extent these findings reflect physical changes of the lake system, due to changes in lake-water summer temperature and seasonal lake-ice cover. We show that variations in archaeal composition and diversity were related to a variety of factors (e.g., changes in lake water temperature, duration of lake ice cover, rapid sediment infilling), which influenced bottom water conditions and the sediment-water interface. Methanogenic Archaea dominated during the Allerød and Younger Dryas pollen zones, when the ancient lake was likely stratified and anoxic for large parts of the year. The increase in archaeal diversity at the Younger Dryas/Holocene transition is explained by sediment infilling and formation of a mire/peatbog.

Comparing urban form correlations of the travel patterns of older and younger adults

DEFF Research Database (Denmark)

Meza, Maria Josefina Figueroa; Nielsen, Thomas Alexander Sick; Siren, Anu Kristiina

2014-01-01

Using disaggregated data from the Danish National Travel Survey conducted between 2006 - 2011, this study compares the travel patterns of older (65 – 84 years of age) and younger (18 – 64 years of age) adults regarding land use, socio-economic conditions and urban structures. The results highlight...... significant differences between travel patterns and their urban form correlates for the older and younger adult populations. Spatial variables such as density and regional accessibility have different and potentially reverse associations with travel among older adults. The car use of older adults...... is not substituted by other modes in high-density settings, as is the case for younger adults. Older adults do not respond to high regional accessibility by reducing distance traveled, but travel longer and are also more likely to continue using a car in high-access conditions. Spatial structural conditions have...

Reflections of distraction in memory: transfer of previous distraction improves recall in younger and older adults.

Science.gov (United States)

Thomas, Ruthann C; Hasher, Lynn

2012-01-01

Three studies explored whether younger and older adults' free recall performance can benefit from prior exposure to distraction that becomes relevant in a memory task. Participants initially read stories that included distracting text. Later, they studied a list of words for free recall, with half of the list consisting of previously distracting words. When the memory task was indirect in its use of distraction (Study 1), only older adults showed transfer, with better recall of previously distracting compared with new words, which increased their recall to match that of younger adults. However, younger adults showed transfer when cued about the relevance of previous distraction both before studying the words (Study 2) and before recalling the words (Study 3) in the memory test. Results suggest that both younger and older adults encode distraction, but younger adults require explicit cueing to use their knowledge of distraction. In contrast, older adults transfer knowledge of distraction in both explicitly cued and indirect memory tasks. Results are discussed in terms of age differences in inhibition and source-constrained retrieval.

Short-term and long-term collaboration benefits on individual recall in younger and older adults

Science.gov (United States)

Stern, Yaakov

2011-01-01

A recent study of younger adults suggests that, compared to repeated individual recall trials, repeated collaborative recall trials produce better individual recall after a short delay (Blumen & Rajaram, 2008). Our study was designed to determine if such collaboration benefits would remain after a one-week delay, in both younger and older adults. Sixty younger (M age = 24.60) and 60 older (M age = 67.35) adults studied a list of words and then completed either two collaborative recall trials followed by two individual recall trials, or four individual recall trials. A five-min delay was inserted between the first three recall trials. The fourth recall trial was administered 1 week later. Collaborative recall was completed in groups of three individuals working together. Both younger and older adults benefitted from repeated collaborative recall trials to a greater extent than repeated individual recall trials, and such collaboration benefits remained after a one-week delay. This is the first demonstration of collaboration benefits on later individual recall at delays as long as 1 week, in both younger and older adults. Findings are discussed within the context of the negative effects of collaboration associated with group memory (collaborative inhibition) and the positive effects of collaboration associated with later individual memory (collaboration benefits). PMID:21264617

Time perspective and social preference in older and younger adults: Effects of self-regulatory fatigue.

Science.gov (United States)

Segerstrom, Suzanne C; Geiger, Paul J; Combs, Hannah L; Boggero, Ian A

2016-09-01

Socioemotional selectivity theory predicts that when perceived time in life is limited, people will prefer emotionally close social partners over less emotionally rewarding partners. Regulating social choices with regard to time perspective can make the best use of time with regard to well-being. However, doing so may depend on the self-regulatory capacity of the individual. Two studies, 1 with younger adults (N = 101) and 1 with younger (N = 42) and older (N = 39) adults, experimentally tested the effects of time perspective and self-regulatory fatigue on preferences for emotionally close partners and knowledgeable partners. In both studies and across younger and older adults, when self-regulatory fatigue was low, the perception of limited time resulted in a greater preference for close social partners relative to knowledgeable social partners. However, this shift was eliminated by self-regulatory fatigue. In Study 2, when fatigued, younger adults preferred close social partners to knowledgeable partners across time perspectives; older adults preferred close and knowledgeable partners more equally across time perspectives. These findings have implications for social decision-making and satisfaction among people who experience chronic self-regulatory fatigue. They also contradict previous suggestions that only younger adults are susceptible to self-regulatory fatigue. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

The effect of exercise on affective and self-efficacy responses in older and younger women.

Science.gov (United States)

Barnett, Fiona

2013-01-01

This study examined the self-efficacy and affective responses to an acute exercise bout in sedentary older and younger women to determine whether aging has an effect on affective states. Twenty-five sedentary younger (mean age = 19.9 yrs) and 25 older (mean age = 55.7 yrs) women completed an acute bout of exercise. Affective responses were measured before, during, and immediately following exercise. Self-efficacy responses were measured before and immediately following exercise. Positive engagement, revitalization, tranquility, Felt Arousal and Feeling Scale responses, and self-efficacy were all higher immediately following compared with before or during exercise for both groups of women. In addition, older women experienced higher overall positive engagement and lower physical exhaustion compared with younger women as well as higher tranquility and Feeling Scale responses immediately following exercise. This investigation found that an acute bout of moderate-intensity exercise produced more positive and fewer negative affective states in both younger and older women.

Soil charcoal analysis as a climato-stratigraphical tool: The key case of Cordillera Real, northern Andes

Energy Technology Data Exchange (ETDEWEB)

Di Pasquale, G. [Dipartimento di Arboricoltura Botanica e Patologia Vegetale, Universita di Napoli Federico II, Via Universita 100, 80055 Portici (Italy); Impagliazzo, S., E-mail: stefania.impagliazzo@unina.i [Dipartimento di Arboricoltura Botanica e Patologia Vegetale, Universita di Napoli Federico II, Via Universita 100, 80055 Portici (Italy); Lubritto, C. [CIRCE, Dipartimento di Scienze Ambientali, II Universita di Napoli, and INNOVA, via Vivaldi, 43, 81100 Caserta (Italy); Marziano, M. [Dipartimento di Arboricoltura Botanica e Patologia Vegetale, Universita di Napoli Federico II, Via Universita 100, 80055 Portici (Italy); Passariello, I. [CIRCE, Dipartimento di Scienze Ambientali, II Universita di Napoli, and INNOVA, via Vivaldi, 43, 81100 Caserta (Italy); Ermolli, E. Russo [Dipartimento di Arboricoltura Botanica e Patologia Vegetale, Universita di Napoli Federico II, Via Universita 100, 80055 Portici (Italy)

2010-04-15

The present study represents the first attempt of reconstructing fire history through soil charcoal dating. The investigated area is located in the Guandera Biological Reserve (western Cordillera Real, northern Ecuador). Six AMS radiocarbon dating, performed at the base of five soil profiles allowed a fire phase to be identified during the Pleistocene-Holocene transition. A strong correspondence was highlighted between the age of the Guandera fires and the El Abra stadial, which is considered the Younger Dryas equivalent in South America. This local evidence of fires contributes to define the geographic area in which the El Abra stadial was recorded and suggests a wider use of the soil charcoal analysis.

Soil charcoal analysis as a climato-stratigraphical tool: The key case of Cordillera Real, northern Andes

International Nuclear Information System (INIS)

Di Pasquale, G.; Impagliazzo, S.; Lubritto, C.; Marziano, M.; Passariello, I.; Ermolli, E. Russo

2010-01-01

The present study represents the first attempt of reconstructing fire history through soil charcoal dating. The investigated area is located in the Guandera Biological Reserve (western Cordillera Real, northern Ecuador). Six AMS radiocarbon dating, performed at the base of five soil profiles allowed a fire phase to be identified during the Pleistocene-Holocene transition. A strong correspondence was highlighted between the age of the Guandera fires and the El Abra stadial, which is considered the Younger Dryas equivalent in South America. This local evidence of fires contributes to define the geographic area in which the El Abra stadial was recorded and suggests a wider use of the soil charcoal analysis.

The Greenland ice sheet - a model for its culmination and decay during and after the last glacial maximum

DEFF Research Database (Denmark)

Funder, Svend Visby; Hansen, Louise

1996-01-01

there was little change at all. The driving factor during this step was calving caused by rising sea level. This lasted until c. 10 ka, but may have been consumated before the Younger Dryas. The second step began with a glacier-readvance between 10 and 9.5 ka, and after this the fjord glaciers began to retreat....... Maximum Holocene uplift was attained in areas of the 10 ka ice margin, indicating that the uplift is essentially a response to the melting and unloading of ice that began at this time. In suppport of this, recent results in West, North and East Greenland indicate that the...

The prone bridge test: Performance, validity, and reliability among older and younger adults.

Science.gov (United States)

Bohannon, Richard W; Steffl, Michal; Glenney, Susan S; Green, Michelle; Cashwell, Leah; Prajerova, Kveta; Bunn, Jennifer

2018-04-01

The prone bridge maneuver, or plank, has been viewed as a potential alternative to curl-ups for assessing trunk muscle performance. The purpose of this study was to assess prone bridge test performance, validity, and reliability among younger and older adults. Sixty younger (20-35 years old) and 60 older (60-79 years old) participants completed this study. Groups were evenly divided by sex. Participants completed surveys regarding physical activity and abdominal exercise participation. Height, weight, body mass index (BMI), and waist circumference were measured. On two occasions, 5-9 days apart, participants held a prone bridge until volitional exhaustion or until repeated technique failure. Validity was examined using data from the first session: convergent validity by calculating correlations between survey responses, anthropometrics, and prone bridge time, known groups validity by using an ANOVA comparing bridge times of younger and older adults and of men and women. Test-retest reliability was examined by using a paired t-test to compare prone bridge times for Session1 and Session 2. Furthermore, an intraclass correlation coefficient (ICC) was used to characterize relative reliability and minimal detectable change (MDC 95% ) was used to describe absolute reliability. The mean prone bridge time was 145.3 ± 71.5 s, and was positively correlated with physical activity participation (p ≤ 0.001) and negatively correlated with BMI and waist circumference (p ≤ 0.003). Younger participants had significantly longer plank times than older participants (p = 0.003). The ICC between testing sessions was 0.915. The prone bridge test is a valid and reliable measure for evaluating abdominal performance in both younger and older adults. Copyright © 2017 Elsevier Ltd. All rights reserved.

Lung cancer in younger patients

DEFF Research Database (Denmark)

Abbasowa, Leda; Madsen, Poul Henning

2016-01-01

INTRODUCTION: Lung cancer remains a leading cause of cancer-related death. The incidence increases with age and the occurrence in young patients is relatively low. The clinicopathological features of lung cancer in younger patients have not been fully explored previously. METHODS: To assess the age...... differences in the clinical characteristics of lung cancer, we conducted a retrospective analysis comparing young patients ≤ 65 years of age with an elderly group > 65 years of age. Among 1,232 patients evaluated due to suspicion of lung cancer in our fast-track setting from January-December 2013, 312 newly...... diagnosed lung cancer patients were included. RESULTS: Patients ≤ 65 years had a significantly higher representation of females (p = 0.0021), more frequent familial cancer aggregation (p = 0.028) and a lower incidence of squamous cell carcinoma (p = 0.0133). When excluding pure carcinoid tumours...

Older and Younger Workers: The Equalling Effects of Health

Science.gov (United States)

Beck, Vanessa; Quinn, Martin

2012-01-01

Purpose: The purpose of this paper is to consider the statistical evidence on the effects that ill health has on labour market participation and opportunities for younger and older workers in the East Midlands (UK). Design/methodology/approach: A statistical analysis of Labour Force Survey data was undertaken to demonstrate that health issues…

Fatigue in Younger and Older Drivers: Effectiveness of an Alertness-Maintaining Task.

Science.gov (United States)

Song, Woojin; Woon, Fu L; Doong, Alice; Persad, Carol; Tijerina, Louis; Pandit, Pooja; Cline, Carol; Giordani, Bruno

2017-09-01

The aim of this study was to examine the effects of an alertness-maintaining task (AMT) in older, fatigued drivers. Fatigue during driving increases crash risk, and previous research suggests that alertness and driving in younger adults may be improved using a secondary AMT during boring, fatigue-eliciting drives. However, the potential impact of an AMT on driving has not been investigated in older drivers whose ability to complete dual tasks has been shown to decline and therefore may be negatively affected with an AMT in driving. Younger ( n = 29) and older drivers ( n = 39) participated in a 50-minute simulated drive designed to induce fatigue, followed by four 10-minute sessions alternating between driving with and without an AMT. Younger drivers were significantly more affected by fatigue on driving performance than were older drivers but benefitted significantly from the AMT. Older drivers did not demonstrate increased driver errors with fatigue, and driving did not deteriorate significantly during participation in the AMT condition, although their speed was significantly more variable with the AMT. Consistent with earlier research, an AMT applied during fatiguing driving is effective in improving alertness and reducing driving errors in younger drivers. Importantly, older drivers were relatively unaffected by fatigue, and use of an AMT did not detrimentally affect their driving performance. These results support the potential use of an AMT as a new automotive technology to improve fatigue and promote driver safety, though the benefits of such technology may differ between different age groups.

Comparison and evaluation of dietary quality between older and younger Mexican-American women.

Science.gov (United States)

Pignotti, Giselle A P; Vega-López, Sonia; Keller, Colleen; Belyea, Michael; Ainsworth, Barbara; Nagle Williams, Allison; Records, Kathie; Coonrod, Dean; Permana, Paska

2015-10-01

To compare and evaluate the dietary quality of young and older sedentary Mexican-American women. Understanding key dietary concerns, while considering developmental transition periods and cultural relevance, can provide insight for developing appropriate nutrition interventions. Cross-sectional dietary data were collected using unannounced 24 h diet recalls to assess nutrient intake adequacy (Estimated Average Requirement cut-point method) and dietary quality (Healthy Eating Index (HEI) 2010). Mujeres en Acción and Madres para la Salud, two community-based physical activity interventions. Participants were 139 young (28 (sd 6) years) and 124 older (55 (sd 7) years) overweight/obese sedentary Mexican-American women (BMI=25·0-35·0 kg/m2) of low socio-economic status. Older women consumed less Ca, Fe, folate, empty calories and energy from carbohydrate, but more fruit, vegetables, greens and beans, and fibre than younger women (all P<0·05). Over 60 % of all participants had an intake below recommendations for fibre, Ca, vitamin E, vitamin C and folate. Both groups had low total HEI-2010 scores (62 for older and 63 for younger women; NS), with 57 % of older and 48 % of younger women classified as having a poor diet. Despite differences in nutrient requirements according to developmental transition periods (childbearing v. perimenopausal), overall, older and younger Mexican-American women generally had low-quality diets and may benefit from dietary quality improvement.

An alternative origin for extraterrestrial biomolecules from the hot and ionized photosphere of the protosolar nebula.

Science.gov (United States)

Bekaert, D. V.; Derenne, S.; Tissandier, L.; Marrocchi, Y.; Anquetil, C.; Marty, B.

2017-12-01

Organic matter (OM) synthesized from plasma experiments (so-called Nebulotron) can provide an insight into the processes of organosynthesis within the ionized gas phase of the protosolar nebula (PSN). Organic materials recovered from Nebulotron experiments have a record of success in reproducing key features of chondritic insoluble organic matter (IOM), including the aromatic/aliphatic and soluble/insoluble ratios [1], the occurrence of D/H hot and cold spots [2], spectral features as well as elementary and isotopic patterns observed in trapped noble gases [3]. However, up until now little attention has been paid to the soluble fraction of the recovered OM (SOM). In this study, a high-vacuum plasma setting was designed to produce organic condensates from a CO-N2-H2 gas mixture reminiscent of the PSN. The chemical diversity of the synthetized SOM has been investigated by gas chromatography - mass spectrometry. Our results show that a large range of biomolecules detected in meteorites and comets could have been directly synthetized from the gas phase of the PSN under high ionization rates and temperatures > 800 K. Among other molecules, urea, formamide, glycerol, hydantoin, carboxylic acids, as well as amino acid and nucleobase derivatives are reported. While photochemical processing of interstellar icy grains or asteroidal aqueous alteration are often advocated for the origin of biomolecules in extraterrestrial samples, our results suggest that biomolecule production was also effective in the hot and ionized photosphere of the PSN. Interestingly, solid-state 13C Nuclear Magnetic Resonance spectra of the Nebulotron IOM, indicates that they are very low in aromatics relative to extraterrestrial samples. Given that aromatic units in meteoritic IOM likely result from the cyclization/aromatization of aliphatic chains in the gas [1], Nebulotron-like aliphatic materials could represent the initial precursors of meteoritic OM [4]. These materials would be widespread in the

Surface biosignatures of exo-earths: remote detection of extraterrestrial life.

Science.gov (United States)

Hegde, Siddharth; Paulino-Lima, Ivan G; Kent, Ryan; Kaltenegger, Lisa; Rothschild, Lynn

2015-03-31

Exoplanet discovery has made remarkable progress, with the first rocky planets having been detected in the central star's liquid water habitable zone. The remote sensing techniques used to characterize such planets for potential habitability and life rely solely on our understanding of life on Earth. The vegetation red edge from terrestrial land plants is often used as a direct signature of life, but it occupies only a small niche in the environmental parameter space that binds life on present-day Earth and has been widespread for only about 460 My. To more fully exploit the diversity of the one example of life known, we measured the spectral characteristics of 137 microorganisms containing a range of pigments, including ones isolated from Earth's most extreme environments. Our database covers the visible and near-infrared to the short-wavelength infrared (0.35-2.5 µm) portions of the electromagnetic spectrum and is made freely available from biosignatures.astro.cornell.edu. Our results show how the reflectance properties are dominated by the absorption of light by pigments in the visible portion and by strong absorptions by the cellular water of hydration in the infrared (up to 2.5 µm) portion of the spectrum. Our spectral library provides a broader and more realistic guide based on Earth life for the search for surface features of extraterrestrial life. The library, when used as inputs for modeling disk-integrated spectra of exoplanets, in preparation for the next generation of space- and ground-based instruments, will increase the chances of detecting life.

Early social-communicative and cognitive development of younger siblings of children with autism spectrum disorders.

Science.gov (United States)

Stone, Wendy L; McMahon, Caitlin R; Yoder, Paul J; Walden, Tedra A

2007-04-01

To compare the early social-communicative development of younger siblings of children with autism spectrum disorders (ASDs) with that of younger siblings of children with typical development, using parental report and child-based measures. Group comparison. Vanderbilt University, between July 1, 2003, and July 31, 2006. Younger siblings of children with ASD (n = 64) and younger siblings of children with typical development (n = 42) between the ages of 12 and 23 months (mean, 16 months). Main Exposure Having a sibling with an ASD. Child-based measures included a cognitive assessment; an interactive screening tool assessing play, imitation, and communication; and a rating of autism symptoms. Parental report measures were an interview of social-communicative interactions and a questionnaire assessing language and communication skills. Younger siblings of children with ASD demonstrated weaker performance in nonverbal problem solving (mean difference [MD], 5.91; 95% confidence interval [CI], 2.48-9.34), directing attention (MD, 0.52; 95% CI, 0.07-0.97), understanding words (MD, 33.30; 95% CI, 3.11-63.48), understanding phrases (MD, 4.56; 95% CI, 1.85-7.27), gesture use (MD, 1.49; 95% CI, 0.51-2.47), and social-communicative interactions with parents (MD, 1.32; 95% CI, 0.27-2.37), and had increased autism symptoms (MD, 2.54; 95% CI, 1.05-4.03), relative to control siblings. A substantial minority of the ASD sibling group exhibited lower performance relative to controls. Significant correlations between child-based measures and parental reports assessing similar constructs were found (r = -0.74 to 0.53; P range, .000-.002). The weaker performance found for children in the ASD sibling group may represent early-emerging features of the broader autism phenotype, thus highlighting the importance of developmental surveillance for younger siblings.

The housing careers of younger adults and intergenerational support in Germany’s ‘society of renters’

NARCIS (Netherlands)

Lennartz, C.; Helbrecht, I.

2018-01-01

Through narrative interviews with younger adults and their parents, this paper explores how the housing transitions of younger adults, both within the rental sector and into homeownership, are shaped through intergenerational intra-family support in Germany’s society of renters. Our findings

Comparing older and younger Japanese primiparae: fatigue, depression and biomarkers of stress.

Science.gov (United States)

Mori, Emi; Maehara, Kunie; Iwata, Hiroko; Sakajo, Akiko; Tsuchiya, Miyako; Ozawa, Harumi; Morita, Akiko; Maekawa, Tomoko; Saeki, Akiko

2015-03-01

This cohort study of primiparae was conducted to answer the following questions: Do older (≧ 35 years) and younger (20-29 years) Japanese primiparous mothers differ when comparing biomarkers of stress and measures of fatigue and depression? Are there changes in fatigue, depression and stress biomarkers when comparing older and younger mothers during the postpartum period? The Postnatal Accumulated Fatigue Scale and the Edinburgh Postnatal Depression Scale were administered in a time-series method four times: shortly after birth and monthly afterwards. Assays to measure biomarkers of stress, urinary 17-ketosteroids, urinary 17-hydroxycorticosteroids and salivary chromogranin-A, were collected shortly after delivery and at 1 month postpartum in both groups and a third time in older mothers at the 4th month. Statistical testing showed very little difference in fatigue, depression or stress biomarkers between older and younger mothers shortly after birth or 1 month later. Accumulated fatigue and depression scores of older mothers were highest 1 month after delivery. Additional cohort studies are required to characterize physical/psychological well-being of older Japanese primiparae. © 2015 Wiley Publishing Asia Pty Ltd.

Body image after mastectomy: A thematic analysis of younger women's written accounts.

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Grogan, Sarah; Mechan, Jayne

2017-09-01

This study investigated younger women's body image after mastectomy. In all, 49 women, aged 29-53 years (mean age: 39 years) who had had bilateral ( n = 8) or unilateral ( n = 41) mastectomy responded to open-ended questions online. Inductive thematic analysis revealed that aesthetics were less important than survival between diagnosis and mastectomy. Following mastectomy, women negotiated new body identities. Treatment effects such as weight gain were significant concerns. However, impacts on body confidence varied, and some participants rejected mainstream body shape ideals and reported feeling proud of their scars. Implications for supporting younger women post-mastectomy, including promotion of body acceptance, are discussed.

Addressing Younger Workers’ Needs: The Promoting U through Safety and Health (PUSH Trial Outcomes

Directory of Open Access Journals (Sweden)

Diane S. Rohlman

2016-08-01

Full Text Available Most younger workers, less than 25 years old, receive no training in worker safety. We report the feasibility and outcomes of a randomized controlled trial of an electronically delivered safety and health curriculum for younger workers entitled, PUSH (Promoting U through Safety and Health. All younger workers (14–24 years old hired for summer work at a large parks and recreation organization were invited to participate in an evaluation of an online training and randomized into an intervention or control condition. Baseline and end-of-summer online instruments assessed acceptability, knowledge, and self-reported attitudes and behaviors. One-hundred and forty participants (mean age 17.9 years completed the study. The innovative training was feasible and acceptable to participants and the organization. Durable increases in safety and health knowledge were achieved by intervention workers (p < 0.001, effect size (Cohen’s d 0.4. However, self-reported safety and health attitudes did not improve with this one-time training. These results indicate the potential utility of online training for younger workers and underscore the limitations of a single training interaction to change behaviors. Interventions may need to be delivered over a longer period of time and/or include environmental components to effectively alter behavior.

Addressing Younger Workers’ Needs: The Promoting U through Safety and Health (PUSH) Trial Outcomes

Science.gov (United States)

Rohlman, Diane S.; Parish, Megan; Elliot, Diane L.; Hanson, Ginger; Perrin, Nancy

2016-01-01

Most younger workers, less than 25 years old, receive no training in worker safety. We report the feasibility and outcomes of a randomized controlled trial of an electronically delivered safety and health curriculum for younger workers entitled, PUSH (Promoting U through Safety and Health). All younger workers (14–24 years old) hired for summer work at a large parks and recreation organization were invited to participate in an evaluation of an online training and randomized into an intervention or control condition. Baseline and end-of-summer online instruments assessed acceptability, knowledge, and self-reported attitudes and behaviors. One-hundred and forty participants (mean age 17.9 years) completed the study. The innovative training was feasible and acceptable to participants and the organization. Durable increases in safety and health knowledge were achieved by intervention workers (p < 0.001, effect size (Cohen’s d) 0.4). However, self-reported safety and health attitudes did not improve with this one-time training. These results indicate the potential utility of online training for younger workers and underscore the limitations of a single training interaction to change behaviors. Interventions may need to be delivered over a longer period of time and/or include environmental components to effectively alter behavior. PMID:27517968

Filtering and storage working memory networks in younger and older age.

Science.gov (United States)

Vellage, Anne-Katrin; Becke, Andreas; Strumpf, Hendrik; Baier, Bernhard; Schönfeld, Mircea Ariel; Hopf, Jens-Max; Müller, Notger G

2016-11-01

Working memory (WM) is a multi-component model that among others involves the two processes of filtering and storage. The first reflects the necessity to inhibit irrelevant information from entering memory, whereas the latter refers to the active maintenance of object representations in memory. In this study, we aimed at a) redefining the neuronal networks sustaining filtering and storage within visual working memory by avoiding shortcomings of prior studies, and b) assessing age-related changes in these networks. We designed a new paradigm that strictly controlled for perceptual load by presenting the same number of stimuli in each of three conditions. We calculated fMRI contrasts between a baseline condition (low filter and low storage load) and conditions that posed high demands on filtering and storage, respectively, in large samples of younger ( n  = 40) and elder ( n  = 38) participants. Our approach of comparing contrasts between groups revealed more extensive filter and storage WM networks than previous studies. In the younger group, filtering involved the bilateral insulae, the right occipital cortex, the right brainstem, and the right cerebellum. In the elder group, filtering was associated with the bilateral insulae, right precuneus, and bilateral ventromedial prefrontal cortex. An extensive neuronal network was also found during storage of information in the bilateral posterior parietal cortex, the left ventromedial prefrontal cortex, and the right precuneus in the younger participants. In addition to these brain regions, elder participants recruited the bilateral ventral prefrontal cortex, the superior, middle and inferior and temporal cortex, the left cingulum and the bilateral parahippocampal cortex. In general, elder participants recruited more brain regions in comparison to younger participants to reach similar accuracy levels. Furthermore, in elder participants one brain region emerged in both contrasts, namely the left ventromedial prefrontal

Localized prostate cancer in elderly patients. Outcome after radiation therapy compared to matched younger patients

International Nuclear Information System (INIS)

Huguenin, P.U.; Bitterli, M.; Luetolf, U.M.; Glanzmann, C.; Bernhard, J.

1999-01-01

Purpose: To detect a difference in outcome (disease-specific survival, local tumor progression, late toxicity, quality of life) after curative radiotherapy for localized prostate cancer in elderly as compared to younger patients. Patients and methods: In a retrospective analysis 59 elderly patients (>74 years old) were matched 1:2 with younger patients from the data base according to tumor stage, grading, pre-treatment PSA values and year of radiotherapy. Surviving patients were contacted to fill in a validated questionnaire for quality of life measurement (EORTC QLQ-C30). Median follow-up for elderly and younger patients was 5.2 and 4.5 years, respectively. Results: Overall survival at 5 years was 66% for the elderly and 80% for younger patients. Intercurrent deaths were observed more frequently in the elderly population. There was no age-specific difference in disease-specific survival (78% vs 82%), late toxicity or quality of life. Clinically meaningful local tumor progression was observed in 15% and 14%, respectively, corresponding to data from the literature following hormonal ablation. Conclusions: There is no obvious difference in outcome including disease-specific survival, late toxicity and quality of life in elderly patients, compared to a matched younger population. A clinically meaningful local tumor progression following radiotherapy or hormonal ablation only is rare. Local radiotherapy or, alternatively, hormonal ablation is recommended to preserve local progression-free survival in elderly patients except for very early stage of disease (i.e. T1 G1-2 M0). (orig.) [de

Expectations of younger patients concerning activities after knee arthroplasty: are we asking the right questions?

Science.gov (United States)

Witjes, Suzanne; van Geenen, Rutger C I; Koenraadt, Koen L M; van der Hart, Cor P; Blankevoort, Leendert; Kerkhoffs, Gino M M J; Kuijer, P Paul F M

2017-02-01

Indications for total and unicondylar knee arthroplasty (KA) have expanded to younger patients, in which Patient-Reported Outcome Measures (PROMs) often show ceiling effects. This might be due to higher expectations. Our aims were to explore expectations of younger patients concerning activities in daily life, work and leisure time after KA and to assess to what extent PROMs meet and evaluate these activities of importance. Focus groups were performed among osteoarthritis (OA) patients leisure time after KA. Additionally, 28 activities of daily life, 17 of work and 27 of leisure time were depicted from seven PROMS, which were rated on importance, frequency and bother. A total score, representing motivation for surgery, was also calculated. Data saturation was reached after six focus groups including 37 patients. Younger OA patients expect to perform better on 16 activities after KA, including high-impact leisure time activities. From the PROMs, daily life and work activities were rated high in both importance and motivation for surgery, but for leisure time activities importance varied highly between patients. All seven PROMs score activities of importance, but no single PROM incorporates all activities rated important. Younger patients expect to perform better on many activities of daily life, work and leisure time after KA, and often at demanding levels. To measure outcomes of younger patients, we suggest using PROMs that include work and leisure time activities besides daily life activities, in which preferably scored activities can be individualized.

Laboratory Studies on the Formation of Carbon-Bearing Molecules in Extraterrestrial Environments: From the Gas Phase to the Solid State

Science.gov (United States)

Jamieson, C. S.; Guo, Y.; Gu, X.; Zhang, F.; Bennett, C. J.; Kaiser, R. I.

2006-01-01

A detailed knowledge of the formation of carbon-bearing molecules in interstellar ices and in the gas phase of the interstellar medium is of paramount interest to understand the astrochemical evolution of extraterrestrial environments (1). This research also holds strong implications to comprehend the chemical processing of Solar System environments such as icy planets and their moons together with the atmospheres of planets and their satellites (2). Since the present composition of each interstellar and Solar System environment reflects the matter from which it was formed and the processes which have changed the chemical nature since the origin (solar wind, planetary magnetospheres, cosmic ray exposure, photolysis, chemical reactions), a detailed investigation of the physicochemical mechanisms altering the pristine environment is of paramount importance to grasp the contemporary composition. Once these underlying processes have been unraveled, we can identify those molecules, which belonged to the nascent setting, distinguish molecular species synthesized in a later stage, and predict the imminent chemical evolution of, for instance, molecular clouds. Laboratory experiments under controlled physicochemical conditions (temperature, pressure, chemical composition, high energy components) present ideal tools for simulating the chemical evolution of interstellar and Solar System environments. Here, laboratory experiments can predict where and how (reaction mechanisms; chemicals necessary) in extraterrestrial environments and in the interstellar medium complex, carbon bearing molecules can be formed on interstellar grains and in the gas phase. This paper overviews the experimental setups utilized in our laboratory to mimic the chemical processing of gas phase and solid state (ices) environments. These are a crossed molecular beams machine (3) and a surface scattering setup (4). We also present typical results of each setup (formation of amino acids, aldehydes, epoxides

Incidence of Cancers of the Lower Stomach Increasing among Younger Americans

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... News & Events Cancer Currents Blog Cancer Currents Blog Incidence of Cancers of the Lower Stomach Increasing among ... younger individuals, she added. Risk Factors and Shifting Incidence Rates Two of the main causes of noncardia ...

(2008) SWJ:121-126 Evolutionary Trend of The Jarawa Younger ...

African Journals Online (AJOL)

Dr. Ahmed

2008) SWJ:121-126. Evolutionary Trend of The Jarawa Younger Granite. TABLE 1. CHEMICAL COMPOSITION OF HORNBLENDE PORPHYRY GRANITES. Sample. No. Oxide (%). K2O CaO MgO FeO Fe2O3. AL2O3 Na2O PbO. JA-HP.

Variability in reaction time performance of younger and older adults.

Science.gov (United States)

Hultsch, David F; MacDonald, Stuart W S; Dixon, Roger A

2002-03-01

Age differences in three basic types of variability were examined: variability between persons (diversity), variability within persons across tasks (dispersion), and variability within persons across time (inconsistency). Measures of variability were based on latency performance from four measures of reaction time (RT) performed by a total of 99 younger adults (ages 17--36 years) and 763 older adults (ages 54--94 years). Results indicated that all three types of variability were greater in older compared with younger participants even when group differences in speed were statistically controlled. Quantile-quantile plots showed age and task differences in the shape of the inconsistency distributions. Measures of within-person variability (dispersion and inconsistency) were positively correlated. Individual differences in RT inconsistency correlated negatively with level of performance on measures of perceptual speed, working memory, episodic memory, and crystallized abilities. Partial set correlation analyses indicated that inconsistency predicted cognitive performance independent of level of performance. The results indicate that variability of performance is an important indicator of cognitive functioning and aging.

Older adults catch up to younger adults on a learning and memory task that involves collaborative social interaction.

Science.gov (United States)

Derksen, B J; Duff, M C; Weldon, K; Zhang, J; Zamba, K D; Tranel, D; Denburg, N L

2015-01-01

Learning and memory abilities tend to decline as people age. The current study examines the question of whether a learning situation that emphasises collaborative social interaction might help older persons overcome age-related learning and memory changes and thus perform similarly to younger persons. Younger and Older participants (n = 34 in each group) completed the Barrier Task (BT), a game-like social interaction where partners work together to develop labels for a set of abstract tangrams. Participants were also administered standard clinical neuropsychological measures of memory, on which the Older group showed expected inferiority to the Younger group. On the BT, the Older group performed less well than the Younger group early on, but as the task progressed, the performance of the Older group caught up and became statistically indistinguishable from that of the Younger group. These results can be taken to suggest that a learning milieu characterised by collaborative social interaction can attenuate some of the typical memory disadvantages associated with being older.

Burden of invasive bacterial disease among children younger than 5 ...

African Journals Online (AJOL)

Background: Haemophilus influenzae b (Hib), pneumococcus and meningococcus are responsible for high mortality and morbidity in children younger than 5 years of age worldwide. Hib containing vaccine was introduced in July 2008 in Togo; and baseline data are available on bacterial meningitis prior to PCV13 vaccine ...

Evaluating authentication options for mobile health applications in younger and older adults

Science.gov (United States)

Khan, Hassan; Hengartner, Urs; Ong, Stephanie; Logan, Alexander G.; Vogel, Daniel; Gebotys, Robert; Yang, Jilan

2018-01-01

Objective Apps promoting patient self-management may improve health outcomes. However, methods to secure stored information on mobile devices may adversely affect usability. We tested the reliability and usability of common user authentication techniques in younger and older adults. Methodology Usability testing was conducted in two age groups, 18 to 30 years and 50 years and older. After completing a demographic questionnaire, each participant tested four authentication options in random order: four-digit personal identification number (PIN), graphical password (GRAPHICAL), Android pattern-lock (PATTERN), and a swipe-style Android fingerprint scanner (FINGERPRINT). Participants rated each option using the Systems Usability Scale (SUS). Results A total of 59 older and 43 younger participants completed the study. Overall, PATTERN was the fastest option (3.44s), and PIN had the fewest errors per attempt (0.02). Participants were able to login using PIN, PATTERN, and GRAPHICAL at least 98% of the time. FINGERPRINT was the slowest (26.97s), had an average of 1.46 errors per attempt, and had a successful login rate of 85%. Overall, PIN and PATTERN had higher SUS scores than FINGERPRINT and GRAPHICAL. Compared to younger participants, older participants were also less likely to find PATTERN to be tiring, annoying or time consuming and less likely to consider PIN to be time consuming. Younger participants were more likely to rate GRAPHICAL as annoying, time consuming and tiring than older participants. Conclusions On mobile devices, PIN and pattern-lock outperformed graphical passwords and swipe-style fingerprints. All participants took longer to authenticate using the swipe-style fingerprint compared to other options. Older participants also took two to three seconds longer to authenticate using the PIN, pattern and graphical passwords though this did not appear to affect perceived usability. PMID:29300736

Evaluating authentication options for mobile health applications in younger and older adults.

Directory of Open Access Journals (Sweden)

Kelly Grindrod

Full Text Available Apps promoting patient self-management may improve health outcomes. However, methods to secure stored information on mobile devices may adversely affect usability. We tested the reliability and usability of common user authentication techniques in younger and older adults.Usability testing was conducted in two age groups, 18 to 30 years and 50 years and older. After completing a demographic questionnaire, each participant tested four authentication options in random order: four-digit personal identification number (PIN, graphical password (GRAPHICAL, Android pattern-lock (PATTERN, and a swipe-style Android fingerprint scanner (FINGERPRINT. Participants rated each option using the Systems Usability Scale (SUS.A total of 59 older and 43 younger participants completed the study. Overall, PATTERN was the fastest option (3.44s, and PIN had the fewest errors per attempt (0.02. Participants were able to login using PIN, PATTERN, and GRAPHICAL at least 98% of the time. FINGERPRINT was the slowest (26.97s, had an average of 1.46 errors per attempt, and had a successful login rate of 85%. Overall, PIN and PATTERN had higher SUS scores than FINGERPRINT and GRAPHICAL. Compared to younger participants, older participants were also less likely to find PATTERN to be tiring, annoying or time consuming and less likely to consider PIN to be time consuming. Younger participants were more likely to rate GRAPHICAL as annoying, time consuming and tiring than older participants.On mobile devices, PIN and pattern-lock outperformed graphical passwords and swipe-style fingerprints. All participants took longer to authenticate using the swipe-style fingerprint compared to other options. Older participants also took two to three seconds longer to authenticate using the PIN, pattern and graphical passwords though this did not appear to affect perceived usability.

Evaluating authentication options for mobile health applications in younger and older adults.

Science.gov (United States)

Grindrod, Kelly; Khan, Hassan; Hengartner, Urs; Ong, Stephanie; Logan, Alexander G; Vogel, Daniel; Gebotys, Robert; Yang, Jilan

2018-01-01

Apps promoting patient self-management may improve health outcomes. However, methods to secure stored information on mobile devices may adversely affect usability. We tested the reliability and usability of common user authentication techniques in younger and older adults. Usability testing was conducted in two age groups, 18 to 30 years and 50 years and older. After completing a demographic questionnaire, each participant tested four authentication options in random order: four-digit personal identification number (PIN), graphical password (GRAPHICAL), Android pattern-lock (PATTERN), and a swipe-style Android fingerprint scanner (FINGERPRINT). Participants rated each option using the Systems Usability Scale (SUS). A total of 59 older and 43 younger participants completed the study. Overall, PATTERN was the fastest option (3.44s), and PIN had the fewest errors per attempt (0.02). Participants were able to login using PIN, PATTERN, and GRAPHICAL at least 98% of the time. FINGERPRINT was the slowest (26.97s), had an average of 1.46 errors per attempt, and had a successful login rate of 85%. Overall, PIN and PATTERN had higher SUS scores than FINGERPRINT and GRAPHICAL. Compared to younger participants, older participants were also less likely to find PATTERN to be tiring, annoying or time consuming and less likely to consider PIN to be time consuming. Younger participants were more likely to rate GRAPHICAL as annoying, time consuming and tiring than older participants. On mobile devices, PIN and pattern-lock outperformed graphical passwords and swipe-style fingerprints. All participants took longer to authenticate using the swipe-style fingerprint compared to other options. Older participants also took two to three seconds longer to authenticate using the PIN, pattern and graphical passwords though this did not appear to affect perceived usability.

Do Correlates of Pain-Related Stoicism and Cautiousness Differ in Younger and Older People With Advanced Cancer?

Science.gov (United States)

Mah, Kenneth; Tran, Kim T; Gauthier, Lynn R; Rodin, Gary; Zimmermann, Camilla; Warr, David; Librach, S Lawrence; Moore, Malcolm; Shepherd, Frances A; Gagliese, Lucia

2018-03-01

Age differences are not evident in pain-related stoicism and cautiousness in people with cancer pain. Little is known about the factors associated with these pain-related attitudes or age-related patterns in these associations. The present cross-sectional study investigated the biopsychosocial correlates of the attitudes in younger and older patients with advanced cancer. Pain-related stoicism (fortitude, concealment, superiority) and cautiousness (self-doubt, reluctance) were assessed using the Pain Attitudes Questionnaire-Revised (PAQ-R). Participants, 155 younger (younger than 60 years old) and 114 older (60 years old or older) patients with advanced cancer completed the PAQ-R and measures of sociodemographic and medical characteristics, pain intensity, cognitive-affective pain-related responses, physical functioning, psychological distress and well-being, and psychosocial functioning. Backwards regression analyses identified correlates for each PAQ-R factor separately for younger and older patients. Activity engagement was a frequent correlate, but its relationship with concealment was the only association common to both age groups. Younger and older patients exhibited different avoidance-related constructs suggesting relational challenges in the former group (avoidant attachment) and intrapersonal fear in the latter (cognitive avoidance). Medical correlates also showed age differences: younger patients showed symptom-focused correlates, whereas older patients showed aging-related correlates. Findings support a biopsychosocial framework of cancer-pain adaptation incorporating a lifespan-developmental perspective. To our knowledge, this article is the first to identify biopsychosocial correlates of stoic and cautious attitudes toward cancer pain in younger and older patients with advanced cancer. Findings highlight possible age-related motivations for greater pain-related stoicism or cautiousness and can potentially inform interventions addressing challenges in

Screening for Dyslipidemia in Younger Adults: A Systematic Review for the U.S. Preventive Services Task Force.

Science.gov (United States)

Chou, Roger; Dana, Tracy; Blazina, Ian; Daeges, Monica; Bougatsos, Christina; Jeanne, Thomas L

2016-10-18

Dyslipidemia may occur in younger adults (defined as persons aged 21 to 39 years) and is an important risk factor for cardiovascular disease. Screening might identify younger adults with asymptomatic dyslipidemia who may benefit from lipid-lowering therapies. To update the 2008 U.S. Preventive Services Task Force review on dyslipidemia screening in younger adults. The Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, and MEDLINE through May 2016, and reference lists. Randomized, controlled trials; cohort studies; and case-control studies on screening for or treatment of asymptomatic dyslipidemia in adults aged 21 to 39 years. The plan was for 1 investigator to abstract data and a second to check their accuracy, and for 2 investigators to independently assess study quality; however, no studies met the inclusion criteria. No study evaluated the effects of lipid screening versus no screening, treatment versus no treatment, or delayed versus earlier treatment on clinical outcomes in younger adults. In addition, no study evaluated the diagnostic yield of alternative screening strategies (such as targeted screening of persons with a family history of hyperlipidemia vs. general screening) in younger adults. No direct relevant evidence. Direct evidence on the benefits and harms of screening for or treatment of dyslipidemia in younger adults remains unavailable. Estimating the potential effects of screening for dyslipidemia in this population requires extrapolation from studies performed in older adults. Agency for Healthcare Research and Quality.

Teaching Planetary Science as Part of the Search for Extraterrestrial Intelligence (SETI)

Science.gov (United States)

Margot, Jean-Luc; Greenberg, Adam H.

2017-10-01

In Spring 2016 and 2017, UCLA offered a course titled "EPSS C179/279 - Search for Extraterrestrial Intelligence: Theory and Applications". The course is designed for advanced undergraduate students and graduate students in the science, technical, engineering, and mathematical fields. Each year, students designed an observing sequence for the Green Bank telescope, observed known planetary systems remotely, wrote a sophisticated and modular data processing pipeline, analyzed the data, and presented their results. In 2016, 15 students participated in the course (9U, 5G; 11M, 3F) and observed 14 planetary systems in the Kepler field. In 2017, 17 students participated (15U, 2G; 10M, 7F) and observed 10 planetary systems in the Kepler field, TRAPPIST-1, and LHS 1140. In order to select suitable targets, students learned about planetary systems, planetary habitability, and planetary dynamics. In addition to planetary science fundamentals, students learned radio astronomy fundamentals, collaborative software development, signal processing techniques, and statistics. Evaluations indicate that the course is challenging but that students are eager to learn because of the engrossing nature of SETI. Students particularly value the teamwork approach, the observing experience, and working with their own data. The next offering of the course will be in Spring 2018. Additional information about our SETI work is available at seti.ucla.edu.

The effects of value on context-item associative memory in younger and older adults.

Science.gov (United States)

Hennessee, Joseph P; Knowlton, Barbara J; Castel, Alan D

2018-02-01

Valuable items are often remembered better than items that are less valuable by both older and younger adults, but older adults typically show deficits in binding. Here, we examine whether value affects the quality of recognition memory and the binding of incidental details to valuable items. In Experiment 1, participants learned English words each associated with a point-value they earned for correct recognition with the goal of maximizing their score. In Experiment 2, value was manipulated by presenting items that were either congruent or incongruent with an imagined state of physiological need (e.g., hunger). In Experiment 1, point-value was associated with enhanced recollection in both age groups. Memory for the color associated with the word was in fact reduced for high-value recollected items compared with low-value recollected items, suggesting value selectively enhances binding of task-relevant details. In Experiment 2, memory for learned images was enhanced by value in both age groups. However, value differentially enhanced binding of an imagined context to the item in younger and older adults, with a strong trend for increased binding in younger adults only. These findings suggest that value enhances episodic encoding in both older and younger adults but that binding of associated details may be reduced for valuable items compared to less valuable items, particularly in older adults. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Pollen-based evidence of extreme drought during the last Glacial (32.6-9.0 ka) in coastal southern California

Science.gov (United States)

Heusser, Linda E.; Kirby, Matthew E.; Nichols, Jonathan E.

2015-10-01

High resolution pollen analyses of sediment core LEDC10-1 from Lake Elsinore yield the first well-dated, terrestrial record of sub-centennial-scale ecologic change in coastal southern California between ˜32 and 9 ka. In the Lake Elsinore watershed, the initial, mesic montane conifer forests dominated by Pinus, and Cupressaceae with trace amounts of Abies and Picea were replaced by a sequence of multiple, extended severe mega-droughts between ˜27.5 and ˜25.5 ka, in which halophytic and xerophytic herbs and shrubs occupied an ephemeral lake. This prolonged and extended dry interval, which corresponds with warm waters offshore, imply strengthening of the North Pacific High and persistent below-average winter precipitation. The subsequent, contrasting monotonic occurrence of montane conifers reflects little variation in cold, mesic climate until ˜15 ka. Postglacial development of Quercus woodland and chaparral mark the return to more xeric, warmer conditions at this time. A brief reversal at ˜13.1-˜12.1 ka, as reflected by an expansion of Pinus, is correlative with the Younger Dryas and interrupts development of warm, postglacial climate. Subsequent gradual expansion of xeric vegetation post - Younger Dryas denotes the establishment of a winter hydroclimate regime in coastal southern California that is more similar to modern conditions. Pollen-based reconstructions of temperature and precipitation at Lake Elsinore are generally correlative with pollen-based paleoclimatic reconstructions and foraminifera-based sea surface temperatures from Santa Barbara Basin in marine core ODP 893. The conspicuous absence of the ˜27.5-˜25.5 ka glacial "mega-drought" in the Santa Barbara Basin pollen record highlights the sensitivity of Lake Elsinore to hydroclimate change, and thus, the importance of this new record that indicates that mega-drought can occur during the full glacial when climatic boundary conditions and forcings differed substantially from the present.

Post-glacial flooding of the Bering Land Bridge dated to 11 cal ka BP based on new geophysical and sediment records

Directory of Open Access Journals (Sweden)

M. Jakobsson

2017-08-01

Full Text Available The Bering Strait connects the Arctic and Pacific oceans and separates the North American and Asian landmasses. The presently shallow ( ∼  53 m strait was exposed during the sea level lowstand of the last glacial period, which permitted human migration across a land bridge today referred to as the Bering Land Bridge. Proxy studies (stable isotope composition of foraminifera, whale migration into the Arctic Ocean, mollusc and insect fossils and paleobotanical data have suggested a range of ages for the Bering Strait reopening, mainly falling within the Younger Dryas stadial (12.9–11.7 cal ka BP. Here we provide new information on the deglacial and post-glacial evolution of the Arctic–Pacific connection through the Bering Strait based on analyses of geological and geophysical data from Herald Canyon, located north of the Bering Strait on the Chukchi Sea shelf region in the western Arctic Ocean. Our results suggest an initial opening at about 11 cal ka BP in the earliest Holocene, which is later than in several previous studies. Our key evidence is based on a well-dated core from Herald Canyon, in which a shift from a near-shore environment to a Pacific-influenced open marine setting at around 11 cal ka BP is observed. The shift corresponds to meltwater pulse 1b (MWP1b and is interpreted to signify relatively rapid breaching of the Bering Strait and the submergence of the large Bering Land Bridge. Although the precise rates of sea level rise cannot be quantified, our new results suggest that the late deglacial sea level rise was rapid and occurred after the end of the Younger Dryas stadial.

Climatically-controlled siliceous productivity in the eastern Gulf of Guinea during the last 40 000 yr

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X. Crosta

2012-03-01

Full Text Available Opal content and diatom assemblages were analysed in core GeoB4905-4 to reconstruct siliceous productivity changes in the eastern Gulf of Guinea during the last 40 000 yr. Opal and total diatom accumulation rates presented low values over the considered period, except during the Last Glacial Maximum and between 15 000 calendar years Before Present (15 cal. ka BP and 5.5 cal. ka BP, the so-called African Humid Period, when accumulation rates of brackish and freshwater diatoms at the core site were highest. Conversely, accumulation rates of windblown diatoms exhibited an opposite pattern with higher values before and after the African Humid Period and greatest values during Heinrich Events, the Younger Dryas and since 5.5 cal. ka BP.

Our results demonstrate that siliceous productivity in the eastern Gulf of Guinea was directly driven by the nutrient load from local rivers, whose discharges were forced by precipitation changes over western Equatorial Africa and/or modification of the fluvio-deltaic systems forced by sea level changes. Precipitation in this region is controlled by the West African monsoon which is, in turn, partly dependent on the presence and intensity of the Atlantic Cold Tongue (ACT. Our results therefore suggest that the ACT was weakened, warmer trade winds were less vigorous, and cloud convection and precipitation were greater during the AHP though centennial-to-millennial timescale dry events were observed at ∼10 cal. ka BP, ∼8.5 cal. ka BP and ∼6 cal. ka BP. Conversely, the ACT was more intense, trade winds were more vigorous and African climate was more arid during H1, the Younger Dryas and after 5.5 cal. ka BP into the present.

Timing of Pleistocene glaciations in the High Atlas, Morocco: New 10Be and 36Cl exposure ages

Science.gov (United States)

Hughes, Philip D.; Fink, David; Rodés, Ángel; Fenton, Cassandra R.; Fujioka, Toshiyuki

2018-01-01

This paper presents data from 42 new samples yielding Late Pleistocene cosmogenic 10Be and 36Cl exposure ages of moraine boulders across a series of glaciated valleys in the Toubkal Massif (4167 m a.s.l.), High Atlas, Morocco. This represents the first comprehensive Pleistocene glacial chronology in North Africa and one of the largest datasets from the Mediterranean region. The timing of these glacier advances has major implications for understanding the influence of Atlantic depressions on moisture supply to North Africa and the Mediterranean basin during the Pleistocene. The oldest and lowest moraines which span elevations from ∼1900 to 2400 m a.s.l. indicate that the maximum glacier advance occurred from MIS 5 to 3 with a combined mean 10Be and 36Cl age of 50.2 ± 19.5 ka (1 SD; n = 12, 7 outliers). The next moraine units up-valley at higher elevations (∼2200-2600 m a.s.l.) yielded exposure ages close to the global Last Glacial Maximum (LGM) with a combined mean 10Be and 36Cl age of 22.0 ± 4.9 ka (1 SD; n = 9, 7 outliers). The youngest exposure ages are from moraines that were emplaced during the Younger Dryas with a combined mean 10Be and 36Cl age of 12.3 ± 0.9 ka (1 SD; n = 7, no outliers) and are found in cirques at the highest elevations ranging from ∼2900 to 3300 m a.s.l. From moraines predating the Younger Dryas, a large number of young outliers are spread evenly between 6 and 13 ka suggesting a continuing process of exhumation or repositioning of boulders during the early to mid-Holocene. This attests to active seismic processes and possibly intense erosion during this period.

Extent, timing, and climatic significance of latest Pleistocene and Holocene glaciation in the Sierra Nevada, California

Energy Technology Data Exchange (ETDEWEB)

Clark, Douglas Howe [Univ. of Washington, Seattle, WA (United States)

1995-01-01

Despite more than a century of study, scant attention has been paid to the glacial record in the northern end of the Sierra Nevada, and to the smaller moraines deposited after the retreat of the Tioga (last glacial maximum) glaciers. Equilibrium-line altitude (ELA) estimates of the ice fields indicate that the Tioga ELA gradients there are consistent with similar estimates for the southern half of the range, and with an intensification of the modern temperature/precipitation pattern in the region. The Recess Peak advance has traditionally been considered to be mid-Neoglacial age, about 2--3,000 yr B.P., on the basis of relative weathering estimates. Sediment cores of lakes dammed behind moraines correlative with Recess Peak in four widely spaced sites yields a series of high-resolution AMS radiocarbon dates which demonstrate that Recess Peak glaciers retreated before ~13,100 cal yr B.P.. This minimum limiting age indicates that the advance predates the North Atlantic Younger Dryas cooling. It also implies that there have been no advances larger than the Matthes in the roughly 12,000 year interval between it and the Recess Peak advance. This finding casts doubt on several recent studies that claim Younger Dryas glacier advances in western North America. The 13,100 cal yr B.P. date is also a minimum age for deglaciation of the sample sites used to calibrate the in situ production rates of cosmogenic ¹⁰Be and ²⁶Al. The discrepancy between this age and the 11,000 cal yr B.P. exposure age assumed in the original calibration introduces a large (> 19%) potential error in late-Pleistocene exposure ages calculated using these production rates.

Post-glacial flooding of the Bering Land Bridge dated to 11 cal ka BP based on new geophysical and sediment records

Science.gov (United States)

Jakobsson, Martin; Pearce, Christof; Cronin, Thomas M.; Backman, Jan; Anderson, Leif G.; Barrientos, Natalia; Bjork, Goran; Coxhall, Helen; de Boer, Agatha; Mayer, Larry; Morth, Carl-Magnus; Nilsson, Johan; Rattray, Jayne; Sranne, Christian; Semiletov, Igor; O'Regan, Matt

2017-01-01

The Bering Strait connects the Arctic and Pacific oceans and separates the North American and Asian landmasses. The presently shallow ( ∼  53 m) strait was exposed during the sea level lowstand of the last glacial period, which permitted human migration across a land bridge today referred to as the Bering Land Bridge. Proxy studies (stable isotope composition of foraminifera, whale migration into the Arctic Ocean, mollusc and insect fossils and paleobotanical data) have suggested a range of ages for the Bering Strait reopening, mainly falling within the Younger Dryas stadial (12.9–11.7 cal ka BP). Here we provide new information on the deglacial and post-glacial evolution of the Arctic–Pacific connection through the Bering Strait based on analyses of geological and geophysical data from Herald Canyon, located north of the Bering Strait on the Chukchi Sea shelf region in the western Arctic Ocean. Our results suggest an initial opening at about 11 cal ka BP in the earliest Holocene, which is later than in several previous studies. Our key evidence is based on a well-dated core from Herald Canyon, in which a shift from a near-shore environment to a Pacific-influenced open marine setting at around 11 cal ka BP is observed. The shift corresponds to meltwater pulse 1b (MWP1b) and is interpreted to signify relatively rapid breaching of the Bering Strait and the submergence of the large Bering Land Bridge. Although the precise rates of sea level rise cannot be quantified, our new results suggest that the late deglacial sea level rise was rapid and occurred after the end of the Younger Dryas stadial.

The correlation between a passion for computer games and the school performance of younger schoolchildren.

Directory of Open Access Journals (Sweden)

Maliy D.V.

2015-07-01

Full Text Available Today computer games occupy a significant place in children’s lives and fundamentally affect the process of the formation and development of their personalities. A number of present-day researchers assert that computer games have a developmental effect on players. Others share the point of view that computer games have negative effects on the cognitive and emotional spheres of a child and claim that children with low self-esteem who neglect their schoolwork and have difficulties in communication are particularly passionate about computer games. This article reviews theoretical and experimental pedagogical and psychological studies of the nature of the correlation between a passion for computer games and the school performance of younger schoolchildren. Our analysis of foreign and Russian psychology studies regarding the problem of playing activities mediated by information and computer technologies allowed us to single out the main criteria for children’s passion for computer games and school performance. This article presents the results of a pilot study of the nature of the correlation between a passion for computer games and the school performance of younger schoolchildren. The research involved 32 pupils (12 girls and 20 boys aged 10-11 years in the 4th grade. The general hypothesis was that there are divergent correlations between the passion of younger schoolchildren for computer games and their school performance. A questionnaire survey administered to the pupils allowed us to obtain information about the amount of time they devoted to computer games, their preferences for computer-game genres, and the extent of their passion for games. To determine the level of school performance we analyzed class registers. To establish the correlation between a passion for computer games and the school performance of younger schoolchildren, as well as to determine the effect of a passion for computer games on the personal qualities of the children

Atomoxetine Treatment for ADHD: Younger Adults Compared with Older Adults

Science.gov (United States)

Durell, Todd; Adler, Lenard; Wilens, Timothy; Paczkowski, Martin; Schuh, Kory

2010-01-01

Objective: Atomoxetine is a nonstimulant medication for treating child, adolescent, and adult ADHD. This meta-analysis compared the effects in younger and older adults. Method: A post hoc analysis was conducted using data from two double-blind, placebo-controlled clinical trials. Data from patients aged 18-25 years were compared with data from…

Targeted breast cancer screening in women younger than 40: results from a statewide program.

Science.gov (United States)

Sarff, MaryClare; Schmidt, Katherine; Vetto, John T

2008-05-01

Our state Breast and Cervical Cancer Program (BCCP) has previously reported a paucity of data supporting breast screening for asymptomatic women younger than 40 (cancer detection rate of .25% per screening-year). In partnership with the local Affiliate of the Susan G. Komen for the Cure Foundation, we began a targeted "screening" program to evaluate women younger than 40 referred for symptoms or other concerns. Retrospective data review of program results, including demographics, symptoms, evaluations performed, and outcomes. A total of 176 women, ages 16 to 39 years, were referred to the BCCP/Komen program. Of the women with documented presenting symptoms, the most common was breast lump (81%). Evaluation triggered 75 surgical referrals and 69 biopsies, yielding 16 cancers (a biopsy positive rate of 23% and overall cancer detection rate from the program of 9%). For women younger than age 40, targeted breast cancer screening is a more efficient utilization of screening resources, with a higher cancer detection rate than asymptomatic screening.

Ice stratigraphy at the Pakitsoq ice margin, West Greenland, derived from gas records

DEFF Research Database (Denmark)

Schaefer, H.; Petrenko, V. V.; Brook, E. J.

2009-01-01

at Pakitsoq. Sections containing ice from every distinct climatic interval during Termination I, including Last Glacial Maximum, Bolling/Allerod, Younger Dryas and the early Holocene, are identified. In the early Holocene, we find evidence for climatic fluctuations similar to signals found in deep ice cores...... from Greenland. A second glacial-interglacial transition exposed at the extreme margin of the ice is identified as another outcrop of Termination I (rather than the onset of the Eemian interglacial as postulated in earlier work). Consequently, the main structural feature at Pakitsoq is a large......-scale anticline with accordion-type folding in both exposed sequences of the glacial-Holocene transition, leading to multiple layer duplications and age reversals....

Applying a workbook at Aikido lessons when teaching younger pupils

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Vlasova O. P.

2016-07-01

Full Text Available the article is devoted to creating the structure and the contents of a workbook for the first year children learning Aikido. The results prove the effectiveness of using the workbook: children learn the material successfully, younger pupils get enough theoretical and practical Aikido skills during the course of this martial art.

Memory Dynamics and Decision Making in Younger and Older Adults

Science.gov (United States)

Lechuga, M. Teresa; Gomez-Ariza, Carlos J.; Iglesias-Parro, Sergio; Pelegrina, Santiago

2012-01-01

The main aim of this research was to study whether memory dynamics influence older people's choices to the same extent as younger's ones. To do so, we adapted the retrieval-practice paradigm to produce variations in memory accessibility of information on which decisions were made later. Based on previous results, we expected to observe…

Younger and Sicker: Comparing Micronesians to Other Ethnicities in Hawaii.

Science.gov (United States)

Hagiwara, Megan Kiyomi Inada; Miyamura, Jill; Yamada, Seiji; Sentell, Tetine

2016-03-01

We compared the age at admission and the severity of illness of hospitalized Micronesians with 3 other racial/ethnic groups in Hawaii. With Hawaii Health Information Corporation inpatient data, we determined the age at admission and the severity of illness for 162,152 adult, non-pregnancy-related hospital discharges in Hawaii from 2010 to 2012. We performed multivariable linear regression analyses within major disease categories by racial/ethnic group. We created disease categories with all patient refined-diagnosis related groups. Hospitalized Micronesians were significantly younger at admission than were comparison racial/ethnic groups across all patient refined-diagnosis related group categories. The severity of illness for Micronesians was significantly higher than was that of all comparison racial/ethnic groups for cardiac and infectious diseases, higher than was that of Whites and Japanese for cancer and endocrine hospitalizations, and higher than was that of Native Hawaiians for substance abuse hospitalizations. Micronesians were hospitalized significantly younger and often sicker than were comparison populations. Our results will be useful to researchers, state governments, and hospitals, providers, and health systems for this vulnerable group.

Expression of emotions related to the experience of cancer in younger and older Arab breast cancer survivors.

Science.gov (United States)

Goldblatt, Hadass; Cohen, Miri; Azaiza, Faisal

2016-12-01

Researchers have suggested that older adults express less negative emotions. Yet, emotional expression patterns in older and younger breast cancer survivors, have barely been examined. This study aimed to explore types and intensity of negative and positive emotional expression related to the breast cancer experience by younger and older Arab breast cancer survivors. Participants were 20 younger (aged 32-50) and 20 older (aged 51-75) Muslim and Christian Arab breast cancer survivors (stages I-III), currently free of disease. Data were gathered through in-depth semi-structured interviews. Mixed methods analyses were conducted, including: (1) frequency analysis of participants' emotional expressions; (2) content analysis of emotional expressions, categorized according to negative and positive emotions. Three emotional expression modalities were revealed: (1) Succinct versus comprehensive accounts; (2) expression of emotions versus avoidance of emotions; (3) patterns of expression of positive emotions and a sense of personal growth. Younger women provided more detailed accounts about their illness experiences than older women. Older women's accounts were succinct, action-focused, and included more emotion-avoiding expressions than younger women. Understanding the relationships between emotional expression, emotional experience, and cancer survivors' quality of life, specifically of those from traditional communities, is necessary for developing effective psycho-social interventions.

Neurophysiological and Behavioral Differences between Older and Younger Adults When Processing Violations of Tonal Structure in Music

Science.gov (United States)

Lagrois, Marie-Élaine; Peretz, Isabelle; Zendel, Benjamin Rich

2018-01-01

Aging is associated with decline in both cognitive and auditory abilities. However, evidence suggests that music perception is relatively spared, despite relying on auditory and cognitive abilities that tend to decline with age. It is therefore likely that older adults engage compensatory mechanisms which should be evident in the underlying functional neurophysiology related to processing music. In other words, the perception of musical structure would be similar or enhanced in older compared to younger adults, while the underlying functional neurophysiology would be different. The present study aimed to compare the electrophysiological brain responses of younger and older adults to melodic incongruities during a passive and active listening task. Older and younger adults had a similar ability to detect an out-of-tune incongruity (i.e., non-chromatic), while the amplitudes of the ERAN and P600 were reduced in older adults compared to younger adults. On the other hand, out-of-key incongruities (i.e., non-diatonic), were better detected by older adults compared to younger adults, while the ERAN and P600 were comparable between the two age groups. This pattern of results indicates that perception of tonal structure is preserved in older adults, despite age-related neurophysiological changes in how melodic violations are processed. PMID:29487498

Neurophysiological and Behavioral Differences between Older and Younger Adults When Processing Violations of Tonal Structure in Music

Directory of Open Access Journals (Sweden)

Marie-Élaine Lagrois

2018-02-01

Full Text Available Aging is associated with decline in both cognitive and auditory abilities. However, evidence suggests that music perception is relatively spared, despite relying on auditory and cognitive abilities that tend to decline with age. It is therefore likely that older adults engage compensatory mechanisms which should be evident in the underlying functional neurophysiology related to processing music. In other words, the perception of musical structure would be similar or enhanced in older compared to younger adults, while the underlying functional neurophysiology would be different. The present study aimed to compare the electrophysiological brain responses of younger and older adults to melodic incongruities during a passive and active listening task. Older and younger adults had a similar ability to detect an out-of-tune incongruity (i.e., non-chromatic, while the amplitudes of the ERAN and P600 were reduced in older adults compared to younger adults. On the other hand, out-of-key incongruities (i.e., non-diatonic, were better detected by older adults compared to younger adults, while the ERAN and P600 were comparable between the two age groups. This pattern of results indicates that perception of tonal structure is preserved in older adults, despite age-related neurophysiological changes in how melodic violations are processed.

A prospective follow-up study of younger and older subjects with pathological gambling.

Science.gov (United States)

Black, Donald W; Coryell, William; McCormick, Brett; Shaw, Martha; Allen, Jeff

2017-10-01

Pathological gambling (PG) is a common and costly public health problem associated with impaired quality of life and high suicide rates. Despite its frequency in the general population, PG course is poorly understood in older adults who are especially vulnerable to its devastating consequences. We enrolled 175 subjects in a longitudinal study of gambling behavior: our case group of 53 older adults with PG (≥ 60 years), and two comparison groups including 72 younger adults with PG (Gambling Screen (SOGS) and National Opinion Research Center DSM Screen for Gambling Problems (NODS) scores ≥ 5. Subjects were evaluated at intake and reassessed every 6 months and drop outs were replaced. Follow-up lasted a mean (SD) of 2.6 (1.4) years. At intake older PGs were more likely to be female, Caucasian, divorced, and to have a lower level of education. Older and younger PGs were similar in gambling severity, but older PGs were more likely to have sought PG treatment. Older PGs had lower rates of lifetime drug use disorders, attention deficit/hyperactivity disorder, and obsessive-compulsive disorder. They preferred slots, were more likely to receive PG treatment, and were less likely to discontinue participation in the study. Week by week gambling activity levels showed a significant general downward movement for older and younger PGs, although there were no differences between the groups. Elders without PG had no change in their level of gambling activity. We conclude that younger and older PGs moved toward a reduced level of gambling activity during follow-up. Our data challenge the notion that PG is chronic and progressive. Copyright © 2017 Elsevier B.V. All rights reserved.

Expressive Suppression and Enhancement During Music-Elicited Emotions in Younger and Older Adults

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Sandrine eVieillard

2015-02-01

Full Text Available When presented with emotional visual scenes, older adults have been found to be equally capable to regulate emotion expression as younger adults, corroborating the view that emotion regulation skills are maintained or even improved in later adulthood. However, the possibility that gaze direction might help achieve an emotion control goal has not been taken into account, raising the question whether the effortful processing of expressive regulation is really spared from the general age-related decline. Since it does not allow perceptual attention to be redirected away from the emotional source, music provides a useful way to address this question. In the present study, affective, behavioral and physiological consequences of free expression of emotion, expressive suppression and expressive enhancement were measured in 31 younger and 30 older adults while they listened to positive and negative musical excerpts. The main results indicated that compared to younger adults, older adults reported experiencing less emotional intensity in response to negative music during the free expression of emotion condition. No age difference was found in the ability to amplify or reduce emotional expressions. However, an age-related decline in the ability to reduce the intensity of emotional state and an age-related increase in physiological reactivity were found when participants were instructed to suppress negative expression. Taken together, the current data support previous findings suggesting an age-related change in response to music. They also corroborate the observation that older adults are as efficient as younger adults at controlling behavioral expression. But most importantly, they suggest that when faced with auditory sources of negative emotion, older age does not always confer a better ability to regulate emotions.

An exploration of the patient navigator role: perspectives of younger women with breast cancer.

Science.gov (United States)

Pedersen, Allison E; Hack, Thomas F; McClement, Susan E; Taylor-Brown, Jill

2014-01-01

To delineate the role of the oncology patient navigator, drawing from the experiences and descriptions of younger women with breast cancer. Interpretive, descriptive, qualitative research design. Participants' homes, researcher's home, and via telephone, all in Winnipeg, Manitoba, Canada. 12 women aged 50 years or younger who were diagnosed with breast cancer within the last three years. Face-to-face semistructured interviews explored patient experiences with the cancer care system, including problems encountered, unmet needs, and opinions about the functions of the patient navigator role. The audio-recorded interviews were transcribed and data were broken down and inductively coded into four categories. Constant comparative techniques also were used during analysis. The role of the oncology patient navigator included two facets: "Processual facets," with the subthemes assigned to me at diagnosis, managing the connection, mapping the process, practical support, and quarterbacking my entire journey; and "Personal qualities: The essentials," with the subthemes empathetic care tenor, knowing the cancer system, and understanding the medical side of breast cancer. Despite the tremendous effort directed toward enhancing care for younger women undergoing treatment for breast cancer, gaps continue to exist. Younger women with breast cancer require a care approach providing ongoing dialogue, teaching, and emotional support from the point of diagnosis through treatment, including transitions of care within the oncology setting and back to their primary care practitioner. Oncology nurse navigators are well positioned to provide patients with anticipatory guidance from diagnosis to the end of treatment.

TOT phenomena: Gesture production in younger and older adults.

Science.gov (United States)

Theocharopoulou, Foteini; Cocks, Naomi; Pring, Timothy; Dipper, Lucy T

2015-06-01

This study explored age-related changes in gesture to better understand the relationship between gesture and word retrieval from memory. The frequency of gestures during tip-of-the-tongue (TOT) states highlights this relationship. There is a lack of evidence describing the form and content of iconic gestures arising spontaneously in such TOT states and a parallel gap addressing age-related variations. In this study, TOT states were induced in 45 participants from 2 age groups (older and younger adults) using a pseudoword paradigm. The type and frequency of gestures produced was recorded during 2 experimental conditions (single-word retrieval and narrative task). We found that both groups experienced a high number of TOT states, during which they gestured. Iconic co-TOT gestures were more common than noniconic gestures. Although there was no age effect on the type of gestures produced, there was a significant, task-specific age difference in the amount of gesturing. That is, younger adults gestured more in the narrative task, whereas older adults generated more gestures in the single-word-retrieval task. Task-specific age differences suggest that there are age-related differences in terms of the cognitive operations involved in TOT gesture production. (c) 2015 APA, all rights reserved.

Phasic alerting increases visual attention capacity in younger but not in older individuals

DEFF Research Database (Denmark)

Wiegand, Iris Michaela; Petersen, Anders; Bundesen, Claus

2017-01-01

In the present study, we investigated effects of phasic alerting on visual attention in younger and older adults. We modelled parameters of visual attention based on the computational Theory of Visual Attention (TVA) and measured event-related lateralizations (ERLs) in a partial report task, in w...... and attention, which governs the responsiveness to external cues and is critical for general cognitive functioning in aging.......In the present study, we investigated effects of phasic alerting on visual attention in younger and older adults. We modelled parameters of visual attention based on the computational Theory of Visual Attention (TVA) and measured event-related lateralizations (ERLs) in a partial report task...

Younger adults and homeownership in Europe through the global financial crisis

NARCIS (Netherlands)

Lennartz, C.; Arundel, R.; Ronald, R.

2016-01-01

In the context of poorly performing national economies and sustained employment insecurity since the Global Financial Crisis of 2007-2008, various UK and US studies have suggested that the transitions of younger people into independent living and into homeownership, in particular, have been in

The effects of emotional television advertising on older and younger adults

NARCIS (Netherlands)

van der Goot, M.J.; van Reijmersdal, E.A.; Kleemans, M.; Verlegh, P.; Voorveld, H.; Eisend, M.

2016-01-01

Understanding older adults’ responses to advertising is vital for the industry because older adults constitute a large and lucrative market: The world population is aging (United Nations, 2012) and consumers of 50 years and older have more disposable income than younger consumers (e.g., Ahmad, 2003;

After total knee replacement younger patients demonstrate superior balance control compared to older patients when recovering from a forward fall.

Science.gov (United States)

Street, Brian D; Gage, William

2017-05-01

National joint replacement registries have reported a substantial growth in younger knee osteoarthritic patients (controlled perturbation have shown age-related differences between younger and older healthy adults, whether similar age-related differences exist among total knee replacement patients is unknown. A total of 59 participants, including 29 unilateral total knee replacement patients (six-months post-surgery) made up the four experimental groups: 1) younger patient (54.3 (SD 7.9) years), 2) younger control (55.2 (SD 4.0) years), 3) older patient (76.9 (SD 4.7) years), and 4) older control (77.7 (SD 4.1) years). Using a tether-release method to perturb balance and simulate a forward fall, center of mass and stepping characteristics were analyzed. Younger patients recovered following the perturbation with a significantly smaller center of mass displacement compared to the older patients (14.85 (SD 0.01) v. 18.13 (SD 0.02) %ht, p=0.02); utilizing a longer (0.43 (SD 0.02) v. 0.39 (SD 0.03) m, pcontrols in center of mass displacement or recovery step characteristics (p>0.05). The younger patients demonstrated superior center of mass control in response to a forward perturbation, suggesting that younger patients would be at a reduced risk of falling when recovering from a forward-directed postural perturbation compared to older patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

Clear speech and lexical competition in younger and older adult listeners.

Science.gov (United States)

Van Engen, Kristin J

2017-08-01

This study investigated whether clear speech reduces the cognitive demands of lexical competition by crossing speaking style with lexical difficulty. Younger and older adults identified more words in clear versus conversational speech and more easy words than hard words. An initial analysis suggested that the effect of lexical difficulty was reduced in clear speech, but more detailed analyses within each age group showed this interaction was significant only for older adults. The results also showed that both groups improved over the course of the task and that clear speech was particularly helpful for individuals with poorer hearing: for younger adults, clear speech eliminated hearing-related differences that affected performance on conversational speech. For older adults, clear speech was generally more helpful to listeners with poorer hearing. These results suggest that clear speech affords perceptual benefits to all listeners and, for older adults, mitigates the cognitive challenge associated with identifying words with many phonological neighbors.

Attachment and Aggressive Manifestations in Younger Adulthood - "Preliminary Findings"

Directory of Open Access Journals (Sweden)

Tatiana Lorincová

2014-07-01

Full Text Available The main topic of the contribution was comparison between retrospective attachment (emocional warmth and rejection and aggressive manifestations (physical aggressivness, verbal aggressivness, anger and hostility among younger adulthood. Bowlby's theory of attachment was that once a core attachment style develops in an infant, it will influence and shape the nature of all intimate relations for the individual moving forward throughout the infant's life cycle. Authors Mikulincer and Shaver (2011 explain how these primary attachment experiences would affect future emotional, cognitive and behavioral processes. Secure adolescents, in comparison to insecure ones are perceived as being less aggressive. Research has pointed out that secure parental attachment promotes adaptive psychological functioning. The direct relationship between attachment security and aggressive/delinquent behaviour is in line with prior evidence that secure adolescents rate higher in terms of emotional and social adjustment, enjoy more positive relationships with their family and peers, and are less likely to engage in externalizing problems, such as antisocial and aggressive behaviours. On the other hand, insecure attachment is connected with aggressive and externalizing behaviour. Hypotheses were formulated on the base of theoretical background and our assumption was, that younger adults with emocional warmth attachment will have lower level of aggressive manifestations (physical aggression, verbal aggression, anger and hostility than younger adults with rejectional attachment. We used two standardized questionnaires for data collection, s.E.M.B.U. Questionnaire, which measured retrospective attachment (emocional warmth and rejection and Questionnaire of Aggressivness, which measured aggressive manifestations. We used statistical analysis and we found statistically significant differencies, which are preliminary findings from broader research, between emocional warmth

Utilization and Outcomes of Breast Brachytherapy in Younger Women

International Nuclear Information System (INIS)

Smith, Grace L.; Huo, Jinhai; Giordano, Sharon H.; Hunt, Kelly K.; Buchholz, Thomas A.; Smith, Benjamin D.

2015-01-01

Purpose: To directly compare (1) radiation treatment utilization patterns; (2) risks of subsequent mastectomy; and (3) costs of radiation treatment in patients treated with brachytherapy versus whole-breast irradiation (WBI), in a national, contemporary cohort of women with incident breast cancer, aged 64 years and younger. Methods and Materials: Using MarketScan health care claims data, we identified 45,884 invasive breast cancer patients (aged 18-64 years), treated from 2003 to 2010 with lumpectomy, followed by brachytherapy (n=3134) or whole-breast irradiation (n=42,750). We stratified patients into risk groups according to age (Age<50 vs Age≥50) and endocrine therapy status (Endocrine− vs Endocrine+). “Endocrine+” patients filled an endocrine therapy prescription within 1 year after lumpectomy. Pathologic hormone receptor status was not available in this dataset. In brachytherapy versus WBI patients, utilization trends and 5-year subsequent mastectomy risks were compared. Stratified, adjusted subsequent mastectomy risks were calculated using proportional hazards regression. Results: Brachytherapy utilization increased from 2003 to 2010: in patients Age<50, from 0.6% to 4.9%; patients Age≥50 from 2.2% to 11.3%; Endocrine− patients, 1.3% to 9.4%; Endocrine+ patients, 1.9% to 9.7%. Age influenced treatment selection more than endocrine status: 17% of brachytherapy patients were Age<50 versus 32% of WBI patients (P<.001); whereas 41% of brachytherapy patients were Endocrine–versus 44% of WBI patients (P=.003). Highest absolute 5-year subsequent mastectomy risks occurred in Endocrine−/Age<50 patients (24.4% after brachytherapy vs 9.0% after WBI (hazard ratio [HR] 2.18, 95% confidence interval [CI] 1.37-3.47); intermediate risks in Endocrine−/Age≥50 patients (8.6% vs 4.9%; HR 1.76, 95% CI 1.26-2.46); and lowest risks in Endocrine+ patients of any age: Endocrine+/Age<50 (5.5% vs 4.5%; HR 1.18, 95% CI 0.61-2.31); Endocrine+/Age≥50 (4.2% vs 2

Utilization and Outcomes of Breast Brachytherapy in Younger Women

Energy Technology Data Exchange (ETDEWEB)

Smith, Grace L. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Huo, Jinhai [Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Giordano, Sharon H. [Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Hunt, Kelly K. [Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Buchholz, Thomas A. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Smith, Benjamin D., E-mail: bsmith3@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

2015-09-01

Purpose: To directly compare (1) radiation treatment utilization patterns; (2) risks of subsequent mastectomy; and (3) costs of radiation treatment in patients treated with brachytherapy versus whole-breast irradiation (WBI), in a national, contemporary cohort of women with incident breast cancer, aged 64 years and younger. Methods and Materials: Using MarketScan health care claims data, we identified 45,884 invasive breast cancer patients (aged 18-64 years), treated from 2003 to 2010 with lumpectomy, followed by brachytherapy (n=3134) or whole-breast irradiation (n=42,750). We stratified patients into risk groups according to age (Age<50 vs Age≥50) and endocrine therapy status (Endocrine− vs Endocrine+). “Endocrine+” patients filled an endocrine therapy prescription within 1 year after lumpectomy. Pathologic hormone receptor status was not available in this dataset. In brachytherapy versus WBI patients, utilization trends and 5-year subsequent mastectomy risks were compared. Stratified, adjusted subsequent mastectomy risks were calculated using proportional hazards regression. Results: Brachytherapy utilization increased from 2003 to 2010: in patients Age<50, from 0.6% to 4.9%; patients Age≥50 from 2.2% to 11.3%; Endocrine− patients, 1.3% to 9.4%; Endocrine+ patients, 1.9% to 9.7%. Age influenced treatment selection more than endocrine status: 17% of brachytherapy patients were Age<50 versus 32% of WBI patients (P<.001); whereas 41% of brachytherapy patients were Endocrine–versus 44% of WBI patients (P=.003). Highest absolute 5-year subsequent mastectomy risks occurred in Endocrine−/Age<50 patients (24.4% after brachytherapy vs 9.0% after WBI (hazard ratio [HR] 2.18, 95% confidence interval [CI] 1.37-3.47); intermediate risks in Endocrine−/Age≥50 patients (8.6% vs 4.9%; HR 1.76, 95% CI 1.26-2.46); and lowest risks in Endocrine+ patients of any age: Endocrine+/Age<50 (5.5% vs 4.5%; HR 1.18, 95% CI 0.61-2.31); Endocrine+/Age≥50 (4.2% vs 2

Differing Effects of Younger and Older Human Plasma on C2C12 Myocytes in Vitro

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Ifigeneia Kalampouka

2018-02-01

Full Text Available Ageing is associated with a general reduction of physiological function and a reduction of muscle mass and strength. Endocrine factors such as myostatin, activin A, growth and differentiation factor 11 (GDF-11 and their inhibitory peptides influence muscle mass in health and disease. We hypothesised that myocytes cultured in plasma from older and younger individuals would show an ageing effect, with reduced proliferation and differentiation in older environments. C2C12 myoblasts were grown as standard and stimulated with media conditioned with 5% plasma from healthy male participants that were either younger (n = 6, 18–35 years of age or older (n = 6, >57 years of age. Concentration of plasma myostatin (total and free, follistatin-like binding protein (FLRG, GDF-11 and activin A were quantified by ELISA. Both FLRG and activin A were elevated in older individuals (109.6 and 35.1% increase, respectively, whilst myostatin (free and total and GDF-11 were not. Results indicated that plasma activin A and FLRG were increased in older vs. younger participants, GDF11 and myostatin did not differ. Myoblasts in vitro showed no difference in proliferation rate between ages, however scratch closure was greater in younger vs. older plasma stimulated myoblasts (78.2 vs. 87.2% of baseline scratch diameter, respectively. Myotube diameters were larger in cells stimulated with younger plasma than with older at 24 and 48 h, but not at 2 h. A significant negative correlation was noted between in vivo plasma FLRG concentration and in vitro myotube diameter 48 h following plasma stimulation (r2 = 0.392, p = 0.030. Here we show that myoblasts and myotubes cultured in media conditioned with plasma from younger or older individuals show an ageing effect, and further this effect moderately correlates with circulating FLRG concentration in vivo. The effect of ageing on muscle function may not be innate to the tissue, but involve a general cellular environment change

Prognosis of localized diffuse large B-cell lymphoma in younger patients

DEFF Research Database (Denmark)

Møller, Michael B; Christensen, Bjarne E; Pedersen, Niels T

2003-01-01

BACKGROUND: The International Prognostic Index (IPI) is widely used as a predictive model in diffuse large B-cell lymphoma (DLBCL) patients of all ages and stages. To determine the optimal IPI-based prognostic system at the time of diagnosis in younger patients with limited-stage DLBCL, the authors...

Younger but not older adults benefit from salient feedback during learning

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Michael eHerbert

2011-08-01

Full Text Available Older adults are impaired in reinforcement learning (RL when feedback is partially ambiguous (e.g., Eppinger and Kray, 2011. In this study we examined whether older adults benefit from salient feedback information during learning. We used an electrophysiological approach and investigated 15 younger and 15 older adults with a RL task in which they had to learn stimulus-response associations under two learning conditions. In the positive learning conditions, participants could gain 50 Cents for a correct response but did not gain or lose money (*00 Cent for an incorrect response. In negative learning conditions, they could lose 50 Cents for an incorrect response but did not gain or lose money (*00 Cent for a correct response. As the identical outcome 00 Cent is either better or worse than the alternative outcome depending on the learning condition, this feedback type is ambiguous. To examine the influence of feedback salience we compared this condition with a condition in which positive and negative outcomes were color-coded and thereby clearly separable. The behavioral results indicated that younger adults reached higher accuracy levels under salient feedback conditions. Moreover, the error-related negativity (ERN and the feedback-related negativity (FRN for losses were larger if the good-bad dimension of feedback was salient. Hence, in younger adults salient feedback facilitates the rapid evaluation of outcomes on a good-bad dimension and by this supports learning. In contrast, for older adults we obtained neither behavioral nor electrophysiological effects of feedback salience. The older adults’ performance monitoring system therefore appears less flexible in integrating additional information in this evaluation process.

State-based versus reward-based motivation in younger and older adults.

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Worthy, Darrell A; Cooper, Jessica A; Byrne, Kaileigh A; Gorlick, Marissa A; Maddox, W Todd

2014-12-01

Recent decision-making work has focused on a distinction between a habitual, model-free neural system that is motivated toward actions that lead directly to reward and a more computationally demanding goal-directed, model-based system that is motivated toward actions that improve one's future state. In this article, we examine how aging affects motivation toward reward-based versus state-based decision making. Participants performed tasks in which one type of option provided larger immediate rewards but the alternative type of option led to larger rewards on future trials, or improvements in state. We predicted that older adults would show a reduced preference for choices that led to improvements in state and a greater preference for choices that maximized immediate reward. We also predicted that fits from a hybrid reinforcement-learning model would indicate greater model-based strategy use in younger than in older adults. In line with these predictions, older adults selected the options that maximized reward more often than did younger adults in three of the four tasks, and modeling results suggested reduced model-based strategy use. In the task where older adults showed similar behavior to younger adults, our model-fitting results suggested that this was due to the utilization of a win-stay-lose-shift heuristic rather than a more complex model-based strategy. Additionally, within older adults, we found that model-based strategy use was positively correlated with memory measures from our neuropsychological test battery. We suggest that this shift from state-based to reward-based motivation may be due to age related declines in the neural structures needed for more computationally demanding model-based decision making.

Carbon and hydrogen isotopic composition of methane and C2+ alkanes in electrical spark discharge: implications for identifying sources of hydrocarbons in terrestrial and extraterrestrial settings.

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Telling, Jon; Lacrampe-Couloume, Georges; Sherwood Lollar, Barbara

2013-05-01

The low-molecular-weight alkanes--methane, ethane, propane, and butane--are found in a wide range of terrestrial and extraterrestrial settings. The development of robust criteria for distinguishing abiogenic from biogenic alkanes is essential for current investigations of Mars' atmosphere and for future exobiology missions to other planets and moons. Here, we show that alkanes synthesized during gas-phase radical recombination reactions in electrical discharge experiments have values of δ(2)H(methane)>δ(2)H(ethane)>δ(2)H(propane), similar to those of the carbon isotopes. The distribution of hydrogen isotopes in gas-phase radical reactions is likely due to kinetic fractionations either (i) from the preferential incorporation of (1)H into longer-chain alkanes due to the more rapid rate of collisions of the smaller (1)H-containing molecules or (ii) by secondary ion effects. Similar δ(13)C(C1-C2+) and δ(2)H(C1-C2+) patterns may be expected in a range of extraterrestrial environments where gas-phase radical reactions dominate, including interstellar space, the atmosphere and liquid hydrocarbon lakes of Saturn's moon Titan, and the outer atmospheres of Jupiter, Saturn, Neptune, and Uranus. Radical recombination reactions at high temperatures and pressures may provide an explanation for the combined reversed δ(13)C(C1-C2+) and δ(2)H(C1-C2+) patterns of terrestrial alkanes documented at a number of high-temperature/pressure crustal sites.

Deep ice and salty oceans of icy worlds, how high pressures influence their thermodynamics and provide constrains on extraterrestrial habitability

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Journaux, B.; Brown, J. M.; Bollengier, O.; Abramson, E.

2017-12-01

As in Earth arctic and Antarctic regions, suspected extraterrestrial deep oceans in icy worlds (i.e. icy moons and water-rich exoplanets) chemistry and thermodynamic state will strongly depend on their equilibrium with H2O ice and present solutes. Na-Mg-Cl-SO4 salt species are currently the main suspected ionic solutes to be present in deep oceans based on remote sensing, magnetic field measurements, cryovolcanism ice grains chemical analysis and chondritic material aqueous alteration chemical models. Unlike on our planet, deep extraterrestrial ocean might also be interacting at depth with high pressure ices (e.g. III, V, VI, VI, X) which have different behavior compared to ice Ih. Unfortunately, the pressures and temperatures inside these hydrospheres differ significantly from the one found in Earth aqueous environments, so most of our current thermodynamic databases do not cover the range of conditions relevant for modeling realistically large icy worlds interiors. Recent experimental results have shown that the presence of solutes, and more particularly salts, in equilibrium with high pressure ices have large effects on the stability, buoyancy and chemistry of all the phases present at these extreme conditions. High pressure in-situ measurements using diamond anvil cell apparatus were operated both at the University of washington and at the European Synchrotron Radiation Facility on aqueous systems phase diagrams with Na-Mg-Cl-SO4 species, salt incorporation in high pressure ices and density inversions between the solid and the fluids. These results suggest a more complex picture of the interior structure, dynamic and chemical evolution of large icy worlds hydrospheres when solutes are taken into account, compared to current models mainly using pure water. Based on our in-situ experimental measurements, we propose the existence of new liquid environments at greater depths and the possibility of solid state transport of solute through the high pressure ices

Younger and older adults' collaborative recall of shared and unshared emotional pictures.

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Barber, Sarah J; Castrellon, Jaime J; Opitz, Philipp; Mather, Mara

2017-07-01

Although a group of people working together recalls more items than any one individual, they recall fewer unique items than the same number of people working apart whose responses are combined. This is known as collaborative inhibition, and it is a robust effect that occurs for both younger and older adults. However, almost all previous studies documenting collaborative inhibition have used stimuli that were neutral in emotional valence, low in arousal, and studied by all group members. In the current experiments, we tested the impact of picture-stimuli valence, picture-stimuli arousal, and information distribution in modulating the magnitude of collaborative inhibition. We included both younger and older adults because there are age differences in how people remember emotional pictures that could modulate any effects of emotion on collaborative inhibition. Results revealed that when information was shared (i.e., studied by all group members), there were robust collaborative inhibition effects for both neutral and emotional stimuli for both younger and older adults. However, when information was unshared (i.e., studied by only a single group member), these effects were attenuated. Together, these results provide mixed support for the retrieval strategy disruption account of collaborative inhibition. Supporting the retrieval strategy disruption account, unshared study information was less susceptible to collaborative inhibition than shared study information. Contradicting the retrieval strategy disruption account, emotional valence and arousal did not modulate the magnitude of collaborative inhibition despite the fact that participants clustered the emotional, but not neutral, information together in memory.

Action prediction in younger versus older adults: neural correlates of motor familiarity.

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Nadine Diersch

Full Text Available Generating predictions during action observation is essential for efficient navigation through our social environment. With age, the sensitivity in action prediction declines. In younger adults, the action observation network (AON, consisting of premotor, parietal and occipitotemporal cortices, has been implicated in transforming executed and observed actions into a common code. Much less is known about age-related changes in the neural representation of observed actions. Using fMRI, the present study measured brain activity in younger and older adults during the prediction of temporarily occluded actions (figure skating elements and simple movement exercises. All participants were highly familiar with the movement exercises whereas only some participants were experienced figure skaters. With respect to the AON, the results confirm that this network was preferentially engaged for the more familiar movement exercises. Compared to younger adults, older adults recruited visual regions to perform the task and, additionally, the hippocampus and caudate when the observed actions were familiar to them. Thus, instead of effectively exploiting the sensorimotor matching properties of the AON, older adults seemed to rely predominantly on the visual dynamics of the observed actions to perform the task. Our data further suggest that the caudate played an important role during the prediction of the less familiar figure skating elements in better-performing groups. Together, these findings show that action prediction engages a distributed network in the brain, which is modulated by the content of the observed actions and the age and experience of the observer.

Cardiovascular reactivity of younger and older adults to positive-, negative-, and mixed-emotion cognitive challenge.

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Hogan, Michael J; James, Jack E; McCabe, Tadhg R; Kilmartin, Liam; Howard, Siobhán; Noone, Chris

2012-03-01

Although aging is associated with progressive increases in blood pressure level, previous research has been inconsistent as to whether older adults show greater or lesser cardiovascular reactivity (CVR) to emotion than do younger adults. There is reason to believe that these inconsistencies could be clarified by examining age-related differences in hemodynamic profile revealed by measuring the pattern of cardiac output and total peripheral resistance associated with changes in blood pressure reactivity. Accordingly, the present study examined the performance, CVR, and hemodynamic profile of younger and older adults during encoding and recognition of word pairs involving four valence types: positive, negative, mixed (positive/negative), and neutral word pairs. Results revealed higher baseline blood pressure, increased CVR characterized by a vascular hemodynamic profile, and more rapid recovery (especially during encoding) for older than for younger participants. Results are discussed in light of research and theory on the relationship between aging and cardiovascular health. Copyright © 2012 Elsevier B.V. All rights reserved.

Accretion rate of extraterrestrial {sup 41}Ca in Antarctic snow samples

Energy Technology Data Exchange (ETDEWEB)

Gómez-Guzmán, J.M., E-mail: jose.gomez@ph.tum.de [Technische Universität München, Fakultät für Physik, James-Franck-Strasse 1, 85748 Garching (Germany); Bishop, S.; Faestermann, T.; Famulok, N.; Fimiani, L.; Hain, K.; Jahn, S.; Korschinek, G.; Ludwig, P. [Technische Universität München, Fakultät für Physik, James-Franck-Strasse 1, 85748 Garching (Germany); Rodrigues, D. [Laboratorio TANDAR, Comisión Nacional de Energía Atómica (Argentina)

2015-10-15

Interplanetary Dust Particles (IDPs) are small grains, generally less than a few hundred micrometers in size. Their main source is the Asteroid Belt, located at 3 AU from the Sun, between Mars and Jupiter. During their flight from the Asteroid Belt to the Earth they are irradiated by galactic and solar cosmic rays (GCR and SCR), thus radionuclides are formed, like {sup 41}Ca and {sup 53}Mn. Therefore, {sup 41}Ca (T{sub 1/2} = 1.03 × 10{sup 5} yr) can be used as a key tracer to determine the accretion rate of IDPs onto the Earth because there are no significant terrestrial sources for this radionuclide. The first step of this study consisted to calculate the production rate of {sup 41}Ca in IDPs accreted by the Earth during their travel from the Asteroid Belt. This production rate, used in accordance with the {sup 41}Ca/{sup 40}Ca ratios that will be measured in snow samples from the Antarctica will be used to calculate the amount of extraterrestrial material accreted by the Earth per year. There challenges for this project are, at first, the much longer time for the flight needed by the IDPs to travel from the Asteroid Belt to the Earth in comparison with the {sup 41}Ca half-life yields an early saturation for the {sup 41}Ca/{sup 40}Ca ratio, and second, the importance of selecting the correct sampling site to avoid a high influx of natural {sup 40}Ca, preventing dilution of the {sup 41}Ca/{sup 40}Ca ratio, the quantity measured by AMS.

The gain of single-axis tracked panel according to extraterrestrial radiation

International Nuclear Information System (INIS)

Chang, T.P.

2009-01-01

In the present study, the gain in extraterrestrial radiation received by a single-axis tracked panel relative to a fixed panel was systematically analyzed over a specific period of time. The dynamic angle that the tracked panel should rotate by in order to follow the sun was derived through a series of spherical trigonometric procedures. The instantaneous incident angle of sunlight upon the panel was then calculated, assuming that the panel would simultaneously follow the sun's position. Thus, instantaneous increments of solar energy received by the tracked panel relative to the fixed panel are originally presented. The results show that the angle the tracked panel has to rotate by is 0 deg. at solar noon, and increases towards dawn or dusk. The incident angle of sunlight upon the tracked panel is always smaller than that upon the fixed panel, except at solar noon. As for panels installed with a yearly optimal tilt angle in Taipei, the gains are between 36.3% and 62.1% for four particular days of year, between 37.8% and 60.8% for the four seasons and 49.3% over the entire year. The amount of radiation collected by the tracked panel is enhanced as the maximum rotation angle is increased. The irradiation ratio of the tracked panel to the fixed panel is close to 1.5 for latitudes below 65 deg. and gradually increases for latitudes above this. The yearly optimal tilt angle of a south-facing fixed panel is approximately equal to 0.9 multiplied by the latitude (i.e. 0.9 x φ) for latitudes below 65 deg. and is about 56 + 0.4 x (φ - 65) otherwise

Memory for general and specific value information in younger and older adults: measuring the limits of strategic control.

Science.gov (United States)

Castel, Alan D; Farb, Norman A S; Craik, Fergus I M

2007-06-01

The ability to selectively remember important information is a critical function of memory. Although previous research has suggested that older adults are impaired in a variety of episodic memory tasks, recent work has demonstrated that older adults can selectively remember high-value information. In the present research, we examined how younger and older adults selectively remembered words with various assigned numeric point values, to see whether younger adults could remember more specific value information than could older adults. Both groups were equally good at recalling point values when recalling the range of high-value words, but younger adults outperformed older adults when recalling specific values. Although older adults were more likely to recognize negative value words, both groups exhibited control by not recalling negative value information. The findings suggest that although both groups retain high-value information, older adults rely more on gist-based encoding and retrieval operations, whereas younger adults are able to remember specific numeric value information.

ERP evidence that auditory-visual speech facilitates working memory in younger and older adults.

Science.gov (United States)

Frtusova, Jana B; Winneke, Axel H; Phillips, Natalie A

2013-06-01

Auditory-visual (AV) speech enhances speech perception and facilitates auditory processing, as measured by event-related brain potentials (ERPs). Considering a perspective of shared resources between perceptual and cognitive processes, facilitated speech perception may render more resources available for higher-order functions. This study examined whether AV speech facilitation leads to better working memory (WM) performance in 23 younger and 20 older adults. Participants completed an n-back task (0- to 3-back) under visual-only (V-only), auditory-only (A-only), and AV conditions. The results showed faster responses across all memory loads and improved accuracy in the most demanding conditions (2- and 3-back) during AV compared with unisensory conditions. Older adults benefited from the AV presentation to the same extent as younger adults. WM performance of older adults during the AV presentation did not differ from that of younger adults in the A-only condition, suggesting that an AV presentation can help to counteract some of the age-related WM decline. The ERPs showed a decrease in the auditory N1 amplitude during the AV compared with A-only presentation in older adults, suggesting that the facilitation of perceptual processing becomes especially beneficial with aging. Additionally, the N1 occurred earlier in the AV than in the A-only condition for both age groups. These AV-induced modulations of auditory processing correlated with improvement in certain behavioral and ERP measures of WM. These results support an integrated model between perception and cognition, and suggest that processing speech under AV conditions enhances WM performance of both younger and older adults. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Relationship between perceptual learning in speech and statistical learning in younger and older adults

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Thordis Marisa Neger

2014-09-01

Full Text Available Within a few sentences, listeners learn to understand severely degraded speech such as noise-vocoded speech. However, individuals vary in the amount of such perceptual learning and it is unclear what underlies these differences. The present study investigates whether perceptual learning in speech relates to statistical learning, as sensitivity to probabilistic information may aid identification of relevant cues in novel speech input. If statistical learning and perceptual learning (partly draw on the same general mechanisms, then statistical learning in a non-auditory modality using non-linguistic sequences should predict adaptation to degraded speech.In the present study, 73 older adults (aged over 60 years and 60 younger adults (aged between 18 and 30 years performed a visual artificial grammar learning task and were presented with sixty meaningful noise-vocoded sentences in an auditory recall task. Within age groups, sentence recognition performance over exposure was analyzed as a function of statistical learning performance, and other variables that may predict learning (i.e., hearing, vocabulary, attention switching control, working memory and processing speed. Younger and older adults showed similar amounts of perceptual learning, but only younger adults showed significant statistical learning. In older adults, improvement in understanding noise-vocoded speech was constrained by age. In younger adults, amount of adaptation was associated with lexical knowledge and with statistical learning ability. Thus, individual differences in general cognitive abilities explain listeners' variability in adapting to noise-vocoded speech. Results suggest that perceptual and statistical learning share mechanisms of implicit regularity detection, but that the ability to detect statistical regularities is impaired in older adults if visual sequences are presented quickly.

Assessing the nutritional information for children younger than two years old available on popular websites

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Gisele da Silva Gomes Monteiro

Full Text Available Abstract Objective: To analyze whether the information found on popular Internet sites are in accordance with the steps recommended by the Food Guide for Children Younger than Two Years of the Ministry of Health (2010. Methods: Descriptive/comparative study, carried out between August and October 2014, which carried out a search for popular sites (for lay people in Portuguese, containing information on nutrition of children younger than two years. The Google search engine was used. These findings were compared with the Food Guide for Children Younger than Two Years of the Ministry of Health (2010. It was verified whether the information shown on the websites was in accordance with the Guide. Results: A total of 50 sites were analyzed, including blogs, food company websites and websites specialized in child nutrition. Only 10% of those pages correctly showed every step of the Food Guide. The recommendations were: exclusive breastfeeding up to six months of life (80%; complementary feeding from six months of life (36%; baby food consistency according to the guide (48%; encouraging the consumption of fruits and vegetables daily (60%. Regarding the complementary feeding safety and hygiene, 26% contained correct information. Only 36% correctly warned about which foods should be avoided in the first years of life. Conclusions: The information found on the sites is largely in disagreement with the Ministry of Health recommendations, which can lead to misconceptions in the nutritional care of the children younger than two years.

Comparison of tinnitus and psychological aspects between the younger and older adult patients with tinnitus.

Science.gov (United States)

Park, So Young; Han, Jung Ju; Hwang, Jae Hyung; Whang, Eul Sung; Yeo, Sang Won; Park, Shi Nae

2017-04-01

To explore the differences in various tinnitus-related features and psychological aspects between the younger and older adult patients with tinnitus. We retrospectively reviewed the clinical data of the adult patients who visited our tinnitus clinic in 2013 and completed full tinnitus assessment including audiometry, tinnitus matching, standardized tinnitus questionnaires, and psychometric questionnaires. The younger group included patients aged 20-45 years (n=64), and the older group, those older than 65 years (n=76). Clinical features, hearing levels, matched tinnitus pitches and loudness, self-report tinnitus severity scores, Beck depression inventory scores, and stress scores were compared between the groups. Tinnitus duration was longer in the older group (p=0.002). Mean PTAs were 16dB HL in the younger, and 38dB HL in the older groups (ptinnitus loudness was greater in the older group (64dB HL vs. 36dB HL, ptinnitus, depression, and stress scores did not differ between the groups. The older patients seemed to be more receptive to tinnitus. The majority of older tinnitus patients had concomitant hearing loss, and thus hearing rehabilitation should be considered preferentially for tinnitus management in this age group. Subjective tinnitus severity, depressive symptoms, and the stress levels were similar between the younger and older tinnitus patients. Therefore, treatment could be planned based upon the comprehensive understanding of the tinnitus characteristics and psychological aspects in each patient irrespective of age. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Expiratory flow limitation and operating lung volumes during exercise in older and younger adults.

Science.gov (United States)

Smith, Joshua R; Kurti, Stephanie P; Meskimen, Kayla; Harms, Craig A

2017-06-01

We determined the effect of aging on expiratory flow limitation (EFL) and operating lung volumes when matched for lung size. We hypothesized that older adults will exhibit greater EFL and increases in EELV during exercise compared to younger controls. Ten older (5M/5W; >60years old) and nineteen height-matched young adults (10M/9W) were recruited. Young adults were matched for%predicted forced vital capacity (FVC) (Y-matched%Pred FVC; n=10) and absolute FVC (Y-matched FVC; n=10). Tidal flow-volume loops were recorded during the incremental exercise test with maximal flow-volume loops measured pre- and post-exercise. Compared to younger controls, older adults exhibited more EFL at ventilations of 26, 35, 51, and 80L/min. The older group had higher end-inspiratory lung volume compared to Y-matched%Pred FVC group during submaximal ventilations. The older group increased EELV during exercise, while EELV stayed below resting in the Y-matched%Pred FVC group. These data suggest older adults exhibit more EFL and increase EELV earlier during exercise compared to younger adults. Copyright © 2017 Elsevier B.V. All rights reserved.

THE MODEL OF MOTOR ACTIVITY OPTIMIZATION OF YOUNGER SCHOOL AGE CHILDREN LIVING IN THE CONDITIONS OF THE NORTHERN CITY

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Zhanna Ildarovna Busheva

2017-10-01

Full Text Available Extreme conditions of the North, computerization, Internet and a gadget dependence, high physical and intellectual loads of children activities living in the north negatively affect younger generation health state. It is difficult to overestimate a role of motor activity in expansion of functionality of the developing organism as the lack of locomotion can lead to pathological shifts in an organism. Based on the study of the concept of a ‘motor activity’ and features North of the city the article suggests a model of motor activity optimization of younger school age children living in the conditions of the northern city. It consisted of 6 units related to goal-setting, diagnostic-analytical, concept, process-activity, reflexive-evaluative and effective. The research was conducted on the basis of Surgut city schools and the Surgut region of Khanty-Mansi Autonomous Region-Yugra. During the research we revealed the most priority organization forms of motor activity of younger school age children living in conditions of the northern city. The model of motor activity optimization of younger school age children allows to create necessary optimum volume and to control of motor activity of children of younger school age. Purpose. The purpose of our research was to create model of motor activity optimization of younger school age children living in the conditions of the northern city. Methodology. Analysis and synthesis of the materials as well as the method of simulation are used as the main instruments. Results. A model of motor activity optimization of younger school age children has been elaborated in the course of study and its characteristics have been specified. Practical implications. The results can be of use for teachers at professional educational institutions.

Lower extremity venous thrombosis in patients younger than 50 years of age

Directory of Open Access Journals (Sweden)

Kreidy R

2012-03-01

Full Text Available Raghid Kreidy1, Pascale Salameh2, Mirna Waked31Department of Vascular Surgery, Saint George Hospital, University Medical Center, University of Balamand, 2Laboratory of Clinical and Epidemiological Research, Faculty of Pharmacy, Lebanese University, 3Department of Pulmonary Medicine, Saint George Hospital, University Medical Center, University of Balamand, Beirut, LebanonAim: Lower extremity deep venous thrombosis in the young adult is uncommon and has not been well studied in the literature. The aim of this study is to define risk factors for deep venous thrombosis among patients younger than 50 years of age, to compare them with a control group, and to suggest recommendations for the management and treatment of venous thrombosis in this particular group of patients.Methods: From January 2003 to January 2011, 66 consecutive Lebanese patients (29 males and 37 females younger than 50 years, diagnosed in an academic tertiary-care center with lower extremity deep venous thrombosis by color flow duplex scan, were retrospectively reviewed. Their age varied between 21 and 50 years (mean 38.7 years. The control group included 217 patients (86 males and 131 females older than 50 years (range: 50–96 years; mean 72.9 years.Results: The most commonly reported risk factors in the younger age group were inherited thrombophilia (46.9% compared with 13.8% in the control group; P < 0.001, pregnancy (18.2% compared with 0.5%; P < 0.001, treatment with estrogen drugs (13.6% compared with 2.3%; P = 0.001, and family history of venous thromboembolism (9.1% compared with 3.8%; P = 0.084.Conclusion: Inherited thrombophilia is the most commonly observed risk factor among patients younger than 50 years, with a prevalence of three times more than the control group. Young adults should be screened for thrombophilia even in the presence of transient acquired risk factors. Pregnancy and treatment with estrogen drugs essentially when associated with inherited thrombophilia

Local Medicaid home- and community-based services spending and nursing home admissions of younger adults.

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Thomas, Kali S; Keohane, Laura; Mor, Vincent

2014-11-01

We used fixed-effect models to examine the relationship between local spending on home- and community-based services (HCBSs) for cash-assisted Medicaid-only disabled (CAMOD) adults and younger adult admissions to nursing homes in the United States during 2001 through 2008, with control for facility and market characteristics and secular trends. We found that increased CAMOD Medicaid HCBS spending at the local level is associated with decreased admissions of younger adults to nursing homes. Our findings suggest that states' efforts to expand HCBS for this population should continue.

No! Don't touch the toys : Preschoolers' discipline towards their younger siblings

NARCIS (Netherlands)

van Berkel, Sheila R.; Groeneveld, Marleen G.; Van der Pol, Lotte D.; Endendijk, Joyce; Hallers-Haalboom, Elizabeth T.; Bakermans-Kranenburg, Marian J.; Mesman, Judi

2017-01-01

Parental limit setting is a challenging and common situation in the daily lives of young children. During these situations, older siblings may use their more advanced cognitive skills and their greater physical strength to discipline their younger sibling and prevent or correct noncompliant

Using warnings to reduce categorical false memories in younger and older adults.

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Carmichael, Anna M; Gutchess, Angela H

2016-07-01

Warnings about memory errors can reduce their incidence, although past work has largely focused on associative memory errors. The current study sought to explore whether warnings could be tailored to specifically reduce false recall of categorical information in both younger and older populations. Before encoding word pairs designed to induce categorical false memories, half of the younger and older participants were warned to avoid committing these types of memory errors. Older adults who received a warning committed fewer categorical memory errors, as well as other types of semantic memory errors, than those who did not receive a warning. In contrast, young adults' memory errors did not differ for the warning versus no-warning groups. Our findings provide evidence for the effectiveness of warnings at reducing categorical memory errors in older adults, perhaps by supporting source monitoring, reduction in reliance on gist traces, or through effective metacognitive strategies.

Incidental memory of younger and older adults for objects encountered in a real world context.

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Xiaoyan Qin

Full Text Available Effects of context on the perception of, and incidental memory for, real-world objects have predominantly been investigated in younger individuals, under conditions involving a single static viewpoint. We examined the effects of prior object context and object familiarity on both older and younger adults' incidental memory for real objects encountered while they traversed a conference room. Recognition memory for context-typical and context-atypical objects was compared with a third group of unfamiliar objects that were not readily named and that had no strongly associated context. Both older and younger adults demonstrated a typicality effect, showing significantly lower 2-alternative-forced-choice recognition of context-typical than context-atypical objects; for these objects, the recognition of older adults either significantly exceeded, or numerically surpassed, that of younger adults. Testing-awareness elevated recognition but did not interact with age or with object type. Older adults showed significantly higher recognition for context-atypical objects than for unfamiliar objects that had no prior strongly associated context. The observation of a typicality effect in both age groups is consistent with preserved semantic schemata processing in aging. The incidental recognition advantage of older over younger adults for the context-typical and context-atypical objects may reflect aging-related differences in goal-related processing, with older adults under comparatively more novel circumstances being more likely to direct their attention to the external environment, or age-related differences in top-down effortful distraction regulation, with older individuals' attention more readily captured by salient objects in the environment. Older adults' reduced recognition of unfamiliar objects compared to context-atypical objects may reflect possible age differences in contextually driven expectancy violations. The latter finding underscores the

Impact of age-relevant goals on future thinking in younger and older adults.

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Lapp, Leann K; Spaniol, Julia

2017-10-01

This study investigated how personal goals influence age differences in episodic future thinking. Research suggests that personal goals change with age and like autobiographical memory, future thinking is thought to be organised and impacted by personal goals. It was hypothesised that cueing older adults with age-relevant goals should modulate age differences in episodic details and may also influence phenomenological characteristics of imagined scenarios. Healthy younger and older adults completed the Future Thinking Interview [Addis, D. R., Wong, A. T., & Schacter, D. L. (2008). Age-related changes in the episodic simulation of future events. Psychological Science, 19(1), 33-41. doi: 10.1111/j.1467-9280.2008.02043.x ] adapted to activate age-appropriate goals. Narratives were scored with an established protocol to obtain objective measures of episodic and semantic details. Subjective features such as emotionality and personal significance showed age differences as a function of goal domain while other features (e.g., vividness) were unaffected. However, consistent with prior reports, older adults produced fewer episodic details than younger adults and this was not modulated by goal domain. The results do not indicate that goal activation affects level of episodic detail. With respect to phenomenological aspects of future thinking, however, younger adults show more sensitivity to goal activation, compared with older adults.

Comparing Effects of Intrinsic and Extrinsic Social Values Between Younger and Older Employees.

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Yeung, Dannii Y; Fung, Helene H; Chan, Darius K-S

2016-08-17

Socioemotional selectivity theory proposes that older adults emphasize emotional goals and interpersonal closeness to a greater extent than do younger adults, suggesting that holding social work-related values (SWVs) may be beneficial to older employees. This project aimed at examining two dimensions of SWVs, intrinsic and extrinsic SWVs, and tested whether age and work situation would moderate their effects on self-rated job performance. A cross-sectional survey (Study 1, N = 357) and a 14-day experience sampling study (Study 2, N = 77) were conducted among Chinese managerial employees. Study 1 showed that the direct effect of intrinsic SWVs on self-rated job performance was stronger in older employees than in younger employees. Study 2 demonstrated that older employees who valued intrinsic SWVs while being in social situations performed much better than when they did not value intrinsic SWVs but being in social situations; however such positive effect was not shown in younger employees. Findings of this project reveal that the effect of SWVs varies across locus of effect (intrinsic versus extrinsic), age, and work situation. Among older employees, the positive effect of intrinsic SWVs is more crucial than that of extrinsic SWVs on self-rated job performance. Findings of this project imply that intrinsically rewarding incentives would be more effective in motivating older employees to reach peak performance.

Extra-terrestrial igneous granites and related rocks: A review of their occurrence and petrogenesis

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Bonin, Bernard

2012-11-01

The telluric planets and the asteroid belt display the same internal structure with a metallic inner core and a silicate outer shell. Experimental data and petrological evidence in silicate systems show that granite can be produced by extreme igneous differentiation through various types of igneous processes. On Moon, 4.4-3.9 Ga granite clasts display dry mineral assemblages. They correspond to at least 8 discrete intrusive events. Large K/Ca enrichment and low REE abundances in granite relative to KREEP are consistent with silicate liquid immiscibility, a process observed in melt inclusions within olivine of lunar basalts and in lunar meteorites. Steep-sided domes identified by remote sensing can represent intrusive or extrusive felsic formations. On Mars, black-and-white rhythmic layers observed on the Tharsis rise along the flanks of the peripheral scarps of the Tharsis Montes giant volcanoes suggest the possible eruption of felsic pyroclastites. Though no true granites were found so far in the Martian SNC meteorites, felsic glasses and mesostases were identified and a component close to terrestrial continental (granitic) crust is inferred from trace element and isotope systematics. Venus has suffered extensive volcanic resurfacing, whereas folded and faulted areas resemble terrestrial continents. Near large shield volcanoes, with dominant basaltic compositions, steep-sided domes have been interpreted as non-degassed silicic extrusions. The hypothesis of a granitic component is "tantalising". Extra-terrestrial granite is frequently found as clasts and mesostases in asteroidal meteorites. Porphyritic textures, with alkali feldspar crystals up to several centimetres in size, were observed in silicate enclaves within iron meteorites. In the chondrite clan, polymict breccias can contain granitic clasts, whose provenance is debated. One clast from the Adzhi-Bogdo meteorite yields a 4.53 ± 0.03 Ga Pb-Pb age, making it the oldest known granite in the solar system. The

Pieces of Other Worlds - Enhance YSS Education and Public Outreach Events with Extraterrestrial Samples

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Allen, C.

2010-12-01

During the Year of the Solar System spacecraft will encounter two comets; orbit the asteroid Vesta, continue to explore Mars with rovers, and launch robotic explorers to the Moon and Mars. We have pieces of all these worlds in our laboratories. Extensive information about these unique materials, as well as actual lunar samples and meteorites, is available for display and education. The Johnson Space Center (JSC) curates NASA's extraterrestrial samples to support research, education, and public outreach. At the current time JSC curates five types of extraterrestrial samples: Moon rocks and soils collected by the Apollo astronauts Meteorites collected on US expeditions to Antarctica (including rocks from the Moon, Mars, and many asteroids including Vesta) “Cosmic dust” (asteroid and comet particles) collected by high-altitude aircraft Solar wind atoms collected by the Genesis spacecraft Comet and interstellar dust particles collected by the Stardust spacecraft These rocks, soils, dust particles, and atoms continue to be studied intensively by scientists around the world. Descriptions of the samples, research results, thousands of photographs, and information on how to request research samples are on the JSC Curation website: http://curator.jsc.nasa.gov/ NASA is eager for scientists and the public to have access to these exciting samples through our various loan procedures. NASA provides a limited number of Moon rock samples for either short-term or long-term displays at museums, planetariums, expositions, and professional events that are open to the public. The JSC Public Affairs Office handles requests for such display samples. Requestors should apply in writing to Mr. Louis Parker, JSC Exhibits Manager. He will advise successful applicants regarding provisions for receipt, display, and return of the samples. All loans will be preceded by a signed loan agreement executed between NASA and the requestor's organization. Email address: louis.a.parker@nasa.gov Sets

WAYFINDING STUDY IN VIRTUAL ENVIRONMENTS: THE ELDERLY VS. THE YOUNGER-AGED GROUPS

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Seunghae Lee

2011-07-01

Full Text Available This study aims to examine the impact of architectural wayfinding aids on wayfinding performances in comparison of the elderly group and the younger aged group. An ambulatory healthcare facility was simulated using Virtual Reality (VR to develop two levels of wayfinding aids for the same environments. The base model included minimal wayfinding aids, and the design model included more wayfinding aids. The VR environment was presented in the form of video in order to test wayfinding performances at three different wayfinding decision points. Results showed that age and wayfinding aids impacted wayfinding performances. The younger-aged group performed wayfinding better compared to the elderly group. Participants who were tested in the design model were more successful in wayfinding compared to the elderly group. The elderly group reported that more salient wayfinding aids such as a big logo and paint colors helped their wayfinding while the younger-aged group reported less salient aids such as door designs as helpful wayfinding aids. When there were minimal wayfinding aids, the elderly participants needed to rely mostly on memory recall by remembering turns or paying close attention. When participants felt that the wayfinding test was difficult, their performances were less successful. Findings in this study suggest that wayfinding design for the elderly should consider the limited ability of recall and therefore, design wayfinding aids more frequently with more salient aids to avoid confusion. The elderly group needed to rely on their limited cognitive ability when there were not enough wayfinding aids, which make them experience difficulties in wayfinding.

Phoneme categorization and discrimination in younger and older adults: a comparative analysis of perceptual, lexical, and attentional factors.

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Mattys, Sven L; Scharenborg, Odette

2014-03-01

This study investigates the extent to which age-related language processing difficulties are due to a decline in sensory processes or to a deterioration of cognitive factors, specifically, attentional control. Two facets of attentional control were examined: inhibition of irrelevant information and divided attention. Younger and older adults were asked to categorize the initial phoneme of spoken syllables ("Was it m or n?"), trying to ignore the lexical status of the syllables. The phonemes were manipulated to range in eight steps from m to n. Participants also did a discrimination task on syllable pairs ("Were the initial sounds the same or different?"). Categorization and discrimination were performed under either divided attention (concurrent visual-search task) or focused attention (no visual task). The results showed that even when the younger and older adults were matched on their discrimination scores: (1) the older adults had more difficulty inhibiting lexical knowledge than did younger adults, (2) divided attention weakened lexical inhibition in both younger and older adults, and (3) divided attention impaired sound discrimination more in older than younger listeners. The results confirm the independent and combined contribution of sensory decline and deficit in attentional control to language processing difficulties associated with aging. The relative weight of these variables and their mechanisms of action are discussed in the context of theories of aging and language. (c) 2014 APA, all rights reserved.

Seemingly divergent sea surface temperature proxy records in the central Mediterranean during the last deglaciation

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M.-A. Sicre

2013-06-01

Full Text Available Sea surface temperatures (SSTs were reconstructed over the last 25 000 yr using alkenone paleothermometry and planktonic foraminifera assemblages from two cores of the central Mediterranean Sea: the MD04-2797 core (Siculo–Tunisian channel and the MD90-917 core (South Adriatic Sea. Comparison of the centennial scale structure of the two temperature signals during the last deglaciation period reveals significant differences in timing and amplitude. We suggest that seasonal changes likely account for seemingly proxy record divergences during abrupt transitions from glacial to interglacial climates and for the apparent short duration of the Younger Dryas (YD depicted by the alkenone time series, a feature that has already been stressed in earlier studies on the Mediterranean deglaciation.

Beliefs in advance care planning among Chinese Americans: Similarities and differences between the younger and older generations

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Mei Ching Lee

2017-10-01

Full Text Available The purpose of this research is to explore behavioral, normative, and control beliefs in the discussion of advance care planning (ACP among older and younger Chinese Americans. Ethnic minority groups have been identified as less engaged in ACP and this represents an ethnic and cultural gap. Older Chinese American adults often have different beliefs and values compared to the younger generation who are more acculturated to American mainstream culture. These differences may hinder the discussion of ACP with Chinese older adults. A qualitative design was used. The Theory of Planned Behavior guided the development of the interview guide. We recruited 60 Chinese Americans. Prior experience was identified as a theme that influenced attitudes about ACP. We found that older and younger Chinese participants had different beliefs in the norm and control related to ACP discussions, but not in the belief of attitudes about ACP discussions. Both younger and older Chinese American participants believed that ACP was important and necessary. Participants in both clusters expressed that they were ready and willing to engage in ACP discussions with their family members but hesitant to initiate these discussions. The reluctance in discussing ACP with Chinese older adults may be related to the expectations and obligations of Xiao (filial piety in Chinese culture. This study describes the similarities and differences of beliefs in ACP between older and younger Chinese Americans. We identified barriers and facilitators in behavioral, normative, and control beliefs that can be used to promote ACP for Chinese Americans.

Israeli Arabs develop diverticulitis at a younger age and are more likely to require surgery than Jews.

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Itai, Ghersin; Slijper, Nadav; Sroka, Gideon; Matter, Ibrahim

2015-01-01

Only few studies have examined the impact of racial differences on the age of onset, course and outcomes of diverticulitis. To provide data about the epidemiology of diverticulitis in northern Israel, and to determine whether ethnicity is a predictor of age of onset, complications, and need for surgery. Was conducted a retrospective review of the charts of all patients diagnosed with a first episode of diverticulitis in our hospital between 2005 and 2012. Were found 638 patients with a first episode of acute diverticulitis in the eight year interval. Israeli Arabs developed a first episode of diverticulitis at a younger age compared to Jews (51.2 vs 63.8 years, p<0.01). Arabs living in rural areas developed diverticulitis at a younger age than Arabs living in urban centers (49.4 vs 54.5 years, P=0.03). Jewish and Arabic men developed diverticulitis at younger age compared to their female counterparts (59.9 vs 66.09, p<0.01, and 47.31 vs 56.93, p<0.01, respectively). Arabs were more likely [odds ratio (OR)=1.81 ,95% confidence interval (CI)1.12-2.90, p=0.017] than Jews to require surgical treatment (urgent or elective) for diverticulitis. Israeli Arabs tend to develop diverticulitis at a younger age and are more likely to require surgical treatment for diverticulitis compared to Jews. Arabs living in rural areas develop diverticulitis at a younger age than Arabs living in urban centers. These findings highlight a need to address the root cause for ethnic differences in onset, course and outcome of acute diverticulitis.

AN OPPORTUNISTIC SEARCH FOR EXTRATERRESTRIAL INTELLIGENCE (SETI) WITH THE MURCHISON WIDEFIELD ARRAY

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Tingay, S. J.; Tremblay, C.; Walsh, A.; Urquhart, R. [International Centre for Radio Astronomy Research (ICRAR), Curtin University, Bentley, WA 6102 (Australia)

2016-08-20

A spectral line image cube generated from 115 minutes of MWA data that covers a field of view of 400 sq, deg. around the Galactic Center is used to perform the first Search for ExtraTerrestrial Intelligence (SETI) with the Murchison Widefield Array (MWA). Our work constitutes the first modern SETI experiment at low radio frequencies, here between 103 and 133 MHz, paving the way for large-scale searches with the MWA and, in the future, the low-frequency Square Kilometre Array. Limits of a few hundred mJy beam{sup −1} for narrowband emission (10 kHz) are derived from our data, across our 400 sq. deg. field of view. Within this field, 45 exoplanets in 38 planetary systems are known. We extract spectra at the locations of these systems from our image cube to place limits on the presence of narrow line emission from these systems. We then derive minimum isotropic transmitter powers for these exoplanets; a small handful of the closest objects (10 s of pc) yield our best limits of order 10{sup 14} W (Equivalent Isotropic Radiated Power). These limits lie above the highest power directional transmitters near these frequencies currently operational on Earth. A SETI experiment with the MWA covering the full accessible sky and its full frequency range would require approximately one month of observing time. The MWA frequency range, its southern hemisphere location on an extraordinarily radio quiet site, its very large field of view, and its high sensitivity make it a unique facility for SETI.

Cold Reversal on Kodiak Island, Alaska, Correlated with the European Younger Dryas by Using Variations of Atmospheric C-14 Content

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Hajdas, Irka; Bonani, Georges; Boden, Per; Peteet, Dorothy M.; Mann, Daniel H.

1999-01-01

High-resolution AMS (accelerator-mass-spectrometer) radiocarbon dating was performed on late-glacial macrofossils in lake sediments from Kodiak Island, Alaska, and on shells in marine sediments from southwest Sweden. In both records, a dramatic drop in radiocarbon ages equivalent to a rise in the atmospheric C-14 by approximately 70%. coincides with the beginning of the cold period at 11000 yr B.P. (C-14 age). Thus our results show that a close correlation between climatic records around the globe is possible by using a global signature of changes in atmospheric C-14 content.

Memory for staged events: Supporting older and younger adults' memory with SenseCam.

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Mair, Ali; Poirier, Marie; Conway, Martin A

2018-03-01

Two experiments measured the effect of retrieval support provided by a wearable camera, SenseCam, on older and younger adults' memory for a recently experienced complex staged event. In each experiment, participants completed a series of tasks in groups, and the events were recalled 2 weeks later, after viewing SenseCam images (experimental condition) or thinking about the event (control condition). When IQ and education were matched, young adults recalled more event details than older adults, demonstrating an age-related deficit for novel autobiographical material. Reviewing SenseCam images increased the number of details recalled by older and younger adults, and the effect was similar for both groups. These results suggest that memory can be supported by the use of SenseCam, but the age-related deficit is not eliminated.

The relationship between need for closure and memory for schema-related information among younger and older adults.

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Kossowska, Małgorzata; Jaśko, Katarzyna; Bar-Tal, Yoram; Szastok, Marta

2012-01-01

Two studies were conducted to examine the relationships among need for closure (NFC) and schematic information processing in younger and older adults. The results show increased NFC to be associated with less schematic processing (i.e., less memory for schema-consistent items, and more memory for schema-irrelevant items, out of all items memorized correctly), among older than younger adults. The findings of the studies are interpreted as demonstrating the age-associated deficit in information processing consistent with the level of NFC. Moreover, the results indicate that positive mood may play a role in facilitating information processing consistent with the level of NFC among older and younger adults. Finally, we present a framework for predicting when older adults will and will not effectively use schematic processing, considered a compensatory strategy for decline in cognitive abilities.

Impacts of suppression on emotional responses and performance outcomes: an experience-sampling study in younger and older workers.

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Yeung, Dannii Y; Fung, Helene H

2012-11-01

Past studies have demonstrated that older adults used less emotional suppression to regulate their emotions than did younger adults, but the effectiveness of using this emotion regulatory strategy on psychosocial well-being across age remains largely unexplored. The present study adopted an experience-sampling method to examine whether the impacts of momentary employment of emotional suppression on momentary positive and negative emotions and job performance would be different by age. Eighty-seven Chinese insurance workers, aged between 18 and 61 years, participated in a 5-day sampling study. Their affective responses at work, momentary task performance, and sales productivity were recorded. Results showed that older workers' greater use of suppression at work was associated with lower intensity of negative emotions, whereas such association was not found among younger workers. Moreover, greater use of suppression over the sampling period was significantly predictive of sales productivity of older workers, but such a positive association was not shown in younger workers. These findings reveal that the use of suppression at work may be more effective for older workers than for younger workers.

Cross-Sectional Analysis of Per Capita Supply of Doctors of Chiropractic and Opioid Use in Younger Medicare Beneficiaries.

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Weeks, William B; Goertz, Christine M

2016-05-01

The purpose of this study was to determine whether the per-capita supply of doctors of chiropractic (DCs) or Medicare spending on chiropractic care was associated with opioid use among younger, disabled Medicare beneficiaries. Using 2011 data, at the hospital referral region level, we correlated the per-capita supply of DCs and spending on chiropractic manipulative therapy (CMT) with several measures of per-capita opioid use by younger, disabled Medicare beneficiaries. Per-capita supply of DCs and spending on CMT were strongly inversely correlated with the percentage of younger Medicare beneficiaries who had at least 1, as well as with 6 or more, opioid prescription fills. Neither measure was correlated with mean daily morphine equivalents per opioid user or per chronic opioid user. A higher per-capita supply of DCs and Medicare spending on CMT were inversely associated with younger, disabled Medicare beneficiaries obtaining an opioid prescription. However, neither measure was associated with opioid dosage among patients who obtained opioid prescriptions. Copyright © 2016. Published by Elsevier Inc.

Food consumption of children younger than 6 years according to the degree of food processing

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Ediana Volz Neitzke Karnopp

Full Text Available Abstract: Objective: To evaluate food intake according to the degree of processing, stratified by family income and age, in a representative sample of children younger than 6 years in the city of Pelotas, RS, Brazil. Methods: Cross-sectional population-based study carried out with 770 children aged 0-72 months of age living in the urban area of Pelotas. The dietary intake of children was assessed by 24-h recall administered to mothers or guardians. The energy intake was estimated and each food item was classified according to the food processing degree. Food consumption was stratified by age (younger than 24 months; 24 months or older and associations between quintiles of family income and relative contribution of each food to total energy were performed by linear regression. The Wald test was applied to test linear trend across groups. Results: The mean energy intake was 1725.7 kcal/day. The mean contribution of processed and ultraprocessed foods was 19.7% among children younger than 24 months and 37% in those aged 24 months or older, while the mean consumption of natural and minimally processed food was 61% and 44%, respectively. Among children aged 24 months or older, a greater consumption of canned foods, cheese and sweets was observed as family income quintiles increased, while breads were more consumed by those children belonging to the lower income quintiles. Conclusion: A high caloric contribution of ultraprocessed foods in detriment to a lower consumption of natural and minimally processed foods was observed in the diet of children younger than 6 years.

Superior recognition performance for happy masked and unmasked faces in both younger and older adults.

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Joakim eSvard

2012-11-01

Full Text Available In the aging literature it has been shown that even though emotion recognition performance decreases with age, the decrease is less for happiness than other facial expressions. Studies in younger adults have also revealed that happy faces are more strongly attended to and better recognized than other emotional facial expressions. Thus, there might be a more age independent happy face advantage in facial expression recognition. By using a backward masking paradigm and varying stimulus onset asynchronies (17–267 ms the temporal development of a happy face advantage, on a continuum from low to high levels of visibility, was examined in younger and older adults. Results showed that across age groups, recognition performance for happy faces was better than for neutral and fearful faces at durations longer than 50 ms. Importantly, the results showed a happy face advantage already during early processing of emotional faces in both younger and older adults. This advantage is discussed in terms of processing of salient perceptual features and elaborative processing of the happy face. We also investigate the combined effect of age and neuroticism on emotional face processing. The rationale was previous findings of age related differences in physiological arousal to emotional pictures and a relation between arousal and neuroticism. Across all durations, there was an interaction between age and neuroticism, showing that being high in neuroticism might be disadvantageous for younger, but not older adults’ emotion recognition performance during arousal enhancing tasks. These results indicate that there is a relation between aging, neuroticism, and performance, potentially related to physiological arousal.

Pharmacokinetics and effect on the corrected QT interval of single-dose escitalopram in healthy elderly compared with younger adults.

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Chung, Hyewon; Kim, Anhye; Lim, Kyoung Soo; Park, Sang-In; Yu, Kyung-Sang; Yoon, Seo Hyun; Cho, Joo-Youn; Chung, Jae-Yong

2017-01-01

Escitalopram is the (S)-enantiomer of citalopram that has a potential QT prolonging effect. In this study, 12 healthy elderly individuals received a single oral dose of escitalopram (20 mg), and their pharmacokinetics and QT effect data were compared with data from 33 younger adults obtained in a previous study. Serial blood samples for pharmacokinetic analysis were collected and ECG was performed up to 48 h postdose. The elderly and younger adults showed similar pharmacokinetic profiles. The geometric mean ratios (90% confidence interval) of the elderly compared with the younger adults were 1.02 (0.89-1.17) and 1.01 (0.86-1.17) for the maximum plasma concentration and area under the concentration-time curve, respectively. The mean baseline-adjusted QT (dQT) time profiles were similar and the mean values of maximum dQT were not significantly different between the elderly and the younger adults. The linear mixed-effect model indicated a weak but positive relationship between the escitalopram concentration and dQT, with an estimated coefficient of concentration of 0.43-0.54. In conclusion, the pharmacokinetics and QT effect of a single dose of escitalopram observed in the elderly without comorbidities and younger adults were generally similar.

Family Caregivers' Experiences of Caring for a Relative With Younger Onset Dementia: A Qualitative Systematic Review.

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Cabote, Christy Joy; Bramble, Marguerite; McCann, Damhnat

2015-08-01

Family caregiving for people with younger onset dementia affects everyone in the family unit. This article presents findings of a qualitative systematic review exploring the experiences of family caregivers of persons with younger onset dementia. A systematic search resulted in the inclusion of five relevant articles, and two groups within the family unit were identified-child caregivers and adult and spousal caregivers. Using the thematic synthesis approach, five themes emerged: dementia damage, grief for loss of relationship, changes in family roles, positive and negative impacts of family caregiving, and transition to formal care. The review findings support increasing evidence that despite the stress of caring for a person with dementia damage, family members have the capacity to cope, adapt, and grow through their experiences. Nurses can assist families to identify their unique strengths and enhance family resiliency so they can navigate the "lonely road" of younger onset dementia. © The Author(s) 2015.

The limits of extremophilic life expanded under extraterrestrial environment-simulated experiments

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Lage, C.; Dalmaso, G.; Teixeira, L.; Bendia, A.; Rosado, A.

2012-09-01

Astrobiology is a brand new area of science that seeks to understand the origin and dynamics of life in the universe. Several hypotheses to explain life in the cosmic context have been developed throughout human history, but only now technology has allowed many of them to be tested. Laboratory experiments have been able to show how chemical elements essential to life, carbon, nitrogen, oxygen and hydrogen combine in biologically important compounds. Interestingly, these compounds are found universally. As these compounds were combined to the point of originating cells and complex organisms is still a challenge to be unveiled by science. However, our 4.5 billion years-old solar system was born within a 10-billion years-old universe. Thus, simple cells like microorganisms may have had time to form in planets older than ours or other suitable molecular places in the universe. One hypothesis to explain the origin of life on Earth is called panspermia, which predicts that microbial life could have been formed in the universe billions of years ago, traveling between planets, and inseminating units of life that could have become more complex in habitable planets like ours. A project designed to test the viability of extremophile microorganisms exposed to simulated extraterrestrial environments is ongoing at the Carlos Chagas Filho Institute of Biophysics to test whether microbial life could withstand those inhospitable environments. Ultra-resistant (known or novel ones) microorganisms collected from terrestrial extreme environments, extremophiles, have been exposed to intense radiation sources simulating solar radiation (at synchrotron accelerators), capable of emitting in a few hours radiation equivalent of million years accumulated doses. The results obtained in these experiments reveal the interesting possibility of the existence of microbial life beyond Earth.

Cannabis use patterns and motives: A comparison of younger, middle-aged, and older medical cannabis dispensary patients.

Science.gov (United States)

Haug, Nancy A; Padula, Claudia B; Sottile, James E; Vandrey, Ryan; Heinz, Adrienne J; Bonn-Miller, Marcel O

2017-09-01

Medical cannabis is increasingly being used for a variety of health conditions as more states implement legislation permitting medical use of cannabis. Little is known about medical cannabis use patterns and motives among adults across the lifespan. The present study examined data collected at a medical cannabis dispensary in San Francisco, California. Participants included 217 medical cannabis patients who were grouped into age-defined cohorts (younger: 18-30, middle-aged: 31-50, and older: 51-72). The age groups were compared on several measures of cannabis use, motives and medical conditions using one-way ANOVAs, chi-square tests and linear regression analyses. All three age groups had similar frequency of cannabis use over the past month; however, the quantity of cannabis used and rates of problematic cannabis use were higher among younger users relative to middle-aged and older adults. The association between age and problematic cannabis use was moderated by age of regular use initiation such that earlier age of regular cannabis use onset was associated with more problematic use in the younger users, but not among older users. Middle-aged adults were more likely to report using medical cannabis for insomnia, while older adults were more likely to use medical cannabis for chronic medical problems such as cancer, glaucoma and HIV/AIDS. Younger participants reported cannabis use when bored at a greater rate than middle-aged and older adults. Findings suggest that there is an age-related risk for problematic cannabis use among medical cannabis users, such that younger users should be monitored for cannabis use patterns that may lead to deleterious consequences. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cannabis Use Patterns and Motives: A Comparison of Younger, Middle-Aged, and Older Medical Cannabis Dispensary Patients

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Haug, Nancy A.; Padula, Claudia B.; Sottile, James E.; Vandrey, Ryan; Heinz, Adrienne J.; Bonn-Miller, Marcel O.

2017-01-01

Introduction Medical cannabis is increasingly being used for a variety of health conditions as more states implement legislation permitting medical use of cannabis. Little is known about medical cannabis use patterns and motives among adults across the lifespan. Methods The present study examined data collected at a medical cannabis dispensary in San Francisco, California. Participants included 217 medical cannabis patients who were grouped into age-defined cohorts (younger: 18–30, middle-aged: 31–50, and older: 51–72). The age groups were compared on several measures of cannabis use, motives and medical conditions using one-way ANOVAs, chi-square tests and linear regression analyses. Results All three age groups had similar frequency of cannabis use over the past month; however, the quantity of cannabis used and rates of problematic cannabis use were higher among younger users relative to middle-aged and older adults. The association between age and problematic cannabis use was moderated by age of regular use initiation such that earlier age of regular cannabis use onset was associated with more problematic use in the younger users, but not among older users. Middle-aged adults were more likely to report using medical cannabis for insomnia, while older adults were more likely to use medical cannabis for chronic medical problems such as cancer, glaucoma and HIV/AIDS. Younger participants reported cannabis use when bored at a greater rate than middle-aged and older adults. Conclusions Findings suggest that there is an age-related risk for problematic cannabis use among medical cannabis users, such that younger users should be monitored for cannabis use patterns that may lead to deleterious consequences. PMID:28340421

The observation of curative effects by therapy with low-dose 131I in younger with Graves' disease

International Nuclear Information System (INIS)

Cui Liqun; Li Lingling; Zhang Chenggang

2007-01-01

Objective: To observe the the curative effects in younger with Graves disease therapied by 131 I. Methods: The dose of 131 I is administrated with 1480-2220kBq/g of thyroid tissue which was decided by many factors that include the paticnt's Age, volume of thyroid, course and if antihyroid drug is administrated. The curative effects was classfide into four groups: complete remission, excellence, parts of remission, no effect. Results: 47 were complete remission, 34 were excellence, 10 were the parts of remission and 0 was no effects. The total effective power was 100%. Conclusions: Therapy with low-dose of mi for younger with Graves' disease is an effect, simple and safe method. Repeating treatment with 131 I will improve the curative rate of Graves' disease in younger, and the incidence of hypothyroidism cannot be increased. (authors)

Five years of Project META - An all-sky narrow-band radio search for extraterrestrial signals

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Horowitz, Paul; Sagan, Carl

1993-01-01

We have conducted a five-year search of the northern sky (delta between 30 and 60 deg) for narrow-band radio signals near the 1420 MHz line of neutral hydrogen, and its second harmonic, using an 8.4 x 10 exp 6 channel Fourier spectrometer of 0.05 Hz resolution and 400 kHz instantaneous bandwidth. The observing frequency was corrected both for motions with respect to three astronomical inertial frames, and for the effect of Earth's rotation, which provides a characteristic changing Doppler signature for narrow-band signals of extraterrestrial origin. Among the 6 x 10 exp 13 spectral channels searched, we have found 37 candidate events exceeding the average detection threshold of 1.7 x 10 exp -23 W/sq m, none of which was detected upon reobservation. The strongest of these appear to be dominated by rare processor errors. However, the strongest signals that survive culling for terrestrial interference lie in or near the Galactic plane. We describe the search and candidate events, and set limits on the prevalence of supercivilizations transmitting Doppler-precompensated beacons at H I or its second harmonic. We conclude with recommendations for future searches, based upon these findings, and a description of our next-generation search system.

Organizational age cultures: The interplay of chief executive officers age and attitudes toward younger and older employees

OpenAIRE

Zacher, Hannes; Gielnik, Michael

2014-01-01

This article investigates the interactive effects of chief executive officer (CEO) age and CEO attitudes toward younger and older employees on organisational age cultures. Data was collected from 66 CEOs of small and medium-sized businesses and 274 employees. Results were consistent with expectations based on organisational culture and upper echelons theories. The relationship between CEO age and organisational age culture for younger employees was negative for CEOs with a less positive attit...

Motivating Millennials: Improving Practices in Recruiting, Retaining, and Motivating Younger Library Staff

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Smith, Sara D.; Galbraith, Quinn

2012-01-01

Working with younger staff and student employees can be a challenge for library supervisors in a multigenerational workplace. Because members of the Millennial Generation have different work expectations, managers need to adjust to best meet their needs. By surveying its five hundred student employees, Brigham Young University's Harold B. Lee…

Hyperbilirubinemia with urinary tract infection in infants younger than eight weeks old

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Hung-Ta Chen

2011-04-01

Conclusion: The incidence of UTI in the admitted infants with hyperbilirubinemia was as high as approximately 5.5%. The most common cultured bacterium in urine was E coli. Therefore, performing urinary tests to exclude the possibility of coincidental UTI may be necessary for admitted jaundiced infants younger than 8 weeks old.

Listening Effort in Younger and Older Adults: A Comparison of Auditory-Only and Auditory-Visual Presentations.

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Sommers, Mitchell S; Phelps, Damian

2016-01-01

One goal of the present study was to establish whether providing younger and older adults with visual speech information (both seeing and hearing a talker compared with listening alone) would reduce listening effort for understanding speech in noise. In addition, we used an individual differences approach to assess whether changes in listening effort were related to changes in visual enhancement-the improvement in speech understanding in going from an auditory-only (A-only) to an auditory-visual condition (AV) condition. To compare word recognition in A-only and AV modalities, younger and older adults identified words in both A-only and AV conditions in the presence of six-talker babble. Listening effort was assessed using a modified version of a serial recall task. Participants heard (A-only) or saw and heard (AV) a talker producing individual words without background noise. List presentation was stopped randomly and participants were then asked to repeat the last three words that were presented. Listening effort was assessed using recall performance in the two- and three-back positions. Younger, but not older, adults exhibited reduced listening effort as indexed by greater recall in the two- and three-back positions for the AV compared with the A-only presentations. For younger, but not older adults, changes in performance from the A-only to the AV condition were moderately correlated with visual enhancement. Results are discussed within a limited-resource model of both A-only and AV speech perception.

Low Levels of Dehydroepiandrosterone Sulfate in Younger Burnout Patients.

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Anna-Karin Lennartsson

Full Text Available Dehydroepiandrosterone sulphate (DHEA-s is an anabolic protective hormone of importance for maintenance of health. DHEA-s levels peak in young adults and decline thereafter with age. DHEA-s has previously been shown to be lower in individuals reporting prolonged stress. This study investigates DHEA-s levels in patients with clinical burnout, a disorder caused by long-term psychosocial stress.122 patients (51% men and 47 controls (51% men in the age 25-54 years were included in the study. DHEA-s levels were compared between patients and controls in the whole sample and within each of the three 10-year-interval age groups.In the youngest age group (25-34 years, DHEA-s levels were on average 25% lower in the patients (p = 0.006. The differences in DHEA-s levels between patients and controls were more pronounced among female than male participants (on average 32% and 13% lower, respectively. There were no differences in DHEA-s levels between patients and controls in the age group 35-44 years (p = 0.927 or 45-54 years (p = 0.897 or when analyzing all age groups together (p = 0.187.The study indicates that levels of the health promoting "youth" hormone DHEA-s are low in younger burnout patients. The fact that younger adults have much higher DHEA-s levels and more pronounced inter-subject variability in DHEA-s levels than older individuals might explain why burnout status differentiates patients from controls only among the youngest patients included in this study.

Characteristics of Emergency Department Visits by Older Versus Younger Homeless Adults in the United States

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Steinman, Michael A.

2013-01-01

Objectives. We compared the characteristics of emergency department (ED) visits of older versus younger homeless adults. Methods. We analyzed 2005–2009 data from the National Hospital Ambulatory Medical Care Survey, a nationally representative survey of visits to hospitals and EDs, and used sampling weights, strata, and clustering variables to obtain nationally representative estimates. Results. The ED visits of homeless adults aged 50 years and older accounted for 36% of annual visits by homeless patients. Although demographic characteristics of ED visits were similar in older and younger homeless adults, clinical and health services characteristics differed. Older homeless adults had fewer discharge diagnoses related to psychiatric conditions (10% vs 20%; P = .002) and drug abuse (7% vs 15%; P = .003) but more diagnoses related to alcohol abuse (31% vs 23%; P = .03) and were more likely to arrive by ambulance (48% vs 36%; P = .02) and to be admitted to the hospital (20% vs 11%; P = .003). Conclusions. Older homeless adults’ patterns of ED care differ from those of younger homeless adults. Health care systems need to account for these differences to meet the needs of the aging homeless population. PMID:23597348

Managing hypercholesterolemia and preventing cardiovascular events in elderly and younger Chinese adults: focus on rosuvastatin

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Wang Z

2013-12-01

Full Text Available Zhen Wang, Junbo GeDepartment of Cardiology, Zhongshan Hospital, Shanghai, People's Republic of ChinaAbstract: Coronary heart disease (CHD is the leading cause of death worldwide. The efficacy and safety of statins in primary and secondary prevention of CHD is confirmed in several large studies, and rosuvastatin is the latest statin on market. We review the published literature on rosuvastatin in Chinese people. The pharmacokinetics of rosuvastatin in Chinese is somewhat different from that in Caucasians, but this does not influence the linear relationship between dosage and efficacy and with no drug accumulation. Rosuvastatin 5–20 mg/day is effective and safe in decreasing low-density lipoprotein cholesterol in both younger and elderly patients with hypercholesterolemia, even in very elderly patients. Rosuvastatin also shows anti-inflammatory and antiatherosclerosis features, such as reducing carotid intima-media thickness and plaque area. Rosuvastatin can also improve the prognosis of Chinese CHD patients, such as in the case of acute myocardial infarction. Its adverse-event rate is low and comparable to other statins. In conclusion, rosuvastatin is effective and safe for younger or elderly Chinese patients.Keywords: rosuvastatin, Chinese, younger, elderly

Elevated False Recollection of Emotional Pictures in Younger and Older Adults

OpenAIRE

Gallo, David A.; Foster, Katherine T.; Johnson, Elizabeth L.

2009-01-01

Current theories predict opposing effects of emotionally arousing information on false memory. If emotion enhances recollection, then false recollection might be lower for emotional compared to neutral pictures. However, if emotion enhances conceptual relatedness, then false recollection might increase for nonstudied but emotionally related pictures. We contrasted these two factors in younger and older adults, using the International Affective Pictures set. Although both age groups used recol...

The pediatric athlete: younger athletes with sport-related concussion.

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Meehan, William P; Taylor, Alex M; Proctor, Mark

2011-01-01

Although much of the lay media attention surrounding sport-related concussion (SRC) focuses on professional athletes, SRC is a common injury in pediatric sports. The anatomy, biomechanics, and response to injury of the developing pediatric brain differ from those of the adult. Similarly, the neurocognitive abilities of the child are developing more rapidly than in an adult. The effects of concussive brain injury on the life of a child are different from those of an adult. This article focuses on the aspects of SRC that are specific to the younger athletes. Copyright © 2011 Elsevier Inc. All rights reserved.

Acute atomoxetine treatment of younger and older children with ADHD: A meta-analysis of tolerability and efficacy

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Vaughan Brigette S

2008-09-01

Full Text Available Abstract Background Atomoxetine is FDA-approved as a treatment of attention-deficit/hyperactivity disorder (ADHD in patients aged 6 years to adult. Among pediatric clinical trials of atomoxetine to date, six with a randomized, double-blind, placebo-controlled design were used in this meta-analysis. The purpose of this article is to describe and compare the treatment response and tolerability of atomoxetine between younger children (6–7 years and older children (8–12 years with ADHD, as reported in these six acute treatment trials. Methods Data from six clinical trials of 6–9 weeks duration were pooled, yielding 280 subjects, ages 6–7 years, and 860 subjects, ages 8–12 years with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV-diagnosed ADHD. Efficacy was analyzed using the ADHD Rating Scale-IV (ADHD-RS, Conners' Parent Rating Scale-revised (CPRS-R:S, and the Clinical Global Impression of ADHD Severity (CGI-ADHD-S. Results Atomoxetine was superior to placebo in both age categories for mean (SD change in ADHD-RS total, total T, and subscale scores; 3 CPRS-R:S subscales; and CGI-ADHD-S from baseline. Although there were no significant treatment differentials between the age groups for these efficacy measures, the age groups themselves, regardless of treatment, were significantly different for ADHD-RS total (younger: ATX = -14.2 [13.8], PBO = -4.6 [10.4]; older: ATX = -15.4 [13.2], PBO = -7.3 [12.0]; p = .001, total T (younger: ATX = -15.2 [14.8], PBO = -4.9 [11.2]; older: ATX = -16.4 [14.6], PBO = -7.9 [13.1]; p = .003, and subscale scores (Inattentive: younger: ATX = -7.2 [7.5], PBO = -2.4 [5.7]; older: ATX = -8.0 [7.4], PBO = -3.9 [6.7]; p = .043; Hyperactive/Impulsive: younger: ATX = -7.0 [7.2], PBO = -2.1 [5.4]; older: ATX = -7.3 [7.0], PBO = -3.4 [6.3]; p Conclusion Atomoxetine is an effective and generally well-tolerated treatment of ADHD in both younger and older children as assessed by three

Venusians: the Planet Venus in the 18th-Century Extraterrestrial Life Debate

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Duner, David

2013-05-01

In the seventeenth and eighteenth centuries it became possible to believe in the existence of life on other planets on scientific grounds. Once the Earth was no longer the center of the universe according to Copernicus, once Galileo had aimed his telescope at the Moon and found it a rough globe with mountains and seas, the assumption of life on other planets became much less far-fetched. In general there were no actual differences between Earth and Venus, since both planets orbited the Sun, were of similar size, and possessed mountains and an atmosphere. If there is life on Earth, one may ponder why it could not also exist on Venus. In the extraterrestrial life debate of the seventeenth and eighteenth centuries, the Moon, our closest celestial body, was the prime candidate for life on other worlds, although a number of scientists and scholars also speculated about life on Venus and on other planets, both within our solar system and beyond its frontiers. This chapter discusses the arguments for life on Venus and those scientific findings that were used to support them, which were based in particular on assumptions and claims that both mountains and an atmosphere had been found on Venus. The transits of Venus in the 1760s became especially important for the notion that life could thrive on Venus. Here, I detect two significant cognitive processes that were at work in the search for life on Venus, i.e., analogical reasoning and epistemic perception, while analogies and interpretations of sensory impressions based on prior knowledge played an important role in astrobiological theories.

Improving ROLO lunar albedo model using PLEIADES-HR satellites extra-terrestrial observations

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Meygret, Aimé; Blanchet, Gwendoline; Colzy, Stéphane; Gross-Colzy, Lydwine

2017-09-01

The accurate on orbit radiometric calibration of optical sensors has become a challenge for space agencies which have developed different technics involving on-board calibration systems, ground targets or extra-terrestrial targets. The combination of different approaches and targets is recommended whenever possible and necessary to reach or demonstrate a high accuracy. Among these calibration targets, the moon is widely used through the well-known ROLO (RObotic Lunar Observatory) model developed by USGS. A great and worldwide recognized work was done to characterize the moon albedo which is very stable. However the more and more demanding needs for calibration accuracy have reached the limitations of the model. This paper deals with two mains limitations: the residual error when modelling the phase angle dependency and the absolute accuracy of the model which is no more acceptable for the on orbit calibration of radiometers. Thanks to PLEIADES high resolution satellites agility, a significant data base of moon and stars images was acquired, allowing to show the limitations of ROLO model and to characterize the errors. The phase angle residual dependency is modelled using PLEIADES 1B images acquired for different quasi-complete moon cycles with a phase angle varying by less than 1°. The absolute albedo residual error is modelled using PLEIADES 1A images taken over stars and the moon. The accurate knowledge of the stars spectral irradiance is transferred to the moon spectral albedo using the satellite as a transfer radiometer. This paper describes the data set used, the ROLO model residual errors and their modelling, the quality of the proposed correction and show some calibration results using this improved model.

Memory, priority encoding, and overcoming high-value proactive interference in younger and older adults.

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Friedman, Michael C; Castel, Alan D

2013-01-01

It is often necessary to remember important information while directing attention away from encoding less valuable information. To examine how aging influences the ability to control and update the encoding of high-value information, younger and older adults studied six lists of words that varied in terms of the point values associated with each word. The words were paired with the same high and low point values for three study-test cycles, but on the fourth and subsequent cycles the value-word pairings were switched such that the lowest value pairs became the highest values (and vice versa). For the first three study-test cycles, younger adults outperformed older adults in terms of the number of words recalled and overall point totals, but performance was similar in terms of selectively remembering high-value words. When the values were switched, both groups displayed substantial interference from the previous pairings. Although both groups improved with additional study-test cycles, only younger adults were able to fully recover from the interference effects. A similar, and more pronounced, set of results were obtained when positive and negative point values were paired with the words. The findings are interpreted in a value-directed remembering framework, emphasizing the role of benefits and costs of strategic encoding and age-related differences in the effects of interference on memory.

Distinctive Risk Factors and Phenotype of Younger Patients With Resistant Hypertension: Age Is Relevant.

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Ghazi, Lama; Oparil, Suzanne; Calhoun, David A; Lin, Chee Paul; Dudenbostel, Tanja

2017-05-01

Resistant hypertension, defined as blood pressure >140/90 mm Hg despite using ≥3 antihypertensive medications, is a well-recognized clinical entity. Patients with resistant hypertension are at an increased risk of cardiovascular disease compared with those with more easily controlled hypertension. Coronary heart disease mortality rates of younger adults are stagnating or on the rise. The purpose of our study was to characterize the phenotype and risk factors of younger patients with resistant hypertension, given the dearth of data on cardiovascular risk profile in this cohort. We conducted a cross-sectional analysis with predefined age groups of a large, ethnically diverse cohort of 2170 patients referred to the Hypertension Clinic at the University of Alabama at Birmingham. Patients (n=2068) met the inclusion criteria and were classified by age groups, that is, ≤40 years (12.7% of total cohort), 41 to 55 years (32.1%), 56 to 70 years (36.1%), and ≥71 years (19.1%). Patients aged ≤40 years compared with those aged ≥71 years had significantly earlier onset of hypertension (24.7±7.4 versus 55.0±14.1 years; P hypertension, younger individuals have a distinct phenotype characterized by overlapping risk factors and comorbidities, including obesity, high aldosterone, and high dietary sodium intake compared with elderly. © 2017 American Heart Association, Inc.

Physicians' response to sexual dysfunction presented by a younger vs. An older adult.

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Gewirtz-Meydan, Ateret; Ayalon, Liat

2017-12-01

The aim of this study is to determine whether physicians have an age bias regarding sexual dysfunction presented by older vs. younger patients in terms of attributed diagnosis, etiology, proposed treatment and perceived prognosis. An on-line survey consisting of one of two, randomly administered, case vignettes, which differed only by the age of the patient (28 or 78). In both cases, the patient was described as suffering from occasional erectile dysfunction with a clear psychosocial indication. A total of 236 physicians responded to the survey. Overall, 110 physicians received an "old" vignette and 126 physicians received a "young" vignette. Even though both cases presented with a clear psychosocial etiology, the "older" vignette was more likely to be diagnosed with erectile dysfunction whereas the "younger" vignette was more likely to be diagnosed with performance anxiety. The "older" vignette's dysfunction was more likely to be attributed to hormonal changes, health problems and decreased sexual desire. Physicians were more likely to recommend testosterone replacement therapy (TRT) and PDE5 inhibitors (PDE5i; such as Sildenafil; Vardenafil; Tadalafil) as well as a referral to urology to the "older" vignette. In contrast, the "younger" vignette was more often referred to a sexologist and received a more positive prognosis than the older patient. This study demonstrates an age bias among physicians regarding sexuality in later life. Of particular note is the tendency to prescribe PDE5i to the older patient, despite the clear psychosocial indication presented in the case vignette. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Supplementary home biofeedback improves quality of life in younger patients with fecal incontinence.

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Bartlett, Lynne; Sloots, Kathryn; Nowak, Madeleine; Ho, Yik-Hong

2015-01-01

Biofeedback is a scarce, resource-intensive clinical therapy. It is used to treat patients with bowel problems, including fecal incontinence (FI), who fail to respond to simple dietary advice, medication, or pelvic floor exercises. Populations are aging and younger cohorts use technology in managing their health, affording FI self-management opportunities. Does supplementary home-based biofeedback improve FI and quality of life (QOL)? Seventy-five incontinent participants (12 male), mean age 61.1 years, consented to participate. Thirty-nine patients (5 male) were randomized to the standard biofeedback protocol plus daily home use of a Peritron perineometer (intervention) and 36 patients (7 male) to the standard biofeedback protocol (control). On completion of the study each perineometer exercise session was rated for technique by 2 raters, blinded to the patient and order of sessions. With the exception of Fecal Incontinence Quality of Life Scale lifestyle improvement (intervention--9.1% vs. controls--0.3%, P=0.026) and embarrassment improvement (intervention--50.0% vs. controls--18.3%, P=0.026), supplementary home biofeedback did not result in greater clinical improvement for the intervention group as a whole. However, on stratification around the mean age, continence and QOL of younger people in the intervention group were significantly better than those of their control counterparts. Graphed perineometer sessions demonstrated high compliance and improvement in exercise technique. Perineometers provided reassurance, motivation, and an exercise reminder ensuring that confidence was achieved quickly. Home biofeedback was acceptable and well tolerated by all users. Younger participants significantly benefited from using this technology.

The role of play in pre-school and younger school age children

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Kopas-Vukašinović Emina

2006-01-01

Full Text Available The paper deals with the importance of play for children’s development and learning in institutionalized preschool education, as well as the opportunities it provides concerning the organization of teaching activities with younger school age children. The paper is based on the theoretical framework emphasizing educational character of children’s play, as a specific form of learning. Notwithstanding occasional attempts within pedagogic theory to deny educational values of children’s play and to emphasize instruction as the only form of systematic learning, contemporary pedagogic views consider play an important part of school education. Learning through play at younger school age helps overcome the discontinuity between preschool and school education. Curriculum subject matter can be covered through carefully selected and prepared play activities within the existing system, providing the support, encouragement and guidance by the adults involved, including their proper knowledge of children’ age-related and psycho-physical characteristics. Play facilitates gradual change over from preschool to school developmental stage, free, spontaneous and creative expression and the development of children’s potential.

Effects of Holding an External Load on the Standing Balance of Older and Younger Adults With and Without Chronic Low Back Pain.

Science.gov (United States)

Shigaki, Leonardo; Vieira, Edgar Ramos; de Oliveira Gil, André Wilson; Araújo, Cynthia Gobbi Alves; Carmargo, Mariana Zingari; Sturion, Leandro Amaral; de Oliveira, Marcio Roǵerio; da Silva, Rubens A

2017-05-01

The purpose of this study was to assess the effect of holding an external load on the standing balance of younger and older adults with and without chronic low back pain (CLBP). Twenty participants with and 20 without CLBP participated in the study. Each group contained 10 younger (50% men) and 10 older adults (50% men). Participants were instructed to look straight ahead while standing on a force platform during two 120-second trials with and without holding an external load (10% of body mass). The center of pressure area, mean velocity, and mean frequency in the anteroposterior and mediolateral directions were measured. Older adults had worse standing balance than younger adults did (P external load significantly increased postural instability for both age groups and CLBP status, with mean effect size across center of pressure variables of d = 0.82 for older participants without CLBP and d = 2.65 for younger participants without CLBP. These effects for people with CLBP were d = 1.65 for subgroup of older and d = 1.60 for subgroup of younger participants. Holding an external load of 10% of body mass increased postural instability of both younger and older adults with and without CLBP. Copyright © 2017. Published by Elsevier Inc.

Assessment of anger expression using art therapy with younger school-age children with emotional and behavioral problems

OpenAIRE

Duobienė, Greta

2017-01-01

Greta D. Assessment of anger expression using art therapy with younger school-age children with emotional and behavioral problems, Master’s thesis / lecturer Dr. V. Grigaliūnienė, consultant Dr. A. Brazauskaitė; Lithuanian University of Health Sciences, Faculty of Nursing, , Kaunas Faculty of Vilnius Academy of Arts, Kaunas, 2017:107psl. The aim of this Master‘s thesis was to evaluate the changes in anger expression and control by using art therapy with younger school-age children that ha...

Tropical Indo-Pacific hydroclimate response to North Atlantic forcing during the last deglaciation as recorded by a speleothem from Sumatra, Indonesia

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Wurtzel, Jennifer B.; Abram, Nerilie J.; Lewis, Sophie C.; Bajo, Petra; Hellstrom, John C.; Troitzsch, Ulrike; Heslop, David

2018-06-01

Abrupt changes in Atlantic Meridional Overturning Circulation are known to have affected the strength of the Indian and Asian Monsoons during glacial and deglacial climate states. However, there is still much uncertainty around the hydroclimate response of the Indo-Pacific Warm Pool (IPWP) region to abrupt climate changes in the North Atlantic. Many studies suggest a mean southward shift in the intertropical convergence zone (ITCZ) in the IPWP region during phases of reduced Atlantic meridional overturning, however, existing proxies have seasonal biases and conflicting responses, making it difficult to determine the true extent of North Atlantic forcing in this climatically important region. Here we present a precisely-dated, high-resolution record of eastern Indian Ocean hydroclimate variability spanning the last 16 ky (thousand years) from δ18O measurements in an aragonite-calcite speleothem from central Sumatra. This represents the western-most speleothem record from the IPWP region. Precipitation arrives year-round at this site, with the majority sourced from the local tropical eastern Indian Ocean and two additional long-range seasonal sources associated with the boreal and austral summer monsoons. The Sumatran speleothem demonstrates a clear deglacial structure that includes 18O enrichment during the Younger Dryas and 18O depletion during the Bølling-Allerød, similar to the pattern seen in speleothems of the Asian and Indian monsoon realms. The speleothem δ18O changes at this site are best explained by changes in rainfall amount and changes in the contributions from different moisture pathways. Reduced rainfall in Sumatra during the Younger Dryas is most likely driven by reductions in moisture transport along the northern or southern monsoon transport pathways to Sumatra. Considered with other regional proxies, the record from Sumatra suggests the response of the IPWP to North Atlantic freshwater forcing is not solely driven by southward shifts of the

Vegetation and Climate Change during the Last Deglaciation in the Great Khingan Mountain, Northeastern China.

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Wu, Jing; Liu, Qiang; Wang, Luo; Chu, Guo-qiang; Liu, Jia-qi

2016-01-01

The Great Khingan Mountain range, Northeast China, is located on the northern limit of modern East Asian Summer Monsoon (EASM) and thus highly sensitive to the extension of the EASM from glacial to interglacial modes. Here, we present a high-resolution pollen record covering the last glacial maximum and the early Holocene from a closed crater Lake Moon to reconstruct vegetation history during the glacial-interglacial transition and thus register the evolution of the EASM during the last deglaciation. The vegetation history has gone through distinct changes from subalpine meadow in the last glacial maximum to dry steppe dominated by Artemisia from 20.3 to 17.4 ka BP, subalpine meadow dominated by Cyperaceae and Artemisia between 17.4 and 14.4 ka BP, and forest steppe dominated by Betula and Artemisia after 14.4 ka BP. The pollen-based temperature index demonstrates a gradual warming trend started at around 20.3 ka BP with interruptions of several brief events. Two cold conditions occurred around at 17.2-16.6 ka BP and 12.8-11.8 ka BP, temporally correlating to the Henrich 1 and the Younger Dryas events respectively, 1and abrupt warming events occurred around at 14.4 ka BP and 11.8 ka BP, probably relevant to the beginning of the Bølling-Allerød stages and the Holocene. The pollen-based moisture proxy shows distinct drought condition during the last glacial maximum (20.3-18.0 ka BP) and the Younger Dryas. The climate history based on pollen record of Lake Moon suggests that the regional temperature variability was coherent with the classical climate in the North Atlantic, implying the dominance of the high latitude processes on the EASM evolution from the Last Glacial Maximum (LGM) to early Holocene. The local humidity variability was influenced by the EASM limitedly before the Bølling-Allerød warming, which is mainly controlled by the summer rainfall due to the EASM front covering the Northeast China after that.

Vegetation and Climate Change during the Last Deglaciation in the Great Khingan Mountain, Northeastern China.

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Jing Wu

Full Text Available The Great Khingan Mountain range, Northeast China, is located on the northern limit of modern East Asian Summer Monsoon (EASM and thus highly sensitive to the extension of the EASM from glacial to interglacial modes. Here, we present a high-resolution pollen record covering the last glacial maximum and the early Holocene from a closed crater Lake Moon to reconstruct vegetation history during the glacial-interglacial transition and thus register the evolution of the EASM during the last deglaciation. The vegetation history has gone through distinct changes from subalpine meadow in the last glacial maximum to dry steppe dominated by Artemisia from 20.3 to 17.4 ka BP, subalpine meadow dominated by Cyperaceae and Artemisia between 17.4 and 14.4 ka BP, and forest steppe dominated by Betula and Artemisia after 14.4 ka BP. The pollen-based temperature index demonstrates a gradual warming trend started at around 20.3 ka BP with interruptions of several brief events. Two cold conditions occurred around at 17.2-16.6 ka BP and 12.8-11.8 ka BP, temporally correlating to the Henrich 1 and the Younger Dryas events respectively, 1and abrupt warming events occurred around at 14.4 ka BP and 11.8 ka BP, probably relevant to the beginning of the Bølling-Allerød stages and the Holocene. The pollen-based moisture proxy shows distinct drought condition during the last glacial maximum (20.3-18.0 ka BP and the Younger Dryas. The climate history based on pollen record of Lake Moon suggests that the regional temperature variability was coherent with the classical climate in the North Atlantic, implying the dominance of the high latitude processes on the EASM evolution from the Last Glacial Maximum (LGM to early Holocene. The local humidity variability was influenced by the EASM limitedly before the Bølling-Allerød warming, which is mainly controlled by the summer rainfall due to the EASM front covering the Northeast China after that.

Deglacial and Holocene sea-ice variability north of Iceland and response to ocean circulation changes

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Xiao, Xiaotong; Zhao, Meixun; Knudsen, Karen Luise; Sha, Longbin; Eiríksson, Jón; Gudmundsdóttir, Esther; Jiang, Hui; Guo, Zhigang

2017-08-01

Sea-ice conditions on the North Icelandic shelf constitute a key component for the study of the climatic gradients between the Arctic and the North Atlantic Oceans at the Polar Front between the cold East Icelandic Current delivering Polar surface water and the relatively warm Irminger Current derived from the North Atlantic Current. The variability of sea ice contributes to heat reduction (albedo) and gas exchange between the ocean and the atmosphere, and further affects the deep-water formation. However, lack of long-term and high-resolution sea-ice records in the region hinders the understanding of palaeoceanographic change mechanisms during the last glacial-interglacial cycle. Here, we present a sea-ice record back to 15 ka (cal. ka BP) based on the sea-ice biomarker IP25, phytoplankton biomarker brassicasterol and terrestrial biomarker long-chain n-alkanols in piston core MD99-2272 from the North Icelandic shelf. During the Bølling/Allerød (14.7-12.9 ka), the North Icelandic shelf was characterized by extensive spring sea-ice cover linked to reduced flow of warm Atlantic Water and dominant Polar water influence, as well as strong meltwater input in the area. This pattern showed an anti-phase relationship with the ice-free/less ice conditions in marginal areas of the eastern Nordic Seas, where the Atlantic Water inflow was strong, and contributed to an enhanced deep-water formation. Prolonged sea-ice cover with occasional occurrence of seasonal sea ice prevailed during the Younger Dryas (12.9-11.7 ka) interrupted by a brief interval of enhanced Irminger Current and deposition of the Vedde Ash, as opposed to abruptly increased sea-ice conditions in the eastern Nordic Seas. The seasonal sea ice decreased gradually from the Younger Dryas to the onset of the Holocene corresponding to increasing insolation. Ice-free conditions and sea surface warming were observed for the Early Holocene, followed by expansion of sea ice during the Mid-Holocene.

Deglacial sea level history of the East Siberian Sea and Chukchi Sea margins

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Cronin, Thomas M.; O'Regan, Matt; Pearce, Christof; Gemery, Laura; Toomey, Michael; Semiletov, Igor; Jakobsson, Martin

2017-09-01

Deglacial (12.8-10.7 ka) sea level history on the East Siberian continental shelf and upper continental slope was reconstructed using new geophysical records and sediment cores taken during Leg 2 of the 2014 SWERUS-C3 expedition. The focus of this study is two cores from Herald Canyon, piston core SWERUS-L2-4-PC1 (4-PC1) and multicore SWERUS-L2-4-MC1 (4-MC1), and a gravity core from an East Siberian Sea transect, SWERUS-L2-20-GC1 (20-GC1). Cores 4-PC1 and 20-GC were taken at 120 and 115 m of modern water depth, respectively, only a few meters above the global last glacial maximum (LGM; ˜ 24 kiloannum or ka) minimum sea level of ˜ 125-130 meters below sea level (m b.s.l.). Using calibrated radiocarbon ages mainly on molluscs for chronology and the ecology of benthic foraminifera and ostracode species to estimate paleodepths, the data reveal a dominance of river-proximal species during the early part of the Younger Dryas event (YD, Greenland Stadial GS-1) followed by a rise in river-intermediate species in the late Younger Dryas or the early Holocene (Preboreal) period. A rapid relative sea level rise beginning at roughly 11.4 to 10.8 ka ( ˜ 400 cm of core depth) is indicated by a sharp faunal change and unconformity or condensed zone of sedimentation. Regional sea level at this time was about 108 m b.s.l. at the 4-PC1 site and 102 m b.s.l. at 20-GC1. Regional sea level near the end of the YD was up to 42-47 m lower than predicted by geophysical models corrected for glacio-isostatic adjustment. This discrepancy could be explained by delayed isostatic adjustment caused by a greater volume and/or geographical extent of glacial-age land ice and/or ice shelves in the western Arctic Ocean and adjacent Siberian land areas.

Early Holocene humidity patterns in the Iberian Peninsula reconstructed from lake, pollen and speleothem records

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Morellón, Mario; Aranbarri, Josu; Moreno, Ana; González-Sampériz, Penélope; Valero-Garcés, Blas L.

2018-02-01

Comparison of selected, well-dated, lacustrine, speleothem and terrestrial pollen records spanning the Holocene onset and the Early Holocene (ca. 11.7-8 cal kyrs BP) in the Iberian Peninsula shows large hydrological fluctuations and landscape changes with a complex regional pattern in timing and intensity. Marine pollen records from Alboran, the Mediterranean and off shore Atlantic sites show a step-wise increase in moisture and forest during this transition. However, available continental records point to two main patterns of spatial and temporal hydrological variability: i) Atlantic-influenced sites located at the northwestern areas (Enol, Sanabria, Lucenza, PRD-4), characterized by a gradual increase in humidity from the end of the Younger Dryas to the Mid Holocene, similarly to most North Atlantic records; and ii) continental and Mediterranean-influenced sites (Laguna Grande, Villarquemado, Fuentillejo, Padul, Estanya, Banyoles, Salines), with prolonged arid conditions of variable temporal extension after the Younger Dryas, followed by an abrupt increase in moisture at 10-9 cal kyrs BP. Different local climate conditions influenced by topography or the variable sensitivity (gradual versus threshold values) of the proxies analyzed in each case are evaluated. Vegetation composition (conifers versus mesothermophilous taxa) and resilience would explain a subdued response of vegetation in central continental areas while in Mediterranean sites, insufficient summer moisture availability could not maintain high lake levels and promote mesophyte forest, in contrast to Atlantic-influenced areas. Comparison with available climate models, Greenland ice cores, North Atlantic marine sequences and continental records from Central and Northern Europe and the whole Mediterranean region underlines the distinctive character of the hydrological changes occurred in inner Iberia throughout the Early Holocene. The persistent arid conditions might be explained by the intensification

Digital clock drawing: Differentiating ‘thinking’ versus ‘doing’ in younger and older adults with depression

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Cohen, Jamie; Penney, Dana L.; Davis, Randall; Libon, David J.; Swenson, Rodney A.; Ajilore, Olusola; Kumar, Anand; Lamar, Melissa

2015-01-01

Objective Psychomotor slowing has been documented in depression. The digital Clock Drawing Test (dCDT) provides: i) a novel technique to assess both cognitive and motor aspects of psychomotor speed within the same task and ii) the potential to uncover subtleties of behavior not previously detected with non-digitized modes of data collection. Method Using digitized pen technology in 106 participants grouped by Age (younger/older) and Affect (euthymic/unmedicated depressed), we recorded cognitive and motor output by capturing how the clock is drawn rather than focusing on the final product. We divided time to completion (TTC) for Command and Copy conditions of the dCDT into metrics of percent of drawing (%Ink) versus non-drawing (%Think) time. We also obtained composite z-scores of cognition, including attention/ information processing (AIP), to explore associations of %Ink and %Think times to cognitive and motor performance. Results Despite equivalent TTC, %Ink and %Think Command times (Copy n.s.) were significant (AgeXAffect interaction:p=.03)—younger depressed spent a smaller proportion of time drawing relative to thinking compared to the older depressed group. Command %Think time negatively correlated with AIP in the older depressed group (r=−.46;p=.02). Copy %Think time negatively correlated with AIP in the younger depressed (r=−.47;p=.03) and older euthymic groups (r=−.51;p=.01). Conclusion The dCDT differentiated aspects of psychomotor slowing in depression regardless of age, while dCDT/cognitive associates for younger adults with depression mimicked patterns of older euthymics. PMID:25222513

Etiology of Diarrhea in Children Younger Than 5 Years Attending the Bengo General Hospital in Angola.

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Gasparinho, Carolina; Mirante, Maria Clara; Centeno-Lima, Sónia; Istrate, Claudia; Mayer, António Carlos; Tavira, Luis; Nery, Susana Vaz; Brito, Miguel

2016-02-01

Diarrheal disease is among the leading causes of death in children younger than 5 years, especially in developing countries. The aim of this study was to investigate the most frequent etiological agents of diarrhea and its associated factors in children younger than 5 years attending the Bengo General Hospital in Angola. From September 2012 through December 2013, stool samples were collected from 344 children presenting with diarrhea to investigate the presence of viral, bacterial and parasitic agents. Relevant sociodemographic and clinical data were obtained from parents and caregivers. An enteric pathogen was detected in 66.6% of stool samples: Cryptosporidium spp. (30.0%), rotavirus (25.1%), Giardia lamblia (21.6%), diarrheagenic Escherichia coli (6.3%), Ascaris lumbricoides (4.1%), adenovirus (3.8%), Strongyloides stercoralis (3.5%), astrovirus (2.6%), Hymenolepis nana (1.7%), Entamoeba histolytica/dispar (0.9%), Taenia spp. (0.6%), Trichuris trichiura (0.3%) and Entamoeba histolytica (0.3%). Children younger than 12 months were more frequently infected with Cryptosporidium spp. compared with older children (age: 12-59 months), independently of sex, season, lethargy and wasting [odds ratio (OR): 3.5, 95% confidence interval (95% CI): 2.0-6.2]. Age (OR: 5.0, 95% CI: 2.6-9.3), vomiting (OR: 2.7, 95% CI: 1.5-4.8) and type of admission (inpatients, OR: 0.5, 95% CI: 0.3-0.9) were significantly associated with rotavirus infection. This study demonstrates high rates of infection with an enteric pathogen, particularly in children younger than 12 months, emphasizing the need to address diarrheal disease in this age group.

Self-confidence in financial analysis: a study of younger and older male professional analysts.

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Webster, R L; Ellis, T S

2001-06-01

Measures of reported self-confidence in performing financial analysis by 59 professional male analysts, 31 born between 1946 and 1964 and 28 born between 1965 and 1976, were investigated and reported. Self-confidence in one's ability is important in the securities industry because it affects recommendations and decisions to buy, sell, and hold securities. The respondents analyzed a set of multiyear corporate financial statements and reported their self-confidence in six separate financial areas. Data from the 59 male financial analysts were tallied and analyzed using both univariate and multivariate statistical tests. Rated self-confidence was not significantly different for the younger and the older men. These results are not consistent with a similar prior study of female analysts in which younger women showed significantly higher self-confidence than older women.

Feelings towards Older vs. Younger Adults: Results from the European Social Survey

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Ayalon, Liat

2013-01-01

The study evaluated the association of modernization (at the macro/societal-level) and modernity (at the micro/individual-level) with feelings towards older vs. younger adults. Analysis was based on the fourth wave of the European Social Survey, which includes a rotated module on ageism. The sample consisted of 28 countries and a total of 54,988…

Emotional expressivity in older and younger adults' descriptions of personal memories.

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Schryer, Emily; Ross, Michael; St Jacques, Peggy; Levine, Brian; Fernandes, Myra

2012-01-01

BACKGROUND/STUDY CONTEXT: According to the socioemotional selectivity theory (SST; Mather & Carstensen, 2003, Psychological Sciences, 14, 409-415), aging is associated with greater motivation to regulate emotions. The authors propose that the language people use to describe personal memories provides an index of age differences in emotional self-regulation. In the present article, the authors reanalyzed three previously published studies in which older (aged 60-88) and younger (aged 17-33) participants described emotional and neutral memories from their recent and distant pasts. The authors analyzed the language of the memories using Pennebaker, Booth, and Francis's (2007) Linguistic Inquiry Word Count program (Austin, TX: LIWC Inc.), which calculates the percentage of positive and negative emotion words. In Studies 1 and 2, older adults used more positive emotion words than did younger adults to describe their autobiographical memories from the recent past, particularly when these were of a neutral valence. In Study 3, older adults used more positive emotion words when describing more recent memories (from the past 5 years) but not when describing distant childhood or adolescent memories. The authors suggest that these age differences in emotional expressivity support SST, and represent an as-yet unreported age difference that may stem from differences in motivation to regulate emotion.

Types of phone usage: Age differences between younger and older persons

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Simona-Nicoleta Vulpe

2017-12-01

Full Text Available I Even if more and more people use mobile phones, the gap between younger and older age groups persists and its importance is timely and widened given the present ageing and digital inequality phenomena. How wide is the difference on types of phone usage between different age groups? For answering this research question, we employ binary logistic regressions on several types of phone usage keeping into account age and controlling for region, education, income and whether respondents use a feature phone or a smartphone. The analysed data come from the Spring Change Assessment Survey 2010 provided by the Pew Research Center and it is representative for the United States of America. Our results show that, net of the all the variables included in the model, older persons are less likely than younger persons to use such phone functions, but the strength of association is low. Education and income are relevant for these functions. Using a smartphone in comparison with using a feature phone is important in all the situations included, as well as income. Considering models only for older persons, over 65 years of age, college and income are less relevant. Using a smartphone is more likely than using a feature phone to encourage all types of phone usage, independently of age.

THE WILLINGNESS OF TEACHERS AS A CONDITION FOR PRODUCTIVE INNOVATIVE EDUCATIONAL ACTIVITIES FOR YOUNGER STUDENTS

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Maria Ivanchuk

2017-03-01

Full Text Available The article is analyzed approaches and defined the essence of readiness of teachers to innovative educational activities in the primary education. The meanings of “innovative educational activity”, “the willingness of students to innovative educational activities” are clarified. The essence and role of motivational, cognitive, creative and incentive-praxeology components of this readiness is analysed. Identified, theoretically grounded and experimentally tested pedagogical conditions of formation of readiness of students to innovative educational activities with younger students in the process of pedagogical practice. Developed a program of optimization of innovative educational activities with younger students in the process of pedagogical practice, which covers a system of structured types. The tests showed the efficiency performance of different types of individual and group work with students (experience with innovative educational technologies and their implementation; discussion of issues of innovation in education; implementation of dialogue forms of communication between the actors of the educational process, the formation of aspirations, the desire to highlight the goals, objectives, build a plan of its own search of innovative work; develop skills to make the transition from algorithmisation, stereotypical techniques to subjectively new etc.. Methodical recommendations are offered for improving the preparation of students for innovative educational activities with the younger students.

Temporo-spatial gait parameters during street crossing conditions: a comparison between younger and older adults.

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Vieira, Edgar R; Lim, Hyun-Hwa; Brunt, Denis; Hallal, Camilla Z; Kinsey, Laura; Errington, Lisa; Gonçalves, Mauro

2015-02-01

Most traffic accidents involving pedestrians happen during street crossing. Safe street crossing by older adults requires complex planning and imposes high cognitive demands. Understanding how street crossing situations affect younger and older adults' gait is important to create evidence-based policies, education and training. The objective of this study was to develop and test a method to evaluate temporo-spatial gait parameters of younger and older adults during simulated street crossing situations. Twenty-two younger (25±2 years old) and 22 older adults (73±6 years old) who lived independently in the community completed 3 walking trials at preferred gait speed and during simulated street crossing with regular and with reduced time. There were significant differences between groups (pstreet crossing walking speed was higher than their preferred speed (pstreet crossing resulted in significant and progressive gait changes. The methods developed and tested can be used to (1) evaluate if people are at risk of falls and accidents during street crossing situations, (2) to compare among different groups, and (3) to help establish appropriate times for older pedestrians to cross streets safely. The current time to cross streets is too short even for healthy older adults. Copyright © 2014 Elsevier B.V. All rights reserved.

[Otitis media with effusion in children younger than 1 year].

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Di Francesco, Renata Cantisani; Barros, Vivian Boschesi; Ramos, Rafael

2016-06-01

To determine the prevalence of otitis media with effusion in children younger than 1 year and its association with the season of the year, artificial feeding, environmental and perinatal factors. Retrospective study of 184 randomly included medical records from a total of 982 healthy infants evaluated for hearing screening tests. Diagnosis of otitis media with effusion was based on otoscopy (amber-gold color, fluid level, handle of malleus position), type B tympanometric curves and absence of otoacoustic emissions. Incomplete medical records or those describing acute otitis media, upper respiratory tract infections on the assessment day or in the last 3 months, neuropathies and craniofacial anomalies were excluded. Data such as gestational age, birth weight, Apgar score, type of feeding and day care attendance were compared between children with and without otitis media with effusion through likelihood tests and multivariate analysis. 25.3% of 184 infants had otitis media with bilateral effusion; 9.2% had unilateral. In infants with otitis media, the following were observed: chronological age of 9.6±1.7 months; gestational age >38 weeks in 43.4% and birth weight >2,500g in 48.4%. Otitis media with effusion was associated with winter/fall, artificial feeding, Apgar score otitis media with effusion. Otitis media with effusion was found in about one third of children younger than 1 year and was mainly associated with artificial feeding. Copyright © 2015 Sociedade de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

[Rheumatic cardiopathy in children younger than 6 years of age].

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Vázquez-Antona, C; Calderón-Colmenero, J; Attié, F; Zabal, C; Buendía-Hernández, A; Díaz-Medina, L H; Bialkowski, J; García Arenal, F

1991-01-01

Most of the published papers on Rheumatic Fever (RF) have not included the younger population. We selected 211 cases of children with RF younger than 6 years of age from 9,471 clinical files from 1944 to 1982. These were followed retrospectively to identify the presence of rheumatic activity, subsequent attacks and penicillin profilaxis. From de 211 cases, 209 had carditis; 57% of them were girls and 43% boys. There were no previous infections of the upper respiratory tract in 36% of the patients. The number of cases with RF increased abruptly after 3 years of age and continued increasing until 5 years of age when 70.5% of the population had there first clinically recognized attack. Lesions were present in the mitral valve in 80% of the cases, in the aortic valve in 12%, in the tricuspid in 5% and in the pulmonary valve in 3%. The death rate during the first attack was 20% being refractory heart failure the main cause of death. Thirteen cases suffered rheumatic pneumonia, 9 of whom died (69.2%). 1) The incidence of acute rheumatic fever in children under 6 years of age has decreased with time. 2) The death rate as well as the valvular damage decreased with the parents cooperation with the treatment. 3) The changes in the clinical picture and the severity of valve sequelea may be due to penicillin profilaxis and the better understanding of the disease.

A failure of serendipity: the Square Kilometre Array will struggle to eavesdrop on human-like extraterrestrial intelligence

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Forgan, D. H.; Nichol, R. C.

2011-04-01

The Square Kilometre Array (SKA) will operate in frequency ranges often used by military radar and other communications technology. It has been shown that if extraterrestrial intelligences (ETIs) communicate using similar technology, then the SKA should be able to detect such transmissions up to distances of ~100 pc (~300 light years) from Earth. However, Mankind has greatly improved its communications technology over the last century, dramatically reducing signal leakage and making the Earth ‘radio quiet’. If ETIs follow the same pattern as the human race, will we be able to detect their signal leakage before they become radio quiet? We investigate this question using Monte Carlo realization techniques to simulate the growth and evolution of intelligent life in the Galaxy. We show that if civilizations are ‘human’ in nature (i.e. they are only ‘radio loud’ for ~100 years, and can only detect each other with an SKA-like instrument out to 100 pc, within a maximum communication time of 100 years), then the probability for such civilizations accidentally detecting each other is low (~10-7), much lower than if other, dedicated communication techniques are permissible (e.g. optical SETI or neutrino communication).

Fluid-induced organic synthesis in the solar nebula recorded in extraterrestrial dust from meteorites.

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Vollmer, Christian; Kepaptsoglou, Demie; Leitner, Jan; Busemann, Henner; Spring, Nicole H; Ramasse, Quentin M; Hoppe, Peter; Nittler, Larry R

2014-10-28

Isotopically anomalous carbonaceous grains in extraterrestrial samples represent the most pristine organics that were delivered to the early Earth. Here we report on gentle aberration-corrected scanning transmission electron microscopy investigations of eight (15)N-rich or D-rich organic grains within two carbonaceous Renazzo-type (CR) chondrites and two interplanetary dust particles (IDPs) originating from comets. Organic matter in the IDP samples is less aromatic than that in the CR chondrites, and its functional group chemistry is mainly characterized by C-O bonding and aliphatic C. Organic grains in CR chondrites are associated with carbonates and elemental Ca, which originate either from aqueous fluids or possibly an indigenous organic source. One distinct grain from the CR chondrite NWA 852 exhibits a rim structure only visible in chemical maps. The outer part is nanoglobular in shape, highly aromatic, and enriched in anomalous nitrogen. Functional group chemistry of the inner part is similar to spectra from IDP organic grains and less aromatic with nitrogen below the detection limit. The boundary between these two areas is very sharp. The direct association of both IDP-like organic matter with dominant C-O bonding environments and nanoglobular organics with dominant aromatic and C-N functionality within one unique grain provides for the first time to our knowledge strong evidence for organic synthesis in the early solar system activated by an anomalous nitrogen-containing parent body fluid.

Amphetamine modulates brain signal variability and working memory in younger and older adults.

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Garrett, Douglas D; Nagel, Irene E; Preuschhof, Claudia; Burzynska, Agnieszka Z; Marchner, Janina; Wiegert, Steffen; Jungehülsing, Gerhard J; Nyberg, Lars; Villringer, Arno; Li, Shu-Chen; Heekeren, Hauke R; Bäckman, Lars; Lindenberger, Ulman

2015-06-16

Better-performing younger adults typically express greater brain signal variability relative to older, poorer performers. Mechanisms for age and performance-graded differences in brain dynamics have, however, not yet been uncovered. Given the age-related decline of the dopamine (DA) system in normal cognitive aging, DA neuromodulation is one plausible mechanism. Hence, agents that boost systemic DA [such as d-amphetamine (AMPH)] may help to restore deficient signal variability levels. Furthermore, despite the standard practice of counterbalancing drug session order (AMPH first vs. placebo first), it remains understudied how AMPH may interact with practice effects, possibly influencing whether DA up-regulation is functional. We examined the effects of AMPH on functional-MRI-based blood oxygen level-dependent (BOLD) signal variability (SD(BOLD)) in younger and older adults during a working memory task (letter n-back). Older adults expressed lower brain signal variability at placebo, but met or exceeded young adult SD(BOLD) levels in the presence of AMPH. Drug session order greatly moderated change-change relations between AMPH-driven SD(BOLD) and reaction time means (RT(mean)) and SDs (RT(SD)). Older adults who received AMPH in the first session tended to improve in RT(mean) and RT(SD) when SD(BOLD) was boosted on AMPH, whereas younger and older adults who received AMPH in the second session showed either a performance improvement when SD(BOLD) decreased (for RT(mean)) or no effect at all (for RT(SD)). The present findings support the hypothesis that age differences in brain signal variability reflect aging-induced changes in dopaminergic neuromodulation. The observed interactions among AMPH, age, and session order highlight the state- and practice-dependent neurochemical basis of human brain dynamics.

Tomosynthesis Impact on Breast Cancer Screening in Patients Younger Than 50 Years Old.

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Rose, Stephen L; Shisler, Julie L

2018-04-09

The question of benefits versus harms of breast cancer screening for women younger than 50 years old has been the subject of debate. We investigate if the addition of tomosynthesis to mammography improves screening performance outcomes for women in this age group. Screening performance for 59,921 patients (41,542 digital mammography and 18,379 tomosynthesis) younger than 50 years old was collected from a community-based screening network from January 1, 2015, to December 31, 2015. Patients were offered tomosynthesis if it was available. Parameters including recall, biopsy, and cancer detection rates were compared. Mixed effects regression analysis was used to estimate rates with screening modality, age, and density as fixed effects and screening site as a random effect. Rates for patients with dense breast tissue were also evaluated. Model adjusted rates per 1000 screenings with digital mammography were compared with digital mammography plus tomosynthesis, respectively: recall rate decreased from 117 to 108 (difference, -8.3; p = 0.003); biopsy rate increased from 13.5 to 16.6 (difference, 3.1; p = 0.003); and cancer detection rate increased from 1.9 to 2.6 (difference, 0.8; p = 0.060). Model adjusted rates for patients with dense breast tissue were: recall rate decreased from 135 to 132 (difference, -3.2; p = 0.44); biopsy rate increased from 16.0 to 20.5 (difference, 4.5; p = 0.004); and cancer detection rate increased from 2.1 to 3.5 (difference, 1.3; p = 0.03). Tomosynthesis in a community setting resulted in decreased recall rates for patients younger than 50 years old. For the subgroup of women with dense breast tissue, cancer detection rates also increased.

Whole-Person Impairment in Younger Retired NFL Players: The Orthopaedic Toll of a Professional Football Career.

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Domb, Benjamin G; Carter, Chris; Finch, Nathan A; Hammarstedt, Jon E; Dunne, Kevin F; Stake, Christine E

2014-05-01

Professional American football is a physically demanding, high-impact sport with an elevated risk of injury. Orthopaedic injuries may impose acute, short-term or cumulative consequences throughout a player's lifetime. Several studies have addressed health and psychosocial concerns of an older, retired population of players in the National Football League (NFL); however, minimal research has examined the orthopaedic toll on younger, retired players. This study reports total whole-person impairment (WPI) percentages in a cohort of younger, retired NFL players who presented for disability evaluations based on the use of standardized American Medical Association (AMA) impairment guidelines. Case series; Level of evidence, 4. During the study period of February 2011 to August 2013, 65 younger retired NFL players presented for impairment evaluations. The mean time between retirement and impairment evaluation was 3.1 years (range, 0.3-16.4 years). A complete history and physical examination was performed on all symptomatic joints. A retrospective chart review was conducted on 100% of presenting players to assess orthopaedic burden. Body-part impairment (BPI) percentage for each affected joint was generated. The impairment data for each extremity were then combined with spine impairment data to create WPI percentage. Player demographics, including age, position, and playing time, were also recorded. The average WPI percentage was 37% (range, 19%-53%). Players participating in >30 games (n = 54) had a higher mean WPI percentage (38%) than those playing in 5 seasons (n = 46) were 2.4 times more likely to have a WPI of at least 37% (P = .007). The most common joints players reported as symptomatic were lumbar (n = 63; 97%) and cervical spine (n = 58; 89%). The mean age at evaluation was 33.5 years (range, 27-42 years), and the mean number of seasons played was 7.5 (range, 3-14 seasons). The mean number of games played was 98.4 (range, 2-236 games). This study demonstrated

Lifestyle, cardiovascular drugs and risk factors in younger and elder adults: The PEP family heart study

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Peter Schwandt

2010-01-01

Full Text Available Objectives: This study aimed to compare cardiovascular disease (CVD risk factors, lifestyle habits and pharmacological treatment in two groups of elder adults with 20 years difference in their mean age. Methods: This study comprised 590 women including two groups with mean age of 42.4±5.5 vs. 66.5±4.0 years, and 486 men of two groups with mean age of 44.1±5.6 vs. 63.9±7.0 years. Data on physical examination, fasting blood analyses, 7-day dietary re-cords, physical activity, smoking and actual medication use were recorded. Results: Compared with younger individuals, seniors had a more adverse risk factor profile in terms of abdominal obesity, over-weight, hyperglycemia, hypertension, dyslipoproteinemia without differences in HDL-C. But this is not reflected by lifestyle behav-ior. Less than 2% of the elderly and 17% of the younger adults were current smoker. Furthermore, the pattern of physical activ-ity was different in terms of more continuous sports in seniors contrasting with extremes between no sports and more than twice a week in the younger group. Seniors consumed significantly less carbohydrates including more monosaccharide and less polysaccharides, more alcohol and water. The intake of fat and protein was higher in elder women than in all other groups. One third of seniors took antihypertensive medications and 12% used lipid modifying drugs. Conclusions: Different levels of prevention against CVDs and their risk factors shall be considered for various age groups of population. The findings of this study emphasize on the necessity of preventive measures against smoking and physical inactivity in younger adults and dietary habits in seniors.

The efficacy of problem solving therapy to reduce post stroke emotional distress in younger (18-65) stroke survivors.

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Chalmers, Charlotte; Leathem, Janet; Bennett, Simon; McNaughton, Harry; Mahawish, Karim

2017-11-26

To investigate the efficacy of problem solving therapy for reducing the emotional distress experienced by younger stroke survivors. A non-randomized waitlist controlled design was used to compare outcome measures for the treatment group and a waitlist control group at baseline and post-waitlist/post-therapy. After the waitlist group received problem solving therapy an analysis was completed on the pooled outcome measures at baseline, post-treatment, and three-month follow-up. Changes on outcome measures between baseline and post-treatment (n = 13) were not significantly different between the two groups, treatment (n = 13), and the waitlist control group (n = 16) (between-subject design). The pooled data (n = 28) indicated that receiving problem solving therapy significantly reduced participants levels of depression and anxiety and increased quality of life levels from baseline to follow up (within-subject design), however, methodological limitations, such as the lack of a control group reduce the validity of this finding. The between-subject results suggest that there was no significant difference between those that received problem solving therapy and a waitlist control group between baseline and post-waitlist/post-therapy. The within-subject design suggests that problem solving therapy may be beneficial for younger stroke survivors when they are given some time to learn and implement the skills into their day to day life. However, additional research with a control group is required to investigate this further. This study provides limited evidence for the provision of support groups for younger stroke survivors post stroke, however, it remains unclear about what type of support this should be. Implications for Rehabilitation Problem solving therapy is no more effective for reducing post stroke distress than a wait-list control group. Problem solving therapy may be perceived as helpful and enjoyable by younger stroke survivors. Younger stroke

The Influence of Emotional Material on Encoding and Retrieving Intentions: An ERP Study in Younger and Older Adults

Science.gov (United States)

Hering, Alexandra; Kliegel, Matthias; Bisiacchi, Patrizia S.; Cona, Giorgia

2018-01-01

Prospective memory is a cognitive process that comprises the encoding and maintenance of an intention until the appropriate moment of its retrieval. It is of highly relevance for an independent everyday life, especially in older adults; however, there is ample evidence that prospective memory declines with increasing age. Because most studies have used neutral stimuli, it is still an open question how emotional factors influence age-related differences in prospective remembering. The aim of the study was to investigate the influence of emotional material on prospective memory encoding, monitoring, maintaining, and retrieval in younger and older adults using behavioral and electrophysiological measures. We tested 24 younger adults (M = 26.4 years) and 20 older adults (M = 68.1 years) using a picture one-back task as ongoing activity with an embedded prospective memory instruction. The experimental task consisted of three sessions. In each session, participants had to encode series of images that represented the prospective memory cues for the consecutive block. The images were either of pleasant, unpleasant, or neutral valence. The pictures used in the ongoing task were likewise of pleasant, unpleasant, or neutral valence. Event-related potentials (ERPs) were recorded to assess the neural correlates of intention encoding, maintenance, and self-initiated retrieval. We did not find age differences between younger and older adults on the behavioral level. However, the ERP results revealed an interesting pattern that suggested for both age groups elevated attentional processing of emotional cues during encoding indicated by an elevated LPP for the emotional cues. Additionally, younger adults showed increased activity for unpleasant cues. During the maintenance phase, both age groups engaged in strategic monitoring especially for pleasant cues, which led to enhanced sustained positivity. During retrieval, older adults showed increased activity of ERP components related

The Influence of Emotional Material on Encoding and Retrieving Intentions: An ERP Study in Younger and Older Adults

Directory of Open Access Journals (Sweden)

Alexandra Hering

2018-02-01

Full Text Available Prospective memory is a cognitive process that comprises the encoding and maintenance of an intention until the appropriate moment of its retrieval. It is of highly relevance for an independent everyday life, especially in older adults; however, there is ample evidence that prospective memory declines with increasing age. Because most studies have used neutral stimuli, it is still an open question how emotional factors influence age-related differences in prospective remembering. The aim of the study was to investigate the influence of emotional material on prospective memory encoding, monitoring, maintaining, and retrieval in younger and older adults using behavioral and electrophysiological measures. We tested 24 younger adults (M = 26.4 years and 20 older adults (M = 68.1 years using a picture one-back task as ongoing activity with an embedded prospective memory instruction. The experimental task consisted of three sessions. In each session, participants had to encode series of images that represented the prospective memory cues for the consecutive block. The images were either of pleasant, unpleasant, or neutral valence. The pictures used in the ongoing task were likewise of pleasant, unpleasant, or neutral valence. Event-related potentials (ERPs were recorded to assess the neural correlates of intention encoding, maintenance, and self-initiated retrieval. We did not find age differences between younger and older adults on the behavioral level. However, the ERP results revealed an interesting pattern that suggested for both age groups elevated attentional processing of emotional cues during encoding indicated by an elevated LPP for the emotional cues. Additionally, younger adults showed increased activity for unpleasant cues. During the maintenance phase, both age groups engaged in strategic monitoring especially for pleasant cues, which led to enhanced sustained positivity. During retrieval, older adults showed increased activity of ERP

Evaluating suggestibility to additive and contradictory misinformation following explicit error detection in younger and older adults.

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Huff, Mark J; Umanath, Sharda

2018-06-01

In 2 experiments, we assessed age-related suggestibility to additive and contradictory misinformation (i.e., remembering of false details from an external source). After reading a fictional story, participants answered questions containing misleading details that were either additive (misleading details that supplemented an original event) or contradictory (errors that changed original details). On a final test, suggestibility was greater for additive than contradictory misinformation, and older adults endorsed fewer false contradictory details than younger adults. To mitigate suggestibility in Experiment 2, participants were warned about potential errors, instructed to detect errors, or instructed to detect errors after exposure to examples of additive and contradictory details. Again, suggestibility to additive misinformation was greater than contradictory, and older adults endorsed less contradictory misinformation. Only after detection instructions with misinformation examples were younger adults able to reduce contradictory misinformation effects and reduced these effects to the level of older adults. Additive misinformation however, was immune to all warning and detection instructions. Thus, older adults were less susceptible to contradictory misinformation errors, and younger adults could match this misinformation rate when warning/detection instructions were strong. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Ultra-long pharmacokinetic properties of insulin degludec are comparable in elderly subjects and younger adults with type 1 diabetes mellitus.

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Korsatko, S; Deller, S; Mader, J K; Glettler, K; Koehler, G; Treiber, G; Urschitz, M; Wolf, M; Hastrup, H; Søndergaard, F; Haahr, H; Pieber, T R

2014-01-01

Management of diabetes in elderly subjects is complex and careful management of glucose levels is of particular importance in this population because of an increased risk of diabetes-related complications and hypoglycaemia. The aim of this study was to evaluate the pharmacokinetic and pharmacodynamic properties of insulin degludec (IDeg), a basal insulin with an ultra-long duration of action, in elderly subjects with type 1 diabetes compared with younger adults. This trial was a randomised, double-blind, two-period, crossover trial conducted in a single centre and included both inpatient and outpatient periods. Subjects were men and women aged 18-35 years inclusive (younger adult group) or ≥65 years (elderly group) with type 1 diabetes who received IDeg (0.4 U/kg) via subcutaneous injection in the thigh once-daily for six days. Following 6-day dosing, a 26-hour euglycaemic glucose clamp procedure was conducted to evaluate the steady-state pharmacodynamic effects of IDeg. Blood samples were taken for pharmacokinetic analysis up to 120 h post-dose. Pharmacokinetic endpoints included the total exposure of IDeg, ie the area under the IDeg serum concentration curve during one dosing interval at steady state (AUC(IDeg,τ,SS)) (τ = 0-24 h, equal to one dosing interval) and the maximum IDeg serum concentration at steady state (C(max,IDeg,SS)). Pharmacodynamic endpoints included the total glucose-lowering effect of IDeg, ie the area under the glucose infusion rate (GIR) curve at steady state (AUC(GIR,τ,SS)), and the maximum GIR at steady state (GIR(max,IDeg,SS)). Total exposure (AUC(IDeg,τ,SS)) and maximum concentration (C(max,IDeg,SS)) of IDeg were comparable between elderly subjects and younger adults. Estimated mean age group ratios (elderly/younger adult) for AUC(IDeg,τ,SS) and C(max,IDeg,SS) and corresponding two-sided 95 % confidence intervals (CIs) were 1.04 (95 % CI 0.73-1.47) and 1.02 (95 % CI 0.74-1.39), respectively. Mean AUC(IDeg,0-12h

A qualitative metasynthesis exploring the impact of prostate cancer and its management on younger, unpartnered and gay men.

Science.gov (United States)

Matheson, L; Watson, E K; Nayoan, J; Wagland, R; Glaser, A; Gavin, A; Wright, P; Rivas, C

2017-11-01

Prostate cancer (PCa) can negatively impact on men's sexual, urinary and emotional functioning, affecting quality of life. Most men with PCa are older (≥65 years), married and heterosexual and little is known about the impact on men who are younger, unpartnered or gay. We aimed to synthesise existing qualitative research on these three groups of men. A systematic metasynthesis was undertaken that included data on the unique impacts of PCa on younger (identity-illustrating the multiple threats to men's work, sexual and social identities; shifting into different communities of practice-such as the shift from being part of a sexually active community to celibacy. These findings suggest that PCa can have a particular impact on the quality of life of younger, unpartnered and gay men. This has implications for the provision of tailored support and information to these potentially marginalised groups. © 2017 John Wiley & Sons Ltd.

Stereotypes of older employees compared to younger employees in Slovenian companies

OpenAIRE

Rožman, Maja; Treven, Sonja; Čančer, Vesna

2016-01-01

Human resource management has an important impact on age diversity in companies. Age diversity in the workplace is growing and older employees are staying longer in the workforce, therefore it is important that employers can create a positive environment for age diverse employees. This paper introduces the difference in stereotypes in the workplace between older and younger employees in Slovenian companies. The main goal of this paper is to present the importance of age diversity and their ag...

Habitual fat intake predicts memory function in younger women

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Edward Leigh eGibson

2013-12-01

Full Text Available High intakes of fat have been linked to greater cognitive decline in old age, but such associations may already occur in younger adults. We tested memory and learning in 38 women (25-45 years old, recruited for a larger observational study in women with polycystic ovary syndrome. These women varied in health status, though not significantly between cases (n=23 and controls (n=15. Performance on tests sensitive to medial temporal lobe function (CANTABeclipse, Cambridge Cognition Ltd., i.e. verbal memory, visuo-spatial learning and delayed pattern matching, were compared with intakes of macronutrients from 7-day diet diaries and physiological indices of metabolic syndrome. Partial correlations were adjusted for age, activity and verbal IQ (National Adult Reading Test. Greater intakes of saturated and trans fats, and higher saturated to unsaturated fat ratio (Sat:UFA, were associated with more errors on the visuo-spatial task and with poorer word recall and recognition. Unexpectedly, higher UFA intake predicted poorer performance on the word recall and recognition measures. Fasting insulin was positively correlated with poorer word recognition only, whereas higher blood total cholesterol was associated only with visuo-spatial learning errors. None of these variables predicted performance on a delayed pattern matching test. The significant nutrient-cognition relationships were tested for mediation by total energy intake: saturated and trans fat intakes, and Sat:UFA, remained significant predictors specifically of visuo-spatial learning errors, whereas total fat and UFA intakes now predicted only poorer word recall. Examination of associations separately for mono- (MUFA and polyunsaturated fats suggested that only MUFA intake was predictive of poorer word recall. Saturated and trans fats, and fasting insulin, may already be associated with cognitive deficits in younger women. The findings need extending but may have important implications for public

A transversal pilot study of oropharyngeal carriage of Kingella kingae in healthy children younger than 6 months.

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Spyropoulou, Vasiliki; Brändle, Gabriel; Maggio, Albane Bertha Rosa; Anderson Della Llana, Rebecca; Cherkaoui, Abdessalam; Renzi, Gesuele; Schrenzel, Jacques; Manzano, Sergio; Ceroni, Dimitri

2017-12-01

The aim of this pilot study was to investigate the extent of oropharyngeal Kingella kingae carriage during the first 6 months of life. We conducted a monocentric transversal pilot study on healthy children younger than 6 months in order to define the oropharyngeal carriage rate. Participants were recruited between December 2013 and September 2015 among children without symptoms or signs of invasive infections. We demonstrated an oropharyngeal carriage rate of 0.67% in children younger than 6 months. Due to the really low carriage rate, it was not possible to draw statistically significant conclusion about any other characteristic of our population. The present study suggests that the oropharyngeal carriage of Kingella kingae among a Swiss population of healthy infants younger than 6 months is exceptional. The scarcity of colonization and disease in the early months of life suggests thus that defense against mucosal carriage and invasive infection is above all provided by vertically acquired immunity. Limited exposure of the neonates due to limited social contacts may also represent another factor avoiding neonates' mucosal Kingella kingae carriage.

Diabetes Mellitus and Younger Age Are Risk Factors for Hyperphosphatemia in Peritoneal Dialysis Patients

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Rameez Imtiaz

2017-02-01

Full Text Available Hyperphosphatemia has been associated with adverse outcomes in patients with end stage kidney disease (ESKD. The purpose of this study was to determine risk factors for hyperphosphatemia in ESKD patients treated with peritoneal dialysis (PD. This information will be used to develop a patient specific phosphate binder application to facilitate patient self-management of serum phosphate. Adult PD patients documented their food, beverage, and phosphate binder intake for three days using a dietitian developed food journal. Phosphate content of meals was calculated using the ESHA Food Processor SQL Software (ESHA Research, Salem, UT, USA. Clinic biochemistry tests and an adequacy assessment (Baxter Adequest program were done. Univariate logistic regression was used to determine predictors of serum phosphate >1.78 mmol/L. A multivariable logistic regression model was then fit including those variables that achieved a significance level of p < 0.20 in univariate analyses. Sixty patients (38 men, 22 women completed the protocol; they were 60 ± 17 years old, 50% had a history of diabetes mellitus (DM and 33% had hyperphosphatemia (PO4 > 1.78 mmol/L. In univariate analysis, the variables associated with an increased risk of hyperphosphatemia with a p-value < 0.2 were male gender (p = 0.13, younger age (0.07, presence of DM (0.005, higher dose of calcium carbonate (0.08, higher parathyroid serum concentration (0.08, lower phosphate intake (0.03, lower measured glomerular filtration rate (0.15, higher phosphate excretion (0.11, and a higher body mass index (0.15. After multivariable logistic regression analysis, younger age (odds ratio (OR 0.023 per decade, 95% confidence interval (CI 0.00065 to 0.455; p = 0.012, presence of diabetes (OR 11.40, 95 CI 2.82 to 61.55; p = 0.0003, and measured GFR (OR 0.052 per mL/min decrease; 95% CI 0.0025 to 0.66 were associated with hyperphosphatemia. Our results support that younger age and diabetes mellitus are

EXPLAINING THE GAP IN ANTENATAL CARE SERVICE UTILIZATION BETWEEN YOUNGER AND OLDER MOTHERS IN GHANA.

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Boamah, Sheila A; Amoyaw, Jonathan; Luginaah, Isaac

2016-05-01

Over two-thirds of pregnant women (69%) have at least one antenatal care (ANC) coverage contact in sub-Saharan Africa. However, to achieve the full life-saving potential that ANC promises for women and babies, a nuanced understanding of age-specific gaps in utilization of ANC services is required. Using the 2008 Ghana Demographic and Health Survey of 1456 individuals, this study examined the disparities in the use of ANC services between younger and older mothers by applying four counterfactual decomposition techniques. The results show that cross-group differences in the explanatory variables largely account for the differentials in ANC service utilization between younger and older mothers. Birth order (parity) accounts for the largest share of the contribution to the overall explained gap in ANC utilization between the younger and older mothers, suggesting that ANC differentials between the two groups are probably due to biosocial factors. To a lesser extent, wealth status of the two groups also contributes to the overall explained gap in ANC service utilization. The policy implications of these findings are that in order to bridge the ANC service utilization gap between the two groups, policymakers must systematically address gaps in cross-group differences in the explanatory variables in order to increase the utilization of ANC to attain the minimum recommendation of four visits as per World Health Organization guidelines.

Indications of CT scan after minor head trauma in children. Can age younger than 2 years be a risk factor?

International Nuclear Information System (INIS)

Ozaki, Mitsunori; Seo, Yoshinobu; Nakamura, Hirohiko

2010-01-01

The indications of CT scan after minor head trauma in children are often discussed, including risks of radiation-induced malignancy. Our aim is to identify whether children younger than 2 years have greater risk of traumatic brain injury compared to older children. We enrolled and analysed 1,830 patients younger than 7 years who underwent CT scans after head trauma in our institute. Patients without any symptoms (n=916) were defined as Group A (age<2: n=391, age 2-6: n=525). Patients with extracranial traumatic findings such as scalp hematoma or laceration, and without any neurological symptoms (n=600) were defined as Group B (age<2: n=163, age 2-6: n=437). In order to analyze whether children younger than 2 years have risks of abnormal CT findings due to head trauma, we used the chi-square test in both Group A and Group B. A P-value of less than 0.05 was considered statistically significant. In Group A, there was no significant difference in the frequency of abnormal CT findings between the younger and older groups (p=0.526). In Group B, however, there was a significant difference between those groups (p=0.0186). We suggest that, based on our findings, children younger than 2 years without any symptoms don't have a greater risk of brain injury compared to older children after minor head trauma. This study might contribute to save those children from receiving unnecessary radiation. (author)

Hormone therapy affects plasma measures of factor VII-activating protease in younger postmenopausal women

DEFF Research Database (Denmark)

Mathiasen, Jørn Sidelmann; Skouby, S.O.; Vitzthum, F.

2010-01-01

Objectives Current reviews indicate that hormone therapy (HT) has a protective role in coronary heart disease (CHD) in younger postmenopausal women, whereas HT contributes to CHD in older women Factor VII-activating protease (FSAP) is a serine protease that accumulates in unstable atherosclerotic...

Radioactive iodine therapy for patients with Graves' disease aged 18 or younger

International Nuclear Information System (INIS)

Ogawa, Takahiro; Goshi, Kazuto; Tajiri, Junichi

2008-01-01

There have been few reports concerning radioactive iodine therapy (RI therapy) for Graves' disease in children, even in the United States of America (USA), and there have been no reports of such treatment in Japan. We evaluated the short-term results of RI therapy for Graves' disease aged 18 or younger. A total of 36 patients (10 male and 26 female) with Graves' disease, aged 18 and younger (range, 13 to 18 years; mean age, 15.8±1.5 years), received RI therapy on an outpatient basis at our clinic between July 1999 and July 2005. The mean interval from initiation of an antithyroid drug (ATD) to RI therapy was 25.3±21.5 months (range, 1 to 78 months). Twenty patients received therapy once, 14 twice, and 2 three times. The mean initial dose of radioactive iodine was 7.8±2.9 mCi (range, 3.6 to 13.0 mCi) and the mean total dose was 12.3±7.7 mCi (range, 3.6 to 29.8 mCi). The mean estimated weight of the thyroid gland was 42.6±23.4 g (range, 15.5 to 99.4 g) before RI therapy and 7.1±3.0 g (range, 2.0 to 13.6 g) after RI therapy. The mean follow-up period after RI therapy was 41.1±18.0 months (range, 6 to 71 months). Currently, 15 patients (42%) have hypothyroidism, 8 (22%) have subclinical hypothyroidism, 5 (14%) have euthyroidism, and 8 (22%) have subclinical hyperthyroidism. Patients taking thyroid hormone were considered hypothyroid. Patients with subclinical hypothyroidism are currently being monitored without treatment. No patients with subclinical hyperthyroidism are taking an ATD or KI (potassium iodide). A total of 36 patients with Graves' disease, aged 18 and younger, received RI therapy, and the short-term outcome in these patients were favorable. However, prolonged follow-up observation is required to confirm long-term safety. (author)

Valuation of active blind spot detection systems by younger and older adults.

Science.gov (United States)

Souders, Dustin J; Best, Ryan; Charness, Neil

2017-09-01

Due to their disproportional representation in fatal crashes, younger and older drivers both stand to benefit from in-vehicle safety technologies, yet little is known about how they value such technologies, or their willingness to adopt them. The current study investigated older (aged 65 and greater; N=49) and younger (ages 18-23; N=40) adults' valuation of a blind spot monitor and asked if self-reported visual difficulties while driving predicted the amount participants were willing to pay for a particular system (BMW's Active Blind Spot Detection System) that was demonstrated using a short video. Large and small anchor values ($250 and $500, respectively) were used as between subjects manipulations to examine the effects of initial valuation, and participants proceeded through a short staircase procedure that offered them either the free installation of the system on their current vehicle or a monetary prize ($25-$950) that changed in value according to which option they had selected in the previous step of the staircase procedure. Willingness to use other advanced driver assistance systems (lane-departure warning, automatic lane centering, emergency braking, adaptive cruise control, and self-parking systems) was also analyzed, additionally controlling for prior familiarity of those systems. Results showed that increased age was associated with a higher valuation for the Active Blind Spot Detection System in both the large and small anchor value conditions controlling for income, gender, and technology self-efficacy. Older adults valued blind spot detection about twice as much ($762) as younger adults ($383) in the large anchor condition, though both groups' values were in the range for the current cost of an aftermarket system. Similarly, age was the most robust positive predictor of willingness to adopt other driving technologies, along with system familiarity. Difficulties with driving-related visual factors also positively predicting acceptance levels for

Otitis media with effusion in children younger than 1 year

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Renata Cantisani Di Francesco

2016-06-01

Full Text Available Abstract Objective: To determine the prevalence of otitis media with effusion in children younger than 1 year and its association with the season of the year, artificial feeding, environmental and perinatal factors. Methods: Retrospective study of 184 randomly included medical records from a total of 982 healthy infants evaluated for hearing screening tests. Diagnosis of otitis media with effusion was based on otoscopy (amber-gold color, fluid level, handle of malleus position, type B tympanometric curves and absence of otoacoustic emissions. Incomplete medical records or those describing acute otitis media, upper respiratory tract infections on the assessment day or in the last 3 months, neuropathies and craniofacial anomalies were excluded. Data such as gestational age, birth weight, Apgar score, type of feeding and day care attendance were compared between children with and without otitis media with effusion through likelihood tests and multivariate analysis. Results: 25.3% of 184 infants had otitis media with bilateral effusion; 9.2% had unilateral. In infants with otitis media, the following were observed: chronological age of 9.6±1.7 months; gestational age >38 weeks in 43.4% and birth weight >2500g in 48.4%. Otitis media with effusion was associated with winter/fall, artificial feeding, Apgar score <7 and day care attendance. The multivariate analysis showed that artificial feeding is the factor most often associated to otitis media with effusion. Conclusions: Otitis media with effusion was found in about one third of children younger than 1 year and was mainly associated with artificial feeding.

Designing an information search interface for younger and older adults.

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Pak, Richard; Price, Margaux M

2008-08-01

The present study examined Web-based information retrieval as a function of age for two information organization schemes: hierarchical organization and one organized around tags or keywords. Older adults' performance in information retrieval tasks has traditionally been lower compared with younger adults'. The current study examined the degree to which information organization moderated age-related performance differences on an information retrieval task. The theory of fluid and crystallized intelligence may provide insight into different kinds of information architectures that may reduce age-related differences in computer-based information retrieval performance. Fifty younger (18-23 years of age) and 50 older (55-76 years of age) participants browsed a Web site for answers to specific questions. Half of the participants browsed the hierarchically organized system (taxonomy), which maintained a one-to-one relationship between menu link and page, whereas the other half browsed the tag-based interface, with a many-to-one relationship between menu and page. This difference was expected to interact with age-related differences in fluid and crystallized intelligence. Age-related differences in information retrieval performance persisted; however, a tag-based retrieval interface reduced age-related differences, as compared with a taxonomical interface. Cognitive aging theory can lead to interface interventions that reduce age-related differences in performance with technology. In an information retrieval paradigm, older adults may be able to leverage their increased crystallized intelligence to offset fluid intelligence declines in a computer-based information search task. More research is necessary, but the results suggest that information retrieval interfaces organized around keywords may reduce age-related differences in performance.

Typography manipulations can affect priming of word stem completion in older and younger adults.

Science.gov (United States)

Gibson, J M; Brooks, J O; Friedman, L; Yesavage, J A

1993-12-01

The experiments reported here investigated whether changes of typography affected priming of word stem completion performance in older and younger adults. Across all experiments, the typeface in which a word appeared at presentation either did or did not match that of its 3-letter stem at test. In Experiment 1, no significant evidence of a typography effect was found when words were presented with a sentence judgment or letter judgment task. However, subsequent experiments revealed that, in both older and younger adults, only words presented with a syllable judgment task gave rise to the typography effect (Experiments 2-4). Specifically, performance was greater, when the presentation and test typeface matched than when they did not. Experiment 5, which used stem-cued recall, did not reveal a difference between syllable and letter judgment tasks. These findings highlight the complex nature of word stem completion performance.

The circumvention of obstacles during walking in different environmental contexts: a comparison between older and younger adults.

Science.gov (United States)

Gérin-Lajoie, Martin; Richards, Carol L; McFadyen, Bradford J

2006-11-01

Avoiding pedestrians is an integral part of our daily activities, yet this locomotor activity has received little attention in gait research. A recent study [Motor Control 2005;9:242] described the motor strategies used by young adults to circumvent an obstruction in different environmental contexts including obstacle movement, certainty about this obstacle movement and auditory distractions. The relationship between normal aging and such locomotor activity within these different environmental contexts, however, is not known. The purpose of this study was thus to compare the walking speed and the personal space-a protective zone preserved around the body-in healthy younger and older adults during obstacle circumvention in the above mentioned environmental contexts. The movements of nine younger adults (24.6+/-4.1 years) and nine older adults (69.7+/-3.2 years) were measured as they circumvented a stationary or moving mannequin with and without initial knowledge of the obstacle's displacements. Participants also had to pay attention to auditory messages, played in half of the trials, and to answer related questions. Results showed that all three environmental factors resulted in decreased gait speed in both groups, but the effect of auditory distractions was greater in older adults. Older adults also increased their personal space more than younger adults while paying attention to messages and they made more mistakes when answering related questions. Therefore, even if such an avoidance task is performed routinely, the increased information processing demanded by the environmental context affected both the motor and cognitive performance of older adults more than that of younger adults. Copyright 2005 Elsevier B.V.

Risk of traumatic brain injuries in children younger than 24 months with isolated scalp hematomas.

Science.gov (United States)

Dayan, Peter S; Holmes, James F; Schutzman, Sara; Schunk, Jeffrey; Lichenstein, Richard; Foerster, Lillian A; Hoyle, John; Atabaki, Shireen; Miskin, Michelle; Wisner, David; Zuspan, SallyJo; Kuppermann, Nathan

2014-08-01

We aimed to determine the association between scalp hematoma characteristics and traumatic brain injuries in young children with blunt head trauma who have no other symptoms or signs suggestive of traumatic brain injuries (defined as "isolated scalp hematomas"). This was a secondary analysis of children younger than 24 months with minor blunt head trauma from a prospective cohort study in 25 Pediatric Emergency Care Applied Research Network emergency departments. Treating clinicians completed a structured data form. For children with isolated scalp hematomas, we determined the prevalence of and association between scalp hematoma characteristics and (1) clinically important traumatic brain injury (death, neurosurgery for traumatic brain injury, intubation >24 hours for traumatic brain injury, or positive computed tomography (CT) scan in association with hospitalization ≥2 nights for traumatic brain injury); and (2) traumatic brain injury on CT. Of 10,659 patients younger than 24 months were enrolled, 2,998 of 10,463 (28.7%) with complete data had isolated scalp hematomas. Clinically important traumatic brain injuries occurred in 12 patients (0.4%; 95% confidence interval [CI] 0.2% to 0.7%); none underwent neurosurgery (95% CI 0% to 0.1%). Of 570 patients (19.0%) for whom CTs were obtained, 50 (8.8%; 95% CI 6.6% to 11.4%) had traumatic brain injuries on CT. Younger age, non-frontal scalp hematoma location, increased scalp hematoma size, and severe injury mechanism were independently associated with traumatic brain injury on CT. In patients younger than 24 months with isolated scalp hematomas, a minority received CTs. Despite the occasional presence of traumatic brain injuries on CT, the prevalence of clinically important traumatic brain injuries was very low, with no patient requiring neurosurgery. Clinicians should use patient age, scalp hematoma location and size, and injury mechanism to help determine which otherwise asymptomatic children should undergo

Diagnostic testing for serious bacterial infections in infants aged 90 days or younger with bronchiolitis.

Science.gov (United States)

Liebelt, E L; Qi, K; Harvey, K

1999-05-01

To describe the different laboratory tests that are performed on young infants aged 90 days or younger with bronchiolitis and to identify historical and clinical predictors of infants on whom laboratory tests are performed. Cross-sectional study whereby information was obtained by retrospective review of medical records from November through March 1992 to 1995 of all infants with a clinical diagnosis of bronchiolitis. Urban pediatric emergency department. Two hundred eleven consecutive infants aged 90 days or younger (median age, 54 days) with 216 episodes of bronchiolitis. Historical and clinical data on each infant in addition to laboratory data that included a white blood cell count, urinalysis, and blood, urine, and cerebrospinal fluid cultures. Two or more laboratory tests (not including chest radiographs) were obtained in 48% of all infants and 78% of febrile infants. Of the 91 infants with a history of a temperature of 38.0 degrees C or more or temperature on presentation of 38.0 degrees C or more, white blood cell counts were obtained in 77%, blood cultures in 75%, urinalyses in 53%, urine cultures in 60%, and analyses-cultures of cerebrospinal fluid in 47%. Febrile infants were 10 times more likely to get at least 2 laboratory tests than afebrile infants (Ppredictors of whether laboratory studies were obtained. History of preterm gestation, aged younger than 28 days, previous antibiotic use, and presence of otitis media were not associated with obtainment of laboratory studies. No cases of bacteremia, urinary tract infection, or meningitis were found among all infants with bronchiolitis who had blood, urine, and/or cerebrospinal fluid cultures. There is wide variability in the diagnostic testing of infants aged 90 days or younger with bronchiolitis. The risks of bacteremia, urinary tract infection, and meningitis in infants with bronchiolitis seems to be low. History or a documented temperature of 38.0 degrees C or more; oxygen saturation of less than 92

Is Pornography Use Associated with Sexual Difficulties and Dysfunctions among Younger Heterosexual Men?

Science.gov (United States)

Landripet, Ivan; Štulhofer, Aleksandar

2015-05-01

Recent epidemiological studies reported high prevalence rates of erectile dysfunction (ED) among younger heterosexual men (≤40). It has been suggested that this "epidemic" of ED is related to increased pornography use. However, empirical evidence for such association is currently lacking. This study analyzes associations between pornography use and sexual health disturbances among younger heterosexual men using four large-scale online samples from three European countries. The analyses were carried out using a 2011 cross-sectional online study of Croatian, Norwegian, and Portuguese men (Study 1; N = 2,737) and a 2014 cross-sectional online study of Croatian men (Study 2; N = 1,211). Chi-square test and multivariate logistic regression were used to explore the associations between pornography use and sexual difficulties. In Study 1, erectile difficulties, inability to reach orgasm, and a lack of sexual desire were measured using the Global Study of Sexual Attitudes and Behavior indicators. In Study 2, ED was measured with the abridged International Index of Erectile Function (IIEF-5). Delayed ejaculation and a decrease of sexual desire were assessed with one-item indicators. In Study 1, only the relationship between pornography use and ED among Croatian men was statistically significant (χ(2) [2] = 18.76, P pornography, moderate but not high frequency of pornography use increased the odds of reporting ED (adjusted odds ratio = 0.53, P pornography use and male sexual dysfunctions were observed. We found little evidence of the association between pornography use and male sexual health disturbances. Contrary to raising public concerns, pornography does not seem to be a significant risk factor for younger men's desire, erectile, or orgasmic difficulties. © 2015 International Society for Sexual Medicine.

Burnout of Older and Younger Employees – The Case of Slovenia

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Rožman Maja

2017-02-01

Full Text Available Background and Purpose: People spend a significant part of their lifespan working, but the role of age in job design and implementation of work have largely been ignored. The consequences can be evident in stress and burnout in different symptoms. Thus, age-diverse employees are faced with different symptoms of burnout and stress when carrying out their work. The main aim of this paper is to present burnout of older employees compared to younger employees in Slovenian companies.

Greater BOLD variability in older compared with younger adults during audiovisual speech perception.

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Sarah H Baum

Full Text Available Older adults exhibit decreased performance and increased trial-to-trial variability on a range of cognitive tasks, including speech perception. We used blood oxygen level dependent functional magnetic resonance imaging (BOLD fMRI to search for neural correlates of these behavioral phenomena. We compared brain responses to simple speech stimuli (audiovisual syllables in 24 healthy older adults (53 to 70 years old and 14 younger adults (23 to 39 years old using two independent analysis strategies: region-of-interest (ROI and voxel-wise whole-brain analysis. While mean response amplitudes were moderately greater in younger adults, older adults had much greater within-subject variability. The greatly increased variability in older adults was observed for both individual voxels in the whole-brain analysis and for ROIs in the left superior temporal sulcus, the left auditory cortex, and the left visual cortex. Increased variability in older adults could not be attributed to differences in head movements between the groups. Increased neural variability may be related to the performance declines and increased behavioral variability that occur with aging.

Combined oral contraceptives' influence on weight, body composition, height, and bone mineral density in girls younger than 18 years

DEFF Research Database (Denmark)

Warholm, Lina; Petersen, Kresten R; Ravn, Pernille

2012-01-01

Combined oral contraceptives (COCs) are increasingly used by adolescents. The aim of this review is to investigate the evidence regarding COCs' influence on weight, height and bone mineral density (BMD) in girls younger than 18 years.......Combined oral contraceptives (COCs) are increasingly used by adolescents. The aim of this review is to investigate the evidence regarding COCs' influence on weight, height and bone mineral density (BMD) in girls younger than 18 years....

Treatment of rape-induced urogenital and lower gastrointestinal lesions among girls aged 5 years or younger.

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Mukwege, Denis; Alumeti, Desiré; Himpens, Jacques; Cadière, Guy-Bernard

2016-03-01

To evaluate outcomes after treatment of rape-induced urogenital and lower gastrointestinal lesions among young girls. In a retrospective study, data were assessed from girls aged 5 years or younger who were treated for sexual-assault-related injuries at the General Referral Hospital, Panzi, Bukavu, Democratic Republic of Congo, between 2004 and 2014. Data were obtained from review of charts, records of the mother's impressions and physical examinations, and photographic evidence. Elective surgery had been reserved for patients experiencing fecal and/or urinary incontinence. Overall, 205 girls aged 5 years or younger presented with rape injuries: 162 (79.1%) had only mucocutaneous lesions, 22 (10.7%) had musculocutaneous lesions, and 21 (10.2%) had musculocutaneous lesions complicated by fecal and/or urinary incontinence. Among the 21 girls who underwent perineal surgery, two with fecal and urinary incontinence and perforation of the peritoneum of Douglas pouch were additionally treated by laparoscopy. Among 16 patients with fecal incontinence, the continence score had improved significantly at 10.4 months after surgery (Prape survivors aged 5 years or younger, a treatment strategy by which surgery is reserved for incontinent patients provided good cosmetic and functional outcomes. Copyright © 2015 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Searching for Extraterrestrial Amino Acids in a Contaminated Meteorite: Amino Acid Analyses of the Canakkale L6 Chondrite

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Burton, A. S.; Elsila, J. E.; Glavin, D. P.; Dworkin, J. P.; Ornek, C. Y.; Esenoglu, H. H.; Unsalan, O.; Ozturk, B.

2016-01-01

Amino acids can serve as important markers of cosmochemistry, as their abundances and isomeric and isotopic compositions have been found to vary predictably with changes in parent body chemistry and alteration processes. Amino acids are also of astrobiological interest because they are essential for life on Earth. Analyses of a range of meteorites, including all groups of carbonaceous chondrites, along with H, R, and LL chondrites, ureilites, and a martian shergottite, have revealed that amino acids of plausible extraterrestrial origin can be formed in and persist after a wide range of parent body conditions. However, amino acid analyses of L6 chondrites to date have not provided evidence for indigenous amino acids. In the present study, we performed amino acid analysis on larger samples of a different L6 chondite, Canakkale, to determine whether or not trace levels of indigenous amino acids could be found. The Canakkale meteor was an observed fall in late July, 1964, near Canakkale, Turkey. The meteorite samples (1.36 and 1.09 g) analyzed in this study were allocated by C. Y. Ornek, along with a soil sample (1.5 g) collected near the Canakkale recovery site.

The high-resolution extraterrestrial solar spectrum (QASUMEFTS determined from ground-based solar irradiance measurements

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J. Gröbner

2017-09-01

Full Text Available A high-resolution extraterrestrial solar spectrum has been determined from ground-based measurements of direct solar spectral irradiance (SSI over the wavelength range from 300 to 500 nm using the Langley-plot technique. The measurements were obtained at the Izaña Atmospheric Research Centre from the Agencia Estatal de Meteorología, Tenerife, Spain, during the period 12 to 24 September 2016. This solar spectrum (QASUMEFTS was combined from medium-resolution (bandpass of 0.86 nm measurements of the QASUME (Quality Assurance of Spectral Ultraviolet Measurements in Europe spectroradiometer in the wavelength range from 300 to 500 nm and high-resolution measurements (0.025 nm from a Fourier transform spectroradiometer (FTS over the wavelength range from 305 to 380 nm. The Kitt Peak solar flux atlas was used to extend this high-resolution solar spectrum to 500 nm. The expanded uncertainties of this solar spectrum are 2 % between 310 and 500 nm and 4 % at 300 nm. The comparison of this solar spectrum with solar spectra measured in space (top of the atmosphere gave very good agreements in some cases, while in some other cases discrepancies of up to 5 % were observed. The QASUMEFTS solar spectrum represents a benchmark dataset with uncertainties lower than anything previously published. The metrological traceability of the measurements to the International System of Units (SI is assured by an unbroken chain of calibrations leading to the primary spectral irradiance standard of the Physikalisch-Technische Bundesanstalt in Germany.

Inhabited or Uninhabited? Pitfalls in the Interpretation of Possible Chemical Signatures of Extraterrestrial Life

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Stefan Fox

2017-08-01

Full Text Available The “Rare Earth” hypothesis—put forward by Ward and Brownlee in their 2000 book of the same title—states that prokaryote-type organisms may be common in the universe but animals and higher plants are exceedingly rare. If this idea is correct, the search for extraterrestrial life is essentially the search for microorganisms. Various indicators may be used to detect extant or extinct microbial life beyond Earth. Among them are chemical biosignatures, such as biomolecules and stable isotope ratios. The present minireview focuses on the major problems associated with the identification of chemical biosignatures. Two main types of misinterpretation are distinguished, namely false positive and false negative results. The former can be caused by terrestrial biogenic contaminants or by abiotic products. Terrestrial contamination is a common problem in space missions that search for biosignatures on other planets and moons. Abiotic organics can lead to false positive results if erroneously interpreted as biomolecules, but also to false negatives, for example when an abiotic source obscures a less productive biological one. In principle, all types of putative chemical biosignatures are prone to misinterpretation. Some, however, are more reliable (“stronger” than others. These include: (i homochiral polymers of defined length and sequence, comparable to proteins and polynucleotides; (ii enantiopure compounds; (iii the existence of only a subset of molecules when abiotic syntheses would produce a continuous range of molecules; the proteinogenic amino acids constitute such a subset. These considerations are particularly important for life detection missions to solar system bodies such as Mars, Europa, and Enceladus.

Mechanisms for the inversion of chirality: Global reaction route mapping of stereochemical pathways in a probable chiral extraterrestrial molecule, 2-aminopropionitrile

International Nuclear Information System (INIS)

Kaur, Ramanpreet; Vikas

2015-01-01

2-Aminopropionitrile (APN), a probable candidate as a chiral astrophysical molecule, is a precursor to amino-acid alanine. Stereochemical pathways in 2-APN are explored using Global Reaction Route Mapping (GRRM) method employing high-level quantum-mechanical computations. Besides predicting the conventional mechanism for chiral inversion that proceeds through an achiral intermediate, a counterintuitive flipping mechanism is revealed for 2-APN through chiral intermediates explored using the GRRM. The feasibility of the proposed stereochemical pathways, in terms of the Gibbs free-energy change, is analyzed at the temperature conditions akin to the interstellar medium. Notably, the stereoinversion in 2-APN is observed to be more feasible than the dissociation of 2-APN and intermediates involved along the stereochemical pathways, and the flipping barrier is observed to be as low as 3.68 kJ/mol along one of the pathways. The pathways proposed for the inversion of chirality in 2-APN may provide significant insight into the extraterrestrial origin of life

Perceived barriers to physical activity in older and younger veterans with serious mental illness.

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Muralidharan, Anjana; Klingaman, Elizabeth A; Molinari, Victor; Goldberg, Richard W

2018-03-01

Individuals with serious mental illness endorse many more medical and psychosocial barriers to physical activity (PA) than the general population. However, it is unknown if older adults with serious mental illness are at greater risk of experiencing barriers to PA than their younger counterparts. The present study utilized a national VA dataset to compare veterans with serious mental illness ages 55 and older (n = 9,044) to veterans with serious mental illness ages 54 and younger (n = 8,782) on their responses to a questionnaire assessment of barriers to PA. Older veterans were more likely to endorse arthritis and cardiopulmonary disease, and less likely to endorse work schedule, as barriers to PA. Interventions designed to increase PA for young/middle-aged adults with serious mental illness may be broadly useful for older adults with serious mental illness, with some modification to address specific health concerns. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

A Prospective Comparison of Younger and Older Patients' Preferences for Adjuvant Chemotherapy and Hormonal Therapy in Early Breast Cancer.

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Hamelinck, Victoria C; Bastiaannet, Esther; Pieterse, Arwen H; de Glas, Nienke A; Portielje, Johanneke E A; Merkus, Jos W S; den Hoed, Irma D M; van de Velde, Cornelis J H; Liefers, Gerrit-Jan; Stiggelbout, Anne M

2016-10-01

It is unknown what minimal benefit in disease-free survival older patients with breast cancer require from adjuvant systemic therapy, and if this differs from that required by younger patients. We prospectively examined patients' preferences for adjuvant chemotherapy (aCT) and adjuvant hormonal therapy (aHT), factors related to minimally-required benefit, and patients' self-reported motivations. Fifty-two younger (40-64 years) and 29 older (≥ 65 years) women with a first primary, invasive tumor were interviewed post-surgery, prior to receiving aCT/aHT recommendation. The proportions of younger versus older participants who would accept, refuse, or were undecided about therapy were 92% versus 62%, 4% versus 24%, and 4% versus 14% for aCT, and 92% versus 59%, 8% versus 17%, and 0% versus 24% for aHT. The proportion of older participants who would refuse rather than accept aCT was larger than that of younger participants (P = .005). No significant difference was found for aHT (P = .12). Younger and older participants' minimally-required benefit, in terms of additional 10-year disease-free survival, to accept aCT (median, 5% vs. 4%; P = .13) or aHT (median, 10% vs. 8%; P = .15) did not differ. Being single/divorced/widowed (odds ratio [OR], 0.16; P = .005), presence of geriatric condition (inability to perform daily activities, incontinence, severe sensory impairment, depression, polypharmacy, difficulties with walking; OR, 0.27; P = .047), and having a preference to make the treatment decision either alone or after considering the clinician's opinion (active role; OR, 0.15; P = .012) were independently related to requiring larger benefits from aCT. The most frequent motivations for/against therapy included the wish to survive/avoid recurrence, clinician's recommendation, side effects, and treatment duration (only aHT). Whereas older participants were less willing to accept aCT than younger participants, no significant difference was found for aHT. However, a

Preferred and Perceived Participation of Younger and Older Patients in Decision Making About Treatment for Early Breast Cancer: A Prospective Study.

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Hamelinck, Victoria C; Bastiaannet, Esther; Pieterse, Arwen H; van de Velde, Cornelis J H; Liefers, Gerrit-Jan; Stiggelbout, Anne M

2018-04-01

Older patients are believed to prefer a more passive role in treatment decision making, but studies reporting this relation were conducted over a decade ago or were retrospective. We prospectively compared younger (40-64 years) versus older (≥ 65 years) breast cancer patients' preferences for decision-making roles and their perceived actual roles. A prospective multicenter study was conducted in Leiden, The Hague, and Tilburg over a 2-year period. Early-stage breast cancer patients were surveyed about their preferred and perceived decision-making roles (active, shared, or passive) concerning surgery type (breast-conserving vs. mastectomy) (n = 74), adjuvant chemotherapy (aCT, n = 43), and adjuvant hormonal therapy (aHT, n = 39). For all decisions, both age groups most frequently preferred a shared role before consultation, except for decisions about aHT, for which younger patients more commonly preferred an active role. The proportion of patients favoring an active or passive role in each decision was lower for the older than the younger patients, but none of the differences was significant. Regarding perceived actual roles, both groups most frequently reported an active role in the surgical decision after consultation. In deciding about both aCT and aHT, a larger proportion of older patients perceived having had a passive role compared to younger patients, and a greater proportion of younger patients perceived having been active. Again, differences were not statistically significant. Most older patients preferred to decide together with their clinician, but preferences varied widely. Older patients more often than younger patients perceived they had not been involved in decisions about systemic therapy. Clinicians should invite all patients to participate in decision making and elicit their preferred role. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Social and pedagogical aspects of religious literacy among the younger generation

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Efimov Vladimir Fedorovich

2015-07-01

Full Text Available The article reveals the problem of the education of youth in religious issues through the activities of the Church and secular educational institutions. The author shows the absolute failure of the efforts of the state and the Church in this direction that causes damage to the moral education of the younger generation. The author enlightens the originality, specificity, criticism of the interaction between the Church and the intelligentsia, and also the organizational ways of formation of the religious literacy among the population of Russia.

Acute stress disorder in older, middle-aged and younger adults in reaction to the second Lebanon war.

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Cohen, Miri

2008-01-01

To compare rate of acute stress disorder (ASD) and intensity of acute stress symptoms (ASS) in younger, middle-aged and older Israeli citizens exposed to missile attacks during the second Lebanon war. A telephone survey of a random sample of residents in the northern area of Israel was conducted in July 2006, during the third week of Lebanon war. Respondents were divided into groups aged 18-40, 41-69 and 70+. ASD and ASS were measured by the Acute Stress Interview questionnaire and by war-related exposure variables and demographic data. Exposure variables were similar in the three age groups. Older respondents reported lower intensity of ASS and obtained lower means for each of the symptoms criteria than the young adults, while the middle-aged adults were in between the younger and the older group. ASD criteria were met by 13.2% of the younger, 4.7% of middle-aged and 4.3% of older respondents (p > 0.05), and subsyndromal ASD was found in 20.5%, 14.1% and 4.4% (p war situation with lower level of acute stress symptoms. Long-term effects of war on different age groups should be further studied.

Genesis of Uranium in the younger granites of gabal abu hawis area, central eastern desert of Egypt

International Nuclear Information System (INIS)

Ahmed, F.Y.; Moharem, A.F.

2003-01-01

The younger granites cropping out in gabal abu hawis area are considered as uraniferous (fertile) granites (the fertile is mainly is mainly attributed to presence of radioactive zircon). Abu hawis granitic pluton is dissected by joints faults of different trends forming two mineralized shear zones in the northern peripheries and southern border. The younger granites hosting uranium mineralizations along the two mineralized shear zones. The uranium minerals include uranophane and carnotite. The altered granites have much lower Th/U ratios (0.03-0.10) than those of the fresh granites (1.69-2.05), indicating strong mobilization of uranium in this pluton by super-heated solutions that resulted from supergence meteoric water as well as U-addition by hypogene fluids. These solutions could pass through the structural network of fractures, joints and fault planes and have leached some of labile uranium from the surrounding rocks and/or the younger granites themselves. Then, changing in the physicochemical conditions of these solutions caused uranium precipitation as uranium minerals filling the cracks in the rock and/or adsorbed on the surface of clay minerals and iron oxides in the two shear zones

Spatial-Sequential Working Memory in Younger and Older Adults: Age Predicts Backward Recall Performance within Both Age Groups

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Brown, Louise A.

2016-01-01

Working memory is vulnerable to age-related decline, but there is debate regarding the age-sensitivity of different forms of spatial-sequential working memory task, depending on their passive or active nature. The functional architecture of spatial working memory was therefore explored in younger (18–40 years) and older (64–85 years) adults, using passive and active recall tasks. Spatial working memory was assessed using a modified version of the Spatial Span subtest of the Wechsler Memory Scale – Third Edition (WMS-III; Wechsler, 1998). Across both age groups, the effects of interference (control, visual, or spatial), and recall type (forward and backward), were investigated. There was a clear effect of age group, with younger adults demonstrating a larger spatial working memory capacity than the older adults overall. There was also a specific effect of interference, with the spatial interference task (spatial tapping) reliably reducing performance relative to both the control and visual interference (dynamic visual noise) conditions in both age groups and both recall types. This suggests that younger and older adults have similar dependence upon active spatial rehearsal, and that both forward and backward recall require this processing capacity. Linear regression analyses were then carried out within each age group, to assess the predictors of performance in each recall format (forward and backward). Specifically the backward recall task was significantly predicted by age, within both the younger and older adult groups. This finding supports previous literature showing lifespan linear declines in spatial-sequential working memory, and in working memory tasks from other domains, but contrasts with previous evidence that backward spatial span is no more sensitive to aging than forward span. The study suggests that backward spatial span is indeed more processing-intensive than forward span, even when both tasks include a retention period, and that age predicts

Spatial-sequential working memory in younger and older adults: age predicts backward recall performance within both age groups

Directory of Open Access Journals (Sweden)

Louise A. Brown

2016-10-01

Full Text Available Working memory is vulnerable to age-related decline, but there is debate regarding the age-sensitivity of different forms of spatial-sequential working memory task, depending on their passive or active nature. The functional architecture of spatial working memory was therefore explored in younger (18-40 years and older (64-85 years adults, using passive and active recall tasks. Spatial working memory was assessed using a modified version of the Spatial Span subtest of the Wechsler Memory Scale – Third Edition (WMS-III; Wechsler, 1998. Across both age groups, the effects of interference (control, visual, or spatial, and recall type (forward and backward, were investigated. There was a clear effect of age group, with younger adults demonstrating a larger spatial working memory capacity than the older adults overall. There was also a specific effect of interference, with the spatial interference task (spatial tapping reliably reducing performance relative to both the control and visual interference (dynamic visual noise conditions in both age groups and both recall types. This suggests that younger and older adults have similar dependence upon active spatial rehearsal, and that both forward and backward recall require this processing capacity. Linear regression analyses were then carried out within each age group, to assess the predictors of performance in each recall format (forward and backward. Specifically the backward recall task was significantly predicted by age, within both the younger and older adult groups. This finding supports previous literature showing lifespan linear declines in spatial-sequential working memory, and in working memory tasks from other domains, but contrasts with previous evidence that backward spatial span is no more sensitive to aging than forward span. The study suggests that backward spatial span is indeed more processing-intensive than forward span, even when both tasks include a retention period, and that age

Spatial-Sequential Working Memory in Younger and Older Adults: Age Predicts Backward Recall Performance within Both Age Groups.

Science.gov (United States)

Brown, Louise A

2016-01-01

Working memory is vulnerable to age-related decline, but there is debate regarding the age-sensitivity of different forms of spatial-sequential working memory task, depending on their passive or active nature. The functional architecture of spatial working memory was therefore explored in younger (18-40 years) and older (64-85 years) adults, using passive and active recall tasks. Spatial working memory was assessed using a modified version of the Spatial Span subtest of the Wechsler Memory Scale - Third Edition (WMS-III; Wechsler, 1998). Across both age groups, the effects of interference (control, visual, or spatial), and recall type (forward and backward), were investigated. There was a clear effect of age group, with younger adults demonstrating a larger spatial working memory capacity than the older adults overall. There was also a specific effect of interference, with the spatial interference task (spatial tapping) reliably reducing performance relative to both the control and visual interference (dynamic visual noise) conditions in both age groups and both recall types. This suggests that younger and older adults have similar dependence upon active spatial rehearsal, and that both forward and backward recall require this processing capacity. Linear regression analyses were then carried out within each age group, to assess the predictors of performance in each recall format (forward and backward). Specifically the backward recall task was significantly predicted by age, within both the younger and older adult groups. This finding supports previous literature showing lifespan linear declines in spatial-sequential working memory, and in working memory tasks from other domains, but contrasts with previous evidence that backward spatial span is no more sensitive to aging than forward span. The study suggests that backward spatial span is indeed more processing-intensive than forward span, even when both tasks include a retention period, and that age predicts