Browsing by Subject "age"

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Age, Depth, and Residual Depth Anomalies in the North Pacific: Implications for Thermal Models of the Lithosphere and Upper Mantle
(Institute for Geophysics, 1986) Renkin, Miriam K.; Sclater, John G.
We present an empirical basement depth versus age relation for the North Pacific Ocean, based on the statistical treatment of an ocean-wide gridded data set. The SYNBAPS bathymetry was averaged into half-degree intervals and corrected for the effects of sediment loading. The resulting basement depths were plotted against ages determined from a revised isochron chart based on a recent compilation of magnetic lineations and various published plate reconstructions. On crust older than 80 Ma, the depths are skewed to the shallow side of the depth versus age distribution by large numbers of seamounts. Therefore the mean and standard deviations are not useful representations of the data. A more appropriate representation is the mode (or greatest concentration of points) and contours around the mode. The contours around the mode show that most ocean floor increases in depth with the square root of age out to crust of 80 Ma. Beyond this the majority of the data oscillates about a line that remains essentially constant as the age in-creases. Approximately 56% of all the data points lie within a + 300m band about the mode. If the sediment thickness data in the older basins of the western North Pacific is correct then the flattening of the depths favor a model in which extra heat is supplied to the base of the lithosphere on older ocean floor. Residual depth anomalies were calculated by removing the depths predicted by such a model. These anomalies correlate with bathymetric features and occur predominantly on crust of 120 and 160 Ma. They account for the rises in the mode at these two ages. The overall subsidence of the ocean floor can be accounted for by the cooling of a thermo-mechanical boundary layer. Correlations between geoid height and depth are evidence that many of the residual depth anomalies result from convective plumes which reset the thermal structure of the lithosphere. It is possible that this process observed at different times after the initial resetting of the isotherms may account for many of the depth anomalies in the western North Pacific.
Backward And Simultaneous Masking Measured In Children With Language-Learning Impairments Who Received Intervention With Fast Forword Or Laureate Learning Systems Software
(2001-08) Marler, Jeffrey A.; Champlin, Craig A.; Gillam, Ronald B.; Marler, Jeffrey A.; Champlin, Craig A.; Gillam, Ronald B.
The developers of a computer-assisted language intervention program called Fast ForWord (FFW) have claimed that their software changes temporal processing abilities as a result of specialized modifications to the acoustic and temporal properties of the speech signal within the program. This pilot study compared changes in auditory temporal processing in children who received FFW training and in children who received training with computer-assisted language intervention programs that were not designed to improve auditory perceptual skills. Four boys with Language-Learning Impairments (LLI) and 3 boys with typical language participated. Two of the boys with LLI received the FFW program, and the other 2 received a bundle of computer-assisted instruction (CAI) programs published by Laureate Language Systems (LLS). The FFW and LLS programs were presented on the same schedule. To assess temporal processing, signal thresholds in backward and simultaneous masking conditions were evaluated just before, during, and immediately after language training. The boys with typically developing language received no training. Children with typical language produced signal thresholds in the backward masking condition that were markedly lower than those in the simultaneous masking condition. This disparity is indicative of normal temporal processing. Conversely, 3 of 4 children with LLI failed to demonstrate a simultaneous-backward difference during baseline. The lack of a difference implies that temporal processing was not normal in these children. The fourth child with LLI had signal thresholds that paralleled those of the children with normal language development. This child also had the mildest form of LLI. Of the 3 children whose temporal processing was abnormal, 2 boys showed decreased signal thresholds in the backward masking condition. However, the improvement was sudden, occurring relatively early in the training sequence, and observed with both treatment programs. The third child with abnormal temporal processing failed to show a change in backward masking at any time during treatment. Over the course of the experiment, signal thresholds for all listeners decreased by similar amounts in both backward and simultaneous masking. Taken together, these results do not support the presence of a program-specific improvement in temporal processing. In addition to the temporal processing deficits revealed by backward masking, group differences in response patterns implicate auditory memory involvement or differences in maintaining attention.
Comparison Of Central Artery And The Elasticity In Swimmers, Runners, Sedentary
(2011-03) Nualnim, Nanitee; Barnes, Jill N.; Tarumi, Tarumi; Renzi, Christopher P.; Tanaka, Hirofumi; Nualnim, Nanitee; Barnes, Jill N.; Tarumi, Tarumi; Renzi, Christopher P.; Tanaka, Hirofumi
Although swimming is one of the most popular, most practiced, and most recommended forms of physical activity, little information is available regarding the influence of regular swimming on vascular disease risks. Using a cross-sectional study design, key measurements of vascular function were performed in middle-aged and older swimmers, runners, and sedentary controls. There were no group differences in age, height, dietary intake, and fasting plasma concentrations of glucose, total cholesterol, and low-density lipoprotein cholesterol. Runners and swimmers were not different in their weekly training volume. Brachial systolic blood pressure and pulse pressure were higher (p < 0.05) in swimmers than in sedentary controls and runners. Runners and swimmers had lower (p < 0.05) carotid systolic blood pressure and carotid pulse pressure than sedentary controls. Carotid arterial compliance was higher (p < 0.05) and p-stiffness index was lower (p < 0.05) in runners and swimmers than in sedentary controls. There were no significant group differences between runners and swimmers. Cardiovagal baroreflex sensitivity was greater (p < 0.05) in runners than in sedentary controls and swimmers and baroreflex sensitivity tended to be higher in swimmers than in sedentary controls (p = 0.07). Brachial artery flow-mediated dilation was significant greater (p < 0.05) in runners compared with sedentary controls and swimmers. In conclusion, our present findings are consistent with the notion that habitual swimming exercise may be an effective endurance exercise for preventing loss in central arterial compliance. (c) 2011 Elsevier Inc. All rights reserved. (Am J Cardiol 2011;107:783-787)
Dynamical Masses of Young M Dwarfs: Masses and Orbital Parameters of GJ 3305 AB, the Wide Binary Companion To the Imaged Exoplanet Host 51 Eri
(2015-11) Montet, Benjamin T.; Bowler, Brendan P.; Shkolnik, Evgenya L.; Deck, Katherine M.; Wang, Ji; Horch, Elliott P.; Liu, Michael C.; Hillenbrand, Lynne A.; Kraus, Adam L.; Charbonneau, David; Kraus, Adam L.
We combine new high resolution imaging and spectroscopy from Keck/NIRC2, Discovery Channel Telescope/DSSI, and Keck/HIRES with published astrometry and radial velocities to measure individual masses and orbital elements of the GJ 3305 AB system, a young (similar to 20 Myr) M+M binary (unresolved spectral type M0) member of the beta Pictoris moving group comoving with the imaged exoplanet host 51 Eri. We measure a total system mass of 1.11 +/- 0.04 M-circle dot, a period of 29.03 +/- 0.50 year, a semimajor axis of 9.78 +/- 0.14 AU, and an eccentricity of 0.19 +/- 0.02. The primary component has a dynamical mass of 0.67 +/- 0.05 M-circle dot and the secondary has a mass of 0.44 +/- 0.05 M-circle dot. The recently updated BHAC15 models are consistent with the masses of both stars to within 1.5 sigma. Given the observed masses the models predict an age of the GJ 3305 AB system of 37 +/- 9 Myr. Based on the observed system architecture and our dynamical mass measurement, it is unlikely that the orbit of 51 Eri b has been significantly altered by the Kozai-Lidov mechanism.
Letter to Curtis J. Hesse from H.B. Stenzel on 1943-08-05
(1943-08-05) Stenzel, Henryk B.
Letter to E.L. Lundelius, Jr. from H.B. Stenzel on 1961-04-14
(1961-04-14) Stenzel, H.B.
Letter to Ernest T. Baker, Jr. from H.B. Stenzel on 1963-06-06
(1963-06-06) Stenzel, Henryk B.
Letter to Gordon Gunter from H.B. Stenzel on 1950-10-02
(1950-10-02) Stenzel, Henryk B.
Letter to H. B. Stenzel from M. N. Broughton on 1938-06-23
(1938-06-23) Broughton, M. N.
Letter to H.B. Stenzel from B.Coleman Renick on 1936-02-29
(1936-02-29) Renick, B.Coleman
Letter to H.B. Stenzel from Charles A. Steen on 1947-03-18
(1947-03-18) Steen, Charles A.
Letter to H.B. Stenzel from Charles E. Weaver on 1944-11-24
(1944-11-24) Weaver, Charles E.
Letter to H.B. Stenzel from Curtis J. Hesse on 1943-08-09
(1943-08-09) Hesse, Curtis J.
Letter to H.B. Stenzel from D.J. Beets on 1964-04-04
(1964-04-04) Beets, D.J.
Letter to H.B. Stenzel from D.J. Beets on 1966-03-18
(1966-03-18) Beets, D.J.
Letter to H.B. Stenzel from Esther R. Applin on 1954-07-08
(1954-07-08) Applin, Esther R.
Letter to H.B. Stenzel from Gordon Gunter on 1950-09-28
(1950-09-28) Gunter, Gordon A.
Letter to H.B. Stenzel from James H. Temple on 1948-08-30
(1948-08-30) Temple, James H.
Letter to H.B. Stenzel from Pat Patterson on 1954-11-14
(1954-11-14) Patterson, Pat
Letter to H.B. Stenzel from Remington Kellogg on 1931-04-13
(1931-04-13) Kellogg, Remington